Usage of Coal Fly Ash and Bottom Ash from Ash Ponds for Bricks and Precast Concrete Blocks – A Review

Abstract

As larger amounts of coal are burned every day to produce electricity for a growing population, more coal ash is produced and stockpiled in large landfills and ash ponds. The ever-increasing stockpiles of unutilized Coal Fly Ash (CFA) and Bottom Ash (CBA) are a growing health and environmental concern. Studies have shown that communities living near ash ponds are subjected to an increased risk of respiratory illness, and the stockpiles can also potentially cause environmental pollution due to leachate. The potential utilization of CFA and CBA is to use them as natural aggregate substitutes for construction materials such as mortar, bricks and precast concrete. This paper aims to review recent studies on the usage of CFA and CBA in producing brick and precast concrete blocks, the changes in the properties of the CFA or CBA bricks and precast concrete blocks compared to control samples, as well as the effects of seawater intrusion into the concrete mix, which indicate the potential effects of using CFA and CBA stored in coastal ash ponds.