为了改善高海拔高辐射寒冷区沥青混凝土的抗老化性能,按照室内与高寒高海拔区热、紫外光辐射总量相等的原则进行室内多聚磷酸改性(PPA)沥青及其混合料模拟老化试验,进而研究了PPA及PPA与低剂量SBS、SBR聚合物改性沥青抗热老化和紫外光老化性能,并将热老化、紫外光老化后多聚磷酸改性沥青混合料的路用性能、疲劳性能与基质沥青及4.5%SBS改性沥青混合料进行了对比.试验结果表明:PPA与聚合物改性沥青的5 ℃延度指标随热老化与紫外光老化时间增大而减小,抗车辙因子和软化点均随紫外光老化时间增加而增大,热老化5 h后延度趋于稳定,紫外光老化12 h后延度趋于稳定.随着紫外光老化时间延长,PPA及PPA复合改性沥青混合料高温性能呈先增大后减小的趋势,低温抗裂和疲劳性能随老化时间延长呈下降趋势,紫外光对沥青高低温性能的劣化作用比热老化突出.PPA对基质沥青和低剂量SBS、SBR改性沥青混合料抗紫外光老化作用改善效果显著,PPA可作为高紫外光辐射区沥青路面抗老化剂使用.研究成果可为拓展PPA改性沥青及PPA与低剂量聚合物复合改性沥青在高原高温差、高紫外光辐射区的推广应用提供参考与借鉴.%In order to improve the anti-aging performance of asphalt concrete in high altitude and high radiation cold area,indoor polyphosphoric acid modified (PPA) asphalt and its mixture were simulated according to the principle of indoor and alpine high altitude area equal to total heat and ultraviolet radiation.Aging properties of PPA,PPA and low-molecular-weight SBS,SBR polymer-modified asphalt were studied,and the road performance of PAH-modified asphalt mixture after heat aging and UV aging was studied.,And the fatigue performance was compared with that of matrix asphalt and 4.5% SBS modified asphalt mixture.The experimental results show that the 5 ℃ ductility index of PPA and polymer modified asphalt decreases with the aging time and the aging time,and the rutting factor and softening point increase with the aging time of ultraviolet light,5 h,the ductility became sTable,and after 12 h UV aging,the ductility became sTable.With the aging time prolonged,the high temperature performance of PPA and PPA composite modified asphalt mixture firstly increased and then decreased,and the low temperature crack resistance and fatigue performance decreased with the aging time prolonged.The UV-Of the deterioration of aging than the thermal aging.PPA can improve the anti-ultraviolet aging effect of the asphalt and low-dosage SBS and SBR modified asphalt mixture,and PPA can be used as the anti-aging agent of the asphalt pavement in the high ultraviolet radiation area.The research results can provide references for the popularization and application of PPA modified asphalt,PPA and low-dosage polymer compound modified asphalt in the high temperature difference and high ultraviolet radiation region of the plateau.
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