A Review of C3A Hydration with Admixtures and Its Role in Sulfate Attack

Abstract

Abstract Mineralogical and morphological characteristics of cementitious materials at the early stage of hydration primarily govern the performance and durability characteristics of concrete. Tricalcium aluminate (C3A) is one of the important phases of cement that primarily controls the initial setting. It plays a crucial role in producing tricalcium silicate in the manufacturing of portland cement, which is the dominant phase and is mostly responsible for strengthening and hardening the cementitious system. This necessitates a comprehensive review of C3A hydration, which provides the beneficial role of C3A at the early stage of hydration, and understanding the influence of other admixtures in a modified cementitious system. To this end, this paper presents a critical review of the hydration of C3A and its role during the early stage of hydration. Understanding the reaction mechanism in the presence of various forms of calcium sulfate through different proposed theories has also been critically reviewed. Additionally, admixtures such as accelerators, retarders, water-reducing dispersants, superplasticizers, and parameters like water/solid ratio on C3A grain, which affect the setting time and rheology, have also been thoroughly presented. Furthermore, the role of C3A in the formation of secondary ettringite and the factors that affect the durability of concrete are focused on.