The Effects of Al 3+ on the Hydration of Hybrid C 4 AF and β‐C 2 S Clinkers: An Ab Initio Molecul
Zichao Li, Zhongyong Zhang, Huangjie Zou, Jiayu Yue, Wei Chen, Neng LiABSTRACT
The low‐temperature calcination brings environmental benefits by producing low‐carbon clinker with tetracalcium aluminoferrite (C 4 AF) and dicalcium silicate (C 2 S); this mineral composition alteration causes complex hydration behaviors. The microscopic mechanism of their synergistic hydration remains unclear, which limits further optimization of this low‐carbon cement. In this work, we construct a solid‐liquid interface model for β‐C 2 S in various systems (pure H 2 O, Al 3+ , Ca 2+ , and Al 3+ ‐Ca 2+ system) to investigate how the ionic environment arising from the fast dissolution of C 4 AF affects the β‐C 2 S hydration process. The results demonstrate that the dissolved Ca 2+ and Al 3+ ions exhibit an antagonistic effect by combining well‐defined density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations. The Al 3+ ion inhibits the degree of surface hydroxylation by occupying surface calcium sites and adsorbing free hydroxyl groups, while the Ca 2+ ion enhances proton transfer activity and increases the interface dynamics. Ultimately, the inhibitory effect of Al 3+ dominates, significantly suppressing the initial hydration of β‐C 2 S. This study reveals the role of the interfacial ionic environment during the synergistic hydration of C 4 AF and β‐C 2 S, providing a theoretical foundation for designing sustainable cement.