Theoretical Analysis And Numerical Simulation Of A Novel Precast Concrete Joint

In this paper,a novel precast concrete beam-column and column-column joint with advantages of clear force transmission and convenient construction was proposed.The novel precast concrete beam-column and column-column joint consisted of alveolar section in the splicing region and lock device-lock configuration.The alveolar section at the position of the beam-column joint is serrated,the other is prismatic to meet the respective force characteristics.The longitudinal reinforcement lock device-lock configuration means that a steel member containing a slot is embedded in the splicing end of the precast component,which was connected by wedged the corresponding shape steel locks during on-site construction.Based on the truss-arch model,the formulae of shear bearing capacity and flexural capacity of the new section as well as the local bearing capacity of partial alveolar were proposed,respectively.Practical example and the corresponding finite element models were calculated to validate aforementioned formulae.The results show that the new type of precast joints exhibit comparable performances as the cast-in-situ concrete joints.The results of the ultimate shear bearing capacity obtained from the theoretical formulae to the finite element analysis agrees well with each other.According to the comparison of the precast components and the cast-in-situ components in Abaqus,it is illustrated that the lock device lock can effectively transfer the longitudinal stress,and the alveolar type configuration can significantly enhance the shear strength of the section.It is suggested to fill the gap by using high-strength grouting material in the splicing surface so as to enhance the integrity of the joint.Similarly,the shear capacity formulae of the novel precast column-column joint are given based on the diagonal compression strut model,the local bearing capacity formulae of partial alveolar under the condition of bending were proposed.Practical example and the corresponding finite element models were calculated to verify the correctness of aforementioned formulae,the results of the ultimate bearing capacity based on the derivation formula and the finite element analysis agrees well with each other.Parameters analysis of the precast column seismic performance were made at the end of the paper,the effects of axial compression ratio,stirrup ratio and number of slots on seismic performance of joints were analyzed.The results show that the axial compression ratio is significant for the ultimate bearing capacity,the effect of the increasing of stirrup ratio is to improve the ductility of the precast column,the bearing capacity of the precast column increases as the number of slots increases.