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Definitions & History

What is false set of cement paste?

The term "False set" is used to describe the premature stiffening of the cement paste (without much heat generation) which at times occurs within 10-15 minutes of mixing with water.

This is caused by dehydration of Gypsum due to high temperature during the cement grinding process. However, the plasticity of the paste is regained on remixing.

False set - Rapid rigidity without much heat generation, plasticity can be regained (until it sets in the normal manner) without a loss of strength by further mixing with no additional water. Reuse is thus possible.

It differs from Flash set in that no appreciable heat is evolved, and remixing the cement paste without addition of water restores plasticity of the paste.

FAQs

What are the causes of False set?

How do we find out if a cement is having False set & what do we do then?