Evaluating the effect of recycled concrete aggregate and sand in pervious concrete paving blocks

Pervious concrete paving blocks with individual and combined use of recycled concrete aggregate (RCA) and sand were investigated in terms of physical and hydrological properties (density, porosity and infiltration rate), compressive strength and abrasion capacity. First, the natural coarse aggregate was replaced by RCA at the levels of 15%, 30% and 50% by weight. Then, the incorporation of sand at the levels of 5% and 10% by total weight of aggregate was studied in the mixtures that presented the greater performance. As a result, the replacement of natural aggregate by 15% of RCA increased the compressive strength. Also RCA levels until 30% do not compromise the hydraulic and mechanical performance of previous concrete paving blocks. The incorporation of sand decreased the porosity and infiltration capacity of pervious concrete while preventing the mechanical performance to increase due to the lack of homogeneity of the mixture.