A06_-_140L1721Q0025-Section_03306.pdf

MINOR CONCRETE

State Bridge Water System 4/21

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SECTION 03306

PART 1: GENERAL

1.1 SUMMARY

A. Section Includes: Furnishing and placing cast-in-place concrete, including formwork and reinforcement.

1.2 SUBMITTALS

A. General: Submittals shall be according to Section 01009 - General Information and Requirements.

1.3 QUALITY ASSURANCE

A. Causes for Rejection: Concrete may be rejected for, but not limited to, the following reasons:

1. Freezing within the first 3 days of placement

2. Excessive or inadequate slump

3. Segregation of aggregate or over-vibration resulting in excessive water in the surface of the concrete

4. Honeycomb over 25% of the surface

5. Voids larger than 2 inches

6. Failure to cover or seal concrete during initial 7-day curing period.

PART 2: PRODUCTS

2.1 MATERIALS

A. Water: Potable water shall be used for mixing concrete.

B. Sack Concrete Mix: Shall be designed for a 28-day compressive strength of 4000 psi, and a slump of 4 inches as determined by ASTM C 143.

C. Ready Mix Concrete: Ready-mixed concrete shall be according to ASTM C 94 and be designed for a 28-day compressive strength of 4000 psi, and a slump of 4 inches as determined by ASTM C 143.

D. Mixing Materials: Concrete shall be machine mixed. Mixers shall be batched according to their capacity and not overloaded. Mixing of ingredients shall continue for at least 3 minutes and until a uniform color is obtained. The concrete shall be placed as soon as possible after mixing to prevent cold joints.

PART 3: EXECUTION

3.1 PREPARATION

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A. Subbase Preparation: Subbase and earth walls to be in contact with concrete shall be undisturbed or compacted according to Section 02322 - Excavation and Fill for Structures.

B. Form Construction: ACI 347R. Construct forms to the sizes, shapes, lines, and dimensions shown on the drawings, to obtain accurate alignment, location, grades, and level and plumb surfaces in finished structures.

Forms and subbase shall be wet before placement of concrete.

C. Form Inspection: Notify the Contracting Officer 24 hr in advance of concrete placement to allow for inspection of forming and placement of items to be imbedded in the concrete. Excess water shall be removed from the forms before concrete placement.

3.2 CONCRETE PLACEMENT

A. Placement and Consolidation: Each lift shall be adequately vibrated, rodded, or spaded into place to fill voids. Vibrators shall not be used next to the form or to move concrete. Concrete shall be deposited as nearly as practical to its final position to avoid flow causing segregation of the aggregate.

B. Concrete Placement Under Adverse Conditions: During hot weather, refer to ACI 305R. During cold weather, refer to ACI 306R. Materials required for protection shall be on the jobsite before concrete work is started.

Do not place concrete on a frozen subgrade or against surfaces having deposits of frost, snow, or ice.

3.3 CONCRETE FINISHING

A. Concrete Surface Finishes: The top surface of the slab shall be given a broom-finished with horsehair or straw brooms. Brooms shall have a minimum width of 18 inches. Edges shall be edged with a metal tool to leave a smooth border on the concrete.

B. Form Removal: Formwork not supporting concrete may be removed after curing at not less than 50 degrees F for 24 hours after placing the concrete, and when curing and protection procedures are followed as specified. The concrete should be sufficiently hard so as not to be damaged by form removal.

C. Concrete Curing Compound: Clear all resin, dissipating water based curing compound, meeting ASTM C-309 requirements. Dayton Superior J11W or approved equal.

PART 4: MEASUREMENT AND PAYMENT

4.1 METHOD OF MEASUREMENT

A. Units: The work described in this section will not be measured for payment.

4.2 BASIS OF PAYMENT

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A. Payment: No direct payment for the work described under this section will be made. Consideration for this item shall be included in the bid price for other items of the Contract.

END OF SECTION