Abstract: In order to study the dynamic properties of large size saturated concrete, we carried out uniaxial compression tests under different strain rates. By using large-scale multi-function static and dynamic triaxial test machine, we prepared cylindrical concrete specimens with diameter 300 mm and length 600 mm and obtained dynamic mechanical properties of the concretes. Then, we analyzed the failure mechanism according to failure shape. Test results show that peak stress and energy absorption capacity increased with the increase of the loading rate, so did peak strain and elastic modulus. On the basis of stress-strain relation, we established a damage constitutive model of concrete. In the model, stress-strain relation conformed with Weibull statistical distribution before peak stress; while after peak stress, the relation conformed with Lognormal statistical distribution. Shear failure at a few conjugated inclined planes were observed . According to crack expansion after specimen failure, we explained the causes of spalling failure of concrete and analyzed the failure mechanism in aspects of material composition and energy absorption ability.

Key words: large size, saturated concrete, dynamic behavior, constitutive model, failure mechanism