Study On Long Term Performance Evaluation And Prediction Of Typical Asphalt Pavement Of Expressway In Hunan Province

With the development of expressways in Hunan Province,the traffic mileage has become larger and the traffic volume has increased rapidly.In particular,the number of overloaded and heavy-loaded vehicles has increased,which has greatly exacerbated the burden of pavement and reduced the performance of pavement..In order to ensure the long-term high service level and capacity of expressways,it is necessary to have overall control of the current and future conditions of typical pavement for taking targeted measures.Therefore,the study on the long term performance of expressways in Hunan Province is particularly important.Based on this,this article carried out the following work and got the relevant conclusions:(1)Combined with the factors,such as the type of expressways asphalt pavement,the combination and thickness of pavement structure,and the type of mixture,which has an important influence on the long term performance of the pavement,the expressways asphalt pavement structure of Hunan Province was divided,and the basic attributes each section and the typical diseases characteristics of the recent(2017)were analyzed.(2)Based on the typical disease characteristics and causes of Hunan expressway asphalt pavement in recent years,a long term performance index system for typical pavements of expressways in Hunan Province was constructed..Based on the historical data of representative road sections of typical pavement structures in Hunan Province,The characteristics of the pavement performance index representing the road sections under normal maintenance and routine maintenance conditions were obtained..(3)Based on the different characteristics of“negative exponential model" and "cosine model",a combination model was built by combining them and the corresponding model parameters were obtained.The parameters indicated that the pavement performance of different pavement structures varies greatly.Generally speaking,the SMA pavement is better than the AC/AK pavement.The mixed foundation is better than the semi-rigid base layer.The CRC pavement base is better than PCC pavement base.The attenuation of RQI index is slower than that of PCI index.(4)The long term performance of expressways asphalt in Hunan Province(within 15 years)was predicted.According to the forecast results,the pavement evaluation rating of each road section was calculated by years,and the differences in the road performance of different sections were obtained,which can provide a reference for the selection of new construction/overhaul of expressways.