Papers by Keyword: Concrete Filled Steel Tube Column

Abstract: In view of the proposal of embedded steel plate concrete shear wall with concrete filled steel tube columns which contains a new kind shear connector of tie-bars through the circular holes linking concrete layers on both sides of the plate. In order to prove the seismic performance of walls with circular holes on the plate, three steel plate shear wall specimens, including the plate without holes bolted with columns, welded with columns, and the perforated plate welded with columns, were tested under cyclic loading. According to the results, the load-bearing capacity, ductility, energy dissipation, hysteretic behavior and failure phenomena were analyzed. It is showed that the load-bearing capacity of the three specimens were quite close. However, the wall with perforated steel plate has better ductility, energy dissipation and hysteretic behavior. So, it is an effective way to improve the seismic performance of walls by means of embedded perforated steel plate instead of ordinary ones.

Abstract: The shear wall with concrete filled steel tube (CFT) columns and steel plate is a new kind of composite shear wall. In order to know its seismic performance and failure mechanism, six 1/5 scale specimens with the same shear span ratio 1.5, including 3 steel plate shear walls (SPSWs) with CFT columns and 3 reinforced concrete shear walls (RCSWs) with CFT columns and embedded steel plate, were tested under cyclic loading. The thickness of the steel plates in the shear walls changed from 2mm, 4mm to 6mm. Based on the experiment, the load-carrying capacity, hysteresis characteristics, ductility, stiffness degradation, energy dissipation and damage characteristics of the specimens were analyzed. Especially, the ratio of height to sectional thickness of the steel plates in the shear wall was considered. The result shows that both the SPSW with CFT columns and the RCSW with CFT columns and embedded steel plate have good seismic performance and are with important practical engineering value.

Abstract: This paper presents the theoretical and experimental results of concrete-filled steel tube columns subjected to axially compression. A total of 6 specimens with outer square sections reinforced by inner cicular steel tube were constructed for experimental investigation. The ultimate strengths of the columns from tests were obtained. The theoretical strengths of the columns were also investigated based on unified strength theory, and compared with the test results. Good agreement can be observed from the comparison.

Abstract: Reactive Powder Concrete (RPC) is a new kind of building material with high strength and other good performance. The combination of RPC and steel tube will compensate the brittleness of RPC and enhance the stability of steel tube, and the loading capacity of the RPC filled steel tube will be improved. Five RPC filled steel tube columns are designed and tested to obtain the ultimate load bearing capacity, the deformation and the strain information. During the loading process, the concrete and the steel tube of the RPC filled steel tube columns are loaded simultaneously. The loading results show that the deformation of the RPC filled steel tube columns are mainly in elastic phase before the loading capacity is up to the ultimate value. The test load decreases to be 80%~90% of the ultimate loading value and then it changes to be smooth. The failure mode of the RPC filled steel tube columns is ductile. The test loading capacity is compared with the formula from the reference. The tested ultimate load bearing capacity of the steam cured RPC filled steel tube columns is higher than the calculated value. The calculated value is safe for the engineering application. The study is useful for the research and application of RPC filled steel tube column.

Abstract: The test results of six connections under cyclic loading are presented in the paper. Each test specimen was properly designed to model the interior joint of a moment resisting frame, and was identically comprised of three parts that including the circular concrete filled steel tube columns, the reinforced concrete beams, and the short fabricated connection stubs. Energy dissipation was designed to occur in the beams during a severe earthquake. Steel bars which were embedded into concrete core and welded to the connection stubs, were used to transfer the force distributed by the reinforcing bars of concrete beam to the concrete core. The results indicated that the embedded steel bars were very efficient in eliminating the stress concentration on the tube wall and there was no visible deformation occurred on the tube wall until the collapse of the specimen. Furthermore, the connection of each specimen had enough capacity and thus the plastic hinge appeared in the beams. As results, the ductility of this new type structure directly depended on the RC beams.

Abstract: Guangzhou Xita Project uses a special exterior frame which consists of huge inclining concrete-filled columns. To ensure the engineering quality and select the suitable concrete-filled steel tube column structure, two concrete-filled steel tube column structure experiments have been carried out. To ensure the quality of the concrete-filled steel tube column structure experiment, the C100, C90 and C70 high performance concrete experimental research have been done specially, and the result of the experimental researches has been used in concrete-filled steel tube column structure sample successfully. The raw materials, mixture proportions and performance of the high performance concrete were discussed in this paper.