Study On Temperature Control Effect Of Sheet High Thermal Conductive Particles/Epoxy Asphalt Phase Change Composite (EAPCCS)

Although the organic phase change material has a temperature regulating effect on the matrix asphalt concrete pavement,the organic phase change material may have a liquid leakage phenomenon during the phase transition,so that the addition of organic phase change material is limited in the asphalt concrete,and as the temperature sensitivity of asphalt,liquid low-temperature phase change materials can not be directly mixed into asphalt,which restricts the temperature regulation ability of asphalt concrete in low temperature environment,and the thermal conductivity of organic phase change materials is low,which greatly weakens the temperature adjustment capability of organic phase change materials for asphalt concrete.In order to solve the above problems,this paper based on the theoretical basis of the research on the temperature regulation performance of matrix asphalt,a sheet-shaped high thermal conductivity particle/epoxy asphalt phase change composite?EAPCCS?has been developed,this material has good thermal conductivity and large heat storage,it can coat a large amount of phase change material well and show strong temperature regulation ability and has good application prospects.Firstly,in order to solve the problem of small thermal conductivity of phase change materials by using laboratory-made sheet-shaped high thermal conductive particles,the best process for rapid synthesis of sheet-like high thermal conductivity particles was studied by microwave molten salt method,the molar ratio of reactants,the ratio of molten salt system,and the microwave heating time were studied on the influence of phase type and microscopic appearance of product during the preparation of h-BN,as well as the aluminum source,the type of molten salt system,the ratio of molten salt system and the microwave heating time were studied on the influence of phase type and microscopic appearance of product during the preparation of?-Al₂O₃.The result showed that the optimal process for the synthesis of h-BN is the molar ratio of boric acid to melamine is 6:1,and the molar ratio of boric acid to NaCl-KCl molten salt system is n_B:n_K+Na=1:6,microwave heating for 60 min and the best process for synthesizing?-Al₂O₃ is Al?NO₃?₃ as the aluminum source and NaCl-KCl as the molten salt system,the molar ratio of the aluminum source to the molten salt system is n _Al:n_K+Na=1:6,microwave heating for 45 min?Secondly,the effects of the addition of low temperature phase change material polyethylene glycol 400?PEG400?and high temperature phase change material 64^#paraffin on the tensile strength,temperature regulation capacity and heat storage for epoxy asphalt were studied respectively.The results shown that the tensile strength of oxygen asphalt decreases with the increase of the amount of phase change material,and according to the engineering requirements for the tensile strength of epoxy asphalt,the maximum addition amount of PEG400 in epoxy asphalt during 10¹5%,and the maximum addition amount of64^#paraffin in epoxy asphalt is more than 25%.With the increase of phase change material,the temperature adjustment ability of epoxy asphalt is gradually strengthened,for PEG400/epoxy asphalt phase change composite,as the amount of PEG400 increases,the temperature drop rate of the sample in the low temperature environment becomes slower,and for the paraffin/epoxy asphalt phase change composite,the heating rate of the sample is slower with the amount of paraffin addition increases in the high temperature environment.The heat storage of the epoxy asphalt phase change composite?EAPCCS?increases with the addition of phase change material.At the same time,the study also showed that epoxy asphalt has good coating properties for both PEG400 and 64^#paraffin.Finally,The effects of the addition of sheet-like high thermal conductivity particles h-BN and?-Al₂O₃ synthesized by the best synthesis process on the tensile strength,temperature regulation and thermal conductivity for EAPCCS were investigated.The results showed that the tensile properties of EAPCCS shows well after added flake-shaped high thermal conductive particles.The addition of flake-shaped high thermal conductivity particles in EAPCCS will increase the thermal conductivity of EAPCCS,so that results the cooling rate of PEG400/epoxy asphalt composite in low temperature environment is increased,and the heating rate and temperature range of 64^#paraffin/epoxy asphalt composite in high temperature environment is reduced Compared with?-Al₂O₃,h-BN crystal has regular growth shape and excellent thermal conductivity,and its temperature regulation effect on EAPCCS is more significant.