| 摘要: |
| 以G·sin δ为代表指标的沥青胶结料疲劳性能评价方法高度依赖动态剪切流变仪,针对该方法所需设备在中国普及率较低且对SBS改性沥青的适用性较差等问题,采用测力延度仪进行双边缺口拉伸试验,提出了以临界裂纹尖端位移（CTOD）作为沥青胶结料常温条件下（0～30℃）抗疲劳性能的评价指标.用CTOD和G·sin δ这2个指标对7个沥青胶结料的抗疲劳性能进行排序,并采用四点弯曲疲劳试验从混合料层面对沥青胶结料的抗疲劳性能的排序结果进行验证,最后用显著性检验方法比较了温度对CTOD区分度的影响.结果表明：CTOD与G·sin δ对SBS改性沥青的疲劳性能评价存在分歧,四点弯曲疲劳试验得到的混合料疲劳性能与CTOD所表征的沥青胶结料结果更具相关性;显著性检验发现,与15℃相比,25℃的CTOD指标对选用沥青胶结料的区分度更好.CTOD所需试验设备在中国应用较广,有望成为沥青胶结料抗疲劳性能的有效鉴定方法之一. |
| 关键词: 沥青胶结料 疲劳性能 临界裂级尖端位移 双边缺口拉伸试验 |
| DOI：103969/j.issn.1007 9629202004033 |
| 分类号: |
| 基金项目:国家自然科学基金面上资助项目（51778541）；中央高校基本科研业务费专项资金资助项目（2682019ZT05）；四川雅康高速科研攻关项目 |
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| Fatigue Performance Evaluation of Asphalt Binder Based on Critical CrackTip Opening Displacement |
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LUO Haoyuan, OUYANG Chengfei, LENG Huikang, DING Haibo, QIU Yanjun
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School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China
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| Abstract: |
| At present, G·sin δ is a representative of asphalt binder fatigue resistance test, which is highly dependent on dynamic shear rheometer. The equipment required for this method is not popular in China and of poor applicability to SBS modified asphalt. To solve the above problems, the double notch tensile test of the force measuring device was introduced, and the critical crack tip opening displacement(CTOD) was proposed as the anti fatigue performance evaluation index of the asphalt binder under ordinary temperature conditions(030℃). Using CTOD and G·sin δ to rank the fatigue resistance of 7 asphalt binders, and the four point bending beam fatigue performance test was used to verify the ranking result from the mixture level. Finally, the significance test was used to compare the effects of temperature on CTOD discrimination. The results show that CTOD and G·sin δ have different fatigue performance evaluations for SBS modified asphalt, but the four point bending beam fatigue test shows that the conclusion of CTOD is more correlated with the fatigue performance of the mixture. Significance test shows that the CTOD index at 25℃ is better than that at 15℃ in distinguishing asphalt binders. CTOD test equipment is widely used in China, and it is expected to become one of the effective methods to identify the fatigue resistance of asphalt cement. |
| Key words: asphalt binder fatigue performance critical crack tip opening displacement double notch tensile test |
