Crushed stone mastic asphalt concrete

The edge of a freshly laid layer of gravel and mastic asphalt in Moscow , 2017

Crushed stone mastic asphalt concrete (SCMA) or crushed stone mastic asphalt is a type of pavement developed in the 1960s in Germany . Differs in high durability, is suitable for heavily loaded highways .

ASM is characterized by a high content of crushed stone of dense rocks , which forms a stone skeleton that successfully resists deformations. Another feature of ASA is the presence of stabilizing fiber additives, usually cellulose fibers , which are designed to keep the binder ( bitumen ) from draining. A typical composition of alkali alkali metal grades includes 70–80% of gravel, 8–12% of filler , 6–7% of binder, and 0.3–0.5% of fiber.

In some countries, in particular Great Britain and Australia, fears are expressed that under certain conditions, a sufficient level of adhesion to ASHM can be achieved after several months of operation of the road.