Evaluation by CDF test of surface or bulk hydrophobic treatments to increase the freeze thaw resistance of concretes

Deterioration of concrete from freeze-thaw actions may occur when concrete is critically saturated, which is when approximately 91% of its pores are filled with water. Distress to critically saturated concrete from freezing and thawing will commence with the first freeze-thaw cycle and will continue throughout successive winter seasons resulting in repeated loss of concrete surface. To protect from freeze/thaw damage, concrete should be air-entrained by adding a surface active agent to the concrete mixture. This creates a large number of closely spaced, small air bubbles in the hardened concrete. About 4% air by volume is needed with a consequent reduction in compressive strength of about 20%. In this work, the ability of a surface or bulk hydrophobic treatment to improve the concrete resistance to degradation due to freezing and thawing cycles was investigated and compared with a traditional air-entraining admixture. The CDF Test “Capillary suction, De-icing solution and Freeze thaw test” was used to check the resistance to freeze-thaw cycles with or without de-icing salts.