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Application of A1040 MIRA in the inspection of prefabricated concrete structures
来源: | 作者:Frank | 发布时间:2020-01-01 | 10 次浏览 | Share:
A1040 MIRA Ultrasonic Tomography Imager is also called Array Ultrasonic Imager. This equipment has advantages that other detection methods can’t compare to the structure detection of assembled structures. It only needs one measuring surface to perform dry coupling test. Visualization of the internal structure, displaying the 3D image of the internal structure of the object and the various viewing angles of the structure and is not sensitive to steel bars, and excellent detection results can also be obtained for areas with dense steel bars
1. Project overview:
The inspection project is set by a certain unit to inspect the prefabricated concrete structure. The structure to be inspected is the double-skin wall in the prefabricated building. During the pouring process, the user often has a large area of voids between the grouting and precast slab Disease, there is no suitable visual imaging detection equipment, in order to solve such problems, our company provides equipment for detailed inspection of the structure.
2. Testing content and main testing equipment
1.1 Main testing content
It mainly detects whether there are obvious defects inside the concrete structure, such as whether there are voids in the joint surface, internal void defects, cracks and other diseases.
1.2 Main testing equipment
The equipment used this time is the A1040 MIRA ultrasonic tomographic imager developed and produced by the Russian ACS company, which is represented by Beijing IST Technology Development Co., Ltd. and provides technical support and after-sales service. The A1040 MIRA Ultrasonic Tomography Imager is currently the most advanced instrument and equipment used to test the internal defects of concrete structural units and display them in three-dimensional graphics or tomographic pictures. An antenna composed of a series of dry point contact sensors is used to transmit shear waves into the concrete, and then receive the reflected shear waves to form a one-shot and one-collect ultrasonic technology. The host computer creates a three-dimensional image of the detection unit based on the original data. see picture 1
Figure 1
3. Testing data processing analysis
3.1. Test wall (1):
Test area planning:
Through grid planning, the actual test area is 110×120cm, the X step length is set to 200mm, and the Y step length is set to 100mm.
By measuring the known thickness value, setting the speed value through the known thickness setting, and adjusting to the best test parameter (wave speed 2680m/s), the following planning area is tested, as shown in Figure 2.
Figure 2
Actual test instructions:
Defect detection verification: adjust the amplitude and color gain processing through the software and combine the B-Scan, C-Scan, D-Scan and three-dimensional graphics rotation in the software and the actual structure (see Figure 3):
1. The first abnormal area is judged by displaying in the upper left corner of the B-Scan diagram and combining the left area in the C-Scan and D-Scan diagrams. According to the 3D diagram, it can be seen that there are two long strips side by side. The specific abnormal area is to be verified.
2. The second abnormal area is indicated by the C-Scan graphic. Here, the abnormality is combined with the ruler to measure the thickness and its performance in the three-dimensional graphic, and the distance from the measured surface is 15cm, where the area should be vacant.
3. The third abnormal area is represented by C-Scan graphics and refers to the actual situation. This is the area where the cassette is located.

Figure 3
3.2 Test wall (2)
Test area planning:
In order to verify the accuracy of the detection imaging after slotting, a complete area was selected to avoid the opening for testing (see Figure 4).
Figure 4
Description of actual detection effect:
The groove depth is 10mm. After the bottom reflection interface and the invalid data at the rear are filtered out by the software, the thickness groove area on the back is clearly displayed, which proves that the defect imaging of the equipment is accurate and clear (see Figure 5).
Figure 5
3.Test wall-window part (1)
Test area planning:
In order to verify the reliability of the equipment detection, a single-point B-Scan test was carried out on the lower part of the window. The overall thickness of the structure was 20cm, and there was foam filling at the rear 5cm (see Figure 6).
Figure 6
Actual test instructions:
Through the B-Scan single-point inspection, it can be seen that the bottom rear wall reflection position is 150mm, which is consistent with the actual structure thickness. The ultrasonic wave reflects the material with a large difference in acoustic impedance at the interface (see Figure 7).
Figure 7
3.4 Test wall-window part (2)
Test area planning:
This test wall is divided into four areas for testing, namely the bottom of the window, the upper left of the window, the back of the upper left of the window, and the back of the upper right of the window. The overall thickness is 20cm (see Figure 8).
Figure 8
Actual test instructions:
(1) Test at the bottom of the window
After the data graphics are processed, it can be seen from the graphics that the overall thickness is in line with the actual thickness, and there is a small area of void disease at the rear of the structure (see Figure 9-1). The distribution of steel bars can be clearly seen after processing through the software section (see Figure 9-2).
Figure 9-1
Figure 9-2
(2) Frontal test on the upper left of the window
The bottom interface is reflected at 15cm, and echoes are reflected repeatedly at 15cm intervals. The actual overall thickness of the structure is 20cm, and the thickness of the rear plate is 5cm. There is a large area of void between the rear plate and the grouting body, and the echo is reflected at the bottom of the equipment. Principle, so it can be judged according to the actual structure situation that there is a large area of void here, as shown in Figure 10;
Figure 10
In order to verify the accuracy of the detection, the opposite structure is detected at this detection site. It can be seen from Figure 11 that the first interface reflected wave is at 5cm, and the echo is reflected multiple times at 5cm intervals, combined with the figure 10 window front graphic data Judgment, confirm that there is a voiding disease in the 5cm grouting slurry;
Figure 11
4. Test conclusion
A1040 MIRA Ultrasonic Tomography Imager is also called Array Ultrasonic Imager. This equipment has advantages that other detection methods can’t compare to the structure detection of assembled structures. It only needs one measuring surface to perform dry coupling test. Visualization of the internal structure, displaying the 3D image of the internal structure of the object and the various viewing angles of the structure and is not sensitive to steel bars, and excellent detection results can also be obtained for areas with dense steel bars. Compared with geological radar, impact echo and other methods, the detection accuracy is higher and easier to identify, especially for the detection of equal-thickness structures, and the detection results are accurate. This detection is very affirmed by customers.
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