JP2003185542A - Concrete sample for nondestructive inspection, defective body used for the same, and manufacturing method for the concrete sample for nondestructive inspection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concrete sample for nondestructive inspection that can easily compare and evaluate each kinds of nondestructive inspection method by assuming the conditions of actual structures, to provide a defective body used for the concrete sample, and to provide a manufacturing method for the concrete sample for nondestructive inspection. <P>SOLUTION: A concrete sample 11 is formed in a long rectangular plate shape using high-fluid concrete. An upper reinforcing bar 13 and a lower reinforcing bar 14 are arranged up and down inside the concrete sample 11. A plurality of disk-like or columnar defective bodies 15 is fixed to a specific position in the upper and lower reinforcing bars 13 and 14. The defective bodies 15 are composed of defective and reinforcing sections, and the defective sections are formed by foamed polystylene as a foamed body. Then, the defective bodies 15 are buried into the concrete sample 11, and the positions are determined three-dimensionally from the outer-periphery surface of the concrete sample 11. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete specimen for nondestructive inspection used for nondestructive inspection such as a hammering method, an impact elastic wave method, and an ultrasonic method, and a defective body and concrete for nondestructive inspection used therein. The present invention relates to a method for manufacturing a specimen.

[0002]

2. Description of the Related Art Conventionally, in the maintenance of concrete structures such as bridges and buildings, the diagnosis of the concrete structures has been performed mainly by visual inspection. Based on the result of this diagnosis, the service life of the concrete structure is maintained by properly repairing the deteriorated parts.

In recent years, nondestructive inspection methods such as a tapping method, a shock elastic wave method, an ultrasonic method, a thermography method, and an acoustic elastic wave method have been known. Moreover, diagnosis of concrete structures is also performed by these nondestructive inspection methods, and by combining nondestructive inspection and visual inspection, the objectivity of information on deterioration and deformation of the structure can be improved and Attempts have been made to obtain information on. In addition, since there is no universal non-destructive inspection method for diagnosing concrete structures, attempts have been made to combine a plurality of non-destructive inspection methods.

On the other hand, the performance evaluation of accuracy, application range, inspection efficiency, etc. of various non-destructive inspection methods on an actual concrete structure has been conducted by sampling the actual concrete structure. Concretely, there are cutting work of concrete structure, measurement work by non-destructive inspection device, dismantling work of concrete structure, measurement work of shape and size of defective portion, data analysis work and the like.

[0005]

However, in the performance evaluation of the above-mentioned conventional nondestructive inspection method, an actual concrete structure once used is dismantled and cannot be remeasured. Therefore, most of the evaluation results of non-destructive inspection methods for actual concrete structures are individual data. That is, there is a problem that it is difficult to compare and evaluate various nondestructive inspection methods under the assumption of actual structure conditions.

The present invention has been made by paying attention to the problems existing in the above prior art. The purpose is to provide concrete specimens for nondestructive inspection, which can easily compare and evaluate various nondestructive inspection methods assuming actual structure conditions, and concretes for defective and nondestructive inspections used in them. It is to provide a method for manufacturing a specimen.

[0007]

In order to achieve the above object, a concrete specimen for nondestructive inspection according to the invention of claim 1 is a defect formed on the assumption of a defect occurring inside a concrete structure. The body and the reinforcing bars are embedded inside the concrete, and the position of the defective body is three-dimensionally determined from the outer peripheral surface of the concrete.

The defective body used in the concrete specimen for nondestructive inspection according to the second aspect is a defective body embedded in the concrete specimen for nondestructive inspection according to the first aspect, which is a foam. It is composed of a defect portion consisting of.

The defective body used in the concrete specimen for nondestructive inspection according to the third aspect of the invention is the defective body according to the second aspect of the invention, in which the defective portion is joined to a reinforcing portion formed of mortar. It is a thing.

The defect body used in the concrete specimen for nondestructive inspection of the invention described in claim 4 is formed in a disk shape or a column shape in the invention described in claim 2 or claim 3. Is.

According to a fifth aspect of the present invention, there is provided a method for producing a concrete specimen for nondestructive inspection, in which a defective body formed assuming a defect occurring inside a concrete structure and a reinforcing bar are embedded inside the concrete. A method for manufacturing a non-destructive inspection concrete specimen in which the position of the defective body is three-dimensionally determined from the outer peripheral surface of the concrete, wherein the defective body and reinforcing bars are arranged in a concrete form, and the defective body is Is fixed to the concrete formwork or rebar,
Concrete is placed in a concrete form.

