Comprehensive evaluation of ballastless-track sealants based on macro–micro tests and principal component analysis

Abstract

In order to establish a comprehensive evaluation system of ballastless-track sealants, a method is put forward based on macro–micro tests and principal component analysis(PCA). In this study, the performance parameters of four different ballastless-track sealants (SE, NI, WQ, SY) were obtained by low-temperature performance test, atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) test. Then the PCA method was conducted to reveal the complex relationship between macro and micro performance parameters of sealants, such as the maximum tensile force, the maximum failure displacement, the surface roughness, the surface adhesion, the chemical bonding rate with SiO2, and the principal component contribution rate was calculated. Finally, the comprehensive score was utilized to evaluate the performance of different sealants. The results show that the macroscopic properties of the sealant are closely related to the microscopic parameters roughness, surface adhesion and chemical bonding rate of SiO2. The macro–micro performance parameters of sealant are comprehensively evaluated through PCA, and the results are as follows: NI > SE > WQ > SY. The PCA can comprehensively evaluate the performance of sealant intuitively and accurately, avoiding the subjective influence of evaluating the material performance only through macro-tests or micro-tests.