Research On Preventive Maintenance Technology Of Synchronous Thin Overlay In The First Loop Expressway Of Foshan City

With the gradual decay of the asphalt pavement performance indicators, in order to maintain its excellent service performance, at the right time and choosing the right maintenance way to repair is getting more and more attention, so the preventive maintenance techniques of asphalt pavement has become one of the hot spots in the road engineering field. This thesis is basised on the project of preventive maintenance of aspahlt pavement in the First Loop Expressway of Fo-shan City to carry out the research on preventive maintenance of synchronization thin overlay.(1) The disease survey of the old pavement of the First Loop Expressway of Fo-shan City shows that the pavement condition overall is good and suitable for preventive maintenance. Accordingly, through the comparison of application effects, construction technology and economy for common maintenance measures at home and abroad, it shows that the synchronous thin overlay is more suitable than the other part of the preventive maintenance in the First Loop Expressway of Fo-shan City. Therefore, the mixture gradation and design scheme of synchronization thin overlay were proposed on the basis of referencing the NovaChip.(2) The high viscosity modified asphalt, polymer modified asphalt emulsion and all grades of aggregate shall comply with the design requirements by raw materials performance test, and the raw materials can be applied to synchronization thin overlay. At the same time, through the Marshall design method and pavement performance tests, the target mix, production mix and optimum asphalt aggregate ratio of asphalt mixture were determined for the synchronization thin overlay, and can be used to guide the construction of test section.(3) According to the actual situation of the disease types and severity of the old asphalt pavement, the targeted treatment procedures and processes were proposed. Through the construction of the test section, the construction technology of synchronization thin overlay were determined such as mixing, transportation, paving, compaction, joint treatment and opening of transportation etc. for asphalt mixture. Meanwhile, according to the construction situation of test section, the construction precautions, acceptance standards and appearance evaluation standards were proposed.(4) Through the testing of application effects of the test section, all are met design requirements such as the spraying volume of polymer modified emulsified asphalt, pavement texture depth, friction coefficient, permeability coefficient, paving thickness and degree of compaction for the synchronization thin overlay. It indicated that the construction process of synchronization thin overlay was properly, the pavement skid resistance and drainage performance were excellent.(5) Through the comparison of common asphalt mixtures of synchronization thin overlay at home in economy, technology and performances, it shows that the synchronization thin overlay compared with SMA-13 and AC-13 has simple construction process, little influence on traffic, low cost, superior performances and better social benefit to be more suitable for preventive maintenance projects.In short, the application of synchronous thin overlay in high-class highway preventive maintenance can be carried out effectively to extend the life of the pavement, and have a greater economic and social benefits. Therefore, the research results in this thesis can provide a reference for other similar engineering.