低标号沥青在福建省沥青路面中的应用

Application of Low-grade Asphalt in Asphalt Pavement in Fujian Province

为验证低标号硬质沥青在福建省的适用性,对以30#基质沥青为代表的低标号硬质沥青的高温稳定性进行研究。利用APA(Asphalt Pavement Analyzer)车辙试验,对30#低标号沥青混合料,在福建省高速公路上面层与中面层广泛应用的SBS I-D改性沥青混合料,以及最为常见的70#基质沥青混合料的高温稳定性进行对比。为验证APA车辙试验结果的有效性,进行了缩尺加速加载MMLS试验,对3种沥青混合料高温稳定性进行评价与验证。考虑到福建省夏季高温的气候特征,除了规范的标准高温(60℃)试验条件外,还进行了极端高温(70℃)试验条件下的性能评价。APA车辙试验结果表明30#硬质沥青在两种温度条件(60℃,70℃)下的抗车辙能力与SBS I-D改性沥青基本相同。这表明在冬季气候温和的中国南方地区,低温性能相对较差但更加廉价的低标号硬质沥青能够替代SBS改性沥青,应用于抗车辙性能要求较高的沥青路面。缩尺加速加载MMLS试验结果在对30#硬质沥青与SBS I-D改性沥青的高温性能评价方面与APA车辙试验结果保持一致。但对于70#基质沥青的高温稳定性评价,MMLS试验与APA车辙试验的结果有较大差异,表明“钢轮、薄板”的车辙试验对于抗车撤性能较差混合料的评价与实际路面条件下的结果存在差异。

In order to verify the applicability of low-grade hard asphalt in Fujian Province,the high temperature stability of low-grade hard asphalt represented by base asphalt No.30 is studied.The high temperature stability of low-grade asphalt mixture No.30,SBS I-D modified asphalt mixture widely used in the upper and middle layers of Expressway in Fujian Province,and the most common base asphalt mixture No.70 are compared by APA rutting test.To verify the effectiveness of the APA rutting test result,the scale accelerated loading MMLS test is carried out to evaluate and verify the high temperature stability of 3 asphalt mixtures.Considering the climate characteristics of high temperature in summer in Fujian Province,the tests are not only conducted under the standard temperature condition(60℃),but also conducted under the extreme high temperature condition(70℃).The APA rutting test result shows that the rutting resistance of hard asphalt No.30 is basically the same as that of SBS I-D modified asphalt under 2 temperature conditions(60℃,70℃),showing that the low-temperature performance is relatively poor,but the cheaper low-grade hard asphalt can replace the SBS modified asphalt and can be used in the asphalt pavement with higher anti rutting performance requirements in the southern China where the climate is mild in winter.The scale accelerated loading MMLS test result is consistent with that of APA rutting test result in high temperature performance evaluation of hard asphalt No.30 and SBS I-D modified asphalt,but the deviation between the APA test and the MMLS test appears in the evaluation of asphalt mixture No.70,showing that the rutting test of“steel wheel,thin plate”for evaluating the mixture with poor anti rolling performance is different from the actual pavement condition.