Question

Which of the following cement contains maximum percentage of dicalcium silicate?

• A. Ordinary Portland Cement
• B. Low Heat Cement
• C. Rapid Hardening Cement
• D. Sulphate Resisting Cement

Answer 1

The correct option is B Low Heat Cement

Low heat cement contains high $C_{2}S$ and low $C_{3}S$ content compared to OPC
( l ) Low Heat Cement:
It is a Portland Cement with low $C_{3}S$ and $C_{3}A$ and high $C_{2}S$ content.
• It is suitable for mass concreting works such as dams due to low heat of hydration.
• Rate of strength development is slow but the ultimate strength is same as the OPC.
(2) Rapid Hardening Cement:
• Also called as high early strength Portland Cement
• Contains high $C_{3}S$ content and less $C_{2}S$ content
• Suitable for road repair works and in structures where load is applied in a short period of time.
• Unsuitable for mass concreting because excessive heat evolution can result in serious cracking.
(3) Sulphate Resisting Cement is a type of Portland Cement in which the amount of tricalcium aluminate $\left(C_{3}A\right)$ is restricted to lower than 5% and $(C_{3}A+C_{4}AF)$ lower than 25%, which reduces the formation of sulphate salts. The reduction of sulphate salts lowers the possibility of sulphate attack on the concrete.
Ordinary Portland Cement - It reacts with silica and it is helpful in development of strength.