The method for producing a concrete specimen for nondestructive inspection according to a sixth aspect of the present invention is the defective body used in the concrete specimen for nondestructive inspection according to the fourth aspect of the invention. Place the peripheral surface of the up and down,
Concrete is poured from above.

A method for producing a concrete specimen for nondestructive inspection according to a seventh aspect of the present invention is the method according to the fifth or sixth aspect, in which high-fluidity concrete having self-filling property is poured, It is molded without vibration.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. The front, rear, left and right in the following description are based on the front, rear, left and right in FIG.

As shown in FIGS. 1 and 2, the concrete specimen 11 is a model of an actual bridge deck, and is made of concrete in the shape of a rectangular plate. Inside the concrete specimen 11, an upper rebar 13 and a lower rebar 1 which are formed into a rectangular frame shape by welding the rebar 12 are formed.
4 are arranged one above the other. A plurality of disk-shaped defective bodies 15 are fixed at predetermined positions of the upper reinforcing bar 13 and the lower reinforcing bar 14.

The defect body 15 is formed on the assumption that the defect occurs inside the concrete, and the size thereof is 50 to 5 in diameter.
It is set in the range of 00 mm. This range is suitable for evaluating various nondestructive inspection methods. If the diameter of the defective body 15 is less than 50 mm, detection by various nondestructive inspection methods is often difficult. On the other hand, 500
If it exceeds mm, there will be no difference in the measurement data of various nondestructive inspection methods, making comparative evaluation difficult.

The dimension of the concrete specimen 11 is 2.
The size is 0 m, the width is 4.0 m, and the thickness is 0.2 m, which makes it easy to transport. The concrete specimen 11 is made of high-fluidity concrete. Generally, high-fluidity concrete has improved fluidity without impairing material separation resistance. The high-fluidity concrete referred to in the present specification means concrete that can be self-filled without using a vibration exciter when it is placed in a mold. High-fluidity concrete is blended with high-performance water reducing agents such as naphthalene, melamine and polycarboxylic acid, and further contains a large amount of powder materials such as blast furnace slag fine powder, fly ash and silica fume, and thickening agents such as cellulose Those containing an agent are known.

As shown in FIG. 1, the upper rebars 13 are provided with lattice-shaped rebars 12 in the front approximately half and a space 16 is formed in the rear approximately half. On the other hand, the lower reinforcing bar 14 has the reinforcing bars 12 arranged in a lattice pattern on the entire surface. Therefore, approximately half of the front side of the concrete test piece 11 is a portion in which the upper rebar 13 and the lower rebar 14 are embedded, and approximately half of the rear side is a portion in which only the lower rebar 14 is embedded.

The defect bodies 17, 18, 19, 20, 21, 22 and the defect body 23 are fixed to the upper left reinforcing member 13 approximately one quarter on the left front side. The diameters of these defective bodies 17 to 23 are 50, 100, 500, 150, 300, in order.
It is formed to 200 and 300 mm. Lower rebar 14
13 defect bodies 24, 25, 26, 27, 28, 29, 30, 31, 3 are provided on the upper surface except the left front side approximately 1/4.
2, 33, 34, 35 and the defective body 36 are fixed. The diameters of these defective bodies 24 to 36 are 300,
200, 200, 300, 300, 150, 500, 5
It is formed to 00, 100, 50, 500, 300 and 200 mm.

As shown in FIG. 2, for example, the center of the defective body 19 is set at a distance of L1 from the left side surface of the concrete specimen 11 and L2 from the front side surface thereof. Further, as shown in FIG. 3, the upper surface of the defective body 19 is set at a distance L3 from the upper surface of the concrete specimen 11. As described above, the position of each defective body 15 from the outer peripheral surface of the concrete specimen 11 is three-dimensionally determined by the distances L1, L2, and L3.

