Effect of triethanolamine on the initial setting time and hydration behavior of BOFS - cement materials

Triethanolamine (TEA) has been widely used as the chemical admixture to modify the workability of cement-based materials. In order to investigate the effect of triethanolamine (TEA) dosages on the setting time and hydration performance of steel slag-cement composites materials (SSCMs), different dosages of TEA are used to prepare cementitious composites. A range of trials, including microstructural analysis of hydration products, initial setting time, isothermal conduction calorimetry, thermogravimetric analysis and thermodynamic modelling (GEMS) are carried out to investigate the setting time and hydration properties of SSCMs. The results showed that the hydration products of C12A7 phase in steel slag overlapped each other by adding high dosage of TEA (0.5%) and could build a good solidification network. Improving TEA dosages could stimulate the aluminates phase, which could shorten the initial setting time in hydration process. When the amount of triethanolamine increasing to 0.5%, the degree of SSCMs hydration is enhanced substantially. Furthermore, thermodynamic modelling calculations show that with the C12A7 content increases, more C3AH6 and AFm are formed rather than ettringite. These results may contribute to improving the utilization of steel slag and the construction efficiency.