Pre-coating of minerals in bituminous compsns - with coal tar pitch in powder form

摘要

Mineral or other solid components of bituminous compsn. are pre-coated with coal tar pitch added in finely granular or dust form during the mixing process, before addn. of the bitumen. Used in bituminous compsns. for building purposes e.g. roads. Adhesion between minerals and binder is improved by first wetting with pitch along. Separate prepn. and transport of bitumen/pitch mixts. and use of molten pitch are avoided. Penetration of water below road surfaces is reduced.