리트벨트법에 의한 혼합재 첨가 보통 포틀랜드 시멘트 중 C3A 수화반응 해석

Due to the revised Korean standard KS L 5201 for Ordinary Portland Cement (OPC), the use of mixed cement has grown from5% to 10%. This study investigates the hydration behavior of C3A, asit is a cement mixture that is more commonly used thangranulated blast furnace slag or limestone alone. Paste samples were prepared with either granulated blast furnace slag or limestonealone. Each sample was compared with the widely used Rietveld method with a cement mixture containing blast furnace slag orlimestone. The hydration behavior of C3A in each OPC sample was assessed and results were analyzed. Granulated blast furnace slagpromotes a high initial level of ettringite, but as the days passed, it promotes an increase in monosulfate, leading to cracks andexpansion due to the penetration of sulfates in the solution. However, when limestone is added to the mixture, a transformation ofettringite to monosulfate occurs in the presence of the CaCO3 in the limestone. It is considered that this produces hemi-carbonate andmono-carbonate and thus maintains the ettringite level.