Defoamers

Defoamers are mineral substances that have the function of controlling and limiting the building of foam and micro-bubbles inside concrete and mortar mixtures. 

The benefit of a well formulated defoamer is that it has no affect on the  rheological properties and/or fluid loss characteristics of the cement mixtures. 

Defoamers also have to be compatible with conventional retarders, not affecting setting times, and compressive strength development.