Experimental study on the effectiveness of strengthening of reinforced concrete beams with opening in shear span using CFRP sheets

Abstract

In reinforced concrete beams, the opening is frequently required for the passage of utility ducts and/or pipes. The presence of such web openings leads to a reduction of the strength and stiffness of the beam. To ensurethe safety of the reinforced concrete beam, a strengthening system around the opening is necessary. This paperaims to contribute to a better understanding of the shear behavior of reinforced concrete beams with openingsin the shear span, strengthened with Carbon fiber-reinforced polymer (CFRP) sheets. The study is based on anexperimental program carried out on six beams. All beam specimens were 850 mm long with a cross-sectionof 150 × 250 mm and a shear span to beam depth ratio (a/d) of 1.48. One beam without any openings served asthe control specimen, while the remaining five beams featured circular or rectangular openings within the shearspan and with/without shear strengthening using CFRP sheets around the openings. The test results obtainedfrom this experimental program provide insights into the shear behavior of beams with openings, both with andwithout strengthening using CFRP sheets. Additionally, the potential advantages and effectiveness of employingCFRP strengthening techniques for opening strengthening are investigated and discussed.