How to determine the green cut criteria

Abstract

This invention provides a method for determining green cut quality standards that can reduce variations in the judgment regarding the finished state of the green cut surface. [Solution] The method for determining the green cut standard comprises: a specimen preparation step of preparing multiple specimens that simulate concrete used at construction sites, wherein the finished state of the green cut surface of the specimens, which is the joint surface where the green cut has been performed, differs from one another; an image data acquisition step of acquiring image data of the multiple specimen green cut surfaces; and a quality standard determination step of determining an identification specimen green cut surface for identifying green cut surfaces that meet the quality standard and those that do not from among the multiple specimen green cut surfaces captured in the image data.

Description

Technical Field

[0001] The present disclosure relates to a method for determining green cut quality standards for determining quality standards for the finish state of the green cut surface of concrete placed at a construction site.

Background Art

[0002] Conventionally, when constructing concrete structures such as dam embankments, concrete joints have been made. Jointing is a construction method in which the previously placed concrete is hardened and the process of placing new concrete on the joint surface is repeated.

[0003] In order to strengthen the joint part between two concretes placed with a time interval, it is necessary to remove the insufficiently hardened concrete formed on the placement surface of the previously placed concrete before placing the new concrete. The operation of shaving the joint surface for the purpose of removing this insufficiently hardened concrete is called green cut. In Patent Document 1, green cut is executed by a green cut machine that automatically travels on the joint surface.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The better the finish state of the green cut surface, which is the joint surface after green cut, the stronger the joint part is joined, so the strength of the overlaid concrete is improved. Generally, it is said that green cut is preferably carried out to the extent that the surface of the coarse aggregate in the concrete is exposed.

[0006] The determination of whether the finish of the green cut surface is satisfactory is made by construction site supervisors based on their experience, but this determination relies on the supervisor's experience and intuition, which can lead to inconsistent results. If the supervisor judges the finish to be unsatisfactory even though it is actually satisfactory, further green cutting will be required, increasing the workload at the construction site.

[0007] This disclosure has been made in view of the above-mentioned problems, and aims to provide a method for determining green cut quality standards that can suppress variations in the judgment of the finished state of the green cut surface. [Means for solving the problem]

[0008] 1) A method for determining green cut criteria according to at least one embodiment of this disclosure is: A method for determining green cut standards, which determines the quality standards that should be met at a construction site for the finished state of the green cut surface, which is the concrete joint surface where green cut has been performed. A specimen preparation step involves preparing multiple specimens that simulate the concrete used at the aforementioned construction site, wherein the green-cut surfaces of the specimens, which are the construction joint surfaces where the green cuts have been made, are all different in their finished state. Image data acquisition step of acquiring image data of multiple green cut surfaces of the test specimens, A quality standard determination step for determining an identification test specimen green cut surface to distinguish between the green cut surfaces that meet the quality standard and those that do not, from among the multiple test specimen green cut surfaces captured in the image data, It is equipped with.

[0009] According to the above configuration, the green cut surface of an identification specimen, selected from multiple green cut surfaces shown in the image, becomes the standard for judging the quality of the finished green cut surface at the construction site. The judge at the construction site can refer to the green cut surface of the identification specimen as needed to determine whether the actual green cut surface meets the quality standards, thus reducing variability in judgments regarding the finished state of the green cut surface.

[0010] 2) In some embodiments, the method for determining the green cut criteria described in 1) above is The system further comprises a strength acquisition step of acquiring the strength of multiple jointed test specimens formed by pouring the concrete onto each of the multiple test specimen green cut surfaces, In the quality standard determination step, the multiple green cut surfaces of the test specimens shown in the image are associated with the acquired strength, and the green cut surface of the test specimen having a predetermined strength is determined as the green cut surface of the identification test specimen.

[0011] According to the above configuration, a green cut surface of a test specimen with a predetermined strength can be determined as the green cut surface of an identification test specimen. This increases the reliability of the green cut surface of the identification test specimen, which serves as a criterion for judging the quality of the finished green cut surface.

[0012] 3) In some embodiments, the method for determining the green cut criteria described in 2) above, The strength acquisition step includes a shear strength acquisition step for acquiring the shear strength of the jointed test specimen.

