Effect of lime and ferrochrome ash (FA) as partial replacement of cement on strength, ultrasonic pulse velocity and permeability of concrete

Ferrochrome ash (FA) is a waste material obtained from the gas cleaning plant of a ferrochromium industry. This paper manifests the results of experimental investigations carried out to study the feasibility of using FA in concrete making as partial replacement of ordinary Portland cement (OPC). OPC was replaced by FA in four different substitution rates (10%, 20%, 30% and 40%) and 7% lime. Effect of lime and FA on compressive strength, splitting tensile strength, modulus of elasticity, ultrasonic pulse velocity and water permeability was investigated. Test results revealed that there is a significant development in early age strength due to inclusion of lime and FA. Properties of concrete containing 40% FA and 7% lime replacing 47% OPC was relatively close to control concrete at the age of 28 days. Improvement in strength and durability properties was also observed at later age in concrete, containing lime and FA. It was concluded FA up to 40% with lime 7% can be effectively utilised in concrete preparation without sacrificing or even improving the performance of concrete. Improvement in engineering properties of concrete containing FA and lime is confirmed by petrography examination.