Effects of metal–ceramic anticorrosion coating on the performance of ballastless tracks at high temperature

Abstract

A highly reflective metal–ceramic anticorrosion coating is proposed to address temperature-induced track arching and concomitant damage of the China Railway Track System II ballastless tracks. The term ceramic refers to the inorganic phosphate coating binder and the metal pertains to the aluminite powder filler. Its thermal properties were studied through finite element modeling and heat radiation testing of uncoated and coated concrete samples and 1:1 ballastless track slab models. The metal–ceramic anticorrosion coating microstructure and constituent characterization were considered in its cooling efficacy analysis. The insulation temperature of the concrete test pieces increased as the thickness of the primer layer increased. At a primer layer thickness of 100 μm, 200 μm, and 300 μm, the corresponding insulation temperature was 8 °C, 18 °C, and 25 °C, respectively. Moreover, the temperature gradient, longitudinal stress, and vertical displacement of a track slab coated with a 300-μm metal–ceramic anticorrosion coating layer decreased by 29%, 57%, and 51.9%, respectively, which agreed well with the simulation results. The reduction in temperature transfer to the substrate, realized by the metal–ceramic anticorrosion coating, holds great promise for application in the construction industry.