基于疲劳性能的应力吸收层混合料设计指标
发布时间：2018-11-23 09:03
【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1 500×10~(-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1 500×10~(-6)应变下的疲劳寿命为302 023次,因此以1 500×10~(-6)应变下疲劳寿命≥3×10~6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1 77℃黏度维持在3.4~3.6 Pa·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、1 35℃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≤5.1 mm,SBS改性沥青软化点≥93℃,SBS改性沥青135℃黏度≥1.95 Pa·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.
[Abstract]:Rubber asphalt was prepared by mixing matrix asphalt with rubber powder, SBS modified asphalt was prepared by mixing matrix asphalt with SBS modifier, and rubber asphalt stress absorption layer mixture and SBS modified asphalt stress absorption layer mixture were designed by corresponding gradation. In this paper, the common Strata stress absorbing layer mixture is selected as the contrast material, and the fatigue test of these three modified asphalt mixtures under 1 500 脳 10 ~ (-6) strain is carried out through a large number of four-point bending trabecular fatigue tests (15 鈩，
本文编号：2350997
[Abstract]:Rubber asphalt was prepared by mixing matrix asphalt with rubber powder, SBS modified asphalt was prepared by mixing matrix asphalt with SBS modifier, and rubber asphalt stress absorption layer mixture and SBS modified asphalt stress absorption layer mixture were designed by corresponding gradation. In this paper, the common Strata stress absorbing layer mixture is selected as the contrast material, and the fatigue test of these three modified asphalt mixtures under 1 500 脳 10 ~ (-6) strain is carried out through a large number of four-point bending trabecular fatigue tests (15 鈩，
本文编号：2350997
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