JP3199108B2 - Concrete member and its crack detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a concrete member and a method for detecting cracks in a concrete member.

[0002]

2. Description of the Related Art Generally, when investigating the presence or absence of cracks generated in concrete or the location of the cracks, it is common to visually approach the surface of the building or to observe it with a loupe.

[0003]

However, when the crack width is as small as 0.1 mm or less, for example, it is difficult to find it unless approaching to a close distance and observing it with a loupe or the like. There is a risk of overlooking the occurrence of

[0004] Further, in the seismic diagnosis for evaluating the soundness of concrete members by investigating the degree of damage caused by the earthquake, furniture and fixtures scattered by the earthquake are obstructive and cannot approach the target concrete member. However, not only small cracks but also large cracks could not be found to a certain extent, causing a problem that the judgment of the degree of damage to concrete was delayed.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a concrete member capable of detecting cracks in concrete at an early stage even at a short distance and a method for detecting the cracks. And

[0006]

In order to achieve the above object, a concrete member according to the present invention is formed of a brittle material such as glass as described in claim 1, and a detection liquid such as colored ink is sealed in the hollow interior. The detected object is buried in the concrete body, and when the strain is applied to the extent that cracks occur in the concrete, the detection liquid flows out as the concrete is cracked or damaged similarly to the concrete. The compressed gas is sealed in the detection body.

In the concrete member of the present invention, a hollow detection tube made of a brittle material such as glass is embedded in a concrete body and an injection port communicating with the detection tube. Is provided on the surface of the skeleton, and the detection tube is configured to be cracked or damaged in the same manner as the concrete when the strain is applied to the extent that the crack is generated in the concrete.

In the concrete member according to the present invention, a discharge port communicating with the detection pipe is provided on the surface of the body.

The concrete member crack detecting method according to the present invention is characterized in that, when the concrete is strained to such an extent as to cause cracking,
A hollow detection tube formed of a brittle material such as glass is buried in a concrete body so that a crack enters or breaks like the concrete, and then a detection liquid such as coloring ink is injected into the detection tube, Next, the state of exudation of the detection liquid on the surface of the skeleton is observed to detect the presence or absence and the position of occurrence of cracks on the surface.

[0010] In the concrete member and the method for detecting cracks according to the present invention, when a strain is generated in the concrete body, the same strain is also generated in the detector buried integrally with the concrete. Therefore, in the case where cracks occur in the surrounding concrete, the detection body formed of the brittle material is also damaged, and the detection liquid such as the coloring ink sealed therein flows out, and the detection body flows along the cracks in the concrete body. Seeps on the surface of the building.

[0011] Therefore, the cracks on the surface of the skeleton clearly emerge as a colored linear pattern, and the presence or absence and position thereof can be clearly detected even from a short distance.

Further, in the concrete member and the method for detecting cracks of the present invention, when a strain occurs in the concrete body, the same strain also occurs in the detection pipe buried integrally with the concrete, and the surrounding concrete cracks. In such a case, the detection tube formed of a brittle material is also damaged.

Therefore, if a detection liquid such as coloring ink is injected from the injection port communicating with the detection pipe in such a state, the detection liquid flows out from a damaged portion of the detection pipe and exudes to the surface of the concrete skeleton along cracks. I do.

Therefore, the cracks on the surface of the skeleton clearly appear as a colored linear pattern, and the presence or absence and the position thereof can be clearly detected even from a short distance.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a concrete member and a method for detecting cracks according to the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a vertical sectional view and a horizontal sectional view showing a concrete member according to a first embodiment. As can be seen from these figures, in the concrete member according to the present embodiment, the detection body 2 in which the detection liquid 3 such as coloring ink is sealed inside the hollow tube is buried in the concrete skeleton 1 in advance.

The detector 2 has an inner diameter of, for example, about several millimeters. When a strain is applied to the concrete so as to cause cracks, the detector 2 is cracked or damaged similarly to concrete so that the internal detection liquid 3 flows out. , Using a predetermined brittle material. Specifically, non-metallic inorganic materials such as glass and ceramics are preferable.

It is preferable that compressed gas 4 is also enclosed in the detector 2 so that when the detector 2 is damaged, the detection liquid 3 flows out of the damaged portion smoothly.

In order to manufacture such a concrete member,
After arranging the main bars 5 and the band bars 6, the detection body 2 is bound to, for example, the band bars 6, and then concrete is poured.

In the concrete member and the method for detecting cracks in the concrete embodiment of the present invention, when a strain is generated in the concrete frame 1, a similar strain is also generated in the detector 2 embedded in the concrete.

Therefore, for example, when cracks occur in concrete due to an earthquake, the detector 2 made of a brittle material is also damaged, and the detection liquid 3 enclosed therein flows out, and flows along the cracks in the concrete frame 1. Exudes to the surface of the skeleton.

Therefore, cracks in the concrete skeleton caused by the earthquake clearly appear on the surface of the skeleton as a colored linear pattern.

As described above, according to the concrete member of the present embodiment, when a crack occurs in a concrete skeleton due to an earthquake or the like, the crack can be clearly emerged as a colored linear pattern on the surface of the skeleton.

Therefore, it is possible to clearly detect the presence or absence of cracks and the position where the cracks occur even from a short distance, and to diagnose the degree of damage to concrete quickly and accurately.

Further, according to the present embodiment, since the compressed gas is sealed in the detection body, the detection liquid flows out smoothly from the damaged portion of the detection body. Therefore, even a minute crack can be easily found.

