Properties of Cement Pastes Doped with Very High Amounts of Ground Granulated Blast-furnace Slag

In the current work, the properties of cement pastes doped with high amounts of ground granulated blast-furnace slag (HVS) were investigated. Portland cement (PC) was substituted with ground granulated blast-furnace slag (donated as slag) at very high amounts of 85%, 90%, 95% and 100%, by weight. PC paste without any content of slag was used as a reference. Some fresh and hardened properties such as workability, density, compressive strength up to 56 days, pH value and drying shrinkage up to 200 days were measured. The various phases formed were identified using X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The microstructure of the formed hydration products was determined by scanning electron microscopy (SEM). The results indicated that HVS has higher workability and higher drying shrinkage beyond 60 days. On the other hand, HVS has lower pH, density and compressive strength.