PSI - Issue 78

Rawand Alnsour et al. / Procedia Structural Integrity 78 (2026) 1261–1268

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solutions have been developed for RC beams to address shear deficiency, including externally bonded steel plates (Ganesh & Murthy, 2019a), concrete jacketing (Raval & Dave, 2013), fiber-reinforced laminates or sheets (Askar et al., 2022; Belarbi & Acun, 2013; Colalillo & Sheikh, 2012; Kar & Biswal, 2021) hybrid techniques (Ebead & Saeed, 2013; Ruano et al., 2014) and mechanical anchoring systems, (Godat et al., 2020). Addressing shear weaknesses in beams is a foundation for improving the strength and longevity of structural frameworks. This review investigates conventional and contemporary methods for retrofitting RC beams specifically against shear deficiencies, which remain a critical challenge in structural safety. The analysis focuses on the mechanical performance, ease of installation, and applicability of these methods, particularly in the context of seismic upgrading. Among the practical challenges discussed, limited accessibility in confined spaces emerges as a significant factor affecting the feasibility of several strengthening techniques, as illustrated in Fig. 1 (https://theconstructor.org/structural-engg/rcc-beams-strengthening-shear-frp-plate/15148/). Therefore, this paper focuses on summarizing and comparing the most widely used shear retrofitting approaches, highlighting their respective advantages and limitations to support informed selection in engineering practice.

Fig. 1. Limited accessibility for confined spaces.

2. Retrofitting methods 2.1 Externally bonded steel plates

The steel plates technique is considered one of the earliest and most effective methods for strengthening and retrofitting RC beams in shear (Swamy et al., 1996), as they are bonded to the sides of the RC beam using adhesive or anchor bolts. This method significantly enhances shear resistance, particularly through the use of anchor bolts, which help minimize debonding and improve overall performance. However, the system faces challenges such as corrosion and the added weight of steel plates, along with the potential for brittle failure due to debonding or separation of the concrete cover under shear forces (Barnes et al., 2001; Ganesh & Murthy, 2019a). Fig. 2 (a) and (b) (Thamrin et al., 2023) illustrate an RC beam strengthened in shear with externally bonded steel plates.

(b)

(a)

Fig. 2. (a); (b) Steel plate patterns for shear strengthening (Thamrin et al., 2023).

2.2 Concrete jacketing This method is a traditional approach for enhancing the shear strength of beams by increasing their cross-sectional area through the addition of concrete and reinforcement around the existing member. It also improves the member’s ductility and energy absorption capacity. However, it presents several common drawbacks, including a substantial