Pre-tensioning method broken-line reinforcement idler wheel bending device shaped like Chinese character ''fei''

Abstract

The invention relates to a pre-tensioning method broken-line reinforcement idler wheel bending device shaped like a Chinese character ''fei''. The pre-tensioning method broken-line reinforcement idlerwheel bending device comprises an idler wheel bending device shaped like the Chinese character ''fei'', a mounting base, an anchor bolt and a connecting device connecting the idler wheel bending device shaped like the Chinese character ''fei'' with the mounting base, wherein the idler wheel bending device shaped like the Chinese character ''fei'' comprises a supporting pipe, idler wheels and fixing bolts; the supporting pipe is a round pipe, a base mounting blind hole connected with the upper end of a connecting rod is formed in the bottom of the supporting pipe, and a row of n mounting holesthrough which screws of the fixing bolts penetrate are formed in the upper part of the supporting pipe; and grooves are formed in the middles of the idler wheels, circular holes are formed in the centers of the cross sections of the idler wheels, and idler wheel spacer bushes are installed in the circular holes in a sleeved mode. In the state of installation and use, the screws of the fixing bolts penetrate through the mounting holes in the round pipe, and the idler wheels are installed at the two ends of the screws correspondingly in a sleeving mode. The idler wheels are locked by the head portions of lock nuts and the fixing bolts, and the round pipe and the two rows of idler wheels form a shape like the Chinese character ''fei''. The bending device can avoid the bending point and breaking point effect, protects pre-stressed ribs from being bitten or indented, has convenient construction and good structural mechanical properties, and can prevent the pre-stressed ribs from slipping out.

Description

technical field [0001] The invention relates to an auxiliary device for building construction, in particular to a non-shaped roller bender for pretensioning broken line reinforcement related to prestressed construction. Background technique [0002] One of the key problems in the pretensioning design of broken line reinforcement is the calculation of prestress loss. The broken line bundle is realized by the prestressed tendon bender, which is a key component of the pretensioned broken linear prestressed concrete beam , there are two kinds of conventional benders, pull plate type and roller type: [0003] pull plate bender, such as Figure 20-Figure 21 As shown, holes are generally drilled on the straight plate to fix the prestressed tendons. This kind of bender has a simple structure and low processing and manufacturing costs. However, because the drawing plate is too thick and difficult to process, the thickness of the drawing plate is generally small. As a result, the ben...

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Problems solved by technology

[0003] pull plate bender, such as Figure 20-Figure 21 As shown, holes are generally drilled on the straight plate to fix the prestressed tendons. This kind of bender has a simple structure and low processing and manufacturing costs. However, because the drawing plate is too thick and difficult to process, the thickness of the drawing plate is generally small. As a result, the bending radius is small, and the prestressed tendon is easy to form a "break point" at the starting point, resulting in a reduction in the ultimate tensile strength of the prestressed tendon, a decrease in ductility, and an increase in the friction loss of the prestressed tendon, and it is easy to form a stress concentration phenomenon that affects safety;

[0004] Roller benders, such as Figure 22-Figure 23 As shown, it is different from the pull plate type. The roller bender realizes the bending of the prestressed tendon through the guide roller with a circular cross section. Although this method increases the contact between the prestressed tendon and the guide member under the same conditions The area reduces the stress concentration and inflection point effect at the contact surface, but this kind of bender has a complex structure, many manufacturing processes, and high cost for mass use;

[0005] In addition, the above commonly used pull plates, rollers, and roller benders must pass the prestressed tendons into the holes or between the rollers in a single arrangement, and then cut the prestressed tendons according to the actual application length. Due to the influence of the current beam reinforcement cage , it is usually necessary to use artificial prestressed tendons, which will lead to high labor intensity and reduced construction efficiency, which does not meet the scale requirements of modern mass production

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