Method for determining joint surface processing

Abstract

An object of the present invention is to solve the problems of the prior art, that is, to provide a method for determining the quality of a placing joint surface treatment, which can objectively determine the quality of the placing joint surface treatment after estimating the distribution state of aggregates on a concrete surface.SOLUTION: The construction joint surface processing determination method is a method for determining the quality of construction joint surface processing on the basis of an original image obtained by photographing a concrete surface, and includes an original image acquisition process and an aggregate extraction process. In the original image acquisition step, a first smoothed image and a second smoothed image are generated by smoothing an original image. In the aggregate extraction step, a portion where a pixel value difference between the first smoothed image and the second smoothed image exceeds an aggregate threshold value is extracted as an aggregate portion. To determine the quality of placing joint surface processing on the basis of the ratio of an aggregate part occupying an object area corresponding to an original image.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to concrete joint surface treatment, and more specifically, to a method for determining whether or not the joint surface treatment is good based on an image of the concrete surface. Method for determining joint surface treatment It is related to. [Background technology]

[0002] Along with steel, concrete is one of the most important construction materials, and is used in a variety of structures, including civil engineering structures such as dams, tunnels, and bridges, as well as architectural structures such as apartment buildings and office buildings. While these concrete structures are sometimes prefabricated in factories and transported to their designated locations, civil engineering and architectural structures are often constructed directly at the designated location (site). In either case, concrete structures are constructed by pouring fresh concrete, a mixture of cement, water, aggregate, admixtures, etc., into formwork, waiting for the concrete to harden, and then removing the formwork.

[0003] Fresh concrete is poured into the formwork by pouring it through a chute from an agitator truck, dropping it from a hose using a concrete pump truck, pouring it into the designated location through pre-installed pipes, or in some cases by workers splashing it with a shovel. The fresh concrete poured into the formwork is vibrated using a vibrator (vibrating vibrator), and as liquefaction progresses due to this vibration, air bubbles within the concrete rise and escape to the outside, and the aggregate and mortar inside are rearranged, resulting in the concrete being compacted.

[0004] When constructing concrete structures of a certain height, such as dams or large retaining walls, it can be difficult to pour concrete all at once (i.e., for the entire height at the same time) due to construction conditions such as the concrete supply capacity and restrictions on the placement of concrete pumps. In such cases, it is common to plan the vertical block division (so-called lift division) in advance based on conditions such as the concrete supply capacity, and then pour the concrete. However, if the concrete of upper and lower blocks is poured in succession (overlapping) after leaving time between them in this way, pouring joints (especially horizontal joints) will occur between the upper and lower blocks.

[0005] When fresh concrete is poured into a formwork, relatively heavy particles such as aggregate sink to the bottom, while lighter particles such as cement tend to rise to the surface along with the bleeding water. Furthermore, if the lighter particles that rise to the surface accumulate to a certain extent on the concrete surface, a weak layer known as laitance, a layer of poor quality concrete, or loose aggregate may form. If the concrete of the upper layer is poured (jointed) while such a laitance layer has formed on the surface of the lower layer concrete, a cold joint, a discontinuous surface, will form. These cold joints not only have a poor appearance, but also present structural weaknesses such as cracking, and are also a weakness in terms of watertightness.

[0006] Therefore, the "Standard Specifications for Concrete - Construction Edition" (hereinafter simply referred to as the "Standard Specifications") stipulates that "When joining concrete, laitance, poor-quality concrete, loose aggregate, etc. must be completely removed from the surface of the previously poured concrete, the concrete surface must be roughened, and the new concrete must be allowed to absorb water thoroughly." The Standard Specifications also outline methods for treating the interface between the lower and upper layers of concrete (hereinafter referred to as the "joint surface"). For example, the Standard Specifications cite a "green cut" technique, which uses pressurized air or water to remove a thin layer of concrete (such as laitance) from the surface after the previously poured lower layer has finished setting, exposing the coarse aggregate. Furthermore, when performing green cut on large joints, some of the concrete begins to harden, making treatment difficult. Therefore, the Standard Specifications recommend spraying a set retarder, such as sodium gluconate, on the concrete surface beforehand. In addition, the book shows various methods for treating joint surfaces depending on the strength of the concrete, such as scraping the surface with a wire brush while spraying water on it, or sandblasting the surface and then rinsing it with water.

