阅读说明：本技术 一种基于红外线成像原理检测装配式混凝土灌浆套筒钢筋锚固长度的方法 (Method for detecting steel bar anchoring length of assembled concrete grouting sleeve based on infrared imaging principle ) 是由 周旭东 许守杰 甘绪超 芮志军 于 2020-05-22 设计创作，主要内容包括：本发明公开了一种基于红外线成像原理检测装配式混凝土灌浆套筒钢筋锚固长度的方法,包括以下步骤:采用灌浆套筒连接待检测预制构件,凿开待检验钢筋周边座浆层,将插入灌浆套筒的钢筋裸露出一部分；在钢筋裸露部分安装电磁加热设备和红外热成像仪,采用电磁加热设备对裸露的钢筋进行局部加热；局部加热的钢筋将热量传递到灌浆料,灌浆料将热量传递到混凝土预制构件表面；红外热成像仪对预制构件表面进行检测,形成红外热像图,通过红外热像图上颜色的不同来判断钢筋的锚固长度。成像效果好,能清晰的观察到灌浆套筒内钢筋的锚固长度,满足对套筒施工质量的判别要求。(The invention discloses a method for detecting the anchoring length of a steel bar of an assembled concrete grouting sleeve based on an infrared imaging principle, which comprises the following steps of connecting a prefabricated part to be detected by using the grouting sleeve, chiseling a seat grout layer on the periphery of the steel bar to be detected, and exposing a part of the steel bar inserted into the grouting sleeve; installing electromagnetic heating equipment and an infrared thermal imager on the exposed part of the steel bar, and locally heating the exposed steel bar by adopting the electromagnetic heating equipment; the locally heated steel bars transmit heat to the grouting material, and the grouting material transmits the heat to the surface of the concrete prefabricated part; the infrared thermal imager detects the prefabricated component surface, forms the infrared thermal image, judges the anchor length of reinforcing bar through the difference of the colour on the infrared thermal image. The imaging effect is good, the anchoring length of the steel bar in the grouting sleeve can be clearly observed, and the judgment requirement on the construction quality of the sleeve is met.)

1. A method for detecting the anchoring length of a steel bar of an assembled concrete grouting sleeve based on an infrared imaging principle comprises the following steps:

step (3), connecting the prefabricated part (1) to be detected by adopting a grouting sleeve (2), chiseling a seat grouting layer (3) on the periphery of the steel bar to be detected, and exposing a part of the steel bar inserted into the grouting sleeve;

step (2), installing electromagnetic heating equipment and an infrared thermal imager on the exposed part of the steel bar, and locally heating the exposed steel bar by adopting the electromagnetic heating equipment; the locally heated steel bars transmit heat to the grouting material, and the grouting material transmits the heat to the surface of the concrete prefabricated part (1);

and (3) detecting the surface of the prefabricated part by an infrared thermal imager to form an infrared thermal image, and judging the anchoring length of the steel bar according to the difference of colors on the infrared thermal image.

2. The method for detecting the anchoring length of the steel bar of the fabricated concrete grouting sleeve based on the infrared imaging principle as claimed in claim 1, wherein in the step (1), the exposed length of the steel bar is within 3 cm.

3. The method for detecting the steel bar anchoring length of the fabricated concrete grouting sleeve based on the infrared ray imaging principle as claimed in claim 1, wherein in the step (2), the electromagnetic heating device is composed of an electromagnetic heating controller and an electromagnetic heating coil.

4. The method for detecting the anchoring length of the steel bar of the fabricated concrete grouting sleeve based on the infrared ray imaging principle as claimed in claim 1, wherein the step (3) of determining the anchoring length of the steel bar through the difference of colors on the image is to determine the amount of heat obtained by the prefabricated part through the colors of the infrared thermography image, and the region is reddish in color, which is the anchoring length of the steel bar, the higher the amount of heat obtained by conduction.

Technical Field

The invention relates to a method for detecting the anchoring length of a sleeve steel bar of an assembled concrete structure, in particular to a method for realizing the detection of the anchoring length of the sleeve steel bar of an assembled concrete grouting sleeve based on an infrared imaging principle.

Background

The prefabricated concrete structure is a concrete structure formed by assembling and connecting prefabricated members serving as main stress members. The method is one of important directions for building structure development in China, and has positive significance in improving production efficiency, saving energy, developing green and environment-friendly buildings and improving and ensuring the quality of building engineering compared with a cast-in-place construction method. In the fabricated concrete structure, the connection node is a key link in construction quality control, the sleeve grouting connection is most widely applied in the existing connection modes, and the sleeve used by the sleeve grouting joint is generally cast by nodular cast iron or high-quality carbon structural steel and is mostly cylindrical or spindle-shaped. The grouting material is a dry mixture which is prepared by taking cement as a basic material, adding proper fine aggregate, a small amount of concrete admixture and other materials, and has the performances of high fluidity, early strength, high strength, slight expansion and the like after being stirred by adding water. In the form of a sleeve, the overall structure can be divided into a full-sleeve grouting joint and a half-sleeve grouting joint (as shown in fig. 3). In practical engineering application, the sleeves are embedded into the connecting ends of the members in advance when the prefabricated members are manufactured, and the exposed steel bars of the other connecting member are inserted into the sleeves and are connected with the steel bars through grouting after the sleeves and the members are installed and positioned in site construction. Compared with welding, straight thread mechanical connection and other modes, the sleeve grouting connection has the advantages that the steel bar preprocessing workload can be reduced, the steel bar can not generate secondary stress and deformation during site construction, relatively large T-shaped deviation can be accepted, and the like. The reliability of the sleeve grouting connection is mainly controlled by two indexes, namely the length of the steel bar extending into the sleeve and the grouting fullness. The traditional detection means, such as an ultrasonic method, an impact echo method and an X-ray method, have poor and satisfactory detection effects on the 2 indexes, and are complex to operate, such as the X-ray method, an X-ray flaw detector needs to be equipped, detection personnel need to be located beyond a safe distance, and the exposure film blackness value needs to be controlled to be 2.0-3.0, and the like. The application number 201910170761.4 discloses a method for detecting prefabricated concrete structure sleeve grouting quality, through before the grout process, the pipe of the depth of insertion to sleeve inner wall in sleeve grout outlet pipeline, is extracted after grouting material sets finally, be the cavity in the pipe for instance to the eye, judge that the sleeve grout is not full promptly, otherwise, if the fracture face of visible pipe horizontal segment tip and sleeve inner wall grouting material, then the grouting material is full in the pipe, take out the solid grouting material in the pipe and make the cylinder test piece, measure the test piece. But this method is random and haphazard.

