What allowance should be made for strengths where air-entrained concrete is to be used?

Q. What allowance should be made for strengths where air-entrained concrete is to be used?

A. For a given required average strength, ACI 211.1 recommends a substantially lower w/cm for air-entrained concrete than for non-air-entrained concrete. These values should be used until experience with the given materials indicates that a change can be safely made. Experience has shown that when the cementitious material content and consistency are maintained constant, the apparent penalty in strength is partially or entirely offset by the reduction in mixing water requirements, which results from the better workability obtained by air entrainment (ACI 212.3R). For concretes with low cementitious material content, air entrainment may actually result in higher strength for a given workability and cementitious material content.

References: SP-1(02); ACI PRC-211.1-22; ACI 212.3R-16

Topics in Concrete: Admixture; Mixture Proportioning