Deformation and strength of grouted sleeve connectors in pre‐fabricated concrete structures: Mechanisms and analytical modeling

Abstract Grouted sleeve connectors (GSCs) are widely used in precast/prefabricated concrete structures. To ensure force transfer, connectors are often overdesigned in length. This practice has an unintended consequence of reducing the plastic deformation capacity of the connection region and hence the displacement ductility of the precast structure as a whole. A more accurate analysis of the bond behavior of GSCs therefore becomes essential to enable optimal design of the GSCs. This paper presents an analytical model for the prediction of the bond‐slip behavior of GSCs, accounting for the local bond behavior under sleeve confinement and the bond stress distribution along the embedded rebar. To model the bond stress distributions in GSCs, two characteristic length scenarios, namely “short” and “long” scenarios, are classified. Other important features along the bonded rebar, including the development of a conical damage zone near the ends of the connectors, the bond deterioration in the yielding rebar region and corresponding bond redistribution, are also incorporated. The analytical model is capable of capturing the bond behavior in GSCs and predicting accurately the overall deformation and failure modes. The model is validated with relevant experimental results. A subsequent parametric study investigates the effect of connector length on the overall deformation capacity of a connection region. It is demonstrated that the GSC length has a remarkable impact on the overall deformation capacity of a connection region, and therefore a more accurate design of the connector length can play a significant role in achieving a desirable ductile performance while ensuring the safety of the connection in a pre‐fabricated RC structure.