July 22, 1994

Contract #TW0592

SPECIAL SPECIFICATION

SECTION 03300-S

[CAST-IN-PLACE CONCRETE]{.underline}

[PART 1 - GENERAL]{.underline}

1.01 Description Of Work 2

1.02 References 2

1.03 Submittals 3

1.04 Quality Assurance 3

PART 2 - PRODUCTS

2.01 Form Materials 4

2.02 Reinforcing Materials 5

2.03 Concrete Materials 5

2.04 Related Materials 6

2.05 Concrete Mix Design 6

PART 3 - EXECUTION

3.01 Forms 7

3.02 Placing Reinforcement 9

3.03 Joints 10

3.04 Preparations For Placing Concrete 11

3.05 Placing Concrete 11

3.06 Concrete Finishing 13

3.07 Concrete Curing 14

3.08 Removal Of Forms 15

3.09 Reuse Of Forms 16

3.10 Concrete Surface Repairs 16

3.11 Concrete Truck Discharge 16

SPECIAL SPECIFICATION

SECTION 03300-S

[CAST-IN-PLACE CONCRETE]{.underline}

# PART 1 - GENERAL

## 1.01 [DESCRIPTION OF WORK]{.underline}

A. [Section Includes]{.underline}: Cast-in-place concrete, including
formwork, reinforcing, mix design, placement procedures, and finishes.

B. [Related Sections]{.underline}: Refer to the following sections for
related work:

1\. Division 5, Section \"Structural Steel\".

2\. Division 2, Section \"Earthwork\".

3\. Division 3, Section \"Exposed Aggregate Concrete Slabs\".

## 1.02 [REFERENCES]{.underline}

A. [American Society for Testing and Materials (ASTM)]{.underline}

A82 Specification for Steel Wire, Plain, for Concrete Reinforcement

A185 Specification for Steel Welded Wire Fabric, Plain for Concrete
Reinforcement

A615 Specification for Deformed and Plain Billet - Steel Bars for
Concrete Reinforcement

C33 Specification for Concrete Aggregates

C94 Specification for Ready-Mixed Concrete

C150 Specification for Portland Cement

C260 Specification for Air-Entraining Admixtures for Concrete

C309 Specification for Liquid Membrane-Forming Compounds for Curing
Concrete

C494 Specification for Chemical Admixtures for Concrete

C618 Specification for Fly Ash and Raw or Calcined Natural Pozzolan for
Use as a Mineral Admixture in Portland Cement Concrete

C1107 Specification for Packaged Dry, Hydraulic-Cement Grout
(non-shrink)

C1116 Specification for Fiber-Reinforced Concrete and Shotcrete

D994 Specification for Preformed Expansion Joint Filler for Concrete

D1751 Specification for Preformed Expansion Joint Filler for Concrete
Paving and Structural Construction

B. [Corps of Engineers (CE)]{.underline}

CRD C621 Specification for Non shrink Grout

## 1.03 [SUBMITTALS]{.underline}

A. [General]{.underline}: Submit the following items in accordance with
the Conditions of Contract and Division 1, Section \"Descriptive
Submittals\".

B. [Product Data]{.underline}: Submit product data for the following
materials and items.

1\. Reinforcement

2\. Forming Accessories

3\. Admixtures

4\. Patching Compounds

5\. Hardener

6\. Joint Systems

7\. Curing Compounds

8\. Sealants

C. [Shop Drawings]{.underline}: Submit shop drawings, when indicated,
for fabrication, bending and placement of concrete reinforcement. Show
bar schedules, stirrup spacing, diagrams of bent bars and arrangement of
reinforcement including bar overlap. Include any special reinforcement
required for openings through concrete structures.

D. [Laboratory Test Reports]{.underline}: Submit concrete materials test
reports and mix design reports certifying that each material or item
complies with or exceeds the specified requirements.

