Seismic Behavior Of Prefabricated Reinforced Concrete Column And Column Longitudinal Reinforcement Anchor Connection

Prefabricated buildings are the representative of industrialization process of building and occupy an increasingly important position in the construction market.Different from the traditional construction of cast-in-place operations,prefabricated buildings have the advantages of short construction period,high precision components and good product quality.More importantly,prefabricated buildings have great advantages in solving problems of on-site wet operations,environmental issues,waste of resource materials,and low utilization.Moreover,frame column have a great role on the overall structure as the main vertical structural member of the structure.At present,the connection form of the prefabricated frame column joints is mainly the sleeve grouting connection.And a connection form of the frame column joints with a more convenient construction process,higher assembly fault tolerance and better performance is proposed to examine the seismic performance of the frame column joints.In this dissertation,the main efforts are listed as follows:(1)A frame-column connection of longitudinal ribs wrapped by corrugated grouting was proposed.Four full-scale prefabricated frame columns were fabricated and a cast-in-place test specimen was produced for comparison.The test parameters were set to an axial compression ratio of 0.4 and 0.6,an assembly position of 1 column section height and 2 column section heights.(2)Pseudo-static test is carried out to investigate the seismic behavior of precast reinforced concrete columns by applying low-cycle reciprocating loads.The failure characteristics of specimens,hysteresis curves,skeleton curves,ductility properties,stiffness degradation and energy dissipation capacity,were analyzed by experimental results.The results showed that use of the proposed longitudinal column lapped bellows grouted anchored of frame column specimens have its advantages on the resistance to failure,and the yield point of longitudinal steel bar,especially in the prefabricated assembly column specimen,is significantly delayed due to the presence of grouting anchorage.Although the ductility of prefabricated test specimens is lower than cast-in-place specimens,the stiffness degradation and energy dissipation capacity are comparable to those of cast-in-place specimens.The ductility of the specimens does not change when the assembly position of the prefabricated specimen column and the column change,but it has certain influence on the stiffness and strength degradation and the energy dissipation capacity of specimens.It is obvious that the deterioration velocity of stiffness of specimens assembled at the height of 2 column sections is significantly slower than at a height of 1 column section.And the energy dissipation capacity is raised substantially especially at a shaft pressure ratio of 0.4,which is increased by about 20%.(3)The stress conditions of test specimens were simulated using the ABAQUS finite element simulation software,and the predicated results obtained by ABAQUS is compared with experimental results to assess the coupling degree.The comparison between the simulation results of the finite element analysis software and the test results,it can be seen that the simulated plastic damage area is close to the final damage position of specimens.Due to the assumptions of continuity and homogeneity during simulation,the simulated seismic performance is slightly better than the test results,but the simulated seismic behavior of precast and cast-in-place columns is consistent with the experimental results.