Which cement type is commonly used to reduce heat of hydration in large pours?

• A. Type I cement
• B. Type III cement
• C. Type II cement
• D. Portland cement with pozzolanic addition

Answer: (C)

Heat of hydration is the heat released as cement hydrates, and in large pours that heat can build up inside the mass, risking thermal cracking as the concrete cools unevenly. Type II cement is designed to develop strength more slowly and generate less heat than ordinary Type I cement, making it the practical choice for large pours where controlling temperature rise is important. Type III cement hydrates quickly and releases more heat, which defeats the goal here. While Portland cement with a pozzolanic addition can also reduce heat, that option isn’t a single cement type and isn’t the standard specification used for large-volume pours; Type II is the typical recommendation to reduce heat of hydration.