Study On Seismic Behavior Of Prefabricated High Strength Concrete Pipe Column With Mixed Reinforcement

With the quickly changes of urban construction and increase of economic level and the quality of life,green,energy saving and high efficiency have become the theme of development of construction industry.Architectural industrialization and green construction have become inevitable development direction.As a new column component in prefabricated frames,prefabricated high strength concrete pipe column with mixed reinforcement was proposed in this paper,which is based on the existing production process of PHC.It gives full play to excellent properties of high strength concrete and prestressed steel bars.The seismic behavior is improved by adding non-prestressed reinforcement.A method combined with theoretical analysis,model test and numerical simulation was used for popularization and further study on the properties of the new component.Seismic behavior and bearing capacity of prefabricated high strength concrete pipe column with mixed reinforcement were studied and its applicability and economic benefit were discussed.The research results and innovation of this paper are obtained as follows:1.The innovative prefabricated strip beam was designed and prefabricated column base was made,providing a joint form of pipe column base for reference.2.Sufficient study on seismic behavior and bearing capacity of prefabricated pipe column were conducted in this paper from several aspects including development of cracks,failure mode,load-displacement curve,skeleton curve and stiffness degradation,etc.The results showed that: stiffness and bearing capacity of prefabricated high strength concrete pipe column with mixed reinforcement have significantly promotion with the increase of axial compression ratio.Ductility of the specimens are improved by adding high strength reinforcement.The specimens show certain energy dissipation capacity,whose drift ratio is between 1/85 and 1/64 while ultimate displacement angle is between 1/34 and 1/25.3.The formulas of normal section bearing capacity and inclined section bearing capacity are proposed in this paper.Through the comparison of calculated results and test results,the formulas proposed were proved to have good reflect of bearing capacity of pipe columns and have certain safety stock.4.A new design is proposed in this paper which replaces H section steel masts with prefabricated pipe columns in portal frames.Feasibility and good economic benefit of the new design are proved according to the research results in previous paper.