Steel plate-concrete composite structure reinforcement method of structural negative moment region

Abstract

A steel plate-concrete composite structure reinforcement method of a structural negative moment region is characterized in that the method comprises the steps of: (1) carrying out interface treatment of a negative moment region of a concrete box girder top plate 3; (2) planting bars on the surface of the negative moment region of the concrete box girder top plate 3; (3) manufacturing a steel plate 9, a welding stud 8 and a corrugated steel plate 14: (4) forming a self-compacting concrete pouring hole 13 and a location leveling hole 17 on the steel plate 9; (5) erecting a reverse ejection support 2 and unloading reverse ejection; (6) binding a reinforcing mesh 10 and installing in position; (7) applying a structural adhesive on the steel plate 9 and spreading fine sands; (8) installing and leveling the steel plate 9 to the design position, applying a pre-stress to the top of the steel plate 9 through a pre-installed apparatus; (9) mixing and pouring self-compacting concrete; and (10) releasing the pre-stress, removing the corrugated steel plate 14, curing concrete, constructing a pavement layer, and removing the reverse ejection support 2. The novel steel plate-concrete composite structure negative moment region reinforcement method can be widely used for negative moment region reinforcement of concrete box girder, T-beam, hollow plate girder, common reinforced concrete beam, and pre-stressed concrete beam, and can be used in the bridge reinforcement with the advantages of almost no reduction of the headroom below the bridge, no requirement for surface levelness of the original structure, low cost, no influences on the appearance, and so on. The steel plate-concrete composite structure reinforcement method is economic, safe, and practical, is easy to ensure the project quality and has wide application prospect.

Description

(1) Technical field [0001] The invention relates to the field of bridge and structural engineering in civil engineering, in particular to a structure reinforcement construction method, in particular to the structure reinforcement construction at the top of a concrete beam. (2) Background technology [0002] Due to natural factors such as explosions, fires, earthquakes, and corrosion of steel bars, as well as human factors such as low design load levels and improper construction, the overall or partial damage of concrete structures has become increasingly serious. Especially for concrete bridges, in recent years, with the development of my country's economy, road load vehicles have become larger and heavier, the traffic flow has increased rapidly, and the traffic density has increased, which has continuously increased the impact force and load fatigue of concrete bridges. , over-limit transportation is particularly serious, and the phenomenon of overloaded bridges operating wi...

AI Technical Summary

Problems solved by technology

Affected by structural form or material properties, these traditional reinforcement methods have certain limitations

[0004] (1) The prestress reinforcement method is limited to improve the shear resistance of the component, and the long-term prestress loss often requires secondary tension, which is difficult to maintain

It is difficult to accurately judge the existing prestress of the old bridge, which will directly affect the newly added prestress. Excessive prestress will cause excessive anti-arch and insufficient local compression bearing capacity, thus limiting the resistance Improved bending capacity

[0005] (2) When adopting the reinforcement method of enlarged section, if the design fails to analyze from the point of view of the overall structure, it is only enlarged for local enlargement, which will cause other parts of the overall structure to form weak layers and cause major damage; The mass and rigidity of the component section will change, and the natural frequency of the structure will also change, which is likely to enter the frequency of earthquake or wind shock and cause resonance phenomenon; Impact

[0006] (3) Although the construction process of the bonded steel reinforcement method is relatively simple, it can improve the bearing capacity of the structure to a certain extent, but it has higher requirements on the smoothness and cleanliness of the surface of the beam body, and the effectiveness of the reinforcement mainly depends on the bonding material. Strength and durability, fatigue resistance is not stable enough

[0007] (4) The improvement of structural rigidity by FRP reinforcement is not obvious, the problems of shear resistance and connection are relatively prominent, and the durability and fire resistance of the bonded surface between FRP material and concrete are poor

After the original bridge is strengthened by composite structure technology, the steel plate also has the same fatigue problem under the action of live load

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