Research On Paving Technology Of Foam Asphalt Stabilizing Old Pavement Material

Many high-grade highways have been or are being into the large, medium repair period. The traditional method of repairing the semi-rigid base tructural disease is to excavating the old asphalt surface layer and all the old base, and then rebuilding the semi-rigid asphalt pavement or flexible base asphalt pavement, so that there must be high project cost, longer construction period, serious impact on traffic, and at the same time,there will have many disposible pavement materials (including the old asphalt pavement materials, the old base materials, etc.), which brings the old disposed materials and cauces environmental pollution.As compared with the traditional renovation methods, foam asphalt stability of the old road surface materials technology has great advantages. The technology is formed by adding the original milling materials of asphalt surface for the aggregate, or adding some new aggregate, and then adding other admixtures mixed together. Because of the adding of asphalt, the elastic modulus of semi-flexible base is between that of semi-rigid base and flexible base, and at the same time, foam asphalt semi-flexible base has a certain anti-deformation capability, which can effectively delay the reflection cracks of the semi-rigid base.By the interior pilot study on foam asphalt and foam bituminous mixture, the paper draws the best conditions for asphalt foaming, suiTab. gradation range, compressive strength and other design parameters. It analyses different cement contents, forming ways, curing conditions and different ages and which impact on the intensity. Through observating, testing and performance analysing of the test road, it sdudies the key process technology and construction quality controling methods of the asphalt pavement structure of foam asphalt semi-flexible.Finally, the paper analyses the social and economic benefits of foam asphalt stability of the old road surface materials technology.