Performance evaluation of alkali activated slag based recycled aggregate pervious concrete

Abstract

The present study attempts, a detailed evaluation of the strength performance of Alkali Activated Slag based Pervious Concrete (AASPC) mixes, containing fly ash and ground granulated blast furnace slag (GGBS) as binders. Fly ash and GGBS, by-product obtained from thermal power plants and steel industries respectively, is incorporated in the AASPC mixes as a full replacement to ordinary Portland cement (OPC). Initially OPC and AASPC mixes are designed to obtain M30 grade. OPC based pervious concrete is considered as control concrete. Pervious concrete is a type of concrete that has a high-water permeability and a higher void content than regular concrete.Experiments investigates the effect of the addition of Recycled Coarse Aggregate (RCA) on the physical and mechanical properties of alkali activated pervious concrete. Certain physical test has been conducted on recycled coarse aggregate to check the quality of aggregates, RCA varying percentage in 0, 25, 50, 75 and 100%, in the mixes. All mixes of alkali activated pervious concrete includes 50% of GGBS and 50% of fly ash from total binder content. Alkali activators used are, sodium hydroxide pellets and sodium silicate liquid. Workability of the alkali activated pervious concrete has a low slump value compare to the control concrete, but the workability of pervious concrete with cement is equal to alkali activated pervious concrete and workability will decreases with increase in RCA percentage because has a high capacity of water absorption. Compressive strength of alkali activated pervious concrete has increased by 23% compared to the OPC based pervious concrete and then there will be a decrease in compressive strength with increase in RCA percentage. The flexural strength and split tensile strength results for both the alkali activated pervious concrete and OPC based concrete shows almost similar values. Permeability and void ratio results shown increase with increase in RCA percentage in AASPC.