Specifications.pdf

SECTION 03300A

CONCRETE FOR BUILDING CONSTRUCTION

12/12

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 basic designation only.

ACI INTERNATIONAL (ACI)

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM C 94 1994 Ready-Mixed Concrete

1.2 SUBMITTAL

Government approval of the below mentioned Cementitious Material must take place prior to placement of the concrete. SD-13 Certificates

Cementitious Materials;

Cement, pozzolan, and ground iron blast-furnace slag will be accepted on the basis of manufacturer's certification of compliance, accompanied by mill test reports attesting that the materials meet the requirements of the specification under which it is furnished. No cement, pozzolan, or slag shall be used until notice of acceptance has been given by the Contracting

Officer. Cement, pozzolan, and slag may be subjected to check testing by the Government from samples obtained at the mill, at transfer points, or at the project site.

1.3 GENERAL REQUIREMENTS

1.3.1 Strength Requirements

Structural concrete for all work shall have a 28-day compressive strength of 4000 pounds per square inch.

Concrete slabs on-grade shall have a 28-day flexural strength of 600 pounds per square inch. Concrete made with high-early strength cement shall have a 7-day strength equal to the specified 28-day strength for concrete made with Type I or II portland cement.

1.3.2 Air Entrainment

All concrete shall contain from 4 to 7 percent total air.

1.3.3 Special Properties

Concrete may contain other admixtures, such as water reducers, superplasticizers, or set retarding agents to provide special properties to the concrete, if approved.

1.3.4 Slump

Slump shall be within the following limits:

Structural Element *Slump in inches

Minimum Maximum

Walls, columns and beams 2 4 footings, pavement, and slabs 1 3

PART 2 PRODUCTS

2.1 CONCRETE INGREDIENTS

Concrete shall conform to ASTM C 94; type I & II.

2.2 CURING MATERIALS

Curing materials shall be burlap, impervious sheets, or membrane-forming compounds.

2.3 EMBEDDED ITEMS

Embedded items shall be of the size and type indicated or as needed for the application.

2.4 WATER

Water shall be potable.

2.5 SURFACE COAT FINISH

Drive & Parking Area: Broom Finish

PART 3 EXECUTION

3.1 PREPARATION OF SURFACES

Surfaces to receive concrete shall be clean and free from frost, ice, mud, and water. Conduit and other similar items shall be in place and clean of any deleterious substance. Surfaces shall be moist but without free water when the concrete is placed.

3.2 FORMWORK

Form work shall be mortar-tight, properly aligned, and adequately supported to produce concrete conforming accurately to the indicated shapes, lines, dimensions, and with surfaces free of offsets, waviness, or bulges. Where surfaces are to be exposed or painted, panels shall be of uniform sizes, using smaller panels only where required by openings, joints or for closure. Unless otherwise shown, exposed external corners shall be chamfered, beveled or rounded by moldings placed in the forms. Form surfaces shall be thoroughly cleaned and coated before each use. Forms shall be removed at a time and in a manner that will not injure the concrete.

3.3 COMPACTED FILL MATERIAL

Material shall be approved by COR and obtain a 95% compaction of the maximum dry density.

3.4 DRAINAGE FILL MATERIAL

As specified in the Standard Specifications for Roads and Bridges, South Dakota DOT Sec. 882.2

Table 1, Specified Requirements.

3.5 Not Used.

3.6 Not Used.

Embedded items shall be free from oil, loose scale or rust, and paint.

Embedded items shall be installed at the locations indicated and required

3.7 BATCHING, MIXING AND TRANSPORTING CONCRETE

The work shall conform to ACI 318/318R part Construction

Requirements, except as otherwise specified.

3.8 CONCRETE PLACEMENT

Concrete shall be handled from mixer to forms in a continuous manner until the approved unit of operation is completed. Adequate scaffolding, ramps and walkways shall be provided so that personnel and equipment are not supported by in-place reinforcement. Concrete shall be deposited as close as possible to its final position in the forms. Depositing of the concrete shall be so that all slabs shall be placed in a single layer. Concrete to receive other construction shall be screed to the proper level to avoid excessive shimming or grouting.

3.9 CONSOLIDATION

Vibrators shall not be used to transport concrete within the forms.

Slabs 4 inches and less in thickness shall be consolidated by properly designed vibrating screeds or other approved technique.

3.10 Not Used.

3.11 CONSTRUCTION JOINTS

Expansion and contraction joints shall be made in accordance with the details shown or as otherwise specified.

Construction joints shall be located as indicated or approved. Contraction joints shall be cut at a minimum of 1 inch deep with a jointing tool after the surface has been finished. All joints will be sealed with an approved joint sealant

3.12 FINISHING CONCRETE

3.12.1 Float Finish

Slabs to receive a steel trowel finish. Screeding shall be followed immediately by darbying or bull floating before bleeding water is present, to bring the surface to a true, even plane.

3.12.1.2 Broom Finish.

3.12.1.3 Exposed Aggregate Finish

3.12.1.4 Not Used.

3.13 CURING AND PROTECTION

3.13.1 General

Immediately after placement, concrete shall be protected from premature drying extremes in temperatures, rapid temperature change, mechanical injury and injury from rain and flowing water. Air and forms in contact with concrete shall be maintained at a temperature above

50 degrees F for the first 3 days and at a temperature above

32 degrees F for the remainder of the specified curing period.

3.13.2 Moist Curing

Concrete to be moist-cured shall be maintained continuously wet for the entire curing period. If water or curing materials used stains or discolors concrete surfaces which are to be permanently exposed, the concrete surfaces shall be cleaned. When wooden forms are left in place during curing, they shall be kept wet at all times. If the forms are removed before the end of the curing period, curing shall be carried out as on unformed surfaces, using suitable materials. Horizontal surfaces shall be cured by ponding, by covering with a 2 inch minimum thickness of continuously saturated sand, or by covering with waterproof paper, polyethylene sheet, polyethylene-coated burlap or saturated burlap.

3.13.3 Membrane Curing

Membrane curing shall not be used on surfaces that are to receive any subsequent treatment depending on adhesion or bonding to the concrete.