Mechanism of High-strength Concrete Damage Evolution Based on CT Observation

Abstract

To study damage evolution of high-strength concrete under the frozen environment, based on the background of YunCheng auxiliary shaft engineering, this paper studies the damage pattern of C100 concrete under loading by applying the method of industry CT scanning. It aims at showing the evolution process of concrete damage by contrasting of the damage factor on standard curing and negative temperature curing condition, which analyzes the trend of damage modulus of elasticity of C100 high-strength concrete uniaxial compression conditioned from the micro level, combining change of fractal dimension of concrete. The results showed that the change of fractal dimension can reflect the evolution trend of inner damage of concrete, fractal dimension is related with the size of concrete when it damaged. Negative temperature frozen brings about the increase of inner hole of high-strength concrete and decrease of modulus of elasticity, and the ratio of damage energy release rate and strain energy release rate decrease, the energy needed by concrete damage is very low. Moreover, the nonlinear positive correlation between fractal dimension and damage factor of high-strength concrete has been gained.