## 1.04 [QUALITY ASSURANCE]{.underline}

A. [Codes and Standards]{.underline}: Comply with provisions of the
latest edition or revision of the following, except as otherwise
indicated:

1\. ACI 301 \"Specifications for Structural Concrete for Buildings\"

2\. ACI 302 \"Guide for Concrete Floor and Slab Construction\"

3\. ACI 304 \"Guide for Measuring, Mixing, Transporting and Placing
Concrete\"

4\. ACI 305 \"Hot Weather Concreting\"

5\. ACI 306 \"Cold Weather Concreting\"

6\. ACI 308 \"Standard Practice for Curing Concrete\"

7\. ACI 309 \"Standard Practice for Consolidation of Concrete\"

8\. ACI 315 \"Details and Detailing of Concrete Reinforcement\"

9\. ACI 318 \"Building Code Requirements for Reinforced Concrete\"

10\. ACI 347 \"Recommended Practice for Concrete Formwork\"

11\. CRSI \"Manual of Standard Practice\"

12\. SP-66 \"ACI Detailing Manual\"

B. [Materials and installed work]{.underline} may require testing and
retesting, as directed by the Sandia Delegated Representative (SDR), at
anytime during progress of work. Initial testing of materials will be at
Sandia National Laboratories\' (SNL) expense. Retesting of rejected
materials and installed work, shall be done at Contractor\'s expense.

Each concrete truck will be monitored at the site for concrete
temperature, revolution count, and time of mixing.

The first truck for each placement will be tested for slump and
percentage air. Each additional 30 cubic yards of concrete will be
tested. Additional testing may occur at anytime during progress of work.

Compression test cylinders will be made for each truck that has been
accepted for slump and air content.

# PART 2 - PRODUCTS

## 2.01 [FORM MATERIALS]{.underline}

A. [Forms shall be]{.underline} of metal, wood or fiberglass with
sufficient thickness to withstand pressure of newly-placed concrete
without bow or deflection. Forms for exposed surfaces shall be free of
holes, splits, surface voids, and other defects which can affect
finished concrete surface.

B. [Cylindrical Columns and Supports]{.underline}: Form round-section
members with paper or fiber tubes, constructed of laminated plies using
water-resistant adhesive with wax-impregnated exterior for weather and
moisture protection. Provide units with sufficient wall thickness to
resist loads imposed by wet concrete without deformation.

C. [Form Coatings]{.underline}: Provide commercial formulation
form-coating compounds that will not bond with, stain, nor adversely
affect concrete surfaces, and will not impair subsequent treatments of
concrete surfaces.

D. [Form Ties]{.underline}: Use factory-fabricated, adjustable-length,
removable or snapoff metal form ties, designed to prevent form
deflection, and to prevent spalling concrete surfaces upon removal.

l\. Unless otherwise indicated, provide ties so portion remaining within
concrete after removal is at least l/2\" (12.7 mm) inside concrete for
steel ties and l/4\" (6.35 mm) for wire ties.

2\. Unless otherwise shown, provide form ties which will not leave holes
larger than l\" (25.4 mm) diameter in concrete surface.

## 2.02 [REINFORCING MATERIALS]{.underline}

A. [Reinforcing Bars]{.underline}: ASTM A615, deformed.

1\. Provide Grade 40 bars No. 3 and 4 for stirrups and ties.

2\. Provide Grade 60 bars No. 3 to 18, except as otherwise noted.

B. [Welded steel wire fabric]{.underline}: ASTM A185.

Furnish in flat sheets, not rolls, unless rolls are acceptable to the
Sandia Delegated Representative.

C. [Cold-drawn steel wire]{.underline}: ASTM A82.

D. [Supports for Reinforcement]{.underline}: Provide supports for
reinforcement including bolsters, chairs, spacers and other devices for
spacing, supporting and fastening reinforcing bars and welded wire
fabric in place. Use wire bar type supports complying with CRSI
recommendations, unless otherwise indicated. Do not use wood, brick,
stone, broken block or pieces of concrete, etc.

2.03 [CONCRETE MATERIALS]{.underline}

A. [Portland Cement]{.underline}: ASTM C150 Types I-II and III unless
otherwise specified. All types of Portland Cement for paving and
sidewalks shall be \"low-alkali cement.\"

B. [Aggregates]{.underline}: ASTM C33

C. [Water]{.underline}: Potable

D. [Fly Ash]{.underline}: ASTM C618, Class F.

E. [Admixtures]{.underline}: All admixtures shall be specified in the
mix design.

1\. Air-Entraining Admixture: ASTM C260

2\. Water-Reducing Admixture: ASTM C494, Type A.

