JP4574778B2 - Method for repairing concrete structure and surface coating formwork - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for repairing a concrete structure and a surface-covered formwork for simplifying the repair process.
[0002]
[Prior art]
Conventionally, a method for repairing deteriorated concrete is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-260716. In this repair method, after the deteriorated concrete is removed and the reinforcing bars are rusted, new reinforcing bars are welded to form a support base in a lattice shape. A wire mesh is affixed on the lattice reinforcing bars. Next, pipes are provided at two or three places on the top and bottom or the left and right as injection holes for injecting the foamed epoxy into the gap between the wire mesh and the concrete missing surface. Further, mortar or concrete is applied over the wire net to adjust the surface shape of a predetermined cross section. If mortar or the like is applied in such a state, it will not bite into the wire mesh and drop by its own weight. After the repair material of the surface covering portion of the reinforcing bar is cured and develops strength, the foamed epoxy is injected through the injection hole, and the FRP is attached to the outside of the repaired portion.
[0003]
[Problems to be solved by the invention]
However, the repair method described above requires three steps: a removal process for damaged / deteriorated parts, a repair process such as installation of reinforcing materials / formwork and concrete pouring, and a surface protection process as a finish. It was complicated. In particular, when concrete structures such as sewers and harbors are provided in places with severe environmental conditions, it is desired to simplify and improve the efficiency of concrete repair work.
[0004]
The present invention has been made in view of such circumstances, and does not require a reinforcing bar or a wire mesh. The repair process and the surface protection process are simultaneously performed to simplify and improve the process, and after repair. An object of the present invention is to provide a method for repairing a concrete structure and a surface-covered formwork that can extend the useful life.
[0005]
[Means for Solving the Problems]
The invention of the repair method for a concrete structure according to claim 1 includes a first plate-like body covering the surface of the concrete structure, and a high-strength fiber sheet affixed to the surface of the first plate-like body on the concrete structure side. A method of repairing a concrete structure using a surface-covered formwork having a surface covering so that an exposed surface exposed by the removal step and a high-strength fiber sheet face each other. A first attachment step of attaching the formwork to the concrete structure, and an injection step of injecting a restoration material between the exposed surface and the surface covering formwork, the surface covering formwork comprising a plurality of first plate-like bodies The first plate-like bodies adjacent to each other so as to be foldable, and the first plate-like bodies adjacent to each other can be folded together in a state where the first plate-like bodies are connected by the connection means. Strength fiber sheet Consists in part, take a step folding folding the surface coating formwork before the first mounting step, the structure including the development step of developing the surface-coated frame folded before the first mounting step.
[0006]
Thus, since the high-strength fiber sheet is affixed to the first plate-like body as a reinforcing material, the concrete structure can be repaired without requiring a reinforcing bar or a wire mesh as the reinforcing material. In addition, since the first plate-like body can be used as a surface protection material, a surface covering mold is attached, and a repair material such as cement mortar or resin mortar having high fluidity is provided in the gap between the exposed surface and the surface covering mold. If the injection is performed, the repair process is completed, and the time and labor for removing the mold can be saved. Therefore, the repair process and the protection process can be performed simultaneously, and the repair process can be simplified. Moreover, since strength is obtained by the high-strength fiber sheet, the weight of the mold can be reduced. As a result, it is possible to improve workability because it does not require a large support work as in the prior art, and it is only necessary to attach the temporary angle in the width direction of the surface coating formwork. Further, the cost can be reduced by simplifying the repair process.
[0008]
With this configuration, the surface coating mold can be folded and transported as necessary, and the surface coating mold folded in the vicinity of the repair site can be developed. For this reason, for example, in the repair work of the concrete wall of the sewer, it is possible to carry the work by bringing the surface-covered formwork folded from the manhole into the sewer and deploying it near the concrete wall that needs repair. Thus, repair work can be performed efficiently even in places where space is limited.
[0009]
According to a second aspect of the invention, in the repair method of claim 1 concrete structure according to the connecting means adopts a structure including a second mounting step of mounting a second plate member which covers the connecting means.
