Synergistic effect of waste glass powder and fly ash on some properties of mortar and notably suppressing alkali-silica reaction

In this study the mitigation influence of incorporating waste glass powder (G) and class F fly ash (F) in mortar as partial cement replacement on the alkali-silica reaction (ASR) between reactive aggregate and alkali contents of cement were investigated. Waste G and F replaced cement separately and together on mass basis at 10%, 20%, and 30%. The unit weight (28 days), water absorption, porosity, compressive, and flexural strength tests were conducted at 28- and 90-day water curing time on 40x40x160 mm prismatic hardened samples and flow table test on fresh mortar. There was a slight reduction of the unit weight, an increased workability, and decreased water absorption and porosity; a little reduction of the compressive strength and flexural strength were seen after the tests. In addition, the expansions of mortar were measured up to 90 days. When 14 days expansions were considered according to ASTM C1260, addition of waste G and F separately reduced the expansion that occurred due to ASR. However, the mixture containing 15% waste G and 15% F together (GF-30) exhibited the lowest expansion in the order of 0.02% which was far lower than 0.10%. The higher replacement ratio of waste G and F together and separately caused lower expansion in mortar