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411.03.4 Weather Limitations. The PPEST shall be placed only when the surface is dry and the
surface temperature is at least 50oF and rising.
411.03.5 Time Limitation. The PPEST shall not be placed before June 1 or after September 30.
411.03.6 Tack Coat. An SS-1 or RS-1 asphalt emulsion tack coat shall be applied uniformly over
the surface on which the PPEST is to be placed. The application rate shall be 0.10 ± 0.01 gallons per square yard. The tack coat shall be applied using the proper nozzle settings and the “double coverage” or “triple coverage” techniques outlined in Chapter 5 of the Asphalt Institute publication MS-22 “Construction of Hot Mix Asphalt Pavements.”
411.03.7 Placement. The mix placement temperature shall be as recommended by the supplier
of the modified asphalt binder. Special attention shall be paid to the formation of longitudinal joints. The cold edge shall be as vertical and square as possible. Sloughed or disturbed material at the edge shall be luted back to form a vertical face in alignment with the joint.
411.03.8 Compaction. The compacted thickness of the PPEST shall be 1±1/4 inch. Under no
circumstances shall the minimum thickness be less than ¾ inch. Compaction shall commence immediately after plac ement. All rollers shall weigh at least 10 tons and shall operate in the static mode. Compaction to the specified density shall be attained before the PPEST cools to a temperature 20 oF less than the specified compaction temperature.
411.04 METHOD OF MEASUREMENT. “Paver Placed Elastomeric Surface Treatment” will be
measured by the number of square yards of paver-p laced surface treatment completed in place in accordance with the contract or as directed by the Engineer.
411.05 BASIS OF PAYMENT. The accepted quantities of “Paver Placed Elastomeric Surface
Treatment” will be paid for at the contract unit price per square yard as listed in the Proposal. The price so-stated shall constitute full and complete compensation for all traffic control, including traffic control for adjustment of manholes, gates, catch basins and other such structures; mobile phones; surface preparation; furnishing, transporting, handling, placing and rolling the PPEST material as specified; site clean up; furnishing of all labor, tools, equipment and all incidentals for the satisfactory completion of the work; and all work not specifically identified as separate pay items in the contract provisions. The shim course, including the tack coat applied under the shim course, will be paid for under separate items in the Proposal. Ten percent of the total amount due the contractor will be withheld until at least 60 days after all the contract work specified is completed, the surfaced highways have been opened to traffic and the surface treatment is determined to be performing satisfactorily. 4−49SECTION 412 RUBBERIZED ASPHALT CHIP SEALING
412.01 DESCRIPTION. This specification covers all materi als, equipment, constr uction, application
and post-placement procedures for the rubberized asphalt chip sealing of existing paved surfaces at the locations designated on the plans and as directed by the Engineer. The work shall consist of an application of rubberized asphalt binder followed by an application of pre-coated cover aggregate in accordance with this specification and as directed by the Engineer.
412.02 Materials.
412.02.1 Asphalt Cement. Neat asphalt cement for the rubberized asphalt shall meet all the
requirements of AASHTO MP1a for PG 58-28. The high temperature grade shall not exceed PG 58.
412.02.2 Anti-Stripping Agent. If necessary for water resistance, an anti-stripping agent that is
heat stable and approved by the Engineer shall be added to the neat asphalt cement prior to blending with the granulated rubber. The dosage (up to 1.0% by weight of neat asphalt cement) shall be determined during the course of the surface treatment design.
412.02.3 Granulated Rubber. The granulated rubber shall be vulcanized rubber from the ambient
temperature processing of scrap pneumatic tires. The granulated rubber shall meet the following gradation. No substitutions will be accepted. Sieve % Passing #10 100 #16 90-100 #30 25-75 #80 0-20 The use of rubber of multiple types from multiple sources is acceptable provided that the overall blend of rubber meets the gradation requirements. The length of the individual rubber shall not exceed 1/8". Certification shall be provided by the rubber supplier.
412.02.4 Cover Aggregate. The cover aggregate shall be virgin crushed quarry rock from a
RIDOT approved source. Processed gravel will not be permitted. For the material retained on the #4 sieve, no more than 10% of the particles shall have a flatness or elongation ratio greater than 3:1 (ASTM D4791). The aggregate wear, from resistance to abrasion, shall be a maximum of 30% as determined by the Los Angeles Abrasion test (AASHTO T96). The aggregate shall be pre-heated to a temperature between 280º F and 320º F and be uniformly and completely pre-coated with a PG 64-28 or PG 58-28 prior to application. The asphalt content for the pre-coating shall be determined by laboratory and field testing and be approved by the Engineer. The gradation shall meet the following limits: Sieve Size % Passing 1/2" 100 3/8" 85-100 1/4" 0-25 # 4 0 - 5 # 8 0 - 3 #200 0-2