Although the concrete member is a pillar in the present embodiment, it is needless to say that the concrete member can be applied to any part such as a beam and a wall. Further, in the present embodiment, the detection body is arranged in parallel with the main reinforcement of the pillar. However, instead of or in addition to this, the detection body may be arranged in the horizontal direction.

Further, in the present embodiment, the detection gas is sealed in the detection body so that the detection liquid can flow out smoothly. Alternatively, the detection liquid tank communicating with the detection body may be replaced with a detection liquid tank, for example. May be buried above the tank, and a smooth outflow of the detection liquid may be achieved by utilizing a level difference between the tank and the damaged portion.

(Second Embodiment) Next, a second embodiment will be described. Note that components that are substantially the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

FIG. 2 is a vertical sectional view and a horizontal sectional view showing a concrete member according to the second embodiment. As can be seen from these drawings, the concrete member according to the present embodiment has a hollow detection pipe 12 embedded in a concrete skeleton 1 and an injection port 13 communicating with the detection pipe 12 provided on the surface of the skeleton. Sometimes it is closed with a stopper 14. The detection tube 12 has substantially the same configuration as the detection body 2 except that the detection liquid is not sealed therein, and a detailed description thereof will be omitted.

To manufacture such a concrete member,
As in the above embodiment, after the main reinforcement 5 and the stirrups 6 are arranged, the detection tube 12 is bound to, for example, the stirrups 6, and then concrete is poured.

In the concrete member and the method for detecting cracks of the concrete member according to the present embodiment, when a distortion occurs in the concrete skeleton 1, a similar distortion also occurs in the detection tube 12 embedded with the concrete. So, for example, if an earthquake cracks concrete,
The detection tube 12 formed of a brittle material is also damaged.

In such a state, as shown in FIG.
The detection liquid in the tank 21 is injected into the detection pipe 12 by operating the pump 22.

Then, the detection liquid flows out of the damaged portion of the detection tube 12 and exudes to the surface of the concrete skeleton along cracks of the skeleton. Then, the cracks in the concrete frame caused by the earthquake clearly appear on the surface of the frame as a colored linear pattern.

As described above, according to the concrete member and the method for detecting cracks of the concrete member of the present embodiment, when a crack occurs in the concrete frame due to an earthquake or the like,
The cracks can clearly appear on the surface of the skeleton as colored linear patterns.

Therefore, it is possible to clearly detect the presence or absence of cracks and the position where the cracks occur even from a short distance, and to diagnose the degree of damage to concrete quickly and accurately.

Further, according to the present embodiment, since the detection liquid accommodated in the tank is pumped by the pump, the detection liquid flows out smoothly from the damaged portion of the detection pipe, and is finely cracked. Can also be easily found.

In the present embodiment, the recovery of the injected detection liquid is not particularly mentioned. However, as shown in FIG. 4, a discharge port 33 communicating with the detection tube 12 is provided on the surface of the skeleton, and The detection liquid may be drawn out, and may be closed with the stopper 34 when not used.

According to such a configuration, the detection liquid injected from the injection port 13 can be withdrawn from the discharge port 33 and collected, and stored in the tank 21 for reuse. In addition, in the case of such a configuration, the pressure in the detection tube 12 may be maintained at a certain value or more by reducing the discharge flow rate from the discharge port 33. In this way, the detection liquid can be collected and circulated while checking for cracks.

[0039]

As described above, according to the concrete member and the method for detecting cracks of the concrete member according to the present invention, it is possible to find cracks in concrete at an early stage even if the distance is not very close.

[0040]

[0041]

[0042]

[Brief description of the drawings]

FIG. 1 is a view showing a concrete member according to a first embodiment, in which (a) is a vertical sectional view, and (b) is a horizontal sectional view along line AA.

FIGS. 2A and 2B are diagrams showing a concrete member according to a second embodiment, in which FIG. 2A is a vertical sectional view, and FIG. 2B is a horizontal sectional view along line BB.

FIG. 3 is a diagram showing an embodiment of a method for detecting a crack in a concrete member according to a second embodiment.

FIG. 4 is a diagram showing a modification of the concrete member according to the second embodiment and the state of implementation of a method for detecting cracks in the member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concrete frame 2 Detector 3 Detected liquid 12 Detector tube 13 Injection port 21 Detected liquid storage tank 22 Pump 33 Discharge port

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-134071 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 33/38 E04G 23/02 G01N 21 / 91

Claims (4)

(57) [Claims] 1. A detection body formed of a brittle material such as glass and filled with a detection liquid such as a coloring ink in a hollow interior is embedded in a concrete body, and the detection body has a degree of causing cracks in concrete. A concrete member characterized in that, when strain is applied, cracks are formed or broken similarly to the concrete and the detection liquid flows out, and a compressed gas is sealed in the detection body. 2. A concrete detection body having a hollow detection tube formed of a brittle material such as glass embedded therein, and an injection port communicating with the detection tube is provided on the surface of the concrete body. A concrete member characterized by being cracked or damaged similarly to the concrete when strain is applied to the extent that cracks are generated. 3. The concrete member according to claim 2, wherein a discharge port communicating with the detection pipe is provided on a surface of the skeleton. 4. A hollow detection tube made of a brittle material such as glass is buried in a concrete body so that when a strain is generated to the extent that cracks occur in the concrete, cracks are formed or broken like the concrete. Then, a detection liquid such as coloring ink is injected into the detection tube, and then the state of seepage of the detection liquid on the surface of the skeleton is observed to detect the presence or absence of a crack on the surface and the occurrence position. A method for detecting cracks in concrete members.