CaAl2O4-CaAl4O7 혼입 포틀랜드 시멘트 결합재의 염소이온 고정 특성

초록

This study conducted to understand effects of CA (CaAl2O4) and CA2 (CaAl4O7) ratio on chloride binding ability and compressive strength and pore structure of cement mortar incorporating mixture of CA and CA2. The Portland cement based specimens were mixed with the clinkers CA and CA2, and these calcium aluminate clinker mixture were replaced 0, 5, 10% by weight of cement. After all the test specimens were cured for 28 days under water curing, they were immersed in the distilled water and NaCl solution. As a result, 28 days compressive strength of all specimens was similar, and As the replacement ratio of calcium aluminate clinker in the specimen increased, Friedel’s salt production tended to increase. However, it was dependent on the amount of Al2O3 in the level of 5% replacement and CA ratio in the level of 10% replacement. Through equilibrium isotherm result, it was also indicated that as replacement ratio of calcium aluminate clinker in cement matrix increased, chloride binding capacity was improved, and chloride penetration was suppressed. In this study, the specimen replaced with 10% of the calcium aluminate clinker mixture (CA 39%, CA2 60%) was remarkable to control chloride attack. We figured out necessity to understand optimal CA/CA2 ratio to effectively apply CA2 as a sustainable building material by improving the chloride binding ability in Portland cement based system.

키워드