Experimental Research Of Steel Fiber Reinforced Cement Based Composites Special-shaped Columns Under Axial Force

As the urban population increase rapidly after the reform and open policy, in order to improve the utilization of land, high-rise buildings and super high-rise buildings springing up, such as the Shanghai world financial center, Hong Kong and Wenzhou world trade center building, and a series of well-known super-tall building. Building floors increases necessary to increase the load-bearing column section size and improve the concrete strength grade. The increase of the load-bearing column section size can reduce the effective use of building area, at the same time with the increase of concrete strength grade and lead to the seismic resistance of buildings. In order to improve the structure of the seismic ability, steel-fiber cement based composite material can be used to replace the traditional concrete. At the same time in order to improve the effective use of the area of the building for indoor furniture put, cross column can be used in place of the traditional square column. So this article puts forward using high-strength stirrup restraint steel-fiber cement based composite materials profiled column in order to improve the ductility of structure and increase the effective use of the area of the building.In this paper, a total of 12 different column specimen was designed, in one of the three specimens without adding steel fiber, three specimens with steel fiber volume fraction is 1%, the remaining six specimens with steel fiber volume fraction is 2%. Through analyzing the axial compression test specimens, the high-strength stirrup spacing, steel fiber content and strength grade of cement based composite material with high-strength stirrup constraints of steel-fiber cement based composites shaped column bearing capacity and deformation properties of the specimens, the influence of stirrup characteristic value of the specimens was analyzed, the influence of the bearing capacity of specimens.High-strength stirrup constraints of steel fiber cement-based composite materials different columns axial compression test showed that steel fiber can effectively improve the deformation performance of cement-based composite materials, thus improve the peak strain and deformation capacity of column. By analyzing the experimental data and organizing a large number of references, the constraint intensity formula of steel fiber cement-based composites,bearing capacity formula of the deformed column, column formula of peak stress, peak strain of the deformed column formula as well as to the special column under the condition of axial compression stress-strain curve model were theoretically proved.