[0007] While careful, time-consuming surface preparation naturally results in a good joint, careless surface preparation can result in an insufficient roughness on the joint, potentially leading to cold joints. Excessive surface preparation can also result in extremely uneven joints, resulting in unnecessary labor and material loss. Therefore, it is necessary to carefully monitor the condition of the joint during surface preparation. Traditionally, the quality of joints has been judged by experienced technicians. However, the construction industry has recently been plagued by a chronic labor shortage, making it difficult to secure such skilled technicians. However, if inexperienced technicians judge the quality of joints, they may make an incorrect judgment, resulting in problems associated with insufficient or excessive surface preparation.

[0008] Therefore, various techniques have been proposed to quantitatively (objectively) judge the quality of concrete joint surface treatment, without relying on the subjective judgment of the judge, and without relying on the qualitative judgment of an engineer. For example, Patent Document 1 proposes a technique for evaluating the quality of concrete joint surface treatment by using images of the concrete surface. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-090360 Summary of the Invention [Problem to be solved by the invention]

[0010] The technology disclosed in Patent Document 1 divides image data of a construction joint surface into multiple image blocks, and evaluates the construction joint surface treatment by comparing the brightness histogram created for each image block with a predetermined threshold. In other words, it is an evaluation method that estimates the proportion of aggregate on the concrete surface based on the brightness histogram of the image block. This technology is advantageous because it allows for objective evaluation of construction joint surface treatment without relying on the subjective judgment of the engineer.

[0011] However, while the technology disclosed in Patent Document 1 is a method for estimating the presence of aggregate based on a brightness histogram, it does not directly estimate the distribution of aggregate. In other words, it is a method for evaluating the treatment of the construction joint surface without grasping (or estimating) the aggregate distributed on the concrete surface. As a result, the person who obtains the assessment result cannot intuitively judge whether the result is correct, and even if they are skeptical of the assessment result based on the actual situation, there is no way to confirm it.

[0012] The object of the present invention is to solve the problems of the prior art, that is, to estimate the distribution of aggregate on the concrete surface and objectively judge the quality of the joint surface treatment. Method for determining joint surface treatment The purpose is to provide [Means for solving the problem]

[0013] The present invention was made by focusing on the fact that by smoothing an original image, two types of smoothed images are generated, namely, a smoothed image that emphasizes aggregates and a smoothed image that does not make aggregates stand out, and that the distribution of aggregates on the concrete surface is estimated based on the difference between these two types of smoothed images, and is an invention based on an unprecedented idea.

[0014] The method for determining the quality of concrete joint surface treatment of the present invention is a method for determining the quality of concrete joint surface treatment based on an original image of a concrete surface, and includes an original image acquisition step and an aggregate extraction step. In the original image acquisition step, the concrete surface is subjected to a concrete joint surface treatment, and then an original image is acquired by photographing the concrete surface, and the original image is smoothed to generate a first smoothed image and a second smoothed image. In the aggregate extraction step, the pixel value difference between the first smoothed image and the second smoothed image is calculated, and portions where this pixel value difference exceeds an aggregate threshold are extracted as aggregate portions. The first smoothed index image is an image generated by smoothing processing so that aggregate portions are emphasized more than in the second smoothed index image. The quality of concrete joint surface treatment is then determined based on the proportion of aggregate portions in the target area corresponding to the original image.

[0015] The method for determining the treatment level of a concrete joint of the present invention may further include a treatment level determination step, in which the aggregate distribution ratio of the target area, which is the aggregate portion, is calculated, and the degree of treatment of the concrete joint in the target area is determined by comparing the aggregate distribution ratio with a treatment level threshold.

[0016] The method for determining the treatment level of a concrete joint surface according to the present invention can also be a method for setting the treatment level of a concrete joint surface in three or more stages. Specifically, by setting a treatment level threshold of two or more stages in advance, the treatment level of a concrete joint surface, which indicates the degree of treatment of the concrete joint surface, is set in three or more stages. In this case, the treatment level determination step determines the treatment level of the concrete joint surface in the target area by comparing the aggregate distribution ratio with two or more treatment level thresholds.

