Effect of (κ)- and (ι)-Carrageenans on Rheology and Strength Development of Cement-Based Materials

The effect of kappa (kappa)-iota (iota)-carrageenan used in combination with two different types of high-range water reducer (HRWR) on the rheological behavior, hydration kinetics, and strength development of cement-based materials was evaluated. The use of (kappa)-(iota)-carrageenan increased the yield stress, plastic viscosity, rigidity, and structural buildup kinetics of cement suspensions. However, the combined addition of (kappa)-(iota)-carrageenan with HRWR reduced the yield stress and plastic viscosity. Although the addition of (kappa)-(iota)-carrageenan extended the dormant period of cement suspension, (kappa)-(iota)-carrageenan did not significantly affect early-age compressive strength development. Compared to (kappa)-carrageenan, the use of the (kappa)-(iota)-carrageenan combination reduced the dormant period of cement suspensions by approximately 50%, resulting in a 50% increase of compressive strength.

Automated summary

The effect of kappa-iota carrageenan on the rheological behavior, hydration kinetics, and strength development of cement-based materials was investigated. The results showed that the addition of kappa-iota carrageenan increased the flowability and structural stability of cement suspensions. However, when combined with high-range water reducer (HRWR), the effect of kappa-iota carrageenan was reduced. Furthermore, the addition of kappa-iota carrageenan delayed the hardening time of cement suspensions, but had no significant impact on early-age compressive strength development.