C2S (Dicalcium Silicate)
Belite — the slow-reacting silicate phase in OPC. C2S contributes mainly to long-term strength beyond 28 days, with low heat generation.
C2S forms 15-30% of clinker. Its slow hydration is well-suited for mass concrete and durability-critical structures where late strength matters more than early strength.
The chemical reaction between cement and water that produces hardened cementitious paste. Hydration generates heat and the binding C-S-H gel that gives concrete its strength.
Alite — the most abundant phase in OPC and the principal contributor to early strength gain. C3S hydrates rapidly to form C-S-H gel and calcium hydroxide.
The heat released as cement reacts with water. Important for thermal control in mass concrete to avoid cracking from temperature gradients.