Original paper(Vol.48 No.8 pp.843)

Effect of the quality and replacing ratio of fly ash on the property of self-compacting concrete

Mitsuiwa Yoshitaka; Togawa Kazuo; Nakamoto Junji

Abstract:In order to use fly ash being discharged from the boilers of a coal fired in thermal power station effectively, the authors aimed at self-compacting concrete using high-volume fly ash. However, the qualities of fly ash vary in each of the power station. This study shows the effects that the replacing ratio, the qualities and the specific surface area have on the fluidity, the setting time and the carbonation depth about self-compacting concrete including fly ash. The results obtained are as follows: The fluidity is improved with the decrease of the specific surface area of fly ash. The setting time is increased with the increment of the specific surface area of fly ash. The carbonation depth of self-compacting concrete is very susceptible to the replacing ratio of fly ash. And the effect that the specific surface area of fly ash has on the carbonation depth of self-compacting concrete is small.

Key Words:fly ash, water retaining ratio, modulus of deformation, specific surface area, setting time, carbonation depth