Study On Performance Of Tetradecane-Octanoic Acid Composite Phase Change Asphalt

The efficiency of transportation and the functional requirements of the road surface are important prerequisites for ensuring the rapid development of the economy and society.Roads in cold areas are affected by the low-temperature environment in winter,and roads are prone to icing and cracking.The mixing phase-change materials with asphalt mixture to prepare phase-change asphalt mixture can alleviate low temperature pavement diseases,which is of enormous significance to insure the smooth flow of local traffic and the security of people’s lives and properties.In this paper,the tetradecane and n-octanoic acid composite phase change material are used as the core material,and the PVA modified melamine formaldehyde resin doped with Ti O₂nanoparticles is used as the composite wall material.The in-situ polymerization is used to prepared the Phase change microcapsules T-OAPCMs.Firstly,thermal performance test,infrared spectroscopy test,scanning electron microscope test,and mechanical strength test to study the phase transition enthalpy,microstructure,apparent morphology,and mechanical strength of T-OAPCMs.The finished product T-OAPCMS was added into matrix asphalt and SBS modified asphalt with 4%,7%,10%and 13%,respectively,to prepare phase change asphalt and phase change modified asphalt.Conventional road performance,rheological performance,and temperature control performance of phase change asphalt are tested.The road performance of the phase change asphalt mixture is analyzed and verified.The main conclusions are obtained as follow:1)Compared with monomer phase change materials,the advantages of T-OAPCMs are wide phase transition temperature range,large phase transition enthalpy,good thermal and chemical stability,regular spherical particle structure,and improved mechanical strength;2)It is concluded from the low temperature and low temperature bending test that the low temperature ductility of asphalt binder and low temperature crack resistance of asphalt mixture can be effectively improve by adding T-OAPCMs.3)According to the bending beam rheometer test,T-OAPCMs can reduce the brittleness of asphalt binder and improve its low temperature flexibility,improves the adaptability of asphalt in low temperature environments;4)According to the self-designed temperature adjustment test,T-OAPCMs can make asphalt have a certain temperature adjustment ability and slow down the cooling rate in low temperature environments;5)Based on the analysis of fatigue factor and temperature sensitivity,T-OAPCMs can improve the anti-fatigue performance of asphalt binder and effectively reduce the temperature sensitivity of asphalt,improve the adaptability of asphalt binder under natural temperature change environment;6)From penetration,Softening point and rutting tests show that T-OAPCMs will affect the high temperature performance of bitumen and asphalt mixture;7)From the dynamic shear rheological test,T-OAPCMs will affect the high temperature rheological properties of asphalt,aggravate the heterogeneity of asphalt and increase the stress sensitivity of asphalt;8)According to Brookfield viscosity and water immersion marshall test,T-OAPCMs will affect the adhesion of asphalt itself and the adhesion of asphalt to aggregates.According to the immersion Machel test,T-OAPCM can reduce the water stability of asphalt mixture.