CN108490029B - Method for detecting hollowing of outer wall finish coat - Google Patents

Method for detecting hollowing of outer wall finish coat Download PDF

Info

Publication number
CN108490029B
CN108490029B CN201810229483.0A CN201810229483A CN108490029B CN 108490029 B CN108490029 B CN 108490029B CN 201810229483 A CN201810229483 A CN 201810229483A CN 108490029 B CN108490029 B CN 108490029B
Authority
CN
China
Prior art keywords
image
temperature
suspicious
defect
infrared
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201810229483.0A
Other languages
Chinese (zh)
Other versions
CN108490029A (en
Inventor
王宗山
翟志强
端木琳
邵正建
乐思扬
黄茂荃
方天姿
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dalian University of Technology
Original Assignee
Dalian University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dalian University of Technology filed Critical Dalian University of Technology
Priority to CN201810229483.0A priority Critical patent/CN108490029B/en
Publication of CN108490029A publication Critical patent/CN108490029A/en
Application granted granted Critical
Publication of CN108490029B publication Critical patent/CN108490029B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00Investigating or analyzing materials by the use of thermal means
    • G01N25/72Investigating presence of flaws

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)

Abstract

The invention belongs to the technical field of building engineering safety detection, and provides a method for detecting hollowing of an outer wall finish coat. (1) A method for finding suspicious positions with defects by using infrared temperature gradient images. (2) And in the case of poor detection conditions, an auxiliary technical means of heating the surface by laser irradiation is adopted, and the surface temperature difference is amplified to detect the defects. (3) And for the suspicious regions with abnormal temperature, identifying and judging whether the facing layer hollowing defects exist or not by utilizing temperature difference change comparison in the temperature rising and reducing processes. The method for detecting the defects of the veneer layer of the facade of the building can realize remote detection in the actual detection operation, avoid high-altitude dangerous operation of personnel and has simple and convenient operation. The subjectivity and instability brought by artificial temperature image color identification can be overcome in the aspect of data analysis processing, and batch processing of image analysis or real-time detection and analysis can be realized through software.

