Durability of gamma irradiated polymer-impregnated blended cement pastes

This study is focusing on durability of the neat blended cement paste as well as those of the polymer-impregnated paste towards seawater and various concentrations of magnesium sulfate solutions up to 6 months of curing. The neat blended cement paste was prepared by a partial substitution of ordinary Portland cement with 5% of active rice husk ash (RHA). These samples were cured under tap water for 7 days. A similar paste was impregnated with unsaturated polyester resin (UPE) followed by gamma rays ranging from 10 to 50 kGy. The obtained data indicated that the polymer-impregnated specimens higher values of compressive strength than those of the neat blended cement paste. In addition, the polymer-impregnated blended cement specimens irradiated at a dose of 30 kGy and neat blended cement specimens were immersed in seawater and different concentrations of magnesium sulfate solutions namely, 1%, 3% and 5% up to 6 months. The results showed that the polymer-impregnated blended cement (OPC–RHA–UPE) paste irradiated at a dose of 30 kGy has a good resistance towards sulfate and seawater attack as compared to the neat blended cement (OPC–RHA) paste. These results were confirmed by scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) studies.