Oymael, S.2024-09-182024-09-1820070208-189X1736-7492https://hdl.handle.net/20.500.12483/13792Sulphates usually affect calcium aluminates in cements. Sulphate ions might have negative effects on cement hydration and it would be a reason of decrease in cement strength. In this study, the effects of Na2SO4 solution on the concretes made from OPC with oil shale ash (OSA) addition (0, 15 and 30%) were investigated Concretes with 15% OSA gave the lowest value of Length Change Factor (LCF). Addition of an optimum amount of super-plasticizer increases positive properties of the concrete with 15% OSA addition, binds free Ca(OH)(2) in OPC, makes its composition more effective, prevents massive alkali-aggregates reactions showing that this addition rate is proper.eninfo:eu-repo/semantics/closedAccessOil-Shale AshCementResistanceArticle2445615712-s2.0-38349116001Q2WOS:000251862000007Q2