Le chatelier Apparatus

Procedure:

• i) Before commencing setting time test, do the consistency test to obtain the water required to give the paste normal consistency (P).
• ii) Prepare a paste by adding 0.78 times the water required to give a paste of standard consistency (i.e. 0.78P).
• iii) Lightly oil the Le- chatelier mould and place it on a lightly oiled glass sheet
• iv) Fill the mould with the prepared cement paste. In the process of filling the mould keep the edge of the mould gently together.
• v) Cover the mould with another piece of lightly oiled glass sheet; place a small weight on this covering glass sheet.
• vi) Submerge the whole assembly in water at a temperature of 27 ± 20 C and keep there for 24 hours.
• vii) Remove the whole assembly from water bath and measure the distance separating the indicator points to the nearest 0.5 mm (L1).
• viii) Again submerge the whole assembly in water bath and bring the temperature of water bath to boiling temperature in 25 to 30 minutes. Keep it at boiling temperature for a period of 3 hours.
• ix) After completion of 3 hours, allow the temperature of the water bath to cool down to room temperature and remove the whole assembly from the water bath.
• x) Measure the distance between the two indicator points to the nearest 0.5 mm (L2).

Uses : This test is used for to find the soundness of cement.