<PAGE>   1
                                                   SIGNATURE COPY - JUNE 3, 1998

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                             ACQUISITION AGREEMENT


                                  DATED AS OF

                                  JUNE 3, 1998


                                     AMONG


                             REDLAND QUARRIES INC.,

                              3489264 CANADA INC.,

                              3489949 CANADA INC.,

                              LAFARGE CANADA INC.,

                                      AND

                                  LAFARGE S.A.

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<PAGE>   2
                               TABLE OF CONTENTS
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ARTICLE I
         DEFINITIONS AND INTERPRETATION
         1.1     Definitions  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
         1.2     Schedules  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  13
         1.3     Arm's Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
         1.4     Business Days  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
         1.5     Statutory Instruments  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
         1.6     Provincial Tax Legislation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15
         1.7     Accounting Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15
         1.8     Liabilities and Obligations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15

ARTICLE II
         PURCHASE AND SALE OF PURCHASED ASSETS
         2.1     Purchase and Sale of Purchased Assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15
         2.2     Excluded Assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
         2.3     Assumed Liabilities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
         2.4     Excluded Liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
         2.5     Non-Assignable Contracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
         2.6     Asset Purchase Price . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
         2.7     Payment of Asset Purchase Price  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
         2.8     Stated Capital Account . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  18
         2.9     Allocation of Consideration  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  18
         2.10    Election under subsection 85(1) of ITA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  18
         2.11    Election under section 22 of ITA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
         2.12    Election under subsection 167(1) of ETA  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
         2.13    Transfer Taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
         2.14    Adjustment of Elected Amount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  20
         2.15    Working Capital Statement  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  20

ARTICLE III
         PURCHASE AND SALE OF PURCHASED SHARES
         3.1     Purchase and Sale of Purchased Shares  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
         3.2     Share Purchase Price . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
         3.3     Payment of Share Purchase Price  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
         3.4     Stated Capital Account . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
         3.5     Election under subsection 85(1) of ITA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
         3.6     Share Purchase Price Adjustment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23

ARTICLE IV
         REDEMPTION OF PREFERENCE SHARES
         4.1     Redemption of Preference Shares  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  24
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         4.2     Payment of Redemption Price  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  24

ARTICLE V
         REPRESENTATIONS AND WARRANTIES OF SELLER AND LAFARGE S.A.
         5.1     Corporate Organization and Qualification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  24
         5.2     Corporate Authority  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  25
         5.3     Capital Stock  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  25
         5.4     Sufficiency of Assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  26
         5.5     Conflicts and Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27
         5.6     Tax Returns  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27
         5.7     Legal Proceedings and Governmental Compliance  . . . . . . . . . . . . . . . . . . . . . . . . . . .  27
         5.8     Labour and Employment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  29
         5.9     Employee Benefit Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  29
         5.10    Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32
         5.11    Consents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32
         5.12    Ownership of Assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32
         5.13    Material Adverse Change  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33
         5.14    Reserves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33
         5.15    Contracts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33
         5.16    Other Contingent Liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  35
         5.17    Inventory  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  35
         5.18    Accounts Receivable  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  35
         5.19    Affiliate Transactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36
         5.20    Customers and Suppliers  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36
         5.21    Insurance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36
         5.22    Intellectual Property  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36
         5.23    Condition of Assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36
         5.24    Purchased Assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36
         5.25    Location of Assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37
         5.26    Real Property. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37
         5.27    Guarantees and Indebtedness  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37
         5.28    Material Contracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37
         5.29    No Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37
         5.30    Expropriation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37
         5.31    Residence  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  38
         5.32    GST Registration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  38
         5.33    Tax Matters  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  38
         5.34    Worker's Compensation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  38
         5.35    Health and Safety  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  38
         5.36    Consents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  38
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ARTICLE VI
         REPRESENTATIONS AND WARRANTIES OF SHARE ACQUIROR AND LAFARGE CANADA
         6.1     Corporate Organization and Qualification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  39
         6.2     Corporate Authority  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  39
         6.3     Conflicts and Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  39
         6.4     Consents and Approvals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  40
         6.5     GST Registration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  40
         6.6     Funds for the Acquisition  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  40

ARTICLE VII
         CERTAIN COVENANTS OF THE PARTIES
         7.1     Conduct of the Seller and Lafarge S.A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  41
         7.2     Forbearances by Seller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  41
         7.3     Access and Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  42
         7.4     Current Information  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  43
         7.5     Satisfaction of Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  43
         7.6     Public Announcements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  44
         7.7     Further Assurances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  45
         7.8     Notice of Breaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  45
         7.9     Access to Books, Records and Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  45
         7.10    Delivery of Books and Records  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  46
         7.11    Lafarge S.A. Guarantee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  46
         7.12    Deleted  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  46
         7.13    Bulk Sales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  46
         7.14    Removal of Purchased Assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  47
         7.15    Retail Sales Tax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  47
         7.16    Consents Required in Contracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  47
         7.17    Employees  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  47
         7.18    Workers' Compensation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  50
         7.19    Group Plans  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  51
         7.20    Pension Plans  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  51
         7.21    Revised Dewatering Permit  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  59
         7.22    Repayment of Obligations to the Companies  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  63
         7.23    Lease of Lime Plant Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  63

ARTICLE VIII
         CONDITIONS TO THE TRANSACTIONS
         8.1     Condition to the Obligations of Each Party . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  63
         8.2     Conditions to the Obligations of Seller and Lafarge S.A. . . . . . . . . . . . . . . . . . . . . . .  64
         8.3     Conditions to the Obligations of Share Acquiror and Lafarge Canada . . . . . . . . . . . . . . . . .  65

ARTICLE IX
         TERMINATION
         9.1     Termination  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  67
         9.2     Effect of Termination  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  67
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ARTICLE X
         CLOSING
         10.1    Closing  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  68

ARTICLE XI
         SURVIVAL; INDEMNIFICATION
         11.1    Survival of Representations, Warranties and Covenants  . . . . . . . . . . . . . . . . . . . . . . .  68
         11.2    Indemnity by Seller  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  69
         11.3    Indemnity by Lafarge Canada  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  71
         11.4    Limitations  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  71
         11.5    Exclusive Remedies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  72
         11.6    Arbitration  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  72

ARTICLE XII
         MISCELLANEOUS
         12.1    Entire Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  73
         12.2    Notices  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  73
         12.3    Amendments; No Waivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  74
         12.4    Expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  75
         12.5    Successors and Assigns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  75
         12.6    Certain Interpretive Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  75
         12.7    Governing Law  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  76
         12.8    Counterparts; Effectiveness  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  76
         12.9    Confidentiality  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  76
         12.10   Severability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  76
</TABLE>

                 Schedule 1.1               - Agreed Working Capital Amount
                 Schedule 1.1(k)            - Assumption Agreement
                 Schedule 1.1(t)            - Collective Agreements
                 Schedule 1.1(w)            - Contracts
                 Schedule 1.1(cc)           - Equipment Leases
                 Schedule 1.1(ee)(ii)       - Lime Plant Site
                 Schedule 1.1(ee)(ii)B      - Lime Plant Assets
                 Schedule 1.1(ee)(iii)      - Operating Systems
                 Schedule 1.1(ee)(iv)       - Moxley Road Property Description
                 Schedule 1.1(ee)(v)        - Brow Landfill Site Description
                 Schedule 1.1(ff)(x)        - Excepted Excluded Liabilities
                 Schedule 1.1(mm)           - Group Plans
                 Schedule 1.1(rr)           - Intellectual Property Rights
                 Schedule 1.1(aaa)          - Licenses
                 Schedule 1.1(ggg)          - Non-Competition Agreement from
                                              Seller and Lafarge S.A.
                 Schedule 1.1               - Agreed Working Capital Amount





                                      (iv)
<PAGE>   6


                 Schedule 1.1(k)            - Assumption Agreement
                 Schedule 1.1(t)            - Collective Agreements
                 Schedule 1.1(w)            - Contracts
                 Schedule 1.1(cc)           - Equipment Leases
                 Schedule 1.1(ee)(ii)       - Lime Plant Site
                 Schedule 1.1(ee)(ii)B      - Lime Plant Assets
                 Schedule 1.1(ee)(iii)      - Operating Systems
                 Schedule 1.1(ee)(iv)       - Moxley Road Property Description
                 Schedule 1.1(ee)(v)        - Brow Landfill Site Description
                 Schedule 1.1(ff)(x)        - Excepted Excluded Liabilities
                 Schedule 1.1(mm)           - Group Plans
                 Schedule 1.1(rr)           - Intellectual Property Rights
                 Schedule 1.1(aaa)          - Licenses
                 Schedule 1.1(jjj)          - Pension Plans
                 Schedule 1.1(nnn)(iv)      - Fixed Assets and Equipment
                 Schedule 1.1(nnn)(xiii)    - Other Purchased Assets
                 Schedule 1.1(ooo)(i)       - North Quarry Site
                 Schedule 1.1(ooo)(ii)      - South Quarry Site
                 Schedule 1.1(ooo)(iii)     - Queenston Quarry Site
                 Schedule 1.1(ooo)(iv)      - Aggregate / Lime Processing Site
                 Schedule 1.1(www)(a)       - Persons with Knowledge - Seller
                 Schedule 1.1(www)(b)       - Persons with Knowledge - Lafarge
                                              Canada et. al.
                 Schedule 2.6               - Fair Market Values of Purchased 
                                              Assets
                 Schedule 3.3               - Articles of Incorporation of
                                              Share Acquiror
                 Schedule 5.4               - Qualification re: Sufficiency of
                                              Assets
                 Schedule 5.5               - Conflicts and Defaults of Seller
                 Schedule 5.7(a)            - Pending Legal Proceedings
                 Schedule 5.7(b)            - Governmental Compliance
                 Schedule 5.7(c)            - Missing Licenses /
                                              Transferability of Licenses
                 Schedule 5.7(d)            - Environmental Compliance
                 Schedule 5.8               - Employment  Contracts
                 Schedule 5.9               - Benefit Plans
                 Schedule 5.10              - Financial Statements
                 Schedule 5.11              - Required Filings and Permits
                 Schedule 5.12(a)           - Liens
                 Schedule 5.13              - Material Adverse Change
                 Schedule 5.14              - Reserves
                 Schedule 5.15              - Material Agreements /
                                              Transferability of Agreements
                 Schedule 5.16              - Assumed Liabilities
                 Schedule 5.18              - Exceptions to Accounts Receivable
                 Schedule 5.19              - Affiliate Transactions
                 Schedule 5.20              - Customers and Suppliers
                 Schedule 5.25              - Locations of Material Tangible
                                              Assets
                 Schedule 5.27              - Guarantees and Indemnitees





                                      (v)
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                 Schedule 6.3               - Conflicts and Defaults of Share
                                              Acquiror and Lafarge Canada
                 Schedule 7.1               - Out of the Ordinary Course
                                              Exceptions
                 Schedule 7.17              - Employees
                 Schedule 7.20(a)           - Form of Pension Assumption
                                              Agreement
                 Schedule 7.20(b)           - Actuarial Methods, Assumptions
                                              and Principles
                 Schedule 7.23              - Form of Lime Plant Lease
                 Schedule 8.2(g)            - Form of Opinion of McCarthy
                                              Tetrault
                 Schedule 8.3(e)            - Form of Lafarge S.A. Guarantee
                 Schedule 8.3(i)            - Form of Opinion of Miller Thomson
                                              and Form of opinion of
                                              Andre-Gilles Taithe, corporate
                                              counsel to Lafarge S.A.





                                      (vi)

<PAGE>   8
                                                   SIGNATURE COPY - JUNE 3, 1998


                             ACQUISITION AGREEMENT

ACQUISITION AGREEMENT (this "AGREEMENT") dated as of June 3, 1998, among
Redland Quarries Inc., a corporation incorporated under the laws of the
Province of Ontario ("SELLER"), 3489264 Canada Inc., a Canadian corporation
("ASSET ACQUIROR"), 3489949 Canada Inc., a Canadian corporation ("SHARE
ACQUIROR"),  Lafarge Canada Inc., a Canada corporation ("LAFARGE CANADA") and
Lafarge S.A., a corporation organized and existing under the laws of France
("LAFARGE S.A.")

                                   RECITALS:

A.       The Seller carries on the businesses at the Dundas Site and the
Queenston Quarry Site (both as defined herein) of operating quarries and
extracting and processing construction aggregate and metallurgical limestone
therefrom (the "AGGREGATE BUSINESS") and at and from the Dundas Site of the
manufacturing, processing and burning of limestone to produce lime products and
the distribution and sale of lime products and the production and sale of
limestone by- products (the "LIME BUSINESS").

B.       The Seller has conveyed legal title to the Purchased Properties (as
defined herein) to Lafarge Canada as bare trustee for the Seller and its
successors and assigns.

C.       The Seller has agreed to sell to the Asset Acquiror and the Asset
Acquiror has agreed to purchase from the Seller the assets, property and
undertakings of and pertaining to the Aggregate Business which are more
specifically described in this Agreement, upon and subject to the terms and
conditions of this Agreement.

D.       The Seller has agreed to sell to the Share Acquiror and the Share
Acquiror has agreed to purchase from the Seller all of the issued and
outstanding shares in the Asset Acquiror subsequent to the purchase and sale
referred to in recital B, upon and subject to the terms and conditions of this
Agreement.
<PAGE>   9
                                                   SIGNATURE COPY - JUNE 3, 1998


         NOW THEREFORE in consideration of the representations, warranties,
covenants and agreements set forth herein, and for other good and valuable
consideration the receipt and sufficiency of which are hereby acknowledged, the
parties hereto hereby agree as follows:

                                   ARTICLE I

                         DEFINITIONS AND INTERPRETATION

1.1      Definitions.  The following terms used herein shall have the following
meanings:

(a)      "ACCEPTING EMPLOYEE" means any Employee (as defined in Section 7.17)
who accepts the offer of employment extended by Asset Acquiror or Lafarge
Canada, as the case may be, under Section 7.17(a) or who otherwise becomes
employed by Asset Acquiror or Lafarge Canada on the Closing Date in accordance
with Section 7.17(a).

(b)      "ACT" means the Securities Act (Ontario), as amended, and the rules
and regulations promulgated thereunder.

(c)      "AFFILIATE" means, with respect to any Person, any other Person who is
directly or indirectly controlling, controlled by or under the common control
with such Person.  For the purposes of this definition, the term "control,"
when used with respect to any Person, means the possession, directly or
indirectly, of the power to direct or cause the direction of the management and
policies of such Person, whether through the ownership of voting securities, by
contract or otherwise.

(d)      "AFFILIATE TRANSACTIONS" has the meaning set forth in Section 5.18.

(e)      "AGGREGATE BUSINESS" has the meaning ascribed in the recitals to this
Agreement.

(f)      "AGGREGATE LOSSES" has the meaning set forth in Section 11.4(a).

(g)      "AGGREGATE/LIME PROCESSING SITE" has the meaning set forth in
Section 1.1(ooo)(iv).

(h)      "AGREED WORKING CAPITAL AMOUNT" means, for the Aggregate Business, the
amount set forth in Schedule 1.1 calculated in the manner set forth on Schedule
1.1.

(i)      "AGREEMENT" means this Acquisition Agreement, together with the
Schedules hereto.

(j)      "ASSET ACQUIROR" means 3489264 Canada Inc., a corporation incorporated
under the laws of Canada.

(k)      "ASSET PURCHASE PRICE" means the total purchase price to be paid by
the Asset Acquiror to the Seller for the Purchased Assets, all as provided in
Section 2.6.





                                       2
<PAGE>   10
                                                   SIGNATURE COPY - JUNE 3, 1998


(l)      "ASSUMED LIABILITIES" means the Disclosed Liabilities existing,
incurred, due or accruing due on or before the Closing Date.

(m)      "ASSUMPTION AGREEMENT" means the assumption and indemnity agreement to
be issued by the Asset Acquiror to the Seller in the form attached as Schedule
1.1(k).

(n)      "BENEFIT PLANS" has the meaning set forth in Section 5.9.

(o)      "BROW SITE" has the meaning set forth in Section 1.1(ee)(v).

(p)      "BUSINESS DAY" means a day (excluding Saturday and Sunday) on which
banks generally are open for the transaction of normal business in Toronto,
Ontario.

(q)      "CLOSING" has the meaning set forth in Section 10.1.

(r)      "CLOSING DATE" has the meaning set forth in Section 10.1.

(s)      "CLOSING DOCUMENTS" means collectively the documents referred to in
Article 7.

(t)      "COLLECTIVE AGREEMENTS" means the collective agreements and related
documents including all benefit agreements, letters of understanding, letters
of intent and other written communications with bargaining agents which impose
any obligations upon the Seller or set out the understanding of the parties
with respect to the meaning of any provisions of the collective agreements
entered into by the Seller with respect to the Aggregate Business which are
listed in Schedule 1.1(t).

(u)      "COMMON SHARES" has the meaning set forth in Section 2.7(b).

(v)      "CONFIDENTIALITY AGREEMENT" means the Confidentiality Agreement
between Lafarge S.A. and Lafarge Corporation, with respect to, among other
things, the transactions addressed in this Agreement and under the United
States Stock Purchase Agreement.

(w)      "CONTRACTS" means the contracts, agreements, commitments, entitlements
and engagements of the Seller relating to the Aggregate Business and the
Purchased Assets including those listed in Schedule 1.1(w) and the regulator
site lease and agreement dated the 6th day of December, 1995 between Seller and
Union Gas Limited and all unfilled orders from customers and forward
commitments and unfilled orders for supplies or materials incurred in the
ordinary course of business of the Seller and relating to the Aggregate
Business and the Purchased Assets and all other contracts relating to the
Aggregate Business and the Purchased Assets whether or not described in
Schedule 1.1(w).

(x).2    "DISCLOSED LIABILITIES" has the meaning ascribed thereto in Section
5.16.





                                       3
<PAGE>   11
                                                   SIGNATURE COPY - JUNE 3, 1998


(x)      "DUNDAS SITE" means the freehold property owned by the Seller in
Flamborough, Ontario which comprises the North Quarry Site, the South Quarry
Site and the Aggregate / Lime Processing Site.

(y)      "ELECTED AMOUNT" in respect of a particular property means the amount
elected pursuant to subsection 85(1) of the ITA in respect thereof pursuant to
the terms of this Agreement.

(z)      "EMPLOYEES" has the meaning ascribed in Section 7.17.

(aa)     "ENVIRONMENTAL CLAIM" means, with respect to any Person, any action,
cause of action, investigation, suit, proceeding, judgment, award, fine,
penalty, assessment or written notice or claim by any person or entity alleging
potential liability (including, without limitation, potential liability for
investigatory costs, clean-up costs, governmental response costs, natural
resources damages, property damages, personal injuries, or penalties) arising
out of, based on or resulting from (a) the presence, discharge, migration or
release into the environment, of any Hazardous Material at any location,
whether or not owned or operated by such Person; (b) the generation, handling,
use, treatment, recycling, storage, disposal or transport of any Hazardous
Material; or (c) any violation of an Environmental Law.

(bb)     "ENVIRONMENTAL LAWS" has the meaning set forth in Section 5.7.

(cc)     "EQUIPMENT LEASES" means those equipment leases, conditional sales
contracts, title retention agreements and other agreements between the Seller
and third Persons relating to equipment used by the Seller in connection with
the Aggregate Business that are listed in Schedule 1.1(cc).

(dd)     "ETA" means the Excise Tax Act (Canada) as amended from time to time;

(ee)     "EXCLUDED ASSETS" means the following assets, property and undertaking
of Seller:

         (i)     all cash, bank balances, moneys in possession of banks and
                 other depositaries, term or time deposits and similar cash
                 items of, owned or held by or for the account of the Seller;

         (ii)    the assets, undertaking and property (including goodwill) of,
                 used in or relating to the Lime Business which comprise the
                 following assets, undertaking and property:

                 1)       those assets, undertaking and property of, used in or
                          relating to the Lime Business that are otherwise
                          described in this Section 1.1(ee), and





                                       4
<PAGE>   12
                                                   SIGNATURE COPY - JUNE 3, 1998


                 2)       the leasehold title to the lands and premises
                          together with all rights of way, easements and
                          similar rights appurtenant thereto as described in
                          Schedule 1.1(ee)(ii) (the "LIME PLANT SITE") and all
                          rights set out in the Lime Plant Lease (as defined in
                          Section 7.23), and

                 3)       the beneficial right, title and interest, and to the
                          extent possible the legal right, title and interest,
                          in and to all kilns, plant, equipment, machinery,
                          chattels, vehicles, buildings, sidings, parking lots,
                          roadways, structures, erections, improvements,
                          appurtenances and fixtures situate at or on or
                          forming part of the Lime Plant Site, and

                 4)       the assets, undertaking and property of, used in or
                          relating to the Lime Business as set forth in the
                          Financial Statements, and

                 5)       the accounts receivable, inventory, prepaid expenses
                          and other current assets of, used in or relating to
                          the Lime Business which have accrued, been created or
                          arisen in the ordinary and usual course of business
                          since January 1, 1998, and

                 6)       the contracts, agreements, commitments, entitlements
                          and engagements of the Seller relating to the Lime
                          Business and all unfilled orders from customers and
                          forward commitments and unfilled orders for supplies
                          or materials incurred in the ordinary course of
                          business of the Seller and relating to the Lime
                          Business and the equipment leases, conditional sales
                          contracts, title retention agreements and other
                          agreements between the Seller and third Persons
                          relating to equipment used by the Seller in
                          connection with the Lime Business, and

                 7)       the other assets, undertaking and property of, used
                          in or relating to the Lime Business that are listed
                          or described in Schedule 1.1(ee)(ii)B;

         (iii)   the administrative and financial operating systems relating to
                 the Aggregate Business and/or the Lime Business, the
                 components of which are described in Schedule 1.1(ee)(iii);





                                       5
<PAGE>   13
                                                   SIGNATURE COPY - JUNE 3, 1998


         (iv)    the freehold title to the land and the office building
                 municipally known as 447 Moxley Road, Dundas, Ontario (the
                 "MOXLEY ROAD SITE"), forming part of the Dundas Site, and all
                 contents thereof as described in Schedule 1.1(ee)(iv);

         (v)     the freehold title to the land, building, structures and
                 improvements known as the Brow Landfill Site (the "BROW
                 SITE"), forming part of the Dundas Site as described in
                 Schedule 1.1(ee)(v);

         (vi)    the leasehold interest, including all fixtures and
                 improvements relating to the lease of the Seller, as tenant,
                 of the fifth floor and part of the third floor of the office
                 building at 605 James Street North, Hamilton, Ontario (the
                 "LEASE") and all chattels, inventory, furniture, machinery,
                 equipment and supplies located on or at those premises;

         (vii)   indebtedness of, and all shares, securities or other interests
                 in, and all assets and liabilities of Redland France S.A.;

         (viii)  the corporate, financial, taxation and other records of the
                 Seller not pertaining exclusively or primarily to the
                 Aggregate Business or Purchased Assets;

         (ix)    all sales, excise or other similar registrations issued to or
                 held by the Seller, whether in respect of the Aggregate
                 Business or otherwise, but excluding the Scheduled Permits;
                 and

         (x)     all income taxes recoverable.

