JP2001355343A - Concrete structure and method for repairing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete structure which can be visually confirmed with respect to progressive change of repaired portions thereof, or newly occurring deterioration and change, even after repairing of the structure. SOLUTION: The concrete structure includes a fibrous substrate having voids, which is bonded to the surface of the structure by means of a transparent or translucent adhesive, and therefore the surface of the concrete structure can be visually confirmed via the fibrous substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete structure in which a fiber base is bonded to the surface of a concrete structure, and a method for repairing a concrete structure in which a fiber base is bonded to the surface of a concrete structure.

[0002]

2. Description of the Related Art In a concrete structure, cracks, cracks, spalling, etc. occur in the concrete portion due to various factors such as cavities generated during construction, deterioration of the concrete structure itself, earthquakes, land subsidence, and the like.

When a crack reaches the outside of a concrete structure, the underground concrete structure causes groundwater to penetrate into the concrete structure, causing water leakage. When such cracks and cracks occur in the concrete structure, it is necessary to repair the concrete structure.

[0004] Repairs to a deteriorated concrete structure have conventionally been carried out by (1) overcoating or spraying a mortar on the surface of the deteriorated concrete structure to a thickness of about 5 to 10 cm, and (2) on the surface of the deteriorated concrete structure. A concrete structure is cast (thickened) about 30 cm thick. (3) A reinforcing fiber base material in which reinforcing fibers such as carbon fibers, glass fibers, and aramid fibers are arranged in one direction is made of a concrete using a room temperature curable resin such as an epoxy resin. (4) A reinforcing material such as a steel plate is attached to the surface of the concrete structure so as to be impregnated and bonded to the surface of the structure. Repair (reinforcement) or the like for filling the like is known.

[0005] However, although the above (1) can improve the surface of a concrete structure, it has a disadvantage that it is difficult to obtain a sufficient reinforcing effect. The above (2) can be expected to have a reinforcing effect, but the problem is that the volume of the concrete structure is increased by the thickness of the concrete to be cast, and that repairs are large and expensive, and regulations are required for construction. It has the drawback that it greatly affects daily activities.

In the above (3), a reinforcing effect can be expected,
Since the reinforcing fiber base used is a unidirectionally arranged base, at least two layers are impregnated and bonded, and there is a problem that the fiber arrangement direction of the reinforcing fiber base of each layer must be changed. In addition, when one or more layers of the reinforced fiber base material having been clogged are bonded using a usual adhesive, it is difficult to directly visually observe the surface of the repaired concrete structure.

In the above (4), a reinforcing effect can be expected,
There are drawbacks in that it takes time to process steel plates and the like, and that the repairs are quite large, requiring regulations for the construction, which greatly affects daily activities. Also, it is difficult to directly visually observe the surface of the repaired concrete structure. A disadvantage common to the above (1) to (4) is that it becomes difficult to directly visually observe the surface state of the concrete structure after repair.

As described above, since the surface of the original concrete structure could not be visually observed after the repair in the conventional repair, the surface of the concrete structure after the repair showed a serious deformation, It was difficult to identify any new significant deformations that occurred.

For this reason, in concrete structures such as tunnels, it is difficult to judge the necessity of re-repair of the concrete structure after the repair until a phenomenon such as peeling or collapse of the lining concrete occurs. It was a big social problem for safety.

When the fiber base material of the above (3) is impregnated and bonded to the surface of a concrete structure with a room temperature curable resin, a curable resin such as an epoxy resin is conventionally used. Even if the curing of the resin is slow and the bonding operation of the fiber base material is completed, there is a problem that the force for holding the fibers to the concrete structure cannot be secured until the resin is cured.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to repair a deteriorated concrete structure as described above, particularly a concrete structure such as a road or a railway tunnel. It is an object of the present invention to provide a concrete structure capable of confirming the progress of deformation or newly generated deterioration and deformation, and a method of repairing the same.

It is another object of the present invention to stably hold the fiber base material on the concrete structure by bonding the fiber base material to the surface of the concrete structure with an adhesive curable resin. An object of the present invention is to provide a concrete structure and a method for repairing the same, which can maintain a highly reliable adhesion of the fiber base material over a long period of time by using a resin.

