2017 Volume 71 Issue 1 Pages 169-176
Recently, the demand for precast concrete have been increased with the object for construction, productivity, quality control and the shortening of a construction period. In addition, the study for compressive strength of fly ash concrete under the steam curing has been investigated. However, the effect of various condition such as, temperature history and curing condition（water curing or air curing）after steam curing on concrete performance has not been clarified. Regarding the Fly ash concrete cured in temperature history, the study of compressive strength under long term curing age has not been enough.
From the background, the relation between the phase composition and compressive strength of Fly ash was investigated in this study. In this study, high early strength cement replacement with Fly ash（named FAHC）was focused. To clear the effect of the replacement of Fly ash for compressive strength under the period early age between long term ages, the phase composition of hardened Fly ash cement paste was measured. Furthermore, in order to evaluate the effect of the various binder types, the compressive strength in FAHC paste was evaluated by Gel/Space ratio using phase compositions. It is clarified that the compressive strength in FAHC paste is a value at the same level as Ordinary Portland cement replacement with Fly ash at early age. Furthermore, Oxygen and chloride ion diffusion coefficient decrease by replacement with Fly ash in FAHC.
