Effect of metakaolin on the properties of pervious concrete

Abstract

Pervious concrete paves way for the reduction of storm water runoff on the urban road surfaces with the aid of its porous nature. The impact of metakaolin as partial replacement for cement in pervious concrete was investigated in this study along with the impact of aggregate sizes. The ratio of aggregate to cementitious material and water to cementitious material were maintained at 3.54 and 0.35, respectively, in all the investigated mixes. Two single sized coarse aggregates with maximum nominal size of 12.5 mm and 20 mm were used. The replacement level of cement in pervious mixes by metakaolin was varied from 0 to 20% at 5% interval. Mechanical properties namely the compressive strength, tensile strength and flexural strength were experimented. The optimum replacement of cement by metakaolin was 15% due to the maximum increase in the mechanical properties. Inclusion of metakaolin at optimum level was found to improve the performance of pervious mixes subjected to static, cyclic and impact loads for both the aggregate sizes.