827.01 Description.
PROCESSED REEF SHELL
827.01 Description.
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.
827.02 Processed 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.
827.03 Processed Shell For Bituminous Bases and Pavements.
Processed shell used in bituminous work shall in addition to the requirements noted in Articles
827.01 and 827.02 require the oversize fraction to be crushed in a mechanical crusher and rescreened.
SECTION 830 CONCRETE CURING MATERIALS
830.01 Burlap Cloth and Waterproof Covering Material.
a.General . 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.
b.Types of Covering Material .
1.Burlap cloth shall conform to the requirements of AASHTO M 182 for Class 4 burlap.
2.White Waterproof Paper shall conform to the requirements of A STM C 171.
3.Polyethylene sheeting (film) shall be white opaque conforming to the requirements of ASTM C 171 modified to omit the elongation requirements when the sh eeting 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.)
4.White Burlap Polyethylene sheet shall conform to the requirements of ASTM C 171.
830.02 Imperviou s 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 applica tion shall be 1 gallon {4 L} to not more than 200 square feet {19 m²}.
830.03 Wetted 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 in ches {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 shal l remain in place until the concrete
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 739–738 of 934.