3\. High Range Water-Reducing Admixture (Super Plasticizer): ASTM C494,
Type F or Type G.

4\. Water-Reducing, Retarding Admixture: ASTM C494, Type D.

5\. Chloride-containing admixtures are not permitted.

## 2.04 [RELATED MATERIALS]{.underline}

A. [Expansion Joint Materials]{.underline}: Premolded strips of a
bituminous mastic composition conforming to ASTM D994.

B. [Non-Shrink Grout]{.underline}: ASTM C1107 (formerly referenced as CE
CRD C621), factory pre-mixed grout, non-metallic.

C. [Liquid Membrane-Forming Curing Compound]{.underline}: ASTM C309,
Type I or I-D, Class A.

D. [Chemical Hardener]{.underline}: Hardener shall be a colorless,
aqueous solution of zinc or magnesium fluosilicate. Approved proprietary
hardeners shall be delivered ready for use in the manufacturer\'s
original containers.

E. [Bonding Compound]{.underline}: Polyvinyl acetate, rewettable type.

## 2.05 [CONCRETE MIX DESIGN]{.underline}

A. [General]{.underline}

1\. Unless otherwise specified, the minimum strength of concrete shall
be 4000 psi (210.9 kgs-sq cm) at 28 days.

2\. Concrete mixtures shall produce the necessary workability in fresh
concrete and the desired strength.

3\. Unless otherwise approved or specified, all concrete shall be
\"Ready-Mixed\" in accordance with ASTM C94.

4\. The water-cement ratio selected shall be that required to produce a
28-day strength corresponding to an over designed mix which is supported
by sufficient experience data to assure that test results will fall
within the limits established in this specification. Unless otherwise
specified, the following proportions apply:

Strength Min. Cement Max. W/C Max. Water

[psi]{.underline} [Bag/C.Y]{.underline}. [Ratio]{.underline} [Gal./Bag
Cement]{.underline}

3000( 210.9 kgs-sq cm) 5.0 0.60 6.8

4000( 281.2 kgs-sq cm) 6.0 0.50 5.6

5\. Allowable Slump: [min-max (in.)]{.underline}

Massive section, pavement or slabs on ground 1-4 (25.4 mm-101.6 mm)

Slabs, beams, walls and columns 3-5 (76.2 mm-127 mm)

Concrete containing super plasticizer 3-8 (76.2 mm-203.2 mm)

B. [Aggregate]{.underline}: Aggregate Grading shall be as follows for
the different strengths of concrete.

1\. [Coarse Aggregate]{.underline}

Shall be as per ASTM C33, Table 2, Grading Requirements for Coarse
Aggregates.

2\. [Fine Aggregate]{.underline}

Shall be as per ASTM C33, Sieve Analysis, Fine Aggregate.

C. Admixtures

1\. Use water-reducing admixture or high range water-reducing admixture
(super plasticizer) in all concrete.

2\. Use air-entraining admixture in exterior exposed concrete unless
otherwise indicated. Use an air content of 3.5 to 6.5 percent.

3\. When an air-entraining admixture is used solely for increasing the
workability of the mix, use an air content of 3 to 5 percent.

4\. Fly Ash - Unless otherwise specified, a maximum of 9 pounds (4.08
kg) of fly ash per bag of cement will be permitted.

D. [High early strength concrete]{.underline} shall have a compressive
strength at 7 days equal to that specified for ordinary concrete at 28
days.

