基于测力延度试验的机场SBS改性沥青热储存性能分析

Analysis of thermal storage performance of SBS modified asphalt for airport pavement based on force-ductility tests

采用室内烘箱模拟沥青储罐对SBS改性沥青热储存性能影响规律及机理,对不同热储存时间的SBS改性沥青进行了RTFOT老化前后三大指标、黏度指标以及测力延度指标测试,分析各指标与热储存时间的关系,并通过测力延度试验分析揭示了三大指标、黏度指标变化的原因。结果表明,随SBS改性沥青热储存时间延长,RTFOT老化前后沥青针入度、软化点、5℃延度均减小,布氏黏度、测力延度曲线峰力值F_(0)、转折点拉力F_(1)、断裂拉力F_(2)均增大,RTFOT老化后SBS改性沥青各指标进一步劣化,劣化主要由基质沥青及SBS网络节点变化导致。测力延度试验拉伸柔量指标f与热储存时间呈较好的负相关,可作为评价沥青热储存性能的关键指标。

The rule and mechanism of influence of asphalt storage tank on heat storage performance of SBS modified asphalt were simulated in a laboratory oven.The three indexes,viscosity index and force ductility index of SBS modified asphalt with different heat storage time were tested before and after RTFOT aging,and the relationship between each index and the heat storage time was analyzed.The causes for the change of the three indexes and the viscosity index were revealed through the force ductility test.The results showed that,with the prolongation of the heat storage time of SBS modified asphalt,the penetration,softening point and 5℃ductility of SBS modified asphalt before and after RTFOT aging decreased while the Brinell viscosity,peak force of force ductility curve,F_(0),turning point tension,F_(1),and breaking tension,F_(2),increased.The indexes of SBS modified asphalt after RTFOT aging deteriorated further,which was mainly caused by the change of base asphalt and SBS network nodes.The tensile compliance index,f,in the force ductility test has a good negative correlation with the heat storage time,which can be used as a key indicator to evaluate the heat storage performance of asphalt.