| 摘要: |
| 以基质沥青与胶粉搅拌制备橡胶沥青，以基质沥青与SBS改性剂搅拌制备SBS改性沥青，然后分别采用相应的级配设计橡胶沥青应力吸收层混合料和SBS改性沥青应力吸收层混合料.选取目前常见的Strata应力吸收层混合料为对比材料，通过大量四点弯曲小梁疲劳试验（15℃）对这3种改性沥青混合料进行1500×10-6应变下的疲劳试验，分析混合料疲劳寿命与胶粉掺量(质量分数)、SBS改性剂掺量(质量分数)及改性沥青针入度、软化点、黏度的关系.结果表明：Strata应力吸收层混合料在1500×10-6应变下的疲劳寿命为302023次，因此以1500×10-6应变下疲劳寿命≥3×106次作为应力吸收层混合料的设计指标.橡胶沥青应力吸收层混合料疲劳寿命与胶粉掺量和橡胶沥青177℃黏度具有很好的相关性，按设计指标进行橡胶沥青应力吸收层混合料设计时，要求胶粉掺量为19.6%～20.5%，橡胶沥青177℃黏度维持在3.4～3.6Pa·s.SBS改性沥青应力吸收层混合料疲劳寿命与SBS改性剂掺量和SBS改性沥青针入度、软化点、135℃黏度具有很好的线性相关性，按设计指标进行SBS改性沥青应力吸收层混合料设计时，若A型、B型SBS改性剂混合使用，则要求SBS改性剂掺量≥6.5%，SBS改性沥青针入度≤5.1mm，SBS改性沥青软化点≥93℃，SBS改性沥青135℃黏度≥1.95Pa·s；适当加大油石比和调整级配中关键筛孔通过率可增大SBS改性沥青应力吸收层混合料疲劳寿命；B型SBS改性剂更适合用在SBS改性沥青应力吸收层混合料设计中. |
| 关键词: 应力吸收层 疲劳性能 混合料设计 指标 |
| DOI：103969/j.issn1007 9629201401030 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(50308021) |
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| Index for Designing Stress Absorbing Layer Mixture Basedon Fatigue Performance |
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HUANG Ming1, HUANG Weidong2, LI Benliang2, LI Yanwei3
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1.Shanghai Municipal Engineering Design InstituteGroup Co., Ltd., Shanghai 200092, China;2.Key Laboratory of Road and Traffic Engineering of Ministry of Education, Tongji University, Shanghai 201804, China;3.Transportation Bureau of Shijiazhuang City, Hebei Province, Shijiazhuang 050051, China
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| Abstract: |
| Rubber asphalt and SBS modified asphalt were prepared in routine way and stress absorbing layer mixtures were designed with suitable gradations. At the same time, Strata stress absorbing layer was regarded as contrast material. Through a large number of four point bending beam fatigue test(at 15℃) performed on these three asphalt mixtures with strain of 1500×10-6, relationships between fatigue life of the mixtures and crumb rubber content(by mass), SBS modifier content(by mass) and penetration, softening point and viscosity of modified asphalt were investigated. The results show that the Strata stress absorbing layer mixtures fatigue life is 302023, so the fatigue life of greater than 3×106 times under strain of 1500×10-6is taken as a judgment standard of fatigue life. The fatigue life of rubber asphalt stress absorbing layer mixture has a relatively good correlation with crumb rubber content and viscosity of rubber asphalt at 177℃, crumb rubber content is required ranging at 19.6%20.5%, 177℃ viscosity is required to be 3.43.6Pa·s. Fatigue life of SBS modified asphalt stress absorbing layer mixture has a good linear correlation with SBS modifier content and penetration, softening point, 135℃ viscosity of SBS modified asphalt. If SBS modifier type A and B are mixed together, SBS modifier content≥6.5%, penetration≤5.1mm, softening point≥93℃, 135℃ viscosity≥1.95Pa·s are required. It is also found that fatigue life can be increased by increasing the oil aggregate ratio and adjusting key sieve passing rate in the gradation appropriately, and that type B SBS modifier is more suitable for stress absorbing layer mixture design. |
| Key words: stress absorbing layer fatigue performance mixture design index |
