Research On Constructing Semi-flexible Pavement By Cold In-Place Recycling Of Asphalt Pavement

Cold in-place recycling stability technology of asphalt pavement is advanced maintenance method abroad, which is environment protecting, economical and energy saving. China has recently tried to introduce this technology, however, it lacks systemic research and standardization, including recycling preparation of cold recycling asphalt pavement, mixture composing design, performance evaluation, construction technology, parameters and methods of asphalt pavement structure design, etc. Based on the latest researches home and abroad, combining with State Highway G324—Baise to Pingban in Guangxi Province overhauling construction projects, research on foamed asphalt as the main target about cold recycling stability technology of asphalt pavement was carry out in this paper.First of all, the standards of recycling preparation and new materials about cold recycling technology were studied in this paper. Research on foamed asphalt as the main target, the micro structure and recycling principle of cold recycling mixture of asphalt pavement were studied, the foaming technology and its influencing factors were analysed in this paper, and the influence of foaming preparation to asphalt foaming and mixture performance was studied for the first time, and also the research on foaming performance based on the mechanical performance of the mixture. The standards and the performance evaluation of the emulsified asphalt for cold recycling and its cement additive were discussed briefly.Then, cold recycling mixture composing design of asphalt pavement and its road performance were studied here. All kinds of design parameters and its influence to foamed asphalt mixture were studied, including mixture composing design. By analysing the forming mechanism of foamed asphalt mixture, three important stages of its mechanism increase were studied. After that, the water stability and high temperature stability of the mixture were studied, and the crack resistance and the fatigue character that analysed statistically were studied for the first time.Then, to determine the controlling parameters, construction control was studied in the cold recycling project of asphalt pavement, combining with State Highway G324—Baise to Pingban in Guangxi Province overhauling construction projects.Finally, the design parameters and the typical structure design of cold recycling half-flexible pavement structure of asphalt pavement were studied. The recommending values of Ks, ITS, resilient modulus and the composing model of cold recycling asphalt pavement structure with its typical structure list for thickness calculation were studied for the first time.