Abstract The digital image correlation (DIC) technique was applied to the analysis of displacement fields along the surface cracks of ultra-high-performance fiber-reinforced concrete (UHPFRC) under a bending load. Analysis was performed on the fiber bridging forces acting on a unit area of cracked sections belonging to different regions (perfect bonding region, partial debonding region, and full debonding region), according to the fiber distribution characterization and DIC data. By using the DIC technique, the visualization and quantification of the UHPFRC fracture properties could be determined. The length of the uniform zone increased, whereas the fracture process decreased under the external load of the limit of proportionality (LOP). With the appearance of macro-cracks under the external load of the modulus of rupture (MOR), the length of the uniform and fracture process zones increased as the fiber content increased. However, the localization zone decreased. The steel fiber volume fractions had limited influence on the tensile strain at cracking and the complete debonding of fibers.

中文翻译：

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超高性能纤维混凝土（UHPFRC）受弯应力应变场沿裂纹发展的数字图像相关技术

摘要 将数字图像相关（DIC）技术应用于超高性能纤维混凝土（UHPFRC）在弯曲载荷作用下沿表面裂缝的位移场分析。根据纤维分布表征和DIC数据，对作用于不同区域（完美结合区、部分脱粘区和完全脱粘区）的裂纹断面单位面积上的纤维桥接力进行了分析。通过使用 DIC 技术，可以确定 UHPFRC 断裂特性的可视化和量化。在比例极限（LOP）的外部载荷作用下，均匀区长度增加，而断裂过程减少。随着断裂模量（MOR）外载荷作用下宏观裂纹的出现，均匀和断裂加工区的长度随着纤维含量的增加而增加。然而，定位区域减少了。钢纤维体积分数对开裂时的拉伸应变和纤维完全脱粘的影响有限。