Prestressed rib connecting and tensioning device and method

Abstract

The invention discloses a prestressed rib connecting and tensioning device and method. The device integrates connection, tensioning and prestress adjustment of a fractured prestressed rib and is most suitable for connection and prestress tensioning of prestressed ribs in bridge structures, wherein the prestressed ribs are partially fractured due to corrosion. A connecting device is composed of two sleeves and quite simple; a tensioning device is composed of a base, a bevel gear and ratchet assembly, a ratchet cap, a four-way pawl, a stressing rod, a nut, a fan-shaped bevel gear, a transmission ratchet and a two-way pawl. According to the prestressed rib connecting and tensioning device and method, centering connection and prestress tensioning can be conducted on the fractured stressed ribs without a jack, operation is convenient, and the safety is high; the tensioning device needs quite small operation space, can be fully dismantled and reused and is economical and environmentally friendly; prestress loss caused by anchorage deformation does not occur in the tensioning process, the prestress value can be adjusted to be higher or lower, and the precision is quite high; and the prestressed rib connecting and tensioning device can be widely applied to the field of prestressed concrete bridge maintenance and reinforcement.

Description

technical field [0001] The invention relates to a prestressed tendon processing device, in particular to a prestressed tendon connection and stretching device and method for connection and prestressed tensioning of prestressed tendons after partial fracture of prestressed tendons in structures such as bridges due to corrosion and the like. Background technique [0002] For prestressed concrete bridges or structures, local corrosion of prestressed tendons is very easy to occur under adverse environmental effects due to poor construction quality, poor grouting of tunnels, accumulation of rainwater in local locations, and spalling of the concrete protective layer under the impact of vehicles and ships. In addition, due to the material properties of prestressed tendons, and the corrosion forms such as stress corrosion and hydrogen embrittlement under high stress, prestressed tendons are prone to local fracture once they are corroded. When carrying out maintenance and reinforceme...

AI Technical Summary

Problems solved by technology

[0003] At present, there are some disadvantages in the lap-joint connection devices that are mostly used: firstly, it is difficult to ensure the centered connection of the prestressed tendons; secondly, the prestressed tendons are forced to bend at the connection device, which increases the working stress in its local area; thirdly , the lap joint connection device must be prestressed with the help of a hydraulic jack, which requires a large working space, is not easy to operate, and is highly dangerous; in addition, there is a loss of compressive prestress of the anchor similar to that of the short tendon. Its tensile stress is difficult to control accurately

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