Research on the fracture mechanical performance of basalt fiber nano-CaCO3 concrete based on DIC technology
Research on the fracture mechanical performance of basalt fiber nano-CaCO3 concrete based on DIC technology
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DOI：
10.1016/j.conbuildmat.2022.127193
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发表时间：
2022-03-19
影响因子：
7.4
通讯作者：
Diao, Mushuang
中科院分区：
文献类型：
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作者：
Lian, Huiheng;Sun, Xinjian;Diao, Mushuang
纳米碳酸钙混凝土（NCC）由于结构致密而具有良好的力学性能，玄武岩纤维的添加可有效改善其断裂性能。研究玄武岩纤维纳米碳酸钙混凝土（BFNCC）断裂过程中的全阶段破坏有助于解释其增韧机理。为探讨玄武岩纤维纳米CaCO3混凝土（BFNCC）的断裂性能及纤维增强机理。本研究制备了6种不同纳米CaCO3含量（0%、1.5%、2%、2.5%、3%和3.5%）的混凝土试件，养护3天、7天、14天和28天，通过拉伸和压缩力学试验探索最佳纳米CaCO3含量。基于最佳含量，进行基本力学性能测试和三点弯曲梁断裂试验，探讨4种纤维含量（0%、0.1%、0.2%、0.3%）BFNCC的断裂性能。本研究通过基本力学性能试验和三点弯曲梁断裂试验，考察了不同纤维掺量（0%、0.1%、0.2%、0.3%）玄武岩纤维纳米CaCO3混凝土（BFNCC）的断裂力学性能和纤维增强机理。研究结果表明，添加适量的玄武岩纤维可以改善纳米CaCO3混凝土的基本力学性能和断裂性能，其中BFNCC-0.2%工况效果最佳。根据断裂试验分析，玄武岩纤维的桥联效应主要在达到峰值载荷的90%之前表现出来。当载荷达到峰值载荷的70%时，玄武岩纤维对裂纹扩展的抑制作用开始增强，当载荷降低到峰值载荷的90%时，抑制裂纹扩展的效果逐渐下降。此外，应用扫描电子显微镜（SEM）技术对BFNCC的应力机制进行细观分析，结合数字图像相关（DIC）技术的结果，揭示了BFNCC的断裂力学性能和应力机制。本研究系统分析了玄武岩纤维对纳米CaCO3混凝土的增强效果，为BFNCC在水工建筑中的应用和发展提供理论依据。
Nano-CaCO3 concrete (NCC) has good mechanical properties due to its dense structure, and the addition of basalt fiber can effectively improve its fracture properties. The study of the full-stage failure of basalt fiber nano-CaCO3 concrete (BFNCC) during the fracture process is helpful to explain its toughening mechanism. In order to explore the fracture properties and fiber strengthening mechanism of basalt fiber nano-CaCO3 concrete (BFNCC). In this study, concrete specimens with 6 different nano-CaCO3 contents (0%, 1.5%, 2%, 2.5%, 3%, and 3.5%), cured for 3 days, 7 days, 14 days and 28 days, were prepared to explore the optimum nano-CaCO3 content by conducting tensile and compressive mechanical tests. Based on the optimum content, the basic mechanical performance test and three-point bending beam fracture test were carried out to explore the fracture properties of BFNCC with 4 fiber contents (0%, 0.1%, 0.2%, and 0.3%). In this study, the basic mechanical performance test and three-point bending beam fracture test were carried out to examine the fracture mechanical performance and fiber reinforcing mechanism of basalt fiber nano-CaCO3 concrete (BFNCC) with different fiber contents (0%, 0.1%, 0.2%, and 0.3%). The research results show that the addition of an appropriate amount of basalt fiber can improve the basic mechanical properties and fracture performance of nano-CaCO3 concrete, with the best effect achieved by the BFNCC-0.2% working condition. According to the fracture test analysis, the bridging effect of basalt fibers is mainly exhibited during the period before reaching 90% of the peak load. The inhibiting effect of basalt fibers on crack propagation begins to increase when the load reaches 70% of the peak load, and will gradually decline when the load is reduced to 90% of the peak load. Moreover, by applying the Scanning Electron Microscopy (SEM) technology to conduct a meso-analysis of the stress mechanism of BFNCC, combined with the results of the Digital Image Correlation (DIC) technology, the fracture mechanical properties and the stress mechanism of BFNCC were revealed. This study systematically analyzed the reinforcing effect of basalt fibers on nano-CaCO3 concrete, and provided a theoretical basis for the application and development of BFNCC in hydraulic construction.