LimsPulse
Construction materials testing

Le Chatelier Soundness Apparatus

A split brass cylinder with two long indicator arms that magnifies the expansion of a cement paste after boiling. It checks that cement will not expand and crack after it has set (soundness).

  • Cement manufacturing
  • Construction materials testing
  • Ready-mix concrete
  • Academic labs
Illustration of Le Chatelier Soundness Apparatus
Follow your site SOP
This is a typical operating sequence for learning. Your instrument model and approved SOP take precedence.
STAGE 1

Before you start

  1. 1Inspect each mould: the indicators must be straight and the slit must close fully when unloaded.
  2. 2Check the mould's elasticity record is in date (if your SOP includes it).
  3. 3Lightly oil the mould and glass plates.
  4. 4Find the standard consistency (P) of the cement first.
  • Do not use a mould whose indicators have been bent and straightened; the magnification will be wrong.
STAGE 2

Preparing the specimen

  1. 1Gauge the cement with 0.78 P water within the specified gauging time.
  2. 2Place the mould on a glass plate and fill it with paste, holding the slit closed with your fingers or a rubber band.
  3. 3Cover with the top glass plate and place the small weight on it.
  4. 4Submerge the whole assembly in water at about 27 ± 2 °C for 24 hours.
  • Keep the slit closed while filling; paste squeezing into an open slit gives false readings.
STAGE 3

Boiling and measurement

  1. 1Remove the mould, measure the distance between the indicator tips (L1).
  2. 2Place the mould in the water bath and bring to the boil in about 25 to 30 minutes.
  3. 3Keep boiling for 3 hours, then let the water cool.
  4. 4Measure the distance between the indicator tips again (L2); expansion = L2 − L1.
  • Make sure the moulds stay fully submerged during boiling; top up with boiling water if needed.
STAGE 4

After testing

  1. 1Remove the hardened paste carefully without bending the indicators.
  2. 2Clean and dry the moulds and store them flat.
  3. 3Report expansion to the nearest 0.5 mm and compare with the specification (typically ≤ 10 mm for OPC).
In LimsPulse · Calibration Management

Keep every Le Chatelier in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.

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