Shear behaviour of lightweight RC beams strengthened by NSM GFRP bars

• Main Authors: Al-Thairy, Haitham, Youssef, Anees Jassim
• Format: Conference Proceeding
• Language: English
• Subjects: Diameters; Failure modes; Fiber reinforced polymers; Glass fiber reinforced plastics; Inclination angle; Lightweight; Reinforced concrete; Shear strength; Ultimate loads
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0202232

The NSM technique has been used as a contemporary method to fix flaws in structural parts and improve their flexural and shear strength. For this method to work, a number of practical experiments were carried out to understand the behavior of the component that was fortified using the NSM technique for flexure and shear. This research presents an experimental study on the shear behavior of lightweight reinforced concrete (LWRC) beams strengthened in shear by NSM glass fiber reinforced polymer (GFRP) bars. Six LWRC beam specimens with a cross section dimension of 160 mm x 250 mm and a total length of 1700 mm were used in the experimental testing. The control specimen was an un-strengthened LWRC beam, whereas the other five beams were shear-strengthened using various numbers and configurations of NSM GFRP. The spacing, inclination angle, and diameter of the NSM bars used in the strengthening of the LWRC beams are the primary characteristics evaluated in the experiment. All LWRC beams are subject to two point loads until failure. The load-displacement curves, crack patterns, and failure modes of all RC beam specimens were monitored, recorded, and evaluated in this study. Results have shown The sample SG6 (150mm) 45° showed the highest increase in the ultimate load of the strengthened beams, reaching 149% compared with the control beam, while the sample SG6 (300mm) 90° showed the lower increase in the ultimate load of the strengthened beams reaching 38.5% compared with the control beam. The results also showed that GFRP bars work to improve the shear strength of test samples that were strengthened using the traditional NSM method.