压剪耦合条件下沥青-集料界面粘脱滑移特征行为研究

Study on bond-slip characteristic behavior of asphalt-aggregate interface under coupled compression-shear

为探求沥青与集料界面间的压剪断裂失效机制,在研发测试加载系统及分析原材料基本物性参数的基础上,通过制作沥青-集料三明治试件,开展了不同影响因素(集料粗糙度、沥青老化、环境温度及加载速率等)下沥青-集料界面的粘脱滑移特征行为研究,定量感知了沥青-集料界面的应力传荷与粘脱滑移过程,构建了沥青-集料界面的粘脱滑移本构模型.结果表明:增大粗糙度和法向应力与加快荷载速率能够提升界面抗剪能力与剪切抑制能;沥青老化在一定程度上能够提高界面抗剪强度,但降低了界面剪切抑制能;所构建的粘脱滑移本构模型能够表征沥青-集料界面在压剪耦合状态下应力变化三阶段特征.研究成果可为沥青混合料复杂力学行为的细观分析提供理论支撑,并为混合料结构参数的优化设计提供科学依据.

In order to investigate the failure mechanism of the asphalt-aggregate interface under the coupled compression-shear action, the shear tests were conducted to quantify the interface stress transfer and bond-slip process by taking into account the effects of surface roughness, asphalt binder aging, temperature, loading rate, etc. In addition, an interface bond-slip constitutive model was established in accordance to the experi- mental analysis. The results indicated that the increase of surface roughness, normal stress and loading rate could result in higher interface shear strength and shear resistance energies. Although asphalt binder aging could increase the interface shear strength, it imposed an adverse impact on the interface shear resistance en- ergy. The interface bond-slip constitutive model could represent a three-stage evolution process of the asphalt- aggregate interface shear failure. The findings would throw a light on the meso-mechanical analysis of asphalt mixtures, and provide scientific support for the optimization design of structure parameters of the mixtures.