(ff)     "EXCLUDED LIABILITIES" means all debts, liabilities and obligations
(whether absolute, contingent, accrued or otherwise) of the Seller existing,
incurred, due or accruing due on or before the Closing Date, but specifically
excluding the Assumed Liabilities.  Subject to the exception of the Assumed
Liabilities, the Excluded Liabilities, include, without limitation, the
following:

         (i)     all deferred income taxes of the Seller;

         (ii)    except as specifically contemplated in Section 2.13 of this
                 Agreement or as set out in Schedule 5.16, all Taxes collected,
                 collectible or payable by the Seller;

         (iii)   those liabilities and obligations, whether accrued, absolute
                 or contingent, liquidated or unliquidated or disclosed or
                 undisclosed, which relate to the Excluded Assets;





                                       6
<PAGE>   14
                                                   SIGNATURE COPY - JUNE 3, 1998


         (iv)    all costs and expenses of the Seller incurred in the
                 preparation, execution and delivery of this Agreement and the
                 transactions contemplated by this Agreement;

         (v)     any liability of the Seller arising on or after the date of
                 this Agreement out of any misrepresentation or breach of any
                 warranty or covenant of the Seller contained in this Agreement
                 or any other document delivered pursuant hereto;

         (vi)    any obligation or liability of the Seller relating to the Brow
                 Site, including Environmental Claims;

         (vii)   any liability with respect to the manufacture, processing and
                 burning of  limestone on or before the Closing Date, including
                 with respect to any lime residue or waste by-product arising
                 therefrom on or before the Closing Date;

         (viii)  except as specifically contemplated in this Agreement, any
                 obligation or liability of the Seller under the Pension Plans;

         (ix)    any liability of the Seller to any bank or other financial
                 institution by way of loan or other credit facility; and

         (x)     any liability of the Seller to its shareholders, Affiliates or
                 associates (as defined in the Act) or any other Person not
                 dealing at arm's length with any of them including, for
                 greater certainty, the liability of the Seller to Redland
                 International, but excluding trade accounts payable for goods
                 or services provided in connection with the Aggregate Business
                 as described in Schedule 1.1(ff)(x);

(gg)     "FINANCIAL STATEMENTS" means the non-consolidated financial statements
of the Seller for its fiscal period ended on December 31, 1997.

(hh)     "FIRM" has the meaning set forth in Section 2.15(f).

(ii)     "FIRST CLOSING TIME" means 10:00 o'clock in the forenoon on the
Closing Date or such other time on such date as the Parties may agree as the
time at which the Closing shall take place.

(jj)     "GAAP" has the meaning ascribed in Section 1.7.

(kk)     "GOVERNMENTAL ENTITY" means any national, federal, state, local,
provincial or municipal government, court, administrative agency, board, body,
instrumentality or commission or other governmental or other regulatory
authority or agency of Canada, England, the United States or France or any
state, province, municipality or any subdivision thereof.





                                       7
<PAGE>   15
                                                   SIGNATURE COPY - JUNE 3, 1998


(ll)     "GROUP PLAN" means the group insurance, deferred compensation and
other benefit plans or arrangements maintained by the Seller that are listed on
Schedule 1.1(mm);

(mm)     "GST" means the Goods and Services Tax payable under the ETA.

(nn)     "GUARANTEE" has the meaning set forth in Section 7.11.

(oo)     "HAZARDOUS MATERIALS" means any pollutant, waste, toxic substance,
radioactive substance, dangerous substance or dangerous goods as defined or
identified in or pursuant to any Environmental Law.

(pp)     "INCORPORATOR SHARE" means the one common share in the capital stock
of Asset Acquiror issued initially to the Seller.

(qq)     "INTELLECTUAL PROPERTY RIGHTS" means all patents and inventions, trade
marks, trade names and styles, logos and designs, trade secrets, technical
information, engineering procedures, designs, formulae, technology, industrial
property, knowhow and processes (whether confidential or otherwise), software,
and other industrial property (including applications for any of these) in each
case used or employed in the operation of the Aggregate Business as presently
constituted and which are described in Schedule 1.1(rr).

(rr)     "INVENTORIES" means all inventories of every kind and nature and
wheresoever situate owned by the Seller and pertaining to the Aggregate
Business including, without limitation, all inventories of raw materials,
work-in-progress, finished goods, operating supplies and packaging materials of
or pertaining to the Aggregate Business.

(ss)     "ITA" means the Income Tax Act (Canada) as amended from time to time.

(tt)     "LAFARGE CANADA" means Lafarge Canada Inc., a corporation organized
and existing under the laws of Canada.

(uu)     "LAFARGE CORPORATION" means Lafarge Corporation, a corporation
organized and existing under the laws of the State of Maryland.

(vv)     "LAFARGE S.A." means Lafarge S.A., a corporation organized and
existing under the laws of France.

(ww)     "LAWS" means all applicable laws, regulations, rules, judgments,
rulings, writs, injunctions, orders and decrees of Governmental Entities.

(xx)     "LEASE" has the meaning ascribed thereto in Section 1.1(ee)(vi).





                                       8
<PAGE>   16
                                                   SIGNATURE COPY - JUNE 3, 1998


(yy)     "LIABILITIES" means any and all claims, actions, suits, demands,
assessments, judgments, losses, liabilities, damages, costs, royalties,
payments, license fees and expenses (including interest, penalties, attorneys'
fees, accounting fees and investigation costs).

(zz)     "LICENSES" means all licenses, registrations, qualifications, permits,
consents, authorizations and approvals, issued by any Governmental Entity,
relating to the Aggregate Business, including those listed in Schedule
1.1(aaa), together with all applications for any of the foregoing.

(aaa)    "LIEN" means any mortgage, lien, pledge, charge, security interest,
restriction on voting or transfer, or other encumbrance.

(bbb)    "LIME BUSINESS" has the meaning ascribed in the recitals to this
Agreement.

(ccc)    "LIME PLANT SITE" has the meaning set forth in Section 1.1(ee)(ii).

(ddd)    "LIME SUPPLY AGREEMENT" has the meaning ascribed thereto in Section
8.2.

(eee)    "MATERIAL ADVERSE EFFECT" means, with respect to the Aggregate
Business, such state of facts, event, change or effect as has had, or would
reasonably be expected to have, a material adverse effect (i) on the business,
results of operations, or financial condition of the Aggregate Business, or
(ii) on the ability of Seller to consummate the transactions contemplated by
this Agreement.

(fff)    "MOXLEY ROAD SITE" has the meaning set forth in Section 1.1(ee)(iv).

(ggg)    Deleted.

(hhh)    "NORTH QUARRY SITE" has the meaning set forth in Section 1.1(ooo)(i).

(iii)    "PARTIES" means the Seller, the Asset Acquiror, the Share Acquiror,
Lafarge Canada and Lafarge S.A., collectively, and "PARTY" means any one of
them.

(jjj)    "PENSION PLAN(S)" means the pensions plans maintained by the Seller
for the benefit of its employees or former employees as listed in Schedule
1.1(jjj).

(kkk)    "PERMITTED LIENS" has the meaning set forth in Section 5.12.

(lll)    "PERSON" means an individual, corporation, body corporate,
partnership, limited liability company, association, trust or other entity or
organization, including without limitation, a Governmental Entity.

(mmm)    "PREFERENCE SHARES" has the meaning ascribed in Section 3.3.

(nnn)    "PURCHASED ASSETS" means all right, title, benefit and interest of the
Seller in and to the assets, undertaking and properties of the Seller relating
to the Aggregate Business, but specifically





                                       9
<PAGE>   17
                                                   SIGNATURE COPY - JUNE 3, 1998


excluding the Excluded Assets.  Subject to the exception of the Excluded
Assets, the Purchased Assets include, without limitation;

         (i)     REAL PROPERTY - all of the Purchased Properties;

         (ii)    INVENTORIES - all the Inventories;

         (iii)   CONTRACTS AND EQUIPMENT LEASES - the full benefit and
                 advantage of the Contracts and the Equipment Leases and all
                 options, including, without limitation, options to purchase,
                 under the Contracts or Equipment Leases;

         (iv)    ASSETS, EQUIPMENT, ETC. - all assets, machines, machinery,
                 equipment, fixtures, furniture, furnishings, vehicles, dies,
                 tools, and other tangible property and facilities owned or
                 held by the Seller and used in the Aggregate Business,
                 including those  described in Schedule 1.1(nnn)(iv);

         (v)     the full benefit of all manufacture, service or licence
                 agreements to which Seller is entitled in relation to any
                 Equipment Leases or other assets or machinery forming part of
                 the Purchased Assets;

         (vi)    GOODWILL OF AGGREGATE BUSINESS - the right, title and interest
                 of the Seller in the goodwill of the Aggregate Business;

         (vii)   PREPAID EXPENSES - all prepaid expenses and deposits
                 including, without limitation, taxes, business taxes, rents,
                 telephone and insurance incurred by the Seller in connection
                 with the Aggregate Business but excluding income, capital and
                 other taxes which are personal to the Seller and not incurred
                 in connection with the Aggregate Business;

         (viii)  ACCOUNTS RECEIVABLE - all accounts receivable, bills
                 receivable, trade accounts, book debts, and other amounts due,
                 owing or accruing due to the Seller in connection with the
                 Aggregate Business, including for greater certainty, the
                 benefit of all security (including cash deposits), guarantees
                 and other collateral held by the Seller in respect of any
                 accounts receivable;

         (ix)    INTELLECTUAL PROPERTY RIGHTS - all right, title and interest
                 of the Seller in the Intellectual Property Rights;





                                       10
<PAGE>   18
                                                   SIGNATURE COPY - JUNE 3, 1998


         (x)     INVESTMENTS - the 3,750 issued and outstanding common shares
                 of National Slag Limited;

         (xi)    LICENSES - all the Licenses;

         (xii)   BOOKS AND RECORDS - all business books and records used in the
                 conduct of the Aggregate Business, including without
                 limitation, all financial, operating, inventory, legal,
                 personnel, payroll, and customer records and all sales and
                 promotional literature, correspondence and files and all plans
                 and specifications, if any, relating to the Real Property or
                 the plant, buildings and improvements thereon; and,

         (xiii)  GENERAL - the assets relating to the Aggregate Business listed
                 in Schedule 1.1(nnn)(xiii).

(ooo)    "PURCHASED PROPERTIES" means the freehold, leasehold, and other
interests (whether beneficial or legal or both) in real and immoveable
properties owned by or on behalf of or used by the Seller in connection with
the Aggregate Business, and described as follows:

         (i)     the freehold lands and premises described in Schedule
                 1.1(ooo)(i) (the "NORTH QUARRY SITE");

         (ii)    the freehold lands and premises described in Schedule
                 1.1(ooo)(ii) (the "SOUTH QUARRY SITE");

         (iii)   the freehold lands and premises described in Schedule
                 1.1(ooo)(iii) (the "QUEENSTON QUARRY SITE");

         (iv)    the freehold lands and premises described in Schedule
                 1.1(ooo)(iv) (the "AGGREGATE/LIME PROCESSING SITE")

and all plant, buildings, sidings, parking lots, roadways, structures,
erections, improvements, appurtenances and fixtures situate on or forming part
of such lands and premises, except for the Excluded Assets.

(ppp)    "PURCHASED SHARES" means, collectively, the Incorporator Share and the
Common Shares.

(qqq)    "QUEENSTON QUARRY SITE" has the meaning set forth in Section
1.1(ooo)(iii).

(rrr)    "REAL PROPERTIES" means, collectively, the Purchased Properties, the
Moxley Road Site and the Brow Site.





                                       11
<PAGE>   19
                                                   SIGNATURE COPY - JUNE 3, 1998


(sss)    "REDEMPTION PRICE" means the total redemption price for the Preference
Shares, being an amount equal to the Share Purchase Price.

(ttt)    "SCHEDULED PERMITS" has the meaning set forth in Section 5.7(c).

(uuu)    "SECOND CLOSING TIME" means 10:30 o'clock in the forenoon on the
Closing Date or such other time on such date as the Parties may agree as the
time at which the Closing shall take place.

(vvv)    "SELLER" means Redland Quarries Inc., a corporation organized and
existing under the laws of the Province of Ontario.

(www)    "SHARE ACQUIROR" means 3489949 Canada Inc., a corporation incorporated
under the laws of Canada.

(xxx)    "SHARE PURCHASE PRICE" means the purchase price to be paid by the
Share Acquiror to the Seller for the Purchased Shares, all as provided in
Section 3.2.

(yyy)    "SOUTH QUARRY SITE" has the meaning set forth in Section 1.1(ooo)(ii).

(zzz)    "TAXES" means any Canadian, United States, United Kingdom, French or
other foreign, federal, state, local, provincial or municipal net income, gross
income, gross receipts, sales, goods and services, use, ad valorem, transfer,
franchise, profits, withholding, capital, payroll (including, for greater
certainty, Canada Pension Plan and Employment Insurance Act premiums),
employment, excise, stamp, occupation, property, customs, duties or other type
of fiscal levy and all other taxes of any kind whatsoever, together with any
interest, penalties or fines imposed or assessed with respect thereto and "TAX"
shall have a corresponding meaning.

(aaaa)   "THIRD CLOSING TIME" means 11:00 o'clock in the forenoon on the
Closing Date or such other time on such date as the Parties may agree as the
time at which the Closing shall take place.

(bbbb)   "TO THE KNOWLEDGE" or similar phrases, when used in reference to:

         (A)     the Seller means the knowledge of persons identified in
                 Schedule 1.1(www) (a); and,

         (B)     the Asset Acquiror, Share Acquiror or Lafarge Canada means the
                 knowledge of persons identified in Schedule 1.1(www)(b).

(cccc)   "UNADJUSTED PURCHASE PRICE" has the meaning set forth in Section 3.2.

(dddd)   "UNITED STATES STOCK PURCHASE AGREEMENT" has the meaning set forth in
Section 8.1.

(eeee)   "WORKING CAPITAL AMOUNT" means the amount for the Aggregate Business
calculated in the manner set forth on Schedule 1.1, excluding, however, an
amount equal to the amount (calculated





                                       12
<PAGE>   20
                                                   SIGNATURE COPY - JUNE 3, 1998


as of the date of the particular acquisition) of any working capital purchased,
or assumed, on or after January 1, 1998 and before the Closing Date in
connection with the acquisition by Seller of an aggregate business as a going
concern, using Closing Date values obtained from the Working Capital Statement.

(ffff)   "WRITTEN NOTICE" has the meaning set forth in Section 11.1.

(gggg)   "WORKING CAPITAL STATEMENT" means the working capital statement for
the Aggregate Business as at the Closing Date, prepared in accordance with
Section 2.15.

1.2      Schedules.  The following Schedules are an integral part of this
Agreement:

               Schedule 1.1             -   Agreed Working Capital Amount
               Schedule 1.1(k)          -   Assumption Agreement
               Schedule 1.1(t)          -   Collective Agreements
               Schedule 1.1(w)          -   Contracts
               Schedule 1.1(cc)         -   Equipment Leases
               Schedule 1.1(ee)(ii)     -   Lime Plant Site
               Schedule 1.1(ee)(ii)B    -   Lime Plant Assets
               Schedule 1.1(ee)(iii)    -   Operating Systems
               Schedule 1.1(ee)(iv)     -   Moxley Road Property Description
               Schedule 1.1(ee)(v)      -   Brow Landfill Site Description
               Schedule 1.1(ff)(x)      -   Excepted Excluded Liabilities
               Schedule 1.1(mm)         -   Group Plans
               Schedule 1.1(rr)         -   Intellectual Property Rights
               Schedule 1.1(aaa)        -   Licenses
               Schedule 1.1(jjj)        -   Pension Plans
               Schedule 1.1(nnn)(iv)    -   Fixed Assets and Equipment
               Schedule 1.1(nnn)(xiii)  -   Other Purchased Assets
               Schedule 1.1(ooo)(i)     -   North Quarry Site
               Schedule 1.1(ooo)(ii)    -   South Quarry Site
               Schedule 1.1(ooo)(iii)   -   Queenston Quarry Site
               Schedule 1.1(ooo)(iv)    -   Aggregate / Lime Processing Site
               Schedule 1.1(www)(a)     -   Persons with Knowledge - Seller
               Schedule 1.1(www)(b)     -   Persons with Knowledge - Lafarge 
                                            Canada et. al.
               Schedule 2.6             -   Fair Market Values of Purchased 
                                            Assets
               Schedule 3.3             -   Articles of Incorporation of Share
                                            Acquiror
               Schedule 5.4             -   Qualification re: Sufficiency of 
                                            Assets
               Schedule 5.5             -   Conflicts and Defaults of Seller
               Schedule 5.7(a)          -   Pending Legal Proceedings
               Schedule 5.7(b)          -   Governmental Compliance
               Schedule 5.7(c)          -   Missing Licenses/Transferability
                                            of Licenses





                                       13
<PAGE>   21
                                                   SIGNATURE COPY - JUNE 3, 1998


               Schedule 5.7(d)          -   Environmental Compliance
               Schedule 5.8             -   Employment  Contracts
               Schedule 5.9             -   Benefit Plans
               Schedule 5.10            -   Financial Statements
               Schedule 5.11            -   Required Filings and Permits
               Schedule 5.12(a)         -   Liens
               Schedule 5.13            -   Material Adverse Change
               Schedule 5.14            -   Reserves
               Schedule 5.15            -   Material Agreements/Transferability
                                            of Agreements
               Schedule 5.16            -   Assumed Liabilities
               Schedule 5.18            -   Exceptions to Accounts Receivable
               Schedule 5.19            -   Affiliate Transactions
               Schedule 5.20            -   Customers and Suppliers
               Schedule 5.25            -   Locations of Material Tangible
                                            Assets
               Schedule 5.27            -   Guarantees and Indemnitees
               Schedule 6.3             -   Conflicts and Defaults of Share
                                            Acquiror and Lafarge Canada
               Schedule 7.1             -   Out of the Ordinary Course
                                            Exceptions
               Schedule 7.17            -   Employees
               Schedule 7.20(a)         -   Form of Pension Assumption
                                            Agreement
               Schedule 7.20(b)         -   Actuarial Methods, Assumptions and
                                            Principles
               Schedule 7.23            -   Form of Lime Plant Lease
               Schedule 8.2(g)          -   Form of Opinion of McCarthy
                                            Tetrault
               Schedule 8.3(e)          -   Form of Lafarge S.A. Guarantee
               Schedule 8.3(i)          -   Form of Opinion of Miller Thomson
                                            and Form of opinion of
                                            Andre-Gilles Taithe, corporate
                                            counsel to Lafarge S.A.

1.3      Arm's Length.  For purposes of this Agreement, Persons are not dealing
"at arm's length" with one another if they would not be dealing at arm's length
with one another for purposes of the ITA.

1.4      Business Days.  Whenever any action or payment to be taken or made
under this Agreement shall be stated to be required to be taken or made on a
day other than a Business Day, such payment shall be made or such action shall
be taken on the next succeeding Business Day.

1.5      Statutory Instruments.  Unless otherwise specifically provided in this
Agreement, any reference in this Agreement to any law, by-law, rule,
regulation, order, act or statute of any government, governmental body or other
regulatory body shall be construed as a reference to those  as amended or
re-enacted from time to time or as a reference to any successor to those.





                                       14
<PAGE>   22
                                                   SIGNATURE COPY - JUNE 3, 1998


1.6      Provincial Tax Legislation.  For the purposes of this Agreement, where
the context so permits, any reference to the ITA includes a reference to any
analogous provincial legislation, any reference to any provision of the ITA
includes a reference to the corresponding provision of any such analogous
provincial legislation, any reference to Revenue Canada includes a reference to
any relevant provincial taxation authority and any reference to a filing or
similar requirement imposed under the ITA includes a reference to any
corresponding filing or requirement imposed under any such analogous provincial
legislation.

1.7      Accounting Terms.  All accounting terms not otherwise defined have the
meanings assigned to them, and all calculations are to be made and all
financial data to be submitted are to be prepared, in accordance with the
generally accepted accounting principles ("GAAP") approved from time to time by
the Canadian Institute of Chartered Accountants, or any successor institute
applied on a consistent basis.

1.8      Liabilities and Obligations.  Lafarge Canada, Asset Acquiror and Share
Acquiror acknowledge that Asset Acquiror and Share Acquiror are, or will upon
Closing, become wholly-owned subsidiaries of Lafarge Canada and that it is
essential to Seller in entering into this Agreement that the covenant of
Lafarge Canada extends to all the liabilities and obligations of Asset Acquiror
and Share Acquiror under this Agreement and the Acquiror Other Agreements.  The
Parties therefore confirm their intention, and the Parties hereby agree, that
each of Lafarge Canada, Asset Acquiror and Share Acquiror are jointly and
severally liable for the payment and performance of all the liabilities and
obligations under this Agreement and under the Acquiror Other Agreements of
Lafarge Canada, Asset Acquiror and Share Acquiror, whether or not those
liabilities and obligations are expressed as the liabilities and obligations of
one or more of them.

                                   ARTICLE II

                     PURCHASE AND SALE OF PURCHASED ASSETS

2.1      Purchase and Sale of Purchased Assets.  Upon and subject to the terms
and conditions of this Agreement, the Seller shall sell, transfer, assign and
set over to the Asset Acquiror and the Asset Acquiror shall purchase and
acquire from the Seller at the First Closing Time, the Purchased Assets for the
Asset Purchase Price payable as provided in Section 2.7.





