Research On Post Evaluation Of Preventive Maintenance Technology For Asphalt Pavement Of Expressway In Jiangxi Province

From the development trend of highway construction and maintenance in recent years,the focus of highway work in Jiangxi Province is transitioning from construction-oriented to construction and maintenance,and will soon change to a maintenance-oriented development mode.Scientific and reasonable post-preventive maintenance assessment of asphalt pavement can maintain good performance of the pavement,which is of great practical significance to reduce maintenance costs and achieve energy conservation and emission reduction.In this thesis,after researching and analyzing the preventive maintenance technology adopted by several highways in Jiangxi Province,we establish a preventive maintenance performance decay model to realize the post-assessment of the usage performance,economic benefits and environmental impact of preventive maintenance technology.The comprehensive post-evaluation of preventive maintenance technology is further carried out to provide a technical basis for scientific and reasonable guidance on the selection of preventive maintenance technology.Firstly,we analyze the natural climate characteristics of the province and the structural characteristics of the highway pavement,investigate and collect the maintenance history data of six kinds of pavement preventive maintenance technologies(in-situ thermal regeneration,adhesion wear layer,micro surface treatment,UTM ultra-thin overlay,easy compact thin layer overlay and normal temperature ultra-thin overlay)applied on the highway in Jiangxi Province,and sort out the traffic volume and pavement performance testing data of the relevant road sections.Secondly,PCI,RQI,RDI and SRI are selected as pavement damage evaluation indexes from the pavement service performance evaluation system,and a gray system GM(1,1)model is used to predict the asphalt pavement service performance by combining the characteristics of the road condition data,and based on the prediction results,the performance decay of different preventive maintenance techniques after implementation of asphalt pavement in Jiangxi province is analyzed,and the applicability of different preventive maintenance techniques in the province is evaluated.In this province,the application status of different preventive maintenance techniques is evaluated to provide reference for the pavement maintenance department when carrying out preventive maintenance work.Again,from the GM(1,1)model of preventive maintenance techniques,the corresponding pavement performance prediction standard model was established,evaluation indexes were selected,and the comprehensive cost-benefit ratios of different preventive maintenance techniques after 3,5 and 7 years of construction were calculated considering the traffic volume and maintenance costs of different sections of highways in Jiangxi Province,so as to evaluate the respective economic benefits,and the results showed that: after 3 years of implementation of preventive maintenance techniques,the use of The results show that: after 3 years of implementation of preventive maintenance technology,the use of micro-surface has good economic benefits and is cost-effective;after 5 years of implementation of preventive maintenance technology,the benefit index of easy compact thin layer cover is the best;after 7 years of implementation of preventive maintenance technology,the use of easy compact thin layer cover,plus adhesive wear layer and normal temperature ultra-thin cover can make the maintenance funds produce the maximum benefit.Subsequently,based on the quotas,the energy consumption and carbon emission generated by different preventive maintenance technologies at different stages of application were quantified and the environmental impacts of various preventive maintenance technologies were evaluated,and the results showed that: the in-situ thermal regeneration technology is environmentally friendly,with energy consumption and carbon emission accounting for 25.56% and 27.62% of the UTM ultra-thin cover;the energy consumption at 1 m3 of tacky abrasive layer and micro-surface is lower than2000 MJ;the three cover types Preventive maintenance techniques produce energy consumption and carbon emission in the mixing stage of the mix accounting for30%～50% of the whole production process.Finally,using hierarchical analysis,the technical condition,economic benefits and environmental impacts of the pavement after the implementation of maintenance technologies were selected as the primary indicators,and six secondary indicators of PCI,SRI,cost,service life,energy consumption and carbon emission were further selected to evaluate the comprehensive effects of different preventive maintenance technologies after their application in Jiangxi Province.