Study On The Heat Storage And Road Performance Of Phase-change Asphalt Mixture

Asphalt pavement is widely used and also faces a series of temperature diseases which will affect pavement performance,such as rutting,translation,folding and bleeding,etc.Under the condition of high temperatures,asphalt pavement will release volatile organic compounds which can pollute the environment and exudes much heat to increase the atmospheric temperature time and intensify the heat island effect.Basing on the features of phase change materials(PCM),articles developed a Composite amorphous phase change material suitable for asphalt pavement in order to adjust pavement temperature.Firstly,according to the requirements of the asphalt pavement,polyethylene glycol(PEG)is choosen as the target phase change material because of its approciate phase transition temperature,high enthalpy,stable crystallization performance,stable chemical structure amd high thermal stability.PEG/SiO2 composite phase change materials are prepared by the temperature procoagulant,and DSC,TG,FTIR,XRD and other characterization techniques are uesed the study its thermal performance,the distribution of PEG in SiO2 internal skeletal structure,the surface of the crystal morphology,the role of mechanism of the phase transition behavior.Drying and grinding the obtained composite phase change materials,PCM particles less than 0.6mm are used in asphalt mixes.Through indoor contrast test,PCM particls are added to the mix by replacing an equal volume of fine aggregate to prepare suspended dense structure of asphalt(AC-13)and dense asphalt skeleton structure mix(FAC 13,FAC16),and the effects phase transition particle content and gradation have on phase-change thermal properties of asphalt,cooling effect and some road performance are also researched.The results show that the phase change asphalt mixtures have better cooling effect which is related to the pavement temperature.At the same pavement temperature,the cooling rate is proportional to the dosage of the phase transition particles,the higher the dosage,cooling effect is more significant.Under the conditon of 5%PCM particles content and pavement temperature 60?,its cooling rate can reach more than 5?.Gradation has little effect on cooling effect,and the dynamic stability of AC-13 decreases rapidly with the incorporation of PCM particles.However,the high temperature performance of FAC can still meet regulatory requirements when the content of PCM particles is up to 5%.The incorporation of PCM particles has a little effect on the low temperature crack resistance of asphalt mixture.In addition,the performace of water stability decreased after the incorporation of PCM particles because of its hydrophilic effect,but still be able to meet the specifications of the required value.