                                       15
<PAGE>   23
                                                   SIGNATURE COPY - JUNE 3, 1998


2.2      Excluded Assets.  For greater certainty, the Excluded Assets shall be
specifically excluded from the Purchased Assets whether or not they may be
considered to form part of the property and assets of the Aggregate Business.
Within 30 days following the Closing Date, the Seller shall at its own expense
remove all tangible Excluded Assets, if any, from the premises of the Aggregate
Business except for the PH neutralization plant.

2.3      Assumed Liabilities.  The Asset Acquiror agrees to assume and become
liable only for the Assumed Liabilities at the First Closing Time by executing
and delivering the Assumption Agreement to the Seller.

2.4      Excluded Liabilities.  For greater certainty, it is understood that
the Asset Acquiror will assume no liabilities other than those described in or
forming part of the Assumed Liabilities that, without limitation, do not
include the Excluded Liabilities.

2.5      Non-Assignable Contracts.  This Agreement and any document delivered
under this Agreement shall not constitute an assignment or an attempted
assignment of any Contract, Equipment Lease or Licence contemplated to be
assigned to the Asset Acquiror under this Agreement:

         (a)     which is not assignable without the consent of a third party
                 if such consent has not been obtained and such assignment or
                 attempted assignment would constitute a breach of such
                 contract or agreement; or

         (b)     in respect of which the remedies for the enforcement of such
                 contract or agreement available to the Seller would not pass
                 to the Asset Acquiror.

         The Seller shall use its best efforts to obtain the consents of third
parties as may be necessary for the assignment of the Contracts, the Equipment
Leases and the Licenses except that the Seller shall not be obliged to make any
payments to those third parties in addition to those required to be made under
those contracts or agreements in order to obtain such consents, unless the
Asset Acquiror agrees in writing to reimburse the Seller for such payments at
the time that they are made.  To the extent that any of the foregoing items are
not assignable by their terms or where consents to their assignment cannot be
obtained as provided in this Section 2.5, such items shall be held by the
Seller in trust for the Asset Acquiror and the covenants and obligations under
those contracts or agreements shall be performed by the Asset Acquiror in the
name of the Seller and all benefits and obligations





                                       16
<PAGE>   24
                                                   SIGNATURE COPY - JUNE 3, 1998


existing therein shall be for the account of the Asset Acquiror.  The Seller
shall take or cause to be taken such action in its name or otherwise as the
Asset Acquiror may reasonably require so as to provide the Asset Acquiror with
the benefits of those contracts or agreements and to effect collection of money
to become due and payable under such items and the Seller shall promptly pay
over to the Asset Acquiror all money received by the Seller in respect of all
of the foregoing items.  Upon the Closing, the Seller and the Asset Acquiror
shall execute and deliver a general assignment of contracts, leases and
licenses agreement, under which the Seller shall authorize the Asset Acquiror,
at the Asset Acquiror's expense, to perform all of the Seller's obligations
under the foregoing items and constitute the Asset Acquiror its attorney to act
in the name of the Seller with respect to those items, and the Asset Acquiror
shall agree to assume those obligations.

         Nothing in this Section 2.5 shall limit the effect of Subsection
8.3(1) regarding consents to assignments.

2.6      Asset Purchase Price.  The Asset Purchase Price payable by the Asset
Acquiror under this Agreement for the Purchased Assets shall be the aggregate
of the respective fair market values as at the First Closing Time of the
Purchased Assets which, subject to the adjustments provided in this Article II,
shall be the aggregate of the amounts set forth in Schedule 2.6.

         The Asset Purchase Price shall be allocated amongst the Purchased
Assets in accordance with the foregoing and the Seller and the Asset Acquiror
hereby agree to report the purchase and sale of the Purchased Assets for all
Tax purposes in a manner consistent with the foregoing calculation.

2.7      Payment of Asset Purchase Price.  At the First Closing Time, the Asset
Acquiror shall pay and satisfy the Asset Purchase Price as follows:

         (a)     as to a portion of the Asset Purchase Price equal to the
                 aggregate book value of the Assumed Liabilities, by the
                 assumption by the Asset Acquiror of the Assumed Liabilities,
                 as at and from the Closing Time; and

         (b)     as to the balance of the Asset Purchase Price, by the
                 allotment, issuance and delivery to the Seller as fully paid
                 and non-assessable of 999 common shares in the capital of the
                 Asset Acquiror (the "COMMON SHARES").

         The Asset Acquiror acknowledges that the Asset Purchase Price does not
include GST payable, if any, as a result of the purchase and sale of the
Purchased Assets.





                                       17
<PAGE>   25
                                                   SIGNATURE COPY - JUNE 3, 1998


2.8      Stated Capital Account.  In accordance with the provisions of
subsection 26(3) of the Canada Business Corporations Act, the Asset Acquiror
agrees that it shall add to the stated capital account maintained by it for its
common shares in respect of the Common Shares to be issued by it pursuant to
subsection 2.7(b) an amount equal to $1.00.

2.9      Allocation of Consideration.  The aggregate consideration for the
Purchased Assets, as set out in section 2.7, shall be allocated among, and
shall be applied in payment and satisfaction of the applicable portion of the
Asset Purchase Price for each of the Purchased Assets as follows:

         (a)     the Assumed Liabilities shall be allocated:

                 (i)      firstly, to the Accounts Receivable to the extent of
                          the portion of the Asset Purchase Price (for greater
                          certainty, net of any allowance for doubtful
                          accounts) attributable thereto;

                 (ii)     secondly, to prepaid expenses and deposits included
                          in the Purchased Assets to the extent of the portion
                          of the Asset Purchase Price attributable thereto; and

                 (iii)    thirdly, to those of the Purchased Assets which
                          constitute "eligible property" (other than accounts
                          receivable) within the meaning of subsection 85(1.1)
                          of the ITA to the extent of the Elected Amount for
                          each such Purchased Asset computed in accordance with
                          Section 2.10 until the full amount of the Assumed
                          Liabilities has been allocated; and

         (b)     the Common Shares shall be allocated in payment and
         satisfaction of the balance of the Asset Purchase Price for the
         Purchased Assets.

2.10     Election under subsection 85(1) of ITA.  The Seller and the Asset
Acquiror agree to file jointly and on a timely basis an election in prescribed
form under the provisions of subsection 85(1) of the ITA in respect of the
purchase and sale of those Purchased Assets which are "eligible property" as
defined in subsection 85(1.1) of the ITA, whereby the Elected Amount in respect
of each such Purchased Asset shall be the minimum amount permissible under
section 85 of the ITA (calculated solely for this purpose on the assumption
that no portion of the Assumed Liabilities is allocated in payment of the
portion of the Asset Purchase Price attributable to such Purchased Asset) and
provided that the Elected Amount in respect of each such Purchased Asset shall
not be less than





                                       18
<PAGE>   26
                                                   SIGNATURE COPY - JUNE 3, 1998


the minimum amount of $1.00.  With respect to depreciable property and eligible
capital property as defined in the ITA, an election shall be made in respect of
each item of depreciable property and eligible capital property separately, the
order of disposition to be designated by the Seller.  The Seller and the Asset
Acquiror agree that no election under subsection 85(1) of the ITA shall be made
in respect of accounts receivable which form part of the Purchased Assets as
described in Section 1.1(nnn)(viii).  The Seller shall provide to the Asset
Acquiror upon request all available background information in its possession
which is necessary to enable the Asset Acquiror to verify the information
contained in such elections.  The Seller and the Asset Acquiror agree that the
foregoing provisions of this section shall apply, mutatis mutandis, to the
election available under the Corporations Tax Act (Ontario) and under any other
comparable legislation.

2.11     Election under section 22 of ITA.  The Seller and the Asset Acquiror
hereto agree to file such elections as are required to elect, pursuant to
subsection 22(1) of the ITA, an amount equal to the book value (net of
allowance for doubtful accounts) of the accounts receivable which form part of
the Purchased Assets as described in Section 1.1(nnn)(viii) purchased hereunder
to be the consideration paid therefor.

2.12     Election under subsection 167(1) of ETA.  The Seller and the Asset
Acquiror hereby agree to elect jointly under subsection 167(1) of the ETA, in
the prescribed form and within the prescribed time for purposes of the ETA, in
connection with the sale of the Purchased Assets hereunder.

2.13     Transfer Taxes.  The Asset Acquiror shall be liable for and shall pay
all Taxes properly payable in connection with the conveyance and transfer of
the Purchased Assets to the Asset Acquiror other than taxes calculated on or
with reference to the income or capital of the Seller (collectively, "TRANSFER
TAXES").  For greater certainty, the liability for Transfer Taxes shall not
constitute Assumed Liabilities for purposes of this Agreement and shall not
reduce the Asset Purchase Price or the Working Capital Amount.

2.14     Adjustment of Elected Amount.  In the event that Revenue Canada
disputes the Elected Amount of any of the Purchased Assets, the Seller and the
Asset Acquiror hereby agree to amend the elections referred to in Section 2.10
in accordance with the provisions of the ITA and regulations thereunder so that
the Elected Amount for such Purchased Asset shall be the amount finally
determined as such Elected Amount, whether by a court of competent jurisdiction
or by a settlement





                                       19
<PAGE>   27
                                                   SIGNATURE COPY - JUNE 3, 1998


approved by the Seller, the Asset Acquiror and Revenue Canada. In the event of
any such adjustment, the consideration allocated to the relevant Purchased
Assets shall be adjusted as of the First Closing Time so that the portion of
the Assumed Liabilities allocated as full or partial consideration for each
such Purchased Asset shall not exceed the Elected Amount.

2.15     Working Capital Statement.

         (a)     Seller shall prepare, promptly after Closing, the Working
Capital Statement prepared in accordance with the provisions of this Section
2.15.  The Working Capital Statement shall be prepared on the basis of the
accounting policies and methods used in the Financial Statements and shall show
the Working Capital Amount as of the Closing Date.

         (b)     Seller shall use commercially reasonable efforts to cause a
draft Working Capital Statement to be delivered to Asset Acquiror within 60
days after the Closing.

         (c)     Asset Acquiror shall notify Seller within 30 days of receipt
of such draft Working Capital Statement whether or not it accepts it for the
purposes of this Agreement.  In making such determination, Asset Acquiror shall
act in good faith.

         (d)     If Asset Acquiror notifies Seller that it does not accept such
draft Working Capital Statement:

                 (i)      Asset Acquiror shall set out its reasons for such
                          non-acceptance and specify the adjustments which, in
                          its opinion, should be made to the draft Working
                          Capital Statement in order to comply with the
                          requirements of this Agreement; and

                 (ii)     the Seller and the Asset Acquiror shall use all
                          reasonable efforts to meet and discuss the objections
                          of Asset Acquiror and to reach agreement upon the
                          adjustments (if any) required to be made to the draft
                          Working Capital Statement.

         (e)     If Asset Acquiror is satisfied with the draft Working Capital
Statement (either as originally submitted or after adjustments agreed upon
between Asset Acquiror and Seller) or if Asset Acquiror fails to notify Seller
of its non-acceptance of the draft Working Capital Statement within the 30 day
period referred to in Section 2.15(c), then the draft Working Capital Statement





                                       20
<PAGE>   28
                                                   SIGNATURE COPY - JUNE 3, 1998


(incorporating any agreed adjustments) shall constitute the Working Capital
Statement for the purposes of this Agreement.

         (f)     If Asset Acquiror and Seller do not reach agreement within 15
days of Asset Acquiror's notice of non- acceptance under Section 2.15(d), then
the matters in dispute shall be referred, on the request of either party, for
determination by KPMG in Toronto (or, if they are unable or unwilling to do so,
another independent firm of internationally recognized public accountants that
does not provide material services to Asset Acquiror or Seller or their
respective Affiliates) (the "FIRM").  The following provisions shall apply:

                 (i)      Asset Acquiror and Seller shall enter into an
                          engagement agreement with the Firm containing
                          customary terms and provisions, including customary
                          indemnification of the Firm;

                 (ii)     Asset Acquiror and Seller shall each promptly prepare
                          a written statement on the matters in dispute which
                          (together with the relevant documents) shall be
                          submitted to the Firm as soon as possible, and, in
                          any event, within 15 days of its appointment, for
                          determination by the Firm within 30 days of its
                          appointment;

                 (iii)    in making such determination the Firm shall state
                          what adjustments (if any) are necessary to the draft
                          Working Capital Statement in order to comply with the
                          requirements of this Agreement;

                 (iv)     Seller and Asset Acquiror shall each provide the Firm
                          with all information which it reasonably requires and
                          the Firm shall be entitled (to the extent it
                          considers appropriate) to base its opinion on such
                          information and on the accounting and other records
                          of the Seller and Asset Acquiror;

                 (v)      the Firm shall act as an expert (and not as an
                          arbitrator) in making any such determination which
                          shall (in the absence of manifest error) be final and
                          binding on the Seller and the Asset Acquiror; and

                 (vi)     the expenses of any such determination by the Firm
                          shall be shared equally by Seller and Asset Acquiror.





                                       21
<PAGE>   29
                                                   SIGNATURE COPY - JUNE 3, 1998


         (g)     Once Seller and Asset Acquiror reach (or pursuant to Section
2.15(e) are deemed to reach) agreement on the Working Capital Statement (or the
Working Capital Statement is finally determined at any stage in the procedures
set forth in this Section 2.15):

                 (i)      the Working Capital Statement as so agreed or
                          determined shall be the Working Capital Statement for
                          the purposes of this Agreement and shall be final and
                          binding on the Seller and the Asset Acquiror; and

                 (ii)     the Working Capital Amount as of the Closing shall be
                          derived from the Working Capital Statement for
                          purposes of computing the Share Purchase Price.

                                  ARTICLE III

                     PURCHASE AND SALE OF PURCHASED SHARES

3.1      Purchase and Sale of Purchased Shares.  Upon and subject to the terms
and conditions of this Agreement, the Seller shall sell, transfer, assign and
set over to the Share Acquiror and the Share Acquiror shall purchase and
acquire from the Seller at the Second Closing Time, the Purchased Shares for
the Share Purchase Price payable as provided in Section 3.3.

3.2      Share Purchase Price.  The Share Purchase Price payable by the Share
Acquiror under this Agreement for the Purchased Shares shall be, subject to the
adjustments provided in this Section 3.2 and in Section 3.6, the sum of
$41,800,000 (the "UNADJUSTED PURCHASE PRICE").  The Unadjusted Purchase Price
shall be adjusted on the Closing Date or no later than 30 days after the
Closing Date as follows:

         (a)     the Unadjusted Purchase Price shall be decreased by the amount
                 of any cash proceeds received by Seller from the sale of any
                 capital assets relating to the Aggregate Business on or after
                 January 1, 1998 and before the Closing Date; and

         (b)     the Unadjusted Purchase Price shall be increased by:

                 (i)      the amount of cash paid by the Seller on or after
                          January 1, 1998 and before the Closing Date for
                          acquisitions of aggregate businesses as going
                          concerns; and





                                       22
<PAGE>   30
                                                   SIGNATURE COPY - JUNE 3, 1998


                 (ii)     the amount of cash paid by the Seller on or after
                          January 1, 1998 and before the Closing Date in
                          respect of capital expenditures relating to the
                          Aggregate Business.

3.3      Payment of Share Purchase Price.  At the Second Closing Time, the
Share Acquiror shall pay and satisfy the Share Purchase Price for the Purchased
Shares by the allotment, issuance and delivery to the Seller, as fully paid and
non-assessable, of 100,000 redeemable, retractable preference shares in the
capital of the Share Acquiror having the rights, privileges, restrictions and
conditions set forth in the articles of incorporation of the Share Acquiror a
true copy of which is annexed as Schedule 3.3 hereto (the "PREFERENCE SHARES").

3.4      Stated Capital Account.  In accordance with subsection 26(3) of the
Canada Business Corporations, the Share Acquiror shall add to the stated
capital account maintained for its issued preference shares in respect of the
issuance of the Preference Shares pursuant to this Agreement, an amount equal
to the Elected Amount in respect of the Purchased Shares.

3.5      Election under subsection 85(1) of ITA.  The Seller and the Share
Acquiror agree to file jointly and on a timely basis an election in prescribed
form under the provisions of subsection 85(1) of the ITA in respect of the
purchase and sale of the Purchased Shares, whereby the Elected Amount shall be
an amount equal to the adjusted cost base to the Seller of the Purchased Shares
immediately before the disposition thereof pursuant to this Agreement.  In the
event that Revenue Canada disputes the Elected Amount in respect of the
Purchased Shares, the Seller and the Share Acquiror hereby agree to amend the
elections referred to in Section 3.5 in accordance with the provisions of the
ITA and regulations thereunder so that the Elected Amount for such Purchased
Shares shall be the amount finally determined as such Elected Amount, whether
by a court of competent jurisdiction or by a settlement approved by the Seller,
the Share Acquiror and Revenue Canada.

3.6      Share Purchase Price Adjustment.  The parties hereto agree that the
Unadjusted Purchase Price, as adjusted under Section 3.2, shall be adjusted
after Closing as follows such that if the Working Capital Amount as of the
Closing, as determined in accordance with Section 2.15(g) is:

                 (i)      less than the Agreed Working Capital Amount, then the
                          total price payable pursuant to Section 3.2 of this
                          Agreement shall be reduced by the amount of such
                          shortfall; or





                                       23
<PAGE>   31
                                                   SIGNATURE COPY - JUNE 3, 1998


                 (ii)     more than the Agreed Working Capital Amount, then the
                          total price payable pursuant to Section 3.2 of this
                          Agreement shall be increased by the amount of such
                          excess.

                                   ARTICLE IV

                        REDEMPTION OF PREFERENCE SHARES

4.1      Redemption of Preference Shares.  At the Third Closing Time, the Share
Acquiror shall redeem all of the Preference Shares at the Redemption Price.

4.2      Payment of Redemption Price.  The Redemption Price for the Preference
Shares shall be paid and satisfied in accordance with the redemption provisions
contained in the rights, privileges, restrictions and conditions of the
Preference Shares set forth in Schedule 3.3 hereto.

                                   ARTICLE V

           REPRESENTATIONS AND WARRANTIES OF SELLER AND LAFARGE S.A.

         As a material inducement to Asset Acquiror, Share Acquiror and Lafarge
Canada to enter into and perform their respective obligations under this
Agreement, and notwithstanding any examinations, inspections, audits, and other
investigations heretofore or hereafter made by Asset Acquiror, Share Acquiror
or Lafarge Canada, each of Seller and Lafarge S.A. hereby represents and
warrants to Share Acquiror and Lafarge Canada as follows, but subject to the
limitation that the representations and warranties in Sections 5.18 and 5.19
are qualified to the extent of any actions taken by Lafarge Canada or its
Affiliates in connection therewith on and after April 27, 1998 whether or not
the Seller knows of those actions:

         5.1     Corporate Organization and Qualification.  Each of Seller,
Lafarge S.A. and Asset Acquiror is a corporation duly organized, validly
existing and in good standing under the laws of its jurisdiction of
incorporation and Seller is, and Asset Acquiror will be at the First Closing
Time, duly qualified to do business and is in good standing in all other
jurisdictions where its ownership or leasing of property or the conduct of its
business requires it to be so qualified, and has full corporate power and
authority to own, lease and operate its properties and assets and to carry on
its business





                                       24
<PAGE>   32
                                                   SIGNATURE COPY - JUNE 3, 1998


as it is now being conducted.  Seller has heretofore made available to Asset
Acquiror, Share Acquiror and Lafarge Canada complete and correct copies of the
certificate or articles of incorporation and the bylaws of Seller and Asset
Acquiror, as currently in effect.  Asset Acquiror has not prior to the First
Closing Time carried on any business.

         5.2     Corporate Authority.  Each of Seller, Lafarge S.A. and Asset
Acquiror has full corporate power and authority to execute and deliver this
Agreement and each of the other agreements and instruments contemplated hereby
to be delivered by Seller, Lafarge S.A. and Asset Acquiror and to consummate
the transactions contemplated hereby and thereby.  The execution and delivery
of this Agreement and each other agreement and instrument contemplated hereby
to be executed and delivered by each of Seller, Lafarge S.A. and Asset Acquiror
(including, without limitation, the Non-Competition Agreements and the
Guarantee) (collectively, the "SELLER OTHER AGREEMENTS") and the consummation
of the transactions contemplated to be performed hereunder or thereunder have
been duly and validly authorized by all necessary corporate actions of each of
Seller, Lafarge S.A. and Asset Acquiror.  This Agreement has been duly and
validly executed and delivered by Seller, Lafarge S.A. and Asset Acquiror  and
constitutes, and each Seller Other Agreement will constitute when executed and
delivered to Share Acquiror and Lafarge Canada, a valid and binding agreement
of each of Seller, Lafarge S.A. and Asset Acquiror, as applicable, enforceable
against each of them respectively, as applicable, in accordance with the terms
hereof and thereof except as such enforceability may be limited by bankruptcy,
insolvency, reorganization or other similar Laws affecting the enforcement of
creditors' rights generally.

         5.3     Capital Stock.

                 (a)      The authorized capital stock of Asset Acquiror
consists of an unlimited number of  common shares, of which only the
Incorporator Share is issued and outstanding on the date of this Agreement and
only the Purchased Shares will be issued and outstanding on the Closing Date.
The Incorporator Share constitutes the only issued and outstanding capital
stock of Asset Acquiror as at the date of this Agreement.  Seller is the
registered and beneficial owner of the Incorporator Share and will become the
registered and beneficial owner of the remaining Purchased Shares at the First
Closing Time.  Neither Seller nor Lafarge S.A. is a party to, or bound by, any
agreement or understanding, other than this Agreement, restricting the voting
or transfer of the





                                       25
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                                                   SIGNATURE COPY - JUNE 3, 1998


Purchased Shares.  Upon delivery of and payment for the Purchased Shares
pursuant to this Agreement, Share Acquiror will acquire good and valid title to
the Purchased Shares, free and clear of all Liens.