Another object of the present invention is to provide a method for bonding a fiber base material to a concrete structure surface with an adhesive curable resin.
Even if the curable resin is not sufficiently cured, the fibers can be stably held on the surface of the concrete structure, and the synergistic effect of the curable resin and the embedded anchor allows a more reliable bonding of the fiber base material over the long term. An object of the present invention is to provide a concrete structure that can be maintained and a repair method thereof.

[0014]

That is, the present invention is characterized in that a fiber substrate is bonded to the surface of a concrete structure, and the surface of the concrete structure can be visually observed through the fiber substrate. It is a structure.

[0015] A concrete structure obtained by bonding the fiber base material to a concrete structure using an adhesive, or bonding the fiber base material to a concrete structure using an embedded anchor pin and an adhesive is used. preferable.

Further, the present invention provides a concrete structure characterized in that a fiber base material is adhered to the surface of the concrete structure using an adhesive, and after the bonding, the surface of the concrete structure can be visually observed through the fiber base material. Repair method.

Further, the present invention is characterized in that a fiber base material is bonded to the surface of a concrete structure using an embedded anchor pin and an adhesive, and the surface of the concrete structure can be visually observed through the fiber base material after bonding. This is a method for repairing concrete structures.

In the concrete structure and the method for repairing the same according to the present invention, it is preferable that the embedded anchor pin is fixed by using both mechanical fixing and adhesive fixing. It is preferable that the fiber base material has a space where the surface of the concrete structure can be visually observed. Preferably, the adhesive is transparent or translucent.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The concrete structure of the present invention is characterized in that the surface of the concrete structure can be visually observed through a fiber base material bonded to the surface of the concrete structure, and the fiber base material is provided with an adhesive or an embedded anchor pin and an adhesive. It is a concrete structure that is bonded to a concrete structure in combination.

The method for repairing a concrete structure according to the present invention is characterized in that the surface of the concrete structure can be visually observed through the bonded fiber substrate even after the fiber substrate is bonded to the surface of the concrete structure. In addition, the fiber base material is bonded to a concrete structure by using an adhesive or an embedded anchor pin and an adhesive together, and the embedded anchor pin is fixed by using both mechanical fixing and adhesive fixing. It is a repair method characterized by the following.

Next, the concrete structure according to the present invention,
The method for repairing a concrete structure will be described in detail with reference to the drawings. However, the present invention is not limited to these drawings, and the drawings are merely examples of the invention.

The fibrous base material used in the concrete structure of the present invention is one in which fiber bundles are arranged in a sheet shape in two directions (or multiple directions). FIG. 1 is a typical shape diagram showing one embodiment of a fiber base material used for a concrete structure of the present invention. In FIG. 1, a fiber base material 11 is obtained by arranging fiber bundles 1 in a sheet shape in two directions. There is a gap 2 having side lengths a and b between the arranged fiber bundles 1 and at least the side lengths a or b. One is not less than 2 mm and not more than the minimum width of the fiber base material.

FIG. 2 is a schematic view showing another embodiment of the fiber base material used for the concrete structure of the present invention. The fiber base material 11 shown in FIG. 2 is obtained by arranging the fiber bundles 1 in three directions, and the side lengths c, d, and e are provided between the arranged fiber bundles.
And at least one of the side lengths c, d or e is not less than 2 mm and not more than the minimum width of the fiber base material.

By using the fibrous base material having the shape shown in FIGS. 1 and 2, even after the fibrous base material is adhered to the surface of the concrete structure, cracks and cracks on the surface of the concrete structure are generated by the voids 2 in the fibrous base material. It becomes possible to visually observe the deformation such as.

The fiber bundle itself may be transparent or opaque. In the case of opacity, it is only necessary that there is a gap between the fiber bundles as described above and the fiber base material can be seen through. The material of the fiber base material may be any material having a reinforcing effect, such as carbon fiber, glass fiber, and aramid fiber.

The adhesive used in the present invention is preferably translucent or transparent.
It is particularly preferred that the visible light transmittance of the cured thickness body is larger than 0.1. By using such a transparent adhesive, even after the fiber base material is bonded to the surface of the concrete structure and reinforced (repaired), cracks and cracks on the surface of the concrete structure can be made through the fiber base material. Deformation can be directly visually observed.

