Quantitative evaluation method and system for concrete bonding surface roughness based on DIC

Abstract

The present invention discloses a DIC-based quantitative evaluation method and system for concrete bonding surface roughness. The method comprises: performing speckle processing on a target concrete bonding surface; obtaining a speckle image of the treated target concrete bonding surface; analyzing the speckle image using the DIC measurement method to obtain a three-dimensional contour map of the target concrete bonding surface; obtaining the increments of multiple trace heights at the measured location based on the three-dimensional contour map; and analyzing the increments of the multiple trace heights to obtain the roughness of the target concrete bonding surface. This method can quickly, conveniently, and accurately evaluate the roughness of a concrete bonding surface.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete bonding surface roughness evaluation, and in particular to a DIC-based concrete bonding surface roughness quantitative evaluation method and system. Background Art

[0002] The roughness of the concrete bonding surface is a comprehensive reflection of the concrete microstructure and other complex factors. It is an important parameter that determines the interfacial bond strength. Current roughness evaluation methods include the sand filling method, the silica powder pile method, the observation method, and the dimension analyzer measurement method. The patent "A Concrete Roughness Measurement Method (CN101261111A)" invented a concrete roughness measurement method. The concrete surface roughness is calculated by drawing the morphological contour curve of the concrete surface, which solves the problem that the sand filling method cannot be used for roughness testing of non-horizontal and irregular components. However, this invention can only be used to evaluate the roughness of a certain section of the concrete surface, and each measurement requires a contour curve analyzer to draw, which is relatively cumbersome. The patent "A Prefabricated Concrete Roughness Detection Method (CN 111174679 A)" invented a prefabricated concrete roughness detection method. The roughness of the prefabricated concrete is calculated by making a silicone mold, but the mold forming process is long and cannot be quickly evaluated. The patent "A handheld concrete roughness three-dimensional detection device and method (CN 112414327 A)" invented a handheld concrete roughness three-dimensional detection device, which observes the surface roughness of concrete through three-dimensional scanning technology, but the invention has high requirements for test equipment.

[0003] The current concrete roughness testing methods and systems still have the following problems:

[0004] (1) Low precision of roughness test results: The roughness of the concrete bonding surface measured by the commonly used sand filling method, silica powder piling method, and observation method is greatly affected by human factors, and the roughness results are of low precision;

[0005] (2) The roughness test equipment is complex: Although the roughness measured by existing methods such as dimension analyzer or laser scanning is more accurate, the equipment operation is cumbersome and not conducive to the rapid evaluation of the roughness of the concrete bonding surface.

[0006] (3) High requirements on specimen size and shape: The commonly used sand filling method and silica powder pile method cannot be used to measure non-horizontal components and irregular concrete bonding surfaces. The use of dimension analyzer or laser scanning is also limited in the size of concrete specimens due to the limitations of equipment size and measurement range, and its applicability is poor.

[0007] Therefore, how to quickly, conveniently and accurately evaluate the roughness of the concrete bonding surface is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0008] In view of the above problems, the present invention provides a DIC-based concrete bonding surface roughness quantitative evaluation method and system that solves at least some of the above technical problems, which can quickly, conveniently and accurately evaluate the roughness of the concrete bonding surface.

[0009] In one aspect, an embodiment of the present invention provides a method for quantitatively evaluating the roughness of a concrete bonding surface based on DIC, comprising:

[0010] S1. Perform speckle treatment on the target concrete bonding surface;

[0011] S2, obtaining a speckle image of the target concrete bonding surface after speckle processing;

[0012] S3. Analyzing the speckle image based on a DIC measurement method to obtain a three-dimensional contour image of the target concrete bonding surface;

[0013] S4. Obtaining an increment of a plurality of trace heights at a portion to be measured according to the three-dimensional contour map;

[0014] S5. Analyze the increments of the plurality of trace heights to obtain the roughness of the target concrete bonding surface.

