Research On Foamed Asphalt And Foamed Asphalt Cold Recycling Mixtures Pavement Performance

In 21 st century, the highway construction technology is maturing. China’s highway construction has entered a period of rapid growth. At the end of 2013, the total lengths of freeway have 104.5thousand kilometers. In the rapid growth of road construction, road maintenance issues have become increasingly prominent. Road maintenance will generate a lot reclaimed asphalt pavement. Many high grade roadways have been into the period of maintenance and rebuilding. Environmental protection and sustainable development is an important future development direction of the road construction and conservation, the cold recycling technology which used be solved the large amount waste material produced by the maintenance of asphalt surface of the road is more and more favorable in domestic and foreign road construction sectors. Foam asphalt technology both to the economy and environment are very valuable, and it as a cold asphalt binder renewable also attracted wide attention and get new applications.From foamed asphalt and foamed asphalt cold mixture composition point of view, this paper, through data investigation, theories analysis and laboratory test, this thesis systematically study the nature of raw materials, asphalt foaming characteristic and evaluation method, mechanical properties and pavement performances of foamed asphalt cold mixture. So as to optimize its design, improve its various performances and promote relative research and practice for the technology.First, based on the analysis of the principle of asphalt foaming and evaluation, using different grade of asphalt foaming conditions in different laboratory foam tests, analyze effect of asphalt foaming factors analysis and evaluation.Second, this paper intensively studies the foamed asphalt mixture design methods. To compaction test determine the best water pressure and mixing the best real—time moisture content. To combining wet indirect cleavage strength with ratio of dry–and –wet strength determines mixture of asphalt and cement consumption. To water stability as controlling index determines foamed asphalt mixture design.Third, the paper also intensively researches the road performances of foamed bitumen mixture, which include the density, void, indirect tensile strength, unconfined compressive strength, water resistance, high temperature stability and storage performance. The relations between the factors such as grading asphalt content, mixing water content and curing condition and the physical and mechanical performances of foamed asphalt mixture are discussed. The paper put forward effective measures to improve the water stability of foamed asphalt mixture.Finally, this paper summarize the construction of the cold recycling process, and analyze the cold foam asphalt recycling technology benefits the economy and so ciety and demonstrate the practical feasibility of cold foamed asphalt recycling technology.