设计15个外贴碳纤维增强复合材料(CFRP)的Z型试件进行直剪加载试验,试验参数包括直剪面钢筋配筋率(0.46%~1.2%)和CFRP加固率(0%~0.3%)。依据试验结果提出加固后钢筋混凝土直剪承载力预测表达式,并基于分量模型分析其加固机理。研究结果表明:直剪承载力随CFRP加固率增大而提高,提高幅度为6%~50%;相同CFRP加固率时,直剪承载力提高幅度随配筋率的增加而降低,承载力提高源于CFRP提供了附加的侧向夹紧力;当外贴CFRP和内埋直剪钢筋提供相等的侧向夹紧力时,两者对直剪承载力的贡献作用相近;所提出的承载力预测表达式具有较好的适用性。
Total fifteen typical Z-type specimens strengthened with external carbon fiber reinforced polymer(CFRP)strips were tested to investigate their shear transfer capacities.Test parameters included reinforcing steel bar ratios(0.46%-1.2%)and CFRP reinforcement ratios(0%-0.3%).Expressions were proposed to predict the shear transfer capacities of CFRP strengthened concrete. The reinforcement mechanism of shear transfer was analyzed based on component model.The study results show that the shear transfer capacities improve in a range of6%-50% with the increasing of CFRP reinforcement ratios. Moreover,for a given CFRP reinforcement ratio,the percentage of improvement decreases with the increasing of reinforcing steel bar ratios.The capacity improvement is believed due to the clapping force from CFRP.An approximate strengthening effect is realized when the external CFRP and the internal reinforcements provide identical clapping force in lateral direction.The proposed expressions to predict the shear transfer capacities have good applicability.