Freezing-thawing resistance evaluations of concrete pavements with deicing salts based on various surfaces and air void parameters

Abstract

The interaction of deicing chemicals and freezing-thawing cycles produces serious scaling damage of airport concrete pavement. The indoor test of freezing-thawing resistance with deicing salts of concrete is still open to the question, and the indirect evaluation method has inherent disadvantages. In this study, the damage process of different surfaces of concrete when immersed into deicing salt solution was compared and analyzed. Roughness growth ratio (RGR) was proposed to quantify the degree of pockmark caused by salt freeze damage. Industrial computer tomography (CT) technology was used to scan the hardened cement concrete specimens to obtain the bubble structure distribution information. The void-to-void distance as a factor was proposed to evaluate the freezing-thawing resistance with deicing salts performance of the cement concrete, and compared with the Power’s spacing factor of the salt resistance performance of the hardened cement concrete in the existing specification. The results revealed that the molded surface showed the worst resistance to the salt frost action, followed by the molded side, and the sawed side was the best. It was found that there was a good correspondence between the air content of concrete test surface and the mass loss during freezing-thawing cycles. Powers’ spacing factor was found to underestimate the resistance potential to frost damage when compared to the void-to-void distance factor d-, which had a good correlation with scaling mass at 28 freezing-thawing cycles. Thus, the freezing-thawing resistance with deicing salts of the cement concrete could lead to introduce the void-to-void distance factor d- for characterization of hardened concrete.