# PART 3 - EXECUTION

## 3.01 [FORMS]{.underline}

A. [Design, erect, support, brace and maintain]{.underline} formwork to
support vertical and lateral loads that might be applied until such
loads can be supported by concrete structure. Construct formwork so
concrete members and structures are of correct size, shape, alignment,
elevation and position. Provide for openings, keyways, chamfers, inserts
and other features required in work. Maintain formwork construction
tolerances, unless otherwise indicated:

1\. [Variation from Plumb]{.underline}:

a\. In the lines and surfaces of columns, piers, walls, and in arrises:

In any 10 ft (3.05 m) of length 1/4 in. (6.4 mm)

Maximum for the entire length 1 in. (25.4 mm)

b\. For exposed corner columns, control-joint grooves, and other
conspicuous lines:

In any 20 ft (6.10 m) length 1/4 in. (6.4 mm)

Maximum for the entire length 1/2 in. (12.7 mm)

2\. [Variation from the level]{.underline} or from the grades specified
in the contract drawings:

a\. In slab soffits, ceilings, beam soffits and in arrises, measured
before removal of supporting shores:

In any 10 ft (3.05 m) of length 1/4 in. (6.4 mm)

In any bay or in any 20 ft (6.10 m) length 3/8 in. (9.7 mm)

Maximum for the entire length 3/4 in. (19 mm)

b\. In exposed lintels, sills, parapets, horizontal grooves, and other
conspicuous lines:

In any bay or in 20 ft (6.10 m) length 1/4 in. (6.4 mm)

Maximum for the entire length 1/2 in. (12.7 mm)

3\. [Variation of the linear]{.underline} building lines from
established position in plan and related position of columns, walls, and
partitions:

In any bay 1/2 in. (12.7 mm)

In any 20 ft (6.10 m) of length 1/2 in. (12.7 mm)

Maximum for the entire length 1 in. (25.4 mm)

4\. [Variation in the sizes and location]{.underline} of sleeves, floor
openings,

and wall openings 1/4 in. (6.4 mm)

5\. [Variation in cross-sectional dimensions]{.underline} of columns and
beams and in the thickness of slabs and walls:

Minus 1/4 in. (6.4 mm)

Plus 1/2 in. (12.7 mm)

6\. [Footings]{.underline}\*:

a.. Variations in dimensions in plan:

Minus 1/2 in. (12.7 mm)

Plus 2 in.(50.8 mm)

b\. Misplacement or eccentricity:

> 2 percent of the footing width in
>
> the direction of misplacement but

not more than 2 in. (50.8 mm)

c\. Thickness:

Decrease in specified thickness\...\...\...\...\...\...\...5%

Increase in specified thickness\...\...\...\...\...No limit

7\. Variation in Steps:

a\. In a flight of stairs:

Rise +1/8 in. (+3.2 mm)

Tread +1/4 in. (+6.4 mm)

b\. In consecutive steps:

Rise. +1/16 in. (+1.5 mm)

Tread +1/8 in. (+3.2 mm)

\* Tolerances apply to concrete dimensions only.

B. [Design and fabricate formwork]{.underline} to be readily removable
without impact, shock or damage to cast-in-place concrete surfaces and
adjacent materials.

C. [Chamfer exposed corners and edges]{.underline} as indicated in the
drawings to produce uniform smooth lines and tight edge joints.

D. [All curb and combined curb and gutter]{.underline} shall be divided
into blocks or stones in lengths not to exceed 6 feet (1.83 m) long
using metal templates not less than 1/16 inch (1.5 mm) thick cut to the
same cross section as the curb or curb and gutter being constructed.
[Templates shall be securely attached to forms to prevent movement
during concrete placement.]{.underline}

E. [Provisions for Other Trades]{.underline}: Provide openings in
concrete formwork to accommodate work of other trades. Determine size
and location of openings, recesses and chases from trades providing such
items. Accurately place and securely support items built into forms.

## 3.02 [PLACING REINFORCEMENT]{.underline}

A. [Comply with CRSI\'s]{.underline} recommended practice for \"Placing
Reinforcing Bars\", for details and methods of reinforcement placement
and supports, and as herein specified. Field bending of grade 60 bars is
not permitted.

B. [Clean reinforcement]{.underline} of loose rust and mill scale,
earth, ice, oil, concrete splatter from previous pours, and other
materials which reduce or destroy bond with concrete.

C. [Accurately position, support and secure reinforcement]{.underline}
against displacement by formwork, construction, or concrete placement
operations. Locate and support reinforcing by metal chairs, runners,
bolsters, spacers, and hangers, as required.

