Issue 78

D. D. Joshi et alii, Fracture and Structural Integrity, 78 (2026) 315-345; DOI: 10.3221/IGF-ESIS.78-19

strengthened with glass fiber mesh. The experimental findings were further validated using finite element models and good correlation was observed. Alkhawaldeh and Al-Rousan [74] employed stainless-steel expanded metal sheet mesh (SSEMSM) for strengthening of RC beam-column joints. Specimens strengthened using one and two layers of SSEMSM, were exposed to elevated temperatures of 400 °C and 600 °C. Subsequently, the strengthened specimens were tested under quasi-static cyclic loading. The results showed a significant improvement in the cyclic performance of non-ductile RC beam-column joints strengthened with the proposed SSEMSM technique, even after exposure to high temperatures. Xie et al. [75] proposed a strengthening technique for existing RC shear walls using steel wire mesh and polymer mortar. Experimental investigations were carried out on five RC shear wall specimens subjected to cyclic lateral loading. Different configurations of mesh ratios and wrapping schemes were considered. The results showed that the proposed strengthening method delayed the initiation of shear cracks and effectively controlled crack propagation. The average lateral load capacity of the strengthened shear walls increased by approximately 55% compared to the control specimen. It was also observed that wrapping of steel wire mesh around the shear wall performed superior compared to applying the mesh only on exposed surface of wall. In addition, a theoretical model was proposed to estimate the load-carrying capacity of the strengthened shear walls. SSWM FOR STRUCTURAL STRENGTHENING - A WAY FORWARD ignificant scope exists to extend the current research to achieve a better understanding of SSWM behaviour and broader practical applicability, by addressing the following aspects. The use of SSWM for enhancing progressive collapse resistance has not yet been fully explored. Future studies should evaluate its effectiveness under different column removal scenarios for both RC and precast structural systems. Key parameters, such as strengthening configuration and number of mesh layers, need to be examined in detail. Investigations could cover a range of specimens, from planar beam-column subassemblies to three-dimensional (3-D) beam-slab-column substructures under various column-removal conditions, considering slab effects and the influence of transverse beams. Studies on full-scale SSWM strengthened substructure are needed to better represent actual structural behaviour. The role of SSWM as an external reinforcement in facilitating load redistribution requires thorough investigation during different load-transfer mechanisms, such as flexural action, compressive arch action and catenary action. For precast system, progressive collapse behaviour of beam-column assemblies should be examined by considering different detailing configurations in the joint region, covering a wide range of practical connection types. This would make the findings more generalizable and relevant for practicing engineers. In addition to beam-column joints, the use of SSWM may also be explored for connections between other precast elements, such as beam-to-beam, beam-to-slab, column-to-column, slab to-wall and column-to-footing connections. The feasibility of applying SSWM to dry precast connections also requires special attention, with a focus on proper bonding, joint integrity, load transfer mechanisms and governing failure modes. There is a need to explore different alternative bonding materials, such as epoxy-based adhesives, cementitious or heat resistant chemical adhesives. The use of such alternatives could improve the overall performance of SSWM strengthening systems during fire events and reduce the risk of fire induced progressive collapse. A hybrid composites could also be developed by combining SSWM with FRP systems. Such hybrid configurations should be explored for strengthening of RC and precast assemblies under progressive collapse scenario. Analytical methods and numerical models should be developed and validated to simulate the response of SSWM strengthened RC and precast assemblies under progressive collapse scenarios. Incorporating bond-slip behaviour at the interfaces between SSWM and concrete, reinforcement and concrete, as well as between precast and cast-in-place concrete, would improve the reliability of such models. These efforts would support detailed parametric studies and provide a clearer understanding of the contribution of SSWM to progressive collapse mitigation. Experimental, numerical and analytical studies in these areas would help the development of design recommendations and support the practical use of SSWM for strengthening of RC and precast structures against progressive collapse. C ONCLUDING REMARKS his review presents an overview of strengthening techniques used to enhance the progressive collapse resistance of RC and precast concrete assemblies. Methods such as externally bonded FRP systems, steel plate systems, external cable systems, near-surface mounted reinforcement, engineered cementitious composites and their hybrid combinations have shown varying levels of effectiveness in mitigating progressive collapse in RC and precast assemblies. S T

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