The Research On The Temperature Control Over The Construction Of Asphalt Mixtures

With the reform and opening policy, transportations and communications in China have enjoyed a rapid development. Both land and water communications have attracted worldwide attention. Although the rate of pavement, with asphalt as its main surface structure, has been increased dramatically, the asphalt pavement is liable to suffer from such damages at the beginning of its services as rut, groove (porosity). These problems, always being a vexation to highway constructionists, have become problems demanding prompt solution. Researchers have made great efforts to solve the problem of early damages on asphalt pavement. However, those researches mainly focus on how to improve such properties of asphalt mixture as the grading of asphalt mixture, modifier bitumen,SMA, and so on, while the construction temperature of asphalt mixture has been given little attention.The early damages on asphalt pavement have a close correlation with construction temperature of asphalt mixture. During the process of asphalt pavement, the property and durability of asphalt pavement is closely related to heating temperature, storing temperature of asphalt, heating temperature of minerals, mixing temperature, preliminary temperature, paving temperature and rolling temperature of asphalt mixture. If constructed under too high temperature, asphalt will suffer from serious aging, which, in turn, will shorten the life expectancy of pavement; if constructed under too low temperature, pressure degree on pavement will not be enough, which, in turn, will lead to water damage and rut at the beginning of its service. Taking the above-mentioned into consideration, it is safe to say that it is quite necessary to do a research on construction temperature of asphalt pavement in order to specify construction, find a favorable temperature for construction and increase the durability of asphalt pavement.Based on real construction and indoor experiments on asphalt and asphalt mixture, this thesis will discuss how to improve the durability of asphalt pavement. The study will be made in the following scopes:The study on heating-caused aging of asphalt:Experiments have been made on various heating temperature and storing temperature of asphalt, so the most favorable heating temperature and time have been concluded.The study on construction temperature of asphalt mixture:Experiments have been made on qualities of asphalt mixture under different mixing temperature, so the most favorable mixing and rolling temperature of asphalt mixture have been concluded.