This paper presents the results of study aiming to measure solar spectral properties and the thermal performance of 5 (green, red, yellow, beige and off-white) color thin layer asphalt samples in comparison to a sample of conventional black asphalt. In addition the impact of the application of such materials on pavements (road) on surface and air temperature is evaluated. These materials can be applied on new or existing asphalt pavements that are in good condition. This study consists of three parts a) Spectral analysis and study of the optical properties of the samples b) Study and analysis of the thermal performance of the samples. c) Computational fluid dynamics (CFD) simulation for evaluating the impact of applying the samples in outdoor spaces.

The spectrophotometric measurements showed that the coloured thin layer asphalt samples are characterised by higher values of solar reflectance compared to the conventional asphalt, which is mainly due to their high near infrared solar reflectance. From the statistical analysis of the surface temperatures it was found that all the colored thin layer asphalt samples demonstrate lower surface temperatures compared to conventional asphalt. The maximum temperature difference recorded was for the off-white sample and was equal to 12 οC. The CFD simulation results show that both surface and air temperatures are decreased when applying the colour thin layer sample.