木质素改性沥青高温性能试验  

Experimental study on performance of lignin-modified asphalt at high temperatures

作　　者：程承[1,2] 陶桂祥 王琦 韩璇祯 CHENG Cheng;TAO Guixiang;WANG Qi;HAN Xuanzhen(Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products, Southwest Forestry University, Kunming 650224, China;College of Civil Engineering, Southwest Forestry University, Kunming 650224, China)

机构地区：[1]西南林业大学云南省木材胶黏剂及胶合制品重点实验室,昆明650224 [2]西南林业大学土木工程学院,昆明650224

出　　处：《林业工程学报》2019年第1期141-147,共7页Journal of Forestry Engineering

基　　金：云南省木材胶黏剂及胶合制品重点实验室开放基金项目(2015007);2015年地方高校国家级大学生创新创业训练计划项目(201510677002)

摘　　要：为研究木质素掺量对沥青结合料高温性能及抗老化性能改善作用的影响规律,以不同木质素掺入量(0%,3%,6%,9%,12%,15%,质量分数)制备沥青试样。采用沥青三大指标及高温动态剪切流变试验,对经过短期老化前后的沥青试样进行三大指标及高温流变性能分析,采用残留针入度比(RPA)、软化点增量(SPI)、延度保留率(DRR)复数剪切模量老化指数(G*AI)及相位角老化指数(δAI)对木质素改性沥青抗老化性能评价。结果表明:随着木质素掺量的增加针入度与相位角δ减小、软化点与复数剪切模量G*升高,表明高温稳定性得到很大改善;延度则出现明显的下降趋势,但在不超过12%时低温性能仍优于基质沥青且满足现行施工要求。车辙因子G*/sinδ变化规律表明木质素掺量超过6%后,沥青高温性能可提升一个等级。经过对比分析沥青各抗老化性能评价指标后发现,木质素的掺加能够延缓基质沥青短期热老化,采用相位角老化指数(δAI)作为评价更为合理。In order to study the effect of lignin content on the properties and aging resistance of asphalt binder at high temperatures,asphalt samples were prepared with different lignin contents (0%,3%,6%,9%,12% and 15%).The examination of three indexes and dynamic shear rheological tests of the asphalt at high temperatures were carried out to analyze the properties of asphalt samples before and after short-term aging.The residual penetration ratio (RPA) and softening point increment (SPI)were used.The ductility retention (DRR) complex shear modulus aging index (G^* AI) and phase angle aging index (δ AI ) were utilized to evaluate the aging resistance of the lignin-modified asphalt.The results showed that,the addition of lignin in asphalt before aging decreased the penetration and phase angle δ,and increased the softening point and complex shear modulus G^*,indicating that the lignin admixture could significantly improve the stability of asphalt at high temperatures.The change of rutting factor G^*/sin δ showed that,when the lignin content exceeded 6%(by weight),the high temperature performance grade of asphalt could be improved by one level.The ductility had a negative effect on the low temperature performance with the increase of the content,but it can meet the requirements of the current construction technical codes when the content was not more than 12%(by weight); The phase angle δ of the lignin-modified asphalt was lower than that of the base asphalt before aging,and the phenomenon was opposite after the short-term aging.It was inferred that the effect of short-term aging on the lignin-modified asphalt.It was not the same as the increase of complex shear modulus G * of matrix asphalt due to the heat aging,but the phenomenon of lignin depolymerization and further crosslinking of asphalt during the short aging.It was shown that lignin could delay the thermal aging of asphalt; Comparing with different evaluation indexes of anti-aging performance,it was found that the phase angle δ could well characterize the varia

关 键 词：木质素 沥青改性 高温流变 短期老化 

分 类 号：TU433[建筑科学—岩土工程]