[0017] The present invention also provides a method for determining the treatment level of concrete joints by having an operator photograph the surface of the concrete using the photographing means of a tablet PC. In this treatment level determination process, the aggregate distribution ratio of the target area, which is the aggregate portion, is calculated, and the degree of treatment level of the target area is determined by comparing the aggregate distribution ratio with a treatment level threshold. [Effects of the Invention]

[0018] Method for determining joint surface treatment of the present invention has the following effects: (1) It is possible to objectively evaluate the construction joint surface treatment without relying on the subjective judgment of the evaluator. As a result, it is possible to construct concrete structures with excellent mechanical properties, durability, waterproofing, and appearance. (2) Objective evaluation is possible, which avoids the difficulty of securing skilled engineers with ample experience. (3) In addition to objective evaluation, the reproducibility of the evaluation, i.e., traceability of the evaluation, can be ensured, which improves the reliability of the evaluation of joint surface treatment and also enables accountability, thereby gaining the trust of customers. (4) Based on the results of experimental implementation of the present invention, good judgment results were obtained regardless of whether the concrete surface was dry or wet. Furthermore, good judgment results were obtained even when using original images taken at an oblique angle (for example, at a 45° angle) rather than facing directly at the object. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a block diagram showing the main configuration of a joint surface treatment determination system. [Figure 2] FIG. 1 is a model diagram showing a "filter" in median filtering. [Figure 3] FIG. 10 is a model diagram schematically showing a "difference image" based on the pixel value difference between a "first smoothed image" and a "second smoothed image." [Figure 4] FIG. 10 is a model diagram showing a "segmentation target region" formed by dividing a differential image. [Figure 5] FIG. 1 is a flow chart showing the main processing flow of the joint surface treatment determination system. [Figure 6] A flow chart showing the main processing flow of the joint surface treatment determination system up to determining the aggregate threshold value and treatment level threshold value. [Figure 7] 1 is a flow chart showing the main steps of the joint surface treatment determination method of the present invention. [Figure 8] (a) is a model diagram showing the results of judging the degree of joint surface treatment of a dry concrete surface using the joint surface treatment judgment system, and (b) is a model diagram showing the results of judging the degree of joint surface treatment of a wet concrete surface using the joint surface treatment judgment system. DETAILED DESCRIPTION OF THE INVENTION

[0020] Construction joint surface treatment judgment system, and Method for determining joint surface treatment of the present invention An example of the implementation will be described with reference to the drawings.

[0021] 1.Concrete joint surface treatment judgment system Introduction Construction joint surface treatment judgment systemThe method for determining the treatment of the construction joint surface of the present invention is as follows: Construction joint surface treatment judgment system This is a method to judge the quality of the joint surface treatment using Construction joint surface treatment judgment system The above will be explained, and then the method for determining joint surface treatment of the present invention will be explained.

[0022] Figure 1 shows Construction joint surface treatment determination system 100 This is a block diagram showing the main components of the Construction joint surface treatment determination system 100 is configured to include a smoothing processing means 101 and an aggregate extraction means 102, and may further include a processing degree determination means 103, an output means 104, an original image storage means 105, and the like.

[0023] Of the main components constituting the construction joint surface treatment determination system 100, the smoothing processing means 101, aggregate extraction means 102, and treatment degree determination means 103 can be manufactured as dedicated units, or a general-purpose computer device can be used. This computer device is equipped with a processor such as a CPU, memories such as ROM and RAM, input means such as a mouse and keyboard, and a display, and can be configured as a personal computer (PC), a tablet PC such as an iPad (registered trademark), or a mobile terminal including a smartphone. The output means 104 is a device that outputs images, such as a display or printer, and can be, for example, the display of a personal computer.

[0024] One feature of the present invention is the use of an image (hereinafter referred to as the "original image") of a concrete surface (i.e., a concrete joint surface) after a pouring joint treatment such as green cut has been performed on the concrete surface. The original image can be taken by a person (e.g., a worker), by a digital camera or digital video mounted on a mobile cart, or by a digital camera mounted on a UAV (Unmanned Aerial Vehicle). The original image storage means 105 stores the original image and can be a storage device of a general-purpose computer or can be built on a database server. When built on a database server, it can be placed on a local network (LAN) or can be a cloud server that stores the image via the Internet.

[0025] Below, each of the main elements that make up the construction joint surface treatment determination system 100 will be explained in detail.

[0026] (Smoothing processing means) The smoothing processing means 101 is a means for generating a "first smoothed image" and a "second smoothed image" by smoothing the original image read from the original image storage means 105 (Fig. 1). The smoothing processing here is a process executed for the purpose of clarifying a target object in the image or removing noise in the image, and examples of such methods include median filter processing, averaging filter, weighted average filter, and Gaussian filter. Construction joint surface treatment determination system 100 In this case, various conventional methods such as the smoothing process can be employed.

