γ-C2S 및 MgO를 다량 혼입한 시멘트 페이스트의 CO2 양생에 따른 물성변화

Abstract

본 연구에서는 CO2 양생 효과를 극대화 할 수 있는 γ-C2S와 MgO와 같은 CO2 흡수 물질을 혼입한 시멘트 페이스트의 CO2 양생 효과에 관한 연구를 위하여 W/B를 40%로 설정하고 혼화재료 γ-C2S와 MgO를 90% 다량 치환하여 혼화재료, CO2 양생 유무에 따른 압축강도 측정, 미세 화학분석을 실시하였다. 그 결과 CO2 양생으로 인해Plain의 경우 약 1.08배~1.26배의 압축강도 증가 효과가 나타났으며 γ-C2S와 MgO를 90% 치환한 γ-C2S, MgO실험체의 경우, 각각 14.56배~45.7배, 6.5배~10.37배향상 효과가 나타났다. 이에 따라 미세 화학분석을 실시하여 다량의 CaCO3, MgCO3가 생성된 것을 확인하고 공극감소의 효과를 확인하였다. 따라서 CO2 흡수물질 γ-C2S,MgO를 다량 혼입한 시멘트 페이스트의 CO2 양생에 의한 압축강도 발현효과가 검증됨을 확인할 수 있었다.

Carbonation of concrete causes reduction of pH and subsequently causes steel corrosion for reinforced concrete structure. However, for plain concrete structure or PC product, it can lead to a decrease in porosity, high density, improvement of concrete, shrinkage-compensation. Recently, based on this theory, research of CO2 curing effect has been performed, but it was mainly focused on its effects on compressive strength using only ordinary portland cement. Researches on CO2 curing effect for concrete containing CO2 reactive materials such as γ-C2S, MgO haven’t been investigated. Therefore, this study has performed experiments under water-binder ratio 40%, and the replacement ratios of γ-C2S and MgO were 90%. Micro-chemical analysis, measurement of compressive strength according to admixtures and CO2 curing were investigated. Results from this study revealed that higher strength was measured in case of CO2 curing compared with none CO2 curing for plain specimen indicating difference between 1.08 and 1.26 times, in case of γ-C2S 90, MgO 90 specimen, incorporating high volume replaced as much as 90%, it was proven that when applying CO2 curing, higher strength which has difference between 14.56 and 45.7 times, and between 6.5 and 10.37 times was measured for each specimen compared to none CO2 curing. Through micro-chemical analysis, massive amount of CaCO3, MgCO3 and decrease of porosity were appeared.