The progressive collapse of reinforced concrete (RC) frame structures, often triggered by the sudden loss of a column, poses a severe threat to structural integrity and public safety. With many structural design codes addressing this phenomenon only recently, retrofitting existing buildings has become a critical necessity. This study introduces an innovative retrofit technique based on the “partially out-shift plastic zone” (POSPZ) strategy, aimed at redistributing plastic deformation regions to mitigate collapse risk. To actualize this concept, corrugated steel plates are strategically integrated into RC joints, enhancing their post-yield behavior. An experimental campaign was conducted to characterize the tensile behavior of corrugated plates with varying geometries, thicknesses, and wave counts. The mechanical response was thoroughly analyzed through numerical simulations, optimizing parameters for maximum energy absorption and stress redistribution. The incorporation of corrugated plates into RC beam-column sub-assemblages yielded remarkable improvements in load-carrying capacity and energy dissipation, particularly during the post-plastic phase, by leveraging the straightening behavior of the corrugated profile. Finite Element (FE) analyses revealed a significant enhancement in catenary action, improved stress distribution in reinforcement, and an outward shift of plastic zones. Notably, the 3-wave corrugated plate configuration increased the catenary action enhancement factor by up to 159.5%, signifying superior structural resilience. These findings provide compelling evidence for the efficacy of POSPZ-based retrofitting, offering a practical and efficient pathway to enhance the robustness of existing RC frames against progressive collapse.

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