[0027] Median filtering, a type of smoothing process, involves setting up a filter (also called a kernel) as shown in Figure 2 and converting the "pixel value" of each pixel while moving the filter. Here, pixel values ​​refer to values ​​such as grayscales representing shades of gray, color information such as RGB or CMYK, or a combination of grayscale and color information, i.e., physical property values ​​that form the basis of rendering. This median filtering process is characterized by extracting the median pixel value (hereinafter referred to as the "median pixel value") of the pixels contained within the filter, and this median pixel value is assigned to a specific pixel within the filter (e.g., the pixel at the center of the filter). For example, in the case of Figure 2, the filter contains nine pixels (Nos. 23-25, 33-35, and 43-45). The median pixel value is calculated from these nine pixel values, and the original pixel of the pixel at the center of the filter (No. 34) is converted to this median pixel value. In median filtering, pixel values ​​after conversion are determined from pixel values ​​within the filter, so naturally the image after smoothing processing will differ depending on the size of the filter (hereinafter referred to as "filter size").

[0028] The first smoothed image is an image obtained by performing a smoothing process to emphasize aggregates contained in the original image. On the other hand, the second smoothed image is an image obtained by performing a smoothing process to de-emphasize aggregates contained in the original image, in other words, to make the entire image closer to the background color of the original image. Therefore, the first smoothed image can be said to be an image generated by a smoothing process to emphasize aggregates more than the second smoothed image. For example, when median filter processing is used as the smoothing process, the first smoothed image and the second smoothed image can be generated by changing the filter size. More specifically, if the filter used to generate the first smoothed image is referred to as the "first filter" and the filter used to generate the second smoothed image is referred to as the "second filter," the smoothing processing means 101 generates the first smoothed image using the first filter with a filter size smaller than the second filter, and generates the second smoothed image using the second filter with a filter size larger than the first filter.

[0029] The smoothing processing means 101 performs smoothing processing to extract aggregates (particularly coarse aggregates) from the original image, as described below. Concrete contains coarse aggregates of various diameters. On the other hand, when determining the quality of the construction joint surface treatment, it is not necessary to extract extremely small (or large) diameter coarse aggregates. In other words, it may be sufficient to extract coarse aggregates of diameters within a predetermined range (e.g., 5 to 20 mm). Therefore, it is conceivable to set the filter sizes of the first filter and the second filter according to the minimum diameter (e.g., 5 mm) and maximum diameter (e.g., 20 mm) of the coarse aggregates to be extracted. The inventors have found that coarse aggregates can be extracted more clearly by setting the filter size of the first filter so as to encompass the smallest diameter coarse aggregates to be extracted, and by setting the filter size of the second filter so as to encompass the largest diameter coarse aggregates to be extracted. Specifically, the filter size (i.e., the number of pixels it comprises) is set by dividing the projected area of ​​the smallest diameter coarse aggregate by the resolution (area of ​​one pixel), and the filter size is set by dividing the projected area of ​​the largest diameter coarse aggregate by the resolution and multiplying it by a predetermined multiplier (for example, 1.5 times).

[0030] The smoothing processing means 101 can perform smoothing processing on each original image to generate a first smoothed image and a second smoothed image, can perform smoothing processing on a composite image made by stitching together multiple original images to generate a first smoothed image and a second smoothed image, or can perform smoothing processing on an orthogonally transformed image (orthoimage) made up of multiple original images to generate a first smoothed image and a second smoothed image.

[0031] (Aggregate Extraction Means) The aggregate extraction means 102 is a means for calculating the difference in pixel values ​​between the first smoothed image and the second smoothed image (hereinafter simply referred to as "pixel value difference"), and extracting the portion where this pixel value difference exceeds a predetermined threshold value (hereinafter simply referred to as "aggregate threshold value") as "a portion where aggregate (particularly coarse aggregate) is photographed (hereinafter simply referred to as "aggregate portion")" (Fig. 1). When calculating the pixel value difference, it is of course necessary to compare the pixel of the first smoothed image with the pixel of the second smoothed image corresponding to that pixel, in other words, the pixels located at the same position in each image, and then calculate the difference in pixel value. The pixel value difference can be calculated as a value with positive or negative values, or as an absolute value. In addition, all the pixels constituting the image are compared. relating to By calculating the pixel value difference, it is also possible to generate an image based on the pixel value difference (hereinafter referred to as a "difference image") as shown in FIG.

[0032] When the aggregate extraction means 102 generates a difference image, it compares the pixel value difference with an aggregate threshold for each pixel and extracts pixels with pixel value differences exceeding this aggregate threshold as "aggregate portions." At this time, it may be configured to extract aggregate portions on a pixel-by-pixel basis, or to extract portions where a cluster of a predetermined number of pixels or more is formed as an aggregate portion, or to correct and extract pixels that are not determined to be aggregate portions surrounded by pixels determined to be aggregate portions. Furthermore, the aggregate extraction means 102 does not necessarily need to generate a difference image (although it may, of course), and may instead extract aggregate portions based only on the calculated pixel value differences.

