JP2021009111A - Fixing state determination device and fixing state determination method for j-shaped anchor bolt - Google Patents

Abstract

To simply and accurately determine the quality of a fixing state of a J-shaped anchor bolt embedded in concrete.SOLUTION: A fixing state determination device 1 for a J-type anchor bolt comprises: an ultrasonic probe 9 that is responsible for transmitting ultrasonic waves and receiving received waves, and is in contact with a protruding end 14 of a J-type anchor bolt 10 embedded in a concrete structure 100; a fixing state determination unit 21 that captures the received waves from the ultrasonic probe 9, and depending on whether received signals of the received waves include tip reflected signals of tip reflected waves that the transmitted ultrasonic waves are reflected at a boundary B near the tip of a shaft part 11 of the J-type anchor bolt 10, determines the quality of a fixing state; and an output unit 5 that outputs the determination result of the fixing state determination unit 21.SELECTED DRAWING: Figure 2

Description

The present invention relates to a fixing state determining device and a fixing state determining method for determining the quality of the fixed state of J-type anchor bolts embedded in a concrete structure.

Normally, when fixtures such as equipment are attached to concrete, anchor bolts for attachment are embedded in the base concrete and regularly inspected whether they are firmly fixed, including immediately after construction. I need to go. To confirm the embedding length of a straight anchor bolt immediately after construction in a concrete structure, apply the standard JIS-Z-2355 "Thickness measurement method by ultrasonic pulse reflection method" and apply the ultrasonic thickness. It is possible to perform non-destructive inspection with a measuring device.

Further, as a method capable of determining the anchor bolt fixing state, in Patent Document 1, in Patent Document 1, the fundamental frequency of the burst wave of ultrasonic waves is changed for each burst wave pulse transmission / reception cycle, and a plurality of frequency response minute reflection reception signals are applied to concrete. A method for detecting the fixed state and corrosion state of buried anchor bolts has been proposed. Further, Patent Document 2 proposes a method of detecting corrosion of a reinforcing bar from a reference value of a red rust generation state of the reinforcing bar.

Japanese Patent No. 5397969 Japanese Unexamined Patent Publication No. 2019-15655

By the way, in the measurement method by JIS-Z-2355 "Thickness measurement method by ultrasonic pulse reflection method", it is possible to measure the embedding length of a straight anchor bolt itself based on the propagation time of ultrasonic waves. However, when the anchor bolt is a J-type anchor bolt, it is not suitable for determining the fixed state of the J-type anchor bolt embedded in concrete.

Further, in a concrete structure in which J-type anchor bolts and reinforcing bars are arranged, when the method of Patent Document 2 is used to determine the fixing state of J-type anchor bolts, a plurality of J-type anchor bolts and reinforcing bars are buffered. Since the minute reflection reception signal of the frequency response shows various aspects, it is not possible to judge whether the J-type anchor bolt is in a poor fixing state, the reinforcing bar is in a poor fixing state, or other situations. It ends up. Therefore, there is a demand for a method capable of accurately determining the quality of the fixed state of J-type anchor bolts embedded in concrete.

The present invention has been proposed in view of the above problems, and is a fixing state determination device for J-type anchor bolts and a fixing state determination that can easily and accurately determine the quality of the fixing state of J-type anchor bolts embedded in concrete. The purpose is to provide a method.

The fixing state determination device for J-type anchor bolts of the present invention is a fixing state determination device for determining whether the fixing state of J-type anchor bolts embedded in a concrete structure is good or bad, and transmits ultrasonic waves and receives received waves. The ultrasonic probe that carries the above and is in contact with the protruding end of the embedded J-type anchor bolt, and the ultrasonic wave that captures and transmits the received wave from the ultrasonic probe of the J-type anchor bolt. A fixing state determination unit that determines whether the fixing state is good or bad according to whether or not the tip reflected signal of the tip reflected wave reflected at the boundary near the tip of the shaft portion is included in the received signal of the received wave, and the fixing state determination unit. It is characterized by including an output unit that outputs the determination result of the state determination unit.
According to this, if there is a poor fixing point near the surface around the J-type anchor bolt where ultrasonic waves come and go, the tip reflected wave will not be returned from the boundary near the tip of the shaft of the J-type anchor bolt. If the tip reflected signal is included in the received signal, the fixed state of the J-type anchor bolt is good. If the tip reflected signal is not included in the received signal, the fixed state of the J-type anchor bolt is poor. You can judge. That is, it is possible to easily and accurately determine whether or not the J-type anchor bolts embedded in the concrete structure are in a fixed state, regardless of whether or not the reinforcing bars are arranged, depending on the presence or absence of the tip reflection signal.

