Design of Porous Asphalt Mixtures by Using the CAVF Method

To harmonize the conflict between the durability and drainability of porous asphalt mixtures, the coarse aggregate void filling (CAVF) method is introduced to the design of a porous asphalt mixture. Bulk volume relative density is used as a measure to evaluate the compaction effect, and the temperature at which the compacting specimen reaches the maximum bulk volume relative density is selected as the optimum compacting temperature. At this temperature, a porous asphalt mixture specimen is modeled, and its properties, such as water stability, high-temperature stability, permeability, and skid resistance, are tested. Test results show that adopting the temperature at which the compacting specimen reaches the maximum bulk volume relative density as the optimum compacting temperature is reasonable. Moreover, the water stability, high-temperature stability, permeability, and skid resistance of the designed porous asphalt mixture exceed the specification requirements. The designed mixture shows good stability even at a high temperature of 70 ℃. This finding proves that the CAVF method presents advantages when used to design asphalt mixtures with a skeleton interdocking structure.