基于声发射技术的钢纤维混凝土损伤特性研究

Damage Characteristics of Steel Fiber Concrete Based on Acoustic Emission Technology

摘要: 煤矿大直径井筒施工，面对深厚冲积层的复杂环境，许多新型矿井正尝试应用高强钢纤维混凝土作为井壁材料。为探讨钢纤维混凝土的损伤特性，基于声发射技术并结合损伤力学理论，开展钢纤维混凝土材料力学特性分析，结果表明：1) 随着钢纤维掺量的增加，钢纤维混凝土的抗压强度、延性、韧性得到明显的改善，破坏类型由受拉破坏转变为剪切破坏。2) 基于声发射参数定义的损伤参量模型，可定量分析单轴和三轴加载条件下钢纤维混凝土在整个加载过程中的损伤特性。3) 拟合后的声发射速率参数a与损伤程度具有很好的相关性；对钢纤维混凝土破坏有预警作用。

Abstract: Facing the complex environment of deep alluvium, many new coal mines are trying to use high strength steel fiber reinforced concrete (SFRC) as shaft lining material. In order to investigate the damage characteristics of steel fiber reinforced concrete (SFRC), based on acoustic emission technology and damage mechanics theory, the mechanical properties of SFRC were analyzed. The results show that: 1) With the increase of steel fiber content, the compressive strength, ductility and toughness of steel fiber reinforced concrete are obviously improved, and the failure type changes from tensile failure to shear failure. 2) Based on the damage parameter model defined by acoustic emission parameters, the damage characteristics of SFRC under uniaxial and triaxial loading can be quantitatively analyzed. 3) The acoustic emission rate parameter a has a good correlation with the damage degree, and has an early warning effect on the damage of steel fiber reinforced concrete.