Hydration kinetics of ternary slag-limestone cements: Impact of water to binder ratio and curing temperature

Ternary cements are a promising option to further reduce CO₂ emissions and environmental impact from cement production. The current study investigates in detail the impact of water to binder ratio (0.4, 0.5, 0.6) and curing temperature (5, 20, 40 °C) on the hydration kinetics of a ternary cement comprising clinker, slag and limestone in a 50:40:10 mass ratio, respectively. The results show that the water to binder ratio mainly affected the hydration degree of slow reacting phases, such as slag and belite, at later ages. The curing temperature accelerated the hydration of alite to a lesser extent than that of C₃A and slag, which could lead to changes in the hydration reaction sequence at elevated curing temperatures. Elevated temperature curing did not lead to cross-over effects in terms of slag hydration degree at later ages but led to reductions in the portlandite and ettringite levels.