Description

Method for detecting hollowing of outer wall finish coat
Technical Field
The invention belongs to the technical field of building engineering safety detection, and relates to a technical means of wall quality detection, in particular to a field detection method for detecting whether hollowing potential safety hazards exist on a decorative surface layer of an outer vertical surface of a building, such as a ceramic tile and the like.
Background
The sticking of the exterior wall facing brick is a common exterior wall decoration form in the high-rise buildings of the city at present, and is widely used with the advantages of beauty, economy and the like, but the hollow bulge can be formed and fall off to bring potential safety hazards. The main problem is that the bonding strength between the facing layer and the concrete or brick wall base layer is gradually reduced along with the time due to the fact that the construction quality does not reach the standard or the construction quality is aged for a long time, and when the bonding strength does not meet the requirement, the facing layer can be partially separated from the base layer to form hollowing; if the reinforcement is not carried out, the hollowing area can be gradually increased, and finally, the decorative layer is completely separated from the base layer, and accidents such as high falling are caused. Due to the large detection area, the requirement on detecting defects is fine, and the high-altitude operation of the outer vertical surface is limited, a detection means which can quickly diagnose and generally check the defects of the decorative surface layer of the outer vertical surface of the building is needed.
At present, the defects of the outer wall veneer of the building are mainly detected by a knocking method, a drawing method and an infrared thermal imaging method, and although the knocking method and the drawing method have accurate detection results, high-altitude operation is required for the outer vertical surface of the high-rise building, the detection time is long, the efficiency is low, and the detection is greatly influenced by the subjective judgment of detection personnel; compared with other methods, the infrared imaging method has the characteristics of high efficiency, intuition, rapidness, low manpower and material cost and the like, has obvious advantages in the application of hollowing of the facing bricks of the general investigation exterior walls, and related detection regulations and standards are promulgated by related departments, but the existing infrared method is limited in the actual detection application process, and has the following main problems:
1. when the hollowing of the exterior wall facing brick is detected by an infrared method, the detection result which is judged by simply depending on the color difference of the shot infrared image is easily influenced by meteorological conditions, particularly solar radiation, so that the restriction of the detection condition is formed.
Under the irradiation of stronger solar radiation intensity, the temperature difference between the hollow area and the normal area on the surface of the outer wall continuously changes along with time, and only the proper detection time interval of part of cities in the whole country is regulated in technical regulation for detecting the bonding quality of the outer wall facing of the building by infrared thermography (JGJ/T277-2012), but the rule of universality is lacked. Chinese patent No. 201610523425.X (an infrared quality detection method for hollowing defects of an external wall) proposes a method for reducing the temperature of a whole wall surface by spraying a cooling liquid after irradiation of sunlight to reduce detection errors. Although feasible, the temperature of the outer wall surface needs to be reduced for 5-15 minutes, and the spraying is uniform, so that the operation difficulty and the cost are relatively high in the actual implementation process.
When the meteorological conditions are not good (such as cloudy days and heavy fog), the temperature difference of the wall surface is very small, and particularly, the detection effect of the infrared thermal imager on the north outer vertical surface is greatly reduced; the Chinese patent with the application number of 200810207217.4 discloses a non-contact nondestructive testing method for detecting the hollowing position of ancient murals, the surface of an outer wall is heated through a bulb, and a thermograph is obtained through infrared thermal imaging, so that the area with unobvious heat rise is judged to be a hollowing area. Although the direction can be used for detecting the hollowing of the outer wall, the detection efficiency of the hollowing of the outer wall is improved, detection conditions such as power supply and distribution are needed when the bulb is reheated, the detection conditions are complex, the temperature rise amplitude of the surface of the outer wall is very small, heating is uneven, and the effect is not obvious.
2. The existing technical means is that the color difference of the detected infrared image caused by the temperature difference is used for judging the defect position, the common problem exists all the time is that the color difference has a great relationship with factors such as the value range of the color development temperature selected in the later image processing process, manual setting and adjustment are needed, the labor cost and the time consumption are greatly increased for the whole general investigation of the building outer wall, the efficiency is low, the subjectivity in the identification process can be overcome by using an analysis method of batch processing calculation by using a computer, and the reliability of detection and identification is improved.
3. When the hollowing of the exterior wall facing brick is detected by an infrared method, the radiation of the surrounding environment, the emissivity of the outer surface of the wall surface, the surface color and the shooting angle can have great influence on the detection result, and a temperature abnormal area which is not caused by the hollowing can appear on an infrared picture, so that the higher misjudgment rate exists only by depending on the comparison of an infrared thermal image and a visible light picture, the bonding defect of the facing layer cannot be fully determined, and other auxiliary detection methods such as a hammering method, a drawing method and the like are also needed to carry out necessary verification.
Disclosure of Invention
The purpose of the invention is:
(1) a method for finding suspicious positions with defects by using infrared temperature gradient images.
Because the temperature testing precision of the infrared camera is not high, but the temperature resolution ratio can reach more than 50mK, the invention provides a method for converting an original infrared temperature image into a temperature gradient image through data processing, the temperature on the boundary of a normal area and an abnormal area obviously steps, the temperature gradient of the position is obviously higher than the gradient in the area, the gradient image is filtered, and the texture contour is filtered by combining with a visible light contour line comparison method, and the position and the contour of the area which possibly have defects can be identified through further processing.
(2) And in the case of poor detection conditions, particularly in the case of an unsatisfactory north facade or unsatisfactory solar radiation intensity, an auxiliary technical means of heating the surface by laser irradiation is adopted to amplify the surface temperature difference for defect detection. The auxiliary means realizes non-contact detection by utilizing the remote transmission characteristic of the laser beam, has rapid heating, uniform heating quantity, controllable adjustment and accuracy, and can identify and judge the hollowing by utilizing the relationship between the temperature rise condition after irradiation and the radiation quantity.
