Impact on Mechanical and Durable Properties of Rubber and Copper Slag-based Geo-polymer Mortar using Various Sodium Hydroxide Molarities and Proportions of Alkali Activator Solutions

The efficiency of geo-polymer mortar is analyzed by replacing fine aggregates with different ratios of copper slag and crumb rubber. Properties such as flow value, setting time, strengthening properties, density, and water absorption are studied for different factors, i.e. molarities of sodium hydroxide (8, 10, and 12 M), various ratios of alkali-activator solution (1, 2, and 3), and the effect of pre-treating rubber. The results indicate that the increase in molarity increases the compressive strength, setting time, and flow value of mortar. It is observed that NaOH of 12 M and an alkali activator ratio of 2 show high compressive strength, which is 71.79 N/mm2. The rubber treated with alkali improves the bonding between the binder and the rubber, which leads to an increase in the material’s strength by 7% for 1 hour and 10% for 24 hours, and density by about 1.5%. It is suggested that the optimum mix with 50% copper slag, 10% rubber with pre-treatment for a period of 1 hour, 12 M NaOH, and alkali activator ratio 2 provide excellent results among all mixes. In conclusion, the findings indicate that the produced mortar contributes to economic and ecological improvement.