Properties of pervious concrete containing recycled concrete block aggregate and recycled concrete aggregate

The properties of pervious concretes containing two types of recycled aggregates viz., recycled concrete block aggregate (RBA) and recycled concrete aggregate (RCA) were studied. They were incorporated in pervious concretes by replacing natural aggregate at the levels of 0%, 20%, 40%, 60%, 80%, and 100% by weight. Compressive strength, density, total void, water permeability, thermal conductivity and surface abrasion resistance of pervious concrete containing the aggregates were determined. Both RBA and RCA increased the compressive strengths of pervious concretes except at the high replacement level of 100%. The incorporation of RCA at all replacement levels increased the surface abrasion resistance of pervious concrete. For RBA, the improvement in surface abrasion resistance was obtained with only up to 20% replacement level. Although the recycled aggregates were weaker than natural aggregate, the improvements in strength and abrasion resistance were achieved as a result of a better bonding between recycled aggregate and cement paste due to increased surface porosity and roughness of recycled aggregates. The improvements in strength and surface abrasion resistance are important for the utilization of pervious concrete.