沥青路面多层结构涂层的降温性能研究

传统的沥青路面吸热、储热能力强，容易造成沥青路面车辙问题和加剧城市热岛效应的发展，沥青热反射涂层的运用可以有效解决此问题。目前路用热反射涂层的研究大多集中在材料的组成优化上，对涂层结构的研究较少，受单层结构涂层的限制，沥青热反射涂层降温性能发展面临着持续的挑战。针对此问题，本文提出了一种由反射涂层、辐射涂层和隔热涂层组成的三层结构降温涂层，用于沥青路面上可有效降低路面温度。通过室内降温实验研究了多层结构降温涂层中组成材料的最佳掺量和各层涂层的最佳用量，并研究了多层降温涂层的结构组合形式。实验表明，钛白粉、中空玻璃微珠和远红外陶瓷粉的最佳掺量分别为15 %、20 %和15 %；反射涂层、辐射涂层和隔热涂层的最佳用量分别为0.6 kg?m-2、0.3 kg?m-2和0.3 kg?m-2；着色颜料的加入会降低涂层的降温效果；将三种降温填料加入到不同的结构层中，涂层降温性能得到增强，在反射涂层下增添辐射层增加涂层降温达3.70 °C，在反射涂层下增添隔热层可以增加涂层内部降温达1.10 °C，其中，三层结构降温涂层以反射层作为表面层、辐射层作为中间层、隔热层作为底层的组合形式降温效果最佳，表面和内部降温幅度可达10.45 °C和9.22 °C。与单层热反射涂层相比，多层结构降温涂层降温效果更佳，能更有效降低沥青路面温度。

Research on Cooling Performance of Multi-layer Structure Coatings for Asphalt Pavement

The traditional asphalt pavement has strong heat absorption and storage capacity, which is easy to cause rutting and aggravate the development of urban heat island effect. The application of asphalt heat reflective coating can effectively mitigate this problem. At present, most of the research on heat reflective coatings for pavement is focused on the optimization of material composition, and there is less research on the coating structure. Due to the limitation of single-layer structure, the development of cooling performance of asphalt heat reflective coatings is facing continuous challenges. To solve this problem, a three-layer structure cooling coating composed of reflective, radiation and thermal insulation coatings is developed in this paper, which can effectively drop the temperature of asphalt pavement. The optimal amounts of composition materials and each layer of coating in the multi-layer structure cooling coatings were studied by cooling experiments, and the structure form of the multi-layer structure cooling coatings was studied. The results show that the optimal contents of titanium dioxide, mid far infrared ceramic powder and hollow glass beads are 15 %, 20 % and 15 % respectively, and the optimal amounts of reflective, radiative and thermal insulation coatings are 0.6 kg?m-2, 0.3 kg?m-2 and 0.3 kg?m-2 respectively, the cooling effect of the coatings can be reduced with the addition of pigment. The cooling performance of the coating can be improved by designing three kinds of cooling fillers in different structural layers. The cooling ranges of the coating can be increased by 3.70 °C with the addition of radiative layer under the reflective coating, and 1.10 °C with the addition of heat insulation layer under the reflective coating. The three-layer structure coatings combining reflective coating as surface layer, radiative coating as middle layer and insulation coating as bottom layer have the best cooling capability. The cooling ranges of surface and interior in the three-layer structure coatings can reach 10.45 °C and 9.22 °C. Compared with single-layer heat reflective coatings, the multi-layer structure cooling coatings has better cooling capability and can effectively reduce the temperature of asphalt pavement.