Effect of Industrial Waste on Mechanical and Durability Performance of Concrete

Production of concrete for the construction of structures like, buildings, highways and bridges requires huge amount of cement and aggregates. Consumption of large amount of cement not only affects the natural environment but also strength of concrete. On the other hand, due to heavy concrete production for construction industry causes depletion of natural resources like fine and coarse aggregate in future which motivates this study to be undertaken in order to utilize waste materials in concrete instead of aggregate and cement. This study investigates the properties of concrete by
partially substituting fine aggregate with coal bottom ash (CBA) and cement with fly ash (FA). To achieve this objective, concrete was produced with OPC type-I cement, fine aggregate passing #16 sieve, coarse aggregate of size 10mm, CBA and FA locally available were used. An optimum dosage level of fly ash (15%) was selected from preliminary testing and used together with CBA at various dosage level ranging from 0-35% as fine aggregate replacement. Cubes and cylinders were cast and tested against compressive, tensile, carbonation and sulphate attack test at the end of required curing age. Findings of this study suggest that mechanical performance in terms of compressive and split tensile strength were significantly improved at 25% CBA level which is 52.32 MPa and 3.23 MPa respectively, but not higher than that of conventional concrete mix, it is because the CBA has porous nature and need extra amount of moisture for complete hydration which can be achieved with longer curing durations. Furthermore, the durability of concrete was also found to be improved in terms of carbonation and sulphate attack.