多聚磷酸对沥青高低温性能和老化性能的影响

采用不同掺量多聚磷酸（PPA）对沥青进行改性，研究了PPA对沥青高低温性能和老化性能的影响，并借助化学组分和红外光谱测试分析了PPA改性沥青的老化机理。结果表明：随着PPA掺量增加，沥青的软化点和粘度升高，弗拉斯脆点向低温移动，沥青的高低温性能均得到改善。与未改性沥青相比，PPA改性沥青在短期热老化、长期热老化和紫外老化后的软化点增量、粘度老化指数和弗拉斯脆点变化量均明显减小，针入度保留率和延度保留率大幅提高。化学组分和红外光谱分析发现PPA促进了胶质向沥青质的转变，减少了沥青中易发生老化反应的活性组分，使老化过程中改性沥青的脂肪族、芳香族、羰基和亚砜基指数的变化量均明显减小，从而具有优良的抗老化性能。

Effects of Polyphosphoric Acid on High-low Temperature Properties and Aging Properties of Asphalt

The asphalt was modified with different amount of polyphosphoric acid (PPA), and the effects of PPA on the high-low temperature properties and aging properties of asphalt were studied, aging mechanism of PPA modified asphalt were analyzed by the means of chemical composition analysis and Fourier transform infrared spectroscopy (FTIR). The results show that with the increase of PPA dosage, the softening point and viscosity of the modified asphalt gradually increased, while the Fraass breaking point moved to the low temperature direction. The high and low temperature performance of modified asphalt was significantly improved. Compared with matrix asphalt, the softening point increment, viscosity aging index and Fraass breaking point increment of PPA modified asphalt are obviously reduced after short-term thermal aging, long-term thermal aging and ultraviolet light aging, the penetration retention and ductility retention are significantly increased. The results of chemical composition analysis and FTIR indicate that PPA is able to promote the transformation of asphalt from resins to asphaltenes, and reduce the active components which prone to take place aging reactions in asphalt. The changes of aliphatic group, aromatic group, carbonyl group and sulfoxide group index of PPA modified asphalt in aging process are remarkably reduced, thereby possessing excellent anti-aging performance.