The fixing state determination device for J-type anchor bolts of the present invention stores the propagation speed of ultrasonic waves in the J-type anchor bolts in a storage unit, and the fixing state determination unit stores the tip reflected wave from the start of transmission of the ultrasonic waves. Recognizing the elapsed time until the reception of the above, and acquiring the distance between the vicinity of the tip of the shaft portion of the J-type anchor bolt and the protruding end of the J-type anchor bolt from the elapsed time and the propagation speed of the ultrasonic wave. It is a feature.
According to this, using the detection of the tip reflected wave, information on the distance between the vicinity of the tip of the shaft of the existing J-type anchor bolt in the concrete structure and the protruding end, and by extension, the fixing length of the existing J-type anchor bolt. Information can be obtained incidentally. Further, detailed information on the fixed state of the J-type anchor bolt can be obtained, and the quality of the fixed state can be determined more accurately.

The fixing state determination method for J-type anchor bolts of the present invention is a fixing state determination method for determining whether the fixing state of J-type anchor bolts embedded in a concrete structure is good or bad, and is a method for determining the fixing state of ultrasonic waves and receiving waves. The ultrasonic probe that bears the above contact with the protruding end of the embedded J-shaped anchor bolt, and the ultrasonic probe transmits ultrasonic waves, and the ultrasonic probe receives and transmits the received wave. The quality of the fixing state is determined according to whether or not the tip reflected signal of the tip reflected wave reflected by the ultrasonic wave at the boundary near the tip of the shaft portion of the J-shaped anchor bolt is included in the received signal of the received wave. It is characterized by doing.
According to this, if there is a poor fixing point near the surface around the J-type anchor bolt where ultrasonic waves come and go, the tip reflected wave will not be returned from the boundary near the tip of the shaft of the J-type anchor bolt. If the tip reflected signal is included in the received signal, the fixed state of the J-type anchor bolt is good. If the tip reflected signal is not included in the received signal, the fixed state of the J-type anchor bolt is poor. You can judge. That is, it is possible to easily and accurately determine whether or not the J-type anchor bolts embedded in the concrete structure are in a fixed state, regardless of whether or not the reinforcing bars are arranged, depending on the presence or absence of the tip reflection signal.

In the method for determining the fixing state of the J-type anchor bolt of the present invention, when it is determined that the fixing state is good, the elapsed time from the start of transmission of the ultrasonic wave to the reception of the tip reflected wave and the J-type anchor bolt It is characterized in that the distance between the vicinity of the tip of the shaft portion of the J-type anchor bolt and the protruding end of the J-type anchor bolt is recognized from the propagation velocity of the ultrasonic wave in.
According to this, using the detection of the reflected wave at the tip, information on the distance between the vicinity of the tip of the shaft of the existing J-type anchor bolt in the concrete structure and the protruding end, and by extension, the fixing length of the existing J-type anchor bolt. Information can be obtained incidentally. Further, detailed information on the fixed state of the J-type anchor bolt can be obtained, and the quality of the fixed state can be determined more accurately.

According to the present invention, it is possible to easily and accurately determine whether the J-type anchor bolt embedded in concrete is in a fixed state.

