The compactability of an asphalt mixture is related to the heating temperature of the materials, but the heating temperature of reclaimed asphalt pavement (RAP) is limited by the production process of hot-in-plant recycled mixtures. To choose a reasonable heating temperature for RAP according to the compactability, the compaction energy ratio (CER) obtained from the Superpave gyratory compactor compaction curve was developed. The CERs of fourteen kinds of asphalt mixtures made with different RAPs were compared, all of which were different in type, content, and heating temperature. The results indicated that CER is an effective energy index to evaluate the workability of a bituminous mixture, and it considers both the accumulated energy after each gyration and the number of gyrations. It was also found that increasing the heating temperature of the RAP cannot always improve the workability of the recycled mixture, because the higher heating temperature caused more hard-aged bitumen to be blended with soft virgin bitumen during the mixing process. At the same RAP heating temperature, increasing the RAP content made it more difficult to compact the mixture, especially for RAPs with styrene–butadiene–styrene (SBS) modified bitumen, and the recycled mixtures with SBS-modified bitumen were more difficult to compact than those with nonmodified bitumen.

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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.

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