Document:

<PAGE>

                                                                     Exhibit 4.2

                               FIRST AMENDMENT TO

                      AMENDED AND RESTATED CREDIT AGREEMENT

     This FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT (this
"Amendment"), effective as of May 21, 2002, is entered into by and among U.S.
Concrete, Inc., a Delaware corporation, (the "Borrower"), the Guarantors
signatory hereto under the caption "Guarantors" (together with each other Person
who becomes a Guarantor, collectively, the "Guarantors"), the Lenders signatory
hereto under the caption "Lenders" (together with each other Person who becomes
a Lender, collectively, the "Lenders") and JPMorgan Chase Bank, formerly known
as The Chase Manhattan Bank, a New York banking corporation, as administrative
agent for the other Lenders (in such capacity, together with any other Person
who becomes the administrative agent, the "Administrative Agent"), Credit
Lyonnais New York Branch and First Union National Bank, as syndication agents,
and Branch Banking & Trust Company, as documentation agent.

                              PRELIMINARY STATEMENT

     WHEREAS, the Borrower, the Guarantors, the Lenders, the Administrative
Agent, the syndication agents and the documentation agent have entered into that
certain Amended and Restated Credit Agreement dated as of August 31, 2001 (the
"Credit Agreement") under the terms of which the Lenders agreed to make
Revolving Credit Loans to the Borrower in an amount not exceeding
$200,000,000.00; and

     WHEREAS, the Borrower has requested the Lenders and the Administrative
Agent to amend certain terms of the Credit Agreement; and

     WHEREAS, the Lenders and the Administrative Agent have agreed to do so to
the extent reflected in this Amendment, provided that each of the Borrower and
the Guarantors ratifies and confirms all of its respective obligations under the
Credit Agreement and the Loan Documents.

     NOW, THEREFORE, in consideration of the premises and for other good and
valuable consideration and the mutual benefits, covenants and agreements herein
expressed, the receipt and sufficiency of which are hereby acknowledged, the
parties hereby agree as follows:

     1. Defined Terms. All capitalized terms used in this Amendment and not
otherwise defined herein shall have the meanings ascribed to such terms in the
Credit Agreement.

     2. Amendment to Section 1.1.

          (a) The definition of "EBITDA" in Section 1.1 of the Credit Agreement
     is hereby amended to add the following at the end of such definition:

                                       Page 1

<PAGE>

          "Notwithstanding anything herein to the contrary, for the purposes of
          calculating EBITDA, impairment to goodwill calculated in accordance
          with SFAS No. 142, Goodwill and Other Intangible Assets, shall be
          disregarded."

          (b) The definition of "Significant Subsidiary" in Section 1.1 of the
     Credit Agreement is hereby amended to add the following clause after the
     phrase "book value" in both places that it appears:

          ", excluding any adjustment, charge to net income or other charge or
          write-off calculated in accordance with SFAS No. 142, Goodwill and
          Other Intangible Assets,"

     3. Amendment to Section 6.9. Section 6.9 of the Credit Agreement is hereby
amended by adding the following at the end thereof:

          "For the purposes of calculating net worth, after September 30, 2001,
          impairments to goodwill calculated in accordance with SFAS No. 142,
          Goodwill and Other Intangible Assets, shall be disregarded."

     4. Amendment to Section 6.15. Section 6.15 of the Credit Agreement is
hereby amended by adding the following to the end thereof:

          "Notwithstanding the foregoing or any other provision of the Loan
          Documents, the Borrower may enter into such an agreement with respect
          to the real property located at 150 South Linden Avenue in San
          Francisco, California for a lease term not to exceed five (5) years
          (with an option to extend up to an additional five (5) years) and a
          rental rate not to exceed $250,000 per year (plus periodic adjustments
          customary for the related market), and on such other terms and
          conditions as approved by the Administrative Agent. Borrower shall
          submit all documentation evidencing such agreement for approval by the
          Administrative Agent prior to execution thereof."

     5. Amendment to Schedule 2.1. Schedule 2.1 of the Credit Agreement is
hereby deleted in its entirety and replaced with Schedule 2.1 attached hereto.

