Device and method for shear reinforcement of concrete box girder web

Abstract

The invention relates to an anti-shearing reinforcement device and method for a concrete box girder web. In order to solve the problem that in existing engineering technologies, the concrete box girder web has cracking inclined cracks and insufficient anti-shearing bearing capacity, an external vertical prestressing tendon reinforcement device and method are provided. The device comprises groove-shaped steel, L-shaped steel, vertical prestressing tendons, wedge-shaped steel cushion blocks and an anti-corrosion coating at the outer side of the web. The groove-shaped steel is horizontally fixedto the junction of the upper end of the web and a top plate in the girder length direction. The L-shaped steel (6) is horizontally fixed to the lower end of the web in the girder length direction andis parallel to the groove-shaped steel (5). The vertical prestressing tendons are vertically mounted on the groove-shaped steel and the L-shaped steel, and it is ensured that the vertical prestressingtendons are parallel to the plane of the web. According to the anti-shearing reinforcement device and method, the web is connected with the top plate and a bottom plate through finish rolling twistedsteel, the force transmission path is definite, the risk that web concrete is pulled broken is reduced, and meanwhile, midspan deformation is reduced; the problem of insufficient main tensile stressof the web concrete is effectively solved, and the situations of continuous extension of the inclined cracks of the web or new inclined cracks are prevented.

Description

Technical field [0001] The invention relates to the technical field of reinforced concrete beam reinforcement. In particular, it relates to reinforcement of oblique cracks and insufficient shear capacity of concrete box girder webs and reinforcement methods. Background technique [0002] Box-section beams are widely used in long-span prestressed concrete bridges because of their good bending and torsion resistance. In recent years, serious web slanted cracks have generally existed in the concrete box girder bridges in operation in my country. Even some box girder bridges have just opened to traffic, and the diagonal cracks in the webs have been very significant. The oblique cracks in the web not only reduce the stiffness and strength of the bridge structure, but also accelerate the corrosion of the steel bars, while the rusted steel bars will cause the volume expansion, the concrete cracking aggravated, and further damage the concrete's mechanical properties, reducing the durab...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to propose external vertical prestressed tendon reinforcement measures for the oblique crack cracking and insufficient shear bearing capacity of the concrete box girder web existing in the existing engineering technology

Effectively solve the problem of excessive main tensile stress of the web

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