Mechanical performance and pore characteristics of pervious concrete

Optimal dosages of silica fume (SF) and superplasticizer (SP) for pervious concrete (PC) were determined, and the water-to-binder ratio (W/B) range was 0.22–0.32. Planar pore characteristics were analyzed by the method of image binarisation, d 60 was selected as the core pore size to evaluate pore size distribution characteristics. The influence of W/B, porosity and core pore size on compressive and flexural strength and permeability coefficient of PC was evaluated. The findings indicated that the optimal fluidility ranged from 220 to 280 mm when SF and SP contents were 5 % and 0.5 %. The maximum strength value was achieved when W/B was 0.28. As porosity increased from 12 % to 27 %, the proportion of pores sized 1–5 mm decreased by 11.2 %, while the proportion of pores sized 10–20 mm increased by 18.7 %. As porosity increased from 12 % to 27 %, permeability coefficient increased by 120.41–233.33 %, while compressive strength decreased by 34.09–39.29 %. Furthermore, as core pore size increased from 3.5 to 6.5 mm, the permeability coefficient increased by 75.88–158 %, while the compressive strength decreased by 18.49–24.92 %. A negative linear correlation was observed among porosity, core pore size and compressive strength, whereas quadratic polynomial function relationships were found among porosity, core pore size and permeability coefficient. The PC pavement used in this project demonstrated proper water permeability, high pavement strength, good blockage resistance, and excellent dredging performance. • Optimum ratio of additives was determined to prepare pervious concrete. • Pore size characterization, porosity, mechanical properties of pervious concrete were studied. • Quantitative relationships among strength, permeability coefficient and core pore size were obtained. • Performance of pervious concrete in road applications was evaluated.