Thermal Performance of Novel Multilayer Cool Coatings for Asphalt Pavements

Abstract

Cool coatings are typically used to address high-temperature problems with asphalt pavements, such as rutting. However, research on the effect of the coating structure on the cooling performance remains a major challenge. In this paper, we used a three-layer cool coating (TLCC) to experimentally investigate the effects of the reflective layer, the emissive layer, and the thermal insulation layer on the cooling effect using a self-developed cooling effect evaluation device (CEED). Based on the test results, we further established temperature fields inside uncoated and coated samples, which were used to study how the TLCC affects the inner temperature field. Our results showed that the reflective layer was the main parameter influencing the cooling effect (8.18 °C), while the other two layers were secondary factors that further improved the cooling effect to 13.25 °C. A comparison of the temperature fields showed that the TLCC could effectively change the internal temperature field compared with the uncoated sample, for example, by reducing the maximum temperature inside, whose corresponding position was also deeper. As the depth increased, the cooling effect of the TLCC first increased and then decreased slowly. The results emphasize the importance of considering the effect of the coating structure on the cooling performance. This study provides a reference for effectively alleviating high-temperature distresses on asphalt pavement, which is conducive to the sustainable development of pavements.

Proposed Cool Coatings with High Near-Infrared Reflectance and Heat Insulation for Asphalt Pavement

“…To ensure the uniformity and stability of the CCL, stirrers and other devices were used. The specific preparation process is shown in Figure 3 [35].…”

Durability of high reflective materials designed for building envelopes

“…As alternatives to mitigate the UHIE, passive technologies have been studied in the past decades, such as the application of materials with high reflectance and high emittance, which is the ability to reflect the biggest fraction of solar radiation, and the ability that describes how fast a material can release the absorbed heat to the environment, respectively. These materials, known as "cool surfaces" (CS), are usually applied as "cool roofs", but have also been developed for several applications, with examples including wall coatings [4], pavements [5], clay tiles [6], cool colourful coatings [7,8], and self-cleaning products [9,10]. According to [11], increasing 0.25 of the roof's albedo between the latitudes 45°N and 45°S could prevent the emission of 90Gt of CO2, which is equivalent to 3 years of the global emission rate.…”

Fractal Analysis of the Fracture Evolution of Freeze-Thaw Damage to Asphalt Concrete

“…Asphalt concrete is the most common pavement construction material for each level of roads; it is characterized by the advantages of energy savings, emissions reductions and superior skid resistance [1,2]. As we know, asphalt is both a thermoplastic and a cementing material, showing sensitivity to temperature changes.…”