Investigation on the out-of-plane behavior of castellated steel reinforced concrete walls under eccentric loading

To leverage the advantages of the compression-bending performance of castellated steel reinforced concrete structures, this paper presented a castellated steel reinforced concrete (CSRC) wall. One reinforced concrete (RC) wall specimen and five CSRC wall specimens were designed and tested under eccentric loads to examine the effects of the steel skeleton configuration, load eccentricity, and longitudinal reinforcement ratio on out-of-plane eccentric compression performance. The failure modes, vertical load-lateral deformations curves, and the strain distributions in the structural steel and concrete were analyzed. The test results indicated that the failure modes of CSRC wall specimens were similar to those of RC wall specimens, and the CSRC walls demonstrated excellent composite action. As the load eccentricity increased, the failure mode of the CSRC wall specimens transitioned from compression failure to a combination of compression and bending failure. Concurrently, the initial flexural stiffness and load-bearing capacity of the CSRC wall specimens decreased gradually, while the impact of the longitudinal reinforcement ratio on these properties became increasingly significant. Based on the test results and elastic-plastic stress theory, a calculation method was developed to predict the load-bearing capacity and bending capacity of the CSRC walls under eccentric compression loads. The calculation results showed good agreement with the test results. The simplified vertical load-bending moment interaction curves, obtained from the calculations, compared the load-bearing capacity and bending capacity of RC and CSRC walls, providing a reference for the engineering application of CSRC walls.