2022 Volume 76 Issue 1 Pages 202-210
The purpose of this study was to change the composition and internal structure of C-S-H, which is the main hydration product in the hardened cement, and to clarify the effect on the linear expansion coefficient of the hardened cement. After mixing with fly ash and crystallization by high-temperature and high-pressure curing, the void structure of the hardened cement was changed to obtain the coefficient of linear expansion and the amount of change in relative humidity. It was clarified that the values of the coefficient of linear expansion and the relative humidity change increased on the high humidity side due to the mixing of fly ash, which is due to the increase in the specific surface area of the solid phase due to the decrease in the C/S ratio. In addition, the formation of tobermorite, the disappearance of voids of 0.1 to 1.0μm, and the decrease in the coefficient of linear expansion were confirmed in the test specimens with a fly ash replacement rate of 45％ that had been subjected to high-temperature and high-pressure curing.
