Atch08ReinforcedConcrete.doc

TDTOE CSS Section 03300

CXTFC CSS Section 03300

DEFENSE THREAT REDUCTION AGENCY

Test Fielding Branch, Construction Engineering Division (CXTFC)

1680 Texas Street, Southeast

Kirtland AFB, NM 87117

SPECIFICATIONS FOR CONSTRUCTION AND SUPPORT SERVICES

SECTION 03300

REINFORCED CONCRETE

28 August 2007 SEQ CHAPTER \h \r 11. GENERAL

1.1

SECTION INCLUDES

1.1.1 Formwork, shoring, bracing, and anchorage.

1.1.2 Concrete reinforcing and accessories.

1.1.3 Cast-in-place concrete.

1.1.4 Control, expansion, and contraction joint devices associated with concrete work.

1.2

SUBMITTALS

1.2.1 Submit shop drawings indicating bar sizes, spacing, locations and quantities of reinforcing steel and wire, bending and cutting schedules, supporting and spacing devices (as required).

1.3

MEASUREMENT AND PAYMENT

1.3.1 Concrete shall be provided as Government furnished material at no cost to the Contractor. The Contractor shall be responsible for transporting all the concrete from the Government operated batch plant located at the intersection of range roads 7 and 13 in the DTRA Admin Park. The Government can batch a maximum of 300 cubic yards in a ten-hour period. If the Contractor wants to place a greater quantity, a written request must be submitted to the COR for coordination and approval three (3) working days before concrete work is to commence.

1.3.2 The cost for all work associated with reinforced, cast-in-place concrete, including forming, reinforcement, transportation and placement is to be included in the Contractor’s price for the concrete.

1.4

REFERENCES

1.4.1 ACI 211.1 ‑ Selecting Proportions for Normal, Heavyweight, and Mass Concrete.

1.4.2 ACI 211.2 ‑ Selecting Proportions for Structural Lightweight Concrete.

1.4.3 ACI 301 ‑ Structural Concrete for Buildings.

1.4.4 ACI 302 ‑ Guide for Concrete Floor and Slab Construction.

1.4.5 ACI 305R ‑ Hot Weather Concreting.

1.4.6 ACI 306R ‑ Cold Weather Concreting.

1.4.7 ACI 308 ‑ Standard Practice for Curing Concrete.

1.4.8 ACI 318 ‑ Building Code Requirements for Reinforced Concrete.

1.4.9 ASTM B221 ‑ Aluminum and Aluminum‑Alloy Extruded Bars, Rods, Wire, Shapes, and Tubes.

1.4.10 ASTM C33 ‑ Concrete Aggregates.

1.4.11 ASTM C94 ‑ Ready‑Mixed Concrete.

1.4.12 ASTM C150 ‑ Portland Cement.

1.4.13 ASTM C260 ‑ Air Entraining Admixtures for Concrete.

1.4.14 ASTM C330 ‑ Light Weight Aggregates For Structural Concrete.

1.4.15 ASTM C494 ‑ Chemical Admixtures for Concrete.

1.4.16 ASTM C618 ‑ Fly Ash and Raw or Calcinated Natural Pozzolan for Use as a Mineral Admixture in Portland Cement Concrete.

1.4.17 ASTM C948 ‑ Test Method for Dry and Wet Bulk Density, Water Absorption and Apparent Porosity of Thin Sections of Glass‑Fiber‑Reinforced Concrete.

1.4.18 ASTM D994 ‑ Preformed Expansion Joint Filler for Concrete (Bituminous Type).

1.4.19 ASTM D1190 ‑ Concrete Joint Sealer, Hot‑Poured Elastic Type.

1.4.20 ASTM D1751 ‑ Preformed Expansion Joint Fillers for Concrete Paving and Structural Construction (Non‑extruding and Resilient Bituminous Types).

1.4.21 ASTM D1752 ‑ Preformed Sponge Rubber and Cork Expansion Joint Fillers for Concrete Paving and Structural Construction.

