Response of air-entrained concrete to severe chemical aggression

The primary objective of this study is to investigate the response of air-entrained concrete to aggressive chemicals. To better correlate to field practices, 60 concrete mixtures were prepared with three cement contents, five air content ranges, and water content adjusted to yield moderate to high slump ranges. Samples were subjected to abrasion testing and were exposed to sulfuric acid, calcium chloride, and ammonium sulfate solutions. The results reveal that air-entrained mixtures yielded reduced permeability but relatively less abrasion resistance. Yet they demonstrated enhanced resistance to chemicals as expressed by more exposure cycles and/or less mass loss. The combined effect of both exposure duration and mass loss is expressed by a factor (chemical disintegration factor), which is thought to be useful in similar studies. The results suggest that producing high workability, air-entrained concrete with adequate strength and abrasion resistance, low permeability, and superior chemical resistance is possible. This can be useful in sewer structures and concrete applications where surfaces are subjected to mild abrasion and aggressive chemicals.