PEG/SiO2相变颗粒对沥青混合料降温效果研究

Study on Cooling Effect of PEG/SiO2 Phase Change Particles on Asphalt Mixture

为探究复合定形相变颗粒对沥青及沥青混合料路用性能及降温性能的影响,将自制的PEG/SiO2复合定形相变颗粒掺入到基质沥青中制备相变沥青胶浆,通过动态剪切流变仪及模拟升温试验对不同相变材料掺量的沥青胶浆的高温抗车辙性能及温度敏感性进行试验对比研究,最后将其以等体积方式替代FAC-13级配中的0.075,0.15,0.3mm集料,制备出相变储热沥青混合料,并研究0%,3%,5%相变颗粒掺量下沥青混合料比热容、室内外降温效果.研究结果表明,PEG/SiO2颗粒表面的微孔结构能够吸附沥青中的轻质组分,从而间接增大沥青重质组分的相对含量,同时在测试温度范围内因发生固-液相转变而吸收部分热量,因此PEG/SiO2颗粒能够起到储热降温的作用,还可以增强沥青胶浆的高温抗车辙性能;5%相变颗粒掺量下相变沥青混合料最大比热容达到1.35 J/(g·K),室内最高降温幅度可达5℃,室外最高降温幅度为6℃,经长期观测,相变沥青混合料相变循环可靠性高,具有较好的降温效果.

In order to explore the influence of composite shaped phase change particles on the pavement performance and cooling performance of asphalt and asphalt mixture, the self-made PEG/ Si0 2 composite shaped phase change particles are mixed into matrix asphalt to prepare phase change asphalt mortar. The high temperature rutting resistance and temperature sensitivity of the asphalt mortar with different contents of phase change materials are tested and compared by dynamic shear rheometer and simulated heating test. Finally, the phase change heat storage asphalt mixtures are prepared by replacing 0. 075, 0. 15 and 0. 3 mm aggregates in FAC - 13 gradation with the equal volumes of composite shaped phase change particles. The specific heat capacity and the indoor and outdoor cooling effect of the asphalt mixture with 0 %, 3 % and 5 % contents of phase change particles are studied. The result shows that (1 ) The microporous structure on the surface of PEG/Si0 2 particles can absorb light components in asphalt, thus indirectly increasing the relative content of heavy components in asphalt, and absorbing part of heat due to solid-liquid phase transition in the test temperature range. Therefore, PEG/ Si0 2 particles can play the role of heat storage and cooling, and can also enhance the rutting resistance of asphalt mortar at high temperature.(2) The maximum specific heat capacity of the phase change asphalt mixture with 5 % phase change particle content reaches 1. 35J/( g?K), the maximum indoor cooling range can reach 5 X., and the maximum outdoor cooling range is 6 T). The long-term observation shows that the phase change asphalt mixture possesses high reliability of phase change cyclicity and good cooling effect.