基于SHRP方法的不同层位旧沥青性能试验评价

Based on SHRP method the evaluation on the performances of the used asphalt for different layers in pavement structure

针对某高速公路沥青路面不同层位的回收沥青及其短期老化(旋转薄膜烘箱RTFOT)和长期老化(旋转薄膜烘箱RTFOT+压力老化PAV)后的沥青,应用Superpave技术中的PG分级方法开展动态剪切流变(DSR)和低温弯曲梁流变(BBR)试验,分别评价它们的高温稳定性、低温抗裂性、抗疲劳性能及耐老化性能.同时,利用沥青混合料简单性能试验仪(SPT)进行不同层位沥青混合料的重复加载永久变形试验,评价它们的高温稳定性能.研究结果表明,不同层位面层的旧沥青由于沥青品种、老化程度不同,所测试出的高温稳定性、低温抗裂性、抗疲劳性能及耐老化性能都有所差异.高温稳定性增强了,但低温抗裂性、抗疲劳性能及耐老化性能均有所降低,需进一步提高.还确定了不同层位沥青的最高和最低的路面设计温度等级.

The PG classification method of Superpave technology is used to carry out the dynamic shear rheometer（DSR） and low-temperature bending beam rheometer（BBR）tests for recycled asphalt of the different layers in the asphalt pavement and its short-term aging（RTFOT） and long-term aging（RTFOT ＋ PAV） asphalt in expressway,their high temperature stability,low temperature cracking resistance,fatigue performance and anti-aging properties are evaluated respectively.Meanwhile,repeated load permanent deformation test of asphalt mixture in the different layers is carried out by the use of the asphalt mixture Simple Performance Tester（SPT）,and their high temperature stability is evaluated.The analysis results show that due to the different bituminous variety and aging,old asphalt in surface of the different layers of which the high temperature stability,low temperature cracking resistance,fatigue performance and anti-aging properties are different.High temperature stability is enhanced,but the low temperature cracking resistance,anti-fatigue properties and aging resistance are reduced to be further improved.And the highest and lowest grade of the pavement design temperature is determined on asphalt in the different layers.