Potential use of stockpiled circulating fluidized bed combustion ashes in controlled low strength material (CLSM) mixture

This paper presents the results of an experimental investigation carried out to evaluate the potential use of stockpiled circulating fluidized bed combustion (CFBC) ashes in developing controlled low strength material (CLSM) in which stockpiled CFBC ash was partially or fully replaced with Class F fly ash. Prior to develop CLSM mixture, basic material characterization of stockpiled CFBC ash was executed to identify the physical, chemical, and mineralogical changes due to aging process of the stockpiled ashes. For CLSM mixture, stockpiled CFBC ash was replaced with five different percentages of Class F fly ash by weight (20%, 40%, 60%, 80%, and 100%). Tests were performed to measure fresh and hardened properties of CLSM mixtures. It was found that the stockpiled CFBC ash can be effectively used in developing CLSM mixtures with restricted use of portland cement and fly ash in the direction of sustainable development.