Cement Chemistry
CHLORIDE ION RESISTANCE IN HIGH ALITE CEMENT - FLY ASH - LIMESTONE POWDER SYSTEM
2018 Volume 72 Issue 1 Pages 63-69
Details
2018 Volume 72 Issue 1 Pages 63-69
It was reported that the high alite cement - fly ash - lime stone powder system（AFC）is effective for development of early age strength of fly ash cement. In this experiment, the temperature dependence of hydration reaction and chloride ion resistance of AFC were investigated. As a result of examination, fly ash reacted at room temperature after 28 days of age but did not react at low temperature. And AFC showed high C3S reaction ratio even at low temperature. It is thought that the cause of the increase in C3S reaction ratio of AFC is an increase in the surface area of cement and the filler effect by SCMs. Because the reaction of fly ash is suppressed at low temperature, AFC with high C3S conversion rate is considered to be advantageous for use at lower temperatures than current fly ash cement B type（FB）. Also, the depth of penetration of chloride ions in AFC was shallower than that of ordinary cement（N）, which was comparable to that of FB. One of the reasons for this was chloride ion fixation by the AFm phase. Based on the results of the experiments, AFC is considered to have higher Chloride ion resistance than N.