Examples of the curable resin used as the adhesive include radical polymerizable resins such as epoxy resin, vinyl ester resin, unsaturated polyester resin, and (meth) acrylic resin.

Among these radically polymerizable resins,
In some cases, such as the repair of roads and railway tunnels, the completion of construction in a short time is required. In such a case, it is preferable to use a radically polymerizable resin that can be rapidly cured.

FIG. 3 is a typical shape diagram showing an embodiment of the anchor pin used in the concrete structure of the present invention. FIG. 3 shows a tapered embedded anchor pin as one example of the shape of the embedded anchor pin used in the repair method of the present invention. The embedded anchor pin is an expanded bottom anchor and is a general term for small anchors for mechanically fixing members without using bolts and nuts.

Referring to FIG. 3, the embedded anchor pin 30 having a tapered structure is provided with a bottom portion 37 for mechanical fixing to a concrete structure, a rod portion 38, and a washer 36 for holding and fixing the fiber base material to the concrete structure. And a pin 35 for expanding the bottom.

The rod diameter r1 and the head diameter r2 are generally r
1 <r2. The pore diameter R of the concrete structure is r1 <
When R <r2, the tapered embedded anchor pin combines the wedge effect of the widened portion with the wedge effect of the top portion, and the anchoring effect of the anchor pin to the concrete structure is enhanced.

If only mechanical fixing is performed, the pull-out strength may be reduced due to fatigue due to long-term repetitive load. Therefore, in order to securely fix the tapered embedded anchor pin to a concrete structure, it is necessary to fix the inside of the anchor fixing hole. Is preferably filled with a curable resin, and thereafter, an embedded anchor pin with a taper is driven in, the bottom is expanded, and both mechanical fixing and adhesive fixing are preferably used.

[0033] The concrete structure of the present invention can be carried out at a repair site of the concrete structure by a procedure of attaching the fiber base material to the surface of the concrete structure using the adhesive. In this case, there is basically no difference from the procedure of fiber reinforcement (repair) of a normal concrete structure.

The repairing method of the present invention can be carried out, for example, in the order of kelen treatment of a concrete structure, application of a primer for a concrete structure, and adhesion of a fiber base material using an adhesive.

In the procedure of bonding the fiber base material to the surface of the concrete structure, after applying the primer for the concrete structure to the surface of the concrete structure, when bonding the fiber base material, the unevenness is adjusted with a putty material or the like. When it is necessary, it is preferable to use a material having the same level of transparency as the adhesive of the present invention as the non-adjustment material used.

A primer having the same degree of transparency as the adhesive is used. Specifically, a primer such as "C Primer" (trade name, manufactured by Acrylic / Denki Kagaku Kogyo Co., Ltd.) is used. Can be used.

The method of bonding the fiber base material with the adhesive can be performed in the same manner as in the ordinary fiber reinforcement.
One example is an impregnation bonding method. The impregnation bonding method applies a primer, applies an adhesive as an undercoat to the surface of the hardened concrete structure, pastes a fiber base material thereon, impregnates the adhesive into the fiber base material with a rubber roller or a spatula, Further, it can be performed by a procedure of applying an adhesive on the fiber base material as a top coat.

The number of fibers to be adhered to the concrete structure is appropriately selected according to the required degree of reinforcement. However, the purpose of the present invention is to visually observe the surface of the concrete structure after construction. Make the range possible.

Further, in the case of the repair method using the embedded anchor pin of the present invention, after the bonding of the fiber base material,
As shown in FIG. 4, the concrete structure 40 has a diameter R (r
A hole 41 of 1 <R <r2) is made, and the embedded anchor pin 30 is driven in to expand the bottom.

When the adhesive fixing is also used, the curable resin 34 is filled and fixed in the space inside the hole 41 with the tapered embedded anchor pin. Drilling in the concrete structure may be performed at any time before or after bonding the fiber base material to the concrete structure. Filling of the curable resin 34 is performed before and after the tapered anchor pin is driven and expanded,
You can go at any time.

[0041]

Next, the details of a repair test conducted to confirm the effects of the present invention will be described with reference to examples.

Examples 1 to 3 and Comparative Examples 1 to 3 FIG. 5 is a schematic configuration diagram for explaining a visual observation test method for examining the effect of the concrete structure of the example of the present invention. FIG. 5A is a side view, and FIG. 5B is a plan view.

