沥青混合料离析防治及路面压实技术研究——以兰州绕城高速公路为例

Research on Asphalt Mixture Segregation Prevention and Control and Pavement Compaction Technology--Taking Lanzhou Ring Expressway as an Example

针对高速公路的路面离析问题,结合兰州绕城高速公路南绕城路段的施工经验和养护记录,对离析现象的种类和成因进行研究,提出防治沥青混合料离析的措施,研究影响路面压实的相关因素,提升北绕城路段的路面施工质量。研究表明,不同类型的沥青混合料中,沥青玛蹄脂碎石混合料(SMA)最易压实,但是运营阶段抵抗变形能力较弱;不同级配的沥青混合料,中值级配压实最容易,但上限级配在运营阶段的抵抗变形能力最强;随着改性剂掺量的增加,压实难度逐渐降低,但施工阶段所需要的能量逐渐增大;沥青混合料在145℃时,碾压成型较为容易,压实度较好。综上所述,后续北绕城高速路的施工,推荐采用掺量为3.5%~4.5%的中值级配的AC改性沥青混合料,在145℃时碾压成型。

In response to the problem of pavement segregation on highways,combined with the construction experience and maintenance records of the southern ring section of Lanzhou Ring Expressway,the types and causes of segregation phenomenon are studied,measures to prevent and control asphalt mixture segregation are proposed,and relevant factors affecting pavement compaction are studied to improve the quality of pavement construction on the northern ring section.Research has shown that among different types of asphalt mixtures,asphalt mastic macadam mixture(SMA)is the easiest to compact,but its resistance to deformation is weak during operation;for asphalt mixtures with different gradations,the median gradation is the easiest to compact,but the upper limit gradation has the strongest resistance to deformation during the operation stage;as the amount of modifier increases,the difficulty of compaction gradually decreases,but the energy required during the construction phase gradually increases;when the asphalt mixture is rolled at 145℃,it is easier to form and has a good degree of compaction.In summary,for the subsequent construction of the north Ring Expressway,it is recommended to use AC modified asphalt mixture with a median grading of 3.5%to 4.5%,which is rolled and formed at 145℃.