                 (b)      The Incorporator Share has been and the remaining
Purchased Shares at the Second Closing Time will be duly authorized and validly
issued and are fully paid and non-assessable and free of preemptive or similar
rights.  There are no (i) securities of Seller or any other entity, or any
other instruments or rights, convertible into or exchangeable for shares of
capital stock or any other securities of Asset Acquiror, (ii) warrants, options
or other rights to acquire from Seller, or any other entity, or other
obligations of Seller or Lafarge S.A. to issue, any capital stock or other
securities or securities convertible into or exchangeable for capital stock or
any other securities of Asset Acquiror, (iii) voting trusts or agreements
relating to the capital stock of Asset Acquiror or bonds, debentures, notes or
other obligations or securities of Seller or Asset Acquiror or any other entity
the holders of which have the right to vote with the stockholders of Asset
Acquiror on any matter submitted for the vote of Asset Acquiror shareholders or
(iv) phantom security interests in, or other agreements or commitments of any
nature relating to, the capital stock or other securities of Asset Acquiror.

                 (c)      The Seller is the registered and beneficial owner of
3,750 common shares of National Slag Limited, representing 50% of the issued
and outstanding shares of National Slag Limited.

         5.4     Sufficiency of Assets.  Except to the extent that any Excluded
Assets are employed by Seller in the operation of the Aggregate Business,
including those Excluded Assets set forth in Schedule 5.4, the Purchased Assets
comprise all the property, rights and assets necessary for the carrying on of
the Aggregate Business, as and to the extent to which it is presently
conducted.  No Person, other than the Seller, has any right to the use or
possession of any material property, rights or assets (other than rights of
lessors under the Lease and the Equipment Leases that may arise in the future
following termination thereof) that are necessary for the carrying on of the
Aggregate Business.  Seller does not use in the conduct of the Aggregate
Business any material equipment, properties or assets owned by any other
Person, except property leased or licensed to Seller under the valid and
enforceable Lease and Equipment Leases.





                                       26
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                                                   SIGNATURE COPY - JUNE 3, 1998


         5.5     Conflicts and Defaults.  Neither the execution, delivery and
performance by Seller or Lafarge S.A. of this Agreement or any of the Seller
Other Agreements, nor the consummation of the transactions contemplated hereby
or thereby, nor compliance by Seller, Lafarge S.A. or Asset Acquiror with any
of the provisions hereof or thereof will, except as set forth in Schedule 5.5,
(a) violate, conflict with, or result in a breach of any provisions of, or
constitute a default which, with notice or lapse of time or both, would
constitute a default under, or result in the termination of, or accelerate the
performance required by, or result in a right of termination or acceleration
of, or result in the creation of any Lien upon any of the properties or assets
of Seller under any of the terms, conditions, or provisions of (i) its
certificates of incorporation, or by-laws, or (ii) any note, bond, mortgage,
indenture, deed of trust, license, lease, agreement, or other instrument,
obligation or arrangement to which Seller is a party or by which it may be
bound or to which Seller or any of the properties or assets of Seller may be
subject except where such violation would not have a Material Adverse Effect
and except where the consent to the transfer or assignment thereof by a Person
other than Seller is required (as described in Schedule 5.11) and such consent
is not obtained on or before the Closing Date, or (b) violate any Law
applicable to Lafarge S.A. or Seller, or any of their respective properties or
assets except where such violation would not have a Material Adverse Effect.

         5.6     Tax Returns.  Seller has provided Lafarge Canada with true
copies of its federal and provincial income tax returns for its 1994 to 1996
taxation years.

         5.7     Legal Proceedings and Governmental Compliance.

                 (a)      Except as set forth in Schedule 5.7(a) or Schedule
5.7(d), there is no pending claim, action, suit, grievance, complaint,
prosecution or other proceeding, or, to Seller's knowledge, governmental
investigation, or, to Seller's knowledge, threat of any of the foregoing,
against Seller in respect of the Aggregate Business or Purchased Assets that
involves an amount in controversy or seeks damages, penalties or fines in
excess of $50,000 or that concerns the revocation or suspension of any
Scheduled Permit, and, to the knowledge of Seller, there is no basis for any
such action.  Schedule 5.7(c) also indicates, with respect to each matter shown
thereon, whether the matter is covered (subject to applicable deductibles,
policy limits and co-insurance, if any) by insurance or not or whether there is
a reservation of rights.





                                       27
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                                                   SIGNATURE COPY - JUNE 3, 1998


                 (b)      Except as set forth in Schedule 5.7(b), to Seller's
knowledge the Aggregate Business is in compliance in all material respects with
all applicable Laws.

                 (c)      Except as set forth on Schedule 5.7(c), to Seller's
knowledge, the Licenses listed in Schedule 1.1(aaa) constitute all governmental
permits, business licenses, certificates, approvals, authorizations,
franchises, and other similar items necessary for the lawful conduct of the
Aggregate Business as it is currently conducted, including all licenses
required to comply with applicable Environmental Laws and all mining permits
and all other licenses relating to the Aggregate Business or the Purchased
Assets (collectively, the "SCHEDULED PERMITS").  Except as set forth in
Schedule 5.7(c), all Scheduled Permits are in full force and effect and are
being complied with in all material respects.  Schedule 5.7(c) also identifies
all the Licenses that are freely assignable or transferable, the Licenses that
are not assignable or transferable and the Licenses that are assignable or
transferable upon receipt of the consent of a Governmental Entity.

                 (d)      Except as set forth in Schedule 5.7(d):

                          (i)     Seller has been, and the Aggregate Business
         is being operated, in compliance in all material respects with all
         applicable Environmental Laws.

                          (ii)    There is no Environmental Claim pending or,
         to the Seller's knowledge, threatened against Seller or, to Seller's
         knowledge, pending or threatened by or against any other Person with
         respect to the Purchased Assets or the Aggregate Business or for whose
         liability for any Environmental Claim the Seller has or may have
         retained or assumed by contract or otherwise.

                          (iii)   There are no administrative or judicial
         judgments, orders or decrees that relate to violations of
         Environmental Law with respect to Seller or the Aggregate Business or
         to the release, discharge, emission or disposal of Hazardous Materials
         on, to, from or under the Purchased Properties.

                          (iv)    To Seller's knowledge, (a) there have been no
         releases, discharges, emissions or disposals of Hazardous Materials
         on, to, from or under the Purchased Properties in violation of an
         Environmental Law that have not been remediated to the satisfaction of
         the Governmental Entity with jurisdiction over said release,
         discharge, emission or disposal, and (b) no part of the Purchased
         Properties is or contains, in violation of an Environmental Law,





                                       28
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                                                   SIGNATURE COPY - JUNE 3, 1998


         a waste disposal site for non-hazardous or hazardous waste as defined
         by the Environmental Protection Act (Ontario).

As used in this Agreement, the term "ENVIRONMENTAL LAWS" means any Laws,
including written policies and guidelines and directives, administrative
rulings or interpretations, that are in effect, as well as the common law and
any judicial or administrative order, consent decree or judgment that is in
effect, and that are applicable within the Province of Ontario and which relate
to pollution or the protection of the environment, including, without
limitation, the Atomic Energy Control Act (Canada), the Canadian Environmental
Protection Act (Canada), the Pest Control Products Act (Canada), the
Transportation of Dangerous Goods Act (Canada), the Environmental Protection
Act (Ontario), the Environmental Assessment Act (Ontario), the Ontario Water
Resources Act (Ontario) and the Occupational Health & Safety Act (Ontario), and
the regulations promulgated pursuant thereto or issued by any Governmental
Entity in respect thereof, and equivalent or similar local and provincial
ordinances and statutory programs and the regulations promulgated pursuant
thereto.

         5.8     Labour and Employment.  No labour lockout, work stoppage or
organized slow down involving Seller exists or, to Seller's knowledge, is
threatened, nor has there been any such activity within the past three years.
Except for the Collective Agreements (i) no employees of the Seller are
represented by any labour union nor are any collective bargaining agreements or
negotiations otherwise in effect with respect to such employees and (ii) Seller
has no knowledge of any union organizing activities with respect to employees
of the Seller within the past three years.  Except as set forth on Schedule
5.8, there are no employment contracts with any Employees of Seller that
contain terms and conditions of employment different than those previously
disclosed by Seller to Lafarge Canada.  To Seller's knowledge, no Governmental
Entity is conducting or intends to conduct any investigation of or prosecution
regarding employment conditions or practices of Seller.  None of the Employees
is presently on temporary leave of absence, layoff or disability.

         5.9     Employee Benefit Plans.  Schedules 1.1(mm) and  5.9
collectively contain true and complete lists of all pension, retirement,
supplementary retirement, stock option, stock purchase, stock ownership,
savings, stock appreciation right, profit sharing, deferred compensation,
severance, employment, consulting, bonus, group insurance, employee welfare
and/or benefit policies, contracts, plans, and arrangements, and all trust
agreements or insurance contracts or other similar





                                       29
<PAGE>   37
                                                   SIGNATURE COPY - JUNE 3, 1998


documents relating thereto, maintained, sponsored or administered by Seller and
with respect to which Seller contributes, is obligated to contribute or has or
may have any liability, or which covers any of the present or former directors,
officers, or other employees of the Seller (collectively, "BENEFIT PLANS").
Seller has delivered to Lafarge Canada true and complete copies of each Benefit
Plan, including all amendments thereto, and true and complete copies of each of
the following documents (collectively, the "BENEFIT PLAN DOCUMENTS"):  (i) all
Benefit Plan summaries, booklets and manuals describing or giving particulars
of the plan or, where such Benefit Plan is an oral commitment, a written
summary of the terms thereof;   (ii) the two most recently completed annual
information returns and/or actuarial reports, if any, prepared in respect of
each Benefit Plan together with all of the annual information returns in the
possession of Seller for the Queenston Hourly-Rated Employees Pension Plan; and
(iii) any trust or other funding agreement or contract (including all
amendments thereto) relating to any Benefit  Plan and the latest financial
statements thereof.  Except as set forth in Schedule 5.9 all Benefit Plans
currently comply and have at all relevant times complied in all material
respects with all applicable Laws, including, without limitation, the ITA.  All
material terms and conditions of the Benefit Plans are reflected in the Benefit
Plan Documents and, without limiting the foregoing, no promises or commitments
have been made by the Seller to amend any Benefit Plan or to provide increased
benefits thereunder to any employee, except as required by Law.

                 (a)      Each of the Benefit Plans is duly registered, where
required, with all applicable regulatory authorities, and has at all relevant
times been funded and administered in all material respects in accordance with
all Laws applicable to the plan, and in accordance with the terms of the plan
and all employee plan summaries, booklets and manuals relating thereto.

                 (b)      Except as disclosed in Schedule 5.9, there are no
pending or, to Seller's knowledge, threatened or anticipated claims by or on
behalf of the Benefit Plans or by any participant therein, alleging a breach or
breaches of fiduciary duties or violations of applicable Laws which could
result in any material liability on the part of the Seller, or its officers,
directors or employees, or on the part of such Benefit Plans under any
applicable Laws and, to Seller's knowledge, there is no basis for such claim.





                                       30
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                                                   SIGNATURE COPY - JUNE 3, 1998


                 (c)      Except as disclosed in Schedule 5.9 all obligations
of Seller under the Benefit Plans with respect to the making and remittance of
contributions or premiums have been satisfied in accordance with such plan
terms.  All employee contributions to any of the Benefit Plans which have been
received by Seller or deducted by it from the remuneration of employees have
been fully paid into the funding arrangement for the respective plan.

                 (d)      Each of the Benefit Plans which is a Pension Plan is
duly registered under and has been administered in all material respects in
compliance with all applicable federal and provincial legislation and all
reports, returns and filings required to be made thereunder have been made.
All contributions required to be made by Seller to each of the Pension Plans in
order to comply with the minimum funding standards imposed by applicable
federal or provincial legislation have been made or properly accrued, and each
Pension Plan is being funded in accordance with the requirements of such plan
and the most recent actuarial report prepared in respect thereof.  No funds
have been withdrawn by Seller from any of the Pension Plans and no application
for approval of a  withdrawal of plan funds has been made to any applicable
regulatory authority.  None of the Pension Plans is a multi-employer pension
plan as defined under the provisions of any applicable federal or provincial
legislation.

                 (e)      With respect only to the Queenston Hourly Rated
Employees Pension Plan:

                          (i)     to the best of the knowledge of Seller, all
         employer contribution holidays, if any, that have been taken have been
         permitted by the terms thereof and have been in accordance with
         applicable Laws;

                          (ii)    no event has occurred and no condition or
         circumstance exists that has resulted or, to the best of the knowledge
         of the Seller could reasonably result in, any order or requirement by
         any Governmental Entity of termination or winding-up in whole or in
         part, or refusal or revocation of registration under any applicable
         Law, or placement under administration of any trustee or receiver or
         any Governmental Entity or requirement to pay any material Taxes under
         any applicable Law;

                          (iii)   no event has occurred and there has been no
         failure to act on the part of the Seller, any funding agent or any
         administrator thereof that could subject the Seller or





                                       31
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                                                   SIGNATURE COPY - JUNE 3, 1998


         the fund of the pension plan to the imposition of any Tax or
         disability, whether by way of indemnity or otherwise; and

                          (iv)    as at Closing, such Plan will not have an
         unfunded liability on either a solvency or on a going-concern basis.

         5.10    Financial Statements.  Attached hereto as Schedule 5.10 are
the Financial Statements. The Financial Statements have been prepared from the
books and records of the Seller.  The Financial Statements have been prepared
in accordance with GAAP (except for the treatment of Seller's holding of shares
in the capital stock of Redland France S.A.  and the use of "push-down" or
purchase accounting required as a result of the acquisition by Redland PLC of
Steetley Quarries Inc.) on a consistent basis and fairly present, in all
material respects, the financial position and results of operations of Seller
as of the date and for the periods indicated therein.

         5.11    Consents.  No filing with, and no consent, licence, permit or
franchise from any Governmental Entity or any other Person is necessary or
required to be received in connection with the consummation by Seller and Asset
Acquiror of the transactions contemplated by this Agreement and the Seller
Other Agreements other than as set forth in Schedule 5.11 or Schedule 5.7(c).

         5.12    Ownership of Assets.

                 (a)      Seller has, as of the date hereof, and on the Closing
Date Seller and Asset Acquiror will have, good and indefeasible title to the
Purchased Assets free and clear of all Liens other than (i) materialman's and
mechanics Liens and other Liens arising as a matter of Law which are listed in
Schedule 5.12(a), (ii) purchase money security interests which are listed in
Schedule 5.12(a) and (iii) such other Liens, defects and other encumbrances as
do not (individually or in the aggregate) materially affect the use or value of
the Purchased Assets or materially interfere with the conduct of the Aggregate
Business as now conducted (collectively, the "PERMITTED LIENS").  All Equipment
Leases are valid and binding leases.

                 (b)      Other than the market value re-assessment imposed in
1997 in relation to the Real Property, to Seller's knowledge there are no plans
of any Governmental Entity which would result in the imposition of a special
assessment relating to any of the Real Properties that is not reserved in the
Financial Statements and that is in excess of $20,000.





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                                                   SIGNATURE COPY - JUNE 3, 1998


         5.13    Material Adverse Change.  To Seller's knowledge, since
December 31, 1997 the Seller has, except as contemplated by this Agreement,
conducted its Aggregate Business in the ordinary course of business consistent
with past practice.  Except as set forth in Schedule 5.13, since December 31,
1997 Seller has not  (i) transferred, leased or otherwise disposed of any of
its assets or properties relating to the Aggregate Business, other than in the
ordinary course of business consistent with past practice; (ii) in respect of
the Aggregate Business or the Purchased Assets, suffered any material casualty
loss or damage (whether or not such loss or damage shall have been covered by
insurance) or received any claim or claims in excess of insurable limits, or
canceled any insurance coverage; (iii) other than in the ordinary course of
business, surrendered, revoked or otherwise terminated or had terminated any
material license, permit, registration or other approval, authorization or
consent from any Governmental Entity or any other Person relating to the
conduct of the Aggregate Business; or (iv) entered into any agreement or
arrangement to take any action described in clauses (i) - (iii) of this Section
5.13.  Except as expressly contemplated by this Agreement or as set forth on
Schedule 7.1 or Schedule 5.13, since December 31, 1997 there has been no
Material Adverse Effect.

         5.14    Reserves.  To Seller's knowledge, the aggregate reserve
estimates for the Aggregate Business contained in Schedule 5.14 to this
Agreement fairly and accurately describe such reserves; provided, however, that
this representation shall not apply to any matter known to Lafarge Corporation
or Lafarge Canada as of the Closing.

         5.15    Contracts.

                 (a)      Schedule 5.15 sets forth a true and complete list of
(i) each agreement to which Seller is a party that would be reasonably expected
to materially limit the freedom of Asset Acquiror to continue the Aggregate
Business or compete with any Person or in any geographical area or otherwise to
conduct the Aggregate Business as currently conducted; (ii) each contract or
agreement for maintenance, consulting, engineering or other services relating
to the Aggregate Business or the Purchased Assets which requires the remaining
payment of money by Seller in excess of $50,000; (iii) each sales contract or
agreement with a customer of the Aggregate Business which provides for
remaining payment in excess of $50,000 to Seller for products produced pursuant
to which any customer would be expected to pay in excess of $50,000 to Seller
for such products





                                       33
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                                                   SIGNATURE COPY - JUNE 3, 1998


during the term of such contract or agreement; (iv) each raw material purchase
contract or agreement pursuant to which raw materials were or would be
purchased for use by Seller in connection with the Aggregate Business which
provides for remaining payments in excess of $50,000; (v) each agreement or
commitment with any current or former shareholder, director, officer, employee,
or Affiliate of any such Person concerning the Aggregate Business other than
agreements or commitments which are not material to the business of the Seller
or that can be terminated without penalty on notice of six months or less; (vi)
each agreement with any Governmental Entity concerning the Aggregate Business
or any Purchased Asset, other than agreements executed in the ordinary course
of business of the Seller, agreements for the sale or provision of goods or
services and agreements otherwise referred to in clauses (i) through (v) of
this Section 5.15(a) (subject to the limitations therein); (vii) each agreement
relating to the release, or disposal of Hazardous Materials relating to the
Aggregate Business or the Purchased Assets other than customary agreements
executed in the ordinary course of business of the Seller; (viii) each
Equipment Lease; and (ix) each other agreement relating to the Aggregate
Business or the Purchased Assets which is material to the Aggregate Business.
With respect to each contract or agreement described in Section 5.15, Schedule
5.15 indicates whether such contract or agreement is freely assignable or
transferable or whether it is not freely assignable or transferable or whether
it is assignable or transferable subject to receipt of the consent of the other
party or parties to such contract or agreement.  Except with respect to the
Lease the Seller is not a tenant under any lease of real property.

                 (b)      Each agreement required to be listed on Schedule 5.15
is in full force and effect, and constitutes the legal, valid and binding
obligation of Seller and, to the knowledge of Seller, each other party thereto,
in accordance with the terms of such agreement, except that the enforceability
thereof may be limited by (i) applicable bankruptcy, insolvency,
reorganization, moratorium and similar Laws affecting creditors' rights
generally and (ii) equitable principles that may limit the availability of
certain equitable remedies (such as specific performance) in certain instances;
and, to the knowledge of Seller, there exists no material default, event,
occurrence or act, that with the giving of notice or the lapse of time would
result in a material default thereunder by Seller, as a party thereto.





                                       34
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                                                   SIGNATURE COPY - JUNE 3, 1998


         5.16    Disclosed Liabilities.  Seller does not have any liabilities
relating to the Aggregate Business (whether absolute, contingent, accrued or
otherwise), except for Excluded Liabilities, if any, relating to the Aggregate
Business and except for those (i) debts, liabilities and obligations reflected
in the Financial Statements, (ii) debts, liabilities and obligations disclosed
in Schedule 5.16 and Schedule 1.1(ff)(x), (iii) debts, liabilities and
obligations otherwise disclosed, described or referred to in Sections
7.17(d),(e) and(f) and 7.20(a) and (b)(x) as being liabilities and obligations
to be assumed by Asset Acquiror and/or Lafarge Canada in accordance with their
respective terms , and (iv) debts, liabilities or obligations incurred since
December 31, 1997 in the ordinary and usual course of the Aggregate Business
consistent with past practice (the debts, liabilities and obligations relating
to the Aggregate Business described in Sections 5.16(i), (ii), (iii) and (iv)
are referred to in this Agreement collectively as, the "DISCLOSED LIABILITIES",
and for greater certainty do not include the Excluded Liabilities); provided,
however, that if the specific factual matter relating to a Liability giving
rise to a claim under this Section 5.16 is also the subject of one or more
express representations or warranties contained in this Agreement, then the
qualification as to knowledge of the Seller, if any, or to a dollar amount, if
any, contained in such express representation and warranty shall also apply to
a claim under this Section 5.16.

         5.17    Inventory.  Each item of the Inventories is reflected in the
Financial Statements or in the books and records of Seller on the basis of
accounting procedures and valuation methods used on a basis consistent with
past practice.

         5.18    Accounts Receivable.  Except as set forth on Schedule 5.18,
the accounts receivable forming part of the Purchased Assets (the "ACCOUNTS
RECEIVABLE") are in respect of sales actually made, services actually delivered
or transactions actually completed by the Seller in bona fide transactions in
the ordinary course of business consistent with past practice.  Except as set
forth on Schedule 5.18, none of the Accounts Receivable represents accounts
receivable from any of the Affiliates of Seller.  All Accounts Receivable
arising on or before December 31, 1997 are good and collectable.





                                       35
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                                                   SIGNATURE COPY - JUNE 3, 1998


         5.19    Affiliate Transactions.  With respect to the Aggregate
Business, Schedule 5.19 discloses the dollar amount and a brief description of
each transaction and the date thereof between the Seller, on the one hand, and
any Affiliate of Seller, on the other hand, between December 31, 1996 and the
date of this Agreement (the "AFFILIATE TRANSACTIONS").

         5.20    Customers and Suppliers.  Schedule 5.20 contains a true and
complete list of the names and addresses of the 50 largest suppliers and
customers during 1997 of Seller relating to the Aggregate Business.  As at
December 31, 1997, the Seller had not received notice of, and to Seller's
knowledge, there was no reasonable basis for, any development which threatened
to affect adversely any arrangements with the customers and suppliers listed on
Schedule 5.20.

