Effects of Air-Entraining Admixtures on Stability of Air Bubbles in Concrete

Abstract

Effects of synthetic and neutralized vinsol resin (NVR) air-entraining admixtures (AEAs) were compared through air-content measurements of freshly mixed concrete, hardened cylinders, and cores from field and laboratory concrete, and through a modified foam drainage test. The results show that air bubbles entrained with synthetic AEAs are less likely to survive during concrete sampling procedures than those entrained with NVR-based AEAs, leading to larger discrepancies between air-content measurements using the pressure method and the air content established from pavement cores. These discrepancies in turn can prompt imposition of contractor penalties, delays in construction, and controversy with potential longer-term impacts on concrete pavement longevity.