(3) And for the suspicious regions with abnormal temperature, identifying and judging whether the facing layer hollowing defects exist or not by utilizing temperature difference change comparison in the temperature rising and reducing processes.
Due to the existence of the decorative surface layer hollowing area, the surface of the hollowing is quickly heated to form hot spots during heating, the surface of the hollowing is quickly cooled to form cold spots during cooling, the change characteristic that positive and negative reversal can occur due to the temperature difference between the defective position of the hollowing and the normal surface is utilized, the influence of other factors such as surface emissivity and wall material is eliminated, and then whether the hollowing exists is determined. The technical means improves the accuracy and reliability of the traditional infrared detection method, avoids high-altitude operation danger caused by contact detection compared with a tapping method and a drawing method, and has high detection efficiency.
The technical scheme of the invention is as follows:
a method for detecting hollowing of an outer wall finish coat comprises the following steps:
(1) when the outer wall to be detected is in a good solar irradiation condition, performing infrared temperature image test on the outer facade of the building in a surface heating stage, acquiring an original visible light image and an original infrared image, and recording the number of each image, corresponding shooting position information and solar radiation intensity information;
according to the shooting angle, referring to the identification point of the visible light image, carrying out image shaping calibration on the original visible light image and the infrared image, wherein the calibration is a plane image which is just opposite to the shooting;
(2) converting the infrared image obtained by the last step of processing into a temperature gradient image, adjusting and filtering according to the test condition, removing the influence of the surface texture of the temperature gradient image to obtain a profile map of the surface temperature abnormal region, comparing the profile map with the profile of the original visible light image, and further identifying the outline of the original block of the facade from the infrared image, wherein the remaining other outline closed regions are represented as defect suspicious blocks;
(3) screening out images with defect suspicious blocks, marking suspicious contour lines corresponding to the obtained defect suspicious blocks on the infrared images and the original visible light images, and respectively calculating the areas and the average temperatures of the defect suspicious blocks and the surrounding blocks;
(4) according to the serial number of the recorded image, shooting position information and a defect suspicious area marked on the original visible light image, positioning the suspicious defect part of the building; carrying out secondary examination on the suspicious defect part in a cooling time period, and repeating the operations of the steps (1) to (3);
summarizing each suspicious defect part and surrounding areas, measuring the average temperature of detection for multiple times, calculating the temperature difference, and judging that the suspicious defect part has the empty drum defect if the temperature difference is found to have obvious positive and negative alternation phenomena.
The invention has the beneficial effects that: the method for detecting the defects of the veneer layer of the facade of the building can realize remote detection in the actual detection operation, avoid high-altitude dangerous operation of personnel and has simple and convenient operation. In the aspect of data analysis and processing, the subjectivity and instability caused by artificial temperature image color identification can be overcome, and batch processing of image analysis or real-time detection and analysis can be realized through software.
Detailed Description
The following further describes the specific embodiments of the present invention in combination with the technical solutions.
Examples
The method for detecting the hollowing of the outer wall finish coat comprises the following steps:
(1) when the outer wall to be detected is in a good solar irradiation condition, performing infrared temperature image test on the outer facade of the building in a surface heating stage, acquiring an original visible light image and an original infrared image, and recording the number of each image, corresponding shooting position information and solar radiation intensity information;
according to the shooting angle, referring to the identification point of the visible light image, carrying out image shaping calibration on the original visible light image and the infrared image, wherein the calibration is a plane image which is just opposite to the shooting;
(2) converting the infrared image obtained by the last step of processing into a temperature gradient image, adjusting and filtering according to the test condition, removing the influence of the surface texture of the temperature gradient image to obtain a profile map of the surface temperature abnormal region, comparing the profile map with the profile of the original visible light image, and further identifying the outline of the original block of the facade from the infrared image, wherein the remaining other outline closed regions are represented as defect suspicious blocks;
(3) screening out images with defect suspicious blocks, marking suspicious contour lines corresponding to the obtained defect suspicious blocks on the infrared images and the original visible light images, and respectively calculating the areas and the average temperatures of the defect suspicious blocks and the surrounding blocks;
(4) according to the serial number of the recorded image, shooting position information and a defect suspicious area marked on the original visible light image, positioning the suspicious defect part of the building; carrying out secondary examination on the suspicious defect part in a cooling time period, and repeating the operations of the steps (1) to (3);
summarizing each suspicious defect part and surrounding areas, measuring the average temperature of detection for multiple times, calculating the temperature difference, and judging that the suspicious defect part has the empty drum defect if the temperature difference is found to have obvious positive and negative alternation phenomena.
In the required detection time, under the conditions that weather conditions are not good and surface temperatures are not obviously different, a laser surface light source is used for irradiating the outer wall to be detected for 2-5 minutes, an infrared camera is used for tracking and recording the overall change conditions of temperature rise and recovery of an irradiated area, whether an abnormal temperature area exists in the area or not is observed, if an abnormal area exists, an area surface with an obvious phenomenon is selected, image analysis processing is carried out through the steps (1) to (3), and a temperature change curve of the abnormal area and the surrounding area is drawn; and (4) performing heat transfer calculation on the outer surface of the building by using the laser emission power of the surface light source, and if the calculation result is consistent with the actual test, judging that the area is the empty drum defect position.

