生物油再生沥青胶结料路用性能分析

Pavement Properties of Bio-oil Rejuvenated Asphalt Binder

为研究生物油再生沥青胶结料的路用性能,分析比较了基质沥青与生物油再生沥青胶结料的流变性质与化学特性。首先通过三大指标与黏度测试确定生物油在老化沥青中的最佳掺量;之后重点分析最佳生物油掺量下再生沥青与基质沥青的高温与疲劳性能,高温性能通过多应力蠕变回复试验(MSCR)测试,疲劳性能通过DSR时间扫描测试;最后利用红外光谱(FTIR)和凝胶渗透色谱(GPC)测试分析2种沥青的化学特性。研究结果表明:10%生物油可恢复老化沥青针入度与延度至基质沥青水平;基质沥青与10%生物油再生沥青的PG分级分别为PG64-16与PG70-16;MSCR结果表明再生沥青相比基质沥青具有较好的高温性能;N_(f50)指标表明再生沥青的抗疲劳性能较基质沥青胶结料更好,因为2种沥青模量相近,再生沥青的弹性组分含量更高;FTIR结果表明生物油稀释了老化沥青中高极性的亚砜基;GPC结果表明生物油降低了老化沥青中的大分子和小分子含量,改善了老化沥青分子量分散度。生物油改善了老化沥青的路用性能和化学特性,是一种较有潜力的沥青再生剂。

To investigate the pavement properties of bio-oil rejuvenated asphalt,the rheological properties and chemical characterization of virgin and rejuvenated asphalt binders were compared.First,the optimum content of bio-oil in aged asphalt was determined by using penetration,softening point,ductility,and rotary viscosity tests.Second,the rutting and fatigue properties of bio-oil rejuvenated and virgin asphalt binders were analyzed,with the rutting property tested via a multi-stress creep recovery test(MSCR)and the fatigue property tested by using a dynamic shear rheometer time sweep.Finally,the chemical characterization of asphalt binders was analyzed by Fourier-transform infrared spectrometry(FTIR)and gel permeation chromatography(GPC).The results show that with a dosage of 10%bio-oil,aged asphalt penetration and ductility are recovered to the level of virgin asphalt.Virgin asphalt and rejuvenated asphalt with 10%bio-oil are PG64-16 and PG70-16,respectively.MSCR results indicate that rejuvenated asphalt has a better rutting property than virgin asphalt.Nf50 results indicate that rejuvenated asphalt has a better fatigue property than virgin asphalt because rejuvenated asphalt has a higher elastic composition content with a similar modulus.FTIR results indicate that the sulfoxide group with high polarity in aged asphalt is diluted by bio-oil.GPC results indicate that the large molecule size(LMS)and small molecule size(SMS)dosages of aged asphalt are decreased by bio-oil,and the molecular weight polydispersity of aged asphalt is improved by bio-oil.Bio-oil exhibits the potential of being a promising rejuvenator owing to its effective improvement of pavement properties and chemical characterization of aged asphalt.