FRP与混凝土界面黏结-滑移本构关系的试验研究

Experimental study on bond-slip behavior between FRP and concrete

FRP与混凝土的黏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黏结性能进行了试验研究,考察混凝土强度和FRP黏结长度对黏结性能的影响,分析了FRP应变以及局部黏结剪应力发展规律以及沿黏结长度在各级荷载下的分布规律,计算得到了局部黏结剪应力-滑移关系曲线。通过对试验结果的统计回归分析,提出3种不同复杂程度的局部黏结剪应力-滑移本构关系模型,3种本构关系模型与试验结果都吻合较好,可供实际加固改造工程应用以及完善相应规范的编制参考。

FRP laminates, because of their superior properties, are being successfully used for the strengthening of existing reinforced concrete structures. Critical to strengthening a concrete structure through externally bonded FRP plates is the bond behavior between FRP and concrete. A modified beam test specimen was employed to study the bond behavior and the force transfer of the composite material plates adhered to concrete. The influences of the bond length, and concrete strength on the bond behavior was investigated, the strain development and distribution in GFRP sheet along the bond length was obtained, and the direct shear bond stress distribution and local bond stress versus slippage relationship were analyzed. Based on the test results, three local bond stress-slip constitutive models were proposed. These models matches the experimental results well, and are valuable references for the corresponding codes and engineering applications.