D. [Install welded wire fabric of same gage]{.underline} in as long of
lengths as practicable. Lap adjoining pieces at least one full mesh and
lace splices with wire. Offset end laps of adjacent widths to prevent
continuous laps in either direction.

E. [Provide minimum cover for reinforcement]{.underline} of
cast-in-place concrete, unless otherwise indicated.

Concrete cast against and permanently exposed to earth 3 in. (76.2 mm)

Concrete exposed to earth or weather

#6 and larger 2 in. (50.8 mm)

#5 and smaller 1 1/2 in. (38.1 mm)

Concrete not exposed to weather or in contact with earth

Slabs, walls, joists 3/4 in. (19 mm)

Beams, columns 1 1/2 in. (50.8 mm)

## 3.03 [JOINTS]{.underline}

A. [Construction Joints]{.underline}

1\. Locate construction joints on slab floor, which are not shown on
drawings, and notify Sandia Delegated Representative for approval.

2\. Provide keyways at least 1-1/2\" (38.1 mm) deep in construction
joints in walls and between walls and footings; accepted preformed
keyways designed for this purpose may be used for slabs.

3\. Place construction joints perpendicular to the main reinforcement.
Continue reinforcement across construction joints unless otherwise noted
on drawings.

B. [Isolation Joints]{.underline}: Construct isolation joints in
slabs-on-ground at points of contact between slabs on ground and
foundations as shown on drawings. Unless otherwise indicated, install
90# felt paper between slab and vertical surface.

C. [Contraction (Control) Joints]{.underline}

1\. [Contraction Joints in Slabs-on-Ground]{.underline}: Construct
contraction joints in slabs-on-ground to form panels of patterns as
shown. Contraction joints in floor slabs shall be formed as shown on
drawings..

2\. [Walks]{.underline}: Contraction joints shall not exceed intervals
of 6 feet (1.828 m). Joints shall be made at regular intervals along the
line of the work. On straight work, the joints shall be parallel with
and at right angles to the line of the work; at curves the joints shall,
in general, be along lines concentric with and radial to the proportion
of the work in which they are placed. The markings shall be made with
jointer tools that will round the edges of the scoring lines to a radius
of 1/8 inch (3.2 mm), with a depth of not less than 1 1/4 inch (31.75
mm). The finished joint opening, exclusive of radii, shall not be wider
[than 1/8 inch (3.2 mm).]{.underline}

D. [Expansion Joints]{.underline}

1\. [Slabs-on-Ground]{.underline}: Expansion joint material shall be
placed around utility access openings within the slab, including clean
outs and utility valves, and between new concrete slab and adjacent
masonry. Joint material shall be 1/2 inch (12.7 mm) thick, premolded,
asphalt impregnated complying with ASTM D1751 and extend the full depth
of the concrete.

2\. [Curbs and Gutters]{.underline}: Construct 1/2 inch (12.7 mm) joints
in curbs and gutters at the end of all returns except where cross
gutters are being constructed. They shall be at the ends of the cross
gutter transitions and also along the line of work at regular intervals,
not to exceed 36 feet (10.97 m). Joints in gutter shall be continuous
with those in adjacent curb.

3\. [Walks]{.underline}: Place joints in walks, between walk and a
building or structure, in walk returns, and between the walk and the
back of the curb returns. Expansion joints shall be in accordance with
the expansion joint detail shown on the drawings.. Where sidewalk abutts
curb, joint filler strips between walk and curb shall be the full depth
of the walk with the top of the filler strip set flush with the top of
the curb. Transverse sidewalk joints shall not exceed 30 feet (9.14 m)
spacing. Joint material shall be 1/2 inch (12.7 mm) thick.

## 3.04 [PREPARATIONS FOR PLACING CONCRETE]{.underline}

A. [Water shall be removed]{.underline} from excavations. Wood chips,
shavings, and hardened concrete shall be removed from the forms before
any concrete is placed. All equipment shall be cleaned. Forms shall be
wetted, except in freezing weather, or oiled.

B. [The earth shall be]{.underline} uniformly moist when the concrete is
placed. The method of sprinkling shall not be such as to form mud or
pools of water. Watering the subgrade immediately prior to placing the
concrete is not sufficient to make the soil uniformly moist.

