Experimental Comparison of Different Types of FRP Wrapping in Repairing of RC Deep Beams with Circular Openings

Abstract

Openings of reinforced concrete (RC) deep beams can be used to pass electrical, mechanical, and architectural equipment. A comparative experimental study of fiber reinforced polymer (FRP) type on the performance of deep RC beams with the circular opening was the most important purpose of this study. The variables were FRP type (carbon, glass, and aramid) and the number of layers (1, 2, and 3). The geometric and rebar characteristics of the beams were considered constant in all cases. Deep RC beams were constructed, and their response to four-point loading was evaluated. Depending on the layers (1, 2 and, 3), aramid, carbon and glass fiber reinforced polymers (AFRP, CFRP, and GFRP) sheets increased the maximum load by about 65 to 94%, 87 to 130%, and 133 to 196%, respectively. In RC deep beams retrofitted with GFRP sheets, the sheet separation from the beam surface decreased with expanding the number of layers. The CFRP sheets debonded from the beam surface at the supports along the center of the circular opening. CFRP showed much better performance in energy absorption capacity and load capacity than AFRP and GFRP. The CFRP were debonded from the beam surface at the moment of rupture. However, no significant separation was observed in RC deep beams retrofitted with AFRP and GFRP sheets. SEM images of the cores specimens showed that the fracture surface of the specimens extracted from the beam retrofitted with GFRP and CFRP sheets was much rougher than the control specimen, which indicates a stronger bond between the concrete components.

Comprehensive Empirical Modeling of Shear Strength Prediction in Reinforced Concrete Deep Beams

“…Eyad et al [5], explored the impact of confining the strut region through the use of struts reinforcement, while Eyad et al [6], proposed an empirical formula for the strut efficiency factor (Bs) in RC deep beams, derived from a comprehensive analytical study based on the strut and tie model. Other researchers have numerically investigated main parameters influencing the behavior and shear capacity of RC deep beams [7,8]. Despite numerous experimental and numerical investigations into reinforced concrete deep beams, which have considered factors such as concrete compressive strength, (av/d) ratio, and reinforcement directions in relation to shear capacity, the current ACI 318R-5 [1] code and BS 8110 [9] codes still do not incorporate these factors comprehensively.…”

Strengthening of RC Beams using Steel Plate-Fiber Concrete Composite Jackets (Finite Element Simulation and Experimental Investigation)

“…The proposed steel plates increased the bearing capacity by 7 times [14]. Rahimi et al [15] investigated the effect of aramid fiber reinforcement polymer (AFRP) and glass fiber reinforcement polymer (GFRP) on the strengthened deep RC beams and compared their response with the performance of CFRP sheets. The number of FRP layers was 1, 2, and 3.…”

“…The number of FRP layers was 1, 2, and 3. Depending on the number of sheets, the addition of AFRP, CFRP, and GFRP sheets increased the bearing capacity by 65 to 94%, 87 to 130%, and 96 to 133%, respectively [15]. Artiningsih et al [16] strengthened RC beams using the glass fiber jacketing system.…”

“…The accuracy of the analysis method was evaluated by modeling RC beams fabricated in the laboratory, and a good agreement was observed. Variables in the finite element method (FEM) analysis include the strength class of concrete used in the main beam (15,20, and 25 MPa), the beam length (1.4 and 2.8 m), the type of jackets (RC jacket, SPFCJ, and CFRP sheet), and jacket thickness (40, 60 and 80 mm). SPFCJ is effective for all three concrete grades and increased the energy absorption capacity by 1.88, 2.07, and 2.25 times, respectively.…”

Experimental Study on Bonding CFRP to Fiber Concrete Beam Considering the Effect of using Nanographene Oxide in Improving the Mechanical Properties of Polyamine Resin

“…Steel binding, increasing the cross-sectional area via concreting and adding rebars, strengthening via steel plates, epoxy injection, integration with prestressed cables, employing seismic techniques, and using fiber-reinforcement polymer (FRP) are examples of these methods. Among composites, the carbon-fiber-reinforced type is used more frequently than other types for concrete structures due to its higher strength, higher stiffness-to-weight ratio, better corrosion resistance, shorter construction time, and better durability [1][2][3][4][5][6]. Numerous studies have been conducted in recent years on the strengthening of reinforced concrete members, such as beams [7][8][9][10], slabs, columns [11], beam-to-column [12], connections, and other members [13].…”