[0015] Furthermore, the S4 specifically includes:

[0016] S41, based on the three-dimensional contour map, determining the roughness measurement position to be measured, the number of traces, and the trace distribution position according to preset conditions;

[0017] S42, obtaining trace height-trace vertical projection length curves corresponding to the plurality of traces according to the roughness measurement location, the number of traces, and the trace distribution location;

[0018] S43. Obtain multiple trace height increments based on the multiple trace height-trace vertical projection length curves.

[0019] Furthermore, the S41 specifically includes: selecting a concrete bonding surface with an area of ​​100 mm×100 mm as a roughness measurement location; selecting traces with a trace spacing of 25 mm to 40 mm and evenly distributing them at the roughness measurement location.

[0020] Furthermore, the S5 specifically includes:

[0021] S51, calculating the roughness of the corresponding trace according to the increment of the height of each trace;

[0022] S52. Taking the average value of the roughness of the plurality of traces as the roughness of the target concrete bonding surface.

[0023] Furthermore, the roughness of the target concrete bonding surface is divided into four levels: smooth, relatively rough, rough, and extremely rough.

[0024] On the other hand, an embodiment of the present invention further provides a DIC-based concrete bonding surface roughness quantitative evaluation system, applying the above method, the system includes: an image acquisition subsystem and a data analysis subsystem;

[0025] The image acquisition subsystem includes a speckle stamp and an image acquisition device;

[0026] The speckle stamp is used to perform speckle treatment on the target concrete bonding surface;

[0027] The image acquisition is used to capture the speckle image of the target concrete bonding surface after the speckle treatment;

[0028] The data analysis subsystem is configured to analyze the speckle image to obtain a three-dimensional contour map of the target concrete bonding surface; obtain, based on the three-dimensional contour map, an increment of a plurality of trace heights at a measured portion; and analyze the increment of the plurality of trace heights to obtain a roughness of the target concrete bonding surface.

[0029] Furthermore, the speckle stamp is a sponge with black spots on a white background sprayed with paint.

[0030] Furthermore, the image acquisition device is a camera with a resolution of more than 5 million pixels.

[0031] Compared with the prior art, the DIC-based concrete bonding surface roughness quantitative evaluation method and system described in the present invention has the following beneficial effects:

[0032] 1. The test is simple to operate. The present invention only requires taking an image of the concrete bonding surface after speckle treatment to analyze and obtain the roughness of the concrete bonding surface.

[0033] 2. Strong applicability and low requirements on the size of concrete specimens. The present invention can measure the roughness of the bonding surface of concrete specimens with a photo resolution of 5 million pixels or more. It does not require the shape of the concrete specimen and can be used to test the roughness of the bonding surface of any concrete specimen.

[0034] 3. Accurate calculation results: The accuracy of parameters such as trace height obtained by the DIC technology in the present invention is higher than that of conventional fractometer measurements, making the roughness calculation results more accurate.

[0035] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0036] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0038] Figure 1 This is a schematic flow chart of a method for quantitatively evaluating the roughness of a concrete bonding surface based on DIC provided in an embodiment of the present invention.

[0039] Figure 2 This is a speckle image provided by an embodiment of the present invention.

[0040] Figure 3 A three-dimensional contour map of the target concrete bonding surface provided by an embodiment of the present invention.

[0041] Figure 4 A schematic diagram of trace distribution provided by an embodiment of the present invention.

[0042] Figure 5 Schematic diagram of the X(t)-1 curve of four traces provided in an embodiment of the present invention.

[0043] Figure 6 Schematic diagram of the structure of the DIC-based concrete bonding surface roughness quantitative evaluation system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0045] See also Figure 1 As shown, the embodiment of the present invention provides a quantitative evaluation method for the roughness of the concrete bonding surface based on DIC, which specifically includes the following steps:

[0046] S1. Perform speckle treatment on the target concrete bonding surface;

[0047] S2, obtaining a speckle image of the target concrete bonding surface after speckle processing;

[0048] S3. Analyzing the speckle image based on a DIC measurement method to obtain a three-dimensional contour image of the target concrete bonding surface;

[0049] S4. Obtaining an increment of a plurality of trace heights at a portion to be measured according to the three-dimensional contour map;

[0050] S5. Analyze the increments of the plurality of trace heights to obtain the roughness of the target concrete bonding surface.

