Study On Durability Performance Of Permeable Asphalt Mixture In Seasonal Frozen Zone

Because of its large gap,the permeable asphalt mixture has the advantages of discharging water from the road,reducing noise,and reducing the occurrence of traffic accidents caused by water fog on the road.The temprature thermal in the northern seasonal frozen zone is relatively large,the winter is cold and long,and the summer is hot and hot,which makes the durability of the permeable pavements face greater tests.The anti-aging effect of high viscosity modified asphalt can effectively solve these problems.However,the research on thermal aging prediction and evaluation of anti-aging properties of high viscosity asphaltenes is insufficient.In this paper,the three indexes of high-viscosity asphalt with different high-viscosity modifiers dosage were studied,and the modifier dosage with excellent anti-aging performance was determined.Firstly,Liao He 90# asphalt and domestic OLB-1 high-viscosity modifier were used to prepare high-viscosity modified asphalt.The aging test of high-viscosity modified asphalt was carried out in rotating thin-film oven to test the softening point,penetration and 5℃ ductility of different high-viscosity modifiers.The research results show that the nonlinear high-viscosity asphalt aging equation can be established by the test results,which can accurately predict the performance index of high-viscosity asphalt after aging at any time and arbitrary dosage.The weight of the index is determined by the analytic hierarchy process,and the grey correlation degree is used as the criterion to select the modifier dosage with excellent anti-aging performance.The research conclusion breaks through the aging study of high-viscosity asphalt under the coupling of time and dosage,which is helpful for the evaluation and prediction of asphalt anti-aging performance.Design grading based on physical engineering,and by adjusting the oil-stone ratio to produce permeable asphalt mixture with the void ratio of 19%,21% and 24% respectively,the change of road performance after freeze-thaw and aging was studied to determine optimum porosity of the permeable pavement of the northern seasonal frozen zone is determined.Based on the climatic characteristics of the seasonal frozen zone in north China,a freeze-thaw split test was carried out to simulate the frost heaving effect of the permeable asphalt mixture in the gap of rain and snow during freezing,and to sudy the spalling and loosening and other water stability caused by it.Through the three sets of specimens with void ratios of 19%,21%,and 24%,the comparative analysis of the freeze-thaw split ratio was carried out,and the durability of permeable asphalt mixture with the void ratio of 19～21%was determined to be the best.The SEM image was analyzed by Image J software to extract spalling area of asphalt film.The results show that the percentage of spalling area of the void ratio is 19% and21% asphalt film is about the same,which confirms the macro performance.In view of the problems existing in the process of mixing,transportation and paving ofpermeable asphalt mixture,aging occurs to varying degrees,resulting in loose spalling of pavement.In order to study the anti-aging performance of permeable asphalt mixture,the oven heating method was used to simulate the actual engineering environment,and pavement performance and microscopic electron microscope of permeable asphalt mixture were analyzed.The research results show that the comparative analysis of the road performance of the specimens with the void ratios of 19%,21%,and 24% after different aging time has determined that the void ratio with the best anti-aging performance is 19%.Combining the advantages of grey prediction and Markov model,the grey-Markov model is established to predict the decay law of the pavement performance of permeable asphalt mixture with recommended void ratio.The test results show that the accuracy of the gray-Markov model can be improved by 62.88% based on the grey prediction model,which is more suitable for the long-term prediction of the durability of the permeable asphalt mixture.The results provide a new method for the analysis of road performance evaluation of permeable asphalt mixture in seasonal frozen zone.