| abstract |
The present invention relates to a method and air entraining admixtures (AEAs) for achieving satisfactory levels of air entrainment in a hydraulic cementitious composition, such as concrete or mortar, in which an oxyalkylene shrinkage reduction admixture (SRA) is used with, or to be used in combination with, a water soluble salt, such as a calcium salt. Addition of exemplary polyoxyalkylene copolymers, preferably nonionic and substantially di-block in structure, and preferably having a molecular weight of at least 1,000 and more preferably at least 2,000, are described for controlling air entrainment. Increased air entrainment effect is further realized when such polymers are used with conventional AEAs, such as tall oils and vinsol resin. |