EVALUATION OF STRENGTH AND INFILTRATION CHARACTERISTICS OF POROUS CONCRETE MADE USING RECYCLED CONCRETE AGGREGATE

Abstract: Porous concrete for low-impact development has long been studied for the improvement of urban stormwater management. However, the porous concrete made using Recycled Concrete Aggregate (RCA) is still lacking, particularly concerning its strength and infiltration rates. Therefore, this paper aimed to design porous concrete using RCA with optimum infiltration rate without compromising the strength. To fulfill this aim, a laboratory study evaluating the strength and infiltration characteristics of a porous concrete mix is presented. From the mixed design 1: 0.4: 3.6 (Portland Pozzolana Cement (PPC): natural sand: natural coarse aggregate), Natural Coarse Aggregate (NCA) is partially replaced by RCA in the interval of 0%, 15%, 30%, and 45% to find the optimum infiltration without compromising the strength. The 10 mm aggregate is used as it was recorded for the highest compressive strength after curing for 28 days. With the increase in the addition of RCA, the compressive strength decreases whereas the infiltration rate increases. From the comparative study of infiltration rate and compressive strength, 30% replacement of NCA with RCA in the ratio of 1:0.4:1.08:2.52 (cement: fine aggregate: RCA: NCA) is found to give the most satisfactory result with infiltration rate and compressive strength of 9737 mm/hr and 8.67 MPa respectively. The water quality test is conducted to evaluate whether the porous concrete detention system can reduce the pollutants from the surface run-off. The pH and acidity parameters are considered to check the quality of stormwater. Stormwater after infiltrating through the prototype becomes basic in nature.