The current warm up with the help of infrared ray detection blocks up (learning hot-water line distribution through the thermal imaging appearance), seepage location, heating effect verify, but need open the underfloor heating system during the use to produce certain difference in temperature with ambient temperature, and the factor that produces the difference in temperature depends on, the thickness of underfloor heating pipeline temperature, ground decoration's material, ground decorative layer, ambient temperature etc. and this application detects assembled concrete grout sleeve reinforcing bar anchor length with the help of infrared imaging, has not reported yet.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a method for detecting the anchoring length of the steel bar of the assembled concrete grouting sleeve based on an infrared imaging principle, the anchoring length of the steel bar in the sleeve is displayed by a thermal imager, the imaging effect is good, the anchoring length of the steel bar in the grouting sleeve can be clearly observed, the judgment requirement on the construction quality of the sleeve is met, and the site construction is convenient (if the anchoring length meets 8day, the construction requirement is met).

In order to achieve the above object, the present invention adopts the following technical scheme

A method for detecting the anchoring length of a steel bar of an assembled concrete grouting sleeve based on an infrared imaging principle comprises the following steps:

(1) connecting the prefabricated part to be detected by adopting a grouting sleeve, chiseling a base grout layer 5cm away from the periphery of the steel bar to be detected to form a chiseled base grout layer, and exposing a part of the steel bar inserted into the grouting sleeve, wherein the exposed length of the steel bar is within the range of 3 cm;

(2) installing electromagnetic heating equipment and an infrared thermal imager, and locally heating the exposed steel bars by adopting the electromagnetic heating equipment; the locally heated steel bars transmit heat to the grouting material, and the grouting material transmits the heat to the surface of the concrete prefabricated part; the electromagnetic heating device consists of an electromagnetic heating controller and an electromagnetic heating coil.

The electromagnetic heating device consists of an electromagnetic heating controller and an electromagnetic heating coil.

(3) The infrared thermal imager detects the concrete surface, forms infrared thermal image, judges the anchor length of reinforcing bar through the difference of colour on the image.

The infrared detector and the optical imaging objective lens are used for receiving an infrared radiation energy distribution pattern of a detected target and reflecting the infrared radiation energy distribution pattern on a photosensitive element of the infrared detector, so that an infrared thermography is obtained, and the thermography corresponds to a thermal distribution field on the surface of an object. The anchoring length of the reinforcing steel bar is judged through the difference of colors on the image, the displayed colors can be judged through the difference of the heat of the image, and the displayed colors with higher heat are heavier.

The floor heating detection is that the temperature of hot water in the floor heating is detected by imaging through an infrared thermal imager after being transmitted outwards. The material detected by the invention is different, the heat is transferred to the grouting material and the concrete by heating the reinforcing steel bar, and the anchoring length of the reinforcing steel bar is detected by imaging through an infrared thermal imager.

Has the advantages that:

(1) when the anchoring length of the steel bars in the grouting sleeve is detected, only a small part of concrete needs to be chiseled, and the steel bars in the grouting sleeve are leaked, so that the damage to the components is small, the construction is convenient, and the later repair is convenient.

(2) The electromagnetic heating equipment is adopted to locally heat the reinforcing steel bars, so that the heating speed is high, and the time is saved.

(3) The heat transfer is to prefabricated component surface concrete, adopts infrared thermal imager to form images, and the anchor length of observation reinforcing bar that can be comparatively clear, the operation is fairly simple.

Overall, the invention has the advantages that the anchoring length of the steel bar in the grouting sleeve can be observed more clearly through the imaging processing of the infrared thermal image vision system, and the field construction is convenient.

Drawings

FIG. 1 is an imaging schematic diagram of a thermal infrared imager according to the present invention;

FIG. 2 is a schematic view of a grout sleeve joint;

FIG. 3 is a schematic view of the instrument arrangement after the grout layer has been cut;

FIG. 4 is an image of an infrared thermal imager, showing different imaging colors at different temperatures;

FIG. 5 is a schematic flow chart of the present invention.

Wherein: the construction method comprises the following steps of prefabricating a component-1, a grouting sleeve-2, a seat paste layer-3, a seat paste layer-4, a power supply-5, a heating coil-6 and a lead-7.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

Referring to fig. 1, the thermal infrared imager adopts the working principle that the thermal infrared imager receives the infrared radiation energy distribution pattern of the target to be measured by using the infrared detector and the optical imaging objective lens and reflects the infrared radiation energy distribution pattern on the photosensitive element of the infrared detector, so as to obtain the infrared thermography. In the application, the thermal distribution field formed on the surface of the prefabricated part after being heated by the electromagnetic corresponds to the infrared thermal image. The difference of heat is judged according to the color of the image (shown in fig. 4), the color of the area with higher heat is darker, the anchoring length of the steel bar is judged according to the difference of the color on the image, and the anchoring length of the steel bar can be clearly observed.