Influence of chloride solution concentration on deicer salt scaling deterioration of concrete

To analyze the influence of the chloride solution concentration on the deic er salt scaling deterioration of concrete, three concrete mires (with seate r-cement ratios of 0.25; 0.35, and 0.45) were prepared and cured in a satur ated lime solution for 180 days. At the end of the curing period all concre te specimens were dried at 20 C and 50 percent relative humidity for 3 week s. For each concrete mix; a first series of specimens was resaturated with chloride solutions at various concentrations in the 0 to 12 percent range. Another series of specimens was resaturated with pure water. After a 3-week resaturation period all concrete specimens were tested in accordance with ASTM C 672. The specimens;resaturated with a chloride solution were tested with the same solution on the surface. The specimens resaturated with water were tested with chloride solutions at different concentrations (always in the 0 to 22 percent range). In addition, the pore-structure characteristic s of each concrete mic were investigated by mercury intrusion porosimetry, and low-temperature calorimetry teas used to measure ice formation after th e drying-resaturation treatment. The test results indicate that low chlorid e concentrations (in the 2 to 4 percent range) always produce more scaling, irrespective of the water-cement ratio. No significant difference was foun d between the specimens resaturated with a chloride solution and those resa turated with water. According to these results, it is the concentration of the outer solution that has the highest influence on the scaling mechanisms .