Khảo sát ảnh hưởng của phụ gia Puzolan, cát kết đến cường độ bền nén của đá xi măng

Abstract

In this study, the effects of the puzzolan and sandstone additives on the mechanical proper-ties of the cement have been investigated. The study showed that when the content of sandstone additive gradually replaced puzolan additive in the cement mix at the rate of 0%, 5%, 10%, 15%, 20%, 30% in volume, the normal consistency was about 24.9% - 25.4%, the initial setting time was about 80 - 95 min, the final setting time was about 125 -140 min (This meets the standard requirements of the TCVN 6260:2009). The compressive strength of the hardend cement paste using 20% of sandstone additive was higher (40.5 MPA) than when using the same content of 20% puzzolan additive (40.0 MPA). But if the content of sandstone additive continues to increase up to 30%, the compressive strength of the hardend cement paste is reduced (37.2 MPA) to the value that is lower than the standard of the TCVN 6260: 2009.