Evaluation of effective parameters on pavement surface temperature

The elevated temperatures adversely affect the durability and lifespan of pavement. Understanding the factors that influence asphalt pavement temperature offers valuable insights for creating climate-friendly cities with cooler pavement surfaces. In this study, three aggregates of varying types and colors, two types of bitumen (one without pigment and one with the addition of red pigment, Fe₂O₃), and two levels of mean texture depth (MTD), high and low, were utilized to create asphalt samples using Marshall's method. A total of 38 thermocouple sensors were employed to simultaneously record temperatures in three areas within the samples, as well as the temperatures in shaded and sunlit conditions over a period of 17 days. Furthermore, a comprehensive evaluation was conducted to assess the impact of each factor on the solar reflectance index (SRI). Twelve general linear models (GLMs) were developed using a full factorial design of experiment, and five models with an R² greater than 95% were evaluated and analyzed. The analysis, based on the coefficients derived from the GLMs, indicates that the mean MTD is the most significant parameter affecting surface temperature. Pigment color emerged as the second most influential factor affecting both surface and bottom temperatures. Additionally, the findings revealed that MTD has the greatest impact on the SRI, followed by pigment color and aggregate color. It was also determined that the interaction between density, pigment color, and aggregate color plays a crucial role in determining the temperatures of both the surface and bottom of the specimens.