关键词: 道路工程；沥青；紫外老化；宏观性能；微观组成

Abstract: Dynamic shear rheological test and multiple stress recovery creep test were used to measure the high temperature rheological properties of ultraviolet (UV) aged asphalt. Meanwhile, the component composition test, element composition test, gel permeation chromatography test and infrared spectrum test were used to measure the changes of microscopic composition such as component composition, element composition, molecular weight distribution, characteristic peaks and functional groups of asphalt. The variation rules of macro and micro aging behavior of asphalt under ultraviolet radiation and its evaluation indicators were studied. The results show that after UV aging, the rutting factor and unrecoverable compliance of asphalt are increased, the phase angle and recovery rate are decreased, and the high-temperature stability is increased. At the same time, as a polymer material, asphalt breaks its internal chemical bonds and long chain and branch chain molecules under the action of ultraviolet, and oxidizes under the action of oxygen, which increases the asphaltene and converts the asphalt structure to gel type. After UV aging, the molecular weight distribution of asphalt becomes narrower, and there is a phenomenon of small molecules continuously aggregating into large molecule compounds inside, causing changes in characteristic peaks and the production of carbonyl and sulfoxide functional groups. It is found that the rutting factor and recovery rate can be used as the evaluation indicators of high-temperature rheological properties of asphalt UV aging, while carbonyl and sulfoxide functional groups can be used as the indicators of aging generation and anti-aging ability, respectively.

Key words: highway engineering; asphalt; UV aging; macro properties; micro composition