Performance Evaluation And Change Regularities Of Asphalt Pavement Of Expressway Network

The paper is based on the practical project of "Long-term maintenance planning and support technology of expressway asphalt pavement in Zhejiang Province”. In view of the practical need of the project, by adopting the pavement performance detection data and maintenance data of Zhejiang Province expressway network as object, the main work has been done is as follows:Frist of all, based on the pavement performance detection data of year 2014 and 2015, the performance condition and its changes of asphalt pavement of Zhejiang Province Expressway Network is analyzed. The typical distress and its composition of the expressway network is also explained by taking some typical routes of the network as examples.Secondly, combined with the existing maintenance evaluation and decision-making index system, the disadvantages of using the index of PCI to determine different maintenance classification are analyzed. The influence of using 1km as the evaluation unit-length in expressway network maintenance demand analysis is shown by an example. The difference in performance evaluation results of pavement performance of the same direction in different lane is also analyzed, which illustrates the necessity of lane division in actual maintenance demand analysis and performance prediction.Thirdly, based on the disadvantages of existing maintenance evaluation and decisionmaking index system, the distress rate DRB and the maintenance rate of distress Xη are put forward, which is used to make up for the deficiency of the existing maintenance decision index. Then the use of the indexes is also explained. Based on the distribution of the evaluation indexes, the regularity of the evaluation results when the evaluation unit length changes is analyzed. It shows that in the existing maintenance level of Zhejiang Province, it is necessary to take smaller evaluation unit-length when analyzing the maintenance demand of the network. Then, based on pavement maintenance data of expressway network, the classification of asphalt pavement maintenance is analyzed, and by comparing with the classification of asphalt pavement maintenance in current specification, further optimization of classification in this province is made. Combined with the research results and discussions with local engineers, the typical maintenance plans of each maintenance technique and the application of each plan are analyzed. Then, the importance degree of each evaluation index is analyzed, and the maintenance standards of the indexes for distinguishing various types of maintenance are given.Last but not the least, based on Markov probability prediction method, the paper constructs the network level performance prediction model and analyzes the use of the index changes of future years combined with overall maintenance management decisionmaking needs. In consideration of the effects of different unit-length to the distribution state of different pavement performance index, the paper uses statistical methods to derive the transfer probability matrix by taking length of 100 m and 1km as evaluation unit. Based on the requirement of maintenance planning, the construction method of the deterministic prediction model is analyzed, and the method of using the model is illustrated with an example.