Novel gradation design of porous asphalt concrete with balanced functional and structural performances

Abstract

To improve the permeability of porous asphalt concrete (PAC) with a small nominal maximum aggregate size (NMAS) of 10 mm (PAC10), a novel gradation design by excluding the 0.075–3 mm aggregate was developed. This study aims to evaluate the functional and structural performances of the novel PAC10 with various mineral filler contents, using the conventional PAC10 and 13 mm NMAS PAC (PAC13) as reference, and develop the optimum gradation of the novel PAC10. The performance properties evaluated include moisture susceptibility, durability, high-temperature stability, low-temperature cracking resistance and permeability. The results indicated that for the two conventional PACs with the same fine aggregate and mineral filler content, PAC10 had worse permeability and rutting resistance, similar moisture susceptibility and durability, and better low-temperature cracking resistance, compared with the PAC13. The novel PAC10 showed better permeability than the conventional PAC10. With the increase of the mineral filler content, the structural performance of the novel PAC10 is improved, but its permeability is decreased. With a mineral filler content of 6%, the novel PAC10 can have balanced functional and structural performances, which are equivalent to those of the conventional PAC13.