This study explored the mechanism of the effect of seawater on tricalcium aluminate (C₃A) hydration. The results showed that seawater retarded C₃A hydration and reduced the reaction degree of C₃A. The co-existence or ion pairing of Ca²⁺ and SO₄²⁻ onto the surface of C₃A poisoning the reactive sites is the main reason for this retardation. Besides, the precipitation of Mg(OH)₂ on the surface of C₃A would prolong the induction period for another 30 min and then consequently decrease the dissolution rate of C₃A hydration. Trace amounts of MgSO₄⁰ and Mg²⁺ present in the alkaline solution had little retardation effect. It was also found that Cl⁻ would preferentially react with C₃A to form Friedel's salt, rather than forming hydroxy-AFm as that in the C₃A-deionized water paste. The direct formation of Friedel's salt resulted in an accumulation of Al³⁺ in solution, which would also hinder the subsequent dissolution of C₃A.

本研究探讨了海水对铝酸三钙 (C ₃ A) 水合作用的作用机制。结果表明，海水延迟Ç ₃甲水化和减少C的反应程度₃ A.共存或Ca的离子配对²⁺和SO ₄ ^2-到C的表面₃中毒的反应位点是主要的这种延迟的原因。此外，Mg(OH) ₂在C ₃ A表面的沉淀会使诱导期再延长30 分钟，从而降低C ₃ A 水合的溶解速率。痕量 MgSO ₄ ⁰和 Mg存在于碱性溶液中的²⁺几乎没有延迟作用。还发现Cl ^-会优先与C ₃ A反应形成弗里德尔盐，而不是像在C ₃ A-去离子水糊状物中那样形成羟基-AFm 。弗里德尔盐的直接形成导致溶液中 Al ³⁺的积累，这也会阻碍 C ₃ A的后续溶解。