Issue 78

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

Fig. 2 represents the VOSviewer based keyword co-occurrence network, illustrating the thematic distribution and evolution of research on strengthening of RC and precast systems against progressive collapse. The size of each node represents the frequency of occurrence of the keyword, while the links indicate the strength of co-occurrence between different terms. The color gradient reflects the temporal evolution of research focus, with earlier studies shown in blue and more recent trends in yellow. It is evident that “progressive collapse,” and “strengthening” form the central cluster, indicating their dominant role in the literature. This visualization supports the systematic selection of literature by identifying key research domains and ensuring that the review remains focused on studies addressing progressive collapse mitigation through strengthening techniques. Notably, the minimal links between the terms related to “stainless steel wire mesh” and “strengthening” reflects its application remains largely unexplored. Further, a disconnect between “progressive collapse” and “stainless steel wire mesh” highlights a research gap indicating that its application for progressive collapse resistance has not been attempted by researchers. O VERVIEW OF EXISTING REVIEW STUDIES ON PROGRESSIVE COLLAPSE lkady et al. [5] presented a comprehensive review on progressive collapse of building structures. The study presents key terminologies and definitions along with types of progressive collapse. It also discusses various design guidelines and outlines commonly used design approaches and investigation methods. Strategies for mitigation and prevention of progressive collapse are also reviewed by the authors. In addition, recent advances such as the use of physics-based simulations, game engines and machine learning techniques are summarized. Based on the review, the authors proposed the specific need for further research in the field of progressive collapse. Kiakojouri et al. [6] reported a comprehensive review of progressive collapse studies on framed building structures. The authors incorporated several key aspects, including a compilation of major structural failures, a timeline outlining the development of relevant guidelines and codes and notable progressive collapse events. An overview of existing research approaches, mainly including experimental, numerical and analytical investigations, was presented. The review further discussed progressive collapse mechanisms and typologies, as well as various triggering events such as blast, fire, impact, seismic actions and multi-hazard scenarios. In conclusion, the authors identified several research gaps and highlighted future perspectives and potential directions for further investigation in this field. Alshaikh et al. [7] presented a comprehensive review of studies on the progressive collapse resistance of precast beam column subassemblies, with and without slab effects. In addition to conceptual aspects and progressive collapse mechanisms, the researchers compiled the structural response and failure modes observed in precast beam-column assemblies under progressive collapse scenarios. The review encompassed both the experimental and numerical investigations, along with an overview of strengthening approaches for precast beam-column assemblies to mitigate progressive collapse. Furthermore, Alshaikh et al. [8] presented a review of experimental studies on the progressive collapse behaviour of RC structures, considering different types of test specimens, including beam-column assemblies with and without transverse beams and/or slabs. The authors summarized testing procedures adopted during experiments, the influence of boundary conditions and the role of reinforcement detailing, including seismic detailing. Adam et al. [9] compiled conceptual definitions of progressive collapse and structural robustness, as reported in technical papers, guidelines and standards. The authors also presented bibliometric analyses and statistics of technical publications in Scopus-indexed journals, along with a publication timeline. Moreover, they summarized international codes, design approaches for progressive collapse assessment, experimental testing and numerical studies. S TRENGTHENING OF RC STRUCTURES AGAINST PROGRESSIVE COLLAPSE everal studies have reported different techniques for strengthening of RC structures against progressive collapse. Kiakojouri et al. [10] reviewed different strengthening and retrofitting techniques to mitigate progressive collapse under different scenarios, such as fire, impact and blast. The review discussed the influence of key parameters, such as structural topology, nature of the triggering event, extent of the initial damage, collapse typology and seismic design requirements, on the selection and effectiveness of strengthening strategies. They further summarized different approaches to enhance progressive collapse resistance of various structural systems. In addition, the authors highlighted several research challenges and unresolved issues related to progressive collapse mitigation and outlined future research directions for improving the robustness and progressive collapse resistance of structures. A review of different strengthening techniques E S

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