关键词: 碳纤维片材加固混凝土梁, 四点弯曲, 剪滞分析, 裂缝密度, 最大裂桂宽度

Abstract:

With the aid of the analytical methods of composite mechanics , a layered shear-lag model is established to investigate the multiple cracking of reinforced concrete (RC) beam reinforced with carbon fiber sheets under four-point bending. The relationships between the crack items and the applied load as well as the number of carbon fiber sheets are then obtained , where the crack items include the crack density and the maximum crack width in the reinforcement cover under the pure bending part of the beam. The calculated results are in good agreement with the xisting experimental ones , showing that (1) the crack density and width increase with the applied load; (2) with the increase of the number of carbon fiber sheets , the crack spacing obviously becomes small , while the maximum crack width almost remains constant; and (3) in the case of a small number of carbon fiber sheets , a cluster of sa-turation cracks emerge in the reinforcement cover under the pure bending part of the beam when the applied load reaches or exceeds a certain value.

Key words: carbon fiber sheet-reinforced concrete beam, four-point bending, shear-lag analysis, crack density, maximum crack width