Fluidity and hydration properties of blended binder of lithium slag and cement

The influence of lithium slag (LS) on the workability and hydration properties of composite cement pastes was investigated. The results show that, with an increase in LS content, the setting times of the composite binder increased, the fluidity gradually decreased and the drying shrinkage deformation was reduced. With the addition of LS, the second exothermic peak occurrence time was greatly delayed and the hydration heat evolution rate and the cumulative heat release both decreased. At later age, LS and calcium hydroxide undergo a secondary hydration reaction, generating hydration products like ettringite and calcium silicate hydrate gels, which fill the pores, improve the pore structure of the composite binder and enhance the compressive strength. In comparison to the control paste, the 28-day strength of the cement–LS paste with 10% LS and 20% LS increased by 3.2% and 5.1%, respectively.