Defects 25, 27, 30 and Defect 34
The lower reinforcing bars 14 are arranged at the positions where the to 36 are arranged, but the upper reinforcing bars 13 are not arranged. The defective bodies 17 to 23 are arranged on the upper reinforcing bar 13, and the reinforcing bar 12 is not arranged above. On the other hand, at the location where the defective bodies 24 to 33 are arranged, the upper rebar 13
And the lower rebar 14 is arranged. That is, there are a defective body in which the reinforcing bars 12 are arranged and a defective body in which the reinforcing bars 12 are not arranged above.

The defective body 15 will be described in detail. As for the defective bodies other than the defective bodies 23 and 24, as shown in FIGS.
The foamed body is composed of a disc-shaped defect portion 37 made of expanded polystyrene having a thickness of 5 mm and a disc-shaped reinforcing portion 38 made of mortar. The styrene foam forming the defect portion 37 has an acoustic impedance (acoustic property of a substance defined as a product of density and sound velocity) close to that of air (cavity). Therefore, it is possible to easily simulate a cavity as a defect generated inside the concrete structure. An adhesive layer (not shown) is provided between the deficient portion 37 and the reinforcing portion 38, and they are joined so that their surfaces are aligned with each other. Specific examples of the adhesive forming the adhesive layer include a polyvinyl acetate solvent type adhesive (Konishi KE60,
Konishi Co., Ltd.) and the like.

Defect body 23 arranged on the upper rebar 13
Is a mockup of Junka
The thickness is about 15 mm. The defective body 24 arranged on the lower rebar 14 is a simulated cold joint, and grease is applied to the slant cut portion of a slant cut cylinder having a thickness of 10 to 15 mm. These defective bodies 23 and 24 are made of concrete (pretascon,
Formed by Denki Kagaku Kogyo Co., Ltd.

The reinforcing portion 38 forming the defective body 15 other than the defective bodies 23 and 24 has a plurality of 0.9 mm stainless steel wires 38a extending outwardly on the outer peripheral surface thereof. The defective body 15 can be fixed to the upper reinforcing bar 13 or the lower reinforcing bar 14 by binding these wires 38a to the reinforcing bar 12 constituting the upper reinforcing bar 13 or the lower reinforcing bar 14. Furthermore, inside the reinforcing portion 38, the diameter is 4 mm.
A disk-shaped wire net 38c reinforced by the reinforcing bars 38b is embedded as a reinforcing material. Further, by changing the thickness of the reinforcing portion 38, the concrete specimen 11 of the defective body 15
The distance L3 from the top surface of the can be adjusted. As shown in FIG. 6 and FIG. 7, a pair of long quadrangular prism bases 38d are provided on the lower surface of the reinforcing portion 38 of the defective bodies 34 to 36, and the distance L3 can be adjusted also by these bases 38d. You can The thickness of the reinforcing portion 38 of the defective bodies 17 to 22 located in the left half of the concrete specimen 11 is 1
0 mm, the height of the reinforcing portion 38 provided with the base portion 38d of the defective bodies 34 to 36 is set to 96 mm, and the distance L3 between the defective bodies 17 to 22 and the defective bodies 34 to 36 is 30 mm.
Is set to. On the other hand, the thickness of the reinforcing portion 38 of the defective bodies 23 to 32 located in the substantially right half of the concrete sample 11 is set to 28 mm, and the distance L3 is set to 100 mm.

Now, the defective body 15 other than the defective bodies 23 and 24
The method for producing is described below. First, thickness 5
The mm styrofoam plate is cut into a predetermined size to form the defect portion 37. Next, as shown in FIG. 8, the center of the wooden board is cut into a predetermined size to form a form 39. The base ends of a plurality of wires 38a are bound to a wire net 38c reinforced by reinforcing bars 38b, and the tips of the wires 38a are directed outwards.
After placing c in the mold 39, mortar is placed in the mold 39. The reinforcing portion 38 is formed by curing and curing the mortar and removing the mold 39. Then, the defective portion 37 and the reinforcing portion 38 are adhered to each other by an adhesive agent so that the defective body 2
Defects 15 other than 3 and 24 are formed.

Defective body 23 simulating a junker
Is the above-mentioned form 3 of concrete in which aggregate and water are separated.
It is formed by being cast in the inside 9. For the defective body 24 simulating a cold joint, wires are arranged in a cylindrical mold frame (not shown). Then, concrete is poured and cured to form a cylindrical concrete molded product. After the upper surface of this concrete molded product is obliquely cut, grease is applied to the obliquely cut portion to form the defective body 24. According to this, close contact between the obliquely cut portion and the concrete forming the concrete test piece 11 is hindered, and a cold joint can be easily formed.

