多聚磷酸对沥青性能影响研究

摘要

以不同掺量多聚磷酸(PPA)制备改性沥青,并对多聚磷酸改性沥青常规性能指标以及流变性能进行分析,结果表明多聚磷酸的掺入能够提高沥青软化点和脆点,增大沥青的车辙因子,提升沥青高温等级,但会降低蠕变率,损害沥青低温性能,多聚磷酸加入量过高,沥青黏度过大,不利于沥青泵送及拌合,通过分析沥青四组分的变化,对多聚磷酸改性机理进行了初步探索,多聚磷酸的加入促使沥青中的饱和分和胶质向沥青质转化,从而影响沥青的高低温性能.%Modified asphalt was prepared with polyphosphoric acid(PPA)of different dosages, and the conventional properties and rheological properties of the PPA modified asphalt were analyzed. The results show that the softening point and brittle point of the PPA modified asphalt increase with the incorporation of PPA. Besides, the PPA can increase the rutting factor of asphalt, improving the high temperature grade while reducing the creep rate, damaging the low-temperature performance. Excessive amount of PPA can lead to high viscosity, which is adverse to pumping and mixing of asphalt. The modification mechanism of PPA was studied by analyzing the change of four components of asphalt. The results show that the addition of PPA can promote the conversion of saturation fraction and resin of asphalt to asphaltene, which affects the high and low temperature properties of asphalt.