Effect of Lightweight Aggregates on early-age behavior of High Performance Concrete

Laboratory experiments were conducted to investigate the effects of locally available natural lightweight aggregates (LWA's) on volume changes and mechanical properties of highperformance concrete (HPC). The normal aggregates fraction of high-performance concrete was replaced with fine and coarse LWA's at three different replacement levels, 5%, 10% and 20% by volume. The test results indicated a significant reduction in the autogenous shrinkage of highperformance concrete at 56 days without a corresponding considerable reduction in compressive strength of the same concretes. The test results have also shown that up to 20% volume fraction of coarse LWA's could be used for mitigating the volume changes of HPC with a slight reduction in compressive and splitting tensile strengths, and elastic modulus. Therefore, this investigation recommends the use of locally available natural LWA's as a viable curing technique for minimizing the volume changes and risk of cracking of HPC's without compromising their mechanical properties.