Porous Asphalt reduces both noise and splashing on asphalt roads and therefore makes driving on such roads safer.
It is recommended on ring roads around cities where it can reduce noise levels for the people living close to those roads. A further use of porous asphalt is on motorways, where the water drainage capacity increases the visibility under rainy conditions and thus traffic safety.
The noise reduction and reduced splashing of porous asphalt are due to its very open structure (pore volume 21%). This large pore volume in this asphalt is achieved by the gradation of the mixture. Porous asphalt is an example of a so-called “gap graded” asphalt where a certain fraction (mid-fraction) of the stones is eliminated from the gradation, which leaves large pores in the structure.
The open structure of porous asphalt is of course quite sensitive to forces exerted on it by the tires of a vehicle. The best way to avoid as much as possible the raveling and stone-loss is to use Atlantipol Porous, a special polymer modified bitumen, in the production of the porous asphalt which provides a better adhesion between stones and bitumen.