1.4.22 ACI 304 ‑ Recommended Practice for Measuring, Mixing, Transporting and Placing Concrete.

1.4.23 ASTM C143 Standard Test Method for Slump of Hydraulic Cement Concrete

1.4.24 ASTM C231 Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method

1.4.25 ASTM C31 Standard Practice for Making and Curing Concrete Test Specimens in the Field

1.4.26 ASTM C172 Standard Practice for Sampling Freshly Mixed Concrete

1.4.27 ASTM A615 Standard Specification for Granite Dimension Stone

1.4.28 ASTM A185 Standard Specification for Steel Welded Wire Reinforcement, Plain for Concrete

2. PRODUCTS

2.1

WOOD FORM MATERIALS AND ACCESSORIES

2.1.1 For unexposed concrete, wood shall be “standard” or better grade. Where practical or as noted on the drawings, earth or rock cuts may be used as forms for vertical surfaces when the surface is not exposed and the material is capable of holding as a form.

2.2

REINFORCING AND ACCESSORIES

2.2.1 Reinforcing Steel: Use ASTM A 615, grade 60 deformed bars; ties and stirrups, grade 40 unless specified otherwise in the delivery order.

2.2.2 Welded Steel Wire Fabric: Use ASTM A 185 Plain type in flat sheets.

2.2.3 Chairs, Bolsters, Bar Supports, Spacers: Size and shape for strength and support of reinforcement during concrete placement conditions including load bearing pad on bottom to prevent vapor barrier puncture. Special chairs, bolsters, bar supports, spacers adjacent to weather exposed concrete surfaces to be plastic coated steel type; size and shape as required.

2.3

CONCRETE MATERIALS

2.3.1 Concrete slump shall be determined in accordance with ASTM C 143 at the batch plant and at the site by the CQC Manager. The slump shall be specified in each delivery order. If the slump exceeds the specified amount, the batch shall be rejected. If slump is less than the specified amount, water may be added in accordance with ASTM C 94, to bring the batch into tolerance.

2.3.2 Air content of the concrete shall be determined in accordance with ASTM C 231(type B meter). The total air content of the concrete, as measured at the point of placement shall be within 3 to 6 percent of the concrete volume.

2.3.3 One set of six (6), 6 inch diameter test cylinders shall be cast in accordance with ASTM C 31, at a minimum, for each 100 cubic yards of concrete placed. Test cylinders shall be taken from the discharge of the truck in accordance with ASTM C 172. Truck number, time of placement, air content, unit weight, ambient air temperature, temperature of the concrete, and placement location shall be recorded when cylinders are being cast. Initial curing of cylinders shall be performed on-site in accordance with ASTM C 31. After initial curing and within 24 hours of placement, cylinders shall be transported to the Government testing laboratory located at the DTRA Admin Park.

2.3.4 The Government shall provide final curing of test cylinders and perform compressive strength tests at 7, 14 and 28 days.

2.3.5 Copies of all test records and test results shall be maintained by the CQC Manager and the Government's lab superintendent.

2.4

ADMIXTURES

2.4.1 Admixtures will be utilized in the standard Government concrete mix design.

2.5

CONCRETE MIX

2.5.1 The Government shall provide the mix design.

2.5.2 Aggregate used shall conform to ASTM C 33, Size No. 67 (3/4 inch nominal size) unless specified otherwise in the delivery order.

3. EXECUTION

3.1

EXAMINATION

3.1.1 Verify lines, levels, and centers before proceeding with formwork. Ensure that dimensions agree with the Drawings.

3.1.2 Verify that anchors, reinforcement and other items to be cast into concrete are accurately placed, positioned securely, and will not cause hardship in placing concrete.

3.2

FORMWORK ERECTION

3.2.1 Hand trim sides and bottom of earth forms. Remove loose soil prior to placing concrete.

3.2.2 Erect formwork, shoring and bracing to achieve design requirements.

3.2.3 Provide bracing to ensure stability of formwork. Shore or strengthen formwork subject to overstressing by construction loads.

3.2.4 Arrange and assemble formwork to permit dismantling, stripping and removal of remaining principal shores. Do not damage concrete during stripping.

3.2.5 Align joints and make watertight. Keep form joints to a minimum.

3.2.6 Provide chamfer strips on external corners of beams, joists, columns, and walls.

3.2.7 Apply form release agent prior to placement of reinforcing steel, anchoring devices, and embedded items.

3.2.8 Do not apply form release agent where concrete surfaces receive special finishes or applied coverings, which are effected by agent. Soak inside surfaces of untreated forms with clean water. Keep surfaces coated prior to placement of concrete.