C. [Notify other crafts]{.underline} to permit installation of their
work. Coordinate the installation of joint materials and moisture
barriers with placement of forms and reinforcing steel.

## 3.05 [PLACING CONCRETE]{.underline}

A. [Field Inspection]{.underline}

1\. Concrete shall not be placed until forms and reinforcing steel have
been inspected and approved. SDR shall receive written notification of
the Contractor's request to place concrete no less than 24 hours before
placement is to occur.

2\. Ready-Mix concrete shall be placed within a specified delivery time:

Below 40°F (4.4° C) see cold weather placing

40°-85°F (4.4 - 29.4°C) 90 minutes

86°-90°F (30° - 32.2° C) 75 minutes

above 90°F (32.2°C) 60 minutes

Concrete exceeding delivery time may be rejected by the Sandia Delegated
Representative.

3\. Adding Water: No water shall be added after the initial introduction
of mixing water for the batch except, when on arrival at the job site,
the slump of the concrete is less than that specified, and the maximum
water/cement ratio for the mix has not been exceeded. Such additional
water shall be added to bring the slump within limits. The drum shall be
turned at least 30 additional revolutions at mixing speed. The Sandia
Delegated Representative shall be notified before adding any water.
Water shall not be added to the batch at any later time.

The contractor shall insure that the concrete strength meets
specifications and that the maximum amount of water as noted in the
CONCRETE MIX DESIGN is not exceeded. Comply with ASTM C 94.

B. [General]{.underline}: Comply with ACI 304, and as herein specified.
Deposit concrete continuously or in layers of such thickness that no
concrete will be placed on concrete which has hardened sufficiently to
cause the formation of seams or planes of weakness. If a section cannot
be placed continuously, provide construction joints as herein specified.
Deposit concrete as nearly as practicable to its final location to avoid
segregation.

C. [Placing Concrete in Forms]{.underline}

1\. Deposit concrete in forms in horizontal layers not deeper than 24\"
(609.6 mm) and in a manner to avoid inclined construction joints. Where
placement consists of several layers, place each layer while preceding
layer is still plastic to avoid cold joints.

2\. Consolidate placed concrete by high frequency mechanical vibrating
equipment, supplemented, as necessary, by hand-spading, rodding or
tamping. Use equipment and procedures for consolidation of concrete in
accordance with ACI 309.

3\. [Do not use vibrators to transport concrete inside
forms]{.underline}. Insert and withdraw vibrators vertically at
uniformly spaced locations not farther than visible effectiveness of
machine. Place vibrators to rapidly penetrate placed layer and at least
6\" (152.4 mm) into preceding layer. Do not insert vibrators into lower
layers of concrete that have begun to set. At each insertion limit
duration of vibration to time necessary to consolidate concrete and
complete embedment of reinforcement and other embedded items without
causing segregation of mix.

4\. Concrete shall not be allowed to free fall more than 5 feet (1.52 m)
unless confined by a closed chute, except that concrete being placed in
walls 10 inches (254 mm) or less in thickness may free fall a maximum of
8 feet (2.44 m).

D. [Placing Concrete Slabs]{.underline}

1\. Deposit and consolidate concrete slabs in a continuous operation,
within limits of construction joints, until the placing of a panel or
section is completed.

2\. Bring slab surfaces to correct level as above, and use bull floats
or darbies to smooth surface, free of humps or hollows. Do not use tools
(i.e., jitterbugs) that force the aggregate away from the surface.

3\. Maintain reinforcing in proper position during concrete placement
operations.

E. [Cold Weather Placing]{.underline}: Protect concrete work from
physical damage or reduced strength which could be caused by frost,
freezing actions, or low temperatures; comply with ACI 306 and these
specifications.

1\. Concrete shall be mixed and placed only when the temperature is at
least 40°F (22°C) and rising unless permission to pour is obtained from
the Sandia Delegated Representative.

2\. Do not use frozen materials or materials containing ice or snow. Do
not place concrete on frozen subgrade or on subgrade containing frozen
materials.

3\. Do not use calcium chloride, salt and other materials containing
antifreeze agents or chemical accelerators.

