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摘要: 为了确定碳纤维加固混凝土结构承载过程中胶层部位的剪应力分布规律, 判别碳纤维与混凝土界面间是否发生剥离破坏, 进行了碳纤维布加固混凝土构件的拉伸试验, 基于弹性理论, 推导了已知力作用下的任意点胶层界面剪应力与碳纤维正应力的计算方法。计算结果表明碳纤维与混凝土界面的剪应力、正应变的分布规律与试验结果相吻合, 计算方法有较高的精度, 计算得出胶层部位的极限剪切强度为3.96 MPa, 在实际工程中, 为防止剥离破坏的发生, 应确保胶层剪切应力小于此值。Abstract: In order to study the shear stress distribution law of adhesive layer and determine the debonding failure on CFRP (carbon fibre reinforced plastic) and concrete interface in concrete strengthened structure with CFRP, a tensile test with CFRP reinforced concrete specimen was maked out, and a calculation model of arbitrary point interfacial shear stress and strain was put forward based on elasticity theory.Computation result indicates that the computation result of stresses is coincidence with the test result, the model is feasible; the computation value of interfacial ultimate shear strength is 3.96 MPa, so the shear stress should be less than the value in order to prevent the debonding failure.
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Key words:
- bridge engineering /
- CFRP /
- debonding failure /
- interfacial stresses /
- tensile test
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表 1 材料性能
Table 1. Performances of materials
种类 厚度/mm 抗拉强度/MPa 弹性模量/GPa 剪切模量/GPa CFRP 0.167 3500 235 — 环氧树脂 — 47.1 3.1 1.2 表 2 拉应变
Table 2. Tensile strain
με 载荷/kN 位置/mm 0 40 80 120 160 200 6 1 12 16 17 25 113 8 3 19 24 25 39 159 10 8 28 32 35 54 219 12 16 43 56 88 112 381 14 80 99 90 132 242 667 16 95 117 120 202 281 1459 -
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