Insights into cementitious materials: exploring atomic structures and interactions

Understanding cement at the atomic level is essential for optimizing its performance, durability, and sustainability. This review explores the atomic structure and defects of key cement phases—C-S-H, C₃S, C₂S, C₃A, and C₄AF—and their impact on hydration reactions and phase formation. Calcium silicate hydrate (C-S-H), the primary hydration product, is examined for its amorphous structure, which governs strength and durability. Structural defects, including vacancies and dislocations in cement phases, influence hydration kinetics and mechanical properties. Interactions at the atomic scale, such as hydration reactions driven by water molecules and the formation of C-S-H gel, are discussed alongside the role of temperature and pressure in accelerating or decelerating these processes. Insights into atomic arrangements, defects, and environmental conditions provide pathways to improve cement formulations, enhance durability, and reduce environmental impact. This comprehensive review deepens the understanding of cement's fundamental behaviour, enabling advancements in sustainable and high-performance cementitious materials.