[0010]
With this configuration, the connecting means is covered by the second plate-like body, so that the surface of the connecting means can be protected and the surface of the surface-covered mold can be smoothed. Thereby, it becomes possible to make the influence received from a water flow as small as possible.
[0011]
The invention of a surface covering mold according to claim 3 is a surface covering mold that covers the surface of a concrete structure, and includes a plurality of first plate-like bodies and a concrete structure side of each first plate-like body. A high-strength fiber sheet affixed to the surface, and a connecting means for connecting the adjacent first plate-like bodies to each other in a foldable manner, the connecting means comprising a part of the high-strength fiber sheet, The structure which can be folded in the state with which 1 plate-shaped object was connected with the connection means is taken.
[0012]
Thus, since the high-strength fiber sheet is affixed to the first plate-like body as a reinforcing material, the concrete structure can be repaired without requiring a reinforcing bar or a wire mesh as the reinforcing material. In addition, since the first plate-like body can be used as a surface protective material, a surface covering mold is attached, and a restoration material such as cement mortar or resin mortar having high fluidity in the gap between the exposed surface and the surface covering mold Injecting can complete the repair process and save the labor of removing the formwork. Therefore, the repair process and the protection process can be performed simultaneously, and the repair process can be simplified. Moreover, since strength is obtained by the high-strength fiber sheet, the weight of the mold can be reduced. As a result, it is possible to improve workability because it does not require a large support work as in the prior art, and it is only necessary to attach the temporary angle in the width direction of the surface coating formwork. Further, since the surface covering mold can be folded, the surface covering mold can be folded and transported as necessary, and the surface covering mold folded in the vicinity of the repair site can be developed. For this reason, for example, in the repair work of the concrete wall of the sewer, it is possible to carry the work by bringing the surface-covered formwork folded from the manhole into the sewer and deploying it near the concrete wall that needs repair. Thus, repair work can be performed efficiently even in places where space is limited.
[0013]
According to a fifth aspect of the present invention, in the surface-covered mold according to any one of the third or fourth aspect , the second plate-like body that covers the connecting means is further provided on the connecting means.
[0014]
With this configuration, the connecting means is covered by the second plate-like body, so that the surface of the connecting means can be protected and the surface of the surface-covered mold can be smoothed. Thereby, it becomes possible to make the influence received from a water flow as small as possible.
[0015]
According to a fourth aspect of the present invention, in the surface-covered mold according to the third aspect , the first plate-like body is configured by acid-resistant FRP. A sixth aspect of the present invention is the surface-coated mold according to the fifth aspect , wherein the second plate-like body is formed of acid-resistant FRP.
[0016]
With this configuration, the concrete surface can be protected by acid-resistant FRP, so that the service life of the frame can be prolonged.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.
[0018]
FIG. 1 is a flowchart showing the steps of a concrete structure repair method according to an embodiment of the present invention. First, a field survey is performed (step S1). Here, the deteriorated part of the concrete structure is detected, and the cross-sectional dimension of the deteriorated concrete and the removal thickness of the deteriorated part are measured. Next, the surface coating formwork according to the present embodiment is manufactured in a quality-controlled factory (step S2). This surface coating mold will be described with reference to FIG.
[0019]
Fig.2 (a) is a top view of the surface coating formwork which concerns on this Embodiment, FIG.2 (b) is the same sectional drawing. This plan view shows the surface side of the surface covering mold 1, and the back side of the surface covering mold 1 faces a concrete structure (not shown). The surface covering mold 1 has an acid-resistant first FRP board 2 as a first plate-like body on the surface side. The first FRP board 2 is provided with a glass fiber sheet (not shown) in a triaxial direction. The size of the first FRP board 2 is, for example, 3000 mm in length, 300 mm in width, and 12 mm in thickness. In addition, the surface of the 1st FRP board 2 can also prevent the damage at the time of conveyance by performing a vinyl film process.
