EXPERIMENTAL STUDY AND BEARING CAPACITY ANALYSIS OF RC TWO-WAY SLABS STRENGTHENED WITH FRP STRIPS
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摘要: 对3组9个简支外贴纤维条带加固RC双向板进行试验研究。外贴纤维条带采用均匀布置和跨中板带加密布置两种粘贴方式。试验中考察了加固板的抗裂性能、变形能力、刚度、裂缝分布等受力性能,对外贴玻璃纤维条带加固RC双向板极限状态时的破坏特征和极限承载能力进行了重点研究。研究结果表明:外贴纤维条带加固能有效延缓裂缝的出现、抑制裂缝的开展、改善结构的抗裂性能及提高结构的极限承载力,加固板的刚度也有一定的提高,但延性略有降低。通过对试验数据的回归,提出双向受力作用下,纤维剥离应变计算公式,分析普通板和纤维加固板板单元截面抵抗弯矩的区别,探讨外贴纤维条带对双向板极限承载力的贡献以及纤维加固双向板板单元截面抵抗弯矩的取值。采用屈服线理论,建立纤维加固板的极限承载力计算公式,计算结果与试验值吻合较好。研究成果可供实际加固改造工程参考。Abstract: It is presented an experimental study on 9 pieces of simple supported RC two-way slabs strengthened with external bonded glass fiber reinforced polymer(GFRP) strips.The cracking behavior,deformation behavior,failure characteristic and mechanism and ultimate bearing capacity of strengthened RC two-way slabs were studied.The test results indicated that the GFRP strips were effective in appreciably improving the cracking behavior and deflection behavior and increasing the flexural stiffness,cracking load and ultimate bearing capacity of the strengthened slabs.But the ductility of the strengthened slabs was reduced.The yield-line failure modes of strengthened RC two-way slabs were analyzed based on the experimental results.Based on the regression of test results,the maximum strain of FRP under two-way loading is obtained.By adopting of yield-line theory,a calculation formula for the determination of the ultimate capacity of the strengthened slabs was obtained.The analytical results are in good agreement with the test results.This study may be a reference for actual strengthening projects.
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Key words:
- glass fiber /
- strengthening /
- RC two-way slabs /
- debonding /
- yield-line theory
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