482SLURRY SEAL

482.1DESCRIPTION —This work is construction of a n emulsified asphalt slurry seal course of the type

designated.

482.2MATERIAL—

Provide aggregate with the SRL designation in the Contract Item. Supply the aggregate from an acceptable source for use in wearing courses. The Contractor may supply an aggregate or aggregate blend with an SRL equal to or better than in the Contract Item. Blends are 50% by weight of each aggregate. Mix aggregates by an approved method.

hardness, lower to below 150 ppm (9 grains) by adding water softener.

Provide fine aggregate, asphalt emulsion, water, and, if required, filler conforming to the Representative directed composition by weight percentages that are within the limits of Table A.

TABLE A Composition by Weight Percentages Combined Aggregate Gradations

Percentages by Weight Passing Sieve Type I Type II Type III

3/8-inch 100 100 100 No. 4 100 90 - 100 70 - 90 No. 8 90 - 100 65 - 90 45 - 70 No. 16 65 - 90 45 - 70 28 - 50 No. 30 40 - 60 30 - 50 19 - 34 No. 50 25 - 42 18 - 30 12 - 25 No. 100 15 - 30 10 - 21 7 - 18 No. 200 10 - 20 5 - 15 5 - 15

Asphalt Residue Percent by Weight of Dry Aggregate 10.0 - 16.0 7.5 - 13.5 6.5 - 12.0

from 6 pounds per square yard to 10 pounds per square yard.

wearing surface. Apply dry aggregate at a rate of 10 pounds per square yard to 15 pounds per square yard.

at a rate of 15 pounds per square yard or more.

482.3CONSTRUCTION—

is 50F or lower, or if the pavement temperature is 50F or lower.

capable of accurately proportioning, combining, and mixing the materials into a homogeneous mixture with an asphalt film of sufficient thickness to furnish the desired binding properties. Use an apparatus that contains bins, tanks, and receptacles of sufficient size and volume; proportioning feeders; liquid measuring meters or devices; and a mechanical mixer and distributor for placing the finished mixtures. Materials are to be delivered to the mixer simultaneously and in time -adjusted sequence by integrated, mechanized, and synchronized components.

is required:

• mixing chamber having a stated capacity (not to be exceeded);

• mechanical equipment to regulate mixing time up to, but not exceeding, 4 minutes;

• equipment to pre-wet the aggregate before aggregate contact with asphalt emulsion; and

• a gate for controlling discharge of mixture into the distributor spreader.

assembled with the slurry mixer, and which includes the following:

• a strike-off, lined with flexible material to prevent loss of slurry mixture during spreading;

• a strike-off, with vertical adjustment available for changing grade and cross slope to ensure uniform spreading of mixture; and

• a pressure system and a fog-type spray bar, adequate for placing a complete fog coat of water over pavement surface immediately preceding spreading of mixture, with a maximum 0.05 gallon per square yard application rate of water.

hand equipment, as necessary.

• Seal open joint and cracks with an acceptable crack sealer or emulsion.

• In addition to the surface cleaning specified, also remove heavy paint build -up.

• Cover and satisfactorily protect existing raised pavement markers.

• Replace damaged markers.

temperature of the slurry seal is within the range designated, but not less than 50F or more than 125F.

of fresh slurry, or by lightly wetting the area the spreader box will touch, while the slurry is in a completely uncured, semi-fluid condition.

Do not wet the slurry if it is completely uncured. Pull a burlap bag, or other suitable device, along the joint seam, to cause fresh slurry from the spreader box to distribute itself evenly over the joint. Wet the slurry with the spring bar, if the slurry is completely cured.

to a firm condition that will prevent pick-up of the mixture.

482.4MEASUREMENT AND PAYMENT—Square Yard