Influences of cyclic air temperature and solar radiation on the long-term deterioration behaviour of double-block ballastless track

Double-block ballastless tracks are affected by environmental loading during their service life. The damage evolution of track slab concrete under cyclic air temperature fluctuations and solar radiation is not well understood. In this study, a new numerical simulation framework was introduced to analyze the long-term damage characteristics of ballastless tracks under cyclic environmental loading, considering the thermal properties of the track and the nonlinearity of concrete. The findings indicate that ballastless tracks are prone to cracking under solar radiation. Tensile damage in the track slab concrete increases with prolonged exposure duration. Especially, at corners of concrete sleeper, as the exposure time increased from 1 year to 10 years and 100 years, the tensile damages of concrete increased from 0.384 to 0.479 and 0.565 respectively. To minimize long-term damage in track slab concrete, it is effective to reduce the short-wave absorption rate on the track surface and increase concrete thermal conductivity. Furthermore, it was observed that both thermal effects and long-term tensile damage in a ballastless track increase with longitudinal-continuous length.