[0033] To properly extract aggregate portions, a reference aggregate threshold is important. This aggregate threshold can be set empirically or after conducting test construction. It can also be set separately for cases where the concrete surface is dry and cases where it is wet. It can also be set differently depending on the shooting conditions (e.g., sunny days and cloudy days) and the concrete mix (particularly the type of cement and coarse aggregate used). An example of setting the aggregate threshold after conducting test construction is described in detail below. First, a test concrete (hereinafter simply referred to as "test concrete") is constructed, and the test concrete surface is subjected to joint surface treatment, after which an image (hereinafter referred to as "index image") is obtained. Then, a first smoothed image and a second smoothed image are generated based on the index image. Subtraction images are generated while varying the aggregate threshold, and the most appropriate aggregate threshold is determined by comparing each of the subtraction images with the index image.

[0034] In this way, the aggregate portion is extracted after calculating the pixel value difference between the first smoothed image in which the aggregate is emphasized and the second smoothed image in which the background color of the original image is used, so to speak, and therefore the aggregate portion can be extracted more clearly than by judging from, for example, the first smoothed image alone. Note that the aggregate extraction means 102 can extract the aggregate portion based on the first smoothed image and the second smoothed image generated for each original image, can extract the aggregate portion based on the first smoothed image and the second smoothed image generated for a composite image obtained by stitching together a plurality of original images, or can extract the aggregate portion based on the first smoothed image and the second smoothed image generated for an orthogonal transformed image (orthoimage) made up of a plurality of original images.

[0035] (Processing level determination means) When the aggregate portion is extracted by the aggregate extraction means 102, the proportion of the aggregate portion in the range of the concrete surface corresponding to the original image (hereinafter referred to as the "target area") can be ascertained, and a person (for example, a worker) can thereby determine whether the joint surface treatment is good or bad. Alternatively, the proportion of the target area that is occupied by aggregate portions (hereinafter referred to as the "aggregate distribution proportion") can be calculated, and then the quality of the joint surface treatment can be quantitatively determined.

[0036] The processing level determination means 103 calculates the aggregate distribution ratio based on the area (or total number of pixels) of the difference image (or the original image) and the area (or number of pixels) of the aggregate portion, and determines the degree of construction joint surface processing in the target area (hereinafter simply referred to as the "construction joint surface processing level") by comparing the aggregate distribution ratio with a predetermined threshold (hereinafter referred to as the "processing level threshold") (Figure 1). Specifically, the aggregate distribution ratio is calculated by dividing the area of ​​the aggregate portion by the area of ​​the difference image, and the construction joint surface processing level is determined by comparing the aggregate distribution ratio with the processing level threshold. For example, if the processing level threshold is set as the boundary between "insufficient construction joint surface processing" and "good construction joint surface processing," the construction joint surface processing level is determined to be "insufficient" when the aggregate distribution ratio is below the processing level threshold, and conversely, the construction joint surface processing level is determined to be "good" when the aggregate distribution ratio is above the processing level threshold. Alternatively, if a processing level threshold is set as the boundary between "good construction joint surface" and "over-processed construction joint surface," the processing level of the construction joint surface is judged to be "good" when the aggregate distribution ratio is below the processing level threshold, and conversely, if the aggregate distribution ratio is above the processing level threshold, the processing level of the construction joint surface is judged to be "over-processed." Of course, it is also possible to set two or more processing level thresholds in advance, such as setting a first processing level threshold as the boundary between "insufficient construction joint surface treatment" and "good construction joint surface," and a second processing level threshold as the boundary between "good construction joint surface" and "over-processed construction joint surface," thereby allowing the processing level of the construction joint surface to be judged in three or more stages (for example, "insufficient," "good," "over-processed," etc.).

[0037] The processing level determination means 103 can calculate the aggregate distribution ratio for each original image (for example, by treating the difference image as one unit) and determine the degree of construction joint surface processing, or it can calculate the aggregate distribution ratio for each region (hereinafter referred to as "division target region") obtained by dividing the original image (or the difference image) as shown in Figure 4 and determine the degree of construction joint surface processing. Specifically, the aggregate distribution ratio for a division target region is calculated by dividing the area of ​​the aggregate portion included in the division target region by the area of ​​the division target region. For example, in Figure 4, six division target regions are formed by dividing the difference image, and in this case the processing level determination means 103 calculates the aggregate distribution ratio for each of the six division target regions and determines the degree of construction joint surface processing for each of them.