The concrete structure specimen used in the repair test was a commercially available concrete specimen of 10 cm × 10 cm × 40 cm, which was obtained by using a diamond cutter and measuring 10 cm × 10 cm × 2.
The cut surfaces 21a and 21b cut into two pieces each having a diameter of 0 cm are abutted with each other, and a steel wire 22 having a diameter of 0.5 mm is inserted as a spacer. , Epoxy resin adhesive) 31 was injected and cured and joined.

One surface of the concrete structure specimen was sandblasted, and a concrete structure primer 32 was applied and cured. Next, the aramid fiber base material 11 was bonded by the impregnation bonding method using the adhesive 33 to obtain a repaired concrete structure.

A load test was carried out to generate cracks on the surface of the repaired concrete structure specimen. Load test is universal tester (Autograph manufactured by Shimadzu Corporation)
Load bending test method using JIS (JIS A 110
6). Visual observation of the joints provided at intervals of 0.5 mm provided on the concrete structural specimen was performed before and during the load test.

Table 1 shows the aramid fiber base materials (3 types, AF-1 to AF-3), the primers for concrete structures (3 types, P-1 to P-3), and the adhesiveness used in the test. The agents (3 types, R-1 to R-3) are shown.

[0047]

[Table 1] The test results are shown in Table 2.

[0048]

[Table 2]

(Note) Evaluation of visual observation test ○: A gap of 0.5 mm or a new change (crack) on the surface of the concrete structure can be confirmed. Δ: It is difficult to confirm a gap of 0.5 mm or a new change (crack) on the surface of the concrete structure. X: A gap of 0.5 mm or a new change (crack) on the surface of the concrete structure cannot be confirmed.

As shown in Table 2, after bonding the fibrous base material to the concrete structure test specimen, a bonded gap of 0.5 mm on the surface of the concrete structure test specimen can be observed through the bonded fibrous base material, and the load is applied. Cracks on the surface of the concrete structure newly generated during the test were visually confirmed by combining the fiber base material (AF-3) of the present invention and the adhesives (R-1, R-2) of the present invention. Only the repaired specimen was found.

Example 4 Next, details of a test performed for confirming the effect of the anchor pin of the present invention will be described. FIG. 6 is a schematic configuration diagram for explaining a visual observation test method for examining the effect of the concrete structure of Example 4 of the present invention. FIG. 6A is a side view, and FIG. 6B is a plan view. As a concrete structure specimen used in the test, a ceiling surface (thickness: 12 cm) of a commercially available box culvert was used.

After sandblasting one surface of the concrete structure test specimen, applying a concrete structure primer 32 (using P-1 in Table 1) and curing, the adhesive 3
3 (using R-1), width 100 cm, length 100
cm of aramid fiber substrate 11 (using AF-1).

Before the adhesive hardens, the anchors of the aramid fiber substrate are anchored at 50 cm intervals into the anchor holes of φ65 mm × 80 mmL which have been drilled in the concrete structure specimen before bonding the aramid fiber substrate. A pin 30 (manufactured by Konishi Co., Ltd., CP-N670, fitted with a Bestem washer φ20 mm) was driven in, the tip was widened and fixed to a concrete structure specimen.

Using this test body, before the adhesive 33 was cured, air was blown from the blower 42 at an angle of 45 degrees to the end of the aramid fiber base material 11 as shown in FIG. The blowing rate was 80 m ² / min, and the change of the test specimen until the adhesive 33 was cured was observed. As a result, in the test body in which the aramid fiber substrate was fixed using the anchor pin, no peeling of the aramid fiber substrate was observed before the adhesive was cured.

Similarly, as shown in FIG. 8, when a blowing test was performed on a test piece without using an anchor pin, peeling occurred from the end of the fiber before the adhesive was cured, and finally all dropped. FIG. 8A is a side view, and FIG.
(B) is a plan view.

