Scaling, as far as this article is concerned, is the disintegration of a concrete surface due to the action of de-icing salts. The deterioration often is progressive and, if unchecked, eventually requires resurfacing or replacement of the slab. It is, of course, most common on horizontal slabwork such as pavements, driveways, and sidewalks where salts are applied. However, scaling sometimes occurs on vertical surfaces adjacent to slabwork when traffic splashes the salt solution. There are a number of factors that influence the scaling resistance of concrete, among them air content, curing, concrete age, strength, aggregate soundness, placing and finishing techniques, type of de-icer used, and protective treatments. A failure in any one of these areas can result in serious scaling. Vibration is, of course, a valuable adjunct to good concrete construction since it reduces void formation and makes it possible for the contractor to use a lower slump concrete. However, its use should be controlled to minimize undue reduction of air content. Prolonged vibration will substantially lower the air content of a concrete mix and this in itself would sometime be sufficient to lower the weatherability of concrete enough to result in scaling. Most authorities believe that moist curing provides better scale resistance than theat offered by membrane curing compounds- if a period of air drying is provided before the concrete is exposed to freeze-thaw cycles and /or de-icers. Curing is important because good curing will help concrete develop the proper strength- a necessary prerequisite for producing scale-resistant concrete. Lack of curing can result in strength reduction up to one-half that of a comparable, well-cured mix. Transporting and placing procedures that encourage segregation also increase the likelihood of scaling, especially with high-slump mixes. As water and fines rise to the surface, lightweight materials- such as any organic material contained in the aggregates- do the same. This results in concrete with a low air cement, a high concentration of deleterious materials, and a low strength at the surface, precisely where they are most undesirable for maximum scale resistance.