[0038] To properly determine the degree of concrete joint treatment, a standard treatment threshold is essential. Like the aggregate threshold, this treatment threshold can be set empirically or after conducting test construction. It can also be set separately for cases where the concrete surface is dry and cases where it is wet. It is also possible to set different aggregate thresholds depending on the imaging conditions and concrete mix. An example of setting the aggregate threshold after test construction is described in detail below. First, test concrete is constructed, and the test concrete surface is treated with a treatment. At this time, the treatment is performed to achieve different degrees of treatment, such as "insufficient treatment," "good treatment," or "over-treatment," i.e., multiple test pieces are prepared. Then, index images are acquired for each test piece. A difference image is generated based on each index image, and the aggregate distribution ratio is calculated. An appropriate treatment threshold is set according to the degree of treatment of the concrete joint in the difference image. For example, by checking the index image, it is possible to identify the area where the "placement joint surface is good," extract the aggregate distribution ratio for the division target area corresponding to that area, and then set the upper and lower limits of the aggregate distribution ratio for which the "placement joint surface is good" as the treatment level threshold. Note that by constructing multiple (here, n pieces) test concretes and performing multiple stages (here, m stages) of placement joint surface treatment level processing, multiple (n x m) test pieces are prepared (i.e., n x m index images are obtained), and then setting the treatment level threshold, it is possible to set a treatment level threshold that is more suited to the current situation, which is preferable.

[0039] (Processing flow) With reference to Figure 5 Construction joint surface treatment determination system 100 This section explains the main processing flow when using the system. Figure 5 is a flow chart showing the main processing flow of the construction joint surface treatment determination system 100, with the central column showing the processing to be performed, the left column showing the input information required for that processing, and the right column showing the output information resulting from that processing.

[0040] When a concrete surface that has hardened to some extent is subjected to a pouring joint surface treatment, the concrete surface is photographed using, for example, a digital camera mounted on a UAV to obtain an original image (Step 101 in Fig. 5). When the original image is stored in the original image storage means 105 (Fig. 1), the smoothing processing means 101 reads the original image and performs a smoothing process such as a median filter process on the original image to generate a first smoothed image and a second smoothed image (Step 102 in Fig. 5).

[0041] When the first smoothed image and the second smoothed image are generated, the aggregate extraction means 102 calculates the pixel value difference to generate a difference image (Step 103 in Fig. 5), and compares the pixel value difference with an aggregate threshold to generate an image in which the aggregate portion is extracted (hereinafter referred to as an "aggregate distribution image") (Step 104 in Fig. 5). When the aggregate distribution image is generated, the processing level determination means 103 sets regions to be divided (Step 105 in Fig. 5), and calculates the aggregate distribution ratio for each region to be divided based on the area of ​​the difference image (the difference image of the region to be divided) and the area of ​​the aggregate portion (the aggregate portion included in the region to be divided) (Step 106 in Fig. 5), and further determines the degree of processing of the pour joint surface for each region to be divided by comparing the aggregate distribution ratio with the processing level threshold (Step 107 in Fig. 5).

[0042] As mentioned above, the aggregate threshold and treatment level threshold can be set by conducting test construction, and in this case, the construction joint surface treatment determination system 100 can be used. Figure 6 is a flow diagram showing the main processing flow up to determining the aggregate threshold and treatment level threshold among the processing of the construction joint surface treatment determination system 100, with the center column showing the processing to be performed, the left column showing the input information required for that processing, and the right column showing the output information resulting from that processing. Below, with reference to Figure 6, the processing flow up to setting the aggregate threshold and treatment level threshold using the construction joint surface treatment determination system 100 will be explained.

[0043] First, a test concrete is constructed, and a construction joint surface treatment is performed on the surface of the test concrete. At this time, the construction joint surface treatment is performed to achieve different degrees of construction joint surface treatment, such as "insufficient construction joint surface treatment," "good construction joint surface treatment," and "over-treated construction joint surface treatment." In other words, multiple types of test pieces are prepared. Once multiple types of test pieces are prepared, an index image is acquired for each test piece (Step 111 in FIG. 6). Once the index image is stored in the original image storage means 105, the smoothing processing means 101 reads out the index image and performs a smoothing process, such as median filter processing, on the index image to generate a first smoothed image (hereinafter, specifically referred to as the "first smoothed index image") and a second smoothed image (hereinafter, specifically referred to as the "second smoothed index image") (Step 102 in FIG. 6).