     6. Ratification. Each of the Borrower, as to itself and each Guarantor, and
each Guarantor, as to itself, hereby ratifies all of its respective obligations
under the Credit Agreement (including the Guaranty contained in Article X
thereof) and each of the Loan Documents to which it is a party, and agrees and
acknowledges that the Credit Agreement and each of the Loan Documents to which
it is a party remains in full force and effect and shall continue in full force
and effect as amended and modified by this Amendment. Except as amended or
modified by this Amendment, nothing in this Amendment extinguishes, novates or
releases any right, claim, lien,

                                       Page 2

<PAGE>

security interest or entitlement of any of the Lenders or the Administrative
Agent created by or contained in any of such documents nor is the Borrower or
any Guarantor released from any covenant, warranty or obligation created by or
contained therein or herein.

     7. Representations and Warranties. Each of the Borrower, as to itself and
each Guarantor, and each Guarantor, as to itself, hereby represents and warrants
to the Administrative Agent and the Lenders that (a) this Amendment has been
duly executed and delivered on behalf of the Borrower and such Guarantor, (b)
this Amendment constitutes a valid and legally binding agreement enforceable
against the Borrower or such Guarantor, as the case may be, in accordance with
its terms, subject to applicable bankruptcy, insolvency, fraudulent transfer,
reorganization, moratorium or other laws affecting creditors' rights generally
and subject to general principles of equity, regardless of whether considered in
a proceeding in equity or at law, (c) the representations and warranties
contained in the Credit Agreement and the Loan Documents shall be true and
correct on and as of the date of each Borrowing and the date of issuance,
amendment, renewal or extension of each Letter of Credit, as applicable, except
to the extent such representations and warranties relate to a prior date or,
after prior notice to the Administrative Agent, are untrue or incorrect as a
result of transactions permitted by the Loan Documents, (d) no Default exists
under the Credit Agreement or under any other Loan Document and (e) the
execution, delivery and performance of this Amendment has been duly authorized
by the Borrower and each Guarantor.

     8. Conditions to Effectiveness. This Amendment shall be effective upon (i)
the execution and delivery hereof by the Borrower, each Guarantor and Lenders
constituting the Required Lenders to the Administrative Agent and receipt by the
Administrative Agent of this Amendment.

     9. Counterparts. This Amendment may be signed in any number of
counterparts, which may be delivered in original or facsimile form each of which
shall be construed as an original, but all of which together shall constitute
one and the same instrument.

     10. Governing Law. This Amendment, the Credit Agreement, all Notes, the
other Loan Documents and all other documents executed in connection herewith
shall be deemed to be contracts and agreements under the laws of the State of
Texas and of the United States of America and for all purposes shall be
construed in accordance with, and governed by, the laws of Texas and of the
United States.

     11. Final Agreement of the Parties. THIS AMENDMENT AND THE CREDIT AGREEMENT
AND THE OTHER LOAN DOCUMENTS REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES
AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT
ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN
THE PARTIES.

                     [Remainder of Page Intentionally Blank]

                                       Page 3

<PAGE>

         IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
executed by their respective officers or other authorized representatives
thereunto duly authorized as of the date first above written.

                                  Borrower:

                                  U.S. CONCRETE

                                  By: /s/ Michael W. Harlan
                                      ------------------------------------------
                                      Michael W. Harlan
                                      Senior Vice President

                                       Page 4

<PAGE>

                                  Guarantors:

