Hydration of cement — role of triethanolamine

Following addition of 0.1, 0.25, 0.35, 0.5 and 1.0 per cent triethanolamine, studies have been made of the hydration and hardening characteristics of (a) tricalcium aluminate, (b) tricalcium aluminate + gypsum, (c) tricalcium silicate, (d) dicalcium silicate, and (e) portland cement. Triethanolamine (TEA) accelerated the hydration of 3CaO.Al₂O₃ and 3CaO.Al₂O₃-CaSO₄.2H₂O systems and extended the induction period of the hydration of 3CaO.SiO₂. In portland cement paste TEA decreased the strength at all ages and setting characteristics were drastically altered, especially at higher TEA contents. Evidence was obtained also of the formation of a complex of TEA with the hydrating silicate phase.