[0013] According to the above configuration, the green cut surface of a test specimen having a predetermined shear strength can be used as a criterion for judging the quality of the finished green cut surface.

[0014] 4) In some embodiments, a method for determining the green cut criteria as described in 2) or 3) above, The strength acquisition step includes a compressive strength acquisition step for acquiring the compressive strength of the jointed test specimen.

[0015] According to the above configuration, the green cut surface of a test specimen having a predetermined compressive strength can be used as a criterion for judging the quality of the finished green cut surface.

[0016] 5) In some embodiments, the method for determining the green cut criteria described in any of 1) to 4) above is: The system further comprises a step of obtaining a permeability value, which involves performing a permeability test on the jointed specimen to obtain a permeability value indicating the permeability of the jointed specimen. In the quality standard determination step, the green cut surfaces of the multiple test specimens shown in the image are associated with the permeability values, and the green cut surface of the test specimen having a predetermined watertightness is determined as the green cut surface of the identification test specimen.

[0017] According to the above configuration, a watertight green-cut surface of the specimen can be designated as the green-cut surface for identification. This increases the reliability of the green-cut surface for identification, which serves as a criterion for judging the quality of the finished green-cut surface.

[0018] 6) In some embodiments, the method for determining the green cut criteria described in any of 1) to 5) above is: A sample image data preparation step involves preparing sample image data of a sample green cut surface, which is a construction joint surface where the green cut has been performed, from among a plurality of concrete samples that simulate the aforementioned concrete. A judgment model creation step involves creating a judgment model based on the sample image data, which is configured to determine whether the green cut surface captured in the image taken at the construction site meets the quality standards. To further prepare.

[0019] According to the above configuration, it is determined whether the green cut surface at the construction site meets the quality standard by using the determination model. As a result, it is possible to further suppress the variation in the determination of the finished state of the green cut surface at the construction site.

Effect of the Invention

[0020] According to the present disclosure, a method for determining a green cut quality standard that can suppress variations in the determination of the finished state of the green cut surface is provided.

Brief Description of the Drawings

[0021] [Figure 1] It is a schematic diagram showing a construction site of a concrete structure. [Figure 2] It is a schematic diagram of a plurality of test specimens. [Figure 3] It is a schematic diagram of a data table according to the first embodiment. [Figure 4] It is a flowchart of a method for determining a green cut standard according to the first embodiment. [Figure 5] It is a flowchart of a method for determining a green cut standard according to the second embodiment. [Figure 6] It is a schematic diagram of a plurality of joint test specimens. [Figure 7] It is a flowchart of the strength acquisition step. [Figure 8] It is a schematic diagram of a data table according to the second embodiment. [Figure 9] It is a flowchart of a method for determining a green cut standard according to the third embodiment. [Figure 10] It is a schematic diagram of a plurality of concrete samples. [Figure 11] It is a schematic diagram of teacher data and a determination model.

Modes for Carrying Out the Invention

[0022] Hereinafter, several embodiments of this disclosure will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described or shown in the drawings as embodiments are not intended to limit the scope of this disclosure, but are merely illustrative examples. For example, expressions describing relative or absolute arrangements such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" should not only strictly describe such arrangements, but also describe states of relative displacement with tolerances or angles or distances that allow for the same function to be achieved. For example, expressions such as "identical," "equal," and "homogeneous" that describe things being in an equal state not only describe a state of being strictly equal, but also describe a state in which there is a tolerance or a difference that is sufficient to achieve the same function. For example, expressions describing shapes such as squares or cylinders shall not only represent geometrically precise shapes such as squares or cylinders, but also shapes that include protrusions, chamfers, etc., to the extent that the same effect can be achieved. On the other hand, expressions such as "possessing," "including," or "having" one component are not exclusive expressions that exclude the existence of other components. Note that similar configurations may be denoted by the same reference numerals and their explanations may be omitted.

[0023] <Overview> Figure 1 is a schematic diagram showing a construction site for a concrete structure 1, such as a dam embankment. The concrete 3 that makes up the concrete structure 1 includes a green-cut surface 4, which is a horizontal construction joint surface where green-cutting has been performed. A supervisor 9 at the construction site determines whether the finished state of the green-cut surface 4 meets predetermined quality standards. If it is determined that the quality standards are met, new concrete 3 is poured onto the green-cut surface 4; otherwise, further green-cutting is performed on the green-cut surface 4.

