Study on damage rules on concrete under corrosion of freeze-thaw and saline solution

Abstract

Coastal concrete in cold area is subjected to chemical attacks and freeze-thaw cycles, which both considerably decrease the service life of concrete structures. In this research, we mainly analyzed and assessed the durability of concrete under the coupling action of chlorine ion, sulfate ion and freeze-thaw cycles by designing the orthogonal experiment. In the process of conducting the experiment, the relative dynamic elastic modulus, the mass loss rate, the thickness of damage layer, the velocity of ultrasonic wave and other damage indexes which reflect the damage law of concrete under the coupling action were measured or calculated and the range analysis and variance analysis were used to study the influence degree of different factors. Then the damage evolution equation and the damage constitutive model of concrete were established on the basis of the analysis for damage indexes and the results of mechanical tests. The comparison results showed that the theoretical values well agreed with the experimental ones and the damage model acquired can potentially be used to predict the damage degree of concrete under the coupling effect of chlorine ion, sulfate ion and freeze-thaw cycles.