Experimental Investigation of Reinforced Concrete Beam with Openings Strengthened Using FRP Sheets under Cyclic Load

Abstract

In this study, the cyclic behavior of reinforced concrete (RC) beam with openings strengthened using carbon fiber-reinforced polymers (FRPs) was experimentally investigated. Seven rectangular RC beams were cast and strengthened through external bonding of carbon fiber-reinforced polymer (CFRP) sheets around the beam web opening with different orientations to evaluate the maximum resistance, secant stiffness, strength degradation, ductility, energy dissipation capacity and behavior of the specimens’ failure mode under cyclic load. One solid beam without an opening (i.e., control specimen) and six beams constructed with circular web openings typically located in the middle of the beam and adjacent to the supports were used in the experiments. Among the six specimens with opening configuration, two beams were unstrengthened, and the remaining four specimens were strengthened with two layers of FRP sheets with vertical and inclined scheme orientation. Numerical studies were performed on ABAQUS software, and finite element modelling analysis results were verified through experiments. Results demonstrated that the use of FRP sheets has a significant effect on the cyclic behavior of RC beams, thereby improving the maximum strength and ultimate displacement to approximately 66.67% and 77.14%, respectively. The validated finite element models serve as a numerical platform to apply beneficial parametric studies, where the effects of opening size and bond length are investigated.

A review on the behaviour of reinforced concrete beams with fibre-reinforced polymer-strengthened web openings

“…the same failure mode of the control beam without a web opening, as shown in Figure 2(b)] (e.g. Abdalla et al, 2003; Aksoylu et al, 2020; Mansur et al, 1999; Pimanmas, 2010; Salih et al, 2020); however, if the FRP-strengthening is insufficient and the shear capacities of the cross-sections in the opening region cannot be restored (i.e. smaller than the flexural capacities of the cross-sections), the beam will still fail by shear in the opening region after the debonding/rupture of FRP.…”

“…A total of 24 experimental studies on the behaviour of RC beams with an FRP-strengthened web opening have been found in the published literature (Abdalla et al, 2003; Abdel-Kareem 2014; Aksoylu et al, 2020; Allam, 2005; Allawi et al, 2020; Almusallam et al, 2018; Arabzadeh and Karimizadeh, 2019; Chin et al, 2012, 2016; Elsanadedy et al, 2019; Hemzah et al, 2020; Hussain and Pimanmas, 2015; Lu et al, 2015; Maaddawy and Ariss, 2012; Maaddawy and Sherif, 2009; Makki et al, 2019; Mansur et al, 1999; Nie et al, 2018, 2020a; Osman et al, 2017b; Pimanmas, 2010; Rahim et al, 2020; Salih et al, 2020; Teng et al, 2013b). The first of these studies was conducted by Mansur et al (1999), in which three RC T-section beams were tested with only one parameter examined (i.e.…”

“…Nie et al, 2020a), as shown in Figure 1(a). The failure of some specimens tested by Almusallam et al (2018), Hemzah et al (2020) and Salih et al (2020) was dominated by the crushing of compressive concrete at the mid-span of the beam, which belongs to a flexural failure mode [as shown in Figure 1(b)]. Besides, two specimens tested by Nie et al (2018) exhibited local flexural failure/mixed flexural and shear failure at the two ends of the chords [as shown in Figure 1(c)].…”

Uso de PRFC para mejorar las propiedades mecánicas del concreto: una revisión

“…Por otra parte, las láminas de PRFC tienen un efecto significativo en el comportamiento cíclico de las vigas de CA, mejorando así la resistencia máxima y el desplazamiento último hasta aproximadamente el 66.67% y el 77.14% en vigas [47] .…”

Experimental and numerical investigation of RC beams strengthened with CFRP composites

“…Test results confirmed validity of the numerical study. Salih et al [25] investigated both experimental and numerical behaviour of RC beams whose openings were strengthened using CFRP. FE results were verified by experiments.…”