Experimental Research On The Properties Of Steel Pipe Concrete Column And Girderless Floor

The girderless floor system refers to the structure form where the floorstab is sustained directly on the column with no ribbon strip inserted in the floor. With the characteristic of small sectional dimension and high bearing capacity, the steel pipe concrete column has replaced the concrete column used in mushroom construction, thus creating a new structure: The structure of steel pipe concrete column and girderless floor, which is characterized as flexible layout and large activity space, the effective control and guarantee of column cross-section and intensity and convenient execution. As present simplified method solves the problem of reinforcing bars computation of this kind of floor with difficulty, it is necessary to carry out a deep research into it.In the concrete research process, the comparison of distributed steel calculation is conducted through the direct design method from the U.S., the empirical coefficient method from China and finite element method of PKPM, after which the relatively rational method of PKPM is chosen to carry out the comparison of distributed steel calculation. Made the test model of steel pipe concrete column and girderless floor was given an experimental research on vertical uniform load and horizontal load, from the result of which slap steel bar strain load curve and deflection load curve are obtained under vertical uniform load and later the survey of fissure development under horizontal uniform load, the load-displacement curve of actuators, the displacement temporal curve and the strain temporal curve of the structure is completed.It is found in this research that the fact that there is no crack of girderless floor under 2 times design load of the vertical uniform load has demonstrated that the actual slab of vertical bearing capacity larger than the design value. After analysis, the reason possibly is the span small floor its support's restraint, the thickness of slab value as well as arches the effect and so on to be bigger to the supporting capacity influence general span floor, waits for further studying. The floor uctility factor of the test model under horizontal load is 3.32 and the limited value of the elastic interformational displacement angle is not smaller than 1.75%, meeting the needs of what is stipulated in《The designing Regulations of Architecture Earthquake-Resistance》(GB50011-2001) of China. The steel pipe concrete column's rigidity is small, and its lateral deformation ability is obviously good in the ordinary reinforced concrete column. Therefore the sideway capacity of steel pipe concrete column and girderless floor is similar to that of skeleton structure and better than that of ordinary girderless floor. The experimental analysis indicated that restraint function of the panel point of steel pipe concrete column is situated between the fixed restraint function (21.0%, 28.0%), so the panel point of steel pipe concrete column has a good capacity to vary and extend, making its capacity to vary better than that of ordinary steel pipe concrete column.