Porous asphalt (PA) is a bituminous mixture that is preferred in surface wearing courses because of its comparably better skid resistance and reduced spraying and hydroplaning risk, leading to improved driving quality compared with dense-graded hot mix asphalt mixtures.
Use of recycled materials with satisfactory strength and durability properties as an aggregate in PA mixtures would provide both economic and environmental benefits because natural resources would be preserved, and transportation costs, and consequently CO2 emissions, would be reduced, and the stockpiled recycled material would be employed instead of occupying scarce landscape. However, because of the high air void content and exposure of a larger surface area to atmosphere in PA mixtures, the potential for raveling and rapid aging for any proposed aggregate material needs to be evaluated carefully.