Compressive Strength of Porous Concrete Using Course Aggregate as a Partial Replacement for Fine Aggregate

Abstract

Pervious concrete is a special type of lightweight concrete that is mainly made of cement, coarse aggregates, and water. This study looks at how the strength and porosity of concrete change when fine aggregate is partly replaced by coarse aggregate. Concrete of M15 grade was prepared using different levels of fine aggregate replacement with coarse aggregate. Cube specimens of 150mm x 150mm x 150mm were cast and kept under normal water curing conditions. The study tested porous concrete with 60%, 70%, 80%, and 90% sand replacement and checked the compressive strength at 3,7,14, and 28 days. The compressive strength increased from 10.2 MPa at 60% replacement to a peak of 12.42 MPa at 80%, then dropped to 9.99 MPa at 90%. This shows that 80% sand replacement gives the best performance among all the mixes tested. The results show a clear link between aggregate type and concrete strength. As the replacement level increased, porosity also increased, which affected the strength. Overall, porous concrete shows good potential as a sustainable pavement material, particularly in urban areas where drainage matters. The study concludes that by controlling how much fine aggregate is replaced, a good balance between strength and porosity can be achieved. This makes porous concrete a suitable choice for low load areas such as pedestrian pathways and parking areas.