Research On Aging And Regeneration Performance Index Under Five Times Recycling Of Asphalt And Its Microsfic Analysis

As the rapid development of economy in our country, the high grade pavement of asphalt is already exists in generally. Compared with the cement concrete pavement, asphalt pavement has smooth surface, no joint, less dusty, convenient maintenance and fast opening traffic. Because of the advantages of comfortable driving and simplicity maintenance, asphalt pavement is adopted more frequently.However, the asphalt pavement need a large and medium repairment after a certain period used because its defects such as strong sensitive temperature, volatile soft in High temperature, volatile brittle hardening in low temperature.This will not only waste bituminous concrete, but also the mixture of gases pollute the environment in mixing and spreading paving asphalt. It is contrary to the development pattern of "resource-saving and environment friendly" which is advocated in our country at present. For the purpose of spreading asphalt concrete pavement and built the "resource-saving and environment-friendly" society, it is already urgent to inquiry mechanism of asphalt aging and reproduce asphalt with some of the advanced production technology and equipment. This is begin with simulation of asphalt aging,testing asphalt performance indicators and analysis asphalt aging mechanism.And then, the added value of the best regeneration agent is found by the comparison of multiple regeneration effects and test the performance index of the regeneration by the way. It draw a conclusion that asphalt penetration decreases,softening point increases, ductility value decreases gradually in following with the increasing of aging time and times. The properties of the asphalt can be roughly recovered to the level of the aging by using the regenerated agent to regenerate the aging asphalt once and for many times. At the same time, it is further known and verified the asphalt oxygen oxidation and component changes after aging by microcosmic analysis and study the asphalt aging and regeneration of the micro information by with using of FTIR and atomic force microscopy.By comparing the test data and structural change analysis, infrared spectrum curves show that the C-H groups in asphalt are oxidized to carbonyl groups C=O and S elements were oxidized to sulfoxide radicals with thin film oven in the simulation of asphalt aging. With the increasing of aging time and times, the content of carbonyl and carbonyl group increased gradually and the content of C=O and S=O groups wasdecreased in the asphalt. But the asphalt in many aging regeneration process, the first and second regeneration of carbonyl and sulfoxide groups is not less than the first and second aging which draw a conclusion that regeneration is not aging process of the reverse reaction. The atomic force microscope picture shows that the content of asphalt increases after aging and the content of asphalt content decreases that is meet the change law of four component of asphalt aging.From both macro and micro aspects of to explore the asphalt aging mechanism of regeneration, the combination of macro and micro, it provides a new path for the study of asphalt aging regeneration and provides a very valuable theoretical basis of asphalt deep understanding and exploitation.