407.01 407-1 SECTION 407 PRIME COAT , TACK COAT , AND REJUVENATING AGENT DESCRIPTION
407.01 This work consists of preparing and treating an existing surface with asphalt material,
and blotter material if req uired, per these specifications and in conformity with the lines shown on the plans or established. MATERIALS
407.02 Asphalt Material. The type and grade of asphalt material for prime and tack coating
will be specified in the Contract. The asphalt material for all coatings shall meet the applicable requirements of Section 702. The asphalt material for prime and tack coating may be conditionally accepted at the source. The rejuvenating agent shall be accepted before loading into the distributor.
407.03 Blotter Material . Blotter material for prime coating shall consist of aggregate base
course conforming to the requirements specified for base course aggregate on the project. Blotter material for rejuvenating agent shall consist of dry, gritty sand conforming to the fine aggregate gradation of Table 703 -2, or as approved. Blotter material may be accepted in the stockpile at the source or at the roadway before placement. CONSTRUCTION REQUIREMENTS
407.04 Weather Limitations. Prime coat and tack coat shall not be applied under the
following conditions:
1.When the surface is wet.
2.When weather conditions would prevent the proper construction of the prime or tack coat.
407.05 Equipment. The Contractor shall provide equipment for heating and uniformly
applying asphalt material and blotter material. The distributor and equipment shall be capable of uniformly distributing asphalt material at even temperature and uniform pressure on variable widths of surface up to 15 feet at readily determined and controlled rates from 0.05 to 2.0 gallons per square ya rd. The allowable variation from any specified rate shall not exceed plus or minus 0.02 gallon per square yard. Distributor equipment shall include a tachometer, pressure gauges, accurate volume measuring devices or a calibrated tank, and a thermometer for measuring temperatures of tank contents. Distributors shall be equipped with a power unit for the pump and full circulation spray bars adjustable laterally and vertically. The distributor for rejuvenating agent shall also be equipped with the following:
1.Heating facilities with controls to reach a temperature of 130 °F .
2.Circulating system to maintain proper mixture of the rejuvenating agent. 407.06 407-2
407.06 Preparation of Surface. Preparation of the surface to be treated shall include all
work necessary to provide a smooth, dry, uniform surface. The work shall include patching, brooming, shaping to required grade and section, compaction, and removal of unstable corrugated areas. The edges of existing pavements that are to be adjacent to new pavement shall be cleaned to permit the adhesion of asphalt materials.
407.07 Application of Asphalt Material. Asphalt material shall be applied by a pressure
distributor in a uniform and continuous spread. When traffic is maintained, not more than ½ of the width of the section shall be treated in one application, or sufficient width shall be left to adequately handle traffic. Care shall be taken so the applicat ion of asphalt material at the junctions of spreads is not in excess of the specified quantity. Excess asphalt material shall be removed or distributed as directed. Skipped areas or deficiencies shall be corrected. Asphalt material shall not be placed on any surface where traffic will travel on the freshly applied material. The rate of application, temperatures, and areas to be treated shall be approved before application of the coating.
407.08 Application of Blotter Material. If, after the application of the prime coat or
rejuvenating agent the asphalt material fails to penetrate and the roadway must be used by traffic, blotter material shall be spread in the quantity required to absorb excess asphalt material. METHOD OF MEASUREMENT AND BASIS OF PAYMENT
407.09 Asphalt material will be measured and paid for per Section 411.
Blotter material will not be measured and paid for separately but shall be included in the work. Payment for patching will be made at the contract unit price for the various items used for patching. 408.01 408-1 SECTION 408 JOINT AND CRACK SEALANT DESCRIPTION
408.01 This work consists of furnishing and placing an approved hot poured joint and crack
sealant in properly prepared cracks in asphalt pavements. Cracks with a width greater than 1/8 inch and less than 1 inch are to be filled with this material. MATERIALS
408.02 Materials for hot poured joint and crack sealant shall meet the requirements of
subsection 702.04. Using a mixture of different manufacturers’ brands or different types of sealant is prohibited. CONSTRUCTION REQUIREMENTS
408.03 Immediately before applying hot poured joint and crack sealant, the cracks shall be
cleaned of loose and foreign matter to a depth approximately twice the crack width. Cleaning shall be performed using a hot compressed air lance. This lance shall be used to dry and warm the adjacent asphalt immediately before sealing. Direct flame dryers shall not be used. These Cracks shall be filled with hot poured joint and crack sealant flush with the pavement surface. Immediately following the filling of the crack, excess sealant shall be leveled off at the wearing surface by squeegee, a shoe attached to the applicator wand, or other suitable means approved by the Engineer. The squeegeed material shall be centered on the cracks and shall not exceed 3 inches in width or 1/16 inch in depth. The sealant material shall be heated and applied according to the manufacturer’s recommendations. The equipment for heating the material shall be an indirect heating type double boiler using oil or other heat transfer medium and shall be capable of constan t agitation. The heating equipment shall be capable of controlling the sealant material temperature within the manufacturer’s recommended temperature range and shall be equipped with a calibrated thermometer capable of plus or minus 5 °F accuracy from 200 to 600 °F . This thermometer shall be located so the Engineer can safely check the temperature of the sealant material. Overheating of the sealant material will not be permitted. The face of the crack shall be surface dry, and the air and pavement temperatures shall both be at least 40 °F and rising at the time of sealant application. Sealant material picked up or pulled out after being placed shall be replaced at the Contractor’s expense. The Contractor shall have blotter material available on the project in the event it is required to prevent tracking or pulling. If required, blotter material shall be approved by the Engineer and placed at the Contractor’s expense.
Source: Colorado Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 369–370 of 943.