Sustainable utilization of aluminum waste in geopolymer concrete: Influence of alkaline activation on microstructure and mechanical properties

The study investigated the impact of incorporating varying quantities of aluminum waste (Al-waste) and slag on the properties of geopolymer concrete, specifically by altering the molarity (M) and Al-waste. To achieve this objective, slag was substituted with fly ash at 0, 5, 10, and 20% concentrations. Furthermore, oven and ambient curing were compared. The impact of M was subsequently examined. The study also includes the examination of penetrability, time of setting, compressive strength tests, splitting tensile tests, and flexural strength tests. An increase in M was found to result in a decrease in the penetrability of the mixture. The findings indicated a negative correlation between the slump values and both the M and Al-waste ratios, and a rise in both factors led to a drop in slump values. Although Al-waste had improved at the time of setting, M still had a substantial impact. Although high M enhanced the mechanical strength, it had a significant negative influence on the setting time and penetrability. This investigation demonstrated that Al-waste had a slight negative influence on the mechanical strength and penetrability. In addition, scanning electron microscopy, thermal gravimetric analysis, and energy dispersive X-ray examination were carried out.