Attach 1.Spec 4.03 30 04.09R0007.pdf

Solicitation No. FA5270-R-0007

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DIVISION 3 - CONCRETE

SECTION 03 30 04

CONCRETE FOR MINOR CONSTRUCTION

PART 1 - GENERAL

1.1 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only. The most current editions shall be used.

AMERICAN CONCRETE INSTITUTE (ACI):

ACI 301-05 Specifications for Structural Concrete for Buildings

ACI 304R-00 Guide for Measuring, Mixing, Transporting and Placing Concrete

ACI 318-05 Building Code Requirements for Reinforced Concrete

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM):

ASTM C33-07 Concrete Aggregates

ASTM C94-02 Ready-Mixed Concrete

ASTM C143-08 Slump of Portland Cement Concrete

ASTM C171-07 Sheet Materials for Curing Concrete

ASTM C172-07 Sampling Freshly Mixed Concrete

ASTM C260-06 Air-Entraining Admixtures for Concrete

ASTM C494-08 Chemical Admixtures for Concrete

JAPANESE INDUSTRIAL STANDARDS (JIS):

JIS A 1101-75 Method of Test for Slump of Concrete

JIS A 1132-76 Method of Making and Curing Concrete Specimens

JIS G 3112-87 Steel Bars for Concrete Reinforcement

JIS R 5210-92 Portland Cement

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JAPANESE ARCHITECTURAL STANDARD SPECIFICATION (JASS):

JASS Chapter 6 Concrete Construction

1.2 SUBMITTALS

Submit the following in accordance with Section 01 11 00, "General Requirements". See AF Form 66

a. Certificates of Compliance:

1. Cement

2. Aggregates

3. Reinforcement

b. Design Data: The required concrete mix design for precast concrete posts and retaining wall shall be submitted to the Contracting Officer for approval.

c. Certificates: Submit to the Contracting Officer three copies of precast concrete post and retaining wall certificates attesting that the items meet specified requirements, that castings have been properly and thoroughly cured, and that sizes and dimensions conform to those shown on approved drawings.

1.3 DELIVERY

a. Cast-In-Place Concrete: Do not deliver concrete until ready for concrete placement.

b. Precast Concrete Post and Retaining wall: Deliver and handle so as to protect them from warping and similar damage. Store them off the ground and give them proper support until place.

1.4 STORAGE

Store concrete aggregates to prevent contamination or segregation. Store reinforcement of different sizes and shapes in separate piles or racks raised above the ground to avoid excessive rusting. Protect from contaminants such as grease, oil, and dirt. Provide for accurate identification after bundles are broken and tags removed.

PART 2 - PRODUCTS

2.1 CONCRETE:

a. Contractor Mix Design: ACI 301, except as modified herein. Concrete shall have a 28-day compressive strength of 210 kgf/sq. cm. Slump shall be between 2 and 4 inches in accordance with ASTM C143. Provide ASTM C33 aggregate Size No. 57 or 67.

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b. Ready-Mixed Concrete: ASTM C94 or JIS equivalent, except as modified herein. Ready-mixed concrete is defined in this specification as concrete produced regularly by a commercial establishment and delivered to the purchaser in the plastic state.

c. Precast Concrete Post and Retaining wall: The mix-design shall be based on current materials previously evaluated by the concrete producer whose established methods of statistical quality control are in conformance with ACI 318 or JIS equivalent. In the absence of such data, the Contractor shall sample and test the aggregates for the design of concrete. Air entrained concrete may be approved, provided the air entraining agent is added to the mixer to produce 4 percent of air by volume, plus or minus one percent.

2.2 MATERIALS

a. Cement: JIS R 5210. Use one cement manufacturer.

b. Water: Water shall be potable.

c. Aggregates: Obtain aggregates for exposed concrete surfaces from one source. Aggregates shall not contain any substance which may be deleteriously reactive with the alkalies in the cement.

d. Reinforcement: JIS G 3112 Grade 40.

e. Materials for Curing Concrete: Impervious sheeting, ASTM C171; waterproof paper, clear or white polyethylene sheeting, or polyethylene-coated burlap.

f. Admixtures: Admixtures including air entraining, if used, shall have prior approval of the Contracting Officer and shall be from one source. Admixtures, if used, are to be added at the mixer and shall be approved agents conforming to current ASTM C 260 or ASTM C 494.

Admixtures shall be certified by the manufacturer to be free of chlorides.

PART 3 - EXECUTION

3.1 FORMS

JASS, Chapter 6. Set forms true to line adequately supported and grade and make mortar-tight.

The form surfaces shall be smooth and free from irregularities, dents, sags or holes when used for permanently exposed surfacesBefore concrete placement, coat the contact surfaces of forms with a non-staining form coating compound. Prevent concrete damage during form removal. All joints and edges shall be chamfered, unless otherwise indicated.

3.2 PLACING REINFORCEMENT AND MISCELLANEOUS MATERIALS

Provide bars and other reinforcing materials, including wire ties, supports, and other devices necessary to install and secure the reinforcement.

a. Cover and Splicing: ACI 301, unless otherwise indicated.

b. Setting Miscellaneous Material: Place and secure in position before concrete placement.

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3.3 PRECAST CONCRETE POST FABRICATION

The precast items shall be plant fabricated or on-site fabricated and shall be the product of one manufacturer. The Contractor shall be responsible for and governed by all the requirements of these specifications.

3.4 MEASURING, MIXING, TRANSPORTING, AND PLACING CONCRETE :

ACI 304, except as modified herein. ASTM C94; machine mix concrete. Begin mixing within 30 minutes after the cement has been added to the aggregates. Place concrete within 90 minutes of either addition of mixing water to cement and aggregates or addition of cement to aggregates if the air temperature is less than 85 degrees F. Reduce mixing time to 60 minutes if the air temperature is greater than 85 degrees F. Additional water may be added, provided that both the specified maximum slump and water-cement ratio are not exceeded. Do not place concrete when weather conditions prevent proper placement and consolidation; in uncovered areas during periods of precipitation; or in standing water. Prior to placing concrete, remove dirt, construction debris, and water from within the forms. Consolidate concrete greater than 4 inches depth with high frequency, internal, mechanical vibrating equipment supplemented by hand spading and tamping. Consolidate concrete 4 inches or less in depth by tamping, spading, and settling with a heavy leveling straight edge. Concrete temperature from initial mixing through final cure shall not exceed 90 degrees F. Shade the fresh concrete and start curing as soon as the surface of the fresh concrete is sufficiently hard to permit curing without damage.

3.5 SURFACE FINISHES:

Finish of exposed concrete shall be typical with the adjoining concrete surface.

3.6 CURING AND PROTECTION

ACI 301. Protect concrete from injurious action by sun, rain, wind, flowing water, mechanical injury, tire marks, and oil stains. Do not allow concrete to dry out from time of placement until the expiration of the curing period. Forms may be removed 48 hours after concrete placement.

a. Moist Curing: Provide for the removal of water without erosion or damage to the structure.

Provide uniform and continuous application of water throughout the curing period. For temperatures between 40 and 50 degrees F, increase the curing period by 50 percent.

b. Curing Periods: Allow 7 days.

3.7 SAMPLING AND TESTING

a. Sampling: ASTM C172 or JIS A 1132. Collect samples of fresh concrete to perform tests specified.

b. Slump Test: ASTM C143 or JIS A 1101. Take samples during concrete placement.

Perform tests at commencement of concrete placement and for each batch (minimum) or every 10 cubic yards (maximum) of concrete.

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