The Research On Pavement Asphalt Composite Anti-aging Agent

Pavement asphalt is one of the most important materials in road construction, itsresearch, development and production has attracted world attention. Asphalt aging hasa significant impact on the use performance of asphalt pavement, and it will shortenthe useful life of the pavement. Particularly asphalt pavement during the serviceperiod, subjects to the ultraviolet radiation in sunlight and photo-aging, resulting inthe deterioration of asphalt pavement, seriously affecting the road performance andservice life of the asphalt pavement. Therefore, the study of asphalt’s anti-agingmeans in order to extend the useful life of the asphalt pavement becomes an importantresearch content in present.This paper uses the conventional performance indicators:penetration, softening point,ductility testing, infrared spectroscopy (FTIR) and thermo gravimetric differentialthermal analysis (TG-DTA) to analyse the macroscopic properties and microstructureof asphalt before and after the ultraviolet light aging. And make experiments on themain factors: illumination time, the experimental temperature, the asphalt film thickand the simulated precipitation which will affect asphalt ultraviolet light aging. Theexperimental results show that: with the extension of exposure time and the increaseof experimental temperature, the asphalt aging degree becomes more severity; withthe asphalt film thickness increasing, the aging of the asphalt weakened, especiallywhen it is greater than 1.2mm, the slewing rate of asphalt performances change little.It indicates that the UV aging of the asphalt occurs only in the asphalt surface layerabout 1mm; the simulated precipitation pH value is smaller, the greater the damage tothe asphalt pavement.On this basis, determined the relatively serious ultraviolet lightaging environment of asphalt by orthogonal test.By using different kind and different dosage of additives to improve the anti-agingeffects of asphalt, the test results show that: the mixing of different anti-aging agentcould significantly improve the anti UV aging properties of asphalt, and compoundcombination of 5% A+1.5% D as a new type of composite anti-aging agent caneffectively improve the anti-aging effect of asphalt. Through video microscope,infrared spectrum detection and TG-DTA analysis,we analyze and study the compositeanti-aging agent on improving the asphalt anti-ultraviolet aging properties from themicroscopic structure. This article builds a asphalt aging dynamics model by researching the asphaltsoftening point changing with illumination time and test temperature.It indicates thatthe aging of the asphalt belongs to the level 1 reaction .We obtain its aging dynamicsparameters, make further study of the process of asphalt UV light aging, and makedeeper study of asphalt UV-aging mechanism, the mechanism of anti-aging agent onimproving asphalt anti-ultraviolet aging properties.