Study On Thermal Recycled Asphalt Mixture Old Material Content And Low Temperature Performance Evaluation

After decades of development, Chinese road infrastructure construction has become more perfect, the early highway of the construction has moved into the large, medium repair and maintenance phase, which will produce a lot of waste asphalt mixture. To conserve resources, it rationally uses waste asphalt pavement materials, achieving limited-energy recycling usage, which is in line with the basic policy of the current environmental protection and energy saving. Recycling technology in mind is to save resources, re-use waste asphalt pavement materials, which the more old asphalt pavement material content is saving more resources, but the heat recycled asphalt mixture at low temperature crack resistance is decreased, if the regenerated pavement material cracking resistance do not meet the requirement of use area, so it not only cannot achieve the original intention, but will also result in huge losses. Therefore, this article will be recycled asphalt mixture reasonable old material blending ratio and low temperature evaluation indicator properties more in-depth study.To find relatively reasonable thermal regeneration asphalt mixture blending ratio of old material, the use of rheological principle in the United States SHRP test methods, the introduction of rutting factor, the fatigue factor, low creep rate and creep stiffness four indexes to high-temperature resistance to deformation, fatigue durability and low temperature crack resistance of four different new and old blending proportion of recycled asphalt evaluation and analysis, at both high and low temperature performance situation makes reasonable old asphalt and new asphalt blending ratio, and then get the reasonable old material content of thermal regeneration asphalt mixture, to make thermal regeneration asphalt mixture ratio design and road performance test, to prove that the method is reasonable to get a reasonable old material content by controlling the blending proportion of new asphalt and old asphalt from renewable asphalt.The comparative analysis of low temperature Xiaoliang bending test and at home and abroad more advanced constrained specimen thermal stress, by different thermal recycling asphalt mixture experiment, to explore the correlation of these two trials low temperature performance evaluation indexes, using regression analysis can get the best correlation of freeze-off temperature and low temperature Xiaoliang bending failure strain. By supplying asphalt mixture test to obtain the correspondence between the freezing-off temperature and low failure strain, the reference with Superpave PG grade of US SHRP program thinking, as well as asphalt pavement interlayer difference temperature, to calculate the temperature of asphalt pavement different layers, the first time can offer the freeze-off temperature evaluation index of the low temperature performance of recycled asphalt mixture, and frozen permafrost areas the asphalt pavement freeze-off temperature and low-temperature bending technical requirements.