Out-of-Plane behavior of clay brick masonry infills contained within RC frames using 3D-Digital image correlation technique

The present study investigated the out-of-plane (OOP) behavior of traditional solid clay brick masonry-infilled reinforced concrete frames for different slenderness ratios, bonding patterns, and connection details to assess the development of arching mechanism, infill-frame interaction, and failure mechanisms. Full-field strain and crack width analysis, failure progression, and out-of-plane deformation characteristics were evaluated using a non-contact 3D-DIC (digital image correlation) technique. The experimental investigation ascertained that full-brick thick lower slenderness ratio (13.4) specimens observed higher capacity (3.7 times), deformation ability (>1.2 times), and energy dissipation characteristics (>3.5 times) compared to half-brick thick slender (28.8) specimens. The presence of tie bars enhanced the stability of the wall against out-of-plane failure. However, it did not significantly modify the load and deformation behavior in the peak and post-peak stages. The OOP defor-mation profiles, arching mechanism, and the distributed damage in infill in lower slenderness ratio specimens, which led to higher OOP lateral load resistance, were precisely captured using the 3D-DIC technique. The in-crease in width of the cracks (1.6-2.9 times) in Flemish bond (lower slenderness ratio) specimens compared to their running bond counterparts was accurately appraised using the DIC. Based on the experimental results, a unified out-of-plane lateral load-deflection idealized model was proposed. The appropriateness of the proposed model was further verified by comparing it with previously developed models and experimental studies. The research study revealed that the out-of-plane lateral load behavior of infilled frames was significantly modified due to strong and stiffer solid clay masonry, considering different structural bonding patterns and slenderness ratios. The 3D-DIC technique was found to be a resourceful tool for comprehending the deformation and damage characteristics of infilled frames, especially under out-of-plane lateral loads.