多聚磷酸改性沥青老化前后高温流变性能

High temperature rheological properties of polyphosphoric acid modified asphalt

基于动态剪切流变(DSR)试验,对老化前后三种改性沥青:多聚磷酸(PPA)改性沥青、苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改性沥青及SBS-PPA复合改性沥青的高温性能进行分析。结果表明:在不同温度及老化作用下,与SBS改性沥青相比,PPA改性剂对沥青高温流变性能的改善更为突出,沥青中黏性成分减小,弹性成分增加。在SBS改性沥青中添加PPA可以明显增强改性沥青的弹性,降低其黏性,SBS-PPA复合改性沥青的高温性能优于SBS改性沥青。在长期老化下,PPA和SBS-PPA复合改性沥青中由储存模量G′占主导作用转变为损失模量G″占主导作用的温度转化点都较高,温度转化点:PPA>SBS-PPASBS。对于SBS改性沥青,温度和频率比老化作用对复数模量G*和相位角δ的影响更大,而PPA和SBS-PPA复合改性沥青受老化影响较大,随着老化程度的加深,可以在较宽的温度和频率范围内保持一定的弹性来抵抗变形。PPA改性沥青在老化前后,不同温度和频率下都具有较高的车辙因子G*/sinδ,且老化后G*/sinδ增加的最多,高温抗车辙能力更强,其次是SBS-PPA复合改性沥青。

Based on the dynamic shear rheological test（DSR）,the high temperature performance of three kinds of polymer modified asphalt before and after aging：polyphosphoric acid（PPA）modified asphalt,styrene butadiene styrene block copolymer（SBS）modified asphalt and SBS-PPA modified asphalt were analyzed.Results shows that：Under different temperatures and different aging,compared with SBS modified asphalt,the improvement of rheological properties of asphalt at high temperature was more prominent with PPA modifier,the viscosity of asphalt decreases and the elastic component increases.PPA was added in the SBS modified asphalt can obviously improve the elasticity of modified asphalt and reduce its viscosity.The high temperature performance of SBS-PPA modified asphalt is better than that of SBS modified asphalt.Under the long-term aging,the temperature translation point of PPA and SBS-PPA modified asphalt by the storage modulus G′dominant role into the loss modulus G″dominant role become higher,the temperature translation point：PPA〉SBS-PPASBS.For SBS modified asphalt,the effect of temperature and frequency on G＊andδare greater than that of aging,but the PPA and SBS-PPA modified asphalt are greatly influenced by aging.As the aging degree of deepening,can the PPA and SBS-PPA modified asphalt maintain a certain degree of flexible to resist deformation in relatively wide temperature and frequency range.PPA modified asphalt before and after aging under different temperatures and frequency have a higher G＊/sinδ,and the G＊/sinδincreases most after aging,high temperature anti rutting ability becomes stronger,followed by SBS-PPA modified asphalt.