The materials used in this investigation were ordinaryPortland cement (OPC), granulated blast-furnace slag cement (GBFSC) andlimestone (LS). The slag cement containing limestone shows small thermalexpansion and shrinkage coefficient in comparison to neat OPC pastes. This ismainly due to the pozzolanic activity of the granulated slag as well as thefilling effect of limestone. It was found that the partial substitution of slagby 5 wt.% LS improves the compressive strength. As the curing temperatureincreases, the C-S-H phases are deposited within the pore system, which canaccommodate larger amounts of hydration products. This fact leads to relativelyhigh compressive strength values of GBFSC when compared with OPC pastes. As theamount of limestone increases (15 wt.% LS), the compressive strength diminishes.The presence of 15 wt.% limestone changes the morphological shape of C-S-Hcrystals from fibers to crumbled foils with small fibers embedded of Ca(OH)2phase.
