Whether in the world or in our country due to increased traffic volume and axle loads, the road marks that occur on the roads, that is, grooves, are considered to be the most important deterioration in the superstructure. Therefore, in order to reduce the formation of the wheel mark and increase the life span of the roads, high bitumen-based stone mastic coatings have been developed to provide high grain adhesion and docking.
It is usually preferred over roads where heavy vehicle traffic is intensive.
SMA blends are mixtures with 70-80% coarse aggregate, 20-30-30% fine aggregate and 6-25% high bitumen containing intermittent garding. The coarse grinding of the aggregate frame causes more voids between the aggregate particles.
These cavities are filled with fine aggregate called filler mortar, filler, bitumen or modified bitumen and fibers that prevent bitumen run-off …
Stone Mastic Asphalt was developed in Germany to counter the abrasive properties of spiked snow tires. Following the ban on spiked tires, SMA continued to be used; Because Experiments Asphalt Concrete has been found to perform better than the wear layer. At present SMA coatings are used as wear layer in Germany, Austria, Belgium, USA, Netherlands and other Scandinavian countries. ISFALT has recently used this durable asphalt line in the metrobus line between Cevizlibağ and Avcılar.
The most important feature of SMA is that it has 70-80% coarse aggregate and 7% bitumen ratio. The main features of SMA can be listed as follows.
Resistance to high strength and wheel seal
Better structural internal resistance
Resistance to sliding
Audio absorber feature
Longer service life
Resistance to aging
Various additives are used to prevent the high amount of bitumen used in SMA from flowing over the aggregate and to provide a homogeneous distribution in the material.
(Cellulosic fibers, mineral fibers)