Soundness of cement is determined by Le-Chatelier method as per IS: 4031 (Part 3) – 1988. Apparatus – The apparatus for conducting the Le-Chatelier test should conform to IS: 5514 – 1969. Balance, whose permissible variation at a load of 1000g should be +1.0g and Water bath.
Procedure to determine soundness of cement
- Place the mould on a glass sheet and fill it with the cement paste formed by gauging cement with 0.78 times the water required to give a paste of standard consistency.
- Cover the mould with another piece of glass sheet, place a small weight on this covering glass sheet and immediately submerge the whole assembly in water at a temperature of 27 ± 2oC and keep it there for 24hrs.
- Measure the distance separating the indicator points to the nearest 0.5mm (say d1 ).
- Submerge the mould again in water at the temperature prescribed above. Bring the water to boiling point in 25 to 30 minutes and keep it boiling for 3hrs.
- Remove the mould from the water, allow it to cool and measure the distance between the indicator points (say d2 ).
- (d2 – d1 ) represents the expansion of cement.