Effect of quarry rock dust on the flexural strength of concrete

Abstract

The effect of quarry dust on the flexural strength of concrete has been experimentally studied and reported in this paper. Concrete used was prepared by replacing 25% and 100% of sand by weight with quarry dust. Also, conventional sand concrete was prepared as reference concrete for comparison. 100mm cube and 100×100×500mm plain beam specimens were prepared using concrete strengths ranging from 25N/mm2 to 47N/mm2 for the three replacement levels of 0%, 25% and 100% to obtain the compressive and flexural strengths respectively at 28days. From the results, it was observed that the flexural strength of concrete with 25% and 100% quarry dust were respectively 2% and 4.3% higher compared with concrete with no quarry dust. By carrying out regression analysis, empirical formulas in the form y=axb were obtained for concrete with quarry dust. The equations were compared with formulas proposed by ACI, BS, IS codes of practice for estimating the flexural strength using the compressive strength of concrete. It was found that incorporating quarry dust in concrete improves its flexural strength.