Claims (2)

1. A method for detecting hollowing of an outer wall finish coat is characterized by comprising the following steps:
(1) when the outer wall to be detected is in a good solar irradiation condition, performing infrared temperature image test on the outer facade of the building in a surface heating stage, acquiring an original visible light image and an original infrared image, and recording the number of each image, corresponding shooting position information and solar radiation intensity information;
according to the shooting angle, referring to the identification point of the visible light image, carrying out image shaping calibration on the original visible light image and the infrared image, wherein the calibration is a plane image which is just opposite to the shooting;
(2) converting the infrared image obtained by the last step of processing into a temperature gradient image, adjusting and filtering according to the test condition, removing the influence of the surface texture of the temperature gradient image to obtain a profile map of the surface temperature abnormal region, comparing the profile map with the profile of the original visible light image, and further identifying the outline of the original block of the facade from the infrared image, wherein the remaining other outline closed regions are represented as defect suspicious blocks;
(3) screening out images with defect suspicious blocks, marking suspicious contour lines corresponding to the obtained defect suspicious blocks on the infrared images and the original visible light images, and respectively calculating the areas and the average temperatures of the defect suspicious blocks and the surrounding blocks;
(4) according to the serial number of the recorded image, shooting position information and a defect suspicious area marked on the original visible light image, positioning the suspicious defect part of the building; carrying out secondary examination on the suspicious defect part in a cooling time period, and repeating the operations of the steps (1) to (3);
summarizing each suspicious defect part and surrounding areas, measuring the average temperature of detection for multiple times, calculating the temperature difference, and judging that the suspicious defect part has the empty drum defect if the temperature difference is found to have obvious positive and negative alternation phenomena.
2. The method for detecting the hollowing of the outer wall finish coat according to claim 1, characterized in that under the conditions of bad weather conditions and no obvious difference in surface temperature within the required detection time, a laser surface light source is utilized to irradiate the outer wall to be detected for 2-5 minutes, an infrared camera is utilized to track and record the overall change condition of temperature rise and recovery of an irradiated area, whether a temperature abnormal area exists in the area is observed, if an abnormal area exists, an area surface with obvious phenomenon is selected, image analysis processing is carried out through the steps (1) - (3), and a temperature change curve of the abnormal area and the surrounding area is drawn; and (4) performing heat transfer calculation on the outer surface of the building by using the laser emission power of the surface light source, and if the calculation result is consistent with the actual test, judging that the area is the empty drum defect position.
CN201810229483.0A 2018-03-13 2018-03-13 Method for detecting hollowing of outer wall finish coat Active CN108490029B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810229483.0A CN108490029B (en) 2018-03-13 2018-03-13 Method for detecting hollowing of outer wall finish coat

