USING CIRCULATING FLUIDIZED BED FLY ASH TO REPLACE FINE AGGREGATE FOR CLSM

Abstract

This study investigates the potential of fly ash (FA) to replace fine aggregates in concrete as part of a laboratory evaluation of Controlled Low Strength Material (CLSM). After conducting tests on the basic physical properties of FA, fly ash from fluidized bed combustion (CFB) was used to replace fine aggregates in mortar and concrete at replacement ratios of 0, 25, 50, 75, and 100%. The experimental results indicate that both the compressive strength and Ultrasonic Pulse Velocity (UPV) of the concrete samples decreased as the replacement ratio increased. In addition, based on CLSM mixtures with a cement content of 150 kg/m³, where FA replaced fine aggregates at the same ratios (0, 25, 50, 75, and 100%), the results revealed that replacing more than 50% of the fine aggregate with FA significantly reduced key performance parameters such as compressive strength, density, and UPV. Based on these findings, FA shows potential as a substitute for fine aggregates in CLSM; however, the replacement level should not exceed 50%.