03310 Structural Concrete Worland Hazmat Building.rtf

STRUCTURAL CONCRETE

WFO Prefabricated Flammable Storage Lockers 03310 -

SECTION 03310

STRUCTURAL CONCRETE

PART 1: GENERAL

1.1 SUMMARY

A. Section Includes: Furnishing and placing 6 – inch (6”) structural concrete, including reinforcing steel, formwork, and gravel subbase.

1.2 SUBMITTALS

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

B. Manufacturer's Literature: Submit for approval five copies of the manufacturer's descriptive data for the admixtures to be used on this project. Include the brand name, description, mix of concrete, (including other admixture), purpose for which used and location in which this concrete shall be placed.

C. Shop Drawings: Submit for approval three copies of shop drawings for the reinforcement to be used on this project. Shop drawings shall show the lengths, bends, and splices.

D. Mix Design: Submit for approval five copies of the design mix and strength test results for each strength, class, and type of concrete to be used on this project using material the Contractor proposes to use on the project. Mix designs and strength test results shall be prepared by a certified testing laboratory.

E. Mill Test Reports: Submit three copies for each shipment of Portland cement and reinforcement to be used on this project.

F. Certificates of Conformance: Submit three copies of the batch certificates for each load of ready‑mix delivered to the jobsite, certifying that the batch conforms to the requirements of this specification.

STRUCTURAL CONCRETE

Worland Hazmat Building 03310 -

1.3 QUALITY ASSURANCE

PART 2: PRODUCTS

2.1 MATERIALS

A. Cement: ASTM C 150, portland cement, Type I. The use of caked or hardened cement will not be permitted.

B. Water: AASHTO T 26. Water shall be clean and free from harmful amounts of acids, alkalis, and organic materials. Potable water is acceptable without testing.

35 to 100 percent shall pass a 3/4-inch sieve;

10 to 30 percent shall pass a 3/8-inch sieve and not over 5 percent shall pass a No. 4 sieve. Percentages are by weight.

2. Fine: ASTM C 33 clean, hard, durable, uncoated sand grains, free from silt, loam and clay and shall meet the following gradation:

95 to 100 percent by weight passing No. 4 sieve;

45 to 70 percent passing No. 16 sieve;

15 to 30 percent passing No. 50 sieve;

3 to 8 percent passing No. 100 sieve.

D. Reinforcing Steel: Shall have a yield point of 40 KSI and shall be ASTM A 615, grade 40.

E. Reinforcement Supports: Shall be of the size and type required.

F. Isolation Joint Material: ASTM D 994. Preformed filler strips shall be the full width and depth of slab or joint. Unless otherwise indicated, the material shall be l/2-inch thick. Joint Sealer: ASTM D 1190.

G. Adhesive for Sealing Joints: Mastic‑type.

H. Membrane Curing Compound: ASTM C 309, Type 1 Class A.

L. Control Joints: Nonstaining wood, plastic, or metal formed to be removed without spalling concrete.

M. Epoxy Bonding Material: ACI 503.1 for hardened concrete or ACI 503.2 for plastic concrete.

2.2 MIXES

2.3 SOURCE QUALITY CONTROL

A. Testing: Contractor shall make arrangements for a certified, independent testing laboratory, according to the requirements of Section 01458 - Testing Laboratory Services, to perform the air content tests, compression tests of 3 cylinders, and slump tests to substantiate mix designs. Record and distribute the results.

PART 3: EXECUTION

3.1 PREPARATION

A. Aggregate Subbase: Shall be placed under the slab prior to erecting formwork, according to Section 02322 ‑ Excavation and Fill for Structures.

B. Form Construction: ACI 347, Chapters 1 through 4. Construct to the exact sizes, shapes, lines, and dimensions shown, and as required to obtain accurate alignment, location, grades, level, and plumb work in finished structures. Provide required detail work, construction aids, and embedded items. Use selected materials to obtain required finishes. Fabricate forms for removal without hammering or prying against concrete surfaces. Provide crush plates or wrecking plates if stripping may damage cast-concrete surfaces. Provide kerfed-wood inserts for forming keyways, reglets, and recesses to prevent swelling and assure ease of removal. Form oil may be applied to facilitate removal of the forms.

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

D. Bonding to Existing Material: Surfaces required to be bonded to the concrete shall be prepared for bonding adhesive according to the manufacturer's instructions.