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810229483.0A CN108490029B (en) 2018-03-13 2018-03-13 Method for detecting hollowing of outer wall finish coat

Publications (2)

Publication Number Publication Date
CN108490029A CN108490029A (en) 2018-09-04
CN108490029B true CN108490029B (en) 2020-08-14

Family

ID=63318633

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810229483.0A Active CN108490029B (en) 2018-03-13 2018-03-13 Method for detecting hollowing of outer wall finish coat

Country Status (1)

Country Link
CN (1) CN108490029B (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110542688A (en) * 2019-09-24 2019-12-06 南京工大建设工程技术有限公司 Method for monitoring furnace temperature and defects in fire resistance test process of building component in real time
CN110987992A (en) * 2020-01-02 2020-04-10 上海市建筑科学研究院有限公司 Back-scattering imaging-based quantitative identification method for internal defects of external thermal insulation system of external wall
CN111366602A (en) * 2020-03-19 2020-07-03 三一筑工科技有限公司 Method, device and system for detecting compactness of concrete in prefabricated cavity wall
CN111711765A (en) * 2020-05-29 2020-09-25 杭州电子科技大学 Part production process inspection system
JPWO2022091702A1 (en) * 2020-10-30 2022-05-05
CN112927214A (en) * 2021-03-12 2021-06-08 深圳信息职业技术学院 Building defect positioning method, system and storage medium
CN113588783A (en) * 2021-07-07 2021-11-02 宁波和邦检测研究有限公司 Cement mortar hollowing detection method and system, storage medium and intelligent terminal
CN115598178B (en) * 2022-12-14 2023-05-05 天津思睿信息技术有限公司 Infrared detection method and system for building wall hollowing defect
CN117169477B (en) * 2023-10-25 2024-01-12 广东省装饰有限公司 Building indoor ground hollowing degree assessment method

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06201625A (en) * 1992-10-26 1994-07-22 Puranetsuto Kk Apparatus and method for searching defect
JP2002257761A (en) * 2000-12-25 2002-09-11 Sekisui Chem Co Ltd Probing method for defect of outside wall material, repairing method for outside wall material, and coating material for surface finishing of outside wall material
CN101451970A (en) * 2008-12-18 2009-06-10 上海交通大学 Non-contact nondestructive detecting method for hollow drum position of ancient mural painting
CN103195217A (en) * 2013-04-23 2013-07-10 山东建筑大学 Adhering outer wall outer heat insulating system energy-saving reconstruction base layer processing method for existing buildings
CN203310787U (en) * 2013-06-28 2013-11-27 江苏易可纺家纺有限公司 Heat insulation cloth testing platform
CN205449851U (en) * 2015-12-22 2016-08-10 徐州市宏达土木工程试验室有限责任公司 Infrared thermal imagery detecting system of building door and window and wall body combination defect
CN105866174A (en) * 2016-03-22 2016-08-17 中国矿业大学(北京) Method and system for determining infrared thermographic detection occasion of bonding defect of exterior-wall facing brick
CN106018420A (en) * 2016-07-05 2016-10-12 江苏方建质量鉴定检测有限公司 Infrared quality detecting method for hollowing defects of outer wall

