Thermal Behavior of Insulated Slab Tracks in Cold Regions: An Experimental and Numerical Study

Abstract Because of the complex temperature conditions in cold regions, the slab track is prone to defects such as interlayer debonding, voiding, and other diseases, significantly affecting high-speed railway operations. An efficient method of providing thermal insulation on a slab track is to apply insulating materials to the concrete's surface. In this study, the distribution characteristics of the temperature field of the slab track under various thermal insulation measures were comparatively analyzed by using long-term monitoring full-scale experiments, and the thermal insulation effect of the selected measures in different seasons was quantified. The findings include: (1) Insulation measures reduce heat transfer between the environment and the track, enhancing thermal insulation. (2) As the measured extreme value of the negative temperature gradient of the track slab −46.91°C/m exceeds the specified minimum design value (−45°C/m), it is recommended to customize the design values of negative temperature gradients based on local conditions in various cold regions. (3) The thermal insulation measure reduces the maximum temperature gradient of track slabs by 44°C/m in summer and 18°C/m in winter compared with no insulation, impacting the duration of positive and negative temperature gradient effects. (4) The temperature field distribution on both sides of the track structure differs due to varying solar radiation.