Evaluation index and improvement method for interlayer bonding property of ballastless track

Inadequate bonding can bring detrimental interlayer separation problems in high-speed slab ballastless tracks. Thus, it is imperative to elucidate the stress characteristics of the interlayer in high-speed railway ballastless track when subjected to the combined influence of train and environmental factors. The present study employs finite elements to elucidate the change pattern, with the CRTS III slab ballastless track serving as an illustrative case. The findings indicated that interlayer separation of ballastless track under coupling effect of temperature gradient and train load was primarily attributed to shear stress. An evaluation index of "shear bond strength >= 2.50 MPa" was proposed and used to assess interlayer bonding performance of ballastless track in highspeed railway. Additionally, based on polymer modification technology, a method of using phenylpropylene and styrene-butadiene emulsions has been developed to improve the interlayer bonding behaviour of high-speed railway ballastless track. This work is expected to provide theoretical and technical support for a prolonged service life of high-speed railway ballastless track.