SECTION 313—ASPHALT-STABILIZED OPEN-GRADED MATERIAL
313.01 Description
This work shall consist of furnishing and placing a course of asphalt-stabilized open-graded material on a prepared subbase or subgrade in accordance with the required tolerances in these specifications and in conformity with the lines and grades shown on the plans or established by the Engineer.
313.02 Materials
Asphalt-stabilized open-graded material shall conform to Section 211 except as noted herein:
a.Coarse aggregate shall be Grade A crushed stone conforming to Section 203 and shall conform to the soundness requirements of surface course stone.
b.Fine aggregate shall conform to Section 202.
c.Asphalt cement shall be PG 64H-22.
d.Reclaimed asphalt pavement shall not be used as component material.
313.03 Proportioning
Stabilized open-graded material shall be designed to have an in-place coefficient of permeability of at least 1,000 feet per day when tested in accordance with VTM-84. The following design range shall be used for asphalt-stabilized open-graded material: % PassingSieve Min. Max. 1 in 100 100 3/4 in 88 100 1/2 in 70 90 No. 8 0 15 No. 200 0.5 4.5 Asphalt Content 4.3 ± 0.3% 313.03 Hydrated lime shall be used in all mixtures at the rate of at least 0.5 percent by weight of the total dry aggregates. The Contractor may use chemical additives in addition to or in lieu of lime with the Engineer’ s approval. The Engineer’ s approval will be based on previous approvals of chemicals used with the same aggregates in asphalt concrete mixes of other types as detailed in Section 211. The mix temperature shall be between 250 degrees F and 280 degrees F . The Engineer will not require design test data. The Contractor shall perform draindown testing in accordance with VTM-100. Draindown shall not exceed 0.3 percent.
313.04 Acceptance
The Engineer will accept the aggregate coating in asphalt-stabilized open-graded material based upon 100 percent surface coverage of the aggregate as verified by visual inspection.
313.05 Placing limitations
The Contractor shall not place stabilized open-graded material when weather or surface conditions are such that the material cannot be properly handled, finished, or compacted. Asphalt-stabilized open-graded material shall be placed only when the atmospheric temperature is above 40 degrees F and the surface temperature upon which it is to be placed is no less than 35 degrees F . The surface upon which mixtures are to be placed shall be free of standing water. The Engineer will not permit water to be used to cool the asphalt-stabilized open-graded course. The Contractor shall not use vibratory rollers on the asphalt-stabilized open-graded course.
313.06 Procedures
The Contractor shall not place stabilized open-graded material until the Engineer approves the surface upon which it is to be placed. Preparation shall include provision for surface drainage away from the material to prevent contamination from surface water in the event of rainfall. The Contractor shall prevent contamination of the stabilized open-graded material. Material that has been contaminated shall be removed and replaced promptly by the Contractor at no additional expense to the Department. Likely indications of contamination include, but are not limited to, the surface being clogged by dirt or other foreign material or observable material damaged as in the cases of loss of material stability. The finished surface of the stabilized open-graded material shall be uniform and shall not vary at any point more than 0.5 inch above or below the grade shown on the plans or established by the Engineer. The Contractor shall remove and replace stabilized open-graded material with a surface higher than 0.5 inch above the grade shown on the plans or established by the Engineer with material within the proper 313.03
Referenced in this section
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Source: Road and Bridge Specifications, 2020 Edition. Pages 415–416 of 1,065. View official source ↗