Abstract
This study was designed to improve the resistance of sulfate attack of blast furnace slag cement by using anhydrite (AH) and lime stone powder (LSP) as a admixture. The early age (7day) hydration product and the porosity of the specimens are investigated for the explanation of the effect of AH replacement, LSP replacement and combined use on blast furnace slag cement against sulfate attack. As a result, the highest resistance against sulfate attack was found at 5% of AH and 20% of LSP replacement ratio in this study. In the case of combined use, high amount of ettringite, and monocarbonate are generated instead of monusulfate. Even more, the pore size was small. Only with replacing the AH, it was not effective for the sulfate attack, even increasing the amount of AH, generating of monosulfate was not restrained. Also only with the replacing of LSP, resistant was not improved, because the amount of ettringite was small, even if the monocarbonate was founded instead of monusulfate. Same tendency was observed with the mortal specimens for sulfate attack test.
