Hydraulic and strength characteristics of pervious concrete containing a high volume of construction and demolition waste as aggregates

Abstract

Recently, construction and demolition waste generated in Malaysia has dramatically increased. For long-term sustainable development, demolition wastes can be recycled in concrete production. Recycled concrete aggregate (RCA) was successfully used in our previous study as coarse aggregate replacement. This research aims to explore the production of a greener RCA-based pervious concrete by using recycled fine aggregates (RFA). The percentage of waste in the concrete will be 72% by volume of the total concrete mixture constituents. The mixture design is based on a targeted porosity of 15% at the water to cement (w/c) ratios of 0.30, 0.35, and 0.40. Furthermore, the effects of 10% (weight of coarse aggregate) river sand and RFA on the mechanical properties and hydraulic conductivity were compared. The experimental results revealed that 0.35 w/c produced the best mechanical properties. However, the w/c ratio had no effect on the hydraulic properties of the concrete. In addition, incorporating RFA into the concrete improved its mechanical properties, where the compressive and splitting tensile strength of the concrete improved by 7% and 37% respectively. Comparing between RFA and river sand, microscopic analyses showed that the adhered mortar on RFA reduced its crack diversion ability in enhancing the pervious concrete’s strength.