Next, a method for manufacturing the concrete specimen 11 will be described below. First, the reinforcing bars 12 are arranged as shown in FIG. 1 to form the upper reinforcing bars 13 and the lower reinforcing bars 14. Then, each defective body 15 is fixed at a predetermined position of the upper reinforcing bar 13 and the lower reinforcing bar 14. At this time, as shown in FIGS. 4 to 7, the reinforcing portion 38 is provided with the wire 38a. Therefore, by binding the wire 38a to the reinforcing bar 12, the defective body 15 can be easily fixed at a predetermined position of the upper reinforcing bar 13 and the lower reinforcing bar 14.

Next, the upper reinforcing bar 13 and the lower reinforcing bar 14 are connected and fixed by a reinforcing reinforcing bar (not shown) and vertically arranged in the concrete form 40 shown in FIG. Then, as shown by the arrow in FIG. 9, high-fluidity concrete as concrete is made to flow down from above, and it is placed without vibration and is cured and cured.
At this time, the defective body 15 has the upper rebar 13 and the lower rebar 14
It is fixed by a wire 38a. Therefore, concrete can be poured without moving the position of the defective body 15. Further, the upper rebar 13 and the lower rebar 1
4 are arranged vertically, and the peripheral surface of the defective body 15 is arranged vertically. Therefore, when the concrete is flowed down from above and is poured, the bubbles trapped under the defective body 15 quickly escape upward along both side surfaces and the peripheral surface of the curved defective body 15. When the upper rebars 13 and the lower rebars 14 are arranged laterally and concrete is flowed down from above, bubbles are likely to stay on the lower surface of the defective body 15.

In addition, the defective body 15 other than the defective bodies 23 and 24
Since the deficient portion 37 constituting the above is joined to the reinforcing portion 38, even if the deficient portion 37 is impacted by concrete, the shape can be maintained by being supported by the reinforcing portion 38. Since the concrete specimen 11 is formed by pouring high-fluidity concrete and pouring it without vibration, the concrete can be sufficiently filled around the defect body 15 and the extra stress caused by the vibration is generated. It is not given to the defective body 15.

The effects exhibited by this embodiment will be described below. In the concrete test piece 11 of this embodiment, the defective bodies 15 are formed on the assumption of defects that occur inside the concrete, and the positions of these defective bodies 15 are L1, L2 from the outer peripheral surface of the concrete test piece 11. And L3
Is determined three-dimensionally by. With this configuration, it is possible to easily compare and evaluate various nondestructive inspection methods assuming actual structure conditions.

The defect bodies 15 other than the defect bodies 23 and 24 of this embodiment are made of styrofoam. According to this structure, the styrene foam has an acoustic impedance (acoustic property of a substance defined as a product of density and speed of sound) close to that of air (cavity). Therefore, it is possible to easily simulate a cavity as a defect generated inside the concrete structure. It is possible to easily simulate a cavity as a defect that occurs inside a concrete structure. Also, since Styrofoam is excellent in workability,
The defective body can be easily manufactured.

In the defective bodies 15 other than the defective bodies 23 and 24 of this embodiment, the defective portion 37 is joined to the reinforcing portion 38 formed of mortar. According to this configuration, the defective portion 37 due to the impact when pouring concrete
Can be prevented from being damaged.

The defect body 15 of this embodiment is formed in a disc shape or a column shape. According to this configuration, since the defective body 15 does not have a corner portion having a large variation in accuracy by various nondestructive inspections, various nondestructive methods can be compared and evaluated more easily.

In the method for manufacturing the concrete specimen 11 for nondestructive inspection of this embodiment, the defective body 15 is fixed to the reinforcing bar 12 and concrete is poured. Therefore, the position of the defective body 15 can be set easily and surely.

In the method for manufacturing the concrete specimen 11 for nondestructive inspection of this embodiment, the peripheral surface of the defective body 15 is arranged vertically and the concrete is poured from above. Therefore, the bubbles trapped under the defective body 15 can be quickly removed upward while the concrete is being poured, so that the surroundings of the defective body 15 can be sufficiently filled with concrete.