[0044] After the first smoothed index image and the second smoothed index image are generated, the aggregate extraction means 102 calculates the pixel value difference to generate a difference image (hereinafter, specifically referred to as a "difference index image") (Step 103 in FIG. 6). Next, a provisionally determined aggregate threshold (hereinafter, simply referred to as a "provisional aggregate threshold") is input by the operator (Step 112 in FIG. 6), and the aggregate extraction means 102 compares the difference index image with the provisional aggregate threshold to generate an image in which the aggregate portion has been provisionally extracted (hereinafter, referred to as a "provisional aggregate distribution image") (Step 104 in FIG. 6). Then, the provisional aggregate distribution image is compared with the index image, and if it is determined that the aggregate distribution roughly matches (Yes in Step 113 in Figure 6), the process proceeds to the subsequent processing. If it is determined that the aggregate distribution does not match (No in Step 113 in Figure 6), a different provisional aggregate threshold is set (Step 112 in Figure 6) and the specified processing (Steps 104 to 113 in Figure 6) is repeatedly executed.

[0045] Once the aggregate threshold is officially determined (Step 114 in FIG. 6), the aggregate extraction means 102 calculates pixel value differences again and generates difference images based on the index images acquired for each degree of concrete joint surface treatment, as well as an aggregate distribution image (Step 104 in FIG. 6). Once the aggregate distribution image is generated for each index image, the treatment level determination means 103 sets each target region for division and calculates the aggregate distribution ratio for each target region for division based on the area of ​​the difference image and the area of ​​the aggregate portion (Step 106 in FIG. 6). An appropriate treatment level threshold is then set according to the degree of concrete joint surface treatment associated with the difference image (Step 115 in FIG. 6).

[0046] 2. Method for determining joint surface treatment Next, the construction joint surface treatment determination method of the present invention will be explained with reference to Figure 7. The construction joint surface treatment determination method of the present invention is a method for determining the quality of construction joint surface treatment using the construction joint surface treatment determination system 100 explained so far, and therefore we will avoid overlapping explanations with those explained in the construction joint surface treatment determination system 100 and will only explain the details unique to the construction joint surface treatment determination method of the present invention. In other words, the details not described here are the same as those explained in "1. Construction joint surface treatment determination system."

[0047] As shown in Figure 7, the method for determining construction joint surface treatment of the present invention can be broadly divided into "trial construction" and "actual construction," enclosed by dashed lines. As explained above, the trial construction is a process carried out to set the aggregate threshold and treatment level threshold. Therefore, if the aggregate threshold and treatment level threshold have already been obtained, the method for determining construction joint surface treatment can be carried out without trial construction. However, for convenience, an example including trial construction will be explained here.

[0048] (Test construction) First, a test concrete is constructed, and a construction joint surface treatment is performed on the surface of the test concrete (Step 211 in FIG. 7). At this time, the construction joint surface treatment is performed to achieve different degrees of construction joint surface treatment, for example, "insufficient construction joint surface treatment," "good construction joint surface," or "over-treated construction joint surface." In other words, multiple types of test pieces are prepared. Once multiple types of test pieces are prepared, an index image is acquired for each test piece (Step 212 in FIG. 7). Once the index image is acquired, a smoothing process (e.g., median filter process) is performed on the index image using the smoothing process means 101 to generate a first smoothed index image and a second smoothed index image (Step 213 in FIG. 7). After the first smoothed index image and the second smoothed index image are generated, the aggregate extraction means 102 is used to generate a difference index image (Step 214 in FIG. 7). Furthermore, the aggregate extraction means 102 is used to generate provisional aggregate distribution images while varying the provisional aggregate threshold value, and the provisional aggregate distribution image is compared with the index image to determine the aggregate threshold value (Step 215 in FIG. 7). Once the aggregate threshold value is officially determined, the aggregate extraction means 102 is used to generate a difference image based on the index image for each degree of construction joint surface treatment, and an aggregate distribution image is also generated. Then, the treatment degree determination means 103 is used to calculate the aggregate distribution ratio for each region to be divided, and an appropriate treatment degree threshold value is set (Step 215 in FIG. 7).

