Design Of Drainage High Viscosity Asphalt Mixture And Evaluation Of Its Permeability And Pavement Performance Under Accelerated Loading

Building asphalt pavement with excellent drainage functions is of great significance for the development of sponge cities.The insufficient bond strength between asphalt and aggregate in drainage asphalt pavement can easily cause the asphalt film in the mixture to be eroded and peeled off by water,leading to diseases such as cracking and peeling of the mixture.Therefore,the research and development of high viscosity asphalt is extremely important.Drainage asphalt mixtures have high void content,and the permeability degradation caused by high void content mixtures that are prone to clogging has become a key issue that needs to be addressed.Based on the Shandong Provincial Transportation Science and Technology Plan project "Research on Key Technologies for the Design and Construction of Double Layer Drainage and Noise Reduction Asphalt Pavement in Seasonal Frozen Areas"(2022B110),this paper systematically carried out research on the preparation optimization,performance measurement,and mechanism characterization of high viscosity modified asphalt.Based on accelerated loading tests and on-site tests,this paper conducted research on permeability attenuation and road performance of drainage high viscosity asphalt mixture.Specific research contents include:(1)The effects of the types and amounts of high viscosity modifiers on the conventional properties of asphalt such as softening point,penetration,ductility,dynamic viscosity,and storage stability were investigated.DSR dynamic shear rheological tests and BBR lowtemperature bending beam rheological tests were conducted to evaluate the high and low temperature rheological properties of high viscosity modified asphalt.Using microscopic experiments such as fluorescence microscopy and Fourier transform infrared spectroscopy(FTIR),the microscopic morphology,composition characteristics,and characteristic groups of high viscosity modified asphalt were detected and analyzed,revealing the modification mechanism of high viscosity modifiers on asphalt.The optimal mixture of HVA high viscosity modifier and SBS modified asphalt was determined through analysis,with an optimal content of 8%.(2)The optimal mixture ratio of high viscosity drainage asphalt mixture is proposed,and the best asphalt aggregate ratio of drainage asphalt mixture is determined as 4.6% by leakage test and cantabro test.The road performance of the effluent asphalt mixture was investigated by rut test,low temperature bending beam test,Marshall test,and freeze-thaw crack test.The high and low temperature performance and water stability of drainage asphalt mixture are analyzed.It is concluded that high viscosity asphalt can effectively improve the performance of drainage asphalt mixture.(3)Based on the self-developed small accelerated loading test system ALT-S100,a study was conducted on the blockage and permeability attenuation laws of drainage asphalt mixtures,the influencing factors of void plugging of drainage asphalt mixtures were analyzed,the rutting deformation laws of drainage asphalt mixtures under long-term load under the combined action of high temperature and water immersion were explored,and a rutting depth prediction model was established.Based on X-ray CT scanning and Avizo image processing technology,the microscopic information of voids in drainage asphalt mixtures was characterized,the evolution law of voids under clogged conditions was analyzed,and the microscopic characteristics and permeability mechanism of voids under clogged conditions were revealed.(4)Relying on the construction project of Jinan Huanghe Avenue,a field test section of drainage asphalt pavement was paved.Based on the field test section,a study was conducted on the applicability of drainage asphalt pavement engineering,exploring the blocking and permeability laws of drainage asphalt pavement under real service environments.By embedding optical fiber sensors inside the test section,long-term real-time testing of the mechanical properties of drainage asphalt pavement in a real service environment was conducted.The research in this article can promote cost-effective high viscosity asphalt,promote the application and popularization of drainage asphalt mixtures in urban roads,and have significant significance for the construction of sponge cities and the improvement of road service quality.