FIG. 3 is a block diagram of a fixing state determination device for J-type anchor bolts according to the present invention. The flowchart of the fixing state determination processing by the fixing state determination device of the J type anchor bolt of embodiment. The perspective explanatory view which shows the example which the J type anchor bolt is embedded in the concrete structure, and the attachment is attached. (A) is a partial cross-sectional explanatory view for explaining the reflection of ultrasonic waves when the fixing state of the J-type anchor bolt in the fixing state determination process of the embodiment is good, and (b) is J in the fixing state determination process of the embodiment. A partial cross-sectional explanatory view illustrating the reflection of ultrasonic waves when the anchor bolt is poorly fixed. A partial cross-sectional explanatory view of a state in which a J-type anchor bolt, which is the object of an experimental example, is embedded in a concrete structure. (A) to (c) are specimen Nos. Based on J-type anchor bolts of Experimental Examples. 1, No. 2. No. Explanatory drawing explaining 3. (A) to (c) are specimen Nos. 1, No. 2. No. The graph which shows the result of the ultrasonic reflection experiment with respect to 3. Partial cross-sectional explanatory view explaining the reflection position of the tip reflected wave assumed from the experimental result.

[Fixed state determination device and fixing state determination method for J-type anchor bolts of the embodiment]
As shown in FIG. 1, the J-type anchor bolt fixing state determination device 1 according to the present invention is composed of an arithmetic control unit 2 such as an MPU and a CPU, and an HDD, a flash memory, an EEPROM, a ROM, a RAM, and the like. A storage unit 3, an input unit 4 such as a mouse, a keyboard, and a touch panel, an output unit 5 such as a display and a printer, and a timer 6, as well as an ultrasonic generator 7 which is a high voltage generator and ultrasonic waves. An ultrasonic probe 9 having a receiver wave capturing unit 8 that captures a received wave and generates a received signal of the received wave is provided, and an ultrasonic probe 7 and a transducer are electrically connected to the ultrasonic wave generating unit 7 and the received wave capturing unit 8. Therefore, the ultrasonic probe 9 is responsible for transmitting ultrasonic waves and receiving received waves. The fixation state determination device 1 is composed of, for example, a dedicated device, or is a general-purpose computer device such as a personal computer or a mobile terminal such as a smartphone, and has an ultrasonic generator 7, a received wave capture unit 8, and an ultrasonic probe. 9 can be provided and configured, and the input unit 4 and the output unit 5 can be integrated as a touch panel capable of input / output.

The storage unit 3 has a program storage unit 31 in which a predetermined control program including a fixing state determination program is stored, and the arithmetic control unit 2 executes a predetermined process according to the predetermined control program to determine the fixing state. In cooperation with, the fixing state determination unit 21 executes a predetermined process. Further, the storage unit 3 has an ultrasonic data storage unit 32 that stores ultrasonic data generated and transmitted by the ultrasonic probe 9 via the ultrasonic wave generation unit 7, and the fixing state determination unit 21. Recognizes the ultrasonic data of the ultrasonic data storage unit 32 in response to the input from the input unit 4, and generates an ultrasonic wave corresponding to the ultrasonic wave with the ultrasonic probe 9 via the ultrasonic wave generation unit 7. It is designed to be sent.

Further, the storage unit 3 uses the determination reference data for determining whether or not the tip reflected signal of the tip reflected wave reflected at the boundary near the tip of the shaft portion of the J-type anchor bolt is included in the received signal of the received wave. It has a storage unit 33. The determination standard data storage unit 33 stores appropriate determination standard data necessary for the determination process executed by the fixing state determination unit 21. For example, when the fixing state determination unit 21 determines the presence or absence of the tip reflection signal by template matching, the determination reference data storage unit 33 stores the reference template and the threshold value of the waveform signal having the tip reflection signal, and the fixation state determination unit 21 Acquires the degree of correlation between the received signal of the received wave and the reference template, and executes a process of determining that there is a tip reflection signal when the acquired degree of correlation is equal to or greater than the threshold value of the determination reference data storage unit 33. Further, for example, the determination reference data storage unit 33 stores the threshold range of the echo height (intensity of the ultrasonic reflected wave) of the target tip reflection signal and the threshold range of the convergence time, and the fixation state determination unit 21 stores the reception wave. It recognizes whether or not the received signal has a received signal within the threshold range of the echo height (intensity of the ultrasonic reflected wave) and within the threshold range of the convergence time, and if there is the received signal, there is a tip reflected signal. The process of determining that may be executed.

