A critical review of the potential for fly ash utilisation in construction-specific applications in India

Abstract

In India, coal-fired power plants produce about 196 million tonnes of fly ash annually. The management of fly ash has thus been a matter of concern given the requirement of the large area of land for its disposal and potential of causing pollution of air and water. Various initiatives have been taken in the country to promote safe utilisation of fly ash. But despite these initiatives, the optimal utilisation is yet to be achieved. Most of the existing literature is related to forecasting the utilisation of fly ash in different modes and accordingly presents the promising applica-tions, but the latent utilisation potential of applications is not yet explored. In this paper, the potential of fly ash utilisation in various construction-specific applications, i.e., cement, concrete, brick, and blocks, has been estimated through a simple framework. The study reveals that although cement is one of the most prominent applications where fly ash has been significantly utilised, it reached its threshold limit of utilisation. The scope of utilisation of fly ash in cement in the future is limited only to the extent of the rate of increase in cement consumption. The potential of fly ash utilisation in concrete is significantly higher, as the projected growth rate of ready-mix concrete (RMC) is moving upwards. However, this increased percentage of RMC will not impact much on overall fly ash utilisation as this will only balance out the share percentage of overall cement requirement. In this study, the bricks/ blocks emerged out to be the application having a maximum consumption potential. This study further explores the reasons behind the sluggish performance of fly ash bricks and blocks in the market and suggests strategies for policy-level interventions that can accelerate the process of successful commercialisation.