[0024] Previously, there was a problem in that the judgments of the judges 9, who had to rely on their own experience and intuition, were inconsistent. The inventors of this invention believed that if this inconsistency could be suppressed, it would be possible to eliminate the additional green cuts that were being performed unnecessarily, thereby reducing the workload at construction sites.

[0025] Based on the above concept, the inventor of this invention devised a method for determining the green cut standard. This method determines the standard (quality standard) for the finished state of the green cut surface 4 that should be met at the construction site.

[0026] More specifically, multiple test specimens 5 (see Figure 2) are prepared, simulating the concrete 3 used at the construction site. Each test specimen 5 includes a test specimen green-cut surface 6 (see Figure 2), which is a horizontal construction joint surface where green-cutting has been performed. From among the multiple test specimen green-cut surfaces 6, one test specimen green-cut surface 6 is selected to be used as a criterion for determining whether the green-cut surface 4 at the site meets the quality standards. This test specimen green-cut surface 6 is one that should be judged to have a good green-cut finish at the site. The above selection is made through consultations between the construction company and the client before the start of construction. At that time, an image of the test specimen green-cut surface 6 selected as the criterion (hereinafter sometimes referred to as "identification test specimen green-cut surface 12") is saved as data.

[0027] Once construction begins at the construction site, the evaluator 9 checks images of the green cut surface 12 of the identification test specimen, which have been predetermined through consultation, on a portable terminal 8, for example, to determine (identify) the quality of the actual green cut surface 4. This helps to reduce variations in the evaluation by the evaluator 9.

[0028] The method for determining the green cut criteria related to this disclosure will be described in detail below, divided into the first embodiment, the second embodiment, and the third embodiment.

[0029] <First Embodiment> Figure 2 is a schematic diagram of multiple test specimens 5. Figure 3 is a schematic diagram of image data 7 obtained from multiple test specimens 5. Figure 4 is a flowchart of the method for determining the green cut criterion according to the first embodiment. In the following description, "step" may be abbreviated as "S".

[0030] As shown in Figure 4, the method for determining the green cut criterion comprises a specimen preparation step (S10), an image data acquisition step (S20), and a quality criterion determination step (S60).

[0031] Referring to Figure 2, the specimen preparation step (S10) is explained. In S10, multiple specimens 5 are prepared, simulating concrete 3 (see Figure 1) used at construction sites. Specimens 5 are cylindrical bodies made of the same material as concrete 3. The green cut finish on the green cut surface 6 of the specimens differs among the multiple specimens 5. Note that the difference in the finish between the multiple specimens 5 is such that it can be distinguished by visual inspection by a person.

[0032] In this example, four types of test specimens 5A, 5B, 5C, and 5D (5) are prepared, and the finished state differs among the green cut surfaces 6A, 6B, 6C, and 6D (6) of these specimens. The number of types of test specimens 5 prepared is not limited to four; there is no problem with using three types or five or more types.

[0033] Referring to Figures 2 and 3, the image data acquisition step (S20) will be explained. In S20, image data 7 of the green cut surfaces 6 of multiple test specimens 5 are acquired. More specifically, four types of green cut surfaces 6A, 6B, 6C, and 6D (6) of the test specimens are photographed by the imaging device 11. As a result, image data 7A, 7B, 7C, and 7D (7) are generated, each showing an image of the green cut surfaces 6A, 6B, 6C, and 6D of the test specimens. In this example, a data table 14 is created that associates the image data 7 with the classification numbers of the test specimens 5, and is stored in a computer device such as a PC, tablet, or smartphone.

[0034] In the example shown in Figure 3, one of the green cut surfaces 6A, 6B, 6C, or 6D of the specimen is captured in a single image, but the disclosure is not limited to this. For example, there is no problem if all four types of green cut surfaces 6A, 6B, 6C, and 6D of the specimen are captured in a single image.

