A Critical Review of the Potential for Fly Ash Utilisation in Construction-Specific Applications in India

Abstract

<jats:p>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 applications, 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.</jats:p>

Transformation of Waste Coal Fly Ash into Zeolites for Environmental Applications

“…Restogi et al have studied the potential to utilize fly ash in the field of different construction area and came out with the results for the fly ash utilization with the projected level until 2030. The study revealed that concrete and cement sectors have reached their threshold limit with accommodating around 35 to 40% of total fly ash generation in the forthcoming years, while the sectors of bricks and blocks are found to be the most potential mode for the fly ash utilization, with the capacity to accommodate all unutilized fly ash remaining during the year along with the potential to utilize the legacy ash within the next 15 to 20 years [17].…”

Next-generation, affordable SO2 abatement for coal-fired power generation - A comparison of limestone-based wet flue gas desulphurization and Sulfacid® technologies for Medupi power station

“…The venturi quench solution that contains PM and heavy metals is drawn off regularly for liquid/solid separation. The dewatered solids could be disposed or potentially utilized in construction materials (Rastogi and Kumar Paul, 2020). The separated liquid is further treated in a liquid waste treatment process, after which most of the liquid is returned to the venturi quench while a small stream is disposed.…”

Field Investigation on Complete Replacement of Granular Subbase with Flyash and Blast Furnace Slag in Flexible Pavement

“…In FY 2020-21, India produced 232 million tons of FA with a utilization rate of 92% [1]. According to Rastogi and Paul, approximately 1400 million tons of legacy FA lay unutilized in India [2]. India, the third-largest steel producer worldwide, generated about 40 million tons of BFS between 2017 and 2018 [3].…”