Insight to workability, compressive strength and microstructure of lithium slag-steel slag based cement under standard condition

Owing to the industry's quick development, a lot of lithium slag (LS) and steel slag (SS) are produced as industrial waste and dumped outside, polluting the environment and consuming up valuable land resources. In this research, experiments were conducted to determine the reactivity of lithium slag (LS) and steel slag (SS) as Supplementary Cementitious Materials (SCMs). Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) techniques were used to evaluate the microstructure and phase composition of hardened products. Transform Infrared Spectroscopy (FTIR) was accomplished to estimate their chemical functional groups. This investigation revealed that the fluidity and setting time might be controlled by combination of LS and SS. The compressive strength of the cement with addition of L10S10 (cement was replaced with 10% of LS and 10% of SS) showed the highest compressive strength of 48.2 MPa at 28 d within the LS and SS combination groups. The insertion of LS was more beneficial to the long-term hydration process. The addition of 10% LS powder produced substantial hydration products at 28 d. These hydration products are mainly C–S–H gel and Ca(OH)2 (CH)), which was confirmed by FTIR spectra. The results obtained from this research are useful in reducing harmful exposures to environment due to the stockpiling of LS and SS and improving the sustainability of construction using industrial waste products.