                                  AFTM Corporation, a Michigan corporation
                                  American Concrete Products, Inc., a California
                                    corporation
                                  Atlas-Tuck Concrete, Inc., an Oklahoma
                                    corporation
                                  Beall Concrete Enterprises, Ltd., a Texas
                                    limited partnership
                                  Beall Industries, Inc., a Texas corporation
                                  Beall Management, Inc., a Texas corporation
                                  Central Concrete Supply Co., Inc., a
                                    California corporation
                                  Central Precast Concrete, Inc., a California
                                    corporation
                                  Concrete XX Acquisition, Inc., a Delaware
                                    corporation
                                  Cornillie Fuel & Supply, Inc., a Michigan
                                    corporation
                                  Cornillie Leasing, Inc., a Michigan
                                    corporation
                                  DYNA, Inc., a Delaware corporation
                                  E.B. Metzen, Inc., a Michigan corporation
                                  Eastern Concrete Materials, Inc., a New Jersey
                                    corporation
                                  Fendt Transit Mix, Inc., a Michigan
                                    corporation
                                  Hunter Equipment Company, a Michigan
                                    corporation
                                  Ready Mix Concrete Company of Knoxville, a
                                    Delaware corporation
                                  San Diego Precast Concrete, Inc., a Delaware
                                    corporation
                                  Sierra Precast, Inc., a California corporation
                                  Smith Pre-Cast, Inc., a Delaware corporation
                                  Superior Concrete Materials, Inc. (f/k/a
                                    Opportunity Concrete Corporation, a
                                    District of Columbia corporation)
                                  USC Atlantic, Inc., a Delaware corporation
                                  USC GP, Inc., a Delaware corporation
                                  USC Management Co., LP, a Texas limited
                                    partnership
                                  USC Midsouth, Inc., a Delaware corporation
                                  USC Michigan, Inc., a Delaware corporation

                                  By: /s/ Michael W. Harlan
                                      ------------------------------------------
                                      Michael W. Harlan, Vice President

                                       Page 5

<PAGE>

                                  Carrier Excavation and Foundation Company, a
                                    Delaware corporation
                                  Premix Concrete Corp., a Delaware corporation
                                  Superior Redi-Mix, Inc., a Michigan
                                    corporation

                                  By: /s/ Charles W. Sommer
                                      ------------------------------------------
                                      Charles W. Sommer
                                      Vice President

                                  B.W.B., Inc. of Michigan, a Delaware
                                    corporation
                                  Central Concrete Corp., a Delaware corporation
                                  Olive Branch Ready Mix, Inc., a Delaware
                                    corporation
                                  Superior Materials Company, Inc., a Delaware
                                    corporation

                                  By: /s/ Donald Wayne
                                      ------------------------------------------
                                      Donald Wayne
                                      Vice President

                                  Wyoming Concrete Industries, Inc., a Delaware
                                    corporation

                                  By: /s/ Eugene P. Martineau
                                      ------------------------------------------
                                      Eugene P. Martineau
                                      Vice President

                                       Page 6

<PAGE>

                                  Administrative Agent/Lender:

                                  JPMORGAN CHASE BANK, formerly known as
                                    The Chase Manhattan Bank

                                  By:    /s/ Michael D. Pickerd
                                         ---------------------------------------
                                  Name:  Michael D. Pickerd
                                         ---------------------------------------
                                  Title: Senior Vice President
                                         ---------------------------------------

                                       Page 7

<PAGE>

                                  Syndication Agent/Lender:

                                  CREDIT LYONNAIS NEW YORK BRANCH

                                  By:    /s/ Attila Koc
                                         ---------------------------------------
                                  Name:  Attila Koc
                                         ---------------------------------------
                                  Title: Senior Vice President
                                         ---------------------------------------

                                       Page 8

<PAGE>

                                  Syndication Agent/Lender:

                                  FIRST UNION NATIONAL BANK

                                  By:    /s/ David L. Driggers
                                         ---------------------------------------
                                  Name:  David L. Driggers
                                         ---------------------------------------
                                  Title: Managing Director
                                         ---------------------------------------

                                       Page 9

<PAGE>

                                  Documentation Agent/Lender:

                                  BRANCH BANKING & TRUST COMPANY

                                  By:    /s/ Cory Boyte
                                         ---------------------------------------
                                  Name:  Cory Boyte
                                         ---------------------------------------
                                  Title: Senior Vice President
                                         ---------------------------------------

                                       Page 10

<PAGE>

                                  Lender:

                                  BANK OF AMERICA, N.A.

