Evaluation of strength parameters of ultra-fine flyash and nanosilica incorporated High-Performance Concrete

The effect of ultra-fine fly ash (UFA) and nanosilica on the strength properties of High-Performance Concrete are investigated in this study (HPC). Cement was replaced in varying batches with UFA at 0%, 10%, 20% and 30% by weight of cement. Nanosilica was added at a rate of 0 %, 1.5 %, 3.0 % and 4.5 % by weight of the binder. Water-tobinder ratios of 0.3, 0.325, 0.375, 0.4, and 0.425 were used in the mix design. All of the concrete mixes were evaluated for compressive strength at 7, 28, and 90 days, as well as split tensile and flexural strength at 7 and 28 days. Conclusions were drawn by comparing the results with conventional concrete. The HPC with 10% UFA, 3.0% nanosilica, and 0.30 water-to-binder ratio had the best results, with compressive strength gains of 28.24%, 28.11 %, and 31.89 % at 7, 28, and 90 days, respectively. Tensile strength increased by 21.84 percent and 38.56 percent after seven and twenty-eight days, respectively, while flexural strength improved by 39.26 percent and 24.37 percent. Mathematical relationships between cube compressive strength and split tensile strength, as well as flexural strengths, were developed as a result of this research. (c) 2021 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the Global Conference on Recent Advances in Sustainable Materials 2021.