CN103541498A - Steel rib-steel tube fiber concrete combined column - Google Patents

Abstract

The invention relates to a concrete component, in particular to a steel frame-steel tube fiber concrete composite column used in civil engineering. The fiber concrete is located inside and outside the steel pipe, the steel frame is located at the corner of the column, and the concrete contains steel fibers as additives; the length of the steel fibers is 15-60 mm, and the diameter or equivalent diameter is 0.3-1.2 mm. The volume dosage is 0.5% to 3%, generally no more than 3%. The steel tube of the steel frame-steel tube fiber reinforced concrete composite column is wrapped by fiber concrete, and the steel tube can be filled with concrete. The invention is a main component of a building frame structure in a high-rise building, and has the characteristics of high bearing capacity, high rigidity, light weight, good plasticity and toughness, good impact resistance and fatigue resistance, good earthquake resistance and the like.

Description

Steel Reinforced Steel Tube Fiber Concrete Composite Column

technical field

The invention relates to a concrete component, in particular to a steel frame-steel tube fiber reinforced concrete composite column used in civil engineering, and is a new type of steel tube concrete composite column.

Background technique

In "concrete-filled steel tube structure", concrete-filled steel tube columns can be divided into concrete-filled steel tube columns with steel tubes on the outside of the column and concrete-filled steel tube columns with steel tubes inside the column. The former is usually called steel tube concrete column, and the latter is usually called steel tube concrete composite column . Due to the complicated construction of steel tube concrete columns and the need for fireproofing and antirust treatment of steel tubes, steel tube concrete composite columns are mostly used in the construction of high-rise buildings and bridge structures. In composite steel tube concrete columns, the strength grade of the concrete inside the steel tube is usually equal to or higher than the strength grade of the concrete outside the steel tube. Since the steel pipes provide a restraint effect on the concrete in the core area and produce a sleeve effect, the steel pipe concrete composite columns can reduce the plastic displacement of the structure, increase the energy dissipation capacity of the structure, and improve the overall seismic performance of the building. Its research results have been applied to many projects. In Shenyang alone, there are Liaoning Post Hub Building, Shenyang Hepingdi Taxation Bureau Building, Shenyang Hetai Building, etc. However, there are also many disadvantages in the steel tube concrete composite column, such as: 1) When the building has more floors, the load borne by the column will increase, and the section size of the required column will be larger. In order to reduce the section size of the column, this A steel pipe with a thicker wall thickness is required to provide sufficient "sleeve" effect to the concrete, so special processing in the factory is required, which will inevitably increase the project cost, and at the same time it is impossible to realize in the project; 2) For columns with relatively large cross-sectional dimensions, choose large The diameter of the steel pipe can certainly increase the content of the steel pipe. However, this may cause an increase in the amount of steel pipes used, increase the cost of the project, and increase the difficulty of construction, especially the construction of nodes. For example, the cross-sectional size of the composite column of the Liaoning Post Hub Building reaches 950×950 mm, the diameter of the steel pipe reaches 558.8 mm, and the thickness of the pipe wall reaches 12 mm. 3) Since the ductility of CFST composite columns is mainly provided by longitudinal reinforcement, more longitudinal reinforcement is often required, resulting in difficulties in construction. 4) Studies have shown that the inner and outer concrete of this type of column cannot work well together until failure.

Based on the above reasons, the research group has invented patents: steel frame-concrete steel tube column, carbon fiber reinforced plastic steel frame-concrete steel tube composite column, etc., to solve this problem.

Over the years, research on cracks in steel fiber-confined concrete has made significant progress. The conclusion that the cracking strength of steel fiber reinforced concrete is determined by the average spacing of steel fibers that have an effective effect on tensile stress (fiber spacing theory) was proposed, thus starting the practical development stage of this new type of composite material. In recent years, steel fiber has developed rapidly at home and abroad. It overcomes the shortcomings of concrete such as low tensile strength, low ultimate elongation, and brittleness. It has excellent tensile, bending, shearing, crack resistance, fatigue resistance, and high toughness properties. It has been used in construction, roads and bridges, and hydraulic engineering It has been widely used in engineering fields.