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06201625A (en) * 1992-10-26 1994-07-22 Puranetsuto Kk Apparatus and method for searching defect
JP2002257761A (en) * 2000-12-25 2002-09-11 Sekisui Chem Co Ltd Probing method for defect of outside wall material, repairing method for outside wall material, and coating material for surface finishing of outside wall material
CN101451970A (en) * 2008-12-18 2009-06-10 上海交通大学 Non-contact nondestructive detecting method for hollow drum position of ancient mural painting
CN103195217A (en) * 2013-04-23 2013-07-10 山东建筑大学 Adhering outer wall outer heat insulating system energy-saving reconstruction base layer processing method for existing buildings
CN203310787U (en) * 2013-06-28 2013-11-27 江苏易可纺家纺有限公司 Heat insulation cloth testing platform
CN205449851U (en) * 2015-12-22 2016-08-10 徐州市宏达土木工程试验室有限责任公司 Infrared thermal imagery detecting system of building door and window and wall body combination defect
CN105866174A (en) * 2016-03-22 2016-08-17 中国矿业大学(北京) Method and system for determining infrared thermographic detection occasion of bonding defect of exterior-wall facing brick
CN106018420A (en) * 2016-07-05 2016-10-12 江苏方建质量鉴定检测有限公司 Infrared quality detecting method for hollowing defects of outer wall

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Evaluation of building materials using infrared thermography;E.Barreira,V.P.de Freitas;《Construction and Building Materials》;20050824;第218-224页 *
红外图像处理在墙体空鼓检测上的应用研究;田旭园 等;《计算机测量与控制》;20121231;第20卷(第6期);第1501-1503页 *
红外热像法检测建筑外墙饰面粘结质量技术研究;赵锐;《工程设计施工与管理》;20171031(第19期);第89-92页 *

Also Published As

Publication number Publication date
CN108490029A (en) 2018-09-04

Similar Documents

Publication Publication Date Title
CN108490029B (en) Method for detecting hollowing of outer wall finish coat
US11367171B2 (en) Method for detecting hollowing of exterior wall finish layer
CN107389688B (en) Multi-station integrated repairing method for micro-defects on surface of large-caliber fused quartz optical element
US20070051891A1 (en) Systems and methods for inspecting coatings
CN105095608B (en) A kind of test method of satellite stray light
CN101806762A (en) Method for identifying thermal defects by means of auxiliary heat source under condition of small temperature difference
CN104458765A (en) Infrared thermography detecting system for magnetic shoe defects and detecting method of system
CN106018420B (en) A kind of infrared quality determining method of sloughing of exterior wall defect
CN115144434A (en) Method for detecting defects of building outer wall by using infrared thermal imaging technology
US20110189379A1 (en) Method for the thermographic inspection of nonmetallic materials, particularly coated nonmetallic materials, as well as method for the production thereof and an object produced according to the method
CN103195217B (en) Adhering outer wall outer heat insulating system energy-saving reconstruction base layer processing method for existing buildings
JPS5952735A (en) Surface flaw detecting method of hot billet
CN105758208B (en) High-temperature heat treatment non-contact temperature uniformity detection system and its detection method
CN112557403A (en) Automatic detection device and method for hollowing rate of ceramic tile
Garbacz et al. Inspection method of aluminium extrusion process
CN104299926A (en) Inspection method and apparatus of crystallized silicon
KR102296844B1 (en) Tile backfill estimation method based on measurement and analysis of thermal image
CN114354689A (en) Method for measuring defect depth of sample by square wave excitation infrared thermal wave imaging
Jianmin et al. Design of on-line detection system for apple early bruise based on thermal properties analysis
CN201653955U (en) Auxiliary heating source for recognizing thermotechnical defects inside walls under small temperature difference
CN214201217U (en) Automatic detection device for hollowing rate of ceramic tile
Tomić et al. Aluminium tiles defects detection by employing pulsed thermography method with diferent thermal cameras
Proszak-Miąsik Use of thermal imaging in construction
Denton et al. Determination of threshold average temperature for cell death in an in vitro retinal model using thermography
Wang et al. Experimental study on aerial detection of concrete microcracks based on fluorescent selective excitation

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant