论文部分内容阅读
为了研究沥青胶浆的疲劳及自愈合特性,利用动态剪切流变仪(DSR)进行时间扫描及疲劳—愈合—再疲劳测试,并通过原子力显微镜(AFM)对细观结构进行观测,比较分析了不同粉胶比下基质沥青胶浆和SBS改性沥青胶浆的疲劳性能,以及在常温(25℃)下,3个不同间歇期的自愈合性能。试验发现:SBS沥青胶浆具有更好的疲劳和自愈合性能,两种沥青胶浆疲劳寿命均随粉胶比的增大而增加,同一粉胶比条件下,更长的间歇期有利于其自愈合,过大或者过小的粉胶比都会降低沥青胶浆的自愈合性能;原子力显微镜(AFM)观测结果表明基质沥青胶浆出现明显的“蜂状结构”,粉胶比增加,矿粉吸附更多的沥青质,“蜂状结构”变多,与沥青界面内聚力作用增强,提高了抗疲劳性能,SBS改性剂与沥青相容性良好,改性沥青胶浆没有出现“蜂状结构”,改性剂的加入大大增强了分子间内聚力,有助于提高抗疲劳性能,因此建议路面材料选用改性沥青胶浆。
In order to study the fatigue and self-healing properties of asphalt mortars, time-sweep and fatigue-healing-reattachment tests were performed with Dynamic Shear Rheometer (DSR). Microstructure was observed by atomic force microscopy (AFM) The fatigue properties of matrix asphalt mortar and SBS modified asphalt mortar under different cementing ratios were analyzed, and the self-healing properties at room temperature (25 ℃) for three different intermittent periods were analyzed. It was found that SBS asphalt mortar had better fatigue and self-healing properties. The fatigue life of both asphalt mortars increased with the increase of the ratio of powder to binder. Self-healing, too large or too small powder-cement ratio will reduce the self-healing properties of asphalt mortar; atomic force microscopy (AFM) observations showed that the matrix asphalt mortar obvious “bee structure” , Mineral powder adsorbed more asphaltenes, “bee-like structure” increased, and bitumen interface cohesion enhanced, improved fatigue resistance, SBS modifier and asphalt compatibility is good, modified asphalt mortar did not appear “ Honeycomb structure ”, modifier added greatly enhances the intermolecular cohesion, helps to improve anti-fatigue performance, it is recommended to use modified asphalt pavement material mortar.