Experimental study on the correlation between mechanical properties of concrete and interface strength of coarse aggregate mortar under freezing–thawing.

The frost resistance of concrete is an essential evaluation index in cold areas; however, quantitative analyses of macroscopic mechanical properties and interfacial strength of concrete under freeze–thaw (F–T) action are scarce. Based on rapid F–T cycle tests of concrete, mortar, and interface specimens, with limestone, quartz, and basalt as variables, the internal damage and basic mechanical properties of specimens under F–T action were obtained. Furthermore, the quantitative relationship between the mechanical properties of the specimens, and between the internal damage and the basic mechanical properties of specimens under F–T action was established. The results showed that the properties of a coarse aggregate–mortar interface affected the mechanical properties and frost resistance of concrete specimens to a certain extent. After F–T action, the internal structure of the specimen tended to be loose, and the specimen was in a frozen state. The degree of damage on concrete specimens was more substantial than that on mortar ones. Quantitative analysis also indicated that the F–T erosion of concrete was mainly caused by the damage in the interface transition zone between the coarse aggregate and mortar. [ABSTRACT FROM AUTHOR]