不同受力模式下沥青混合料强度的速度特性试验研究

为了了解不同加载速率对沥青混合料强度参数的影响以及不同受力模式下沥青混合料的破坏原因,对不同加载速率下单轴压缩、弯曲、直接拉伸和劈裂强度进行试验研究,并从沥青混合料结构组成对不同受力模式下强度差异进行解释.研究结果表明:加载速率对沥青混合料强度有显著影响,强度与加载速率呈近似幂函数关系；沥青混合料黏聚力c随加载速率增大先急剧增大而后趋于平稳,内摩擦角(φ)随加载速率变化规律正好与黏聚力规律相反,先急剧减小而后趋于平稳；在相同应变率条件下,沥青混合料的强度受加载方式的影响,不同受力模式下的强度由大至小依次为抗压强度、弯拉强度、直接拉伸强度和劈裂强度,试验结果为建立沥青混合料强度理论与破坏准则奠定了基础.

Strength experiment of speed characteristic of asphalt mixtures in different force modes

In order to understand the influence of different loading rates on strength parameters of asphalt mixtures,and how different force modes caused the destruction of asphalt,uniaxial compression,bending,direct tension and splitting strength tests in different loading rates were studied.And strength variations of asphalt mixtures in different force modes were explained from structure composition.The results show that the effect of loading speed on strength of asphalt mixtures is significant,and their relationship curve can be fitted by power function.Internal cohesion of asphalt mixtures increase rapidly and then stabilizes with the increase of loading rate,internal friction angle variation with the loading rate coincides with the laws of cohesion contrary,which decreases firstly sharply and then stabilizes.In the same strain rate conditions,the influence of force mode on the strength of asphalt mixtures from large to small is compressive strength,bending strength,direct tensile strength and splitting strength.The results lay the foundation for the establishment of strength theory and failure criteria of the asphalt mixture.