Further, the storage unit 3 has a distance acquisition data storage unit 34 for acquiring the distance between the vicinity of the tip of the shaft portion of the J-type anchor bolt embedded in the concrete structure and the protruding end of the J-type anchor bolt. For example, the propagation speed of ultrasonic waves in the J-type anchor bolt is stored in the distance acquisition data storage unit 34, and the fixing state determination unit 21 uses the timer 6 from the start of ultrasonic wave transmission to the reception of the tip reflected wave. The process of recognizing the elapsed time and acquiring the position near the tip of the shaft portion of the J-type anchor bolt and the distance to the protruding end of the J-type anchor bolt is executed from the elapsed time and the propagation speed of the ultrasonic wave. In addition, the storage unit 3 has a predetermined storage area for storing data necessary for executing a predetermined control program of the arithmetic control unit 2.

The output unit 5 has, for example, an operation screen of the fixing state determination processing, a determination result of the fixing state determination processing such as the presence / absence of the tip reflected signal of the tip reflected wave reflected at the boundary near the tip of the shaft portion of the J-type anchor bolt. When there is a tip reflection signal, the position near the tip of the shaft of the J-type anchor bolt and the distance to the protruding end of the J-type anchor bolt are output. The ultrasonic probe 9 having a transducer transmits the ultrasonic waves generated by applying a voltage by the ultrasonic wave generating unit 7, receives the reflected waves of the transmitted ultrasonic waves, and receives the received waves of the reflected waves. It is designed to output to the wave capturing unit 8.

The J-type anchor bolt for which the fixing state determination process is performed by the fixing state determination device 1 can target an appropriate J-type anchor bolt embedded in a concrete structure. For example, the J-type anchor bolt shown in FIG. 3 can be targeted. Anchor bolt 10 can be used. The J-shaped anchor bolt 10 of FIG. 3 is composed of a shaft portion 11 and a curved portion 12 on the tip end side of the shaft portion 11, and a male screw 13 is formed at the rear portion of the shaft portion 11.

In the example of FIG. 3, the J-type anchor bolt 10 is embedded in the concrete structure 100 in which the concrete reinforcing reinforcing bar 101 is arranged inside, and the rear portion of the J-type anchor bolt 10 protruding from the concrete structure 100. The insertion hole of the base plate 201 of the attachment 200 is externally inserted, and the base plate 201 and the attachment 200 are fixedly attached to the concrete structure 100 by tightening the nut 15 to the male screw 13.

Then, when determining the quality of the fixed state of the J-type anchor bolt by the fixing state determining device 1 of the present embodiment, as shown in FIG. 4, for example, the J-type anchor bolt 10 embedded in the concrete structure 100 The ultrasonic probe 9 is brought into contact with the protruding end 14, and this contact state is maintained (see S1 in FIG. 3). In this state, the fixing state determination unit 21 of the fixing state determination device 1 generates and transmits ultrasonic waves by the ultrasonic probe 9 via the ultrasonic wave generation unit 7 in response to the input from the input unit 4. At the same time, the received wave reflected by the ultrasonic probe 9 is received (see S2 in FIG. 3). The ultrasonic wave transmitted here is preferably a vertical P wave (burst wave), but it can also be a surface SH wave (pulse wave), a surface SV wave (transverse wave), or the like. The frequency is preferably about 2 to 10 MHz.

After that, the received wave capturing unit 8 captures the received wave received by the ultrasonic probe 9 to generate a received signal of the received wave (see S3 in FIG. 3), and the fixing state determination unit 21 uses the determination reference data. Using the determination reference data of the storage unit 33, the transmitted ultrasonic wave is reflected at the boundary B near the tip of the shaft portion 11 of the J-shaped anchor bolt 10 to the received signal of the generated received wave. It is determined whether or not a signal is included (see S4 in FIG. 3 and FIG. 4A). When the fixing state determination unit 21 determines that the tip reflection signal is included, it determines that the fixing state of the J-type anchor bolt 10 is good (see S5 in FIG. 3), and if the tip reflection signal is not included. When it is determined, the fixing state of the J-type anchor bolt 10 is determined to be defective, and the determination result that the fixing state is defective is output from the output unit 5 (see S6 and S7 in FIG. 3).

