| 摘要: |
| 采用动态剪切流变仪（DSR），在应力控制模式下对沥青进行重复剪切疲劳试验.根据加载过程中沥青复数剪切模量变化率曲线拐点所对应的加载次数定义了一种新的沥青疲劳寿命（NfG*）.对NfG*，Nf50（复数剪切模量降低至50%时对应的剪切次数）和基于耗散能分析方法确定的疲劳寿命指标（N1，Np20和Nfm）的一致性、区分度以及相关性进行研究.结果表明：在不同测试条件下，由沥青的不同疲劳评价指标所得到的疲劳寿命存在一致性排序，即NfG*>Nf50>Np20>N1，Nfm与NfG*接近；Nfm对沥青疲劳性能的区分度最大，NfG*次之，N1最小；NfG*与Nfm呈现良好线性关系，且斜率接近1.NfG*可作为一种简单、有效的沥青疲劳性能评价指标. |
| 关键词: 沥青 疲劳寿命 耗散能 评价指标 |
| DOI：103969/jissn1007 9629201502028 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51378393） |
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| Evaluation Method for Fatigue Life of Asphalt Based on Dynamic Shear Rheometer Test |
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SUN Daquan, LIN Tianban, CAO Linhui
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Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University, Shanghai 201804, China
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| Abstract: |
| A repeated shear fatigue test using a dynamic shear rheometer（DSR） was conducted with a controlled stress loading mode. An asphalt fatigue life criteria（NfG*） was defined as the loading cycle at inflection point of the shear modulus change ratio curve in the fatigue test. The consistency, distinction degree and correlation of five fatigue criteria including NfG*, Nf50 （the loading cycle at 50% loss in modulus from the initial value） and energy based fatigue failure criteria（N1, Np20, Nfm） were studied. The test results show that the fatigue life evaluated with different indicators has a consistency order：NfG*>Nf50>Np20>N1, while the value of Nfm is similar to NfG*； Nfm has the highest distinction, NfG* take the second place and N1 is the least; NfG* has a strong correlation with Nfm, and the slope approximates to one. Finally, NfG* is recommended as a simple and effective fatigue indicator of asphalt binder. |
| Key words: asphalt fatigue life dissipated energy evaluation indicator |
