Advances in Engineering Design Technology Vol. 4(3) 2022 pp. 21-30 ISSN-2682-5848

 

U-Wrapped Configuration Variation on Shear Strengthening of RC Beam by Carbon Fiber Reinforced Polymer Fabricel

John A. TrustGod, Osuji S. Obinna, Nwankwo Ebuka

Abstract

The demand to upgrade deficient structural members has grown over the years. According to experimental and numerical publications in this area, the application of fiber-reinforced polymer (FRP) to strengthen reinforce concrete (RC) elements in shear is an effective means. Strengthening RC beams with carbon FRP has several advantages over the steel plate strengthening method, for instance, ease of application, weight to high strength ratio, and durability. This paper studies the effect of U-wrapped configuration variation on the shear strengthening of RC beams by carbon FRP fabrics. Three shear strengthening U-wrapped configurations of CFRP fabric were studied: 200 g/m2 and 300 g/m2 of CFRP fabric strips of 100 mm by 400 mm applied as U-wrapped, spaced 250 mm center to center as a model of the prototype; 200g/m2 and 300 g/m2 of CFRP fabric measured 250 mm by 367 mm applied as U-wrapped in the shear spans from the bottom of the beam as a model of the prototype; 200 g/m2 and 300 g/m2 CFRP fabric strips of 300mm by 400mm applied as strip U-wrapped, spaced 375 mm center to center as a model of the prototype. Thirteen (13) RC beams (100 x 150 x 1100 mm) with flexural internal reinforcement (As =2Φ10 mm), compression reinforcement (AS =2Φ8 mm) and shear reinforcement (Asv =Φ6 mm @ 220 mm c/c). The beams were strengthened in shear as described above with bond thickness of 2 mm, 4 mm, and 6 mm. All the beam samples were subjected to two-point load application to examine the CFRP contribution to shear strength. The beams strengthened by U-wrapped CFRP fabrics improved the shear capacity of the control beam by 40%. The U-wrap configurations, which were designed to simulate the conventional method of shear reinforcement placement along the longitudinal axis of the beam, provided the best results compared to the other U-wrap configurations. The CFRP fabric to bond thickness ratio should not be more than 0.069. According to ACI 440 2R 17, a complete-wrapping configuration provides the best result in terms of increasing the shear strength of the strengthened RC beams. However, the study proves that in the absence of complete-wrapped configurations, U-wrap configurations simulating the conventional shear reinforcement placement along the horizontal axis can also be employed effectively. Bond thickness was also observed to have a significant impact on the shear strength of RC beams

How to cite this article:John A. TrustGoda, Osuji S. Obinnab, Nwankwo Ebuka. (2022). U-Wrapped Configuration Variation on Shear Strengthening of RC Beam by Carbon Fiber Reinforced Polymer Fabric. Advances in Engineering Design Technology, 4(3), 21–30. https://doi.org/10.5281/zenodo.7487257