Sleeve grouting defect ultrasonic detection device and method based on wavelet packet energy

A technology of sleeve grouting and ultrasonic testing, which is applied to the analysis of solids, materials, and instruments using sound waves/ultrasonic waves/infrasonic waves. It can solve problems such as complex structures, increased concealment of grouting defects, and damage to the integrity of precast concrete components. Low cost and simple structure

Active Publication Date: 2019-04-09
HARBIN INST OF TECH SHENZHEN GRADUATE SCHOOL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Prefabricated concrete components are composed of external reinforced concrete, sleeves and connecting steel bars. The structure is more complex, and the concealment of grouting defects is intensified. It is difficult to effectively identify grouting defects from the traditional single ultrasonic acoustic parameter.
[0005] The prior art discloses a method for detecting the fullness of grouting based on ultrasonic waves on the surface of the sleeve. An ultrasonic transducer with integrated transceiver functions is used for detection, and the strength of the first wave signal received by the ultrasonic transducer is used to judge the fullness of the sleeve. The grouting inside the casing, but the concrete protective layer outside the casing needs to be removed to form an inspection port, which destroys the integrity of the precast concrete components

Method used

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  • Sleeve grouting defect ultrasonic detection device and method based on wavelet packet energy
  • Sleeve grouting defect ultrasonic detection device and method based on wavelet packet energy
  • Sleeve grouting defect ultrasonic detection device and method based on wavelet packet energy

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Embodiment 1

[0068] Embodiment 1 The relevant principle and device explanation of the test method of the present invention

[0069] In this embodiment, the principle of the ultrasonic detection method for steel sleeve grouting connection defects based on wavelet packet energy is as follows.

[0070] According to the characteristics of the ultrasonic detection signal, the wavelet packet analysis decomposes the high-frequency part and low-frequency part of the signal at the same time, adaptively selects the corresponding frequency band to match the signal spectrum, and improves the time-frequency resolution.

[0071] The wavelet packet analysis solves the problem that the frequency resolution is too low when the time resolution of the wavelet analysis is relatively high, and the wavelet packet analysis has more extensive application value.

[0072] Compared with the ultrasonic transmission detection signal of the sleeve grouting dense part, the energy received by the ultrasonic transmission ...

Embodiment 2

[0097] Example 2 The device and method of the present invention based on wavelet packet energy for the ultrasonic detection of sleeve grouting defects are used for the testing of steel sleeve grouting connection defects

[0098] In order to verify the effectiveness of the method of the present invention in detecting the grouting connection defect of the steel bar sleeve, the following test for detecting the grouting defect of the steel bar sleeve test piece was done.

[0099] This test designed 3 types of test specimens and 4 groups of 20 pieces in total: plain concrete + centering sleeve (SJ1 and SJ2), longitudinal reinforcement on both sides + centering sleeve (SJ3) and longitudinal reinforcement on one side + offset sleeve (SJ4 ), and according to the possible existence of steel sleeve grouting connection defects in actual engineering, the sleeve grouting defects are simplified and set as circumferential defects along the connecting steel bars. The size and defect settings ...

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Abstract

The invention provides a sleeve grouting defect ultrasonic detection device and method based on wavelet packet energy. The method comprises the following steps: a wavelet packet energy proportion vector is obtained through an ultrasonic detection signal on a prefabricated concrete member; a sleeve grouting defect index is obtained according to the vector; and a grouting condition of steel bar sleeve grouting connection is judged according to a value of the grouting defect index. According to the method provided by the invention, a defect with a certain size can be detected; the requirements inactual engineering can be met; no special requirements on the prefabricated member exist in the detection process; and damage cannot be caused.

Description

technical field [0001] The invention relates to the field of non-destructive detection of concrete defects, in particular to a device and method for ultrasonic detection of sleeve grouting defects based on wavelet packet energy. Background technique [0002] The widely used connection method of prefabricated concrete structural members is steel sleeve grouting connection. The density of the grouting material in the sleeve has a great influence on the quality of the steel sleeve grouting connection. If the sleeve grouting is not dense, it will seriously affect the reinforced steel bar. The quality of the connection between them leads to the inability of the prefabricated structure to achieve the design goal of "equivalent to cast-in-place", and there are major safety hazards. It is of great practical significance to study the device and method of sleeve grouting defect detection, which can find the grouting defects inside the sleeve in time and deal with them, which will effe...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N29/04
CPCG01N29/04G01N2291/0232
Inventor 李祚华郑立霖郑俊超滕军
Owner HARBIN INST OF TECH SHENZHEN GRADUATE SCHOOL
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