Method for detecting friction loss and anchoring loss of post-tensioned pre-stressing concrete structure

A concrete structure, post-tensioning prestressing technology, applied in the direction of measuring devices, material inspection products, instruments, etc., can solve the problems of inconvenient construction, labor and time-consuming, unable to measure the friction loss value, etc.

Active Publication Date: 2016-06-08
宁波市镇海垚森土木工程技术服务有限公司
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Problems solved by technology

[0003] Using the method of embedding sensors under the anchor or installing sensors before and after the anchorage to detect the loss of prestress often has the following problems: 1. The sensor method to detect the friction loss of prestress can only be used for prestressed tunnels that are stretched at both ends, and is not applicable Because of the prestressed channel stretched at one end, it is impossible to measure the prestressed friction loss at one end. This is because the sensor method detects the prestressed friction loss. During tensioning construction, a sensor needs to be installed under the anchorage at both ends of the channel. Since the fixed end of one end of tension is poured into the concrete, the sensor cannot be installed during tension, and a sensor can only be installed under the anchorage of the tension end, so that the friction loss

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  • Method for detecting friction loss and anchoring loss of post-tensioned pre-stressing concrete structure
  • Method for detecting friction loss and anchoring loss of post-tensioned pre-stressing concrete structure
  • Method for detecting friction loss and anchoring loss of post-tensioned pre-stressing concrete structure

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Embodiment Construction

[0053] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0054] This part takes a 25.7-meter-span prestressed beam as an example to detect the friction loss and anchorage loss under the tension construction technology at both ends.

[0055] The design parameters of the prestressed beam are as follows:

[0056] ① Bonded prestressed beam, concrete strength C40, reinforcement 2-9Φ s 15.2, using f ptk = 1860MPa low-relaxation steel strands, metal bellows with a wall thickness of not less than 0.3mm, and group anchor systems for anchorage.

[0057] ②The axis span of the prestressed beam is 25.7 meters. At the column, the straight line section at the fixed end is 0.5m, the straight line section at the tension end is 0.3m, the left sagittal height is 1500mm, and the right sagittal height is 1200mm. The tension control stress σ con =0.7f ptk =0.7×1860=1302Mpa, the design overtension coefficient is 3%, a...

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Abstract

The invention discloses a method for detecting the friction loss and anchoring loss of a post-tensioned pre-stressing concrete structure. The method can detect two pre-stress loss indexes such as the friction loss and anchoring loss required by the specification, and can also measure the friction loss of a pre-stress tendon in both a one-end tensioning construction process and a two-end tensioning construction process. The method disclosed by the invention is higher in detection precision and stability, and all the defects of stress loss detection of the conventional sensor method can be overcome; and meanwhile, whole pre-stress construction processes can be effectively detected and monitored. The method can be widely applied to high-intensity materials for pre-stressing, such as non-bonded pre-stressed tendons, retard-bonded pre-stressed tendons, steel bars, steel ropes and carbon fiber bars, so as to detect the friction loss and anchoring loss of the post-tensioned pre-stressing concrete structure of each pre-stressed tendon during pre-stress tensioning construction.

Description

technical field [0001] The invention belongs to the field of construction detection and monitoring during prestressed tensioning construction of post-tensioned prestressed concrete structures in construction engineering, and in particular relates to a detection method for friction loss and anchorage loss of post-tensioned prestressed concrete structures. Background technique [0002] When the post-tensioned prestressed concrete structure is tensioned on site, the prestress loss mainly includes friction loss and anchorage loss. Friction loss refers to the sum of the friction loss at the anchor port at the tension end and the friction loss between the prestress tendon and the tunnel wall when the prestressed tendon is stretched; the anchor loss refers to the deformation and Prestress loss caused by shrinkage of prestressed tendons. At present, the sensor method of installing sensors under the anchorage or before and after the anchorage is often used to detect the friction los...

Claims

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Application Information

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IPC IPC(8): G01N19/00G01N33/38
CPCG01N19/00G01N33/383
Inventor 徐高东薛俏华
Owner 宁波市镇海垚森土木工程技术服务有限公司
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