Mechanical performance of prefabricated concrete beam-column joints with double-grouted sleeve connectors: A numerical and theoretical study

This paper presents a systematic numerical study on the structural performance of a newly developed quick-buildable beam-column joint with double-grouted sleeves considering its surface-to-surface contact behaviour between the prefabricated concrete and grouting mortar and strain penetration of the transition rebar. Theoretical analysis is also conducted to predict the load-bearing capacity of the proposed connection. After validation with experimental data, the finite element model is employed to investigate the effects of different factors including protruding beam length and grouting mortar thickness on the structural behaviour of the joint. Results indicate that the maximum stress of the reinforcing bars in the joint with no protruding beam is approximately 15.0% greater than that with a protruding beam, while the maximum stress of the joint anchorage bars decreases by around 87.0% when the short sleeves are placed completely in the joint core area. As the protruding beam length increases, the maximum crack width drops rapidly first and then slowly with a turning point of 1.36 times the short sleeve length, and the highest load-bearing capacity is achieved when the protruding beam length and short sleeve length equal. With the rising grouting mortar thickness, the maximum stress of the transition rebar reduces rapidly first and then slowly with an inflexion point of 50 mm. The change in eccentricity of the transition rebar leads to an around 3% change in the load-bearing capacity of the joint without a projecting beam. The theoretical predictions are in satisfactory agreement with numerical results and can be adopted for practical engineering design.