In the method for manufacturing the concrete specimen 11 for nondestructive inspection of this embodiment, high-fluidity concrete is poured and molded without vibration. Therefore, it is possible to sufficiently fill the periphery of the defective body 15 with concrete and prevent the defective body 15 from being displaced or damaged due to vibration.

The concrete specimen 1 of this embodiment
In No. 1, there are a defective body 15 in which the reinforcing bars 12 are arranged and a defective body 15 in which the reinforcing bars 12 are not arranged above. Therefore, when comparatively evaluating various nondestructive inspection methods under the assumption of actual structure conditions, it is possible to evaluate the influence of the reinforcing bar 12 located above the defective body 15.

In the defective bodies 15 other than the defective bodies 23 and 24 of this embodiment, the defective portion 37 is joined to the reinforcing portion 38. Further, the reinforcing portion 38 of the defective bodies 34 to 36
The base 38d is provided in the. According to this configuration,
The distance L3 of the defective body 15 from the upper surface of the concrete specimen 11 can be easily adjusted.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to FIG. As shown in FIG. 10, the upper rebars 13 have the reinforcing bars 12 arranged in a grid pattern in substantially the front half thereof, and the space 16 is formed in the substantially rear half thereof. The lower rebar 14 has a space 16 formed in approximately one-fourth of the left rear side, and the rebars 12 are arranged in a lattice pattern in other portions. The left rear side approximately one-quarter of the concrete specimen 11 is a non-reinforced portion in which the reinforcing bar 12 is not embedded. The right side of this unreinforced portion is a portion in which only the lower reinforcing bar 14 is embedded, and the front approximately half is a portion in which the upper reinforcing bar 13 and the lower reinforcing bar 14 are embedded.

On almost the right half of the lower surface of the lower reinforcing bar 14, the defective bodies 41, 42, 43, 44, 45, 4 are formed as the defective bodies 15.
6, 47 and 48 are fixed. These defects 4
The diameters of 1 to 48 are 200, 200, 300, 30 in order.
It is formed at 0, 150, 500, 500, 100 and 50 mm. Then, the position of each defective body 15 from the outer peripheral surface of the concrete specimen 11 is three-dimensionally determined by the distances L1, L2, and L3 as in the first embodiment. The distance L3 between the upper surface of the concrete specimen 11 of the present embodiment and each defective body 15 is set to 170 mm.

The left half of the concrete specimen 11 is a healthy part in which the defective body 15 is not buried. The upper reinforcing bars 13 and the lower reinforcing bars 14 are embedded in approximately the front half of the sound portion, and the reinforcing bars 12 are not embedded in the rear approximately half.

Therefore, in the concrete specimen 11 in the second embodiment, by comparing and analyzing the level difference between the measured value of the sound portion and the measured value of the defective portion in which the defective body 15 is buried, various non-destructive tests are performed. The detection limit of the test method can be easily evaluated. In addition, it is possible to easily evaluate the influence of the presence or absence of the reinforcing bar 12 in the measured value of the healthy portion.

[0043]

EXAMPLES Next, the embodiment will be described more specifically by way of examples. Various non-destructive inspection methods were evaluated using the concrete specimen 11 described above. The method used is
Among the elastic wave methods, there are a tapping method, a shock elastic wave method, and an ultrasonic method. [Striking method and impact elastic wave method] The hitting was input by dropping a steel ball. The steel balls used have diameters of 20 mm and 30 mm.
There are two types. A steel ball with a diameter of 20 mm was used to compare the frequency distribution of the received waveform. Also, the diameter is 30 mm
The steel ball of was used for comparison of the maximum amplitude value of the received waveform. These steel balls were dropped to the center of the portion where the defective body 15 was buried. In each case, the falling height of the steel balls was 10 cm. A microphone (manufactured by RION, condenser microphone) was used to measure the impact sound. An accelerometer (3110D manufactured by DYTRAN) was used to measure the surface vibration. Accelerometer is 5c horizontally from steel ball drop position
m and the microphone were installed 10 cm directly above the accelerometer. In signal measurement, the received waveform is passed through an amplifier to a high-speed AD converter (NR35, manufactured by Keyence Corporation).
It was recorded on a personal computer through 0).

