Abstract
Polyurethane solidified ballasted track (PSBT) offers a novel solution to the frequent maintenance requirements of ballasted track, delivering a high-quality track infrastructure. In this study, laboratory tests were carried out on polyurethane solidified ballast (PSB) specimens under compression, tensile and shear conditions to obtain stress-strain curves and deformation characteristics. The numerical model of the PSB specimens was developed based on the discrete element method (DEM). The effects of the parameters related to the bond elongation on the tensile and compressive properties of the PSB specimens were analysed, and the parameters were calibrated by the test results. The results showed that the compressive, tensile and shear strengths of the specimens increased with increasing polyurethane foam density. During uniaxial and split loading, the stress-strain curves of the PSB specimens gradually entered the stress softening stage after an elastic phase. The compressive-tensile strength ratio of the specimens was around 1.55. From the perspective of deformation, the PSB specimen is primarily strained by the highly compressible polyurethane materials, and the specimen generates a considerable residual strain at the initial stage of cyclic loading. Thus, it is necessary to pre-compress the PSB to achieve an optimal load-bearing condition. DEM simulations show that there is a strong correlation between the mesoscale bond elongation of particles and the macroscopic tensile and compressive strengths of the specimens. It is therefore possible to utilise a high value of bond elongation to simulate bonded granular materials with low compressive-tensile strength ratios. The results obtained from the simulation of the numerical method used in this study are in high agreement with the test, which provides a new idea for revealing the meso- and macro- mechanical properties of PSB and its application in PSBT.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
