404SEAL COAT

404-1.01 DES CRIPTION. Construct a seal coat on an approved surface, with or without cover

coat material, as specified.

404-2.01 MATERIALS. Use materials that conform to the following, for the type and grade

specified: Asphalt Section 702 Cover Coat Aggregate Subsection 703- 2.05 CONSTRUCTION REQUIREMENTS

404-3.01 WEATHER LIM ITATIONS. Do not apply asphalt material to a wet surface, or when the

surface temperature is below 60 °F, or when weather conditions would prevent the proper penetration and adhesion of the cover aggregate.

404-3.02 EQUIPMENT. Use the following equipment, or its approved equivalent:

404-3.03 PREPARATION OF SURFACE. Clean the roadway surface of all loose material

immediately before applying asphalt.

404-3.04 APPLYING AS PHALT MATERIAL. Apply asphalt material to an approved surface by

means of a pressure distributor in a uniform, continuous spread and within the temperature range specified. Apply asphalt material at the rate specified. If the surface texture is such that as phalt material penetrates the surface, a preliminary application of 0.05 to 0.10 gallon per square yard of surface may be required. Use building paper at the beginning of each spread. Remove and dispose of used building paper. Open the spray bar only when the distributor is moving forward at proper application speed. Correct any skipped areas or deficiencies. Do not exceed maximum application rate at overlaps. Suspend spreading asphalt material early enough in the day to permit the termination of traffic control prior to darkness. Apply asphalt material to only one designated traffic lane at a time. Cover the entire width of the lane in one operation. Spread the asphalt material not more than 6 inches wider than the width covered by the cover coat material. Do not allow asphalt material to chill, set up, or dry. Do not allow the distributor to drip on the surface of the traveled way. 142 ALASKA 2020 404-3.05 APPLICATION OF COVER COAT MATERIAL. Moisten the cover coat material with water the day before the aggregate is to be used. Spread the aggregate at a surface dry or slightly damp condition. Aggregate may be accepted in the stockpile at the source. Gradation will be determined by ATM 304. Immediately following asphalt material application, spread the specified quantity of cover coat material. Do not allow truck or aggregate spreader tires to contact the wet asphalt material. Cover any deficient areas with additional material immediately after the cover coat material is spread. Begin rolling immediately for the full width of the aggregates, and continue until 3 complete coverages are obtained. Complete pneumatic tire rolling the same day the asphalt and cover coat materials are applied. After the application of the cover coat material, lightly broom the surface and maintain for a period of 4 days or as directed. Maintenance of the surface includes the distribution of cover coat material over the surface to absorb any free asphalt material. Do not displace imbedded material. Sweep excess material from the entire surface by means of rotary brooms at the time directed. When applying asphalt material without a cover coat, begin rolling the asphalt material immediately upon application and continue until there is no evidence of kneading action. Make at least one complete roller co verage of the road surface. Do not permit traffic on the seal coat until rolling is completed. Control traffic on seal coats by pilot cars at a speed not to exceed 15 mph for a period of 2 to 24 hours, as directed.

404-4.01 METHOD OF M EASUREMENT. See Sect ion 109. By calculated residual weight for

emulsified asphalt.

404-5.01 BASIS OF PA YMENT. Water for emulsified asphalt is subsidiary.

Payment will be made under: PAY ITEM Item Number Item Description Unit 404.0001.____ Asphalt for Seal Coat, ____ TON 404.0002.____ Seal Coat Aggregate, Type ___, Grading ___ TON 143 ALASKA 2020 SECTION 405 SURFACE TREATMENT

405-1.01 DESCRIPTION . Construct a single or multiple course asphalt surface treatment.

405-2.01 MATERIALS. Use materials that conform to the following:

Asphalt Section 702, for the type and grade specified Surface Treatment Aggregate Subsection 703- 2.05, for the grading specified Blotter Material Suitable clean sand CONSTRUCTION REQUIREMENTS

405-3.01 PRIME COAT. Apply prime coat, when specified, per Section 403, Prime Coat.

Allow a curing period of up to 4 days between the application of the prime coat and the next application of asphalt material, as directed. Maintain the primed surface during the curing period. Repair all holes, ravels and areas deficient in prime with asphalt treated materials, by penetration methods, or other approved procedures.

405-3.02 SURFACE TRE ATMENT. Apply each course (asphalt and surface treatment aggregate

per Section 404, Seal Coat. Allow each course to cure for a period of 4 days before applying additional courses. Surface treatment aggregate may be accepted in stockpile at the source. Gradation will be determined by ATM 304.

405-3.03 OPENING TO TRAFFIC. Keep the highway open to traffic as practicable. As soon as

the final layer is rolled, controlled traffic may be permitted as specified under Subsection 404-3.05.

405-4.01 METHOD OF M EASUREMENT. See Section 109. By calculated residual weight for

emulsified asphalt.

405-5.01 BASIS OF PA YMENT. Water for emulsified asphalt is subsidiary .

Payment will be made under: PAY ITEM Item Number Item Description Unit 405.0001.____ Asphalt for Surface Treatment, ____ TON 405.0002.____ Aggregate for Surface Treatment, Grading ___ TON 405.0003.____ Asphalt for Surface Treatment SY 405.0004.___ _ Aggregate for Surface Treatment, Grading ___ CY