Comparative Analysis of Thermally Investigated Pigment-Modified Asphalt Binders

Abstract

Non-black pavement surfaces may be more vulnerable to distress associated with high temperatures due to the high surface temperatures of conventional black asphalt. Since asphalt is viscoelastic and temperature sensitive, it is more likely to be damaged by traffic loading at higher temperatures. This contributes to the urban heat island (UHI) effect, thus necessitating the use of coloring or cooling additives to help lower pavement surface temperatures. In response to these issues, iron oxide red, titanium dioxide white-modified bituminous mixtures, and clear asphalt binder were thermally investigated under different heat fluxes and compared with a conventional binder. In addition, the corresponding asphalt mixtures were prepared and compared with conventional asphalt mixtures. Each combination has also been observed for the rate of heating and cooling. Compared to traditional black bitumen, the clear binder and pigment-modified binder absorb up to 15% less heat. In addition, asphalt made with a clear asphalt binder and pigmented asphalt takes more time to heat and less time to cool than conventional asphalt.