紫外光老化对水性环氧-SBR乳化沥青高温性能影响研究

Influence of Ultraviolet Aging on High-Temperature Properties of Waterborne Epoxy-SBR Emulsified Asphalt

采用室内加速紫外光老化试验研究紫外光老化后水性环氧-SBR乳化沥青(waterborne epoxy-SBR emulsified asphalt,WESEA)的高温性能,探究WESEA胶结料经紫外光老化后表面形貌、高温流变性能及蠕变性能变化规律,并采用红外光谱分析紫外光老化前后材料官能团变化特征。结果表明:随着水性环氧掺量增加,WESEA胶结料原样和经不同时长紫外光老化后胶结料的复数剪切模量G^(*)、车辙因子(G^(*)/sinδ)、平均弹性恢复率γ_(rec)均呈增长趋势,相位角δ、不可恢复蠕变柔量Jnr降低,复数剪切模量老化指数G_(AI)^(*)均大于1,说明水性环氧增加了WESEA胶结料中弹性成分,有效改善了胶结料的高温流变性能,提高了胶结料的抗剪切变形能力;WESEA胶结料经相同时长紫外老化后,官能团老化指数C_(I)′(羰基C=O)与S_(I)′(亚砜基S=O)随水性环氧掺量增加而减小,B_(I)′(丁二烯基C=C)相近,表明水性环氧可以有效抑制WESEA胶结料中基质沥青氧化反应及SBR胶乳降解,延缓WESEA胶结料紫外光老化进程;水性环氧可有效改善胶结料抗紫外光老化的高温性能。

The high-temperature properties of waterborne epoxy-SBR emulsified asphalt(WESEA)after ultraviolet aging was investigated by indoor accelerated ultraviolet light aging test.The variation law of surface morphology,high-temperature rheological properties and creep properties of WESEA binder after UV aging was explored,and the changes of WESEA binder functional groups before and after ultraviolet light aging were analyzed through infrared spectroscopy.The results show that as the content of waterborne epoxy increases,the complex shear modulus G^(*),rutting factor(G^(*)/sinδ),and average elastic recovery rate γ_(rec) of the original WESEA binder and the binder after different durations of UV aging all show an increasing trend.The phase angleδand irrecoverable creep compliance J_(nr) decreases,and the complex shear modulus aging index G_(AI)^(*) is greater than 1,indicating that waterborne epoxy increases the elastic composition of WESEA binder,effectively improves the high-temperature rheological properties of binder,and enhances the shear deformation resistance of binder.After the same UV aging duration,the functional group aging index C_(I)′(carbonyl C=O)and S_(I)′(sulfoxide S=O)of WESEA binder decrease with the increase of waterborne epoxy content,but B_(I)′(butadienyl C=C)is similar,indicating that waterborne epoxy can effectively inhibit the oxidation reaction of the matrix asphalt and degradation of SBR latex in WESEA binder,consequently delay the UV aging process of the WESEA binder.Therefore,waterborne epoxy can effectively improve the high-temperature performance of bonding materials against UV aging.