That is, as shown in FIG. 4A, there is no gap between the J-type anchor bolt 10 and the concrete structure 100, or between the filler around the J-type anchor bolt 10 and the J-type anchor bolt. When 10 is in close contact with the surroundings, the tip reflected signal of the tip reflected wave reflected at the boundary B near the tip of the shaft portion 11 of the high-strength J-type anchor bolt 10 becomes the received signal of the received wave. Since it is contained, it can be judged that the fixing state is good. Further, as shown in FIG. 4B, when the J-type anchor bolt 10 is not in close contact with the surroundings and a gap S exists around the J-type anchor bolt 10, the shaft portion of the J-type anchor bolt 10 Since the tip reflected signal of the tip reflected wave reflected at the boundary B near the tip of 11 is not included in the received signal of the received wave, at least in a clear form, it can be determined that the fixing state is poor. The alternate long and short dash line in FIG. 4 shows an ultrasonic wave and its reflected wave.

Next, when it is determined that the fixing state of the J-type anchor bolt 10 is good, the fixing state determination unit 21 uses the propagation speed of the ultrasonic waves in the J-type anchor bolt 10 of the distance acquisition data storage unit 34 to obtain ultrasonic waves. From the elapsed time from the start of transmission to the reception of the tip reflected wave and the propagation speed of ultrasonic waves in the J-type anchor bolt 10, the position near the tip of the shaft portion 11 of the J-type anchor bolt 10 and the protruding end of the J-type anchor bolt. Recognize the distance to (see S8 in FIG. 3). Then, the fixing state determination unit 21 outputs a determination result indicating, for example, that the fixing state is good, the position near the tip of the shaft portion 11 of the J-type anchor bolt 10 and the distance to the protruding end of the J-type anchor bolt. Output from unit 5 (see S9 in FIG. 3).

Then, for the J-type anchor bolt 10 which is determined to have a defective fixing state between the J-type anchor bolt 10 and the concrete structure 100, the concrete around the defective J-type anchor bolt 10 is scraped. Take appropriate repair measures such as injecting non-shrink mortar and replacing the J-type anchor bolt 10 itself if corrosion of the J-type anchor bolt 10 is observed.

According to the present embodiment, if there is a poorly fixed portion near the surface around the J-type anchor bolt 10 through which ultrasonic waves travel, the tip reflected wave is generated from the boundary B near the tip of the shaft portion 11 of the J-type anchor bolt 10. Based on the fact that it does not return, the J-type anchor bolt 10 is in a good fixing state when the tip reflected signal is included in the received signal, and when the tip reflected signal is not included in the received signal, the J-type anchor It can be determined that the fixed state of the bolt is defective. That is, depending on the presence or absence of the tip reflection signal, it is possible to easily and accurately determine the quality of the fixed state of the J-type anchor bolt 10 embedded in the concrete structure 100 regardless of the presence or absence of the reinforcing bars 101 for reinforcing the concrete. ..

Further, by utilizing the detection of the reflected wave at the tip, information on the position near the tip of the shaft portion 11 of the existing J-type anchor bolt 10 in the concrete structure 100 and the distance to the protruding end 14, and eventually the existing J-type anchor bolt 10 Information on the anchorage length of is also available. Further, detailed information on the fixed state of the J-type anchor bolt 10 can be obtained, and the quality of the fixed state can be determined more accurately.

[Experimental example]
Next, an experimental example in which the fixing state determination process based on the present invention is performed on the J-type anchor bolt 10 shown in FIG. 5 will be described. In FIG. 5, the J-shaped anchor bolt 10 is embedded in the concrete structure 100, the base plate 201 is extrapolated to the protruding portion of the shaft portion 11, and the nut 15 is screwed into the male screw 13 and tightened. In the example of FIG. 5, the distance h1: 800 mm between the tip position of the shaft portion 11 of the J-type anchor bolt 10 (the position where the curved portion 12 starts to bend) and the protruding end 14, and the tip of the shaft portion 11 of the J-type anchor bolt 10. Of the position (the position where the curved portion 12 starts to bend) and the embedded length to the surface of the concrete structure 100 h2: 600 mm, the length of the male screw 13 h3: 170 mm, and the protruding portion of the shaft portion 11 of the J-type anchor bolt 10. Distance h4: 30 mm from the surface of the concrete structure 100 to the tip position of the male screw 13, axial length h5: 107 mm of the curved portion 12 from the tip position of the shaft portion 11 of the J-type anchor bolt 10, J-type anchor The length of the tip of the curved portion 12 extending toward the shaft 11 from the tip position of the shaft 11 of the bolt 10 is set to h6: 53 mm.