[0051] In the above step S1, in order to accurately capture the height of the concrete bonding surface, the target concrete bonding surface is subjected to speckle processing;

[0052] In the above step S2, the speckle image of the target concrete bonding surface after speckle processing is obtained as follows: Figure 2 As shown;

[0053] In the above step S3, the concrete surface speckle is matched with the corresponding speckle spots in the reference image and the deformation image by the DIC technology to obtain the displacement and deformation of the concrete surface, and the three-dimensional contour map of the target concrete bonding surface is obtained by coordinate reconstruction, as shown in FIG. Figure 3 Specifically, the basic principle of the roughness quantification evaluation method is to use the reference image and deformation image obtained after speckle processing as the basis to calculate the three-dimensional strain cloud map, assuming that the reference image is f(x ij ), the deformation graph is g(x ij ), point P in the reference image moves by u0 to position P′ in the deformation image. By estimating the position of P′, we can estimate u0. To do this, we select an N×N computational subregion centered at P in the reference image and calculate the displacement variable of the concrete rough surface using the texture information of the entire subregion.

[0054] In the above step S4, it specifically includes:

[0055] S41. Based on the three-dimensional contour map, determine the roughness measurement location, number of traces, and trace distribution location to be measured according to preset conditions. The trace is the actual measured concrete cross-section location. The more traces there are, the higher the test accuracy. Specifically, a concrete bonding surface with an area of ​​100 mm × 100 mm is selected as the roughness measurement location. When the trace spacing is greater than 40 mm, the measurement accuracy is low and inconsistent with the actual roughness. When the trace spacing is less than 25 mm, the distance between the traces is too close and has little effect on the results. Therefore, based on the actual specimen size, traces with a trace spacing of 25 mm to 40 mm should be evenly distributed at the roughness measurement location.

[0056] In the embodiment of the present invention, 4 traces are selected with a trace spacing of 25 mm and evenly distributed at the roughness measurement site. Figure 4 As shown;

[0057] S42, obtaining a trace height X(t)-trace vertical projection length l(mm) curve corresponding to the plurality of traces, i.e., an X(t)-l curve, according to the roughness measurement location, the number of traces, and the trace distribution location;

[0058] In the embodiment of the present invention, the X(t)-1 curves of the four traces are as follows: Figure 5 As shown,

[0059] S43. Based on multiple X(t)-l curves, obtain the increment V(τ) of multiple trace heights; the corresponding calculation method is:

[0060] V(τ)=[X(t0+τ)-X(t0)] 2

[0061] Where V(τ) is the increment of the trace height, which represents the square mean of the trace height increment between two points; τ is the distance between the two trace measurement points; t0 is the starting point of the trace; and X(·) is the trace height at ·.

[0062] In the above step S5, it specifically includes:

[0063] S51, calculating the roughness D of the corresponding trace according to the increment V(τ) of the height of each trace;

[0064] S52, taking the average roughness of multiple traces as the roughness of the target concrete bonding surface The calculation method is:

[0065]

[0066] Where N is the specified number of traces; τ i is the distance between the i-th trace and the first trace; is the roughness of the target concrete bonding surface; the roughness of the target concrete bonding surface It can be divided into four grades according to size: smooth (2-1.6), relatively rough (1.6-1.3), rough (1.3-0.9), and extremely rough (0.9-0);

[0067] In the embodiment of the present invention, the roughness D of the target concrete bonding surface finally outputted is 0.91, which is extremely rough.

[0068] On the other hand, the embodiment of the present invention also provides a concrete bonding surface roughness quantitative evaluation system based on DIC, applying the above method, the system includes: an image acquisition subsystem 2 and a data analysis subsystem 3; Figure 6 shown; wherein:

[0069] The image acquisition subsystem 2 includes a speckle stamp and an image acquisition device;

[0070] Speckle stamp 1 is a sponge with black spots on a white background sprayed with paint, which is used to apply speckle treatment to the target concrete bonding surface;

[0071] The image acquisition is carried out by a camera with a resolution of more than 5 million pixels, which is used to capture the speckle image of the target concrete bonding surface after speckle treatment;

[0072] The data analysis subsystem 2 is used to analyze the speckle image to obtain a three-dimensional contour map of the target concrete bonding surface; obtain the increment of multiple trace heights at the measured part based on the three-dimensional contour map; and analyze the increment of multiple trace heights to obtain the roughness of the target concrete bonding surface.

