Characterization and Use of Industrial Fly Ash

Characterization and Use of Industrial Fly AshSafe & Sustainable Infrastructure

ABOUT THE PROJECT

This project aims to increase the use of fly ash in concrete and substantially reduce greenhouse gas emissions in the construction process.

NOTABLE ACHIEVEMENTS (October 2016)

• Property analysis and characterization has been completed.
• The potential for pelletization of fly ash has emerged as a new opportunity which is being explored.

PROJECT UPDATE (April 2016)

A better understanding the physical properties of fly ash generated from Indian coal-fired power stations in relation to currently used Canadian sources is intended to help producers and users to increase its utilization in concrete and substantially reduce greenhouse gas emissions. In addition, particle size analysis tests are being developed that can be used to evaluate the suitability of Indian fly ash for use as a pozzolan in blended cements or concrete. For example, this research examines the potential role of laser diffraction technique to improve classification of fly ashes. A better understanding for particle size distribution can provide meaningful parameters for setting appropriate particle size specifications for fly ash to help fly ash producers improve consistency and performance of fly ash for use in cement and concrete. In addition, conducting a life cycle assessment (LCA) of concrete containing fly ash is underway for both the Canadian and Indian context. Work currently in-progress is focused on examining the sensitivity of the electricity grid mix, fly ash allocation, and mode and transportation distance of fly ash on environmental impacts.

RESEARCH ABSTRACT

Worldwide, the cement industry is under pressure to reduce greenhouse gas emissions and energy consumption and a number of initiatives have been taken to address these concerns. Industrial by-products (ex. fly ash, slag) have been used as supplementary cementing materials resulting in several benefits, including lowering the environmental impact of concrete. North America and India are large cement consumers as well as producers of fly ash from coal-fired power plants. In North America, reports have shown between 45- 75% of the fly ash produced is reused. However, in India some reports indicate that only 20% of the fly ash is recycled or reused with the remainder being typically disposed of in lagoons, landfills and abandoned quarries. The implications of such waste management practices are serious and potentially disastrous for existing communities as well as for future generations. Therefore, safe, sustainable, and beneficial strategies for utilization of fly ash need to be developed further and encouraged in order to advance the sustainability agenda. This study examines various aspects that need to be examined in order to effectively increasing the use of fly ash in infrastructure and construction. Specifically, the objectives of this research program are to: (i) characterize the properties and variability of coal fly ash and bottom ash generated in targeted Indian communities, (ii) critically examine current (Canadian, American, and Indian) standards and specifications for fly ash and propose updates and modifications if needed, (iii) investigate the properties and performance of concrete containing high volumes of fly ash or bottom ash for potential applications in water transport/storage, wastewater, transportation, and residential infrastructure, (iv) develop performance-based specifications for high volumes of fly ash used as cement replacement and aggregate replacement for appropriate applications relevant to the advancement of the quality of Indian infrastructure, and (v) quantify the life cycle cost associated with the transportation of fly ash across India.

Research focused on advancing concrete materials and manufacturing processes associated with reduced environmental impact is of interest to the Canadian and the Indian construction industry, cement producers, engineers, environmental and material scientists as well as society at large.