What is a Prime coat & What are the applications of Prime coat?

This article is about prime coat material  and the uses of prime coat material also the  function of prime coat materials in Asphaltic roads and highways are highlighted in the article.

Prime coat:

A prime coat is an initial application of low viscosity emulsified or cut back asphalt to an absorbent surface, it is used to prepare an untreated base for an asphalt surfaces. It penetrates into the base and plugs the voids, hardens the top and helps bind it to the over lying asphalt course.

Applications of Prime coat?

  1. Water proofing the surface of the base
  2. Reducing the capillary voids
  3. Coating and bonding loose mineral particles
  4.  Hardening or toughening the surface
  5. Promote adhesion between the base and the overlying asphalt course.


 Range of rate of application of Prime Coat:

 0.65 to 1.75 liters/M².

 In case of the excessive spray what should be done?

 In this case when asphalt is not entirely absorbed by the base within 24 hours the excess should be removed with just enough sand to prevent pick up under traffic.


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