         5.21    Insurance.  Seller maintains, and has heretofore maintained,
and there are currently in full force and effect, policies of insurance that
are, in combination with Seller's self insurance, reasonable for the conduct of
the Aggregate Business as currently and heretofore conducted.

         5.22    Intellectual Property.  To Seller's knowledge, Seller has not
violated or infringed any patents, trademarks, trade names, assumed names,
copyright and other similar intangible property rights and interests applied
for, issued to or presently owned or used by any Person or under which any such
Person is licensed or franchised or any license, authorization or permit
relating to the Intellectual Property Rights.  To Seller's knowledge, there are
no proceedings pending or threatened, alleging that the conduct of the
Aggregate Business infringes upon or constitutes the unauthorized use of the
proprietary rights of any third party other than such violations or
infringements which, individually or collectively, would not have a Material
Adverse Effect.

         5.23    Condition of Assets.  EXCEPT AS EXPRESSLY SET FORTH HEREIN,
NEITHER SELLER NOR LAFARGE S.A. MAKES ANY REPRESENTATION OR WARRANTY (EXPRESS
OR IMPLIED) AS TO THE CONDITION, REPAIR, QUANTITIES, SALABILITY,
MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OF ANY OF THE PURCHASED
ASSETS AND, EXCEPT AS EXPRESSLY SET FORTH HEREIN, LAFARGE CANADA, ASSET
ACQUIROR AND SHARE ACQUIROR ACCEPTS SUCH ASSETS "AS IS, WHERE IS."

         5.24    Purchased Assets.  The Purchased Assets referred to in any
Schedule to this Agreement are accurately described.





                                       36
<PAGE>   44
                                                   SIGNATURE COPY - JUNE 3, 1998


         5.25    Location of Assets.  All material tangible assets of the
Seller used in or in connection with the Aggregate Business are all normally
situate only in the Province of Ontario; the location at which such assets are
normally situate is set forth in Schedule 5.25.

         5.26    Real Property.  The Purchased Properties and their existing
and prior uses comply with, and at all material times have complied with, and
the Seller is not in violation of or has not violated in connection with the
ownership, use, maintenance or operation of the Purchased Properties, any
applicable Laws.  There are no currently outstanding work orders or directions
requiring any work, repairs, construction or capital expenditures with respect
to the Purchased Properties and no such orders or directions are pending or
threatened.  All physical plant and operations of the Aggregate Business and
the Lime Business that are located at or carried on from Dundas Site and
Queenston Site are located at or carried on from within the legal boundaries of
the Purchased Properties.  The Seller is not aware of any encroachments,
easements or rights of way affecting the Purchased Properties except as
disclosed in Schedules 1.1(ooo)(i), (ii), (iii) and (iv) hereof.

         5.27    Guarantees and Indebtedness.  Except as disclosed in Schedule
5.27, the Seller is not a party to or bound by any guarantee, indemnification,
surety or similar obligation (except for product warranties and guarantees
granted in the ordinary course of business ) in respect of the Aggregate
Business.

         5.28    Material Contracts.  Except for the Contracts, the Equipment
Leases, the Lease and agreements with the Seller's bank concerning a Cdn.
$1,000,000 overdraft credit facility and Seller's acceptance of payments by
VISA credit card, the Seller is not a party to or bound by any material
contract or commitment relating to the Aggregate Business whether oral or
written.

         5.29    No Options.  No Person other than the Asset Acquiror has any
agreement or option or any right capable of becoming an agreement or option for
the purchase from the Seller of any of the Purchased Assets, other than
purchase orders accepted by the Seller in the ordinary course of business.

         5.30    Expropriation.  No part of the Purchased Assets has been taken
or expropriated by any Governmental Entity nor has any notice or proceeding in
respect thereof been given or





                                       37
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                                                   SIGNATURE COPY - JUNE 3, 1998


commenced nor is the Seller aware of any intent or proposal to give such notice
or commence any such proceedings.

         5.31    Residence.  The Seller is not a non-resident of Canada for
purposes of section 116 of the ITA.

         5.32    GST Registration.  The Seller is a registrant for purposes of
GST and Seller's GST registration number is R136027851.

         5.33    Tax Matters.  Seller is not in arrears or in default in
respect of the filing of any Tax or other return; and,

                 (i)      all Taxes due and payable have been paid to the
                          appropriate Governmental Entity and all Taxes
                          required to be remitted have been remitted in the
                          ordinary course and, to the extent required, have
                          been remitted to the appropriate Governmental Entity;

                 (ii)     no claim for additional Taxes, filing fees, or other
                          amounts and assessments has been made that has not
                          been paid;

                 (iii)    to the best of the Seller's knowledge, no such return
                          contains any misstatement or conceals any statement
                          that should have been included therein; and

                 (iv)     the Purchased Assets have not previously been
                          transferred on a tax-exempt basis under section 13 of
                          Ontario Regulation 1013 or any predecessor thereof.

         5.34    Worker's Compensation.  All levies under the Workplace Safety
and Insurance Act, 1997 (Ontario) have been paid by the Seller.

         5.35    Health and Safety.  The business premises located on the
Purchased Properties are in compliance with applicable Laws relating to
sanitation and health and safety and are not subject to any orders or
directions of a sanitation or occupational health and safety authority or
similar body including the Ontario Ministry of Labor, nor is the Seller subject
to any prosecution for any alleged violation of any such legislation or
regulations in respect of the said business premises, or any act or omission
which occurred on or in connection with the said business premises.

         5.36    Consents.  Except for Contracts and Equipment Leases requiring
the consent to assignment of third parties as provided in Schedule 5.15 and
with respect to the Licenses as provided





                                       38
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                                                   SIGNATURE COPY - JUNE 3, 1998


in Schedule 5.7(c), there are no consents, authorizations, approvals or orders
of any Person or Governmental Entity required in connection with the conveyance
by the Seller to the Asset Acquiror of the Purchased Assets.

                                   ARTICLE VI

                    REPRESENTATIONS AND WARRANTIES OF SHARE
                          ACQUIROR AND LAFARGE CANADA

         As a material inducement to Seller and Lafarge S.A. to enter into and
perform their respective obligations under this Agreement, and notwithstanding
any examinations, inspections, audits, and other investigations heretofore or
hereafter made by Seller or Lafarge S.A., Share Acquiror and Lafarge Canada
hereby represent and warrant to Seller and Lafarge S.A. as follows:

         6.1     Corporate Organization and Qualification.  Each of Share
Acquiror and Lafarge Canada is a body corporate duly organized, validly
existing and in good standing under the laws of its jurisdiction of
incorporation.

         6.2     Corporate Authority.  Each of Share Acquiror and Lafarge
Canada has the requisite corporate power and authority to execute and deliver
this Agreement and to consummate the transactions contemplated hereby.  Except
for any shareholder approvals (or an exemption therefrom) required under
applicable Law, the execution and delivery of this Agreement and each other
agreement and instrument contemplated hereby to be executed and delivered by
each of Share Acquiror and Lafarge Canada (collectively, the "ACQUIROR OTHER
AGREEMENTS") and the consummation by them of the transactions contemplated to
be performed hereunder or thereunder have been duly authorized by all necessary
corporate actions of Share Acquiror and Lafarge Canada. This Agreement and the
Acquiror Other Agreements to which they are a party are each valid and binding
obligations of Share Acquiror and Lafarge Canada, enforceable against them
respectively in accordance with the terms hereof or thereof except as such
enforceability may be limited by bankruptcy, insolvency, reorganization or
other similar Laws affecting the enforcement of creditors' rights generally.

         6.3     Conflicts and Defaults.  Neither the execution, delivery and
performance by Share Acquiror or Lafarge Canada of this Agreement or any of the
Acquiror Other  Agreements, nor the





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                                                   SIGNATURE COPY - JUNE 3, 1998


performance by Share Acquiror or Lafarge Canada of the transactions
contemplated hereby or thereby, nor compliance by Share Acquiror or Lafarge
Canada with any of the provisions hereof of thereof will, except as set forth
in Schedule 6.3: (a) violate, conflict with, or result in a breach of any
provisions of, or constitute a default which, with notice or lapse of time or
both, would constitute a default under, or result in termination of, or
accelerate the performance required by, or result in a right of termination or
acceleration of, any of the terms, conditions or provisions of (i) its articles
of incorporation or bylaws, or (ii) any note, bond, mortgage, indenture, deed
of trust, license, lease, agreement, or other instrument, obligation or
arrangement to which Share Acquiror or Lafarge Canada is a party or by which
they may be bound, or to which Share Acquiror or Lafarge Canada or any of their
respective properties or assets may be subject, except where such violation
would not have a material adverse effect on the Share Acquiror or Lafarge
Canada or (b) violate any judgment, ruling, order, writ, injunction, decree,
statute, rule or regulation applicable to Share Acquiror or Lafarge Canada or
any of their respective properties or assets except where such violation would
not have a material adverse effect on the Share Acquiror or Lafarge Canada.

         6.4     Consents and Approvals.  Except for any shareholder approvals
(or an exemption therefrom) required under applicable Law, no consent,
approval, order or authorization of, or registration, declaration or filing
with, any Governmental Entity or Person is required with respect to Share
Acquiror or Lafarge Canada in connection with the execution,  delivery or
performance by Share Acquiror or Lafarge Canada of their respective obligations
under this Agreement or the Acquiror Other Agreements except for consents,
approvals, orders, authorizations, registrations, declarations or filings the
failure of which to obtain or to make would not have, individually or in the
aggregate, a material adverse effect on Share Acquiror's or Lafarge Canada's
ability to consummate the transactions contemplated by this Agreement.

         6.5     GST Registration.  The Asset Acquiror is a registrant for
purposes of GST and Asset Acquiror's GST registration number is R868904590.

         6.6     Funds for the Acquisition.  Share Acquiror will, as of the
Closing Date, have sufficient unencumbered funds to pay in cash the Unadjusted
Purchase Price and all of its fees and expenses relating to this Agreement and
the transactions contemplated hereby.





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                                                   SIGNATURE COPY - JUNE 3, 1998


                                  ARTICLE VII

                        CERTAIN COVENANTS OF THE PARTIES

7.1      Conduct of the Seller and Lafarge S.A. During the period from the date
of this Agreement and continuing until the First Closing Time, Seller and
Lafarge S.A. shall, except as otherwise contemplated by this Agreement or as
described on Schedule 7.1, in all material respects, conduct the Aggregate
Business and the Lime Business in the ordinary course thereof consistent with
past and current practices, and, Seller and Lafarge S.A. shall use their
reasonable best efforts to maintain and preserve the business organization of
the Aggregate Business and the Purchased Assets and the Employees and business
relationships thereof and to retain the services of the officers and key
Employees thereof.

7.2      Forbearances by Seller.  Except as expressly contemplated by this
Agreement, without the prior written consent of Lafarge Canada, during the
period from the date of this Agreement to the Closing Date, Seller shall not:

                 (a)      sell, lease, transfer, assign or otherwise dispose of
any real property or any other material assets of the Aggregate Business, other
than sales of personal property in the ordinary course of business of the
Seller;

                 (b)      make any capital expenditure or commitment for
capital expenditures in connection with the Aggregate Business in excess of
$50,000;

                 (c)      create, incur, guarantee or assume any obligation or
liabilities in connection with the Aggregate Business, except to the extent
created, incurred, guaranteed or assumed in the ordinary course of business and
consistent with past practice;

                 (d)      discharge or satisfy any encumbrance or liability in
connection with the Aggregate Business (whether absolute, accrued, contingent
or otherwise and whether due or to become due), other than encumbrances or
current liabilities incurred in the ordinary course of business and consistent
with past practice, and discharged or satisfied in the ordinary course of
business and consistent will past practice;

                 (e)      permit or allow any of the Purchased Assets to be
mortgaged, pledged or subjected to any Lien, except Permitted Liens;





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                                                   SIGNATURE COPY - JUNE 3, 1998


                 (f)      enter into or amend any employment, severance, or
similar agreements or arrangements with any director, officer, key employee or
consultant in respect of the Aggregate Business;

                 (g)      cancel, release or assign any indebtedness owed or
rights of claims held by Seller in respect of the Aggregate Business that is
individually in excess of $20,000;

                 (h)      propose or adopt any amendments to the certificates
or articles of incorporation, or by-laws of the Asset Acquiror;

                 (i)      issue any shares of capital stock or other securities
or effect any stock split or otherwise change the capitalization of the Asset
Acquiror as it existed as of the date hereof;

                 (j)      grant, confer or award any options, warrants,
conversion rights or other rights not existing on the date hereof to acquire
any shares of the capital stock of the Asset Acquiror;

                 (k)      amend or cancel or default under any of the contracts
required to be set forth in Schedule 5.15 other than amendments and
cancellations in the ordinary course of business that would not reasonably be
expected to result in a Material Adverse Effect;

                 (l)      purchase or redeem any shares in the capital stock of
the Asset Acquiror;

                 (m)      other than in the ordinary course of business of the
Seller, take any actions, or fail to take any actions which alone, or together
with any other action or inaction, shall create, alter or eliminate any rights,
benefits, obligations or liabilities of any Person (including, but not limited
to the participants, or beneficiaries) with respect to any Benefit Plans to the
extent that they relate to the Aggregate Business; or

                 (n)      agree in writing or otherwise to take any of the
foregoing actions or engage in any activity or enter into any transaction with
respect thereto.

7.3      Access and Information.  Between the date hereof and the Closing Date,
Lafarge S.A. and Seller shall afford to Share Acquiror and Lafarge Canada and
their officers, employees, accountants, counsel and other authorized
representatives full and complete access during normal business hours to their
respective officers, employees, accountants, counsel, properties, facilities,
contracts (including true and complete copies of contracts required to be
listed in Schedule 5.15), commitments, books and records (including, but not
limited to, Tax returns) and any material report, schedule or other document
filed or received by them during such period pursuant to the





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                                                   SIGNATURE COPY - JUNE 3, 1998


requirements of Laws and shall cause their respective representatives to
furnish promptly such additional financial and operating data and other
information relating to the Aggregate Business and Purchased Assets as Share
Acquiror, Lafarge Canada or their duly authorized representatives may from time
to time reasonably request.  All information obtained by Share Acquiror and
Lafarge Canada under this Section shall be subject to the Confidentiality
Agreement heretofore entered into by or on behalf of Lafarge Corporation and
Lafarge S.A. which agreement may be shown to any Person.

7.4      Current Information.  During the period from the date of this
Agreement to the Closing Date, Seller and Lafarge S.A. shall cause one or more
of their designated representatives to confer on a regular and frequent basis
with representatives of Share Acquiror and Lafarge Canada.  Seller or  Lafarge
S.A. shall promptly notify Share Acquiror and Lafarge Canada of any material
change known to Seller or Lafarge S.A. in the Aggregate Business or operations
including, without limitation, the loss or destruction of any material asset
and of any material governmental complaints, investigations, or hearings or the
institution of material litigation or administrative or other claim involving
Seller, and shall keep Share Acquiror and Lafarge Canada fully informed of such
events.

7.5      Satisfaction of Conditions.

                 (a)      Each Party to this Agreement shall use reasonable
efforts to satisfy promptly all conditions precedent to the obligations of the
other Parties to consummate the transactions contemplated by this Agreement.

                 (b)      In addition to the obligations set forth in Section
7.5(a), Lafarge Canada, at its expense, will timely and promptly make all
filings and obtain any approvals which are required under the Investment Canada
Act (Canada).  Seller will furnish to Lafarge Canada such necessary information
and reasonable assistance as Lafarge Canada may reasonably request in
connection with the preparation of necessary filings or submissions to any
Governmental Entity including, without limitation, any filings or approvals
required under the Investment Canada Act (Canada).  Lafarge Canada will supply
Seller with copies of all correspondence, filings or communications (or
memoranda setting forth the substance thereof) between Lafarge Canada or any of
its respective representatives, on the one hand, and the Minister of Industry
appointed under the Investment Canada Act (Canada) or any member of its staff,
on the other hand, with respect to the filings or





                                       43
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                                                   SIGNATURE COPY - JUNE 3, 1998


approvals to be made under the Investment Canada Act (Canada) with respect to
this Agreement or the transactions contemplated hereby.

                 (c)      Seller and Lafarge S.A. shall use their reasonable
best efforts and pay all expenses (other than in respect of filings or
approvals to be made under the Investment Canada Act (Canada) and any
shareholder approvals) necessary to obtain any licenses, permits, consents,
approvals, authorizations,  qualifications and orders of Governmental Entities
and parties to contracts as are required in connection with the consummation of
the transactions contemplated hereby.  Subject to the terms and conditions
hereof, each of the parties hereto agrees to use its reasonable best efforts to
take, or cause to be taken, all actions and to do, or cause to be done, all
other things necessary, proper or advisable to consummate and make effective
the transactions contemplated by this Agreement and the Seller Other Agreements
and the Acquiror Other Agreements as soon as practicable. The parties hereto
shall cooperate in the defense of any lawsuits or other legal proceedings,
whether judicial or administrative, whether brought derivatively or on behalf
of third parties (including governmental agencies or officials), challenging
this Agreement or the consummation of the transactions contemplated hereby.

7.6      Public Announcements.  Except as may be required by applicable Laws,
the Rules of the New York Stock Exchange, the Societe des Bourses Francaises,
the London Stock Exchange, The Toronto Stock Exchange, the Montreal Exchange or
a Governmental Entity or as agreed by the parties hereto, none of Asset
Acquiror, Share Acquiror, Seller, Lafarge S.A. or Lafarge Corporation will
issue any press release or make any public statement relating to the
transactions contemplated by this Agreement prior to the Closing Date; provided
that after the Closing Date or with respect to public statements as may be
required by applicable Laws, the Rules of the New York Stock Exchange, the
Societe des Bourses Francaises, the London Stock Exchange, The Toronto Stock
Exchange, the Montreal Exchange or a Governmental Entity, Asset Acquiror, Share
Acquiror, Seller, Lafarge S.A. and Lafarge Corporation will consult with each
other prior to the issuance of any such press release or making of any such
public statement as to the content of any such press release or public
statement.

7.7      Further Assurances.  From and after the Closing, the Parties shall
execute and deliver, in the name and on behalf of the Parties, as appropriate,
any assignments or assurances and take and do,





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                                                   SIGNATURE COPY - JUNE 3, 1998


in the name and on behalf of the Parties, as appropriate, any other actions and
things reasonably necessary to carry out the intention of this Agreement.

7.8      Notice of Breaches.  Seller will promptly, and in any event prior to
the Closing, notify Share Acquiror and Lafarge Canada in writing if Seller
becomes aware prior to the Closing that any representation or warranty made by
Seller in this Agreement is inaccurate or untrue in any material respect,
whether or not the cause thereof relates to any actions taken by Lafarge Canada
or its Affiliates in connection with the management or conducting of the
Aggregate Business on or after April 27, 1998.  Said notice shall set forth the
facts and circumstances causing such inaccuracy or untruth.  Except if caused
by any actions taken by Lafarge Canada or its Affiliates in connection with the
management or conducting of the Aggregate Business on or after April 27, 1998,
Lafarge S.A. and Seller each expressly acknowledge and agree that Share
Acquiror's and Lafarge Canada's actual or constructive knowledge of any
inaccuracy or untruth in any representation or warranty prior to Closing shall
not be deemed to have cured or otherwise excused any breach of such
representation or warranty that otherwise might have existed by reason of such
inaccuracy or untruth or otherwise waive any right Share Acquiror and Lafarge
Canada may have with respect to such representation or warranty.

7.9      Access to Books, Records and Personnel.  Following the Closing, Asset
Acquiror and Lafarge Canada shall, upon Seller's reasonable written request and
at Seller's expense, fully cooperate with Seller and afford to Seller and its
counsel, accountants and other authorized representatives reasonable access
during normal business hours to all books, records, data, facilities,
properties and personnel relating to the Aggregate Business or the Purchased
Assets (and permit Seller and its counsel, accountants and other authorized
representatives to make copies of such books, records and other data), to the
extent that such access may be reasonably requested by Seller: (i) to
facilitate the investigation, litigation or final disposition of any claim
which may have been or may be made by or against Seller or any of its
Affiliates in connection with this Agreement or the transactions contemplated
hereby or with respect to the Aggregate Business or the Purchased Assets
relating to the period before the Closing Date, (ii) to facilitate the
preparation by Seller of materials necessary for any audit, examination or
proceeding or (iii) to facilitate the preparation and the audit of the Working
Capital Statement.





                                       45
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                                                   SIGNATURE COPY - JUNE 3, 1998


7.10     Delivery of Books and Records.  At the Time of Closing, the Seller
shall deliver to the Asset Acquiror and Lafarge Canada the following documents:
(i) lists of suppliers and customers of the Seller which relate to the
Aggregate Business;  (ii) employee records with respect to employees of Seller
hired by Asset Acquiror;  (iii) advertising, promotional and marketing
materials which relate to the Aggregate Business; and (iv) files relating to
the Aggregate Business and the Purchased Assets including, without limitation,
the maintenance records for each item of equipment or machinery included in the
Purchased Assets.  The Asset Acquiror and Lafarge Canada agree that they will
preserve all documents, data, books and records so delivered to it for a period
of six years from the Closing Date, or for such other period as is required by
any applicable Laws. The Seller agrees that it will preserve for a period of
six years from the Closing Date, or for such longer period as is required by
applicable Laws, all documents, data, books and records which relate in whole
or in part to the Aggregate Business and which are not delivered to the Asset
Acquiror and Lafarge Canada, and Seller will, upon the reasonable written
request of Asset Acquiror or Lafarge Canada and at their expense, fully
co-operate with and permit the Asset Acquiror and Lafarge Canada and their
counsel, accountants and other authorized representatives reasonable access
during normal business hours to those documents, data, books and records in
connection with the affairs of the Asset Acquiror and Lafarge Canada relating
to the Aggregate Business (and permit Share Acquiror and Lafarge Canada and
their counsel, accountants and other authorized representatives to make copies
of such documents, books, records and other data).

7.11     Lafarge S.A. Guarantee.  Lafarge S.A. hereby agrees to execute and
deliver to Asset Acquiror and Lafarge Canada at Closing, a Guarantee, in
substantially the form and content attached as Schedule 8.3(e) (the
"GUARANTEE").

