proportions instead of using admixtures (except air-entrained ones). When possible, examine all alternatives
before using an admixture to determine which is more economical and convenient
Air-Entrained Concrete
A major advance in concrete technology in recent years is the introduction of tiny disconnected air bubbles into
concrete called air-entrainment. Air-entrainment concrete results from using either an air-entrained cement or an
air-entrained admixture during mixing. Adding entrained air to concrete is recommended for most purposes
because it provides important benefits in both plastic and hardened concrete, such as resistance to freezing and
thawing in a saturated environment. Air entrapped in non-air-entrained concrete fills relatively large voids that
are not uniformly distributed throughout the mix. However, entrained air is well-distributed throughout the mass
as shown in Figure 1-7. Note that the microphotograph is scaled in hundredths, not thousandths of an inch,
although the bubble diameters actually have sizes of less than 0.004 of an inch. Air-entrained concrete improves
its workability, watertightness, and resistance to deicers and sulfates.
EN5466
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