Applicability of solar-reflective coatings on the CRTS III ballastless slab track

The ailment of temperature induced interface damage between the prefabricated slab and filling layer in ballastless track systems continues to persist throughout the tracks’ service lives. Solar-reflective coatings have been proposed as a non-intrusive preventive measure for interfacial damage mitigation in ballastless track systems. In this study, the applicability of solar-reflective coatings on the CRTS III ballastless slab track is investigated, and the varying temperature reduction effects of the coatings on the prefabricated slab vertical deformation and the damage occurrence in the interface are analysed. The findings in this study provide insight on what to expect from the application of solar-reflective coatings on the unit slab-type structure of the CRTS III track. The following conclusions were drawn: (1) The application of a coating with a surface temperature reduction of 10 °C caused a significant decrease in both the upwards warpage and downwards curling of the prefabricated slab by 71.38 % and 25.38 %, respectively. (2) A surface temperature reduction of 10 °C caused an overall decrease in all relevant interlayer stresses in the concrete-SCC interface, with the normal traction, lateral shear and longitudinal shear interface stresses decreasing by 42.5 %, 25 %, and 34.56 %, respectively. (3) The increasing effectiveness of coatings on the surface temperature reduction of the prefabricated slab shows a steady decrease in both the interfacial stresses and interface damage, with no projected risk of diminishing value. (4) Even coatings of moderate effectiveness are enough to significantly decrease both the vertical deformation and subsequent interfacial damage occurrence in the track structure.