A novel solar reflective coating with functional gradient multilayer structure for cooling asphalt pavements. (20th June 2019)

• Record Type: Journal Article
• Authors: Jiang, Lei; Wang, Lichen; Wang, Shengyue
• Is Part Of: Construction & building materials. Volume 210(2019)
• Page Start: 13
• Page End: 21
• Publication Date: 2019-06-20
• Subjects: Functional gradient -- Multilayer structure -- Solar reflective coating -- Asphalt pavement -- Cooling pavement; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.03.180
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A novel solar reflective coating was proposed. The proposed coating has functional gradient multilayer structure. The proposed coating could alleviate the high temperature of asphalt pavement. The proposed coating had high cooling efficiency, safety and durability. The proposed coating provides a new direction for pavement coating. Abstract: Solar reflective coating is an effective way to reduce the surface and internal temperature of asphalt pavements. Existing coating is limited by its single-layer structure, and its development has persistent challenges, highlighting a need to study novel coating with high cooling efficiency, safety and durability. In this paper, a solar reflective coating with functional gradient multilayer structure was designed, named FGMC. It consisted of three different functional layers arranged in a gradient from top to bottom, including a near-infrared transmission layer, a strong reflection layer and an insulating bonding layer. The key pigments or fillers used in each layer were determined by utilizing an indoor irradiation test. The optimal dosage of pigment G, pigment Y, titanium dioxide and floating beads was 3.7%, 3.7%, 15.2% and 16%, respectively. The cooling effect of the proposed coating was investigated by comparing the surface and internal temperature of the coated and uncoated asphalt mixture specimens. Results showed that the strong reflection layer contributed the most to cooling effect, reducing temperature about 8.5 °C–9.5 °C. The internal temperature of specimens coated with FGMC used pigment G and pigment Y decreased by 11.5 °C and 13 °C respectively. Moreover, the skid resistance, water resistance, alkali resistance and abrasive resistance of the proposed coating met the requirements of standards. The proposed coating can reduce temperature and provide a new direction for solar reflective coating of asphalt pavements.