4\. When approval is obtained to place concrete at or below an
atmospheric temperature of 40°F (22°C), the water or aggregates, or
both, shall be heated, and suitable enclosures and heating devices shall
be provided. The mixed concrete shall have a temperature of at least
50°F (28°C) and not more than 90°F (50°C) at the time of placing.

The heating equipment or methods shall be capable of heating the water
and aggregates uniformly, and these materials shall not be heated to a
temperature exceeding 150°F (83°C).

5\. After any concrete is placed, the Contractor shall provide suitable
measures to maintain a concrete surface temperature of 40°F (22°C) or
above for a period of not less than 7 days.

F. [Hot Weather Placing]{.underline}: When hot weather conditions exist
that would seriously impair quality and strength of concrete, place
concrete in compliance with ACI 305 and as herein specified.

1\. Cool ingredients before mixing to maintain concrete temperature at
time of placement below 90°F (50°C).

2\. Cover reinforcing steel with water-soaked burlap when required to
ensure that steel temperature will not exceed the ambient air
temperature immediately before embedment in concrete.

3\. Wet forms thoroughly before placing concrete.

4\. Use water-reducing retarding admixture (Type D) when required by
high temperatures, low humidity, or other adverse placing conditions.

## 3.06 [CONCRETE FINISHING]{.underline}

A. [General]{.underline}

1\. Do not use tools (i.e., jitterbugs) that force the aggregate away
from the surface.

2\. Water shall not be sprayed or sprinkled onto a concrete surface to
aid in finishing.

3\. The finisher should avoid bringing more water than necessary to the
surface and avoid working the surface any more than necessary to obtain
the required finish.

B. [Slab Finishes]{.underline}

1\. Float Finish: Apply float finish to slabs for driveways, exterior
slabs, curbs and gutters and interior floor slabs receiving additional
covering.

After screeding, consolidating, and leveling concrete slabs, do not work
surface until ready for floating. Begin floating, using float blades or
float shoes only, when surface water has disappeared, when concrete has
stiffened sufficiently to permit operation of power-driven floats, or
both. Consolidate surface with power-driven floats or by hand-floating
if area is small. Slab surface tolerance shall have a specified F~F~ of
20 and F~L~ of 15 in accordance with ACI 302 and ACI 117.

2\. Trowel Finish: Apply trowel finish to interior exposed floors.

After floating, begin first trowel finish operation. Begin final
troweling when surface produces a ringing sound as trowel is moved over
surface. Consolidate concrete surface by final hand-troweling operation,
free of trowel marks, and uniform in texture and appearance. Slab
surface shall have a specified F~F~ of 20 and F~L~ of 15 in accordance
with ACI 302 and ACI 117.

3\. Light Broom: For sidewalks apply trowel finish as specified above.
Immediately follow with slightly scarifying surface by fine brooming
perpendicular to main traffic route.

C. [Finish of Formed Surfaces]{.underline}

1\. Grout-Cleaned Finish: The entire surface of all exposed exterior
concrete shall be given a rubbed grout clean-down finish using a mix of
one part white Portland cement and 1-1/2 parts of fine sand mixed with
sufficient water to form a grout having the consistency of thick paint.
Apply to damp surface and rub down in such a manner as to obtain a
smooth, filled surface uniform in color and free from defects and
blemishes.

2\. Smooth Rubbed Finish: Interior exposed surfaces (where scheduled to
be painted) shall be rubbed with carborundum stones and water to a
smooth, even surface for painting.

## 3.07 [CONCRETE CURING]{.underline}

A. [General]{.underline}: Immediately after placing or finishing, and as
soon as the operation will not mar the finish, concrete surfaces not
covered by forms shall be protected against moisture loss. Curing shall
be accomplished by one of the following methods or a combination
thereof, as approved, and such protection shall be maintained for a
period of at least 7 days. Where formed surfaces are cured in the forms,
the forms shall be kept continually wet. If the forms are removed before
the end of the curing period, curing shall be continued as on unformed
surfaces, using curing materials specified herein. Surfaces shall be
kept free of foot and vehicular traffic during the curing period.