[0020]
Moreover, as shown in FIG.2 (b), the bi-directional aramid fiber sheet 3 as a high intensity | strength fiber sheet is affixed on the back surface of the 1st FRP board 2. As shown in FIG. The aramid fiber sheet 3 is obtained by converting an aromatic polyamide into a fiber, and has a feature of high strength and light weight. In the present embodiment, for example, a bi-directional aramid fiber sheet having a tensile strength of 392.266 [kN] (40 t) is used. This aramid fiber sheet 3 also functions as a connecting means for the first FRP board 2. That is, in the present embodiment, three first FRP boards 2 are arranged at a predetermined interval, and the aramid fiber sheet 3 is pasted from the back surface, so that the connecting portion 3a composed of the unimpregnated portion of the aramid fiber sheet is 3 The first FRP boards 2 are connected. As a result, the three first FRP boards 2 can be folded. A second FRP board 4 as a second plate-like body formed by acid-resistant FRP is attached to the surface of the connecting portion 3a. The surface of the connecting portion 3a where the first FRP board 2 does not exist is protected by the second FRP board 4.
[0021]
As described above, the surface-covered mold according to the present embodiment can be folded and transported as necessary, and the surface-covered mold folded in the field can be developed. For this reason, for example, in the repair work of the concrete wall of the sewer, it is possible to carry the work by bringing the surface-covered formwork folded from the manhole into the sewer and deploying it near the concrete wall that needs repair. Thus, repair work can be performed efficiently even in places where space is limited.
[0022]
On the surface of the first FRP board 2, there are provided injection holes (not shown) for injecting a restoration material and extracting air, and on the surfaces of the first FRP board 2 and the second FRP board 4, the concrete structure is surface-coated. Bolt holes 6 for fixing the mold 1 are provided.
[0023]
The design condition of the first FRP board 2 can be determined as follows, for example. First, considering that the restoration material is injected at an injection pressure of 49033.25 Pa (0.5 kgf / cm ² ) and the dead weight of the injection mortar, the deflection amount of the first FRP board 2 is targeted at a maximum of 5 mm. . Moreover, the intensity | strength by the aramid fiber sheet affixed on the back surface side of the 1st FRP board 2, ie, the side facing a concrete structure, is considered. Next, the anchor bolt pitch is 500 mm with respect to the longitudinal direction of the first FRP board 2. The glass fiber reinforcement is designed on the basis of a 4-axis assembly fabric.
[0024]
As a design condition for acid resistance, acid glass is used as the glass fiber used for the surface layer of the first FRP board 2. The laminated resin has two levels of unsaturated polyester and vinyl ester in consideration of acid resistance. Note that the design condition of the second FRP board 4 conforms to the design condition of the first FRP board 2.
[0025]
In the present embodiment, the surface covering mold 1 is formed by hand lay-up, but it may be formed by mechanical molding.
[0026]
Thus, since the high-strength fiber sheet is affixed to the first plate-like body as a reinforcing material, the concrete structure can be repaired without requiring a reinforcing bar or a wire mesh as the reinforcing material. In addition, since the first plate-like body can be used as a surface protection material, a surface covering mold is attached, and a repair material such as cement mortar or resin mortar having high fluidity is provided in the gap between the exposed surface and the surface covering mold. If the injection is performed, the repair process is completed, and the time and labor for removing the mold can be saved. Therefore, the repair process and the protection process can be performed simultaneously, and the repair process can be simplified. Moreover, since strength is obtained by the high-strength fiber sheet, the weight of the mold can be reduced. As a result, it is possible to improve workability because it does not require a large support work as in the prior art, and it is only necessary to attach the temporary angle in the width direction of the surface coating formwork. Further, the cost can be reduced by simplifying the repair process.
[0027]
Moreover, since the concrete surface can be protected by acid-resistant FRP, it becomes possible to prolong the service life of the frame.
[0028]
Next, a removal process for removing the deteriorated concrete detected in the concrete structure is performed after or at the same time as the production of the surface covering formwork in step S2 (step S3). In the removal process, “hanging work” is performed with ultra-high pressure water. The water pressure is set to, for example, 196.133 [MPa] (2000 kgf / cm ² ). Next, the surface covering mold produced in step S2 is folded and carried to the site (step S4). Since the surface covering formwork according to the present embodiment can be folded as described above, for example, when repairing a concrete wall surface of a sewer, it can be carried in from a narrow entrance such as a manhole. That is, the manhole has a diameter of 600 mm, and the first FRP board 2 has a width of 350 mm as described above, so that it can be carried into the sewer from the manhole by folding the surface coating formwork. Become.
