EFFECT OF FLY ASH ON CAPILLARITY OF SELF-COMPACTING FLY ASH CONCRETE

摘要

The performance of self-compacting concrete (SCC) using fly ash (FA) as cement replacement is investigated. Portland cement (C) was partially replaced with different amount of Fly Ash ranging from 0 to 80%. The binder (C+FA) quantity and water to binder ratio were maintained for all mixes. Properties included workability,capillary water absorption,compressive strength and ultrasonic pulse velocity. Concrete mixes were cured for 56 days in water at 20°C. The results indicate that there is reduction in compressive strength and ultrasonic pulse velocity as the percentage of fly ash as partial replacement of cement increases. However acceptable strength values are achieved at high fly ash replacement levels. Using up to 60% fly ash as replacement of cement did not show greater difference in capillary water absorption suggesting that using fly ash in self-compacting concrete is beneficial. Beyond 80% Fly Ash,the rate of water absorption is higher than the other mixes and this implies serious consequences on durability.