B. [Curing Methods]{.underline}

1\. Polyethylene Coated Burlap Mats: Surfaces shall be covered with the
specified mat lapped 12 inches (304.8 mm). The mat shall be weighted to
prevent displacement. Tears or holes shall be immediately repaired by
patching.

2\. Membrane Forming Curing Compound: This compound shall be applied in
a two coat continuous operation, using not less than the manufacturer\'s
recommended rate of application. If unknown, it shall be applied at 1
gallon (3.79 liters) per 200 square feet (18.58 square meters) for each
coat. Surfaces damaged by construction operations during curing shall be
resprayed at the same rate. Curing compound, if used, shall be
compatible with the floor sealer specified in Section 03012.

3\. Water Curing: Water curing shall be used on surfaces that are to
receive additional concrete or concrete fill, dustproofing and hardening
treatments, stucco, plaster, or painting.

## 3.08 [REMOVAL OF FORMS]{.underline}

The forms for any portion of the structure shall not be removed until
the concrete is strong enough to not be damaged when the forms are
removed.

A. If field operations are not controlled by cylinder tests, the
following periods, exclusive of days when the temperature is below 40°F
(4.4°C), may be used as a guide for removal of forms and supports:

Centering under beams 14 days

Elevated floor slabs 7-14 days\*

Walls 12-24 hours\*

Columns 1-7 days\*

Sides of beams and all other parts 12-24 hours\*

> \*The longer time dictates unless the Sandia Delegated Representative
> approves the lesser time.

B. If field operations are controlled by beam or cylinder tests, forms
may be removed from centering under beams and floor slabs when a 2500
psi (175.77 kgs-sq cm) compressive strength is attained, and it is
approved by the Sandia Delegated Representative.

C. Superimposed loads shall not be placed on or against load carrying
members until a 2500 psi (175.77 kgs-sq cm) compressive strength has
been attained and it is approved by the Sandia Delegated Representative.

## 3.09 [REUSE OF FORMS]{.underline}

Clean and repair surfaces of forms to be reused in work. The shape,
strength, rigidity, water-tightness, and surface smoothness of reused
forms shall be maintained at all times. Any warped or bulged lumber
shall be re-sized before being used. Unsatisfactory forms shall not be
used.

## 3.10 [CONCRETE SURFACE REPAIRS]{.underline}

A. [Patching Defective Areas]{.underline}: Immediately after removing
forms, cut back form ties and remove all fins and loose material.
Honeycombs and voids shall be cut to solid concrete, thoroughly wetted,
and filled with cement mortar composed of one part cement to three parts
sand.

B. [Repair of Formed Surfaces]{.underline}: Remove and replace concrete
having defective surfaces if defects cannot be repaired to satisfaction
of Inspector. Surface defects include color and texture irregularities,
cracks, spalls, air bubbles, honeycomb, rock pockets, fins and other
projections on surface, and stains and other discolorations that cannot
be removed by cleaning. Flush out form tie holes, fill with dry-pack
mortar.

C. [Repair of Slabs-on-Ground]{.underline}: Test surfaces for smoothness
and verify surface plane to tolerances specified for each surface and
finish. Correct low areas during or immediately after completion of
surface finishing operations by cutting out low areas and replacing with
patching compound. Finish repaired areas to blend into adjacent
concrete. Proprietary underlayment compounds may be used when accepted
per 1.04 of this specification. Correct high areas in slabs by grinding
after concrete has cured at least 14 days.

## 3.11 [CONCRETE TRUCK DISCHARGE]{.underline}

A. [Excess Concrete]{.underline}: Excess concrete in mixer trucks that
cannot be immediately used shall be discharged to an area where it will
not create an obstruction or hazard during construction. This concrete
shall be removed from the site in a timely manner to a site approved by
the Sandia Delegated Representative.

B. [Wash Water Discharge]{.underline}: Wash water from mixer trucks
shall be discharged to the ground surface in such a manner and at such a
location that discharge can not escape the construction site or be
washed away to arroyos, storm sewers, or sanitary sewers by
precipitation or other surface flows. Prior to project completion, wash
water residue shall be removed from the site to a location approved by
the Sandia Delegated Representative and the wash water discharge site
shall be cleaned free of debris.

END OF SECTION