玄武岩纤维混凝土抗压强度分析与微观表征

采用现场试验、电镜扫描（SEM）及数值模拟相结合的方法来研究玄武岩纤维对混凝土抗压强度的影响机制。通过混凝土抗压试验探究不同龄期下纤维掺量和纤维长度对混凝土抗压强度的影响，及采用电镜扫描对玄武岩纤维混凝土（BFRC）的微观结构进行机理分析。在细观尺度上采用Mori-Tanaka均化算法和连续介质渐进损伤理论建立混凝土损伤力学模型，研究不同纤维掺量和纤维长度的耦合作用对混凝土抗压强度的影响，并将试验和数值模拟结果进行对比与分析，验证其模型的可行性。结果表明：玄武岩纤维的掺入能够改善混凝土的抗压性能，纤维长度为6 mm的效果较佳；通过电镜扫描发现，纤维的“抱团”现象和纤维–界面之间的薄弱层不利于混凝土抗压强度的提升，但纤维的阻裂效应使得混凝土整体结构的抗压强度有所增加；试验与数值模拟结果具有良好的一致性。

Compressive strength analysis and microscopic characterization of basalt fiber reinforced concrete

This paper reports a study on basalt fiber reinforced concrete (BFRC) combining field test, scanning electron microscope (SEM), and numerical simulation, focusing on the mechanism of basalt fiber influencing concrete compressive strength. The influence of fiber content and fiber length is experimentally observed by conducting compressive tests on samples at different ages, and its SEM data are used to analyze the microstructure. We develop a mechanics model of concrete damage at the microscopic level based on the Mori-Tanaka algorithm and the progressive damage theory of continuous medium, and use it to examine the coupling effect of different fiber contents and different fiber lengths on the compressive strength. To verify its feasibility, the simulation results are compared with our experimental measurements and both agree well. The results show that adding basalt fiber to concrete improves compressive strength and the fiber length of 6mm is better. SEM images show that the phenomenon of fiber adhering and the weak layer between the fiber and the interface have an adverse effect on compressive strength, but the resistance of fiber against cracking leads to a considerable increase in compressive strength.