Effect of Casting Technique on the Compressive Behaviour of Fully Recycled Aggregate Concrete

Abstract

The research work presented in this contribution investigated the impact of Compression Casting Technique (CCT) on the compressive behavior of fully Recycled Aggregates Concrete (RAC). RAC mix containing 30% fine aggregates, 70% coarse aggregates and 15% cement by weight of total aggregates was prepared under two different casting pressures (i.e., 25 & 35 MPa). For the purpose of comparison, Natural Aggregate Concrete (NAC) mix was also prepared under same casting pressures. Samples of RAC mix were also made by compaction through vibration. Recycled concrete aggregates required for this study were prepared by crushing of damaged concrete samples having compressive strength in the range of 21 to 28 MPa. Compressive response was evaluated in terms of compressive strength and modulus of elasticity (MOE). Ultrasonic pulse velocity test was employed to check the quality of internal matrix of concrete samples prepared by CCT and vibration. The results demonstrated positive effect of CCT on the properties of concrete resulting in higher compressive strength and MOE compared to properties of concrete prepared by compaction through vibration. With the increase in casting pressure from 25 to 35 MPa, compressive strength and MOE of RAC was increased by 21% and 29%, respectively. It was found that RAC mix exhibited inferior properties (i.e., compressive strength and MOE) compared with NAC mix.