中文摘要：

为了明确中间主应力对沥青混合料强度的影响,利用自主开发的能实现三向独立加载的简易真三轴试验设备,对3种沥青混合料开展了-10℃下的三向压缩强度试验,包括不同温度和加载速率下的强度试验,中间主应力在最大主应力和最小主应力之间变化时的强度试验,以及2个方向压力相等条件下的强度试验。结果表明：随着侧压的增加,沥青混合料的强度包络线逐渐弯曲;当中间主应力从最大主应力逐渐变化到最小主应力时,沥青混合料的破坏强度先增加后减小;同一π平面上的强度试验点离摩尔-库伦准则轮廓线较远,离双剪强度理论轮廓线较近;中间主应力对沥青混合料的强度有显著影响,建议采用能够反映中间主应力影响的强度理论来表征沥青混合料的破坏准则。

英文摘要：

In order to find out the effect of intermediate principle stress on asphalt mixture strength,three-direction compression strength tests were carried out on three kinds of asphalt mixtures at-10 ℃ with self-developed simplified true triaxial test machine.The tests were carried out under various conditions,including different temperatures and different loading speeds,with intermediate principle stress changing from maximum principle stress to minimum principle stress and with compressions from two directions being the same.The results indicate that asphalt mixture strength envelop curve bends gradually with lateral compression increasing.Asphalt mixture failure strength first increases then decreases with intermediate principle stress decreasing from maximum principle stress to minimum principle stress.The tested strength points on aπplane are far away from Mohr-Coulomb standard contour curve,but they are close to twin shear strength theory contour curve.Intermediate principle stress has apparent effect on asphalt mixture strength.So,the strength theory which can reflect the effect of intermediate principle stress is suggested to be adopted to characterize asphalt mixture failure criteria.