Then, as shown in FIG. 6, a sound test piece No. The J-type anchor bolt 10 shown in FIG. 5 was prepared as No. 1, and the test body No. 1 was prepared as a test body in which a gap was intentionally formed around the bolt. 2 and test piece No. 3 was prepared. Specimen No. Reference numeral 2 denotes a gap forming tape ST wound in a range of 300 mm from a position corresponding to the surface of the concrete structure 100 of the J-type anchor bolt 10 in FIG. 5 toward the curved portion 12, and the test piece No. Reference numeral 3 denotes a gap forming tape ST wound in a range of 600 mm from a position corresponding to the surface of the concrete structure 100 of the J-type anchor bolt 10 in FIG. 5 toward the curved portion 12. Each of these test specimens No. 1, No. 2. No. 3 is embedded in the test concrete with an embedding length of 600 mm in the same manner as in FIG. 5, the protruding end 14 of the J-type anchor bolt 10 is smoothed, and the ultrasonic probe 9 of the fixing state determination device 1 is brought into contact with the test concrete. , P waves by burst waves were transmitted and received as ultrasonic waves, and an experiment of fixing state determination processing was conducted. In addition, ultrasonic waves were transmitted at three different frequencies of 3.66 MHz, 4.5 MHz, and 5.0 MHz for experiments.

The results of this experiment are shown in FIG. In FIG. 7, the vertical axis is the intensity of ultrasonic waves, and the horizontal axis is the distance from the protruding end 14 (transmission / reception position of ultrasonic waves) of the J-type anchor bolt 10 to the reflection point where the reflected wave is obtained. The distance to the reflection point on the horizontal axis is calculated from the propagation speed of ultrasonic waves of the reinforcing bar, which is the material of the J-type anchor bolt 10, and the elapsed time from the start of transmission of ultrasonic waves to the reception of reflected waves. ..

As shown in FIG. 7 (a), a sound specimen No. In No. 1, the tip reflected signal of the tip reflected wave reflected at the boundary B near the tip of the shaft portion 11 of the J-type anchor bolt 10 was detected at a position 830 mm from the ultrasonic probe 9. On the other hand, as shown in FIGS. 7 (b) and 7 (c), the test body No. 1 wound with the gap forming tape ST was wound. 2 and test piece No. From No. 3, the test piece No. The tip reflected signal of the tip reflected wave like 1 was not detected. Sound test piece No. The reflection position P of 830 mm at which the tip reflection signal of the tip reflected wave in No. 1 is generated is presumed to be a position where the J-type anchor bolt 10 starts to bend slightly (see FIG. 8). Furthermore, as a result of conducting the same test with the base plate, washer, and nut attached at the installation site of the actual J-type anchor bolt as shown in Fig. 3, all of the sound J-type anchor bolts are specified. The tip reflected signal of the tip reflected wave from the depth position of was detected.

[Scope of inclusion of the invention disclosed herein]
The inventions disclosed in the present specification are specified by changing these partial contents to other contents disclosed in the present specification to the extent applicable, in addition to the inventions and embodiments listed as inventions. Alternatively, those specified by adding other contents disclosed in the present specification to these contents, or those specified by deleting these partial contents to the extent that a partial effect can be obtained and making them into a higher concept. Include. The invention disclosed in the present specification also includes the following contents and modifications.

For example, in the above embodiment, the fixing state determination unit 21 determines the axis of the J-type anchor bolt 10 from the elapsed time from the start of transmission of ultrasonic waves to the reception of the tip reflected wave and the propagation speed of the ultrasonic waves in the J-type anchor bolt 10. The configuration is such that the position near the tip of the portion 11 and the distance to the protruding end of the J-type anchor bolt are acquired. However, by inputting the protruding length of the J-type anchor bolt 10 from the concrete structure 100 from the input portion 4, etc. , Stored in a predetermined storage area of the storage unit 3, and after the fixing state determination unit 21 acquires the position near the tip of the shaft portion 11 of the J-type anchor bolt 10 and the distance to the protruding end of the J-type anchor bolt, this The protrusion length of the J-type anchor bolt 10 may be subtracted from the distance to obtain the fixing length, and the J-type anchor bolt 10 may be output from the output unit 5.

