This study aims to evaluate the macro-micro-meso-mechanical properties of basalt fiber (BF)-reinforced recycled aggregate concrete (BFRAC). Firstly, the effects of BF with different contents and lengths on the mechanical properties of recycled aggregate concrete (RAC) at different ages were analyzed. In addition, the distribution of BF, bond between BF and matrix, failure form of BF, and element composition of the fiber interface transition zone were analyzed using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Finally, the numerical simulation of cubic compression and splitting tensile tests of RAC specimens were carried out, and the stress–strain curve and failure morphology of RAC under static loading was studied. The results show that BF content is the main factor affecting the mechanical properties of concrete within the range of test fiber content (0.1%–0.3%), and the optimal content of BF is 0.2%. The length of BF has little effect on the compressive properties of RAC, but the increase of BF length can improve the splitting tensile and flexural properties of RAC. Through SEM-EDS, the toughening and cracking resistance mechanisms of the BF are obtained. In the meso-simulation, the numerical simulation results are in high agreement with the experimental phenomenon, and this method provides an effective technical method for the prediction and establishment of RAC failure model. In summary, the research results can be used as reference for the establishment of the RAC mechanical model, performance research, and practical engineering application in the future.

本研究旨在评估玄武岩纤维（BF）-增强再生骨料混凝土（BFRAC）的宏观-微观-细观力学性能。首先，分析了不同掺量和长度的BF对不同龄期再生骨料混凝土（RAC）力学性能的影响。此外，采用扫描电子显微镜（SEM）和能量色散X射线光谱仪（EDS）分析了BF的分布、BF与基体的结合、BF的失效形式以及纤维界面过渡区的元素组成。最后，进行立方压缩和劈裂拉伸试验的数值模拟。对RAC试件进行了研究，研究了RAC在静载荷作用下的应力-应变曲线和破坏形态。结果表明，在试验纤维含量范围内（0.1%~0.3%），BF含量是影响混凝土力学性能的主要因素，BF的最佳含量为0.2%。BF的长度对RAC的抗压性能影响不大，但BF长度的增加可以改善RAC的劈裂拉伸和弯曲性能。通过SEM-EDS，增韧和得到了高炉的抗开裂机理。在细观模拟中，数值模拟结果与实验现象高度吻合，该方法为RAC失效模型的预测和建立提供了有效的技术方法。综上所述，该研究成果可为RAC力学模型的建立、性能研究和未来的实际工程应用提供参考。