[0035] Referring to Figure 3, the quality standard determination step (S60) will be explained. In S30, an identification test specimen green cut surface 12 is determined from among the multiple test specimen green cut surfaces 6 captured in the image data 7 to distinguish between green cut surfaces 4 that meet the quality standard and those that do not.

[0036] More specifically, the construction contractor prepares the above data table 14 in advance and presents it to the client when they receive a request for construction work. Upon receiving the table, the client determines the identification green cut surface 12 from among the green cut surfaces 6A, 6B, 6C, and 6D of the test specimens shown in the image. This determination is preferably made through consultation between the client and the construction contractor.

[0037] In this example, the green cut surface 6B of the specimen corresponding to classification "2" is determined to be the green cut surface 12 of the specimen used for identification. The image data 7B of the green cut surface 6B of the specimen is stored in the terminal 8 used by the evaluator 9 at the construction site. The evaluator 9 can determine (identify) whether the actual green cut surface 4 meets the quality standards by checking the green cut surface 12 of the specimen used for identification (green cut surface 6B in this example) displayed on the screen of the terminal 8.

[0038] According to the above configuration, the identification green cut surface 12 selected from multiple green cut surfaces 6 of test specimens shown in the image becomes the standard for judging the quality of the finished green cut surface 4 at the construction site. The judge 9 refers to the identification green cut surface 12 as needed to determine whether the actual green cut surface 4 meets the quality standards, thereby reducing variability in the judgment regarding the finished state of the green cut surface 4.

[0039] <Second Embodiment> Figure 5 is a flowchart showing the method for determining the green cut criteria according to the second embodiment. In this figure, the same step numbers are assigned to the same steps as in the first embodiment.

[0040] The method for determining the green cut standard according to the second embodiment further comprises, in addition to the specimen preparation step (S10) and the image data acquisition step (S20), a joint specimen preparation step (S30), a strength acquisition step (S40), a permeability value acquisition step (S50), and a quality standard determination step (S60A).

[0041] Referring to Figure 6, the joint specimen preparation step (S30) will be explained. In S30, concrete 3 (see Figure 1) is poured onto the green cut surface 6 of each of the multiple specimens 5 prepared in S10. This forms multiple joint specimens 10 from the multiple specimens 5.

[0042] More specifically, in S30, multiple jointed specimens 10A, 10B, 10C, 10D (10) are prepared from multiple specimens 5A, 5B, 5C, 5D (5) to form cylindrical specimens. As previously described, the finish of the green cut differs among the specimen green cut surfaces 6A, 6B, 6C, 6D, so the mechanical properties such as strength and permeability coefficient differ among the jointed specimens 10A, 10B, 10C, 10D. To determine these properties, strength tests and permeability tests are performed on the jointed specimens 10 (details will be described later). Therefore, multiple jointed specimens 10A, 10B, 10C, 10D are prepared for each test (that is, multiple specimens 5A, 5B, 5C, 5D are prepared in S10). For example, multiple jointed specimens 10A are prepared for various tests.

[0043] Referring to Figures 5 and 7, the strength acquisition step (S40) will be explained. In the strength acquisition step (S40), the strength of multiple jointed test specimens 10 is acquired. The strength acquisition step includes a compressive strength acquisition step (S42) and a shear strength acquisition step (S44).

[0044] In S42, the compressive strength of the jointed concrete specimen 10 is obtained based on compression tests performed on multiple jointed concrete specimens 10. The compression tests in this example are conducted in accordance with JIS A 1108:2018 "Test Method for Compressive Strength of Concrete". Through this test, the compressive strength as a measured value is determined.

[0045] Let's explain S44. The shear strength of construction joint concrete can be determined by various methods, but two methods are given as examples below.

[0046] As a first example, the estimated shear strength may be determined based on the compressive strength of the jointed specimen 10 obtained in S42. More specifically, the shear strength may be determined by multiplying the compressive strength of the jointed specimen 10 by a coefficient of approximately 0.1 to 0.2. This method is based on the technical knowledge that the shear strength of concrete 3 has a certain correlation with its compressive strength. The specific value of the coefficient is determined through various tests and the safety factor to be set. Alternatively, instead of based on the compressive strength, the estimated shear strength may be determined based on the tensile strength (or splitting tensile strength) of the jointed specimen 10. In this case, a tensile test is performed in accordance with JIS A 1113:2018 "Test method for splitting tensile strength of concrete".

