| In recent years, with the lone-life bitumen pavement design theory issued，in theconstruction process of high-grade highway requirement to the durability of bitumenbecome higher and higher. But bitumen is organic material, as is known to all thatorganic materials are easy to aging under the action of natural environment of heat,light, Oxygen. Lot of diseases caused by ageing of bitumen such as cracking, downpunching, grooving and so on, shorten the life of the bitumen pavement greatly. Inorder to prolonged the life of bitumen pavement, we must figure out the variation ofthe components and structure during the bitumen aging and anti-aging process.infrared spectroscopy is one of the most important and effective experimentalmethods to research into Bitumen composition and its molecular structure. butbecause of the complexity of the bitumen components and structure, such problems asevaluation standard is not unified and evaluation system chaos are existed until now.In this paper, according to a variety of different bitumen and improved bitumen, wesystematicly studyed into the Fourier Transform Infrared Spectroscopy (FTIR).usedas bitumen evaluations to announce the relationship and rules between the bitumenphysical properties、components and molecular structure. The main conclusions are asfollows:(1)Based on the total peak area of bitumen full spectrum (4000~700cm-1)、groups stretching vibration area (4000~1400cm-1)、fingerprint area (1400~700cm-1)and saturated C-H stretching vibration area (3000-2800cm-1)， calculating andanalysis the group index of the main functional groups. Find that the relative contentsof functional groups based on4000~700cm-1full spectrum peak area, can mostcorrectly reflect the law between group content and bitumen physical properties.(2)After short-term hot oxygen aging and short-term ultraviolet aging in the lab,the peak area of carbonyl and sulfoxide in bitumen change different, the single peakarea of carbonyl is fit to evaluate the Short-term aging behavior of bitumen, but thepeak area of carbonyl and sulfoxide increase with the increase of time to the PAVaging of bitumen, it is accurate to use the total peak area of carbonyl and sulfoxide to evaluate the Long-term aging behavior of bitumen.(3)Through the research of four components analytical method，we find that aftertaking different aging methods the variation of saturates, aromatics and asphaltenesare the same. The chain of saturates break or oxidation in the aging process,polycondensation reaction take place in aromatics forming cyclic compounds，resinsin the bitumen reveals different in different aging ways: In thermal oxidative agingWAR'Wn≥4both increase, formation of more large molecular aromatic cycles, inother words, it transferred to asphaltenes. In UV aging WAR'Wn≥4all the same，mainly for the change rate of sulfoxide index is increase，indicate that in the UVaging process, impurity atom in the resins are oxidized.(4)LDHs has multistage stratified structure, multistage layer plate and betweenthe layers can produce multiple absorption and shielding of UV,therefor it cut off theUV.OMMT also has the same stratified structure, OMMT lamellar can prevent theoxygen proliferation in the bitumen, so can inhibit bitumen aging. ultraviolet absorberabsorb the UV to avoid or reduce the UV direct damage to the bitumen molecular. Bythe method of full spectrum Standards, evaluated the functions of LDHs、OMMT andultraviolet absorber during the anti-aging process, and the change of character groupscontents of modified bitumen during aging process, confirmed the reliability of fullspectrum Standards. |
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