[0049] (Implementation work) First, concrete to be actually constructed (hereinafter referred to as "permanent concrete") is constructed, and a pouring joint surface treatment is performed on the surface of the permanent concrete (Step 221 in FIG. 7). Then, an original image is obtained by photographing the surface of the permanent concrete that has undergone pouring joint surface treatment (Step 222 in FIG. 7). After the original image is obtained, the smoothing processing means 101 performs a smoothing process (e.g., median filter processing) on ​​the original image to generate a first smoothed image and a second smoothed image (Step 223 in FIG. 7). After the first smoothed image and the second smoothed image are generated, the aggregate extraction means 102 generates a difference image (Step 224 in FIG. 7). Further, the aggregate extraction means 102 extracts the aggregate portion to generate an aggregate distribution image (Step 225 in FIG. 7). After the aggregate distribution image is generated, the processing degree determination means 103 calculates the aggregate distribution ratio for each division target region (Step 226 in FIG. 7) and determines the pouring joint surface treatment degree for each division target region (Step 227 in FIG. 7).

[0050] 3. Experimental Results The inventors of the present invention conducted an experiment to determine the quality of the construction joint surface treatment using the present invention. Figure 8 is a model diagram showing the results of determining the degree of construction joint surface treatment of a concrete surface using the construction joint surface treatment determination system 100, where (a) is the result of an experiment conducted specifically for a dry concrete surface, and (b) is the result of an experiment conducted specifically for a wet concrete surface. In this experiment, test pieces with "insufficient" construction joint surface treatment, test pieces with "good" treatment, and test pieces with "over-treated" treatment were used.

[0051] As can be seen from Figure 8, when the original image of a test piece rated "insufficient" is processed by the construction joint surface treatment determination system 100, a relatively large number of segmentation target areas with an "insufficient" degree of construction joint surface treatment are output; when the original image of a test piece rated "good" is processed by the construction joint surface treatment determination system 100, a relatively large number of segmentation target areas with a "good" degree of construction joint surface treatment are output; and when the original image of a test piece rated "overtreated" is processed by the construction joint surface treatment determination system 100, a relatively large number of segmentation target areas with an "overtreated" degree of construction joint surface treatment are output. Furthermore, the results processed by the construction joint surface treatment determination system 100 generally match the actual condition, regardless of the condition of the concrete surface (whether dry or wet). In this way, the present invention can extremely effectively determine the quality of construction joint surface treatment. [Industrial Applicability]

[0052] Method for determining joint surface treatment of the present invention can be used in various concrete structures, including civil engineering structures such as dams, tunnels, and bridges, and architectural structures such as apartment buildings and office buildings. Considering that the present invention can build concrete structures with excellent mechanical performance, durability, watertightness, and appearance by realizing appropriate joint surface treatment, in other words, providing high-quality infrastructure, it can be said to be an invention that can be expected to not only be used industrially but also make a significant contribution to society. [Explanation of symbols]

[0053] 100 Construction joint surface treatment judgment system 101 (Concrete joint surface treatment judgment system) smoothing processing means 102 Aggregate extraction means (for the construction joint surface treatment judgment system) 103 (of the construction joint surface treatment determination system) treatment degree determination means 104 (of the construction joint surface treatment judgment system) output means 105 (of the construction joint surface treatment judgment system) original image storage means

Claims

1. A method for determining the quality of concrete joint surface treatment based on an original image of the concrete surface, comprising: an original image acquisition step of performing a joint surface treatment on the surface of the concrete, photographing the surface of the concrete to acquire the original image, and smoothing the original image to generate a first smoothed image and a second smoothed image; an aggregate extraction step of calculating a pixel value difference between the first smoothed image and the second smoothed image, and extracting a portion where the pixel value difference exceeds an aggregate threshold as an aggregate portion, the first smoothed image is an image generated by smoothing processing so that aggregates are more emphasized than in the second smoothed image, determining whether the joint surface treatment is good or bad based on the proportion of the aggregate portion occupying the target area corresponding to the original image; A method for determining joint surface treatment.

2. The method further comprises a process of determining the degree of treatment of the joint surface in the target area by calculating the aggregate distribution ratio of the aggregate portion in the target area and comparing the aggregate distribution ratio with a treatment degree threshold. The method for determining joint surface treatment according to claim 1.

3. By setting the processing degree threshold value to 2 or more in stages in advance, the processing degree of the joint surface, which indicates the degree of processing of the joint surface, is set to 3 or more stages, In the treatment degree determination step, the aggregate distribution ratio is compared with two or more of the treatment degree thresholds to determine the treatment degree of the joint surface in the target area. The method for determining joint surface treatment according to claim 2.

4. In the original image acquisition process, an operator photographs the surface of the concrete using a photographing means of a tablet PC. The method for determining joint surface treatment according to any one of claims 1 to 3.

Images