Experimental study on the interface fatigue between track slab and self-compacting concrete for CRTS III slab track

Abstract

With the rapid development of high-speed railways, the CRTS III slab track has become one of the most important track structures. The interface between the precast track slab and cast-in-place self-compacting concrete is easily damaged under fatigue loads. However, experimental research in this field is still relatively lacking. By performing static and fatigue splitting tensile tests, the study first obtained interface failure characteristics between the track slab and self-compacting concrete. Most of the interface failures were mortar failures and mortar-aggregate bond failures, and only a few were aggregate failures. Then, the evolution law of interface strain was analyzed. The interface strain was large in the middle and small on both sides. The change of interface strain with fatigue life ratio was divided into three stages: rapid growth, stable growth, and unstable growth stages. Moreover, the S-N curve of the interface was obtained. Finally, based on the residual strain, an interface fatigue damage model was established to reveal the evolution law of damage variables with fatigue life ratio under different stress levels. This study makes up for the insufficiency of current interface damage research on CRTS III slab track and provides the reference for the subsequent numerical simulation and engineering application.