193 407.9 -PROTECTION OF THE PAVEMENT AND TRAFFIC CONTROL : The Contractor shall be responsible for the protection of the surface against damage by their equipment and personnel. Traffic shall not be permitted on any part of the work under construction until the treatment has cured sufficiently to prevent raveling or picking up under traffic. The applicable provisions of 636 shall apply for regulating traffic.
407.10 Quantities of Materials :
The application rates referenced in Table 407.10 shall be used as guide to assure the proper amount of asphalt is distributed over the pavement surface under various pavement conditions. The undiluted application rate refers to the unmodified emulsion tha t meets all standard specifications of the specified grade. When an SS or CSS grade emulsion is diluted with water at the allowable 1:1 ratio, the residual asphalt content is defined as the amount of asphalt remaining on the pavement surface after all wat er has evaporated from the emulsion. Unless otherwise specified on the Plans, the recommended application rates for undiluted and diluted asphalt fog seal shall be as specified in Table 407.10. These rates are provided for guidance and may be adjusted as directed by the Engineer based on field conditions. TABLE 407.10 Surface to be Sealed Application Rate (gal/sy) (Note 1) Undiluted Diluted (1:1) Oxidized HMA 0.06 – 0.08 0.12 – 0.15 Chip Seals See Specification 405 Note 1: Application rates are for slow setting emulsions grades (SS and CSS) that contain approximately 60% asphalt material. Non -Tracking Emulsions may contain different asphalt contents. Refer to manufacturer’s recommendations for application rates.
407.11 Method of Measurement :
No materials shall be removed from the Project for any purpose until the operation has been completed and the quantities of materials incorporated into the operations have been determined, except when authorized by the Engineer. The quantity of “Asphalt Material” for fog seal shall be the number of gallons, prior to dilution, incorporated into the completed work. Any applicable dilution rates, shall be supplied to the Engineer by the Contractor on the material delivery ticket. Dry sand or stone chips used as a blotter course due to excessive use of fog seal shall be considered incidental to the work.
407.12 Basis of Payment :
The quantiti es, determined as provided above, will be paid for at the contract unit prices bid for the items listed below, which prices and payments shall be full compensation for furnishing all the materials and doing all the work prescribed in a workmanlike and acce ptable manner, included all labor, tools, equipment, supplies, and incidentals necessary to complete the work.
407.13 Pay Item :
ITEM DESCRIPTION UNIT 407001 -* Non-Tracking Fog Seal Gallon 407002 -* Fog Seal Gallon *Sequence number 194 SECTION 408 TACK COAT 408.1 -DESCRIPTION : This work shall consist of preparing and treating an existing hot -mix asphalt or concrete surface with asphalt material in accordance with these Specifications and in reasonably close conformity with the lines shown on the Plans or established by the Engineer. 408.2 -MATERIALS : Materials shall conform to the requirements of the following Subs ection of Division 700: MATERIALS SUBSECTION TYPE Asphalt Emulsion 705.4 SS or RS Grades Cationic Emulsified Asphalt 705.11 CSS or CRS Grades Non-Tracking Asphalt Material 705.13 NTSS -1HM or similar* * Refer to MP 401.02.25 for a list of Certified Asphalt Materials. 408.2.1 -Quality Control: Quality control is the responsibility of the Contractor as specified in 106.1. Quality control shall consist of calibrating the distributor to the proper application rate, verifying the volume and temperature measuring devices, and when performed, assuring that the proper dilution rate is maintained. 408.2.1.1 -Acceptance Testing: Approval of asphalt emulsions used for tack coat material will be handled by the Materials Control, Soils a nd Testing (MCS&T) Division. MCS&T maintains a list of all approved asphalt emulsion sources and grades. The local District Materials Section can provide a copy of the latest list. The list is also posted on the MCS&T web page under the heading Approved Source/Product Listing. The use of non-approved material without prior testing by MCS&T may result in nonpayment of the item. CONSTRUCTION METHODS 408.3 -WEATHER RESTRICTION : Tack coat shall be applied only w hen the weather and existing surface are satisfactory to the Engineer and when the temperature of the surface is 40°F or above. When the surface temperature is less than 50°F, care must be exercised to assure that the tack coat “breaks” (Note 1) prior to the application of the hot -mix asphalt. Note 1: Tack coat “break” is the process in which water separates from the asphalt emulsion and the color of the tack coat begins to change from brown to black. The time required for breaking will depend on the type and grade of the emulsion, the application rate, the temperature of the existing pavement surface, and environmental conditions. Tack coat “set” refers to the final stage of the process when water has completely evaporated from the emul sion leaving a thin film of asphalt binder on the pavement. The rate of set depends on the same conditions that control the rate of break of the emulsion.