Is there any way to reduce the air content of a mix which is considerably higher than specified or intended?
Over-entrainment of air can be caused by inadvertently adding double dosages of admixtures or by using more than one admixture, both of which entrain some air. Some aggregates have been known to release air into the mix. The most widely used air-detrainer is tributyl phosphate. Dibutyl phosphate, water-insoluble alcohols, water-insoluble esters of carbonic and boric acids as well as silicones may also do the job. Obviously they must be used judiciously for the concrete to end up with the right amount of air.