E. Construction Joints: Shall be made with beveled keyways at locations as approved by the Contracting Officer. Reinforcing steel shall be continuous through joints.

F. Reinforcing Steel: Shall be held securely in position by steel wire or metal chairs during the placement of concrete. Reinforcing steel shall be clean of dirt, grease, and rust prior to placement of concrete.

I. Admixtures that have been approved in writing by the Contracting Officer may be used to aid in setting times when pouring during hot or cold weather conditions.

3.2 CONCRETE PLACEMENT

B. Bonding to Existing Concrete: When a bond is desired between fresh concrete and concrete which has set, the surface of the concrete already in place shall be thoroughly cleaned of loose material, laitance, dirt, and other foreign material, and the old concrete shall be soaked with water. When no bond is desired between the old concrete and the new, the surface of the old concrete that will come in contact with the fresh concrete shall be painted with an asphaltum or other suitable material to prevent bonding.

C. Hot Weather Concreting: ACI 305R.

D. Cold Weather Concreting: ACI 306R. Materials needed 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

B. Form Removal: Formwork not supporting concrete, may be removed after curing at not less than 50 degrees F for 24 hours after placing concrete, and when curing and protection procedures are followed as specified. The concrete shall be sufficiently hard so as not to be damaged by form removal. Formwork and false work supporting live or dead loads of concrete (such as slabs and other structural elements) shall not be removed for a minimum of 14 days, and after the 14 days, not until concrete has attained the design minimum 28-day compressive strength as indicated by test cylinders.

C. Concrete Finish Patching: Immediately after the removal of the forms, remove bulges and projections on exposed concrete by chipping or tooling, and rub or grind the surface. Chip honeycombed or other defective areas to solid concrete; cut edges to right angles with the surface. Brush cavities with a grout of cement and water, and point with a mortar of cement, sand, and water like that used in the concrete. Keep the concrete thoroughly saturated with water during the finishing.

D. Joint Sealing: Use compressed air to blow dirt and dust from joints to be sealed. When joints are dry and dust‑free, apply sealant in the joints according to the manufacturer's instructions. The finished joints shall have no depressions or protrusions and continuous seals shall be formed along the joints.

3.4 CONCRETE CURING

3.5 FIELD QUALITY CONTROL

A. Testing: Testing shall be conducted in the presence of the Contracting Officer who shall be given 48-hours’ notice before tests are to be conducted. The Contractor shall make arrangements for a certified, independent testing laboratory, according to the requirements of Section 01458 - Testing Laboratory Services, to perform the compression and slump testing, recording, and distributing of the results.

B. Air Content Test: ASTM C 231. A minimum of one air content test shall be performed prior to each pour of concrete.

C. Compression Tests: A minimum of one set of test cylinders (each set shall consist of six cylinders) shall be provided each day concrete is placed. An additional set of test cylinders shall be provided on days the pour exceeds 15 cubic yards. The test cylinders shall be made and cured according to ASTM C 31. Twenty‑four hours after taking cylinders, they shall be carefully transported to the testing laboratory for moisture curing. Expense of original sets of tests will be borne by the Contractor. The concrete placement locations represented by the test cylinders shall be noted on record drawings. Test cylinders shall be identified with symbols to indicate the location where the concrete was obtained for the test. Two cylinders are to be tested to failure at 7 days and two at 28 days, according to ASTM C 39. Other cylinders shall be kept for testing in case the 28‑day test falls below required strength.

D. Slump Test: ASTM C 143. A minimum of one slump test shall be performed for each pour of concrete.

3.6 PROTECTION

A. Requirements: Concrete shall be protected from mechanical and chemical damage resulting from construction activities. Floor slabs shall be protected from impact and wheel traffic as well as staining resulting from oils, solvents, chemicals, and paints.

PART 4: MEASUREMENT AND PAYMENT

4.1 METHOD OF MEASUREMENT

A. Units: The work described in this section will be measured and paid for by the cubic yard, based on the dimensions of the structure and the details shown on the drawings. No payment will be made for concrete placed beyond the lines and grades shown. Reinforcing steel will not be paid for separately but is a part of the payment for concrete.

4.2 BASIS OF PAYMENT

A. Payment: Prices and payment will be full compensation for the work described in this section. Payment will be made under:

Pay Item Pay Unit

03310(01) Structural Concrete Cubic Yard

END OF SECTION