According to the material, steel fiber can be divided into ordinary carbon steel fiber and stainless steel fiber, among which the amount of ordinary steel fiber is mostly; according to the shape, it can be divided into long straight shape, indentation shape, wave shape, hook shape, big head shape and twist shape. ;According to the cross-sectional shape, there are circular, rectangular, crescent and irregular shapes; according to the production process, there are cutting type, shearing type, milling type and melting type; according to the construction purpose, there are pouring steel fiber and spraying steel fiber. In order to meet the reinforcement effect and construction performance of steel fibers, the length of steel fibers is usually 15-60mm, the diameter or equivalent diameter is 0.3-1.2mm, the aspect ratio is 30-100, and the volume content of fibers is 0.5%-2 %, generally no more than 3%.

The present invention intends to use the characteristics of fibers to be mixed into concrete, so as to improve the brittleness of the concrete itself, low tensile, shear and flexural strength, and poor bonding performance with steel pipes.

Therefore, the research group imagined that it would be a good way to use fiber as an additive in concrete for construction to form steel-steel fiber reinforced concrete composite columns.

Contents of the invention

The purpose of the present invention is to provide a steel frame-steel tube fiber reinforced concrete composite column, which fully utilizes the properties of the fiber material and improves the crack resistance and strength of the concrete. It is realized through the following technical scheme: it is composed of steel frame, steel tube and fiber concrete, and forms a whole. The steel frame of the steel frame-steel tube fiber concrete composite column is welded by steel plates. The bone is located at the corner of the column. The volume content of fiber is 0.5% to 2%, generally not more than 3%. The length of the steel fiber is 15-60 mm, and the diameter or equivalent diameter is 0.3-1.2 mm. The steel tube of the steel frame-steel tube fiber reinforced concrete composite column is wrapped by fiber concrete, and the steel tube can be filled with concrete.

Advantage and effect of the present invention are:

1. Make full use of the characteristics of fiber materials to improve the disadvantages of high-strength concrete such as brittleness, low tensile, shear and flexural strength;

2. The steel pipe is located inside the intersection of concrete in the vertical and horizontal directions, which can resist fire and corrosion;

3. The steel frame at the corner acts as a constraint on the deformation of the fiber concrete, thereby improving ductility and bearing capacity.

Description of drawings

Figure 1 is a schematic diagram of the cross-section steel-steel fiber reinforced concrete composite column. It is composed of steel skeleton, steel pipe and fiber concrete, in which the fiber concrete is located inside and outside the steel pipe, and the steel skeleton is located at the corner of the column. In the figure, 1 is concrete, 2 is glass concrete, 3 is panel, 4 is steel pipe, and 5 is steel frame.

Detailed ways

It is composed of steel frame, steel pipe and fiber concrete, and forms a whole. The steel frame of the steel frame-steel tube fiber concrete composite column is welded by steel plates. The volume content of fiber is 0.5% to 2%, generally not more than 3%. The length of the steel fiber is 15-60 mm, and the diameter or equivalent diameter is 0.3-1.2 mm. The steel tube of the steel frame-steel tube fiber reinforced concrete composite column is wrapped by fiber concrete, and the steel tube can be filled with concrete.

1. The steel plates are welded into steel frames according to regulations, and the steel frames are connected by patch plates;

2. Stand up the steel pipe and keep it vertical or at a certain angle;

3. Stand up the steel skeleton, and temporarily fix it with the steel pipe, and support the formwork on the outside of the steel skeleton;

4. Make concrete according to the conventional method, and use 5kg-20kg of steel fibers per cubic meter of concrete. The length of the steel fibers is 6-12mm, the diameter is 0.3-1.2mm, and the tensile strength is above 1200MPa. 0.5% to 2%, generally not more than 3%; to make it fully mixed with concrete;

5. Support the formwork on the outer side of the column and pour fiber concrete.

Claims (3)

1. steel frame-steel pipe fibrous concrete coupled column, is comprised of reinforcing bar, steel pipe, fibrous concrete, it is characterized in that: to be wherein positioned at steel pipe inside and outside for fibrous concrete, and reinforcing bar is positioned at the bight of post, contains the steel fibre that serves as additive in its concrete.

2. according to the steel frame-steel pipe fibrous concrete coupled column described in right 1, it is characterized in that: described length of steel fiber is 15～60mm, diameter or equivalent diameter are 0.3～1.2mm, and the volume volume of fiber is 0.5%～3%, is generally no more than 3%.

3. according to the steel frame-steel pipe fibrous concrete coupled column described in right 1, it is characterized in that: the steel pipe of steel frame-steel pipe fibrous concrete coupled column is wrapped up by fibrous concrete, can fill concrete in steel pipe.

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