摘要
受粘弹特性的影响,沥青的疲劳特性具有特殊性.目前已有研究发现沥青具有自愈性,即荷载停止作用后沥青的模量可以慢慢恢复.因此开展不同荷载作用模式下沥青疲劳特性的研究是十分必要的.文中借助于DSR研究了连续加载模式下沥青的疲劳特性,采用4种沥青疲劳评价指标(50%G*,DER,DR,δ)评价了沥青的疲劳特性,研究了沥青的自愈能力.研究表明:沥青的疲劳性能随着应力的增大而降低.当控制应力较大时,模量随着荷载作用次数的增加而减小;当控制应力较小时,出现硬化现象.50%G*,DER,DR,δ这几种疲劳寿命评价指标均存在一定的不足.沥青的自愈性对沥青的疲劳特性有重要影响.荷载停止作用初期,沥青模量的恢复程度较大.当时间足够长时,沥青的模量可以恢复到初始模量,但粘弹比例发生了变化.
Fatigue has been one of the hot topics all the time in the world.The fatigue characteristic of asphalt has particularity because of its viscoelasticity characteristic.At present,the healing characteristic of asphalt has been found,that is when the loading is stopped the modulus of asphalt can recover slowly.So it is essential to study the fatigue characteristic of asphalt at different loading modes.The fatigue characteristic of asphalt under continuous loading mode has been studied,their fatigue characteristics were evaluated by four kinds of indexes(50%G*、DER、DR、δ) and the healing ability of asphalt has been studied.The results show that the fatigue performance of asphalt descends with the loading increasing.When the loading is bigger,the modulus decreases with the times of loading increasing,and when the loading is smaller,there is stiffness phenomenon.The indexes(50%G*、DER、DR、δ) have some deficiency in evaluating the fatigue characteristic of asphalt.The healing characteristic has an important performance on the fatigue characteristic of asphalt.The healing rate at the initial period after stopping loading is bigger than later.When the time is long enough,the modulus can recover to the initial value,but the phase angle changed.
出处
《武汉理工大学学报(交通科学与工程版)》
2011年第1期190-193,共4页
Journal of Wuhan University of Technology(Transportation Science & Engineering)
基金
国家自然科学基金项目资助(批准号:50778057)
关键词
沥青
疲劳特性
自愈性
模量
asphalt
fatigue characteristic
healing
modulus