7.12     Deleted.

7.13     Bulk Sales.  The Asset Acquiror and Lafarge Canada hereby waive
compliance with the provisions of the Bulk Sales Act (Ontario) or any other
applicable bulk sales legislation in respect of the purchase and sale of the
Purchased Assets and the Seller hereby agrees to indemnify and save harmless
the Asset Acquiror and Lafarge Canada from and against all losses suffered or
incurred by Asset Acquiror as a result of such non-compliance.





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                                                   SIGNATURE COPY - JUNE 3, 1998


7.14     Removal of Purchased Assets.  The Seller shall permit access by the
Asset Acquiror following Closing to those locations not leased or transferred
to the Asset Acquiror to enable the Asset Acquiror to remove Purchased Assets
from such locations.

7.15     Retail Sales Tax.  The Seller agrees to use its commercially
reasonable efforts to deliver to the Asset Acquiror after the Closing Date a
clearance certificate under section 6 of the Retail Sales Tax Act (Ontario).

7.16     Consents Required in Contracts.  The Seller shall be responsible for
managing the process of obtaining any consent to assignment which may be
required for the assignment of any Licence, Contract or Equipment Lease which
are included in the Purchased Assets as a result of the consummation of
transactions contemplated by this Agreement.  Lafarge Canada shall actively
assist and co-operate with Seller in seeking to obtain the necessary consents
to assignment, or, to the extent that any Licence is not by Law or by its terms
assignable, Lafarge Canada shall actively apply for and seek the issue of a
replacement Licence.  If the Seller is unable to obtain such consent, such
Licence, Contract or Equipment Lease shall not be assigned and the Seller
shall, to the extent legally possible, hold its right, title and interest in,
to and under such Licence, Contract or Equipment Lease in trust for the benefit
of the Asset Acquiror until such consent is obtained in accordance with Section
2.5 of this Agreement.

7.17     Employees

         (a)     EMPLOYMENT BY ASSET ACQUIROR- The Asset Acquiror or Lafarge
                 Canada shall, effective from the First Closing Time,

                 (i)      offer employment to all of the Seller's salaried
                          employees who are identified in Schedule 7.17 under
                          the heading "Salaried Staff @ May 1, 1998" or who
                          become, subject to Section 7.2(f), salaried employees
                          of the Seller working in the  Aggregate Business on
                          or before the First Closing Time (collectively, the
                          "SALARIED EMPLOYEES"); and

                 (ii)     employ all of the Seller's hourly employees, the
                          terms of employment of whom are governed under a
                          Collective Agreement, who are identified in Schedule
                          7.17 under the heading "Hourly Staff @ May 1, 1998"
                          or who become hourly employees of the Seller working
                          in the Aggregate Business





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                                                   SIGNATURE COPY - JUNE 3, 1998


                          on or before the First Closing Time or who may
                          exercise, on or at any time after the First Closing
                          Time, any right they may have under a Collective
                          Agreement to claim a job with Asset Acquiror or
                          Lafarge Canada in connection with any Purchased Asset
                          (collectively, the "HOURLY EMPLOYEES").

                 The Salaried Employees and the Hourly Employees are referred
                 to collectively in this Agreement as, the "EMPLOYEES".   Asset
                 Acquiror or Lafarge Canada, as the case may be, shall offer to
                 employ the Salaried Employees on terms and conditions of
                 employment which are the same as the terms and conditions of
                 employment, including salary, incentive compensation,
                 benefits, provided by Lafarge Canada to its employees with
                 substantially identical employment status.  Nothing in this
                 Agreement shall confer on any Employee the right to continue
                 in the employ of the Asset Acquiror or Lafarge Canada or
                 interfere with or restrict in any way the rights of Asset
                 Acquiror or Lafarge Canada to discharge any Employee who
                 becomes employed by Asset Acquiror or Lafarge Canada at any
                 time for any reason, with or without cause.  The Asset
                 Acquiror and Lafarge Canada, as the case may be, shall
                 recognize the service of the Employees with the Seller or its
                 predecessors up to the First Closing Time for all purposes as
                 if such service had occurred with the Asset Acquiror and/or
                 Lafarge Canada.  The Seller will cooperate with the Asset
                 Acquiror and Lafarge Canada in giving notice to the Employees
                 of the matters referred to in this Section 7.17 as is
                 considered necessary and reasonable in the circumstances by
                 the Asset Acquiror and Lafarge Canada.

         (b)     COLLECTIVE AGREEMENTS - The Asset Acquiror and Lafarge Canada
                 acknowledge and agree that they will be a successor to the
                 Seller to the Collective Agreements applicable to the Hourly
                 Employees pursuant to the provisions of the Labour Relations
                 Act (Ontario) as of the First Closing Time and will be bound
                 by the provisions of the Collective Agreements, as amended or
                 supplemented from time to time, as they apply to the Hourly
                 Employees.





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<PAGE>   56
                                                   SIGNATURE COPY - JUNE 3, 1998


         (c)     REMUNERATION AND BENEFITS -  The Seller shall be responsible
                 for the payment or performance of all salary, wages, bonuses,
                 earned vacations, vacation pay, sick leave, pensions, source
                 deductions, other remuneration and benefits, and all other
                 legal rights and entitlements of employment, including
                 maternity or parental benefits or pay equity obligations, if
                 any, for all the Employees accruing during or relating to the
                 period up to the First Closing Time (collectively, the
                 "RIGHTS, REMUNERATION AND BENEFITS") other than the Severance
                 Costs (as defined in Section 7.17(d)) for which Asset Acquiror
                 or Lafarge Canada, as the case may be, have assumed liability
                 under Sections 7.17(d), (e) and (f).  Asset Acquiror and
                 Lafarge Canada, as the case may be, shall be responsible,
                 conditional on Closing, for the payment and performance of all
                 Rights, Remuneration and Benefits accruing during or relating
                 to the period after the First Closing Time for all the
                 Employees who become employed by Asset Acquiror or Lafarge
                 Canada other than the Severance Costs for which Seller has
                 assumed responsibility under Section 7.17(f).

         (d)     SALARIED EMPLOYEES REFUSING OFFER - Asset Acquiror or Lafarge
                 Canada, as the case may be, shall assume and be liable for the
                 payment of all legal obligations relating to the termination
                 of employment of any Salaried Employee who does not accept an
                 offer to become an employee of the Asset Acquiror or Lafarge
                 Canada, as the case may be ("REFUSING SALARIED EMPLOYEE"), and
                 who is not offered a substantially similar position by the
                 Seller (provided that it is acknowledged that the Seller is
                 under no obligation to do so) including severance pay, notice
                 of termination of employment or pay in lieu of such notice,
                 damages for wrongful dismissal and any interest, award,
                 judgment or costs relating thereto in respect of the periods
                 of employment of the employee both before and after the First
                 Closing Time (collectively, "SEVERANCE COSTS").

         (e)     SUBSEQUENT OBLIGATIONS TO SALARIED EMPLOYEES - The Asset
                 Acquiror or Lafarge Canada, as the case may be, shall assume
                 and be liable for the payment of all Severance Costs relating
                 to the termination of employment after the First Closing Time
                 of any Salaried Employee who becomes employed by the Asset
                 Acquiror or





                                       49
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                                                   SIGNATURE COPY - JUNE 3, 1998


                 Lafarge Canada, as the case may be, and Seller shall assume
                 and be liable for the payment of all Severance Costs relating
                 to the termination of employment after the First Closing Time
                 of any Salaried Employee who becomes or remains in the employ
                 of the Seller.

         (f)     HOURLY EMPLOYEES - Asset Acquiror or Lafarge Canada, as the
                 case may be, shall assume and be liable for the payment of all
                 Severance Costs relating to the termination of employment,
                 after the First Closing Time, of any Hourly Employee employed
                 by Asset Acquiror or Lafarge Canada, as the case may be
                 ("TERMINATED HOURLY EMPLOYEE"), unless that Terminated Hourly
                 Employee exercises a right under a Collective Agreement to
                 displace another hourly employee of Seller (a "BUMPING
                 RIGHT"), in which case Asset Acquiror or Lafarge Canada, as
                 the case may be, shall assume and be liable for the payment of
                 all Severance Costs relating to the termination of employment
                 of any hourly employee of Seller resulting from  the exercise
                 of the Bumping Right by that Terminated Hourly Employee.  If
                 in any other circumstance an Hourly Employee exercises a
                 Bumping Right, Asset Acquiror or Lafarge Canada, as the case
                 may be, shall assume and be liable for the payment of all
                 Severance Costs relating to the termination of employment of
                 any hourly employee of Seller resulting from the exercise of
                 the Bumping Right by that Hourly Employee.  Similarly, if the
                 employment of any Hourly Employee with Asset Acquiror or
                 Lafarge Canada, as the case may be, is terminated because an
                 hourly employee of Seller has exercised a right under a
                 Collective Agreement to displace an Hourly Employee, Seller
                 shall assume and be liable for the payment of all Severance
                 Costs relating to the termination of employment of that Hourly
                 Employee.

7.18     Workers' Compensation.  On or before Closing, the Seller shall provide
a clearance certificate or other similar documentary evidence from the Worker's
Compensation authority in Ontario certifying that there are no outstanding
assessments, penalties, fines, levies, charges, surcharges or other amounts due
or owing to those authorities or if such certification is not forthcoming from
the relevant authority, a certificate of a senior officer of Seller as to those
matters shall be sufficient.  The Seller shall be and remain responsible for
any and all Worker's Compensation assessments,





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penalties, fines, levies, charges, surcharges or other amounts due or owing
with respect to the period prior to the Closing Date.  Notwithstanding the
foregoing, the Seller shall be entitled to any rebate, refund or other payment
which is owed or may become due under workers' compensation or similar
legislation in respect of any period prior to Closing.

7.19     Group Plans.

         (a)     Effective as of the Closing Date, but subject to subsections
7.19(b) and 7.19(c) hereof and any applicable requirements of the Collective
Agreement, Accepting Employees shall cease to participate in and receive
benefits under the Group Plans other than the Seller's Pension Plans (which are
separately addressed under Section 7.20) and shall commence participation in
non-pension group benefit plans which shall be existing or be established by
Lafarge Canada and the Asset Acquiror (the "ACQUIROR'S NON-PENSION BENEFIT
PLANS").

         (b)     The Seller shall retain responsibility under the Seller's
Group Plans (other than Pension Plans) for all amounts payable by reason of or
in connection with any and all claims incurred by the Accepting Employees prior
to the Closing Date.  The Seller shall also retain responsibility for the
benefits of all Sellers' employees who have retired or been terminated prior to
Closing.  Lafarge Canada shall be responsible for any and all claims of
Accepting Employees under the Acquiror's Non-Pension Benefit Plans which relate
to claims which are incurred with respect to events after the Closing Date.
For the purposes of this subsection 7.19(b), a claim shall be deemed to have
been "incurred" on the date of occurrence of an injury, the diagnosis of an
illness or on the date of any other event giving rise to such claim or series
of related claims.  The Seller shall pay all such invoices when due in
accordance with the provisions of the Seller's Group Plans.

         (c)     In administering the Acquiror's Non-Pension Benefit Plans for
the Accepting Employees after the Closing Date, Lafarge Canada will grant full
credit to each Accepting Employee for all years of service of such Accepting
Employees for all purposes (including determination of statutory, common law
and any other severance benefits) for which such years of service were
recognized by the Seller under the terms of the Seller's Group Plans.  Any
deductibles and out-of-pocket maximums under the terms of the Acquiror's
Non-Pension Benefit Plans shall be reduced in proportion to that portion of the
calendar year preceding the Closing Date.





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7.20     Pension Plans.  The following provisions shall apply with respect to
the Pension Plans:

         (a)     The Accepting Employees who participate in the Queenston
Hourly Rated Employees Pension Plan shall, from and after the Closing Date,
continue to participate in and accrue benefits thereunder.  On the Closing
Date, the Seller shall enter into an assignment and assumption agreement in the
form set out in Schedule 7.20(a) so as to assign to the Asset Acquiror all
right, title and interest in and to the Queenston Hourly-Rated Employees
Pension Plan and the Asset Acquiror shall assume all duties, obligations and
liabilities relating to such Plan.

         (b)(i)  Defined Terms.

         In this subsection 7.20(b), in addition to the definitions contained
elsewhere in this Agreement:

         "ADJUSTED ASSET AMOUNT" has the meaning given to that term in
paragraph 7.20(b)(vi) of this Agreement.

         "APPLICABLE PENSION LEGISLATION" means all legislation that applies to
the Seller's Plans or the Asset Acquiror's Plans as the case may be, including
the Pension Benefits Act (Ontario) and the Income Tax Act (Canada);

         "ASSET ACQUIROR'S PLANS" means the Lafarge Canada Inc. Salaried
Employees' Pension Plan and a new plan, the name of which has not yet been
decided, in respect of the Accepting Employees who are presently members of the
Seller's Redland Quarries Inc. - Dundas Hourly-Rated Employees Pension Plan,
and "ASSET ACQUIROR'S PLAN" means either one of them.

         "CLOSING DATE LIABILITIES" means, for each of the Seller's Plans, the
greater of going concern liabilities and solvency liabilities respecting the
Transferred Employees under the applicable Seller's Plan calculated in the
aggregate and for each Transferred Employee as of the Closing Date in
accordance with the actuarial methods, assumptions and principles set out in
Schedule 7.20(b);

         "FINAL ASSET AMOUNT" means the amount of assets in each of  the
Segregated Accounts on each of the respective Transfer Dates;

         "INITIAL SEGREGATED AMOUNT" in respect of each of the respective
Seller's Plans has the meaning given to that term in paragraph 7.20(b)(iv) of
this Agreement;

         "PRO-RATA EXPENSES" means the proportion of ordinary course fees
concerning administration of the Seller's Plans, respectively, and their
associated respective funds that Closing





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Date Liabilities is of the greater of going concern liabilities and solvency
liabilities as of the Closing Date of the respective Seller's Plans;

         "REGULATORY AUTHORITIES" means the Pension Commission of Ontario, the
Superintendent of Pensions for Ontario, Revenue Canada, Customs, Excise and
Taxation and any other Governmental Entity responsible for or having
jurisdiction over the regulation of pension plans;

         "REPORT" has the meaning given to that term in paragraph 7.20(b)(ii)
of this Agreement;

         "SEGREGATED ACCOUNT" means a separate account for each of the Seller's
Plans established with the funding agency of the respective Seller's Plans to
hold assets of the pension fund of the Seller's Plans, respectively, in respect
of the Transferred Employees on a segregated basis within the pension fund and
in accordance with paragraph 7.20(b)(iv) of this Agreement;

         "SEGREGATION DATES" has the meaning given to that term in paragraph
7.20(b)(iv) of this Agreement;

         "SELLER'S PLANS" means the: (i) Redland Quarries Inc. - Dundas
Hourly-Rated Employees Pension Plan (Rev. Can.  0324640); and  (ii) Redland
Quarries Inc. and Affiliated Companies Salaried Employee Pension Plan (Rev.
Can. 0243287); and "SELLER'S PLAN" means either one of them;

         "TRANSFER DATES" means the respective dates upon which assets in
respect of the respective Transferred Employees are transferred from the
respective Seller's Plan to the corresponding Asset Acquiror's Plan pursuant to
paragraph 7.20(b)(vii) of this Agreement;

         "TRANSFERRED EMPLOYEES" means the Accepting Employees  who were
members of any of  the Seller's Plans on the Closing Date or were employed in
service leading to eligibility for such membership;

(ii)     Determination of Closing Date Liabilities.  As soon as practicable
         after the Closing  Date, the Seller  shall cause its actuaries to
         update the pension records of all Transferred Employees and to prepare
         and deliver to the Seller a report (the "REPORT") setting out the
         Closing Date Liabilities in respect of each of the Seller's Plans.

                 Within 15 days of receiving each Report, the Seller shall
         provide a copy of the Report to the Asset Acquiror together with
         copies of all information and data used in connection with determining
         the Closing Date Liabilities for the applicable Seller's Plan and
         preparing





                                       53
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                                                   SIGNATURE COPY - JUNE 3, 1998


         such Report and any other information or data which the Asset Acquiror
         or its agents may reasonably request.

                 The Asset Acquiror shall notify the Seller within 30 days of
         receiving a copy of each Report from the Seller as to whether it
         agrees or disagrees with any of the Closing Date Liabilities set out
         in that particular Report.  If the Asset Acquiror fails to provide
         such notice to the Seller, the Asset Acquiror shall be deemed to have
         approved of the Closing Date Liabilities for the applicable Seller's
         Plan.  If the Asset Acquiror notifies the Seller that it disagrees
         with any of the Closing Date Liabilities set out in the Report, the
         Seller and the Asset Acquiror shall forthwith negotiate in good faith
         to reach agreement respecting such amount or amounts.  If within 15
         days after commencing negotiations, the Seller and the Asset Acquiror
         are unable to agree on the disputed Closing Date Liabilities, the
         matter shall forthwith be referred to an independent firm of actuaries
         (acting as experts and not arbitrators) acceptable to both the Seller
         and the Asset Acquiror with a direction to determine the disputed
         amount or amounts within 60 days of the referral.  The cost of the
         independent firm of actuaries shall be borne equally by the Seller and
         the Asset Acquiror.  The determination by the independent firm of
         actuaries of the disputed Closing Date Liabilities shall be final and
         binding upon the Seller and the Asset Acquiror and the Seller and the
         Asset Acquiror shall be deemed to have agreed on such amounts.

(iii)    Application for Regulatory Approval of Asset Transfer  As soon as
         practicable after the Seller and Asset Acquiror agree or are deemed to
         agree on the Closing Date Liabilities in respect of a Seller's Plan,
         the Seller shall apply, where required by Applicable Pension
         Legislation, to the relevant Regulatory Authorities for approval to
         transfer the Final Asset Amount in respect of such Seller's Plan to
         the corresponding Asset Acquiror's Plan.  The Seller shall prepare all
         applications, reports and other materials required under Applicable
         Pension Legislation or by the applicable Regulatory Authority in
         respect of each of the Seller's Plans to obtain such approval and
         shall diligently pursue all applications.  Before filing any
         application to obtain approval for the transfer of any Final Asset
         Amount, the





                                       54
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                                                   SIGNATURE COPY - JUNE 3, 1998


         Seller shall provide copies of the application materials to the Asset
         Acquiror for its review.  The Seller shall make any changes to the
         application materials in respect of any of the Seller's Plans that the
         Asset Acquiror shall reasonably request, provided that the Asset
         Acquiror gives notice of the requested changes to the Seller within 30
         days of receiving the relevant application materials.

(iv)     Segregation of Assets  As soon as practicable after the Seller and
         Asset Acquiror agree or are deemed to agree on the Closing Date
         Liabilities for each of the Seller's Plans, the Seller shall cause (i)
         the Segregated Account for each Seller's Plan to be established, and
         (ii) cash and such other assets which are acceptable to the Asset
         Acquiror to be placed within each Segregated Account (the "INITIAL
         SEGREGATED AMOUNTS") equal to the respective Closing Date Liabilities
         less benefit and other payments made from the respective pension funds
         of the Seller's Plans concerning the respective Transferred Employees
         and respective Pro-Rata Expenses for the period from the Closing Date
         to the respective dates of  segregation (the "SEGREGATION DATES") and
         plus or minus, as the case may be, an amount calculated with respect
         to the Initial Segregation Amounts for the period from the Closing
         Date to the respective Segregation Dates by applying the applicable
         fund rate of return or loss for the same period, such rate of return
         to be determined by Seller, in consultation with its actuary, in
         accordance with generally accepted accounting and actuarial principles
         for the respective Seller's Plan, and which calculation and
         determination of the applicable fund rate of return or loss shall be
         subject to review and confirmation by Asset Acquiror within 30 days of
         the delivery to the Asset Acquiror of the pro forma calculation and
         determination.

                 The administration of any amounts in any Segregated Account
         shall at all times be the responsibility of the Seller, acting on
         behalf of the Asset Acquiror.  The Asset Acquiror shall provide to the
         Seller such information as is in the possession or control of the
         Asset Acquiror and is reasonably required by the Seller to administer
         the amounts in the Segregated Accounts and to make benefit and other
         payments to the Transferred Employees pursuant to paragraph 7.20(b)(v)
         of this Agreement.  The Seller may charge to the respective Segregated
         Accounts all reasonable expenses arising in connection with the
         respective Segregated Accounts together with the respective Pro-Rata
         Expenses for the period from the





                                       55
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                                                   SIGNATURE COPY - JUNE 3, 1998


         respective Segregation Dates to the respective Transfer Dates.  From
         the respective Segregation Dates to the respective Transfer Dates, the
         Asset Acquiror shall at its sole expense, which may be paid or
         otherwise deducted from the Segregated Accounts, provide or arrange
         for the investment management of all amounts in the Segregated
         Accounts and the Seller shall ensure that the funding agent or agents
         of the respective Seller's Plans follows the investment management
         directions of the Asset Acquiror or its agents.

                 The Asset Acquiror agrees to indemnify the Seller in respect
         of any claims, demands, actions, causes of actions, damages, losses,
         costs, liabilities or expenses which the Seller may suffer as a result
         of or in connection with the Asset Acquiror or its agents providing
         investment management services respecting accounts in any Segregated
         Account, save and except for circumstances involving the wilful
         default or negligence of the Seller.

                 Prior to Closing or, in any event, no later than the first
         Segregation Date, in order to enable Asset Acquiror to property invest
         the Segregated Accounts without adversely affecting the Seller or the
         Seller's Plans, the Seller shall provide to Asset Acquiror all
         relevant information with respect to the structure and investments of
         the Seller's Plans, including the Statement of Investment Policies and
         Goals and any other document indicating any investment limitation with
         respect to the Seller's Plans in effect at the Closing Date and shall
         keep Asset Acquiror informed on a timely basis of any changes to any
         of the foregoing through to the date that the Final Asset Amount or
         Adjusted Asset Amounts, as the case may be, are transferred in
         accordance with Section 7.20(b)(vii).

(v)      Benefit Payments.  The Seller shall ensure that, in respect of each of
         the Seller's Plans, from the Closing Date to the Segregation Date any
         benefit and other payments due and owing to, or in respect of, any
         Transferred Employee from such Seller's Plan are paid to the
         Transferred Employee or his or her named beneficiary.  Before the
         Segregation Date, such payments shall be made from the general assets
         of the relevant Seller's Plan.  After the Segregation Date, such
         payments shall be made from the respective Segregated Account.

