Study On Preventive Maintenance Opportunity Of Asphalt Pavement Based On Decay Law Of Pavement Performance

In recent years,with the continuous development of highway maintenance,the preventive maintenance technology of asphalt pavement has been widely applied,and the performance evaluation criteria of asphalt pavement have become mature.For preventive maintenance technology,determining the applicability of each technology and the optimal maintenance time is the key.However,there are still some problems such as preventive maintenance technology,inappropriate timing of preventive maintenance,unclear technical applicability when pavement diseases are serious,which seriously affect the effect of preventive maintenance technology on the repair and improvement of pavement functional status,and can not prolong the service life of pavement.Therefore,in order to meet the needs of highway maintenance,it is of great practical significance to build a decay model based on pavement performance and to determine the optimal maintenance time.Based on the above reasons,starting from the disease situation of Chongqing's general trunk highway,the characteristics of pavement performance change are studied in depth,and the main factors affecting pavement performance are determined to construct decay equation.On this basis,the macro and micro applicable conditions of preventive maintenance technology are analyzed and determined,and the decisionmaking mechanism of preventive maintenance timing is carried out from the perspective of benefit and cost analysis.Research.The main research contents and achievements are summarized as follows:Statistical analysis of preventive maintenance data of general trunk highway in Chongqing shows that the most commonly used preventive maintenance technology is micro-surface and thin-layer overlay.The characteristics of disease changes before and after preventive maintenance of representative sections are analyzed.The main types of disease after preventive maintenance technology are irrigation,repair and various cracks,and the preventive maintenance effect of severely damaged sections is poor.After preventive maintenance technology,the types of overall pavement diseases are basically the same as the main types of pavement diseases in its region.Referring to the current specifications,the partial least squares method is used to pretreat the original road condition detection data.Based on factor analysis method,the contribution degree of influencing factors of pavement performance is analyzed.The main influencing factors are road age and traffic load.The pavement performance prediction methods are compared and the pavement performance decay equation is established.Based on the detection data,eight sections were screened for decay model test.The correlation coefficients were greater than 0.9,and the decay model prediction performance was good.The universal application scope of regression parameters is proposed.Five sections are selected to verify the applicability of the regression parameters.The error values are all controlled below 5%,which proves that the regression parameters have good applicability for Chongqing.The preventive maintenance measures are classified,and the applicable conditions for preventive maintenance measures in Chongqing are put forward from macro and micro aspects by sorting out the local preventive maintenance norms.On this basis,PCI is determined as the key indicator of maintenance timing.According to the lowest acceptable level,a decision-making mechanism for preventive maintenance timing of Chongqing general trunk highway based on benefit-cost analysis method is constructed.An example of Jiangtu Road S428 in Fuling District of Chongqing is taken as an example.