With the rapid development of highway construction in China, asphalt pavements have been widely used in areas with high ultraviolet radiation such as Tibet, Qinghai and Inner Mongolia. During the use of asphalt, due to the action of ultraviolet light in the oxygen and sunlight, aging reactions such as photo-oxidation aging and ozone aging may become brittle and hard, which may affect the low-temperature performance and fatigue durability of the asphalt. Therefore, the light of the asphalt Oxygen aging has received widespread attention. However, there is no corresponding evaluation method for ultraviolet aging of asphalt, and the experimental conditions of ultraviolet aging of asphalt are still worthy of further discussion.
In addition to its chemical composition and trace metal content, the ultraviolet aging properties of asphalt are related to environmental conditions such as ultraviolet radiation intensity, test temperature, influence of water immersion, and thickness of asphalt film. Studies have shown that the photooxidation rate will increase rapidly with the increase of ultraviolet radiation intensity; under the condition of solar radiation, the surface temperature of asphalt pavement generally does not exceed 80 °C. In this range, temperature has no obvious influence on asphalt photooxidation. Asphalt often encounters rainwater and groundwater during use. The immersion water has no obvious effect on the photooxidation of asphalt; the penetration of ultraviolet light decreases sharply with the increase of asphalt film thickness, and the photochemical reaction mainly occurs on the surface layer of asphalt. The ultraviolet aging simulation test of asphalt is a conditional test, and the rationality of the test conditions will affect the validity of the test results.
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