Enhancement of Early Age Strength of Activated Steel By-Products

All factories produce by-products and waste that are needed to be recycled or reused in other industries to keep the environment sustainable for future generations. Also, one of the human efforts to reduce the built emission environment is the use of types of cement whose production produces less carbon dioxide such as by-products activated with alkali to move toward low carbon cement and net zero concrete. As a by-product of steel factories, different types of slags are worthy to be studied to be used in low-carbon cement production. However, different studies have shown the low early-age strength of these materials. In this study, ground granulated blast furnace slag (GGBS) was replaced with different slag as by-products of one steel factory and activated with different [OH−]/M activator systems to study which works better to enhance early-age strength in different types of slags. The effect of further treatment on different slag such as calcination was considered as well. Flow tests, compressive strength tests, and flexural strength tests were conducted to evaluate the fresh and hardened properties of the final products mortar. This paper shows that the addition of mineral additives brings a positive effect by enhancing the early age strength in the cases where main mineral is lacking in the precursors’ composition.