[0047] As a second example, the shear strength may be determined by performing a shear test on the jointed concrete specimen 10. In this case, a single-face shear test method may be used. In this test method, for example, shear tests with different shear angles are performed on three jointed concrete specimens 10A. The horizontal shear strength of the jointed concrete specimen 10A is then determined from the relationship between the shear strength and axial force obtained from the test results. This method is explained in detail, for example, in "The Influence of Differences in Vertical Joint Treatment Methods on the Mechanical Performance of Concrete" published in Ando Hazama Research Annual Report Vol. 2 2014.

[0048] Referring to Figure 5, the step for obtaining the permeability value (S50) is explained. In S50, a permeability test is performed on the jointed test specimen 10 to obtain (measure) the permeability value indicating the permeability of the jointed test specimen 10. The permeability value is the permeability coefficient, which indicates the amount of water that flows per unit time per unit area of ​​concrete 3, and the permeability test is carried out in accordance with JIS A 1218:2020 "Method for testing the permeability of soil". Note that the permeability value may also be the infiltration depth, which indicates how much water has penetrated into the interior of the concrete 3.

[0049] Referring to Figure 8, the quality standard determination step (S60A) according to the second embodiment will be explained. In S60A, a data table 14A (see Figure 8) is prepared, which associates the image data 7 obtained in S20, the strength (compressive strength and shear strength) obtained in S40, and the permeability value obtained in S50 with the classification number of the test specimen 5.

[0050] The construction contractor presents data table 14A to the client at the time of receiving the construction work request. The client then selects a test specimen green cut surface 6 (i.e., identification test specimen green cut surface 12) from among the test specimen green cut surfaces 6A, 6B, 6C, and 6D shown in the image that has the required strength and the required watertightness. More specifically, the test specimen green cut surface 6 that has a compressive strength of 1 or greater than the first specified value, a shear strength of 2 or greater than the second specified value, and a water permeability value of 3 or less is selected as the identification test specimen green cut surface 12. In this example, test specimen green cut surface 6B, which corresponds to classification "2", is selected as the identification test specimen green cut surface 12.

[0051] According to the above configuration, a green-cut surface 6 of a test specimen having a predetermined strength can be determined as the green-cut surface 12 of an identification test specimen. More specifically, a green-cut surface 6 of a test specimen having a predetermined compressive strength and a predetermined shear strength can be used as a criterion for judging the quality of the finished green-cut surface 4 at a construction site. This increases the reliability of the green-cut surface 12 of the identification test specimen, which serves as a criterion for judging the quality of the finished green-cut surface 4.

[0052] Furthermore, by selecting a specimen green-cut surface 6 that has a predetermined watertightness, the specimen green-cut surface 6 that ensures watertightness can be determined as the identification specimen green-cut surface 12. This increases the reliability of the identification specimen green-cut surface 12, which serves as a criterion for judging the quality of the finished state of the green-cut surface 4.

[0053] <Third Embodiment> Figure 9 is a flowchart showing the method for determining the green cut criterion according to the third embodiment. In this figure, the same step numbers are assigned to the same steps as in the second embodiment. The method for determining the green cut criterion according to the third embodiment further includes a sample image data preparation step (S70) and a judgment model creation step (S80), in addition to the components of the determination method according to the second embodiment (S10, S20, S30, S40, S50, S60A).

[0054] The sample image data preparation step (S70) will be explained with reference to Figures 10 and 11. In S70, multiple concrete samples 20 are prepared, simulating concrete 3 (see Figure 1) used at a construction site. Each concrete sample 20, made of the same material as concrete 3, has a sample green-cut surface 21, which is a horizontal construction joint surface where green cutting has been performed, and the finished state of the green cutting differs among the multiple sample green-cut surfaces 21. In S70, sample image data 29 (see Figure 11), which is an image of each sample green-cut surface 21, is prepared using the imaging device 11.

[0055] Referring to Figure 11, the judgment model creation step (S80) will be explained. In S80, a judgment model 30 is created to determine whether the green cut surface 4 captured in the image using terminal 8 (see Figure 1) meets the quality standards. The judgment model 30 is, as an example, a machine learning model.

