| Summary: | 碩士 === 中國科技大學 === 土木與防災設計研究所 === 101 === The objective of this study is to examine the effect of carbon fiber reinforced polymer (CFRP) on the shear strength of deep beams with web openings. A total of 21 reinforced concrete deep beams with web openings were tested, 18 of them were made of high-strength concrete and the others were made of normal-strength concrete. In high-strength concrete specimens, twelve were externally wrapped with two layers of CFRP, six of them strengthened in the horizontal direction and the others in the vertical direction. In normal-strength concrete specimens, two were externally wrapped with four layers of CFRP, one of them strengthened in the horizontal direction and the other in the vertical direction.
The test results indicate the shear strength of normal-strength concrete deep beams with web openings strengthened by four layers of CFRP wrapped in the vertical direction can be enhanced by 25%. However, the shear strength of normal-strength concrete deep beams with web openings strengthened by four layers of CFRP wrapped in the horizontal direction can only be enhanced by 18%. The test results indicate the shear strengths of high-strength concrete deep beams with web openings strengthened by two layers of CFRP wrapped in the vertical direction can be enhanced by about 8%. However, the shear strength of high-strength concrete deep beams with web openings strengthened by two layers of CFRP wrapped in the horizontal direction can be enhanced by about 6%. The test results also indicate the shear strengths of deep beams with openings sized 40*40 mm were about 17% higher than that with openings sized 68*68 mm.
The shear strengths of high-strength concrete deep beam, with different size and location of web openings and strengthened by different configuration of CFRP, can be reasonably predicted by the empirical formulas of Kong and Sharp. However, the empirical formulas of Kong and Sharp will obtain non-conservative shear strength predictions in the normal strength concrete deep beams with web openings.
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