大粒径透水性沥青混合料抗剪强度试验研究

Experimental Research on Shear Strength of LSPM

摘要: 大粒径透水性沥青混合料由于具有优良的高温稳定性、透水性，对于解决半刚性基层路面的水损害及反射裂缝起到了很好的作用，目前在国内形成了独具特色的山东路面结构形式。其设计标准已被国际公认为达到了长寿命沥青路面设计标准。沥青混合料的强度和稳定性理论要求沥青混合料在高温时必须具有良好的抗剪切强度以抵抗荷载的作用，而抗剪强度的高低主要由沥青混合料的黏聚力C和内摩擦角φ两个参数决定。沥青混合料的黏聚力C取决于沥青的性能及沥青与矿料的相互作用，而内摩擦角φ的大小由沥青混合料的矿料级配、颗粒形状、表面特征及沥青膜厚度决定。基于LSPM的上述性能特点，本文在采用不同胶结料进行LSPM混合料设计的基础上对设计混合料的抗剪切强度进行了研究分析。抗剪强度结果表明，胶粉的加入提高了沥青胶结料的黏韧性，将其用于LSPM混合料时，抗剪切强度相比采用MAC和SBS改性沥青好，道路石油沥青由于其黏度较低，设计混合料的抗剪强度同比最小。MAC和SBS改性沥青较基质沥青具有明显的高温性能优势，橡胶沥青作为高粘弹、低成本产品，用于大粒径透水性沥青混合料具有良好的高温性能，具有良好的应用前景。

Abstract: Due to its excellent high temperature stability and water permeability, LSPM has played a very good role in solving the water damage and reflective cracks of the semi-rigid base pavement. At present, a unique Shandong pavement structure has been formed in China. Its design standard has been recognized internationally as reaching the design standard for long-life asphalt pavement. According to the theory of asphalt mixture strength and stability, asphalt mixture must have cer-tain shear strength at high temperature. The shear strength mainly depends on the two parameters of asphalt mixture’s cohesion C and internal friction angle φ. The cohesive force C of the asphalt mixture depends on the performance of the asphalt and the interaction between the asphalt and the mineral material, while the internal friction angle φ depends on the mineral material gradation, particle shape, surface characteristics and thickness of the asphalt film of the asphalt mixture. Based on the above-mentioned performance characteristics of LSPM, this paper uses different binders to design LSPM mixtures, and analyzes the shear strength of LSPM mixtures with different binder designs. According to the research results, since the rubber asphalt has a higher viscosity, the shear strength of the mixture designed with it is better than that of MAC and SBS. Unmodified asphalt has lower viscosity. The shear strength of the design mixture is the smallest compared with others. MAC and SBS modified asphalt has obvious advantages in high temperature performance compared with unmodified asphalt. As a high viscoelastic, low-cost product, rubber asphalt has good high temperature performance when used in LSPM and has good application prospects.