Research On Characteristics Distinguishing And Controlling Means Of The Segregation In Asphalt Mixture

Bituminous pavement has become the primary type of pavement structure for highway in our country. The segregation of asphalt mixture during the construction is one of the main reasons for the damage in the early stage of the asphalt pavement. In recent years, many research organizations at home and aboard have explored extensively research on the segregation of the asphalt mixture which has biggish nominal size during the course of the construction. But these researches mostly concentrate on certain aspects of the segregation. And their conclusions are short of systematism. So the urgent affairs of the development work at present are as follows: to analyze the technical character of the segregation of the asphalt pavement roundly and systematically, to open out the cause of the segregation in the asphalt pavement, to reduce the degree of the segregation of asphalt mixture in the process of the construction, and to effectively assure that the asphalt pavement is holistically homogeneous.With investigation in the course of the construction of many field projects in the stages such as the design, the product process and the spreading of the asphalt mixture, this paper analyzes the reasons that there are the aggregate segregation and the temperature segregation in the asphalt mixture. Using advanced detection device for the pavement detection such as the Pavement Quality Indicator (PQI), the density of the asphalt pavement were set out, and it was demonstrated that the PQI can use in setting out the compactness of the asphalt pavement at a quick speed feasible and reliably. Combining a plenty of local experiment data with indoor test research, and applying the method of the mathematical statistics, and also borrowing ideas from the related research production at home and aboard, it analyzes the technical character of the asphalt pavement which has the aggregate segregation of different degrees, including the surface texture, density, void ratio, Pa (the ratio of the content of the asphalt and the stone), the graduation and so on.. On the base of these things, it puts forward the classification criteria of the aggregate segregation of the asphalt pavement. This paper uses the infrared imagining technique to research the temperature segregation of the asphalt pavement, and analyzes the effect that different temperature brings to the quality of the pavement and many kinds of expressive forms of the temperature distinction of the asphalt pavement after spreading. It is concluded that unified criterion of the temperature segregation in a certain constructional condition is not appropriate.The whole process of design and construction of pavement was researched, including choice of the type of asphalt mixture, aggregation design of asphalt mixture, selection, production and management of primary materials, production, transportation and compaction of asphalt mixture, the running parameters of spreaders, spreading and compacting technology of machines, it studies how to reduce the degree of the happening of the two kinds of segregation of the asphalt pavement effectively in the whole process of the construction, and puts forward several technical controlling measures, and it is demonstrated that the mixture transfer vehicle can bring preferable improvement to the aggregate segregation and the temperature segregation of the asphalt mixture through the case study.According to the different degrees of the segregation of the asphalt pavement, it puts forward the technical measures to reduce the segregation of the asphalt pavement, in order to improving its...