What is the main advantage of using Low-Heat Portland Cement?

Its low rate of heat generation reduces the temperature rise in mass concrete, minimizing the risk of thermal cracking.

What is the maximum heat of hydration allowed at 7 days?

272 J/g (or 65 cal/g) as per Table 2.

How does its early strength compare to Ordinary Portland Cement (OPC)?

It has a lower early strength. Minimum 3-day strength is 10 MPa, compared to 16 MPa for 33 Grade OPC (IS 269).

What is the minimum initial setting time for this cement?

60 minutes, which is double the 30-minute minimum for OPC, allowing for longer handling time (Table 2).

IS 12600

: 1989

Low-heat Portland cement – Specification

CurrentSpecializedSpecificationBIMMaterials Science · Cement, Concrete, Aggregates and RCC

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This standard specifies the manufacturing, chemical, and physical requirements for Low-Heat Portland Cement. This cement is intended for use in mass concrete structures like dams, large foundations, and bridge abutments to control temperature rise during hydration, thus minimizing thermal cracking.

Low-heat Portland cement – Specification

Quick Reference Values

Max. Heat of Hydration (7 days)272 J/g

Max. Heat of Hydration (28 days)314 J/g

Min. Compressive Strength (3 days)10 MPa

Min. Compressive Strength (7 days)16 MPa

Min. Compressive Strength (28 days)33 MPa

Min. Initial Setting Time60 minutes

Max. Final Setting Time600 minutes

Max. Expansion (Le Chatelier)10 mm

Practical Notes

Due to its lower rate of early strength gain compared to OPC, formwork striking times must be extended. This should be factored into the construction schedule.

This cement is not suitable for general construction or applications requiring high early strength, such as precast elements or cold weather concreting.

The primary benefit is controlling thermal gradients in thick concrete sections, making it ideal for mass pours.