Two-way prestressing semicircular steel plate online flawless stabilizing concrete cylinder method

Abstract

Disclosed is a two-way prestressing semicircular steel plate online flawless stabilizing concrete cylinder method. The method comprises the steps that a reinforced section of a reinforced concrete cylinder is sequentially divided into an upper reinforced section, an axial prestressing jacking section and a lower reinforced section from top to bottom; the upper reinforced section and the lower reinforced section are each provided with an annular prestressing reinforcing structure, and annular prestressing reinforcing is applied to the reinforced concrete cylinder; at the axial prestressing jacking section, axial prestress is applied to the annular prestressing reinforcing structures installed on the upper reinforced section and the lower reinforced section through the axial prestressing jacking device. The structure of an existing cylinder is not damaged, online use of the cylinder is not affected, the applied axial prestress and annular prestress are adjustable, and it can be ensured that the existing structure and the reinforcing structure can be synchronously stressed; concrete inside the cylinder is converted by brittle failure into plastic failure, the strength, rigidity and ductility of the reinforced concrete cylinder are obviously improved, and the energy dissipation, seismic resistance and other properties are excellent.

Description

technical field [0001] The invention discloses a method for reinforcing a concrete cylinder, in particular to a method for strengthening a concrete cylinder with bidirectional prestressed semicircular steel plates without damage on-line, and belongs to the technical field of concrete construction methods. Background technique [0002] Reinforced concrete structure is the most widely used structural form in engineering practice. There are many reinforced concrete structures that need to be reinforced due to poor construction quality, changes in building use, structural overloading, exposure to harsh environments, etc. Methods of strengthening reinforced concrete columns include: [0003] Increased section reinforcement method: [0004] Also known as outsourcing concrete reinforcement method, it is a form of reinforcement that increases the cross-section and reinforcement of components or buildings to improve their strength, stiffness, stability and crack resistance to meet ...

AI Technical Summary

Problems solved by technology

The erection of the axial struts shared part of the force of the original concrete columns, so that the original concrete columns were partially unloaded. The existing problem was that the forces of the old and new parts were not synchronized, and the prestressed struts were too long or the force was too large. It is laterally reinforced to ensure its lateral stability

[0018] ②The length of the two semi-circular steel casings is equal to that of the column to be reinforced, and there are difficulties in the fabrication, processing, transportation and on-site installation of the steel casings;

[0020] ④The upper and lower ends of the concrete column are not reinforced, the horizontal shear bearing capacity has not been improved, and the seismic performance of the column and the structural system where it is located has not been significantly improved;

[0022] ⑥There is no reinforcement at the upper and lower ends of the concrete column, its shear bearing capacity has not been improved, and the horizontal shear force distribution of the column and the structural system where it is located has not changed, which is not conducive to the improvement of the overall lateral movement resistance of the structural system

The axial strut shares part of the force of the original concrete column, so that the original concrete column is partially unloaded. The problem is that the force of the old and new parts is not synchronized, and the prestressed strut is too long or the force is too large. Lateral reinforcement is implemented to ensure its lateral stability

The obvious disadvantage of this method is that the prestressed tie rods increase the pressure on the compression part of the concrete column, and the force of the external tie rods and the original tension steel bars in the concrete column are not synchronized, and step failure may occur

[0027] ③Study on the anti-seismic performance of reinforced concrete columns reinforced with low prestressed steel hoops or steel strands. Reinforced concrete columns reinforced with low prestressed steel hoops or steel strands belong to the transverse prestressed reinforcement technology. Steel hoops can effectively restrain the concrete Deformation, the generation and development of restrained cracks, the compressive performance and seismic performance of the column are significantly improved, but the poor force transmission performance at the joint surface will lead to poor overall stress of the reinforced specimen

The first four reinforcement methods mentioned above can reduce the slenderness ratio of the column and increase the rigidity of the column, while the reinforcement of the axial prestressed strut and the reinforcement of the axial prestressed tie rod may reduce the lateral stiffness of the concrete column

⑤The axial strut shares part of the force of the original concrete column, so that the original concrete column is partially unloaded. The existing problem is that the force of the old and new parts is not synchronized. It implements lateral reinforcement to ensure its lateral stability; followed by axial prestressed rod reinforcement

The obvious disadvantage of this method is that the prestressed tie rods increase the pressure on the compression part of the concrete column, and the force of the external tie rods and the original tension steel bars in the concrete column are not synchronized, and step failure may occur

⑥Reinforced concrete columns reinforced with low prestressed steel hoops or steel strands belong to the transverse prestressed reinforcement technology. Steel hoops can effectively restrain the deformation of concrete, restrain the generation and development of cracks, and significantly improve the compressive performance and earthquake resistance of the columns. However, the poor force transmission performance at the joint surface will lead to poor overall stress of the reinforced specimen

⑦ During the stretching process of the rectangular steel hoop plate, there are certain constraints and friction at the corners, and a certain amount of prestress loss (more than 10%) occurs during the transmission of the tension force at the corners; ⑧The combination of the two methods does not overcome Disadvantages of the above-mentioned axial prestressing and transverse prestressing reinforcement

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