When to use low heat cement – Hydration of cement is an exothermic process that produces large quantity of heat. In mass concrete structures such as dams, retaining walls, bridge abutment, raft etc the rate of dissipation of heat of hydration from the surface is much lower than that generated. It causes rise in temperature inside the concrete mass and may develop thermal and shrinkage cracks. Under this circumstances, the low heat cement or low heat portland cement can be effectively used.
- In low heat cement, ingredients are proportioned in such a way that C3A and C3S are formed in less amount but C2S is formed in increased amount so that C2S and C3S collectively impart the same strength as Ordinary Portland Cement (OPC).
- For low heat cement, the rate of heat evolution is slow initially, so both setting and hardening rates are slow initially. But in the later stage, both rates are faster than the Ordinary Portland Cement (OPC).