Recycled Aggregate Concrete: Particle Packing Method (PPM) of Mix Design Approach

Abstract

The reuse of old concrete as a source of aggregate is a reliable alternative to Natural Aggregate (NA) in concrete construction. Because of poor quality of Recycled Aggregate (RA), the performance of Recycled Aggregate Concrete (RAC) is not up to the mark in fresh stage and hardened stage as compared to Natural Aggregate Concrete (NAC). In this work, Recycled Coarse Aggregate (RCA) is replaced 100% to produce RAC. The Particle Packing Method (PPM) is proposed for the mix proportioning of concrete. In PPM, the smaller particles are selected to fill up the voids between large particles and so on. PPM is found out to be cost-effective than IS code method of mix design because of the requirement of lesser quantity of cement. The 7 and 28 days compressive strength of conventional concrete and RAC using PPM design mix are very similar. But, the increment in compressive strength from 28 to 90 days curing is higher for NAC than RAC