Technical Study On Damage Deal In Asphalt Pavement Base In DeZhou South External Loop

With the rapid development of highways, the overall technological level of road network in china has been greatly improved and the transport structure also has been optimized. Correspondingly, it strong advances economic development and social progress. Because of Lime fly-ash stabilized crushed stone base has higher late intensity, late performance and better crack resistance and antifreeze performance, it has been more and more commonly in use in highways construction. However, due to overload and lack of experience in highway design, construction, management and maintenance, the increasing of the damage area, the widening scope and ahead of overhaul period, the traveling capacity and speed is greatly reduced. In 2006, the overhauling is organized in Beijing-Fuzhou Expressway connecting South DeZhou after it is opened to travel. Therefore, relying on the overhauling in Beijing-Fuzhou Expressway connecting South DeZhou, the paper carries out a series of studies. The paper is totally divided into six chapters.The first chapter is the introduction to the Beijing-Fuzhou Expressway DeZhou Southern linking project. In addition, the damage status is conducted and the analysis is made on the damage reason. Also, the drill core samples are conducted on the more serious damaged sections. Then, the chapter introduces the study situation to the Lime fly-ash stabilized crushed stone and the comparison is made on the Lime fly-ash stabilized crushed stone between different units.Chapter two studies the intensity mechanism of Lime fly-ash stabilized crushed stone. And the analysis is made on the water dissociation, carbonation and crystallization of lime. In addition, the analysis is also made on the lime and fly ash reaction and aggregate squeezed. As the base material, lime fly-ash crushed stone should meet certain technique performance requirements. Specific technical performance requirements are introduced in this chapter. Chapter three introduces the performance experiment of the raw materials, such as lime, fly ash and aggregate. And the experiment is carried out in laboratory to obtain the data about the pavement performance of the raw materials. Lime fly-ash crushed stone mixing ratio includes: mixing ratio of Lime fly-ash, Aggregate, Lime fly-ash and aggregate. This chapter carries out experiment separately and obtains that the mixing ratio of lime fly-ash crushed stone is 1:3; the ratio of lime fly-ash to aggregate is 19:81 and the gradation of main aggregate. Then, the specimen preparation is made according to the mixing ratio of lime fly-ash crushed stone to carry out the unconfined compressive strength test. Consequently, the reasonability of mixing ratio of lime fly-ash crushed stone is further verified through the experiment. The standard specimen is prepared for the water stability test and soften coefficient in different age is derived. As temperature and drying shrinkage are the main factors to cause the crack, the paper analyzes the reason for contraction of fly-ash crushed stone mixture. In addition, the paper briefly introduces and carries out the drying shrinkage and temperature shrinkage of the fly-ash crushed stone mixture and the drying and temperature shrinkage coefficient is gained. Therefore, the experiments in the paper provide the basis for the analysis of the anti-contraction of mixture.Chapter four studies the construction control of lime fly-ash crushed stone mixture. Firstly according to the existing climate characteristics in partial areas of Shandong Province, the analysis on temperature changes in DeZhou region is made. Analysis result points out the construction temperature and season in DeZhou region. The proposed value of construction water content is given through the measurement of the water content in an existing highway in DeZhou region. Then, the construction process is studied, a series of construction methods are given including the process control during the mixing of lime fly-ash crushed stone mixture, mixture transport and anti-segregation process control in paving progress, the selection of roller and order and maintenance methods etc. Furthermore, the analysis on influencing factors of compactness is analyzed and discussed. Finally, this chapter analyzes the control methods of compactness. Chapter five is the last chapter. This chapter mainly refers to the conclusions and outlook. The conclusions are drawn and the analysis is made on the factors which are not taken into consideration in the paper through summarizing the work mentioned above. And the paper makes recommendations for the content and methods for further study.