143 ALASKA 2020 SECTION 405
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 144 ALASKA 2020 SECTION 406 RUMBLE STRIPS
406-1.01 DESCRIPTION . Form a series of indentations into the pavement.
406-2.01 MATERIALS. None.
406-2.02 MILLING EQU IPMENT. Use equipment designed to mill rumble strips int o asphalt
pavement capable of providing, in a single pass, smooth (approximately 1/16- inch between peaks and valleys) indentations with crisp clean edges. Equipment will use water with the cutting head, minimize dust creation, and align the indentations with a guidance system that is clearly visible to the operator. CONSTRUCTION REQUIREMENTS
406-3.01 PREPARATION . Inspect roadway to receive rumble strips for acceptable pavement
condition. Repair unacceptable pavement as directed. Stake all locations where milling will start and stop with the specified set back distances and place the edge line. Prepare the roadway for the milling operation by providing a smooth clean surface. Sweep all loose material from the roadway surface in line with the planned rumbl e strips and to each side of the strips for the width of the milling machine plus an additional 12” minimum per side or edge of pavement whichever is smaller, and as directed. Sweep and broom according to Subsection 643-3.04, item. 6.
406-3.02 TOLERANCES FOR RUMBLE STRIPS. Make the edges of the indentation straight,
smooth and free of spalling. Meet the following tolerances:
1.Length and width of indentation: ± 1/2-inch.
2.Depth of indentation: ± 1/16- inch.
3.Spacing between indentations: ± 1/2-inch.
4.Alignment of rumble strip to edge line: ± 1-inch. Rumble strips will be unacceptable if they do not meet the specified tolerances, are not smooth, the edges are not crisp, spalling has occurred, or the pavement surface is damaged from rumble strip installation. Re pair unacceptable rumble strips by grinding out the full width of the strip to a depth of 2- inches, repaving with HMA according to Section 401, and milling new rumble strips. Do not perform repairs in a "patch work" manner. If more than one repair is requi red in a group of rumble strips, repair the entire group. In a continuous run of rumble strips, repair the unacceptable rumble strip and the rumble strips to either side to maintain continuity of the rumble strip run. Repair the unacceptable rumble strips to the satisfaction of the Engineer.
406-3.03 RUMBLE STRI P TEST SECTION. Construct a rumble strip test section, and receive
acceptance prior to production. The equipment, preparation, personnel, and method of operation used for the test section shall be the same as used on the remainder of the work. Install a test section, for each type of rumble strip specified, for a distance of 1/4 mile, or as required by the Engineer. Demonstrate for each type of rumble strip that the equipment and method will pr ovide the desired milled -in rumble strip, including the surface inside each depression, without damaging the surrounding asphalt pavement. If a test section does not meet tolerances, provide new equipment, new method, or make necessary adjustments and ret est. Additional test sections will
Source: Alaska Standard Specifications for Highway Construction, 2020 Edition. Pages 171–171 of 584.