Study Of Decision Method Of Asphalt Pavement Maintenance Based On National Test

To make maintenance plan reasonably,reduce cost of maintenance,improve performance of pavement,and get expected ranking in the national test,this paper put forward the maintenance decision method based on the national test system.Prediction models for three indicators of roughness,rutting and pavement breakage were established,which was verified by statistical methods in this paper.Through a series of reasonable assumptions,the model for pavement with typical overlay maintenance was established.Based on the national test system,the earliest maintenance timing decision model was established,and a reasonable maintenance scheme was formulated.Through analyzing pavement performance characteristics of Jiangsu Province,we found transverse cracks were the main disease.The change of roughness did not decrease obviously with the increase of time.Due to maintenance bringing recovery of pavement performance,all technical indicators showed a wave attenuation trend.To reduce impacts of key information loss on model prediction accuracy and maintenance decision making,cluster classification method was applied to preprocess prediction data.Considering influence of rutting and cracks,the prediction model of roughness was regarded as the fixed C to simplify the formula of MEPDG pavement roughness model.The simplified formula can reflect the influence of maintenance level on road roughness.The initial roughness after the typical overlay maintenance was 44% of what before maintenance.Based on this,a prediction model of roughness after maintenance was established.In this paper,by changing layers dividing method, of each layer was calculated according to the coefficient matrix of constructed by the existing test data,so as to determine rutting prediction model.When establishing the rutting prediction model after maintenance.,it is necessary to modify the original formula according to the influence of maintainance on modulus and deformation of surface.Assuming that there was initial damage in asphalt pavement,we predicted the distribution of cracks based on cumulative equivalent axis times over the years.After maintenance,the crack distribution function produced a jump point at the depth of crack 140 mm,which reflected the cumulative frequency of the crack 140-180 mm before maintenance.The cumulative frequency of fracture was the area of function and coordinate axis.Longer the age of traffic,higher the frequency of fracture accumulation.Finally,the maintenance decision system under the national test system was established.The expected value and the minimum value were defined to determine the earliest maintenance opportunity under its constraints,and make a scientific maintenance decision plan in five years,and provide the basis for the formulation of a reasonable maintenance plan.