Evaluation of physical and thermal properties of coal combustion residue blended concrete for energy efficient building application in India

Abstract

ABSTRACT At the backdrop of energy conservation efforts in building sector, this research paper presents a passive approach by producing less heat conducting concrete with the inclusion of coal combustion residue (bottom ash) as a substitute to conventional sand and using low embodied energy cement in the mix. The constituent phases and other physical and chemical parameters of both sand and bottom ash were evaluated. Three different sets of concrete mixes were prepared by following IS 456 code provisions, and the compressive strength, apparent porosity, bulk density and the thermal conductivity parameters of each mix set were evaluated. The reducing trend was observed in thermal conductivity and compressive strength parameters of concrete mixes against the increasing percentage of sand replacement by coal bottom ash. Reduction to the tune of around 25% in the thermal transmittance value (U-value) was observed while comparison was made between conventional concrete roof and bottom ash blended concrete roof with identical features. Coal combustion residue blended concrete could be applied for sustainable and energy efficient building construction for lowering cooling demand without any additional capital investment and also saving sand from faster depletion than its renewal rate.