An experimental device for shear strengthening of concrete beams with prestressed frp sheets

Abstract

The invention discloses a prestress FRP sheet shear-resistant reinforced concrete beam experimental device. The prestress FRP sheet shear-resistant reinforced concrete beam experimental device comprises a concrete beam, a stretching-drawing pedestal directly facing one side of a concrete beam web, a steering device arranged on the joint of a concrete beam flange plate and the web, an FRP sheet front end anchoring device arranged at the bottom end of the concrete beam web, an FRP sheet middle steel pressing strip arranged in the middle of the concrete beam web, an FRP sheet rear end anchoring device arranged on the lower side of the outer end of the concrete beam flange plate, a limiting device, a stabilizing device, a jack transversely fixed to the stretching-drawing pedestal, a stretching-drawing end front steel plate, a stretching-drawing end rear steel plate, a screw penetrating through the stretching-drawing end front steel plate and the stretching-drawing end rear steel plate, and an FRP sheet stretching-drawing end clamp arranged on the part, near one end of the concrete beam, of the screw. The limiting device and the stabilizing device are arranged on the side face of the concrete beam web. The stretching-drawing end front steel plate and the stretching-drawing end rear steel plate are located on the two sides of the jack. The prestress FRP sheet shear-resistant reinforced concrete beam experimental device is simple to manufacture, fast and convenient to install and capable of applying prestress to an FRP sheet and then pasting the FRP sheet onto the side face of the concrete beam, and the function of shear-resistant reinforcement is achieved.

Description

technical field [0001] The invention belongs to the fields of civil engineering, construction engineering, highway engineering and municipal engineering, and relates to a prestressed FRP sheet anti-shear reinforcement concrete beam experimental device. Background technique [0002] Prestressed concrete T-section beams (T-beams) and prestressed concrete box-section beams (box girders) are commonly used concrete beams in building structures and bridge structures. In recent years, oblique cracks often appear in the webs of T-beams and box girders in highway bridges due to overloading, natural environment and cracking of material properties, which need to be reinforced. [0003] The traditional strengthening methods of T girder and box girder mainly include enlarging section method, sticking steel plate method, external prestressing method, conversion system method, etc. But above-mentioned reinforcement method has following weak point: 1) can't fast repair damaged concrete bea...

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Problems solved by technology

But above-mentioned reinforcement method has the following deficiencies: 1) can't fast repair damaged concrete beam, as the tension anchorage device of external prestressing method is complicated, and enlarging cross-section method needs planting steel bar, supporting formwork, pouring concrete etc.

2) The steel plate is easy to corrode, which seriously affects the interface bonding performance

3) The self-weight of the concrete beam increases greatly

[0004] Despite the aforementioned advantages, the technology of externally attaching ordinary FRP sheets to strengthen concrete structures still faces some unavoidable important problems in engineering applications: 1) The strength utilization rate of FRP sheets is low; 2) It cannot limit the development of oblique cracks in concrete beams ; 3) The stiffness of the concrete beam cannot be effectively improved, seriously affecting the normal performance of the concrete beam

[0011] To sum up, most of the existing public literatures involve the tensioning and anchoring devices of FRP tendons. FRP tendons and FRP sheets are completely different in geometric configuration, material, physical, mechanical properties, etc., so FRP tendons cannot be directly The tensioning and anchoring device applied to FRP sheet

In addition, there is no experimental device involving the shear strengthening of concrete beams with prestressed FRP sheets

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