1.1 This specification covers materials proposed for use as air-entraining admixtures to be added to concrete mixtures in the field. 1.2 The values stated in either SI units or inch-pound units are to be regarded separate This specification covers materials proposed for use as air-entraining admixtures to be added to concrete mixtures in the field. The air-entraining admixture shall conform to the requirements such as initial and final time of setting, compressive stren