Research On The Degeneration Tendency Of Pavement Performance Of The Asphalt Expressway In Zhejiang Province And The Aiming Maintenance Period

While the high tide of the construction of expressway has faded,expressway companies are now paying heavily attention to the maintenance of expressways.Nowadays,people are encouraged to work as a manager because of the increasing demand of maintenance.However,China has not received a head start in this field and there are only a few theories about maintenance,some of which are mainly about short-time maintenance plans,emergency of maintenance plans and heavily investment on the maintenance plans.In order to solve the above issue of the first two,based on the typical asphalt expressways pavements in Zhejiang Province,this dissertation mainly focused on the systems of maintenance management from evaluation of pavements performance,degeneration of the technologies of pavements,the prediction of dynamic maintenance period and the preference of decisions which are made from maintenance based on the prediction of dynamic maintenance period.The conclusions are :(1)According to normal cases of illness of expressways in Zhejiang Province,the evaluation system and methods were studied.The comprehensive performance of pavements is evaluated by Grey evaluation based on the center point.Then the weights of each single index are determined through experiment-empirical method,which is based on “the function of punishments” and the combination of Bayes formulas and fussy soft set.Analyzing from the comparison of actual cases and the evaluation systems from standards,it can be concluded that it is necessary to decide the comprehensive evaluation method based on Grey evaluation in order to avoid problems that certain points cannot be decided to put in.And as for the huge differences of single factors in some units,it is safe to take experiment-empirical method,which is based on “the function of punishments”.(2)This dissertation also analyzed the influences to the performance of asphalt pavements in Zhejiang Province which is based on the changes of performance and influences.By using the regression of tendency prediction,the degeneration formulas are formed.Compared with BP nerve net and models from Grey system theories,it turned out that under circumstances of few-data,the prediction which is based on Grey system theories is a better one.(3)Setting the timing of maintenance which is on a high degree as the maintenance period's goal,this dissertation cleared the idea of maintenance period after working on the degeneration of performance of pavements and confirmed the standards of predictive maintenance timing.This dissertation mainly focused about maintenance periods and predictive maintenance timing.And the differences of each unit are involved so that the basic model can be modified on the aspect of the factors that influence the performance of pavements.(4)According to the effect of predictive maintenance plan,the degeneration of performance and predictive maintenance timing,the optimized maintenance timing was calculated.During the maintenance period of time,the combination of predictive maintenance plans can be confirmed according to the predictive maintenance timing.And decision-makers can balance the economic analyzing of each plans and select the most suitable one.