SECTION 482 — SLURRY SEAL
482.1 DESCRIPTION —
This work is construction of a bituminous slurry seal course of the type designated.
482.2 MATERIAL —
(a) Bituminous Material.
Emulsified Asphalt, Class E-8, Section 702
(b) Fine Aggregate.
Having the SRL designation as indicated in the bid proposal and supplied from acceptable sources for use in wearing courses. An aggregate designation or blends, equal to or better than that specified, may be supplied. Blends are 50% by weight and mixed by an approved method.
Section 720.2, and free from harmful soluble salts. If water exceeds 9 grains hardness, lower to below 9 grains by adding water softener.
(e) Composition of Mixture.
Design and test the slurry seal mixture in accordance with ASTM-D3910. Provide fine aggregate, asphalt emulsion, water, and filler, if required, conforming to the composition-by-weight percentages, as directed, but within the limits of Table A. Furnish a mix meeting the requirements of Section 401.2(d)2.
Composition by Weight Percentages
Combined Aggregate Gradations
Percentages by Weight
Percent by Weight
Of Dry Aggregate
1. Type I.
Use to seal cracks, fill voids, and correct surface erosion conditions. Apply at a rate of 6 to 10 pounds of dry aggregate per square yard.
2. Type II.
Used to fill surface voids, correct severe surface erosion conditions, and provide a minimum wearing surface. Apply at a rate of 10 to 15 pounds of dry aggregate per square yard.
3. Type III.
Use to provide a new moderate wearing surface or build up a crown. Apply at a rate of 15 or more pounds or dry aggregate per square yard.
482.3 CONSTRUCTION —
(a) Weather Limitations.
As specified in Section 401.3(a), except do not place mixture when air temperature is 50F or lower, or when temperature of pavement on which it is placed is 50F or lower.
(b) Equipment Requirements.
Produce the mixture in a self-propelled, continuous-flow mixing apparatus 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.
A mixer of the spiraled, multi-blade type, or other acceptable type, with the following 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 prewet the aggregate prior to aggregate contact with asphalt emulsion; and
a gate for controlling discharge of mixture into the distributor spreader.
(d) Spreading Equipment.
A mechanically-operated, squeegee-type distributor is required, one which is integrally 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 assure 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 application rate of 0.05 gallon of water per square yard.
2. Auxiliary Equipment.
Provide hand squeegees, shovels, surface-cleaning machines, and other hand equipment, as necessary.
(e) Conditioning of Existing Surface.
Section 401.3(f), except:
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.
Control the temperature of the components of the completed mixture so application temperature of the slurry seal is within the range designated, but not less than 50F, nor more than 125F.
1. Transverse Joints.
Construct by either overlapping previously cured slurry with 10 to 15 feet 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.
2. Longitudinal Joints.
Construct as follows:
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.
Do not allow traffic on the surface until directed, to allow the slurry seal to completely cure to a firm condition that will prevent pick-up of the mixture.
482.4 MEASUREMENT AND PAYMENT —
Most Current Supplement
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