                                  By:    /s/ Elizabeth Jennings
                                         ---------------------------------------
                                  Name:  Elizabeth Jennings
                                         ---------------------------------------
                                  Title: Assistant Vice President
                                         ---------------------------------------

                                       Page 11

<PAGE>

                                  Lender:

                                  BANK ONE, N.A.

                                  By: /s/ Kandis A. Jaffrey
                                      ------------------------------------------
                                      Kandis A. Jaffrey, Director

                                       Page 12

<PAGE>

                                  Lender:

                                  THE BANK OF NOVA SCOTIA

                                  By:    /s/ N. Bell
                                         ---------------------------------------
                                  Name:  N. Bell
                                         ---------------------------------------
                                  Title: Senior Manager
                                         ---------------------------------------

                                       Page 13

<PAGE>

                                  Co-Managing Agent/Lender:

                                  FIRSTAR BANK

                                  By:    /s/ Joseph L. Sooter, Jr.
                                         ---------------------------------------
                                  Name:  Joseph L. Sooter, Jr.
                                         ---------------------------------------
                                  Title: Vice President
                                         ---------------------------------------

                                       Page 14

<PAGE>

                                  Lender:

                                  COMERICA BANK

                                  By:    /s/ William S. Rogers
                                         ---------------------------------------
                                  Name:  William S. Rogers
                                         ---------------------------------------
                                  Title: Vice President
                                         ---------------------------------------

                                       Page 15<PAGE>

                                                                     Exhibit 4.3

                              NEW LENDER ACCEPTANCE

     This New Lender Acceptance dated as of June 12, 2002 (this "Agreement") is
by and among (i) U.S. Concrete, Inc. ("Borrower"), (ii) JPMorgan Chase Bank,
formerly known as The Chase Manhattan Bank, in its capacity as administrative
agent (the "Administrative Agent") and Issuing Bank under the Amended and
Restated Credit Agreement dated as of August 31, 2001 (as the same may be
amended or otherwise modified from time to time, the "Credit Agreement";
capitalized terms that are defined in the Credit Agreement and not defined
herein are used herein as therein defined) among Borrower, the Lenders party
thereto, Credit Lyonnais New York Branch and First Union National Bank, as
Syndication Agents, and Branch Banking & Trust Company as Documentation Agent,
and the Administrative Agent, and (iii) Guaranty Bank ("New Lender").

                             Preliminary Statements

     Pursuant to Section 2.20 of the Credit Agreement, Borrower has the right,
subject to the terms and conditions thereof, to effectuate from time to time an
increase in the total Commitments under the Credit Agreement by adding to the
Credit Agreement one or more banks or other financial institutions as a Lender
thereunder.

     Accordingly, the parties hereto agree as follows:

     SECTION 1. Addition of New Lender. Pursuant to Section 2.20 of the Credit
Agreement, the New Lender is hereby added to the Credit Agreement as a Lender
with a Commitment of $12,000,000. The New Lender specifies as its Domestic
Lending Office and Eurodollar Lending Office the following:

                  Domestic Lending Office:  Guaranty Bank
                  Address:                  333 Clay Street
                                            Houston, Texas  77002
                  Attention:                Scott L. Brewer, Vice President
                  Telephone:                (713) 890-8859
                  Telecopy:                 (713) 759-0765

                  Eurodollar Lending Office:
                  Address:

                  Attention:
                  Telephone:
                  Telecopy:

     SECTION 2. New Note. The Company agrees to promptly execute and deliver to
the New Lender a Note ("New Note") in a principal amount equal to its
Commitment.

                                       -1-

<PAGE>

     SECTION 3. Consent. The Administrative Agent, the Issuing Bank and Borrower
hereby consent to the increase in the Commitments and addition of the New Lender
effectuated hereby.

     SECTION 4. Governing Law. This Agreement shall be governed by, and
construed in accordance with, the laws of the State of Texas.

     SECTION 5. Execution in Counterparts. This Agreement may be executed in any
number of counterparts and by different parties hereto in separate counterparts,
each of which when so executed shall be deemed to be an original and all of
which taken together shall constitute one and the same agreement.

