827PROCESSED REEF SHELL

695

LOCAL SAND AND SAND-GRAVEL FOR MISCELLANEOUS CONSTRUCTION USE

826.01Description

Local materials, for the purpose of these Specifications, shall be of the kind and character of local sand and local sand-gravel or blends thereof.

826.02General Requirements

The kind of material shall meet the general requirements for the respective classification of material as noted in this Article. Blends shall consist of any combinations of local sand or sands, or local sand-gravel, or sand-gravels. All blends shall be of the material proportions or ratio provided by the plans and/or proposal. When used in bituminous pavements, local source material shall be non-plastic.

Local sand shall be pit-run sand suitable for the purpose intended. In general, all local sand shall consist of grains of hard, sound material, predominantly quartz or other hard, durable rock, including friable, loosely bound deposits of sandstone conglomerate. The sand shall be free from a coating of injurious material, lumps of clay, loam, organic matter, or other foreign material. If necessary, gradation and/or other requirements will be provided in the plans and/or proposal form.

Local sand-gravel shall be pit-run sand-gravel, suitable for the purpose intended. In general, the sand-gravel shall be hard, sound durable rock, including friable, loosely bound sandstone conglomerate, with varying amounts of coarse aggregate and sand. The coarse aggregate and the sand shall be free from a coating of injurious material, lumps of clay, loam, organic matter, or other foreign material. If necessary, gradation and/or other requirements will be provided in the plans and/or proposal form. PROCESSED REEF SHELL

827.01Description

Processed Reef Shell shall consist of dead reef shells (oyster, clam, or other dead shell as encountered in the reef) but not cannery or live shell. Processing shall consist of washing the shell by the use of a screen washer, the mesh of which shall not be smaller than 1/4 of an inch {7 mm}. The processed shell shall be classified as a commercial aggregate.

827.02Processed Shell For Soil Or Aggregate Base Courses

Processed shell used in base courses shall, after processing, not contain foreign matter in excess of three percent when washed over a No. 200 {75 µm} sieve of the dry weight {mass} of the shell.

827.03Processed Shell For Bituminous Bases and Pavements

Processed shell used in bituminous work shall in addition to the requirements noted in Articles

and 827.02 require the oversize fraction to be crushed in a mechanical crusher and rescreened

CONCRETE CURING MATERIALS 696

CONCRETE CURING MATERIALS

830.01Burlap Cloth and Waterproof Covering Material

Burlap cloth and waterproof covering material shall be of sufficient length and width to extend beyond the edge of the concrete a distance of at least twice the thickness of the slab. Sections of covering material shall be lapped at least 18 inches {450 mm}. The surface and both sides of a concrete slab shall be completely covered. The covering shall be so placed and secured as to cause it to remain in total contact with the exposed surface. Burlap cloth shall be saturated with water before being placed and shall be kept wet while in position. The covering shall remain in position for six days after the concrete has been placed unless otherwise specified or directed.

171 modified to omit the elongation requirements when the sheeting is internally reinforced with a cord net having a cord spacing of 1/4 to 1/2 of an inch {6 to 13 mm}. (Net may be nylon or other approved material.)

830.02Impervious Membrane

Impervious membrane compounds shall meet the requirements of ASTM C 309, Class A. Type 2 white pigmented shall be used on concrete pavement. Other types may be used on other concrete. Membrane liquid shall be applied under pressure with spray nozzles in such a manner as to cover the area being treated with a uniform film. For concrete pavement the rate of application shall be 1 gallon {4 L} to not more than 135 square feet {13 m²}, applied in two applications. For sidewalks the rate of application shall be 1 gallon {4 L} to not more than 200 square feet {19 m²}.

830.03Wetted Earth Or Sand

When this type of curing is used, the pavement shall be cured initially with burlap cloth, polyethylene sheets, or waterproof paper, as specified in Article 830.01, until after final set of the concrete or, in any case, for 12 hours after placing the concrete. As soon as the covering material is removed, the surfaces and sides of the pavement shall be covered with a blanket of earth or sand not less than 2 inches {50 mm} thick. If the earth or sand covering becomes displaced during the curing period, it shall be replaced to the original depth and saturated with water for three days and thoroughly wetted down during the morning of the fourth day; the cover shall remain in place until the concrete has attained the required strength. When permission is given to open the pavement to traffic, the covering material shall be removed and the pavement cleaned and swept. Earth or sand used in this method of curing shall be free of sticks, stones, or other matter which might injure the surface of the concrete. The material shall contain no ingredients which would be detrimental to the concrete or discolor the surface finish.

830.04Straw

Straw used as a supplement to the curing materials noted in Article 830.01 and 830.02 for cold weather protection shall be suitable for the purpose intended and approved each time it is used. PRECAST CONCRETE PRODUCTS

831.01Description

All precast concrete products, except precast non-prestressed concrete bridge members, shall be furnished from an approved producer that is participating in, and meeting the requirements given in ALDOT-364. ALDOT 364 is the "Procedure for Inspection of Concrete Pipe, Precast Manholes, Precast Box Culverts, and Miscellaneous Precast Concrete Products".