水工玄武岩纤维增强混凝土多尺度破坏力学特性与机理分析研究

水工混凝土结构中微裂纹成核与扩展会造成混凝土材料的抗渗、抗冻和强度等耐久性能急剧降低，进而影响水工混凝土结构的安全稳定。为改善混凝土的抗裂性能，通过掺加纤维来提升混凝土的断裂韧度和阻碍裂纹的失稳扩展是一种行之有效的方式。鉴于此，开展玄武岩纤维增强混凝土多尺度破坏力学特性与机理研究具有十分重要的理论意义和工程应用价值。项目拟开展以下主要研究：通过开展玄武岩纤维的微细观分析和宏观力学试验，建立宏观破坏力学性能与微、细观特征间的映射关系；然后，采用非线性多尺度建模方法，建立考虑玄武岩纤维混凝土细观特性的三维模型，并赋予相关力学参数，生成细观伤力学模型；最终提出可以描述玄武岩纤维混凝土增韧机理的模型以及混凝土多尺度破坏行为的数值仿真分析方法。本项目的研究将为水利工程建设和混凝土材料增强提供理论依据和技术参考。

The nucleation and propagation of microcracks in hydraulic concrete structures can lead to the drastic reduction of the durability of concrete, such as impermeability, frost resistance and strength, which will affect the safety and stability of hydraulic concrete structures. In order to improve the crack resistance of concrete, an effective manner to improve the fracture toughness of concrete is by adding fibers and preventing the unstable propagation of cracks. In view of this, it is of great theoretical significance and engineering application value to study the multi-scale failure mechanics characteristics and mechanisms of basalt fiber reinforced concrete. The following research objectives are planned to be carried out: the mapping relationship between macroscopic failure mechanisms and micro-and-mesoscopic characteristics of basalt fibers will be established through macroscopic mechanical experiment and micro-and-mesoscopic analysis. Secondly, a three-dimensional model considering the meso-characteristics of basalt fiber reinforced concrete will be established by applying non-linear multi-scale modeling method, and the relevant mechanical parameters will be given to generate the meso-damage mechanics model. Finally, a model describing the toughening mechanisms of basalt fiber reinforced concrete and a numerical simulation analysis method for multi-scale failure behavior of concrete will be proposed. This research will provide theoretical basis and technical support for the construction of water conservancy engineering projects and the reinforcement of concrete materials.