Comparative Study of Plasticity-Based Steel–Concrete Bond Stress and Codal Development Length in RC Structures with Formulations Proposed in CEB-FIP 2009, IS456:2000 and ACI 408R-03

The behaviour of steel–concrete bond is critical to the performance of reinforced concrete structures. Bond length is a key parameter that affects the load-carrying capacity of such structures. However, the linearized model commonly used to calculate bond length is not inclusive of the plasticity of concrete and steel. This oversimplification can lead to inaccurate results. In this paper, we compare the formulations for bond length as proposed by IS456:2000 (IS 456. Code of practice for plain and reinforced concrete. In: Bureau of Indian Standards (2000), ACI 408R-03 (ACI Committee 408. 408R-03: Bond and development of straight reinforcing bars in tension. In: Technical Documents (24)9) and transmission length by CEB-FIP 2009 (CEB-FIP model code 2009: design code. CEB Bulletin No.48, 2009(2009), with a more realistic simulation of the pull-out test. The simulation model incorporates plasticity in concrete using the concrete damage plasticity model (CDPM), classical metal plasticity in steel, and a linearized bond slip model. Our study highlights the significant differences between the bond length parameters obtained using the linearized model and the more realistic simulation. These findings emphasize the importance of considering the plasticity of both concrete and steel in the analysis of bond behaviour between these materials.