[0056] In creating the judgment model 30, training data 22 is used. The training data 22 associates the sample image data 29 prepared in S70 with the correct / incorrect data 25. Here, the correct / incorrect data 25 is data indicating whether the sample green cut surface 21 shown in the sample image data 29 has the same finish as the identification test specimen green cut surface 12 determined in S60A. The correct / incorrect data 25 may be created, for example, by a person inputting the data while checking the sample image data 29. By performing machine learning using the training data 22, the judgment model 30 that has completed machine learning is created.

[0057] The machine learning-trained judgment model 30 is configured to take image data of the green cut surface 4 captured by the terminal 8 as input data and output data indicating the result of its determination of whether the green cut surface 4 meets the quality standards. The judge 9 can make a final determination of whether the green cut surface 4 meets the quality standards by comparing the image of the green cut surface 12 of the identification specimen with the actual green cut surface 4 and by referring to the data output from the judgment model 30.

[0058] According to the above configuration, the judgment model 30 is used to determine whether the green cut surface 4 at the construction site meets the quality standards. This further reduces variations in the judgment regarding the finished state of the green cut surface 4 at the construction site. [Explanation of Symbols]

[0059] 1: Concrete structures 3: Concrete 4: Green cut surface 5A,5B,5C,5D(5):Specimen 6A, 6B, 6C, 6D(6): Green cut surface of the test specimen 7A,7B,7C,7D(7):Image data 8: Terminal 9: Judge 10A, 10B, 10C, 10D (10): Connection specimen 11: Imaging device 12: Green cut surface of the specimen for identification 14,14A: Data Table 20: Concrete sample 21: Sample green cut surface 22: Training data 25: Correct / Incorrect Data 29: Sample image data 30: Decision Model

Claims

1. A method for determining green cut standards, which determines the quality standards that should be met at a construction site for the finished state of the green cut surface, which is the concrete joint surface where green cut has been performed. A specimen preparation step involves preparing multiple specimens that simulate the concrete used at the aforementioned construction site, wherein the green-cut surfaces of the specimens, which are the construction joint surfaces where the green cuts have been made, are all different in their finished state. Image data acquisition step of acquiring image data of multiple green cut surfaces of the test specimens, A quality standard determination step for determining an identification test specimen green cut surface to distinguish between the green cut surfaces that meet the quality standard and those that do not, from among the multiple test specimen green cut surfaces captured in the image data, A method for determining green cut criteria that includes the following.

2. The system further comprises a strength acquisition step of acquiring the strength of multiple jointed test specimens formed by pouring the concrete onto each of the multiple test specimen green cut surfaces, In the quality standard determination step, the multiple green cut surfaces of the test specimens shown in the image are associated with the obtained strength, and the green cut surface of the test specimen having a predetermined strength is determined as the green cut surface of the identification test specimen. A method for determining the green cut criteria according to claim 1.

3. The strength acquisition step includes a shear strength acquisition step to acquire the shear strength of the jointed test specimen. The method for determining the green cut standard according to claim 2.

4. The strength acquisition step includes a compressive strength acquisition step to acquire the compressive strength of the jointed test specimen. A method for determining the green cut criteria according to claim 2 or 3.

5. The system further comprises a step of obtaining a permeability value, which involves performing a permeability test on the jointed specimen to obtain a permeability value indicating the permeability of the jointed specimen. In the quality standard determination step, the green cut surfaces of the multiple test specimens shown in the image are associated with the permeability values, and the green cut surface of the test specimen having a predetermined watertightness is determined as the green cut surface of the identification test specimen. A method for determining the green cut criteria according to claim 1 or 2.

6. A sample image data preparation step involves preparing sample image data of a sample green cut surface, which is a construction joint surface where the green cut has been performed, from among a plurality of concrete samples that simulate the aforementioned concrete. A judgment model creation step involves creating a judgment model based on the sample image data, which is configured to determine whether the green cut surface captured in the image taken at the construction site meets the quality standards. Furthermore, it is equipped with A method for determining the green cut criteria according to claim 1 or 2.

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