FRP与混凝土界面粘结性能的试验研究

纤维(FRP)与混凝土的粘结性能是外贴纤维增强聚合物加固钢筋混凝土结构技术的关键问题。采用修正梁模型,对9个外贴FRP条带加固混凝土受弯构件的粘结性能进行了试验研究。分析了FRP应变、局部粘结剪应力发展规律以及沿粘结长度在各级荷载下的分布规律。考察了混凝土强度和FRP粘结长度对粘结强度等粘结性能的影响。验证了FRP有效粘结长度,探讨了有效粘结长度的影响因素,计算得到了局部粘结剪应力滑移关系曲线。通过对试验结果的统计回归分析,提出了局部粘结剪应力滑移本构关系模型以及有效粘结长度计算公式,分析结果与试验结果都吻合较好,可供实际加固改造工程应用及完善相应规范的编制参考。

Experimental study on bond behavior between FRP-concrete interface

Fibre reinforced polymer(FRP) composites are widely used for strengthening reinforced concrete(RC) structures.The bond behaviour between FRP and concrete plays a key role in maintaining composite action.This article examines the bond behaviour between FRP sheets and concrete using a modified beam test.The primary test variables are the concrete strength and bond length.The influence of bond length and concrete strength was investigated.The strain and bond stress development and distribution under every grade of loading were studied.Test results show that the maximum local bond stress is not influenced by the FRP bond length,but increases as concrete strength increasing.At the same time,the local bond stress and slip were obtained and then were used to infer the local bond stress-slip curve.Based on the experimental results,a new model representing the local bond stress versus slippage relationship was proposed.The analytical results are well coincident with the experimental results,and are valuable for compiling corresponding codes and practical engineering application.