Shear strength characterization and sustainability assessment of coal bottom ash concrete

Abstract

The present study investigated the synergistic influence of coal bottom ash (CBA) on the shear strength of concrete. CBA was milled for 2, 6, and 10 h to form grinded CBA (GCBA). “L” shaped specimens were prepared with 10%–30% GCBA and 25%–50% CBA as alternative of Portland cement and natural fine aggregates. Concrete containing 20% GCBA (grinded for 6 h) and 25% CBA reported the highest shear strength owing to pozzolanic reactiveness and filler action. X-ray diffraction, scanning electron microscopy–energy-dispersive spectroscopy and Fourier transform infrared also supported the experimental outcomes. Well fitted mathematical models were derived followed by optimization using desirability function approach recommending 5.71 h of grinding, 26.27% GCBA, and 36.69% CBA as the optimum amount for its successful utilization in concrete. This approach further leads to significant reduction of about 22% in carbon footprints and eco-costs in comparison to conventional concrete.