[0073] The embodiments of the present invention disclose a method and system for quantitatively evaluating the roughness of concrete bonding surfaces based on DIC. Based on the displacement field test results of DIC, a method for calculating the roughness of concrete bonding surfaces is constructed, and an intelligent operating system for the roughness of concrete bonding surfaces is established. By selecting the number of measurement traces and the trace distribution range in the intelligent operating system, the roughness of different locations on the concrete bonding surface can be quickly evaluated.

[0074] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0075] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A quantitative evaluation method for concrete bonding surface roughness based on DIC, characterized in that: include: S1. Perform speckle treatment on the target concrete bonding surface; S2, obtaining a speckle image of the target concrete bonding surface after speckle processing; S3. Analyzing the speckle image based on a DIC measurement method to obtain a three-dimensional contour image of the target concrete bonding surface; S4. Obtaining an increment of a plurality of trace heights at a portion to be measured according to the three-dimensional contour map; S5. Analyze the increments of the plurality of trace heights to obtain the roughness of the target concrete bonding surface; In said S3, based on the DIC technology, the concrete surface speckle is matched with the corresponding speckle spots in the reference image and the deformation image by image texture, so as to obtain the displacement and deformation of the concrete surface, and the three-dimensional contour image of the target concrete bonding surface is obtained by coordinate reconstruction; The S4 specifically includes: S41, based on the three-dimensional contour map, determining the roughness measurement position to be measured, the number of traces, and the trace distribution position according to preset conditions; S42, obtaining trace height-trace vertical projection length curves corresponding to the plurality of traces according to the roughness measurement location, the number of traces, and the trace distribution location; S43, obtaining a plurality of trace height increments based on the plurality of trace height-trace vertical projection length curves; In the above step S5, it specifically includes: S51, calculating the roughness D of the corresponding trace according to the increment V(τ) of the height of each trace; S52, taking the average roughness of multiple traces as the roughness of the target concrete bonding surface The calculation method is: Where N is the specified number of traces; τ i is the distance between the i-th trace and the first trace; is the roughness of the target concrete bonding surface.

2. The DIC-based quantitative evaluation method for concrete bonding surface roughness according to claim 1, wherein: The S41 specifically includes: selecting a concrete bonding surface with an area of ​​100 mm×100 mm as a roughness measurement location; selecting traces with a trace spacing of 25 mm to 40 mm and evenly distributing them at the roughness measurement location.

3. The DIC-based quantitative evaluation method for concrete bonding surface roughness according to claim 1, wherein: The roughness of the target concrete bonding surface is divided into four levels: smooth, relatively rough, rough, and extremely rough.

4. The DIC-based concrete bonding surface roughness quantitative evaluation system is characterized by: Applying the method described in any one of claims 1 to 3 above, the system comprises: an image acquisition subsystem and a data analysis subsystem; The image acquisition subsystem includes a speckle stamp and an image acquisition device; The speckle stamp is used to perform speckle treatment on the target concrete bonding surface; The image acquisition is used to capture the speckle image of the target concrete bonding surface after the speckle treatment; The data analysis subsystem is configured to analyze the speckle image to obtain a three-dimensional contour map of the target concrete bonding surface; obtain, based on the three-dimensional contour map, an increment of a plurality of trace heights at a measured portion; and analyze the increment of the plurality of trace heights to obtain a roughness of the target concrete bonding surface.

5. The DIC-based concrete bonding surface roughness quantitative evaluation system according to claim 4, characterized in that: The speckle stamp is a sponge with black spots on a white background sprayed with paint.

6. The DIC-based concrete bonding surface roughness quantitative evaluation system according to claim 4, characterized in that: The image acquisition device is a camera with a resolution of more than 5 million pixels.

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