3.2.9 Provide formed openings where required for items to be embedded in or passing through concrete work.

3.2.10 Locate and set in place items, which cast directly into concrete.

3.2.11 Clean formed cavities of debris prior to placing concrete.

3.2.12 Do not remove forms or bracing until concrete has gained sufficient strength to carry its own weight and other imposed loads without excessive deflection or creep.

3.3

REINFORCING PLACEMENT

3.3.1 Place, support and secure reinforcement against displacement. Do not deviate from required position.

3.3.2 Do not displace or damage vapor barrier.

3.3.3 Maintain following minimum (inches) concrete cover around reinforcing:

Concrete cast against and permanently exposed to earth:

Concrete exposed to earth or weather:

#6 through #18 bars

#5 bar, W31 or D31 wire, and smaller

Concrete not exposed to weather or in contact with ground:

Slabs, walls, joists:

#11 bar and smaller

Primary reinforcement, stirrups, ties, spirals 3.0

2.0

1.5

0.75

1.5

3.4

PREPARATION

3.4.1 Prepare previously placed concrete by cleaning with steel brush and applying bonding agent in accordance with manufacturer's instructions.

3.4.2 In locations where new concrete is to be doweled to existing work, drill holes in existing concrete. Install epoxy rebar dowels in accordance with manufacturer's instructions.

3.5

PLACING CONCRETE

3.5.1 Conveying and placing of concrete shall be in accordance with ACI 304, Chapters 5 and 6, and ASTM C94. Conveying and placing equipment shall be of adequate size and capacity to handle the concrete mixes furnished.

3.5.2 Before depositing concrete, all conveying and placing equipment shall be cleaned. Debris, mud, and ice shall be removed from spaces receiving concrete. Compacted soil and surfaces to receive concrete shall be thoroughly saturated before concrete placement, but concrete shall not be placed in standing water.

3.5.3 Concrete shall be deposited at or near its final placement position and shall not be caused to flow so that lateral movement will permit or cause segregation of the concrete components. The stream of concrete shall not be separated by permitting it to fall freely over rods, spacers, reinforcement, or other embedded items. Scattered pieces of coarse aggregate are not objectionable if they can be restored into the mass by vibration. The horizontal flow within the mass from the point of deposition shall be limited to 5 feet. Concrete shall be deposited in layers no deeper than 24 inches.

3.5.4 The CQC Manger shall conduct a pre-placement meeting a minimum of 48 hours prior to commencement of concreting operations.

3.5.5 Ensure that reinforcement, inserts, embedded parts, formed joint fillers, joint devices, and formwork are not disturbed during concrete placement.

3.5.6 Place concrete continuously between predetermined expansion, control, and construction joints.

3.6

CONCRETE FINISHING

3.6.1 Finished surfaces shall be true plane surfaces with a tolerance of ¼ inch in 10 feet unless otherwise shown on the drawings. Surfaces shall be pitched to drain as specified in each delivery order. Surfaces shall be screeded to the required level with a straightedge and finished with a wood float, steel trowel, or broom.

3.6.2 Surfaces designated as having a rough finish and surfaces not designated for finish shall not receive further treatment.

3.7

CURING AND PROTECTION

3.7.1 Immediately after placement, protect concrete from premature drying, excessively hot or cold temperatures, and mechanical injury.

3.7.2 Maintain concrete with minimal moisture loss at relatively constant temperature for period necessary for complete hydration of cement and hardening of concrete.

3.8

DEFECTIVE CONCRETE

3.8.1 Defective concrete is concrete having excessive honeycomb, or embedded debris, or not conforming to required lines, details, dimensions, tolerances or specified requirements.

3.8.2 Do not patch, fill, touch-up, repair, or replace exposed concrete except upon express direction of the Contracting Officer's Representative (COR) for each individual area.

3.8.3 Repair or replace defective concrete as directed by the COR at no cost to the Government.

END OF SECTION

CSS-03330-6

CSS-03300-2

Attachment 8