(vi)     Refusal to Permit Transfer.  The Seller shall forthwith notify the
         Asset Acquiror if any Regulatory Authority to whom the Seller has
         applied to approve the transfer of the Final Asset Amount from any
         Seller's Plan to the corresponding Asset Acquiror's Plan refuses to





                                       56
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                                                   SIGNATURE COPY - JUNE 3, 1998


         approve such transfer and directs either that a different amount be
         transferred or that an assumption or method of calculation used
         pursuant to this Agreement to determine the respective Closing Date
         Liabilities be changed.  In such event, the Seller and Asset Acquiror
         agree that the amount to be transferred (the "ADJUSTED ASSET AMOUNT")
         shall be determined in accordance with the Regulatory Authority's
         direction, subject to the Seller's and the Asset Acquiror's right to
         appeal such direction until all rights of appeal are exhausted to any
         Governmental Entity or court where the Seller or the Asset Acquiror,
         as applicable, on the advice of their respective professional
         advisors, is of the opinion that such direction is not required under
         Applicable Pension Legislation.

(vii)    Transfer to Asset Acquiror's Plans.  Within 30 days of receiving the
         written approval of the applicable Regulatory Authorities to transfer
         the respective Final Asset Amounts or Adjusted Asset Amounts, as the
         case may be, and of receiving notice from the Asset Acquiror of the
         registration of the respective Asset Acquiror's Plan, the Seller shall
         transfer or cause the funding agent of the respective Seller's Plan to
         transfer to the funding agent of the corresponding Asset Acquiror's
         Plan:

         (A)     in the case of approval to transfer the Final Asset Amount,
                 the Final Asset Amount;

         (B)     in the case of approval to transfer the Adjusted Asset Amount
                 where such amount exceeds the Final Asset Amount, the amount
                 of such excess from the pension fund of the applicable
                 Seller's  Plan together with the Final Asset Amount; and

         (C)     in the case of approval to transfer the Adjusted Asset Amount
                 where such amount is less than the Final Asset Amount, only
                 the Adjusted Asset Amount from the applicable Segregated
                 Account.

                          Where subparagraph (C) applies, the balance in the
                 Segregated Account may be released within the applicable
                 Seller's Plan.

(viii)   Accrual of Benefits.  As of the Closing Date, those of  the
         Transferred Employees who are actively participating in any Seller's
         Plan shall cease to participate actively in, and accrue benefits
         under, the respective Seller's  Plan and shall commence participation
         in the corresponding Asset Acquiror's Plan.





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                                                   SIGNATURE COPY - JUNE 3, 1998


(ix)     Recognition of Past Service.   Subject to receipt by the funding agent
         or agents of the respective Asset Acquiror's  Plans of the Final Asset
         Value or Adjusted Asset Amount, as the case may be, from the
         corresponding Seller's Plan pursuant to paragraph 7.20(b)(vii) of this
         Agreement, the Asset Acquiror shall ensure that the applicable Asset
         Acquiror's Plan recognizes the period of service of the Transferred
         Employees recognized under the corresponding Seller's Plan prior to
         the Closing Date for all purposes relating to pension benefits as if
         such service had been with the Asset Acquiror.  Without limiting the
         foregoing, Asset Acquiror covenants and agrees to establish or amend
         or cause to be established or amended as applicable the respective
         Asset Acquiror's Plans to the extent necessary to give effect to its
         obligations under this Section 7.20(b)(ix).  As soon as practicable
         after the Closing Date, Asset Acquiror shall apply to the Regulatory
         Authorities for registration or approval of all documents prepared for
         the purposes of establishing or amending, as applicable, the Asset
         Acquiror's Plans.  The Asset Acquiror shall diligently pursue all
         necessary applications to the Regulatory Authorities. The Asset
         Acquiror shall forthwith notify the Seller of the registration of the
         documents prepared in respect of each of the Asset Acquiror's Plans as
         contemplated herein.

(x)      Asset Acquiror Assumes Liabilities.  Subject to receipt by the funding
         agent or agents of the respective Asset Acquiror's Plan of the Final
         Asset Amount or Adjusted Asset Amount, as the case may be, from the
         corresponding Seller's Plan pursuant to paragraph 7.20(b)(vii) of this
         Agreement, the Asset Acquiror and Lafarge Canada hereby assume
         liability for, and indemnify and hold harmless the Seller against,
         payment of pension and ancillary benefits (excluding, for greater
         certainty, surplus) accrued by Transferred Employees or their
         beneficiaries, as applicable, up to and including the Closing Date
         under the respective Seller's Plans and payment of pension and other
         benefits accrued by Transferred Employees or their beneficiaries, as
         applicable, after the Closing Date under the respective Asset
         Acquiror's  Plan.

(xi)     As soon as is practicable, but in any event within 120 days of the
         Closing Date, the Seller and the Asset Acquiror and Lafarge Canada
         shall enter into a reciprocal transfer agreement in respect of the
         Redland Quarries Inc. - Dundas Hourly-Rated Employees Pension Plan and





                                       58
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                                                   SIGNATURE COPY - JUNE 3, 1998


         the corresponding Asset Acquiror's Plan which is to become a successor
         thereto, which reciprocal transfer agreement shall provide, in respect
         of bargaining unit employees who are plan members and who exercise a
         Bumping Right to transfer to or from employment with either the Seller
         or the Asset Acquiror or Lafarge Canada, as the case may be, for (A)
         the recognition under the transferee plan of prior service recognized
         under the transferor pension plan and an assumption of liabilities
         thereunder; (B) a transfer of assets in respect of the foregoing on a
         prescribed actuarial basis (both assumptions and methods) to be made
         annually within 90 days of the calendar year of the transfer; (C) the
         termination of the agreement on 60 days advance notice by either the
         Seller or the Asset Acquiror or Lafarge Canada, as the case may be, or
         immediately upon the occurrence of mutually agreeable events; and (D)
         such other terms and conditions as the parties shall agree are
         necessary or desirable to address the relevant pension issues which
         arise in connection with the exercise or possible exercise of Bumping
         Rights by Plan members, provided that all transfers which have
         occurred prior to such termination will be processed in accordance
         with the terms of such reciprocal transfer agreement.

7.21     Revised Dewatering Permit.

         (a)     In this section 7.21, in addition to the definitions contained
elsewhere in this Agreement:

         "10 YEAR RESERVES" means 43 million tonnes of aggregate, including
dolomitic metallurgical limestone, reserves in the first bench of the North
Quarry Site, which the Parties have agreed is the estimated amount of such
reserves that have yet to be mined on the Closing Date.

         "BASE RESERVES" means 119.6 million tonnes of aggregate, including
dolomitic metallurgical limestone, reserves in the first and second bench of
the North Quarry Site, which the Parties have agreed is the estimated amount of
such reserves that have yet to be mined on the Closing Date.

         "DRY MINING" means quarry mining for dolomitic metallurgical stone and
aggregates using mining techniques and methods other than the techniques and
methods that would customarily be used for the quarry mining of submerged
dolomitic metallurgical stone and aggregates and "DRY MINED" or "DRY MINE"
shall have a corresponding meaning.

         "DRY RESERVES" has the meaning ascribed thereto in Section 7.21(d).





                                       59
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                                                   SIGNATURE COPY - JUNE 3, 1998


         "ENGINEER" has the meaning ascribed thereto in Section 7.21(c).

         "EVALUATION DAY" means the earlier of the following days:

                 (i)      the day of the issue of a final unappealable decision
                          of the Ministry not to issue any revised permit to
                          take water from the North Quarry Site which permits
                          dewatering in addition to that authorized by Seller's
                          permit to take water from the North Quarry Site in
                          effect immediately before the Closing Date; and

                 (ii)     the day which is two years after the Closing Date.

                 For purposes of this definition, "unappealable" means that
                 Seller, Asset Acquiror and Lafarge Canada are also prohibited
                 by Law from further applying or re-applying for a revised
                 permit to take water from the North Quarry Site.

         "ISSUED DEWATERING PERMIT" means, failing the issue of the Required
Dewatering Permit on or before the Evaluation Day, the highest volume (measured
in imperial gallons per minute) permit or revised permit to take water from the
North Quarry Site issued by the Ministry on, before or within two years after
the Closing Date.

         "MINISTRY" means the Ontario Ministry of Environment and Energy

         "REPORT" means the report of the Engineer as provided under Section
7.21(d).

         "REQUIRED DEWATERING PERMIT" means a revised permit to take water from
the North Quarry Site issued by the Ministry, either in the name of or validly
assigned to Lafarge Canada, for a dewatering volume of not less than 2400
imperial gallons per minute.

         "RESERVES COMPENSATION PAYMENT" has the meaning ascribed thereto in
Section 7.21(e).

         (b)     The Parties acknowledge that as at the date of this Agreement,
Seller has already submitted to the Ministry its application for the Required
Dewatering Permit.  If the Required Dewatering Permit is issued at any time on
or before the Evaluation Date, subsections 7.21(c), (d), (e), (f) and (g) of
this Section 7.21 shall cease to apply and, in particular, the provisions of
Section 7.21(e) regarding the Reserves Compensation Payment shall be of no
force or effect, and Seller shall thereby be fully released and discharged from
its obligations under this Section 7.21.  If the Required Dewatering Permit has
not issued by the Closing Date, then Seller shall have the period after the
Closing Date up to and including the Evaluation Date to continue seeking the
Required Dewatering





                                       60
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                                                   SIGNATURE COPY - JUNE 3, 1998


Permit.  During such period, Lafarge Canada shall and shall cause its
Affiliates to fully assist and co-operate with Seller in its efforts to obtain
the Required Dewatering Permit.

         (c)     Unless the Required Dewatering Permit has issued on the
earlier of: (i) the Evaluation Day; and (ii) the day that is one year after the
Closing Date, Seller and Lafarge Canada shall engage a qualified Ontario
professional mining engineer (the "ENGINEER") for purposes of preparing, if
necessary, the Report.  If the Parties cannot agree as to the selection of the
Engineer, then the matter of the selection shall be referred to the Chairman
(or equivalent) of the professional body in Ontario governing engineers, whose
selection of the Engineer shall be determinative and binding on the Parties
without any right of appeal.  The procedures applicable to the preparation of
the Report by the Engineer are set forth in Section 7.21(f).  In preparing the
Report and carrying out its other duties under this Agreement, the Engineer
shall be acting as expert and not arbitrator and its decisions and
determinations, including, without limitation, the final Report, shall be final
and binding upon the Parties for all purposes and there shall be no appeal
therefrom.

         (d)     Unless the Required Dewatering Permit has issued, on the
earlier of : (i) the Evaluation Date; and (ii) that date that is 18 months
after the Closing Date, the Parties shall direct the Engineer to prepare a
report (the "REPORT") which sets forth the Engineer's determination of the
number of tonnes of aggregate, including dolomitic metallurgical stone,
reserves in the North Quarry Site which can be Dry Mined given the volume of
dewatering permitted under the Issued Dewatering Permit in effect at the time
of the commencement of the preparation of the Report (which amount shall
include the number of tonnes actually Dry Mined between the Closing Date and
the date of issue of the Report) (the "DRY RESERVES").  If the Report is
prepared before the Evaluation Date, the Report shall be updated as of the
Evaluation Date to account for any increased Issued Dewatering Permit issued
during the period in which the Report was in preparation.

         (e)     Not more than 10 days after receipt of the final Report or the
Evaluation Date, whichever is later, the Seller shall deliver to Lafarge
Canada, if applicable, a certified cheque or bank draft payable to Lafarge
Canada for the amount (the "RESERVES COMPENSATION PAYMENT"), if any, calculated
according to the following formula:





                                       61
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                                                   SIGNATURE COPY - JUNE 3, 1998



                 (X-Y)-(Z-Y) x Cdn. $20,000,000 = Reserves Compensation Payment
                 -----------
                    (X-Y)

                 where:

                 X is the number of tonnes of the Base Reserves;

                 Y is the number of tonnes of the 10 Year Reserves; and

                 Z is the number of tonnes of Dry Reserves.

         (f)     The following provisions shall apply concerning the Engineer
and the preparation and delivery of the Report:

                 (i)      Lafarge Canada and Seller shall enter into an
         engagement agreement with the Engineer containing customary terms and
         provisions, including customary indemnification of the Engineer.  Any
         procedural matters not addressed in this Section 7.21(f) shall be
         determined by the Engineer in his discretion, and, to the extent that
         submissions of the Parties are specified to be made in writing, the
         Engineer shall, on his initiative, have the discretion to receive
         submissions and information by any other method acceptable him
         including oral submissions, meetings, site visits, etc.

                 (ii)     Lafarge Canada and Seller shall each prepare a
         written submission on the subject matters of the Report which
         (together with the relevant documents) shall be submitted to the
         Engineer and to each other as soon as possible after the date that the
         Engineer is directed to proceed to prepare the Report (the
         "COMMENCEMENT DATE"), and, in any event, within 15 days of the
         Commencement Date, to facilitate the preparation and delivery of a
         draft Report within 60 days of the Commencement Date.

                 (iii)    Seller and Lafarge Canada shall each provide the
         Engineer with all information which it reasonably requires and the
         Engineer shall be entitled to prepare the Report based on such
         information as it considers appropriate.

                 (iv)     Within 60 days of the date of his appointment, the
         Engineer shall issue a draft Report to each of the Parties.  Each of
         the Parties shall then have a further 21 day period to, at their
         option, prepare and deliver to the Engineer and to the other Party a
         written response to the draft Report.





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                 (v)      Within 21 days after the later of: (A) the Evaluation
         Date; and (B) the date that the Engineer has received the response of
         both Parties to the draft Report, the Engineer shall issue its final
         Report and shall deliver a copy to Seller and to Lafarge Canada,
         provided that, if an increased Issued Dewatering Permit has issued and
         is not reflected in the draft Report, the Engineer shall prepare and
         issue a supplemented draft Report to the Parties and  shall provide
         them with a reasonable opportunity to comment on the supplemented
         draft Report before finalizing the Report and in these circumstances,
         the time lines regarding the delivery to the Parties of the final
         Report shall be adjusted accordingly.

                 (vi)     The expenses of the Engineer in preparing the Report
         shall be shared equally by Seller and Lafarge Canada.

         (g)     Seller represents and warrants to Lafarge Canada that the
permit to take water presently in effect with respect to the retention ponds at
the Dundas Site at the rate of 4,300 imperial gallons per minute is sufficient
to fully utilize the Required Dewatering Permit, if and when issued, provided
that Lafarge Canada manages the water on the Dundas Site in a commercially
reasonable manner.  Seller shall indemnify and hold harmless Lafarge Canada
against any Liabilities suffered or incurred by Lafarge Canada, its successors
or assigns, resulting from any inaccuracy in or breach of the foregoing
representation and warranty in this Section 7.21(g), to the maximum aggregate
limit of Cdn.  $500,000 which amount shall include, without limitation, all
damages, interest, costs and expenses suffered or incurred by Lafarge Canada as
a result of such inaccuracy or breach.

7.22     Repayment of Obligations to the Companies.  Immediately prior to the
Closing, the Seller shall pay all obligations owed to any of the Companies (as
such term is defined in the United States Stock Purchase Agreement), except for
all debts outstanding between (i) the Companies, or any of them, on the one
hand and (ii) Seller, on the other hand, in respect of intra-group sales of
goods and services in the ordinary and usual course of business.

7.23     Lease of Lime Plant Site.  Seller, Asset Acquiror and Lafarge Canada
shall execute and deliver on the Closing Date the lease of the Lime Plant Site
in the form attached as Schedule 7.23 (the "LIME PLANT LEASE").





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                                  ARTICLE VIII

                         CONDITIONS TO THE TRANSACTIONS

8.1      Condition to the Obligations of Each Party.  The obligations of each
of the parties hereto to consummate the purchase and sale of the Purchased
Assets and the purchase and sale of the Purchased Shares are subject to the
condition that the purchase and sale contemplated by that certain Stock
Purchase Agreement of even date herewith among Redland International Limited,
Lafarge Corporation and  Lafarge S.A. (the "UNITED STATES STOCK PURCHASE
AGREEMENT") shall be consummated simultaneously with the Closing.

8.2      Conditions to the Obligations of Seller and Lafarge S.A..  The
obligation of Seller to consummate the purchase and sale of the Purchased
Assets and the Purchased Shares is subject to the satisfaction (or written
waiver by Seller) of each of the following further conditions:

         (a)     Share Acquiror and Lafarge Canada shall have performed and
complied with in all material respects all obligations and covenants required
to be performed or complied with by them under this Agreement at or prior to
the Closing Date, and Seller shall have received a certificate signed by an
authorized officer of each of Share Acquiror and Lafarge Canada on behalf of
Share Acquiror and Lafarge Canada to the foregoing effect;

         (b)     The representations and warranties of Share Acquiror and
Lafarge Canada made herein shall be true and correct in all material respects
as of the date of this Agreement and as of the Closing Date as though made on
and as of the Closing Date except: (i) to the extent such representations and
warranties are by their express provisions made as of a specified date, and
(ii) for the effect of transactions contemplated by this Agreement, and Seller
shall have received a signed certificate of an authorized officer of each of
Share Acquiror and Lafarge Canada, on behalf of Share Acquiror and Lafarge
Canada to the foregoing effect; and

         (c)     None of the Parties shall be subject to any order, decree, or
injunction of a court or agency of competent jurisdiction which enjoins or
prohibits the consummation of the transactions contemplated hereby and such
transactions shall not have been prohibited under any applicable Laws.





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         (d)     The Asset Acquiror and Lafarge Canada shall have executed and
delivered to the Seller a lime supply agreement (the "LIME SUPPLY AGREEMENT")
in form and content satisfactory to the Parties.

         (e)     Asset Acquiror and Lafarge Canada shall have executed and
delivered the  Lime Plant Lease.

         (f)     Deleted.

         (g)     Seller shall have received an opinion of McCarthy Tetrault,
counsel to Share Acquiror and Lafarge Canada, substantially in the form of
Schedule 8.2(g).

8.3      Conditions to the Obligations of Share Acquiror and Lafarge Canada.
The obligation of Asset Acquiror, Share Acquiror and Lafarge Canada to
consummate the purchase and sale of the Purchased Assets and the Purchased
Shares  is subject to the satisfaction (or written waiver by Share Acquiror and
Lafarge Canada) of each of the following conditions:

         (a)     Seller shall have performed and complied with in all material
respects all obligations and covenants required to be performed or complied
with by it under this Agreement at or prior to the Closing Date, and Share
Acquiror and Lafarge Canada shall have received a certificate signed by an
authorized officer of Seller, on behalf of Seller, to the foregoing effect.

         (b)     None of the Parties shall be subject to any order, decree
(other than consent decrees to which Share Acquiror has agreed), or injunction
of a court or agency of competent jurisdiction which enjoins or prohibits the
consummation of the transactions contemplated hereby.

         (c)     The representations and warranties of Seller and Lafarge S.A.
made herein shall be true and correct in all material respects as of the date
of this Agreement and as of the Closing Date as though made on and as of the
Closing Date except: (i) to the extent such representations and warranties are
by their express provisions made as of a specified date, (which need only be
true and correct in all material respects as of such date) and (ii) if the
inaccuracy of such representations and warranties does not constitute a
Material Adverse Effect.

         (d)     Lafarge S.A. shall have delivered to Share Acquiror and
Lafarge Canada the Guarantee in substantially the form attached hereto as
Schedule 8.3(e).





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         (e)     Except for the transactions contemplated by this Agreement,
there shall not have been any changes in the business, prospects or financial
condition of Seller that, individually or in the aggregate, have had or are
reasonably likely to have a Material Adverse Effect.

         (f)     The Board of Directors of  Lafarge Corporation shall have
received from SBC Warburg Dillon Read Inc., independent investment bankers, an
opinion, dated as of the date hereof and in form reasonably satisfactory to
such Board of Directors, as to the fairness, from a financial point of view, of
the transactions contemplated by this Agreement.

         (g)     Lafarge Corporation shall have received all necessary
shareholder approvals relating to the purchase transactions contemplated
hereunder.

         (h)     Lafarge Canada shall have received an opinion of Miller
Thomson counsel to Seller, and an opinion of in-house or other, counsel to
Lafarge S.A., substantially in the forms attached hereto as Schedule 8.3(i).

         (i)     Lafarge Canada shall have received from each of Seller and
Lafarge S.A. a certificate, dated as of the Closing Date, duly executed by an
authorized officer of each, to the effect of (a) and (c) above.

         (j)     Receipt of Closing Documentation. All instruments of
conveyance and other documentation and assurances relating to the sale and
purchase of the Purchased Assets and the Purchased Shares including, without
limitation, share certificates, assignments of the Contracts, the Equipment
Leases and the Licenses (and consents to such assignments, where required),
bills of sale, motor vehicle transfers and documentation, and all actions and
proceedings taken on or prior to the Closing in connection with performance by
the Seller of its obligations under this Agreement shall be satisfactory to the
Share Acquiror and Lafarge Canada and their counsel, acting reasonably, and the
Share Acquiror and Lafarge Canada shall have received copies of all such
documentation or other evidence as it may reasonably request in order to
establish the consummation of the transactions contemplated under this
Agreement and the taking of all corporate proceedings in connection with those
transactions in compliance with this Subsection 8.3(k), in form (as to
certification and otherwise) and substance satisfactory to the Share Acquiror
and Lafarge Canada and their respective counsel.





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         (k)     Consents to Assignment. All consents or approvals from or
notifications to any lessor or other third Person required under the terms of
any of the Contracts, Equipment Leases, or the Licenses with respect to their
assignment to the Asset Acquiror, or otherwise in connection with the
consummation of the transactions contemplated under this Agreement, shall have
been duly obtained or given, as the case may be, on or before the Closing Time.

         (l)     Lime Plant Lease.  The Seller shall have executed and
delivered to the Asset Acquiror and Lafarge Canada the Lime Plant Lease.

         (m)     Directors of Asset Acquiror. There shall have been delivered
to the Share Acquiror and Lafarge Canada on or before the Closing, the
resignations, effective as and from Closing, of all of the directors and
officers of Asset Acquiror appointed by or at the request of Seller, together
with releases from each such person of all their claims respectively.

