건설재료시공학연구실

Building material & construction lab.

This study focused on the quick initial setting time and the expansion strain that occurs during the early aging of a-calcium sulfate hemihydrate(aHH) and examined the setting, compresive strength, and shrinkge stratin of aHH-replaced cement mortar. The results show that the initial setting time significantly decreased with an increase in the aHH replacement ratio. Drastic occurrence of ettringite was observed early in the aging of cement mortar when aHH was substituted into the cemen; however, the ettringites was not converted to monosulfate with increasing age and thu was not favorable for the development of the compressive strength. When aHH was substituted into cement, using portland blast furnace slag cement(PSC) was more adventageous than using ordinary porltland cement(OPC) for the development o the compssive strength. Meanwhile, the expansion of early age aJHH can decrease the shinkae strain of cement mortar. The generation of ettringite is more effective when aHH is substituted into PSC than into OPC and is thus more effective in suppressing the shrinkage strain.

https://doi.org/10.3390/ma12010163