Experimental study on high-cycle flexural fatigue behavior of cement mortar for ballastless track of high-speed railway

Abstract

Cement mortar (CM), an important component of concrete, is the phase where fractures and failures predominately appear. The present paper conducted static and fatigue tests regarding four maximum stress levels (0.65, 0.70, 0.75, and 0.80) on CM specimens, aiming at determining the flexural fatigue properties of CM for ballastless track concrete. The S-N curve were fitted, and the fatigue damage model were established. Results demonstrate that the fatigue strain evolution curves showed a three-stage inverted S-shaped law. The CM specimens’ fatigue modulus degradation values ranged between 3.2 and 4.5 GPa. The fatigue damage evolution curves rose as stress levels increased, indicating that higher fatigue loads would lead to larger damage in earlier stages and smaller damage in later stages.