[0029]
Next, at the repair site, the folded surface covering mold is unfolded, and this surface covering mold is attached to the exposed surface exposed by removing the deteriorated concrete (step S5). That is, the connecting portion 3a in the surface coating mold is fixed with a concrete anchor grip, and impregnated with an underwater curing type epoxy resin grout material. After impregnation, the second FRP board 4 is temporarily fixed on the connecting portion 3a. This state will be described with reference to FIGS.
[0030]
FIG. 3 is a cross-sectional view showing a state in which the surface covering mold according to the present embodiment is attached on the exposed surface exposed by the removal process. 4 is a cross-sectional view of the surface-covered mold taken along line 1-1 in FIG. 3, and FIG. 5 is a cross-sectional view of the surface-covered mold cut along line 2-2 in FIG. A concrete anchor grip 8 is provided on the exposed surface 9 of the concrete structure. A bolt 10 is screwed into the concrete anchor grip 8 through a bolt hole 6 provided in the second FRP board 4. Thereby, the surface covering mold 1 is fixed on the exposed surface 9. Further, the temporary angle 11 is fixed to the first FRP board 2 by a bolt 12 and a nut 13. Moreover, on the aramid fiber sheet 3, in order to improve the adhesiveness of a restoration material, the fine aggregate 14 is spread | dispersed. When the surface covering mold 1 is attached, a gap 15 exists between the aramid fiber sheet 3 and the exposed surface 9.
[0031]
Thus, since the connection part 3a is coat | covered with the 2nd FRP board 4, while the surface of the connection part 3a is protected, the surface of the surface coating formwork 1 can be smoothed. Thereby, it becomes possible to make the influence received from a water flow as small as possible.
[0032]
When the attachment of the surface coating mold is finished, the end of the board is sealed with an underwater curing type epoxy resin sealing material (step S6), and cement-based non-shrink mortar as a restoration material is injected from an injection hole (not shown) (step S7). . When the gap 15 is filled with the restoration material, it is cured for 24 hours or more until a predetermined strength is obtained (step S8).
[0033]
As described above, since the surface covering mold can be attached using the bolts 10 and 12 and the temporary angle 11, when the surface covering mold 1 is attached and when the restoration material is injected, a large-scale support work as in the past can be performed. It is not necessary, and the repair process can be simplified.
[0034]
Next, the bolts 10 and 12 are removed, and stainless or plastic countersunk bolts 17 and 18 are attached (step S9). Thus, since the unevenness | corrugation of the surface of a surface covering formwork can be eliminated by using the countersunk bolts 17 and 18, and it can be set as a state close | similar to a plane, it becomes possible to avoid the defect | deletion by a water flow etc., for example. The countersunk bolts 17 and 18 may be formed of a material having acid resistance, and the material is not limited to stainless steel or plastic.
[0035]
Finally, if a vinyl film is applied on the surface, it is removed and completed (step S10). FIG. 6 is a diagram showing a state when the repair is completed in the present embodiment. The space between the surface covering mold 1 and the exposed surface 9 is filled with the restoration material 16. Further, since the countersunk bolts 17 and 18 are used, the surface of the surface-covered mold 1 is not uneven.
[0036]
As described above, the surface-covered mold according to the present embodiment has high-strength aramid fibers attached to the plate-like body as a reinforcing material, so that it does not require a reinforcing bar or a wire mesh as a reinforcing material. You can repair things. Further, since the plate-like body can be used as a surface protection material, if the surface-covered mold is attached and the repair material is injected into the gap between the exposed surface and the surface-covered mold, the repair process is completed and the mold is removed. Save time and effort. Therefore, the repair process and the protection process can be performed simultaneously, and the repair process can be simplified. Moreover, since strength is obtained by the aramid fiber, the weight of the mold can be reduced. As a result, it is possible to improve workability because it does not require a large support work as in the prior art, and it is only necessary to attach the temporary angle in the width direction of the surface coating formwork. Further, the cost can be reduced by simplifying the repair process.
