| Owing to superior performance and driving comfort, asphalt pavements account for a large proportion in highways and city roads. However, after aged by the natural environment, physical and mechanical properties of asphalt mixture will become worse until it can not meet the requirements of the traffic load. Thus, the aging of the asphalt is an important factor affecting performance and researched and how to delay aging, reduce the aging of measures proposed is particularly important.In this paper, we do RTFOT aging test of different time and summary aging changes of each indicator. Penetration gradually decay in the way of index, softening point increase in linear, the relations between viscosity of different time and temperature is saal curve. Penetration, softening point, viscosity changes with aging time show that temperature sensitivity of asphalt and low temperature crack resistance is getting worse with the aging time extended. The four components tests show that asphaltene, colloid increase and saturates, aromatic decrease with the aging time extended. This illustrate in microscopic that the aging is due to the light oil volatile and into heavy oil.The article also test the indicators of asphalt extracted from old road, then establish the relationship between laboratory simulation aging and the length of road service, eventually proposed the measures of slow down aging. Reducing agent added to the old asphalt and test its indicators, then evaluate the effect of reducing agent. Do RTFOT aging test to reducing asphalt, compare different indicators between restoring asphalt with different aging time and new asphalt, then evaluate the anti-aging properties of reducing agent. |
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