Research On Basic Behaviors And Design Theory Of Steel Reinforced High Strength And High Performance Concrete Beams

Following concrete structure and steel structure, steel reinforced concrete (SRC) structure is another progress for development of buildings structure form, which has excellent mechanical behaviors and good economic benefit. Its benefits have been gradually recognized, but its relevant research is not sufficient. Further developments and innovation in SRC structure depend on not only development of structural design theory, but also improvements of materials and technology. In order to research on basic behaviors and design theory of steel reinforced high strength and high performance concrete (SRHSHPC) beams, the main contents as follows was studied in this paper:1. Firstly, composition materials were analyzed. As an important factor affecting member performance, steel performance that included steel strength and section form were discussed. As the same time, materials-related issues of high strength and high performance concrete (HSHPC) were analyzed specifically, which included preparation objectives and technology route of HSHPC, material microstructure characteristic and interaction, principle of raw material selection, material damage probability, and so on. Through above analysis, preparation method and mixture ratio of HSHPC applied to SRC structures was obtained. Then, relevant properties of HSHPC were tested and material damage constitutive relationship was derived and established.2. Based on experimental study, bonding mechanism and main factors that impact bonding properties between steel and concrete was discussed. The paper points out interface between steel and concrete may become weakness zone and cause different failure modes for structural members. Furthermore, based on bond damage model in SRC structures, damage constitutive relationship of SRC members was derived and established.3. By means of static experiment on SRHSHPC beams, different effect factors on member performance can be completely understood and mastered, which including different concrete strength grade, shear-span ratio, loading modes, steel ratio and shear connection modes on interface between steel and concrete, etc. On the basis of experimental observation, bearing capacity, deformation, failure modes and ductility performance of SRC composite beams were summarized and analyzed.4. According to research status on SRC structures and experimental study, calculations of flexural bearing capacity, calculation of shear-bearing capacity, calculation of rigidity deformation, cracks calculation were analyzed accordingly. At last, formulas were proposed which considered shear performance on shear surface between steel and concrete. On the other hand, constructional requirements were also provided.5. With the aid of finite element analysis software of ANSYS, numerical simulation of SRC beams was finished. By means of rational division and selection for element, finite element systematic analysis method for SRC member has been established.6. By series of theoretical analysis and experimental study, design optimization of SRC beams was analyzed and dual optimization method was proposed which included model optimization and concept optimization.Based on material innovation, testing method innovation and analytical method innovation, systematic analysis method of SRHSHPC beams was established, which took into account material selection, microscopic action mechanism between materials, calculation on bearing capacity, non-linear analysis and optimization of SRC beams, and so on. So it makes full preparations for SRHSHPC structure applications and gives necessary foundation for its development and applications.