6-2 to cover areas inaccessible to the spray bars. Equip the distributor with a positive shut -off
control for the spray bar and hand hose.
600-6 Application Rates and Temperatures
Apply the prime coat at a rate from 0.20 to 0.50 gal/sy . The exact rate for each application will be established by the Engineer before application. The required rate of application of asphalt materials will be based on the volume of material measured at the application temperature. Apply the prime coat material at a temperature that is in accordance with the manufacturer's recommendations or as approved by the Engineer .
600-7 Application of Prime Coat
Apply the prime coat only when the base to be treated has been approved by the Engineer . Cover bridge floors, curbs and handrails of structures and all other appurtenances to protect them from t racking or splattering of prime coat. After the prime coat has penetrated sufficiently and when directed by the Engineer , roll the primed surface until all loose base material is thoroughly bonded.
600-8 Maintenance and Protection
When directed by the Engineer , apply blotting sand in accordance with Section 818. Maintain the prime coat in an acceptable condition until such time as the pavement is placed. Replace any damaged prime coat.
600-9 Measurement and Payment
Ensure the volume of the distributor tank is calibrated by a commercial laboratory or the manufacturer before use. Provide a calibration chart with an accurately calibrated measuring stick graduated in increments of not more than 25 gal on the distributor at all times for use by the Engineer. Prime Coat will be paid at the contract unit price per gallon of prime coat material satisfactorily placed on the roadway. Each distributor load of prime coat material delivered and used on the project will be measured. Repair damaged prime coat at no cost to the Department. Blotting Sand will be paid in accordance with Article 818 -4. Payment will be made under: Pay Item Pay Unit Prime Coat Gallon
605-1 Description
Apply tack coat material to existing asphalt or concrete surfaces in accordance with these specifications . Apply tack coat beneath each layer of asphalt plant mix to be placed. Where a prime coat or a newly placed asphalt surface treatment mat coat has been applied, apply tack coat as directed by the Engineer .
605-2 Materials
Refer to Division 10.
6-3 Item Section
Asphalt Binder, Grade PG 58 -28 1020 -2 Asphalt Binder, Grade PG 64-22 1020 -2 Emulsified Asphalt, Grade CRS -1 1020 -3 Emulsified Asphalt, Grade CRS -1H 1020 -3 Emulsified Asphalt, Grade CRS -2 1020 -3 Emulsified Asphalt, Grade HFMS -1 1020 -3 Emulsified Asphalt, Grade RS -1H 1020 -3 Do not dilute or mix the tack coat material with water, solvents or other materials before application. Unless otherwise specified in the contract, use any of the grades of tack coat material specified in this article. For tack coat beneath an open- graded asphalt friction course, the asphalt grade and rate of application to be used on the project will be specified in accordance with Section 650 -5.
605-3 Weather Limitations
Apply tack coat only when the surface to be treated is dry and when the atmospheric temperature measured at the location of the paving operation away from artificial heat is 35°F or above. Do not apply tack coat when the weather is foggy or rai ny.
605-4 Surface Preparation
Ensure that the existing asphalt or concrete surface is free of all dust and foreign material before applying the tack coat. Remove grass, dirt and other materials from the edge of the existing pavement before the placement of tack coat. Properly dispose of these materials as directed by the Engineer.
605-5 Acceptance of Asphalt Materials
The acceptance of asphalt materials will be in accordance with Article 1020 -1.
605-6 Application Equipment
Provide equipment for heating and uniformly applying the asphalt material in accordance with
Article 600 — 5.
605-7 Application Rates and Temperatures
Apply tack coat uniformly across the existing surface at target application rates shown in Table 605 -1. TABLE 605-1 APPLICATION RATES FOR TACK COAT Existing Surface Target Rate (gal/sy) Emulsified Asphalt New Asphalt 0.04 ± 0.01 Oxidized or Milled Asphalt 0.06 ± 0.01 Concrete 0.08 ± 0.01 Apply tack coat at a temperature within the ranges shown in Table 605- 2. Tack coat shall not be overheated during storage, transport or at application.