A novel high solar reflective coating based on potassium silicate for track slab in high-speed railway

摘要

The aim of this study is to develop a novel high solar reflective coating used for the track slab in highspeed railway to reduce its temperature deformation. In the coating, transparent potassium silicate solution with curing agent and titanium dioxide with high solar reflectance were used as the binder, and the only pigment and filler, respectively. The results showed that the coating possessed a high solar reflectance more than 90%, excellent water resistance to avoid the damage for more than 840 h in water, and an adhesive strength meeting the requirement of the Chinese National Standard. Water content in the coating had a weak impact and a significant influence on solar reflectance and adhesive strength, respectively, while no effect on the water resistance. The results of SEM, XRD, and FTIR showed that the porosity and pore distribution, phase component, and functional groups of the coating were mainly affected by the different ratio of potassium silicate and curing agent, and reaction degree between potassium silicate and curing agent due to various water contents. The high solar reflectance was closely relevant to transparent potassium silicate and the high refractive index ratio of titanium dioxide to potassium silicate when titanium dioxide content being the same in solar reflective coating. The novel high solar reflective coating was potentially used for track slab in high-speed railway to reduce its temperature deformation. (C) 2019 Elsevier Ltd. All rights reserved.