What is the main purpose of Low Heat Portland Cement?

To reduce the heat generated during hydration, making it suitable for mass concrete structures to prevent thermal cracking (Clause 0.2).

What is the maximum heat of hydration allowed at 28 days?

The heat of hydration must not exceed 314 J/g (75 cal/g) at 28 days (Table 2).

What is the minimum 28-day compressive strength for this cement?

The minimum average compressive strength of three mortar cubes is 35 MPa at 28 days (Table 2).

How does its initial setting time compare to OPC?

The minimum initial setting time is 60 minutes, which is longer than the 30-minute minimum for OPC (IS 269), providing more time for placing large volumes of concrete (Table 2).

IS 8047

: 1989

Low Heat Portland Cement - Specification

CurrentSpecializedSpecificationMaterials Science · Cement

Archive.org BIS Portal Google

This standard specifies the requirements for the manufacture, chemical composition, and physical properties of Low Heat Portland Cement. It is intended for use in mass concrete structures where controlling the heat of hydration is critical to prevent thermal cracking, such as in dams and large foundations. The code sets limits for heat generation, strength development, setting times, and soundness.

Specifies requirements for low heat portland cement, suitable for mass concrete structures to minimize thermal cracking.

Quick Reference Values

Maximum Heat of Hydration at 7 days272 J/g

Maximum Heat of Hydration at 28 days314 J/g

Minimum Compressive Strength at 3 days10 MPa

Minimum Compressive Strength at 7 days16 MPa

Minimum Compressive Strength at 28 days35 MPa

Minimum Initial Setting Time60 minutes

Maximum Final Setting Time600 minutes

Maximum Soundness (Le Chatelier)10 mm

Minimum Specific Surface (Fineness)320 m²/kg

Practical Notes

Primarily used for mass concrete pours (e.g., dams, large raft foundations) to control temperature rise and prevent thermal cracking.

Gains strength more slowly than Ordinary Portland Cement (OPC), so formwork removal times may need to be extended.

The slower setting time provides a larger window for placing and compacting large volumes of concrete.