Improvement of the Hydration Kinetics of High Ferrite Cement: Synergic Effect of Gypsum and C<sub>3</sub>S–C<sub>4</sub>AF Systems
Kechang Zhang, Peiliang Shen, Lu Yang, Meijuan Rao, Fazhou Wang
Abstract
High ferrite cement (HFC) has attracted widespread attention due to the low carbon footprint and energy consumption. Gypsum, one of the essential components in Portland cement, plays a crucial role in the performance development of the matrix. However, the effect of gypsum on the performance evolution of HFC is obscure and unpredictable owing to the transformation of mineral phase composition including C4AF and C3S. Understanding the effect of gypsum is of great significance to further optimize the performance development and promote the application of HFC. This work was designed to investigate the influence of gypsum on the hydration kinetics of mineral phases and early performance development of HFC. Based on the experiment results, the underlying mechanism was explored and the role of gypsum in HFC can be divided into three aspects: (1) it changes the dissolution–precipitation process of C4AF and the reaction environment (pH value); (2) it relieves the inhibition effect of Al3+ ions from C4AF on the hydration of C3S; and (3) it enhances the hydration kinetics of C3S and the formation of ettringite. As a result, the early performance development of HFC was improved evidently and the role of gypsum revealed in our work is of great significance to promote the sustainable development of HFC.