Further, in the fixing state determination device and the fixing state determination method in the present invention, the J-type anchor is not subjected to the process of acquiring the distance between the vicinity of the tip of the shaft portion of the J-type anchor bolt and the protruding end of the J-type anchor bolt. It includes only the process of determining the quality of the fixed state depending on whether or not the tip reflected signal of the tip reflected wave reflected at the boundary near the tip of the shaft of the bolt is included in the received signal of the received wave. .. Further, the fixing state determination method in the present invention includes a method in which an operator or the like artificially determines the presence or absence of a tip reflected signal of a tip reflected wave.

INDUSTRIAL APPLICABILITY The present invention can be used to determine the fixed state of J-type anchor bolts embedded in a concrete structure.

1 ... J-type anchor bolt fixing state determination device 2 ... Calculation control unit 21 ... Fixing state determination unit 3 ... Storage unit 31 ... Program storage unit 32 ... Ultrasonic data storage unit 33 ... Judgment reference data storage unit 34 ... For distance acquisition Data storage unit 4 ... Input unit 5 ... Output unit 6 ... Timer 7 ... Ultrasonic generation unit 8 ... Received wave capture unit 9 ... Ultrasonic probe 10 ... J-type anchor bolt 11 ... Shaft part 12 ... Curved part 13 ... Male screw 14 ... Protruding end 15 ... Nut 100 ... Concrete structure 101 ... Reinforcing bar for concrete reinforcement 200 ... Attachment 201 ... Base plate B ... Boundary near the tip of the shaft of J-type anchor bolt S ... Void ST ... Gap forming tape P ... Reflection position

Claims (4)

It is a fixing state judgment device that judges the quality of the fixing state of J-type anchor bolts embedded in a concrete structure.
An ultrasonic probe that is responsible for transmitting ultrasonic waves and receiving received waves and is in contact with the protruding end of the embedded J-type anchor bolt.
The received wave is captured from the ultrasonic probe, and the transmitted ultrasonic wave is reflected at the boundary near the tip of the shaft portion of the J-shaped anchor bolt. The tip reflected signal of the tip reflected wave is the received signal of the received wave. A fixing state determination unit that determines the quality of the fixing state according to whether or not it is included in
A J-type anchor bolt fixing state determination device including an output unit that outputs a determination result of the fixing state determination unit. The propagation velocity of ultrasonic waves in the J-type anchor bolt is stored in the storage unit, and
The fixing state determination unit recognizes the elapsed time from the start of transmission of the ultrasonic wave to the reception of the tip reflected wave, and from the elapsed time and the propagation speed of the ultrasonic wave, the shaft portion of the J-type anchor bolt The fixing state determination device for J-type anchor bolts according to claim 1, wherein the distance between the vicinity of the tip and the protruding end of the J-type anchor bolt is acquired. It is a fixing state determination method for determining the quality of the fixing state of J-type anchor bolts embedded in a concrete structure.
The ultrasonic probe responsible for transmitting ultrasonic waves and receiving received waves abuts on the protruding end of the embedded J-type anchor bolt.
An ultrasonic wave is transmitted from the ultrasonic probe and a received wave is received by the ultrasonic probe.
Whether the fixed state is good or bad depending on whether or not the tip reflected signal of the tip reflected wave of the transmitted ultrasonic wave reflected at the boundary near the tip of the shaft portion of the J-type anchor bolt is included in the received signal of the received wave. A method for determining the fixing state of J-type anchor bolts, which comprises determining. When it is determined that the fixing state is good, the axis of the J-type anchor bolt is determined from the elapsed time from the start of transmission of the ultrasonic wave to the reception of the tip reflected wave and the propagation speed of the ultrasonic wave in the J-type anchor bolt. The method for determining a fixing state of a J-type anchor bolt according to claim 3, wherein the distance between the vicinity of the tip of the portion and the protruding end of the J-type anchor bolt is recognized.

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