ITEM 302 – BITUMINOUS TACK COAT

302. 1 Description

This Item shall consist of preparing and treating an existing bituminous or cement concrete surface with bituminous material in accordance with the Plans and Specifications, preparatory to the construction of a bituminous surface course.

302.2 Material Requirements

Bituminous material shall be either Rapid Curing (RC) Cut-back or Emulsified Asphalt, whichever is called for in the Bill of Quantities. It shall conform to the requirements of Item 702, Bituminous Materials. The type and grade shall be specified in the Special Provisions.

302.3 Construction Requirements

302.3.1 Surface Condition

Tack coat shall be applied only to surfaces which are dry or slightly moist. No tack coat shall be applied when the weather is foggy or rainy.

302.3.2 Equipment

Equipment shall conform in all respects to Subsection 301.3.2.

302.3.3 Application of Bituminous Material

Immediately before applying the tack coat, the full width of surface to be treated shall be cleaned of loose and foreign materials by means of a power broom or power blower, supplemented as necessary by hand sweeping. Where required by the Engineer, immediately prior to the application of the tack coat, the surface shall be lightly sprayed with water but not saturated. Bituminous material shall be applied by means of a pressure distributor at the temperature given in Item 702, Bituminous Materials, of the particular material being used. The rate of application of either the Rapid Curing Cut-back or the Emulsified Asphalt shall be within the range of 0.2 to 0.7 liters/m2. The exact application rate for the type of the bituminous material to be ordered by the Engineer shall be based on the condition of the existing bituminous or cement concrete surface.

Care shall be taken that the application of the bituminous material is not in excess of the specified amount; any excess shall be blotted by sand or removed as directed by the Engineer. All areas inaccessible to the distributor shall be treated manually using the device for hand spraying. The surfaces of structures and trees adjacent to the areas being treated shall be protected in such a manner so as to prevent their being spattered or marred.

Traffic shall be kept off the tack coat at all times. The tack coat shall be sprayed only so far in advance on the surface course as will permit it to dry to a “tacky” condition. The Contractor shall maintain the tack coat until the next course has been applied. Any area that has become fouled by traffic or otherwise, shall be cleaned and resprayed at the Contractor’s expense before the next course is applied.

302.4 Method of Measurement

The bituminous tack coat shall be measured by the area covered in square meters (m²).

302.5 Basis of Payment

The accepted quantity, measured as prescribed in Section 302.4, shall be paid for at the contract unit price for Bituminous Tack Coat which price and payment shall be full compensation for furnishing and placing all materials, including all labor, equipment, tools and incidentals necessary to complete this Item.

Payment will be made under:

Pay  Item Number	Description	Unit of Measurement
302 302 (1) 302 (2)	Bituminous Tack Coat RC - Cut-back Asphalt Emulsified Asphalt	Square Meters Square Meters