The effect of coal bottom ash (CBA) on mechanical and durability characteristics of concrete

Abstract

The present paper would contribute to the efforts being made in the field of concrete technology towards development of concretes possessing good strength and durability properties along with economic and ecological advantage. In the present study it was found that with increase in amount of coal bottom ash, standard consistency, initial and final setting time increase at the same time workability of concrete decreases. Early age strength is less for bottom ash concrete compare to control mix, but as the age increases they show good improvement in strength due to pozzalanic reaction. Optimum dosage is observed to be 10% Grinded Bottom Ash (GBA) which shows about 14 % more strength compared to control mix at 56 days. Also 20% replacement by GBA gives results comparable to control concrete. GBA concrete shows more resistance to acid attack compared to Original Bottom Ash (OBA). Mix M7 with 30 % replacement by GBA shows highest resistance to acid attack. With the increase in amount of bottom ash water absorption capacity of concrete increases, also as the age increases for all the mix water absorption capacity decreases. It was also found that at optimum dosage i.e at 10% replacement of cement with GBA it is also economical and also less amount of CO2 is emitted that mean it is also environmental friendly compared to control mix.