Analysis of Increase Reason on AC-13 Asphalt Mixtures Voids

We make specimens with different gradation types ,different fine aggregates , different molding methods, we calculate their air voids , we analyze the cause of increased porosity of mixture from different aspects. The results show that when we use the same aggregate and the same gradation, the air voids show small difference from the designing method of Gyratory Compactor and Marshall ; when we use the same molding methods and and gradations and different fine aggregates to form specimens, the void ratio of basalt fine material is larger,the the void ratio of limestone fine material is smaller; The main reason is the bulk density of basalt fine aggregate is larger,and it is not easy to compaction.