The internal micro-structure of glass and carbon fibre-reinforced polymer (FRP) rebars subjected to tensile loading was investigated using micro computed tomography (μCT) and scanning electron microscopy (SEM) images. Three dimensional (3D) and two dimensional (2D) reconstructed μCT images were used to study and quantify the void volume and its distribution along with FRP rebar samples after being subjected to tensile loads. The void volume was observed to increase in all samples as the tensile load on the samples was increased. Acoustic emission (AE) monitoring during the tensile loading was also employed to establish a correlation between the AE parameters and damage evolution in the FRP samples. Cumulative energy of AE signal in frequency domain was used to monitor the progression of the internal damage in the FRP reinforcing rebars. A high correlation was observed between the void volume measured by μCT and SEM and the cumulative energy of the AE signal.

中文翻译：

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使用显微计算机断层扫描 (μCT)、扫描电子显微镜 (SEM) 和声发射 (AE) 技术对 GFRP 和 CFRP 钢筋进行微观结构分析的比较

使用显微计算机断层扫描 (μCT) 和扫描电子显微镜 (SEM) 图像研究了承受拉伸载荷的玻璃纤维和碳纤维增强聚合物 (FRP) 钢筋的内部微观结构。三维 (3D) 和二维 (2D) 重建 μCT 图像用于研究和量化 FRP 钢筋样品在承受拉伸载荷后的空隙体积及其分布。观察到随着样品上的拉伸负载的增加，所有样品中的空隙体积增加。拉伸加载过程中的声发射 (AE) 监测也用于建立 AE 参数与 FRP 样品损伤演变之间的相关性。频域AE信号的累积能量用于监测FRP钢筋内部损伤的进展。通过 μCT 和 SEM 测量的空隙体积与 AE 信号的累积能量之间观察到高度相关性。