The Axial Compressive Performance Study Of A Reactive Powder Concrete Precast Tube Concrete Composite Columns

Reactive Powder Concrete(RPC) is a kind of ultra-high performance concrete which has ultra-high strength, durability, ductility and energy dissipation. Precast RPC tube composite column is a new kind of composite structure which was composed by precast RPC tube and core concrete, and this kind of structure can full play the advantages of combination effects of ultra-high compression performance and confined concrete, and has the advantages of high axial bearing capacity, fire resistance performance, durability, convenience of construction and ecological benefits,. The innovative works in this thesis are in the combinative field between ultra-high performance concrete and composite structures.In this paper, the five groups of RPC tube composite column tests were executed. The main research parameters are the thickness of RPC tube column and the stirrups ratio. Force- deformation relationships for the RPC tube composite columns, strain development of materials and failure modes were obtained from experiments. The composite column bearing capacity and the existing confined concrete column m odels were compared and analyzed, which laid the foundation of future research. Specific contents are as follows:First chapter: the basic of ultra-high performance concrete and confined concrete are introduced. The application and extension of reactive powder concrete are detailed. Based on the excellent performance of RPC and the basic structure type of composite column, a new kind of composite column--RPC tube composite column is invented which structure type and features are emphasized.Second chapter: the scheme of composite column axial compressive strength testis are proposed, and the design and manufacture of specimens are detailed. The experiment of material mixture ratio making up RPC precast tube is performed. The processing of RPC precast tube is manufactured.Third chapter: the test of axial compression from 5 groups of RPC tube composite column was promoted which include the force-deformation relationships, materials strains and failure modes. The force analysis of RPC tube composite column with different precast tube thickness and stirrups distance is investigated.Last chapter: several kinds of models of confined concrete theory are introduced, and the approximation bearing capacity of specimens, which is calculated by Mander model theory, are compared with the test results. The purpose is to examine the theoretical formula on applicability of this new type of composite column, which provides the theoretical reference for further studying the basic properties of the RPC tube composite column...