What is Stone Mastic Asphalt?
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What is Stone Mastic Asphalt?
Release Time:2023-10-30
It is a type of asphalt resistant to deformation, suitable for roads with heavy traffic. It has been used in airport projects in recent years. Stone Mastic Asphalt (SMA) is a hot asphalt mixture containing 70-80% coarse aggregate, 20-30% fine aggregate and 6-7% high bitumen. It was developed in Germany in the 1960s and was first applied in Kiel, Germany.

Due to the coarse aggregate being dense in the mixture, gaps occur between the aggregates. These gaps are filled with mastic mortar (fine aggregate, filler, polymer modified bitumen, cellulosic fiber).
Stone Mastic Asphalt_1Stone Mastic Asphalt_2
Bitumen and mineral aggregate should be heated at a minimum temperature of 175 °C (degrees) and a maximum of 190 °C (degrees).
Plant: It should have the equipment to automatically feed the fiber additive and filler material at the intended weight.
The prepared hot mixture should be stored in a hot asphalt bunker with heating and insulation.
Holding of the mixture in the hot asphalt bunker should be within a certain time.
When the hot mixture is delivered to the paver, the air temperature should be minimum 10 °C and the mixture temperature should be minimum 170°C.
Due to the greater amount of coarse aggregate (remaining on the No.4 screen) in the mix design, the load carrying capacity is higher than dense graded bituminous asphalt as the contact of the stone with the stone is increased.
Generally, basalt or similar aggregates with high silica content are used, so abrasion resistance is high.
Studies show that SMA is more successful than bituminous asphalt in terms of surface texture and slip resistance.
Since it contains more modified bitumen than bituminous asphalt, it is more resistant to thermal cracks.
Likewise, it has higher resistance against fatigue cracks.
It provides quieter and more comfortable driving due to its mastic structure.

Fiber additive unit applicable for the production of stone mastic asphalt
Power asphalt plants are designed for stone mastic asphalt production and we have a module in our software system.Also we produce cellulose dosing unit.With our experienced staff, we provide not only plant sales, but also after-sales operation support and personnel training.