ITEM 408  PRIME COAT

408.01  Description

408.02  Asphalt Material

408.03  Cover Aggregate

408.04  Weather Limitations

408.05  Equipment

408.06  Preparation of Surface

408.07  Application of Asphalt Material

408.08  Application of Cover Aggregate

408.09  Method of Measurement

408.10  Basis of Payment

 

408.01  Description.  This work consists of preparing and treating an existing surface with asphalt material, and cover aggregate if required.

408.02  Asphalt Material.  Conform to the applicable requirements of 702 for asphalt material and use one of the following types:  702.02 RC-70, RC-250, MC-30, MC-70, or MC-250; or 702.03 Primer 20.

408.03  Cover Aggregate.  Use cover aggregate conforming to No. 9 size or gradation requirements of 703.05 or 703.06.

408.04  Weather Limitations.  Do not apply asphalt material on a wet surface.  Do not apply prime coats for asphalt concrete or surface treatment work when the atmospheric temperature is below 50 °F (10 °C) or when the air temperature within the preceding 24 hours has been 40 °F (5 °C) or lower.  The Contractor may apply prime coats on stabilized and granular base courses, when the atmospheric temperature is 40 °F (5 °C) or higher.

408.05  Equipment.  Use equipment conforming to 407.03.

408.06  Preparation of Surface.  Shape the surface to be primed to the required grade and section.  Ensure the surface is free from all ruts, corrugations, segregated material or other irregularities and is smooth and uniformly compacted at the time of application of the asphalt material.  Clean the surface in a manner that will thoroughly remove all mud, earth, and other foreign material.  Take care to clean the edges of road to be primed to ensure uniform application of the asphalt material directly onto the existing base or pavement surface.  Remove material cleaned from the surface and dispose of it as the Engineer directs.

408.07  Application of Asphalt Material.  Apply asphalt material in a uniform continuous spread to the width of the section to be primed by means of a distributor conforming to 407.03.  When traffic is maintained, do not treat more than one-half of the width of the section in one application.  Take care that the application of asphalt material at the junction of spreads is not in excess of the specified amount.  Squeegee excess asphalt material from the surface.  Correct skipped areas or deficiencies.

When traffic is maintained, allow one-way traffic on the untreated portion of the road bed.  As soon as the asphalt material has been absorbed by the surface and will not be picked up, transfer traffic to the treated portion and prime the remaining width of the section.  The Engineer will approve the quantity, rate of application, temperatures and areas to be treated before application of the prime coat.

408.08  Application of Cover Aggregate.  If, after applying the prime coat, the asphalt material fails to penetrate and traffic must use the roadway, spread cover aggregate in the amount required to absorb any excess asphalt material.

408.09  Method of Measurement.  The Department will measure Prime Coat by the number of gallons (liters) according to 109.

408.10  Basis of Payment.  The cost of cover aggregate is included under Prime Coat.

The Department will pay for accepted quantities, complete in place, at the contract price as follows:

Item           unit                                Description

408          Gallon (Liter)         Prime Coat