Effects of aggregate bulking and film thicknesses on water permeability and strength of pervious concrete

Abstract Pervious concrete is produced by adding less than enough paste to fill the voids in the aggregate to form drainage channels inside the concrete. However, the volume of voids in the aggregate increases after the addition of paste due to aggregate bulking, which has been ignored in previous studies. Moreover, it is still not precisely known how the unfilled voids influence the performance of pervious concrete. In this research, the flowability and adhesion of paste and the bulking of aggregate were investigated and the effects of paste properties, aggregate bulking, water film thickness (WFT) and paste film thickness (PFT) on the permeability and strength of pervious concrete were evaluated. The results revealed that the paste properties, aggregate bulking, WFT and PFT play major roles and thus are the key factors to be considered in the design of pervious concrete. Lastly, a 3-step mix design method for pervious concrete is proposed.