Stress applying method and tool thereof for low retraction pre-stress concrete member

A concrete and prestressing technology, which is applied in the direction of manufacturing tools, building structures, ceramic molding machines, etc., can solve the problems of low utilization rate of prestressed tendons and excessive stress application, so as to avoid oblique cracks and reserved grooves in prestressed concrete The effect of reducing the size of the opening and the compact structure of the anchorage at the tension end

CN102912987BInactive Publication Date: 2014-12-24柳州市邱姆预应力机械有限公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2014-12-24
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a stress applying method and a tool thereof for a low retraction pre-stress concrete member, wherein a stretching-drawing anchor of the member is so structured that an anchor plate is installed in a threaded hole of a nut through screw thread; the low retraction pre-stress anchor with the structure secondarily stretches and draws a pre-stressed tendon by using a special stretching-drawing tool, so that a small retraction quantity of the pre-stressed tendon can be obtained; thus, the problems of easy produce of diagonal cracks, great loss of effective and permanent pre-stress of pre-stressed steel strands, low utilization rate of the pre-stressed tendon when a main stretching stress exceeds a limit value which is regulated by the specification in the traditional anchoring process are effectively solved.
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Description

technical field

[0001] The invention relates to the technical field of prestressed concrete component manufacture, in particular to a low-retraction prestressed anchorage including medium and short bundles of prestressed tendons, a stress applying method and a tool. Background technique

[0002] In recent years, with the development of highway and railway construction, prestressed anchors have also been well applied; however, in actual engineering construction, it is difficult to use traditional clip-type anchors for medium and short bundles of prestressed tendons. To meet the requirements of tension control stress, there are problems such as oblique cracks caused by the main tensile stress exceeding the limit specified in the code, large loss of effective permanent prestress, large anchor retraction, and low utilization rate of prestressed tendons. In response to these problems, people put forward the research topic of post-tensioning small tonnage and short prestressed ten...

Examples

Embodiment Construction

[0037] Below in conjunction with accompanying drawing, the present invention is described in further detail:

[0038] figure 1 Shown is the low-retraction prestressed concrete member used in railway bridges and culverts. There is a prefabricated concrete member 1. In the concrete member 1, a bellows 3 for wearing prestressed tendons 2 is embedded in the bellows. 3. There are many prestressed tendons 2 installed in the middle.

[0039] The left end of the concrete member 1 is the fixed anchoring end of the prestressed tendon 2. An anchor pad 25 and a metal spiral bar 5 arranged outside the anchor pad 25 are pre-embedded in the concrete member 1 at this end, and a piece of anchor pad is installed outside the anchor pad. Anchor plate 26, the left end of each prestressed tendon 2 is respectively worn in one of the tapered holes of anchor plate 26, and the tapered surface corresponding to the wall of the tapered hole is formed by the two outer surfaces in the tapered hole. The cl...