A synthetic asphalt being a composition of either bitumen sand and limestone dust orbitumen and limestone dust

摘要

A paving and roof composition is made from bitumen, sand, and limestone dust or from bitumen and limestone dust, by heating the bitumen to melting and adding the filling material when in a heated condition. The bitumen may be pure mineral bitumen or petroleum bitumen. No proportions given. Reference has been directed by the Comptroller to Specification 13662/85, [Class 22, Cements &c.].