Nondestructive monitoring for development of internal structure of concrete at subzero temperature

In order to realize the nondestructive monitoring for the development of internal structure of concrete in winter construction, the variation of dynamic elastic modulus of concretes with ages was investigated, which were cured under standard conditions, at constant negative temperature and at outdoor varying negative temperature. The results show that the high dosage of anti-freezing salts results in certain internal structure damage of concrete under standard curing conditions. In the negative temperature stage, the extraordinarily high value of dynamic elastic modulus of concrete is attributed to ice content in concrete. After moving the concrete cured at subzero temperature into a standard curing room for a certain period, the attenuation of dynamic elastic modulus can be applied to the determination of damage degree of concrete during subzero temperature curing stage, and the development rule of dynamic elastic modulus of concrete accords with that of compressive strength of concrete. Therefore, this non-destructive testing method can be applied to concrete construction in winter.