Hysteresis performance and rotation modelling of sleeve-type fully-bolted prefabricated joints

In order to achieve rapid construction and reliable connection of precast RC frames， a sleeve-type fully-bolted joint is proposed. The ends of the prefabricated components are reinforced with a steel sleeve-concrete combination. High-strength bolts are pre-built in the sleeve area， and the precast components are rapidly installed using a connection plate. A total of four test specimens were designed for different thicknesses of connecting cover plates. The horizontal hysteresis test study obtained the damage mode， load-displacement hysteresis curve， ultimate bearing capacity， ductility and energy dissipation capacity of this type of joint. The results show that the new joint has a 43% higher ultimate load， 70% higher initial stiffness and nearly 50% higher ductility than the cast-in-place joint， and the equivalent viscous damping coefficient is increased by about two times， which shows better seismic performance. Strain analysis reveals that the cover plate at the joints shows a “stress increase”， but the effect on the overall performance is not apparent. As the thickness of the connection plate increases， the squeezing effect of the sleeve on the concrete increases. Therefore， a connection stiffness ratio of 1.6 is more reasonable. Finally， based on the test results， a trifold moment-turning angle model is established， and the calculated results agree with the test values.