Then, the maximum amplitude value of the impact sound was measured, and the ratio of the values of the sound portion and the portion in which the defective body was embedded was taken as the maximum amplitude value ratio. When the maximum amplitude value ratio is larger than 2, the defective body 15 can be clearly detected (◯), and when it is less than 2, the detection is difficult (×). The evaluation results are shown in Table 1.

[0045]

[Table 1] From the results in Table 1, the maximum amplitude value of the tapping method is 3c in depth.
It can be seen that it is possible to detect defects within m and having a diameter of 15 cm or more.

Next, evaluation was made based on the fact that the measured frequency distribution has a single-peaked peak (∘), the distribution shape is the same as that of a healthy portion (x), and the peak is unknown (-). The evaluation results of the tapping method are shown in Table 2, and the evaluation results of the impact elastic wave method are shown in Table 3.

[0047]

[Table 2]

[0048]

[Table 3] From the results of Tables 2 and 3, it is understood that defects having a depth of 3 cm or less and a diameter of 10 cm or more can be detected by the frequency distribution of the tapping method and the impact elastic wave method. Further, it can be seen that defects with a depth of 10 cm or less and a diameter of 15 cm or more can also be detected. [Ultrasound Method] One of the ultrasonic methods was evaluated by the probe reflection method. The reflected wave was measured at the center of the portion of the concrete specimen 11 in which the defective body 15 was buried. For this measurement, a low-frequency ultrasonic measuring device (manufactured by Mitsubishi Electric Corporation, UI-
22) was used.

Table 4 shows the results of evaluation with respect to the reflection echoes caused by the defective body 15 and the reinforcing bars 12 (◯), not confirmed (x) and unknown reflection echoes (-).

[0050]

[Table 4] From the results in Table 4, it can be seen that all the defects can be detected within the range of this experiment by the reflection echo of the ultrasonic method.

The above embodiment may be modified and embodied as follows. In the above-mentioned embodiment, the defective body 15 is fixed to the reinforcing bar 12, but the defective body 15 may be fixed to the concrete form 40.

In the above-mentioned embodiment, the polystyrene foam formed of polystyrene resin is used as the defective portion made of foam, but foam formed of other synthetic resins such as urethane resin and polyethylene resin or various synthetic rubbers. It can be the body. It may also be a foam formed from a natural material such as pulp, cellulose, natural rubber or the like.

In the above-described embodiment, the reinforcing portion 38 is joined to one surface of the defective portion 37, but the reinforcing portion 38 may be joined to both surfaces of the defective portion 37 to form the defective body 15. With this configuration, it is possible to further prevent damage to the defective portion 37 due to an impact when pouring concrete.

In the above-mentioned embodiment, the concrete specimen 11 is formed in a rectangular plate shape, but it may be formed in a rectangular parallelepiped or a cube. Next, technical ideas that can be understood from the above-described embodiment will be described below.

(1) The defective body used in the concrete specimen for nondestructive inspection according to claim 2, wherein the defective portion is made of expanded polystyrene. According to this structure, since it can be easily processed, the defective body can be easily manufactured. Further, the styrene foam has an acoustic impedance (acoustic property of a substance defined as a product of density and sound velocity) close to that of air (cavity). Therefore, it is possible to easily simulate a cavity as a defect generated inside the concrete structure.

(2) A defective body used for a concrete specimen for nondestructive inspection according to claim 3, wherein a wire for fixing to a reinforcing bar or a mold is attached to the reinforcing portion. According to this configuration, the defective body can be easily fixed at a predetermined position of the reinforcing bar or the mold.

(3) The non-destructive inspection concrete according to claim 1, wherein approximately half of the concrete specimen is a defective portion in which a defective body is embedded, and the other portion is a sound portion in which a defective body is not embedded. Specimen. According to this configuration, by comparing and analyzing the level difference between the measured value of the sound portion and the measured value of the defective portion, it is possible to easily evaluate the detection limit of various nondestructive inspection devices.

[0058]

Since the present invention is constructed as described above, it has the following effects. According to the concrete specimen for nondestructive inspection described in claim 1, various nondestructive inspection methods can be easily compared and evaluated on the assumption of actual structure conditions.

According to the defective body used in the concrete specimen for nondestructive inspection according to the second aspect, it is possible to easily simulate a cavity as a defect generated inside the concrete structure.