         (n)     Lime Supply Agreement.  The Seller shall have executed and
delivered to the Asset Acquiror and Lafarge Canada the Lime Supply Agreement.

                                   ARTICLE IX

                                  TERMINATION

9.1      Termination.  This Agreement may be terminated and the transactions
contemplated hereby may be abandoned at any time prior to the Closing:

         (a)     by written consent of Seller, Lafarge S.A. and Lafarge Canada

         (b)     by the Board of Directors of either Seller or Lafarge Canada
at any time after June 30, 1998, if the transactions contemplated hereunder
shall not theretofore have been consummated; provided, that Seller or Lafarge
Canada, as the case may be, may not seek termination pursuant to this Section
9.1(b) if the failure to consummate the transactions contemplated hereunder is
caused by the action or inaction, in violation of this Agreement, of the Party
seeking such termination.

         (c)     by either Seller or Lafarge Canada if a condition to its
obligation to perform becomes incapable of fulfillment; provided, that Seller
or Lafarge Canada, as the case may be, may not seek termination pursuant to
this Section 9.1(c) if such condition is incapable of fulfillment due to the
failure of Seller or Lafarge Canada, as the case may be, to perform any of the
agreements set forth herein required to be performed by such party, at or
before the Closing; or





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         (d)     by the Board of Directors of either Seller or Lafarge Canada
if any Governmental Entity whose approval is required for the consummation of
the transactions contemplated hereby shall have denied approval of such
transactions and such denial has, after exhaustion of any and all available
appellate procedures, become final.

9.2      Effect of Termination.  In the event of the termination of this
Agreement pursuant to Section 9.1 hereof, this Agreement, except for the
provisions of Sections 9.1(c), 11.6, 12.4, 12.7 and 12.9, shall forthwith
become null and void and have no effect, without any liability on the part of
either party or their respective directors, officers or shareholders.  Nothing
in this Article IX shall, however, relieve either party to this Agreement of
liability for breach of this Agreement occurring prior to such termination, or
for breach of any provision of this Agreement which specifically survives
termination hereunder.

                                   ARTICLE X

                                    CLOSING

10.1     Closing.  Unless this Agreement has been terminated and the
transactions contemplated under this Agreement have been abandoned pursuant to
Section 9.1 and subject to the fulfillment or, if permitted, waiver of the
conditions set forth in Article VIII, the closing of the transactions
contemplated under this Agreement  (the "CLOSING") will take place at the
offices of Miller Thomson, 20 Queen Street West, Suite 2500, Toronto, Ontario,
Canada M5H 3S1, commencing at 10:00 a.m. (Toronto time) on June 3, 1998 unless
another date or time is agreed to in writing by the parties to this Agreement
(the "CLOSING DATE").  The Closing will be effective as of 11:59 p.m. on May
31, 1998.

                                   ARTICLE XI

                           SURVIVAL; INDEMNIFICATION

11.1     Survival of Representations, Warranties and Covenants.  The several
representations and warranties of the parties contained in this Agreement, and
the covenants of Seller contained in Sections 11.2(a) (except as set forth in
the following provisos),11.2(b) (except as set forth in the





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following provisos) and 11.2(e) will survive the Closing until the expiration
of 18 months after the Closing Date, except with respect to claims asserted by
Written Notice by Lafarge Canada or Seller with respect to such
representations, warranties and covenants prior to such expiration in which
case they will survive until the resolution of such claims; provided, however,
that (i) the representations and warranties of Seller contained in Sections
5.2, 5.3, 5.6, 5.9 (but only to the extent relating to the Seller's Plans),
5.12 (but only to the extent relating to title) and 5.33, and the covenants of
Seller contained in Sections 11.2(b) (to the extent relating to a breach of the
foregoing specified representations), 11.2(c) and 11.2(d) and the
representations and warranties of Lafarge Canada contained in Section 6.2  and
the covenants of Lafarge Canada contained in Section 11.3 will remain operative
and in full force and effect until the expiration of any applicable statute of
limitations (giving effect to any tolling, waiver or extension thereof) and, if
there is no applicable statute of limitations, then without any time
limitation, except with respect to claims asserted by Written Notice by Lafarge
Canada or Seller with respect to such representations, warranties and covenants
prior to such expiration in which case they will survive until the resolution
of such claims,  and (ii) the representations and warranties contained in
Section 5.7(d) and the covenants contained in Section 11.2(f) shall survive
until the fifth anniversary of the Closing Date except with respect to claims
asserted by Written Notice by Lafarge Canada or Seller will respect to such
representations, warranties and covenants prior to such expiration in which are
they will survive until the resolution of and claims.  The other covenants of
the parties contained in this Agreement (or in any document delivered in
connection herewith) will remain operative and in full force and effect without
any time limitation, except as any such other covenant will be limited in
duration by the express terms hereof.  Any claim asserted under or in respect
of this Agreement must be made by written notice (the "WRITTEN NOTICE")
containing specific details of the claim, including a reasonable estimate (on a
without prejudice basis) by the party asserting the claim of the amount of such
claim.

11.2     Indemnity by Seller.  Seller agrees to indemnify and hold harmless
Lafarge Canada against any Liabilities suffered or incurred by Lafarge Canada,
its successors or assigns resulting from:

         (a)     any breach by Seller or Lafarge S.A. of any covenants,
undertakings or agreements of Seller or Lafarge S.A. contained in this
Agreement;





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                                                   SIGNATURE COPY - JUNE 3, 1998


         (b)     any inaccuracy in or breach of any of the representations or
warranties made by Seller or Lafarge S.A.  in this Agreement;

         (c)     any Liabilities relating to non-compliance with the provisions
of the Bulk Sales Act (Ontario);

         (d)     any Liabilities suffered or incurred by Asset Acquiror, Share
Acquiror or Lafarge Canada in respect of any Excluded Liabilities (which
Excluded Liabilities, for greater certainty, include without limitation any
Liabilities to the extent arising from any debts, liabilities and obligations
(whether absolute, contingent, accrued or otherwise) of the Seller relating to
the Lime Business), except that this Section 11.2(d) shall not apply to those
Excluded Liabilities that constitute debts, liabilities or obligations of the
types described in Section 11.2(e) with respect to which any claim asserted
shall be addressed under Sections 11.2(e) and 11.3(d), as the case may be, and
shall be subject to the thresholds and apportionments of liability provided
under Sections 11.2(e), 11.3(d) and 11.4(a);

         (e)     subject to Section 11.3(d), any Liabilities to the extent
arising from any debts, liabilities or obligations (whether absolute,
contingent, accrued or otherwise) of the Seller relating to the Aggregate
Business and to any time on or prior to the Closing which are not (i) included
in the Financial Statements or the Working Capital Amount (ii) disclosed in the
Schedules 5.16 and 1.1(ff)(x) hereto or otherwise under Sections 7.17(d),(e)
and(f) and 7.20(a) and (b)(x) as being liabilities and obligations to be
assumed by Asset Acquiror and/or Lafarge Canada in accordance with their
respective terms (iii) known to the Share Acquiror or Lafarge Canada as of the
Closing, or (iv) incurred by the Seller in the ordinary course of business
consistent with past business practice since December 31, 1997 as permitted by
this Agreement; provided, however, that the Seller shall not be obligated to
indemnify or hold harmless the Share Acquiror or Lafarge Canada for any claim
under this section 11.2(e) unless (i) the Liabilities from such claim exceed
$100,000, or (ii) the aggregate Liabilities of all claims under this Section
11.2(e) and under Section 11.2(f) exceeds, in the aggregate, an amount equal to
(x) $1,000,000 less (y) the aggregate amount of Liabilities with respect to
claims that could be made under sections 9.2(f) and 9.2(g) of the United States
Stock Purchase Agreement but for the application of the $1,000,000 provision
therein;





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                                                   SIGNATURE COPY - JUNE 3, 1998


         (f)     any Liabilities not included in either the Financial
Statements or the Working Capital Amount to the extent arising from the
following, whether or not disclosed by Seller to Lafarge Canada in the
Schedules hereto or otherwise under this Agreement and whether or not Seller,
and/or Lafarge Canada had any actual knowledge of such Liabilities:  (i) the
release, discharge, or disposal of any Hazardous Materials (or allegations of
same) prior to the Closing Date (A) on or from the Real Properties or (B) on or
from any other property where Hazardous Material are or were (or are or were
alleged to be) released, discharged or disposed of in connection with the
operation of the business of the Seller, whether or not, in any case, such
release, discharge or disposal was in compliance with Environmental Law; (ii)
the violation of any Environmental Law prior to the Closing Date (or allegation
of same) by Seller or any other Person in connection with the Real Properties;
or (iii) any Environmental Claim against any Person whose liability for such
Environmental Claim Seller or any Affiliate of Seller has, in connection with
the Real Properties or any real property previously owned by the Seller,
assumed or retained either contractually or by operation of law prior to the
Closing Date; provided, however, that Seller shall not be obligated to
indemnify or hold harmless Lafarge Canada for any claim under this Section
11.2(f) unless (i) the Liabilities from such claim exceed $100,000 or (ii) the
aggregate Liabilities of all claims under Section 11.2(e) and this Section
11.2(f) exceeds an amount equal to (x) $1,000,000 less (y) the aggregate amount
of Liabilities will respect to claims that could be made under Sections 9.2(f)
and 9.2(g) of the United States Stock Purchase Agreement but for the
application of the $1,000,000 provision therein.

11.3     Indemnity by Lafarge Canada.  Lafarge Canada agrees to indemnify and
hold harmless Seller against any Liabilities suffered or incurred by Seller
resulting from:

         (a)     any breach by Lafarge Canada, Share Acquiror or Asset Acquiror
of any of the respective covenants, undertakings or agreements contained in
this Agreement; or

         (b)     any inaccuracy in or breach of any of the representations or
warranties made by either of Lafarge Canada or Share Acquiror in this
Agreement; or

         (c)     any Liabilities suffered or incurred by Seller in respect of
any Assumed Liability; or

         (d)     any Liabilities to the extent arising from any debts,
liabilities or obligations (whether absolute, contingent, accrued or otherwise)
of the Seller relating to the Aggregate Business and to





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                                                   SIGNATURE COPY - JUNE 3, 1998


any time on or prior to the Closing which are not (i) included in the Financial
Statements or the Working Capital Amount (ii) disclosed in the Schedules 5.16
and 1.1(ff)(x) hereto or otherwise under Sections 7.17(d),(e) and(f) and
7.20(a) and (b)(x) as being liabilities and obligations to be assumed by Asset
Acquiror and/or Lafarge Canada in accordance with their respective terms (iii)
known to the Share Acquiror or Lafarge Canada as of the Closing, or (iv)
incurred by the Seller in the ordinary course of business consistent with past
business practice since December 31, 1997 as permitted by this Agreement;
provided, however, that the liabilities and obligations of Lafarge Canada under
this Section 11.3(d) shall be limited to one-half of the amount of any
Liabilities less than $20,000,000 suffered or incurred by Seller arising or
resulting from the matters described in Section 11.3(d), it being understood
that Seller shall bear responsibility for one-half of the first $20,000,000 of
Liabilities arising or resulting from the matters described in Section 11.3(d)
and all such Liabilities in excess of $20,000,000.  The Parties further confirm
and agree that Lafarge Canada's contribution and liabilities and obligations
under Sections 11.3(d) and 11.4(a), although independent, shall not exceed the
aggregate amount of $10,000,000.

11.4     Limitations.

         (a)     Notwithstanding anything to the contrary in this Agreement,
Seller shall not be required to indemnify Lafarge Canada or its successors or
assigns under this Article XI in respect of any claims under Sections 11.2(a),
11.2(b), 11.2(e) or 11.2(f), except to the extent of one-half of all
Liabilities less than $20,000,000 and to the extent of all Liabilities in
excess of $20,000,000, it being understood that Lafarge Canada shall bear
responsibility for one- half of the first $20,000,000 of such Liabilities.  The
parties understand and agree that the limitations of the immediately preceding
sentence shall not apply to Liabilities arising out of Sections 11.2(b) (to the
extent relating to the representations and warranties of Seller contained in
Sections 5.2, 5.3 (but only to the extent relating to title), 5.9(e)(iv), 5.12
(but only to the extent relating to title) and 5.33)), 11.2(c) or 11.2(d).  The
$20,000,000 amounts referenced in Sections 11.3(d) and 11.4(a) are intended to
be, and shall be, calculated using the aggregate of the Liabilities within the
scope of Sections 11.3(d) and 11.4(a) and the Liabilities within the scope of
Section 9.4(a) of the United States Stock Purchase Agreement.





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                                                   SIGNATURE COPY - JUNE 3, 1998


         (b)     The amount of any Liabilities shall be calculated net of any
resulting net tax benefit or net insurance recovery (including net of any
increase in insurance premiums which may arise therefrom) actually received by
the indemnified party on account of such Liabilities.

11.5     Exclusive Remedies.  From and after the Closing, the right of each
party hereto to indemnification under this Article XI with respect to any
Liabilities shall be its sole and exclusive remedy under or with respect to
this Agreement or the transactions contemplated hereby, and it shall not be
entitled to pursue, and hereby expressly waives to the fullest extent permitted
by Law, any and all rights that may otherwise be available either at law or in
equity with respect thereto.  Without limiting the generality of the foregoing,
each party hereto waives to the fullest extent permitted by Law any claim or
cause of action which it might otherwise assert, including, without limitation,
under the common law or federal or provincial securities, trade regulations or
other Laws, by reason of this Agreement or the transactions contemplated
hereby, except for claims and causes of action brought pursuant to this Article
XI.  In no event shall the parties hereto be entitled to rescind this
Agreement.

11.6     Arbitration. In the event of any dispute concerning this Agreement,
its effect or the transactions contemplated by it, such dispute shall be
settled by arbitration conducted in New York City, New York, before a panel of
three arbitrators in accordance with the then applicable provisions of the
American Arbitration Association ("AAA") using the rules of procedure of the
State of New York.  Each of Lafarge Canada and Seller will appoint one
arbitrator, and those two arbitrators will appoint a third arbitrator.  In the
event that the two arbitrators cannot agree on a third arbitrator within 10
days following the appointment of the second arbitrator, then the third
arbitrator shall be appointed by the AAA in accordance with its then applicable
rules.  If either Lafarge Canada or Seller fails to appoint an arbitrator
within 45 days after written notice from one party to the other party detailing
the dispute, the arbitrator chosen by that other party shall act as the sole
arbitrator.  Punitive or exemplary damages will not be permitted under any
circumstances.  All determinations made by a majority of the arbitrators shall
be final, conclusive and binding on Lafarge Canada and Seller with costs paid
by the party who does not prevail in the arbitration.





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                                  ARTICLE XII

                                 MISCELLANEOUS

12.1     Entire Agreement.  This Agreement, including the Schedules hereto and
the Confidentiality Agreement constitute the entire agreement of the Parties
hereto with respect to the subject matter hereof and thereof and supersede all
prior agreements and undertakings, both written and oral, with respect to the
subject matter hereof and thereof.  It is agreed that none of the Parties has
entered into this Agreement in reliance upon any representation, warranty or
undertaking of the other Party which is not expressly set forth in this
Agreement.

12.2     Notices.  All notices, requests and other communications to any Party
hereunder shall be in writing (including facsimile) and signed by or on behalf
of the Party giving it and shall be given by personal delivery, certified or
registered mail or telecopy,

         if to Seller or Lafarge S.A., to:

         Lafarge S.A.
         61, rue des Belles Feuilles
         B.P.40, 75782 PARIS, CEDEX 16
         FRANCE
         Attention:  Directeur des Affaires Juridiques
         Telecopy:  (33-1) 44-34-11-48

         with copies to:

         Jones, Day, Reavis & Pogue
         3500 Sun Trust Plaza, 303 Peachtree Street, N.E.
         ATLANTA, GA  30308-3242
         Attention:  William S. Paddock
         Telecopy:  (404) 581-8330

         and to:

         Miller Thomson
         2500-20 Queen Street West
         TORONTO, ON M5H 3S1
         Attention: Michael J. Pace
         Telecopy: (416) 595-8695





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                                                   SIGNATURE COPY - JUNE 3, 1998


         if to Asset Acquiror, Share Acquiror or Lafarge Canada to:

         Lafarge Canada Inc.
         606 Cathcart
         MONTREAL, PQ H3B 1L7
         Attention:Alain Fredette, Director Legal Services and Secretary
         Telecopy:  (514) 861-1123

         with a copy to:

         McCarthy Tetrault
         Toronto-Dominion Bank Tower
         Suite 4700
         TORONTO, ON M5K 1E6
         Attention: W. Iain Scott
         Telecopy: (416) 868-0673

or such other address or facsimile number as such Party may hereafter specify
for the purpose by notice to the other parties hereto.  Each such notice,
request or other communication shall be effective (i) if given by facsimile
transmission, three hours after the time of dispatch to the facsimile number
specified in this Section 12.2 provided the appropriate confirmation is
received and provided that the time of receipt is during normal business hours
on a Business Day at the place of receipt; or (ii) if given by certified or
registered mail, on the fifth Business Day after the date of dispatch; or
(iii) if given by any other means allowed under this Section 12.2, 24 hours
after being sent to the address specified in this Section 12.2 if such 24 hour
period ends on a Business Day at the place of receipt, or if not, on the next
following Business Day.

12.3     Amendments; No Waivers.

                 (a)      Any provision of this Agreement may be amended or
waived prior to the Closing Date if, and only if, such amendment or waiver is
in writing and signed, in the case of an amendment, by the Parties hereto or in
the case of a waiver, by the Party against whom the waiver is to be effective.

                 (b)      No failure or delay by any Party in exercising any
right, power or privilege hereunder shall operate as a waiver thereof nor shall
any single or partial exercise thereof preclude any other or further exercise
thereof or the exercise of any other right, power or privilege.





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                                                   SIGNATURE COPY - JUNE 3, 1998


12.4     Expenses.  Except as otherwise provided herein, all costs and expenses
incurred in connection with this Agreement shall be paid by the Party incurring
such cost or expense.

12.5     Successors and Assigns.

                 (a)      The provisions of this Agreement shall be binding
upon and inure to the benefit of the Parties hereto and their respective
successors and assigns.  No Party may assign, delegate or otherwise transfer
any of its rights or obligations under this Agreement without the consent of
the other Parties hereto.

                 (b)      Notwithstanding anything contained in this Agreement
to the contrary, nothing in this Agreement, expressed or implied, is intended
to confer on any Person other than the Parties hereto or their respective
successors and permitted assigns, any rights, remedies obligations or
liabilities under or by reason of this Agreement.

12.6     Certain Interpretive Matters.

                 (a)      Unless the context otherwise requires, (i) all
references in this Agreement to Sections, Articles or Schedules are to
Sections, Articles or Schedules of or to this Agreement, (ii) each term defined
in this Agreement has the meaning ascribed to it,  (iii) words in the singular
include the plural and vice versa, (iv) unless otherwise expressly provided,
all references to "$" or dollar amounts will be to lawful currency of the
United States, (v) the Schedules referenced in this Agreement are incorporated
in this Agreement as of the date of its execution and constitute an integral
part hereof, (vi) no investigation by the Parties hereto made heretofore or
hereafter shall affect the representations and warranties of the Parties which
are contained herein, and each such representation and warranty shall survive
such investigation.

                 (b)      Titles and headings to Articles and Sections herein
are inserted for convenience of reference only, and are not intended to be a
part of or to affect the meaning or interpretation of this Agreement.  No
provision of this Agreement will be interpreted in favor of, or against, any of
the Parties hereto by reason of the extent to which any such Party or its
counsel participated in the drafting thereof or by reason of the extent to
which any such provision is inconsistent with any prior draft hereof or
thereof.

12.7     Governing Law.  This Agreement shall be construed in accordance with
and governed by the internal substantive laws of the Province of Ontario and
the applicable laws of Canada regardless





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                                                   SIGNATURE COPY - JUNE 3, 1998


of the laws that might otherwise govern under principles of conflict of laws
applicable thereto.  Subject to Section 11.6, each of the Parties hereto agree
that the Courts of Ontario are to have nonexclusive jurisdiction to settle any
disputes which may arise in connection with this Agreement.

12.8     Counterparts; Effectiveness.  This Agreement may be signed in any
number of counterparts, each of which shall be an original, with the same
effect as if the signatures thereto and hereto were upon the same instrument.
This Agreement shall become effective when each Party hereto shall have
received counterparts hereof signed by all of the other Parties hereto.

12.9     Confidentiality.  Each of the Parties hereto agree to maintain in
strict confidence any and all information each party learns or discovers about
the other or its respective Affiliates during the course of the negotiation,
execution and delivery of this Agreement and agrees to abide by the terms and
conditions set forth in the Confidentiality Agreement.  This Section 12.9 shall
not apply to any information that is, or could reasonably be, learned or
discovered through any independent source that is not obligated to maintain
such information as confidential.

12.10    Severability.  If any term, provision, covenant or restriction of this
Agreement is determined by a Governmental Entity to be invalid, void or
unenforceable, the remainder of the terms, provisions, covenants and
restrictions of this Agreement will remain in full force and effect and will in
no way be affected, impaired or invalidated.

         IN WITNESS WHEREOF, the Parties hereto have caused this Agreement to
be duly executed by their respective authorized officers as of the day and year
first above written.

                                       REDLAND QUARRIES INC.


                                       By:                                    
                                          ------------------------------------
                                       Name:  Gary E. Dale
                                       Title: Vice-President, Finance



                                       3489264 CANADA INC.



                                       By:                                    
                                          ------------------------------------
                                       Name:  Gary E. Dale
                                       Title: President





                                       77
<PAGE>   85
                                                   SIGNATURE COPY - JUNE 3, 1998


                                       3489949 CANADA INC.



                                       By:                                    
                                          ------------------------------------
                                       Name:  Joseph B. Sherk
                                       Title: President

                         (signatures continued on page 78)


                                       LAFARGE CANADA INC.



                                       By:                                    
                                          ------------------------------------
                                       Name:  Joseph B. Sherk
                                       Title: Vice-President




                                       LAFARGE S.A.



                                       By:                                    
                                          ------------------------------------
                                       Name:  Jean-Pierre Cloiseau
                                       Title: Director, Finance





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