False Set

Summary

False Set - A false set is a stiffening of fresh concrete after mixing or placement. The original plasticity of the concrete can be restored by mixing.

Technical Information

A false set, different to flash set, can be caused by excessive formation or gypsum crystals shortly after placement, which leads to rapid stiffening.

However the concrete may be re-tempered and re-mixed to restore its original plasticity.

The re-tempering or re-mixing of a false set concrete may be done without any long term damage to the concrete as long as the maximum allowable water / cement ratio and slump are not exceeded.

Special care needs to be taken whilst re-tempering.