Study On Rutting Resistance Of Asphalt Pavement Based On Long-Term Performance Data Analysis

Rutting is one of the most common damage forms of asphalt pavement,which seriously affects the driving comfort and driving safety.The depth of rutting is an important control index in the pavement structure design and maintenance.Therefore,the study on the rutting resistance of asphalt pavement has always been a hot topic.A huge amounts of data have been accumulated over years of asphalt pavement construction and maintenance in China and abroad.One of the most outstanding achievement is the establishment of LTPP database.A mass of field data support the deep study of asphalt pavement performance,especially the development of rutting performance,and provide a foundation for comprehensive analysis of rutting factors and pavement structure with well anti-rutting performance.Firstly,the rutting depth distributions of the interest pavement are quite different under the diverise length divisions.Based on the high-density collection of rutting depth data,the distribution of rutting depth is analyzed under different length division,different distance and the combination of adjacent rutting,and the reasonable collection densities is given.Incorporation with the case analysis,the optimum pavement length division based on rutting depth is recommended.Secondly,the traffic axle load is one of the most important parameters for the rutting analysis of asphalt pavement.Because of manual error or mechanical failure,the missing of traffic axle load data records is commonly appeared,time series model is proposed to fill the lack of traffic axle load data.Based on the periodicity of the hourly traffic axle load of each vehicle type,SARIMA and HoltWinters model are utilized to fit and predict the missing data.The prediction results of the two models under the condition of different metadata are compared and analyzed,and reasonable time series models are recommended for different traffic axle load conditions,which provides a method for improving the hourly traffic axle load data.Thirdly,asphalt mixture is a temperature sensitive material.Within different temperature conditions,different rutting depth is accumulated under the traffic axle load.Unfortunately,the coupling effect of temperature and traffic axle load has not been fully considered in the previous rutting prediction model,which is quite different from the actual condition.In the process of study,the temperature is divided into different temperature range with the interval of 10 ?,the equivalent single axle loads(ESALs)in each temperature range are analyzed.Incorporated with different pavement structure forms and fully considering the combined effect of temperature and axle load,the rutting prediction model is established based on the function of ESALs in different temperature range and pavement structure thickness.Fourthly,the thickness of pavement structure is closely related to rutting,and the effect of different maintenance methods is different.Based on a huge number of pavement structure data,maintenance method and rutting depth in different states in LTPP database,combine with the correlation analysis method,the correlation between the material thickness of different layers and rutting depth is analyzed,and the effect of different maintenance methods on rutting is evaluated.Meanwhile,the relationship between the test conditions,material types,thickness and compaction of each layer and rutting is analyzed by the laboratory test of core samples in the field in China.Fifthly,pavement structure combination is an important part of asphalt pavement design,and good asphalt pavement structure combination is an important precondition of ensuring well rutting resistance.The LTPP project provides a large number informations of different pavement structures which set up in each state,combined with the pavement structure data in some districts in China,the comprehensive analysis method is adopted,the cumulative rutting depth,investigation time,ESALs,the days of annual average temperature over 32 ? as the factors,the pavement structure combination with good anti-rutting performance is recommended.