沥青混合料单轴重复加卸载内部结构分析

Internal structure of asphalt mix with X-ray computerized tomograph under repetitive uniaxial loading

利用可同步进行CT(ComputerizedTomograph)扫描的三轴仪,进行了沥青混合料单轴重复加、卸载实验。根据CT数和CT图像分析了加、卸载过程中,沥青混合料内部结构和密度的变化。计算了不同加、卸载阶段的损伤因子和结构系数。结果表明:加载初期损伤因子略有减小,属于压密阶段;随加、卸载的进行,损伤逐渐加大,而且试件内部损伤的演化、发展与试件空隙分布密切相关。

The repetitive uniaxial loading compression tests are conducted with a new set of modified triaxial compression apparatus, which made the asphalt mixture samples can be scanned with Computerrized Tomograph (CT) during different loading process. With the test results, the internal structures of asphalt mixture sample of different stages are analyzed from CT numbers and CT images. The damage factors and structural coefficients are calculated. The test results show that the inital damage factors decrease at the beginning of loading and increase with the increasement of different loadings, and the evaluation and development of inner damage of asphalt mix sample are strongly influenced by the distribution of air voids in the sample.