Volume 17, No. 1, 2023
Received: 2022/05/28, Accepted: 2022/09/15
Authors:
An-Xiang SONG; Guo-wen YAO; Rui ZHOU; Xuan-Rui YU; Yue-Rui WANG;
Abstract:
The heat and moisture coupled actions could easily cause deformation, cracking and corrosion diseases to the materials and structure in CRTS Ⅱ slab ballastless track. In this paper, an indoor physical temperature experiment of two 1:4 geometric scale models and their finite element models were carried out to investigate the structural performance of CRTS Ⅱ slab ballastless track subjected to the hydrothermal environment, respectively. It was found that the time-dependent temperature changes of two scale models in the high temperature and high humidity environment are consistent with the environment temperature changes, and there is an obvious temperature-lag effect in the temperature transfer between layers. Then, the positive and negative temperature gradients between the lower part of the track slab and the CA mortar layer of the constraint scale model specimen are smaller than those of the freedom scale model, indicating that the ballastless track under the free boundary is not conducive to the temperature transmission between the track slab and the CA mortar layer. Finally, the longitudinal displacement of the track slab for the freedom scale model is significantly affected under the high temperature and humidity environment, and the longitudinal displacement of the concrete base and the track slab forms a displacement difference, which is easy to form dislocation in the mortar layer, resulting in damage to the mortar layer. In addition, numerical simulation results show that the bottom of the concrete base is prone to produce a high-temperature core, and the temperature inside the track structure forms an agglomeration effect.
Keywords:
CRTS Ⅱ slab ballastless track on bridges; high temperature and humidity test; structural performance; a scale model; finite element model