[0056]

As described above, in the concrete structure of the present invention, the surface state of the concrete structure can be visually observed even after the fiber base material is bonded, and the concrete structure after the fiber base material is bonded. The progress of the deformation of the surface of the object can be visually confirmed. Therefore, it is possible to take a countermeasure at an early stage before occurrence of an abnormal phenomenon such as peeling or collapse of the concrete structure after bonding the fiber base material. Further, even before the curable resin of the adhesive used for bonding the fiber base material is sufficiently hardened, the holding of the fiber base material to the concrete structure can be secured by the embedded anchor pin, and the adhesive and the embedded anchor pin can be retained for a long time. Holding stable fiber base material on concrete structure surface by synergistic effect of
That is, the reinforcement effect can be maintained.

[Brief description of the drawings]

FIG. 1 is a typical shape diagram showing one embodiment of a fiber base material used for a concrete structure of the present invention.

FIG. 2 is a shape diagram showing another embodiment of the fiber base material used for the concrete structure of the present invention.

FIG. 3 is a typical shape diagram showing an embodiment of an anchor pin used for a concrete structure of the present invention.

FIG. 4 is a conceptual diagram in which a fiber base material is held on a concrete structure of the present invention by using a tapered anchor pin, and further, adhesive fixing is used together with anchor fixing.

FIG. 5 is a schematic configuration diagram for explaining a visual observation test method for examining the effect of the concrete structure of the example of the present invention.

FIG. 6 is a schematic configuration diagram for explaining a visual observation test method for examining the effect of the concrete structure of Example 4 of the present invention.

FIG. 7 is an explanatory diagram showing a ventilation test of a concrete structure using an anchor pin according to Example 4 of the present invention.

FIG. 8 is a schematic diagram showing a test piece of a concrete structure without an anchor pin according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 Fiber bundles a to e Polygonal side length formed by voids between fiber bundles 11 Fiber base materials 21a, 21b Commercially available concrete (10 × 10 × 4
0 cm) bisected 22 steel wire 30 embedded anchor pin with taper 31 crack injection material 32 primer for concrete structure 33 adhesive 34 curable resin 35 member pin constituting tapered embedded anchor pin 36 washer 37 Enlarged bottom portion of tapered embedded anchor pin 38 Rod portion of tapered embedded anchor pin 39 Top of tapered embedded anchor pin 40 Concrete structure 41 Hole 42 Blower r1 Diameter of tapered embedded anchor pin rod portion r2 taper The diameter of the crown of the embedded anchor pin with a hole R The hole diameter for fixing the anchor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshihiro Ando 3-5-1 Asahicho, Machida-shi, Tokyo Denki Kagaku Kogyo Co., Ltd. Central Research Laboratory (72) Inventor Yoshinori Matsuda 2-2-2 Yoyogi, Shibuya-ku, Tokyo No.2 East Japan Railway Company (72) Inventor Toshihiko Niibori 2-2-2 Yoyogi, Shibuya-ku, Tokyo F-term in East Japan Railway Company 2E176 AA01 BB29

Claims (11)

[Claims] 1. A concrete structure wherein a fiber base material is adhered to the surface of the concrete structure, and the surface of the concrete structure can be visually observed through the fiber base material. 2. The concrete structure according to claim 1, wherein the fiber base material is bonded to the concrete structure using an adhesive. 3. The concrete structure according to claim 1, wherein the fibrous base material is bonded to the concrete structure using an embedded anchor pin and an adhesive. 4. The concrete structure according to claim 3, wherein said embedded anchor pin is fixed by using both mechanical fixing and adhesive fixing. 5. The concrete structure according to claim 1, wherein the fiber base material has a space in which the surface of the concrete structure can be visually observed. 6. The concrete structure according to claim 1, wherein the adhesive is transparent or translucent. 7. A method for repairing a concrete structure, comprising bonding a fiber substrate to the surface of the concrete structure using an adhesive, and allowing the surface of the concrete structure to be visually observed through the fiber substrate after the bonding. 8. A concrete structure wherein a fiber base material is bonded to the surface of a concrete structure using an embedded anchor pin and an adhesive, and the surface of the concrete structure can be visually observed through the fiber base material after bonding. How to repair things. 9. The method for repairing a concrete structure according to claim 8, wherein the embedded anchor pin is fixed by using both mechanical fixing and adhesive fixing. 10. The method for repairing a concrete structure according to claim 7, wherein the fiber base material has a gap in which the surface of the concrete structure can be visually observed. 11. The method for repairing a concrete structure according to claim 7, wherein the adhesive is transparent or translucent.