Abstract:The cyclic loading with different frequencies(5,10Hz) and different amplitudes of the bias force(30,35,40kN) was applied to the fatigue test on expanded polystyrene concrete with volume mixing ratio of 30% by MTS 810 for accumulative vibration cyclic number of 20million times. Based on the analysis of variation of the dynamic stress strain hysteresis curves at different cyclic number, corresponding damping ratio and dynamic elastic modulus were calculated. Calculation results of damping ratio and dynamic elastic modulus indicate that expanded polystyrene concrete has superior performance of vibration attenuation, toughness and crack resistance. A slight crack occurs on the expanded polystyrene concrete specimen at about cyclic number of 1570×104, and damping ratio as well as dynamic elastic modulus is relatively stable before and after the small crack occurs. The fatigue life prediction formula of expanded polystyrene concrete is proposed and verified. In addition, the feasibility of applying expanded polystyrene concrete to ballast bed is explored with this prediction formula.