Which type of cement is used for heavy mass concreting such as dams and bridge foundations?

• A. Portland cement
• B. Expansive cement
• C. Low heat cement
• D. Hydraulic cement

Answer: (C)

In heavy mass concreting, the heat released as cement hydrates can cause large temperature rises inside the structure, leading to thermal cracking if the concrete heats and cools unevenly. Low heat cement is designed to produce less heat during hydration, often by reducing the amount of reactive clinker phases and/or incorporating supplementary cementitious materials. This slower, lower heat release helps keep temperature differences inside the massive pour to a minimum, reducing the risk of cracks in dams and bridge foundations.

Standard Portland cement generates more heat, which isn’t ideal for very large pours. Expansive cement is used to counter shrinkage, not to control heat. Hydraulic cement is a broad category that doesn’t specifically address the heat issue relevant to mass concreting. Therefore, low heat cement is the best choice for these demanding applications.