This study focuses on the partial substitution effect of ordinary Portland cement (OPC) by different ratios of waste glass powder (5%, 10%, and 20% by weight of cement) on the performance of blended cement mortars. The hardened blended cement mortars were first cured under tap water for different time intervals 3, 7, 28, and 90 days. However, the effect of addition of 10% styrene‐acrylic ester as well as the influence of different doses of gamma rays on the physico‐chemical and mechanical properties of polymer modified blended cement mortar specimens were discussed. Compressive strength, total porosity, and water absorption percentages were measured. The experimental results showed that the physico‐chemical and mechanical properties of blended cement mortars specimens improved as the waste glass content increases up to 20%. In addition, irradiated SAE blended cement mortar composites containing 20% waste glass showed an enhancement in its properties as compared to neat cement (0%WG content) composites. The results were confirmed by X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy. POLYM. COMPOS., 39:985–996, 2018. © 2016 Society of Plastics Engineers