According to the defect body used in the concrete specimen for nondestructive inspection described in claim 3, in addition to the effect of the invention described in claim 2, in addition to the effect of the invention, the defect part caused by the impact at the time of placing concrete It is possible to prevent damage.

According to the defective body used for the non-destructive inspection concrete specimen according to claim 4, in addition to the effect of the invention according to claim 2 or 3, various non-destructive inspection methods can be more easily performed. Can be compared and evaluated.

According to the method for producing a concrete specimen for nondestructive inspection of claim 5, the position of the defective body can be set easily and surely. According to the method for producing a concrete specimen for nondestructive inspection described in claim 6, in addition to the effect of the invention described in claim 5, concrete can be sufficiently filled around the defective body.

According to the method for producing a concrete specimen for nondestructive inspection described in claim 7, in addition to the effect of the invention described in claim 5 or 6, concrete is sufficiently filled around the defective body. It is possible to prevent the displacement and damage of the defective body due to vibration.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a concrete test piece according to a first embodiment.

FIG. 2 is a plan view showing a concrete test piece.

FIG. 3 is a partially enlarged sectional view showing a concrete specimen.

FIG. 4 is an exploded perspective view showing a defective body.

FIG. 5 is a perspective view showing a defective body.

FIG. 6 is an exploded perspective view showing a defective body provided with a base portion.

FIG. 7 is a perspective view showing a defective body provided with a base portion.

FIG. 8 is a perspective view showing a mold, a reinforcing material, and a wire for manufacturing the reinforcing portion of the defective body.

FIG. 9 is a schematic diagram showing a method for manufacturing a concrete specimen.

FIG. 10 is an exploded perspective view showing a concrete test piece according to the second embodiment.

[Explanation of symbols]

11 ... Concrete specimen, 12 ... Reinforcing bar, 15 ... Missing body, 37 ... Missing part, 38 ... Reinforcing part, 40 ... Concrete formwork.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukio Endo             Showa Con, 1-1, Koran, Gifu City, Gifu Prefecture             Cleat Industry Co., Ltd. (72) Inventor Toshiro Kamata             No. 1-8 Norichu, Gifu City, Gifu Prefecture (72) Inventor Yoshiaki Kobayashi             2 49, Yurakucho, Kasamatsu-cho, Hashima-gun, Gifu Prefecture F term (reference) 2G047 AA10 BA03 BA04 BB01 BC09                       CA01 CA03 EA11 GG16 GJ22                 2G052 AA16 AA39 AD53 FD12 GA26                       HC21

Claims (7)

[Claims] 1. A defective body formed assuming a defect occurring inside a concrete structure, and a reinforcing bar embedded in the concrete, and the position of the defective body is three-dimensionally determined from the outer peripheral surface of the concrete. A concrete specimen for nondestructive inspection characterized by the fact that 2. A concrete specimen for nondestructive inspection, wherein the concrete specimen for nondestructive inspection according to claim 1 is embedded in the concrete specimen for nondestructive inspection, and comprises a defective portion made of foam. A defective body used for the sample. 3. The defective body used for the concrete specimen for nondestructive inspection according to claim 2, wherein the defective portion is joined to a reinforcing portion formed of mortar. 4. A defective body used in the concrete specimen for nondestructive inspection according to claim 2 or 3, which is formed in a disc shape or a column shape. 5. A defective body formed assuming a defect occurring inside a concrete structure and a reinforcing bar embedded in the concrete, and the position of the defective body is three-dimensionally determined from the outer peripheral surface of the concrete. A method for manufacturing a concrete specimen for non-destructive inspection, wherein the defective body and reinforcing bars are arranged in a concrete formwork,
A method for producing a concrete specimen for nondestructive inspection, comprising placing concrete in a concrete form with the defective body being fixed to the concrete form or a reinforcing bar. 6. The non-destructive inspection according to claim 5, wherein the peripheral surfaces of the defect bodies used in the concrete test specimen for non-destructive inspection according to claim 4 are arranged so as to face up and down, and concrete is poured from above. For manufacturing concrete specimens for concrete. 7. The method for producing a concrete specimen for nondestructive inspection according to claim 5 or 6, wherein high-fluidity concrete having self-filling property is poured and molded without vibration.