Effect of aluminum sulfate alkali-free liquid accelerator with compound alkanol lamine on the hydration processes of Portland cement

Abstract

Aluminum sulfate alkali-free liquid accelerator is a kind of shotcrete admixture used in the construction of tunnels and culverts. In order to investigate the influence of alkanol amine in aluminum sulfate alkali-free liquid accelerator on cement hydration and strength, the different proportion of triethanolamine (TEA) and triisopropanolamine (TIPA) mixtures were added to aluminum sulfate alkali-free liquid accelerator. The mortar strength was measured by universal testing machine, and the hydration products were analyzed by XRD SEM and thermogravimetric analysis. The results show that TEA can promote the hydration of C3A to form ettringite (AFt) and improve the early strength of cement, and TIPA can promote the hydration of ferrite phase, improve the degree of hydration, and promote the later strength of cement. The synergistic effect of TEA and TIPA in proper proportion can improve both the early strength and late strength of cement at all ages.