Freezing and thawing of Building Stone

Freezing and thawing test:

1. Stone specimen is kept immersed in water for 24 hour. 
2. It is then placed in a freezing machine at -12 deg C for 24 hours. 
3. Then it is thawed or warmed at atmospheric temperature. 
4. This should be done in shade to prevent any effect due to wind, sun rays, rain etc. 

This procedure is repeated several times and the behaviour of stone is carefully observed.