Damage assessment of the CRTS III ballastless slab track in high temperature regions

Temperature-induced interfacial damage between the prefabricated slab and filling layers is a common ailment faced by slab-type ballastless tracks systems. In this study, the damage behaviour of the CRTS III ballastless track in high temperature regions is explored. To this end, a 3-dimensional finite element model of the CRTS III ballastless track is built in Abaqus, which takes into account the non-linear temperature distribution along the track depth, the non-linear cohesive relationship between the concrete to self-compacting concrete interface, and the constitutive stress-strain relation of concrete. Upon subjecting the model to various temperature and wheel loading conditions, the following main conclusions were drawn: (1) Upward warpage of the prefabricated slab undergoes an average percentage increase of 37.62 % with each 10 degrees C/m increase in temperature gradient, signalling a greater up-warping effect in higher temperature regions; (2) the stresses along the interface's first and second shear directions have the greatest influence on damage initiation of the interface; (3) under the effect of equally increasing temperature gradient loads, interface nodes where damage initiation had taken place showed a steady increase with an average difference of 5.21 %; (4) applied wheel loads significantly increase the damage initiation area of the track, but the effect of varying concentrated forces typically experienced during the track's service life does not affect the change in damage initiation area as severely.