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 (۸, ۱۰, and ۱۲ M), various ratios of alkali-activator solution (۱, ۲, and ۳), 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 ۱۲ M and an alkali activator ratio of ۲ show high compressive strength, which is ۷۱.۷۹ N/mm۲. 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 ۷% for ۱ hour and ۱۰% for ۲۴ hours, and density by about ۱.۵%. It is suggested that the optimum mix with ۵۰% copper slag, ۱۰% rubber with pre-treatment for a period of ۱ hour, ۱۲ M NaOH, and alkali activator ratio ۲ provide excellent results among all mixes. In conclusion, the findings indicate that the produced mortar contributes to economic and ecological improvement.

Keywords:

Copper slag , Crumb rubber , density , Strength properties , Water absorption