What is the primary purpose of the Le Chatelier test?

To detect unsoundness in cement due to the presence of uncombined free lime.

What should be the water content of the cement paste used?

The paste should be prepared with 0.78 times the water required to produce a paste of standard consistency.

How long must the specimen be boiled?

The specimen must be brought to boiling in 25-30 minutes and boiled continuously for exactly 3 hours.

IS 4031 Part 7

: 1988

Methods of Physical Tests for Hydraulic Cement - Part 7: Determination of soundness by Le Chatelier method

CurrentFrequently UsedTesting MethodMaterials Science · Cement

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This standard outlines the testing procedure for determining the soundness of hydraulic cement using the Le Chatelier method, which evaluates the risk of delayed destructive expansion caused by uncombined free lime.

Describes the procedure for determining the soundness of hydraulic cement by the Le Chatelier expansion method.

Quick Reference Values

Le Chatelier mould internal diameter30 mm

Le Chatelier mould height30 mm

Indicator pointer length165 mm

Standard room temperature27 ± 2 °C

Minimum relative humidity90%

Time to reach boiling point25 to 30 minutes

Continuous boiling duration3 hours

Key Formulas

Expansion = L2 - L1 (where L1 is distance between pointers before boiling, L2 is distance after boiling and cooling to room temp)

Practical Notes

Water requirement for the paste preparation is typically 0.78 times the water required for standard consistency (as determined by IS 4031 Part 4).

Lightly oil the mould and glass plates to prevent the cement paste from adhering to the apparatus.

Ensure the water bath has sufficient capacity to keep the specimens completely submerged throughout the 3-hour boiling process.