Abstract:

Fatigue strength of highway- and railway- bridges under repeated cyclic loads of vehicles is receiving great concerns from engineers and researchers. However few researches are carried out on high fatigue behavior of concrete. Based on the basic principle of the strength theory of rock and the theory of vibration, a method of high vibration testing is applied to non-metallic fatigue damage mechanics such as rock or concrete. In this paper, plain concrete cylinder specimens were tested under high frequency fatigue loads with constant amplitude. The destructive mechanism of concrete is explained by analyzing the rule of frequency variation curve, and a model for nonlinear fatigue damage accumulation under axial compressive loads is established. By taking survival rate and failure probability into account, a fatigue equation is proposed in a double logarithm form. 

Key words: concrete; high frequency experiment; fatigue life; fatigue damage