Tesing Research On Mechanic Propertie Of Steel Fiber Reinforced Concrete Corel

For reinforcement concrete corbel with the shear span to depth ratio (a/ho) less than 1, has its performance of mechanics that is close to cantilever deep beams, It is an important kind of components in architectural structure which sustains roof trusses, brackets, tray' beams, frame' beams, wall' beams and crane' beams. Corbels, deep beams and pile caps are included basically in non-flexural elements, the calculative theory of which is relatively complicated, and its calculative method of which is not consistent. For the design of corbel, our national criterion has be ascertained prescribes. The corbel's dimension should be ascertained as the manipulative condition of diagonal section. The amount of longitudinal reinforcement be ascertained on the basis of the flexure model, is obtained according to static for balance condition, the calculative expression of the load is obtained. And in terms of the design method in ultimate state the maximum load. While the amount of stirrup should be defined according to the request of construction details.Steel fiber reinforcement concrete is a new kind of multiple materials that concrete can enhance concrete's strength, ductility and postpone the appearance of cracks when is mixed with steel fiber. Steel fiber scatters stress converging in the area of the top end of tiny cracks, restrict the occurrence and development of cracks, diminishes the width of cracks, and enhances the integrity of concrete with the occurrence of cracks via the effect of felting between concrete and steel fiber, and consequently the strength of concrete that resists compression, tension, and shear force increases obviously, and the capability of concrete that resists compact, and fatigue, and the ductility and durability of fissured concrete improve. Thus the use of steel fiber reinforcement concrete in corbel can avoid complicated calculating in design, and the diminish difficulty of construction, At the same time when corbel's dimension can not be increased the reinforcement concrete corbel's ultimate load capacity and anti-seismic performance can be improved by the addition steel fiber into concrete. This method has become a kind of applied method and is highly concerned by the domestic and international academe and engineer group.Until now, the domestic and overseas scholar has studied the factors that have effect on performance of steel fiber reinforced concrete corbel such as shear span to depth, strength of concrete, reinforcement ratio (including longitudinal reinforcement and stirrup) and ratio of horizontal to vertical load. For calculating the cracking load, and ultimate load domestic and foreign scholar has brought forward a series of calculative formulas and methods have been put forward thatbased on statistical analysis, flexural model and truss model. Relatively speaking overseas study is systemic, but the proposed calculative formulas have too many parameters and are complicated in calculation. And they do not correspond with the domestic calculative system. The domestic study is neither sufficient in depthnor comprehensive. In addition calculative formulas of the ultimate load aim at corbels in flexural. Corbels in shear is rarely studies. There is no relavant content in corbels in Steel fiber reinforced concrete regulations of structural design and construction (CECS38:92). Accordingly the design of steel fiber reinforced corbels does not have any regulations to follow. For the sake of adding design methods of steel fiber reinforced concrete corbels into Technical regulations of steel fiber reinforced concrete, according to the arrangement by the group that edit the regulations, subsidized by The Outstanding Youth Fund of Henan province, carries out the experimental study of 22 steel fiber reinforced concrete corbels. The pressurized behavior of steel fiber reinforced concrete corbels is studies rather systematically, and calculative methods and formulas that adapt for pressurized characteristic of steel fiber reinforced concrete corbels are put forward. The main...