Effect of sieved coal bottom ash as a sand replacement on the properties of cement concrete

This paper presents the results of an experimental investigation into the effects of sieved coal bottom ash (SCBA) as a replacement for natural sand on the properties of concrete. The compressive strength, split tensile strength, flexural strength and water permeability were studied. Natural sand was replaced with SCBA (0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100% by weight) at a fixed water/cement ratio. The results indicate that there was a decrease in the density and workability of SCBA concrete with an increase in SCBA percentage. It was also found that, compared with a control concrete, the compressive strength, split tensile strength and flexural strength increased when the percentage of SCBA was increased up to 30% and the same properties decreased when the percentage of SCBA was increased beyond 30%. The permeability of SCBA decreased up to 50% replacement and increased beyond 50% replacement.