Effect of mineral admixtures on early age properties of high performance concrete

Abstract

Abstract In effect, the early age characteristics of concrete practically determines the performance of concrete during service. While several factors influence the fresh nature of concrete, water-binder (w/b) ratio and admixtures are particularly the most important. In this study, the effect of Nano-silica (NS) and fly ash on early strength characteristics of an M50 grade of high performance concrete was investigated. The contents of fly ash and Nano silica were used in varying proportions, from 28% to 32% and 1.0% to 2%, respectively, by weight of cement in the mix. Natural river sand was partially replaced by manufactured sand (M-sand) at 0%, 50% and 100% levels. Concrete mixture was achieved at 0.39 water/binder ratio. The workability and setting time of fresh concrete, by slump and penetration resistance tests, respectively, were determined as per ASTM C-403. The strength development at the early age was investigated and compared with that of the control concrete, based on tests on cube and cylinder specimens. Based on the obtained results, the early age strength of HPC containing NS was improved than the results obtained using the IS: 456-2000 code recommended models.