Papers by Keyword: Concrete-Filled Steel Tube (CFST)

Abstract: The post-fire axial compressive behavior of a set of steel fiber reinforced ceramsite concrete filled steel tubular short columns (noted as SFCC-SSC) was experimentally studied. Effect of the maximum value of fire response temperatures of the specimens and some parameters on the axial compression performance of the specimens was especially discussed. The results show that the surface of the steel tubes after fire presented dark red for 700°Cof furnace temperature and orange red for 900°C, and there was no obvious descending segment in post-fire load-displacement curves of the most specimens subjected to fire load. It was concluded that the axial bearing capacity of the specimens aftersuffering the furnace temperature of 900°C is much less than that of the specimens not subjected to fire load, and the volume of steel fiber of 0.5% of has the greatest effect on post-fire bearing capacity of specimens of SFCC-SSC.

Abstract: The post-fire behavior of a set of steel fiber reinforced lightweight aggregate concrete filled steel tubular short columns (noted as SFLC-SSC) after exposure to fire was experimentally studied. Effect of the maximum value of fire response temperatures of the tubes and their geometric parameters on the strength and the other mechanical property of the specimens were especially discussed. The experimental results show that the specimens of SFLC-SSC have higher post-fire bearing capacity and better plastic deformation. It was concluded that the maximum response temperature of the specimens has great effect on the post-fire bearing capacity of steel fiber reinforced concrete-filled steel tubes subjected to fire load, and incorporation of 0.5% of volume of steel fiber is best for enhancing the axial compressive bearing capacity of the specimens of SFLC-SSC after exposure to fire.

Abstract: In recent years, Reactive Powder Concrete (RPC) has been concerned by the structural engineers and researchers. RPC is a kind of cement-based composite which has ultra-high strength, high ductility and durability, however, it has great fragility. The fragility performance of RPC will be improved if RPC and steel are put together as RPC-filled steel tube circular stub columns. The aim of this paper is to develop accurate finite element models to simulate the behavior of RPC-filled steel tube circular long columns. The finite element program ABAQUS is used in the analysis. An extensive parametric study is conducted to investigate the effects of different slenderness ratio and confinement action on the strength and behavior of RPC-filled steel tube circular long columns. The results obtained from the models are verified against the results of the tests. The results show that the rising part of load-strain curves are in good agreements with experiment results.

Abstract: Due to the small section dimension, high compressive strength, large stiffness, and excellent deformation capacity, the use of concrete filled steel tube (CFST) piers is attractive, especially to high-pier and super-high-pier bridges located in mountains. This paper reviews available information concerning the application and development of CFST piers. Three bridge examples are then introduced, while the structural design and the construction methods of CFST column piers are described in detail. Furthermore, main parameters of CFST piers, such as slenderness ratio and material strength are concluded. Finally the future research direction of CFST column piers is viewed.

Abstract: The force behavior of outer annular-stiffener type steel castellated beam (OATSCB) - concrete filled steel tube (CFST) is analyzed, and the feasibility of this kind of join is discussed. The loading process of the joint is simulated by using finite element software. By analyzing the hysteretic loops, skeleton curves, energy dissipation coefficient, equivalent viscous damping coefficient and ductility coefficient, the bearing capacity and seismic performance of this type of joint is studied. Before simulation, the validity of the simulation method is verified by using the previous experiment data of outer annular-stiffener type steel beam (OATSB) - CFST. It shows that the results from the finite element simulation method and the experiment are similar to each other, and the hysteretic loops is plump , the energy dissipation coefficient, equivalent viscous damping coefficient and ductility coefficient of this type of joint are high. It can be seen that this type of joint has good mechanical properties, and is easy to realize the yield mechanism of strong column weak beam.

Abstract: A simplified method using an equivalent slenderness ratio was suggested to calculate load-bearing capacity of concrete-filled steel tubular laced column in this paper. The significant differences between compressive and tensile strengths of concrete-filled steel tube were considered. The comparisons between the predicted N_uc and the tested N_ue showed that the predicted method gives generally good predictions of the test results.

Abstract: The construction of integral hoisting of arch rib of concrete filled steel tube arch bridge has the advantages of simple process, easy quality control, small safety risk and not affecting the river navigation, etc. This paper introduces the construction method of arch rib assembly and arch rib large segment hoisting.

Abstract: Bonding quality is the key factor that affects the safety of concrete-filled steel tube (CFST) structure, so it is a very important research that how to judge the bonding quality. This paper expounded the theory of three methods used in nondestructive testing of CFST, and introduced the combined application of the methods of artificial tapping, ultrasonic testing, and strain analysis in a large simulation test.

Abstract: In this paper the concrete-filled steel tube concrete arch bridge as the research object, through the finite element program MIDAS, analyzes the internal force of the whole bridge, determined the distribution of internal force and the most unfavorable position; Using the force balance method, taking the reasonable stress of the bending moment status to control goals, determines the boom of the bridge as the condition of reasonable internal force; Use fall down method, according to the reverse sequence in order to cut the boom, each cut as a model for internal force calculation and analysis, get the next will be cut derrick's internal force, its value is the order construction boom of the initial tension.

Abstract: Steel tube filled with steel high-strength concrete composite column which is made by insert into the I-beam inside the steel tube, and then poured into the high-strength concrete, to form a composite structure. It preserves the advantages of concrete filled steel tube and steel skeleton concrete, and has a higher carrying capacitybetter seismic performance and fire resistance, satisfy the needs of modern engineering structures towards large spanhigh-riseheavy-load and harsh conditions direction development, has broad market prospects. This paper mainly from the work principlemechanical characteristics and current situation of the development the three aspects elaborated the present stage study the significance on the seismic performance of steel tube filled with steel high-strength concrete.