Research on the fatigue performance of self-compacting concrete structure in CRTSIII slab ballastless track under the action of heavy haul train

• Published in: Construction & building materials 2021-10, Vol.303, p.124465, Article 124465
• Main Authors: Zeng, Zhi-ping, Huang, Xu-dong, Yan, Bin, Wang, Wei-dong, Ahmed Shuaibu, Abdulmumin, He, Xian-feng
• Format: Article
• Language: English
• Subjects: CRTS III slab ballastless track; Fatigue performance; Heavy-haul railway; Numerical simulation; Research method; Self-compacting concrete; Train load
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2021.124465

•Full-scale physical model of CRTS III slab ballastless track structure under heavy haul train load.•Force analysis of CRTS III slab ballastless track self-compacting concrete layer structure under fatigue load.•Explanation of fatigue characteristics and damage law of self-compacting concrete layer of CRTS III slab ballastless track.•Research on fatigue life prediction of self-compacting concrete layer of CRTS III slab ballastless track structure under different axle loads. To further explore the fatigue characteristics of the CRTS (China Railway Track System) type III slab ballastless track structure generally used for high-speed railways, the fatigue damage of CRTS III type slab ballastless track structure system under the action of heavy-haul trains was studied. Based on the three-stage model, the CRTS III slab ballastless track structural system fatigue finite element numerical model was established, with particular emphasis on the fatigue characteristics of the self-compacting concrete of the CRTS III slab ballastless track under a load of heavy haul trains. To verify the reliability of the established model, the track structure displacement and stress under static load and fatigue load were analyzed and compared. The results shows that the model can be used to explore the fatigue damage law of the structural system of the CRTS III slab ballastless track under the action of heavy-haul trains. The results of further analysis showed that: (1) For self-compacting concrete, the maximum longitudinal tensile stress is greater than the maximum lateral tensile stress (2) For the longitudinal direction of the lower surface of the self-compacting concrete, once the tensile stress reaches the tensile strength of concrete, the self-compacting concrete cracks; as the number of fatigue loads further increases, more cracks will develop from the sides of the slab centre in the self-compacting concrete (3) The larger the axle load, the higher the stress level of each layer of the track structure, the faster the concrete damage rate, and the earlier the concrete cracks. As axle load is greater than 35 t, the damage of self-compacting concrete is more pronounced.