     SECTION 6. Lender Credit Decision. The New Lender acknowledges that it has,
independently and without reliance upon the Administrative Agent or any other
Lender and based on the financial statements referred to in Section 3.1(f) of
the Credit Agreement and such other documents and information as it has deemed
appropriate, made its own credit analysis and decision to enter into this
Agreement and to agree to the various matters set forth herein. The New Lender
also acknowledges that it will, independently and without reliance upon the
Administrative Agent or any other Lender and based on such documents and
information as it shall deem appropriate at the time, continue to make its own
credit decisions in taking or not taking action under the Credit Agreement.

     SECTION 7. Representation and Warranties of Borrower. The Company
represents and warrants as follows:

          (a) The execution, delivery and performance by Borrower of this
     Agreement and the New Note are within Borrower's corporate powers, have
     been duly authorized by all necessary corporate action, and do not
     contravene (i) Borrower's restated certificate of incorporation or by-laws
     or (ii) any indenture, loan agreement or other similar agreement or
     instrument binding on the Borrower.

          (b) No authorization, consent or approval of any governmental body or
     agency is required for the valid execution, delivery and performance of
     this Agreement by Borrower or for the valid execution, issuance, delivery
     and performance of the New Note by Borrower.

          (c) This Agreement constitutes a valid and binding agreement of
     Borrower, enforceable against Borrower in accordance with its terms,
     subject to applicable bankruptcy, insolvency or similar laws affecting
     creditors' rights generally and equitable principles of general
     applicability. The New Note, when executed, issued and delivered hereunder
     for value received, will constitute a valid and binding obligation of
     Borrower, enforceable in accordance with its terms, except as (i) the
     enforceability thereof may be limited by bankruptcy, insolvency or similar
     laws affecting creditors' rights generally and (ii) rights of acceleration
     and the availability of equitable remedies may be limited by equitable
     principles of general applicability.

          (d) The aggregate amount of the Commitments under the Credit
     Agreement, including any increases pursuant to Section 2.20 thereof, does
     not exceed $200,000,000.

                                       -2-

<PAGE>

     (e) No event has occurred and is continuing which constitutes an Event of
Default.

     (f) Prior to the increase in Commitment pursuant to this Agreement,
Borrower has offered the Lenders the right to participate in such increase by
increasing their respective Commitments.

     SECTION 8. Expenses. The Company agrees to pay on demand all costs and
reasonable expenses of the Administrative Agent in connection with the
preparation, negotiation, execution and delivery of this Agreement and the New
Note, including, without limitation, the reasonable fees and out-of-pocket
expenses of counsel for the Administrative Agent with respect thereto.

     SECTION 9. Effectiveness. When, and only when, the Administrative Agent
shall have received counterparts of, or telecopied signature pages of, this
Agreement executed by Borrower, the Administrative Agent and the New Lender,
this Agreement shall become effective as of the date first written above.

                                       -3-

<PAGE>

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed by their respective officers thereunto duly authorized, as of the date
first above written.

                                 U.S. CONCRETE, INC.

                                 By:      /s/ Michael W. Harlan
                                          --------------------------------------
                                 Name:    Michael W. Harlan
                                          --------------------------------------
                                 Title:   Senior Vice President
                                          --------------------------------------

                                       -4-

<PAGE>

                                 JPMORGAN CHASE BANK, formerly known as
                                 THE CHASE MANHATTAN BANK,
                                 as Administrative Agent and Issuing Bank

                                 By:      /s/ Michael D. Pickerd
                                          --------------------------------------
                                 Name:    Michael D. Pickerd
                                          --------------------------------------
                                 Title:   Senior Vice President
                                          --------------------------------------

                                       -5-

<PAGE>

                                 GUARANTY BANK

                                 By:      /s/ Scott Brewer
                                          --------------------------------------
                                 Name:    Scott Brewer
                                          --------------------------------------
                                 Title:   Vice President
                                          --------------------------------------

                                       -6-

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00042-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00042-of-00352.parquet"}]]