SECTION 424 - ASPHALT PLUG JOINTS
424.01 Description
This work shall consist of supplying and installing a blended polymer modified asphaltic binder and aggregate system in layers into a prepared expansion joint block-out on an asphalt concrete overlay on a concrete bridge deck. After installation and curing, the system will provide a flexible waterproof bridge joint which will allow for a joint movement of 1 inch in expansion and 1 inch of compression. The joint shall be placed at a nominal width of 20 inches and a thickness of no less than 2 inches.
424.02 Materials
a.Backer rod shall be expanded closed cell polyethylene foam capable of withstanding the elevated installation temperature (390°F) of the hot binder material and meet the specification requirements of ASTM D 5249.
b.Asphalt binder shall be thermoplastic polymeric-modified asphalt conforming to Table 1 of ASTM D 6297.
c.Aggregate shall be non-polishing of the Basalt, Gabbro or Granite group. All aggregates shall be crushed, double washed, dried and delivered to the job site pre-weighted in weatherproof, labeled bags. The gradation must meet the requirements of joint system manufacturer.
d.Steel backing plate shall conform to the specification requirements of ASTM A36/A 36M, and shall be galvanized in accordance with Section 233. The plate shall have a minimum thickness of 1/4 inch and a minimum width of 8 inches, unless otherwise noted by the joint system manufacturer. 424.02
e.Asphalt plug joint systems shall conform to ASTM D6297 and shall be selected from the Materials Division’ s Approved Products List No. 77
424.03 Procedures
a.General: The Contractor shall submit complete and detailed working drawings of the asphalt plug joint system the Contractor proposes to use for review by the Engineer. The working drawings shall include materials, materials properties, installation procedures, storage, and handling requirements, and materials safety data sheets. The asphalt plug joint shall extend from face-of-curb to face-of-curb. The method for sealing joints in curbs or parapets shall be developed by the Contractor and approved by the Engineer prior to installation. The method for sealing joints in curbs or parapets shall be detailed on the working drawings. Asphalt plug joint systems shall be installed in accordance with the manufacturer’ s instructions. A manufacturer’ s representative shall be present during the entire installation to ensure satisfactory results are obtained. Asphalt plug joint systems shall allow total joint movement of up to 2 inches. The installation shall be centered over the expansion joint gap. The joint shall not be installed when the ambient or substrate temperatures are predicted to be below 40 degrees F at any time during the installation, when precipitation is imminent, or when otherwise prohibited by the manufacturer or the Engineer.
b.Installation: Existing pavement and/or existing joints shall be saw cut to the full depth required for installation of the new plug joint and removed in accordance with the plan details or as directed by the Engineer in order to form the joint block-out. Existing pavement and/or existing joints shall be removed with pneumatic hand tools. Waterproofing membranes, if present, shall also be removed. Small areas of deteriorated concrete in the block-out area shall be repaired with an approved material as directed by the Engineer. The entire joint block-out area shall be cleaned by abrasive blast cleaning and dried using a hot compressed air lance. Backer rods shall be installed in expansion joint openings at a minimum of one (1) inch depth as indicated on the installation details. Backer rod dimensions shall be as required by the manufacturer. Immediately after cleaning and installing backer rod, coat the bottom of the block-out area with a layer of hot binder that has been heated in accordance with the manufacturer’ s instructions. If there is a greater than one hour delay between cleaning and placement of the binder material, the joint shall be re-cleaned using a hot compressed air lance. Steel backing plates shall extend from face of curb to face of curb on the bridge deck portion of the expansion joint. There shall be at least 2 inches between the edge of the backing plate and the wall of the joint block-out. Backing plates shall be steel and dimensions shall be as required by the manufacturer. Locating pins shall only be used when required by the manufacturer of the joint 424.02 system. When required by the manufacturer, locating pins shall be spaced in accordance with the manufacturer’ s instructions. The walls of the joint block-out and the backing plates shall be coated with binder immediately after the steel backing plates are placed, making sure that that the plates are entirely encapsulated by the binder. Aggregate shall be heated in a rotating drum mixer to a temperature between 375 degrees F and the maximum safe binder temperature as specified by the manufacturer. After the aggregate is heated, binder shall be added to the mixer to pre-coat the aggregate. Coated aggregate shall be placed and compacted in the block-out in layers as recommended by the manufacturer. The block-out shall be overfilled with coated aggregate as required to compensate for compaction. Compaction shall begin immediately after placement of the material in the block-out and the joint surface shall be made approximately flush with the existing asphalt surface. The material shall be compacted longitudinally and transversely to the joint using a roller or plate compactor, which delivers a minimum centrifugal force of 3400 pounds. After compaction, lines of 3 inches tape shall be placed one inch beyond the joint width on each side of the joint to insure evenness of appearance. The joint and at least one inch of the road surface shall be top-coated with the hot binder until the surface is smooth and absent of voids. Immediately after top-coating, an anti-skid material shall be spread evenly over the joint to eliminate material tracking. Vehicular traffic must not pass over finished joints until at least two hours after completion of compaction or longer when recommended by the manufacturer. When specified on the plans or directed by the Engineer, an adhesive based joint sealer shall be installed in conjunction with the asphalt plug joint. The details for the installation shall be as shown on the plans. The adhesive based joint sealer shall conform to Section 420. When specified, the adhesive based joint sealer will be measured for separate payment in accordance with Section 420.
424.04 Measurement and Payment
Furnish Asphalt Plug Joint will be measured in cubic feet of material recommended by the joint system manufacturer and approved by the Engineer, and will be paid for at the contract unit price per cubic foot. This price shall include furnishing and delivering the asphalt binder material and aggregate to the project site. Place Asphalt Plug Joint will be measured in linear feet along the centerline of the joint for a nominal width of 20 inches, and will be paid for at the contract unit price per linear foot. This price shall include removing and disposing of existing overlay or pavement material and existing joints and membranes; repairing small areas of concrete deterioration in the block-out area; preparing contact surfaces; placing asphalt binder material and aggregate; furnishing and placing backer rod, anti-skid material, steel backing plates, sealing joints in curbs or parapets; working drawings; and services of the manufacturer’ s representative. 424.04
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Source: Road and Bridge Specifications, 2020 Edition. Pages 629–631 of 1,065. View official source ↗