A study on the mechanical properties of alkali activated ground granulated blast furnace slag and fly ash concrete

Abstract

Alkali activated concrete (AAC) is one concrete which is made without cement. As sustainable construction is gaining interest, this alkali activated concrete is a better option for conventional cement concrete. Concrete is the most used commodity second only to water with a global Carbon emission of 5%. The evaluation of strength under compression of alkali activated fly ash and ground granulated blast furnace slag concrete, was carried out in this study. The evaluation of compressive strength depending on the method of curing is also studied. In this study Ground Granulated Blast Furnace Slag (GGBFS) and fly ash are used as the pre-cursor materials. These two materials are used in varying proportions and are activated using sodium hydroxide and sodium silicate solutions of varying proportions, after which the strength properties of alkali activated concrete are studied under two methods of curing i.e., water curing and ambient temperature curing. When the results obtained for water curing and curing at ambient temperature were compared the later yields good results. So, the curing at ambient temperature can be preferred over water curing. When GGBFS alone was used as a pre-cursor material the results show higher compressive strength can be achieved in comparison to the specimens having both GGBFS and Fly ash as pre-cursor materials. With increasing proportions of fly ash and decreased GGBFS content, the decrease in compressive strength was witnessed. Also, the specimens kept under water curing and the specimens cured under ambient temperature are compared and found that the later yields higher compressive strength.