[0037]
As described above, in the present embodiment, the surface-covered formwork on which the aramid fiber sheet is affixed as the reinforcing material of the FRP board has been described as an example. However, the high-strength fiber sheet according to the present invention is limited to the aramid fiber sheet. is not. That is, it is also possible to use other materials having strength corresponding to the strength of aramid fibers, such as carbon fiber, vinylon, iron (lass) wire mesh, and the like.
[0038]
【The invention's effect】
As described above, the present invention is a surface covering having a first plate-like body covering the surface of a concrete structure and a high-strength fiber sheet affixed to the surface of the first plate-like body on the concrete structure side. A method of repairing a concrete structure using a formwork, in which the surface covering formwork is made into a concrete structure so that the exposed surface exposed by the removal process and the high-strength fiber sheet face each other. A configuration including a first attachment step of attaching to an object and an injection step of injecting a restoration material between the exposed surface and the surface coating mold is adopted. Thus, since the high-strength fiber sheet is affixed to the first plate-like body as a reinforcing material, the concrete structure can be repaired without requiring a reinforcing bar or a wire mesh as the reinforcing material. In addition, since the first plate-like body can be used as a surface protection material, a surface covering mold is attached, and a repair material such as cement mortar or resin mortar having high fluidity is provided in the gap between the exposed surface and the surface covering mold. If the injection is performed, the repair process is completed, and the time and labor for removing the mold can be saved. Therefore, the repair process and the protection process can be performed simultaneously, and the repair process can be simplified. Moreover, since strength is obtained by the high-strength fiber sheet, the weight of the mold can be reduced. As a result, it is possible to improve workability because it does not require a large support work as in the prior art, and it is only necessary to attach the temporary angle in the width direction of the surface coating formwork. Further, the cost can be reduced by simplifying the repair process.
[Brief description of the drawings]
FIG. 1 is a flowchart showing steps of a concrete structure repair method according to an embodiment of the present invention.
FIG. 2A is a plan view of a surface covering mold according to the embodiment.
(B) It is sectional drawing of the surface coating formwork which concerns on the said embodiment.
FIG. 3 is a cross-sectional view showing a state in which the surface covering mold according to the embodiment is attached on the exposed surface exposed by the removal process.
4 is a cross-sectional view of the surface coating mold taken along line 1-1 in FIG. 3;
FIG. 5 is a cross-sectional view of the surface coating mold taken along line 2-2 in FIG.
FIG. 6 is a diagram showing a state when repair is completed in the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Surface coating formwork, 2 ... 1st FRP board, 3 ... Aramid fiber sheet, 3a ... Connection part, 4 ... 2nd FRP board, 6 ... Bolt hole, 8 ... Concrete anchor grip, 9 ... Exposed surface, 10 ... Bolt, DESCRIPTION OF SYMBOLS 11 ... Temporary angle, 12 ... Bolt, 13 ... Nut, 14 ... Fine aggregate, 16 ... Restoration material, 17 ... Countersunk bolt, 18 ... Countersunk bolt

Claims (6)

Concrete structure using a surface covering formwork having a first plate-like body covering the surface of a concrete structure and a high-strength fiber sheet affixed to the surface of the first plate-like body on the concrete structure side Repair method,
A removal process for removing the deteriorated concrete;
A first attachment step of attaching the surface covering formwork to the concrete structure such that the exposed surface exposed by the removal step and the high-strength fiber sheet face each other;
An injection step of injecting a restoration material between the exposed surface and the surface-covered mold,
The surface-covered formwork includes a plurality of the first plate-like bodies and connecting means for foldably connecting the adjacent first plate-like bodies, and the adjacent first plate-like bodies are connected to each other. It can be folded in a state of being connected by a connecting means,
The connecting means comprises a part of the high-strength fiber sheet,
A folding step of folding the surface-covered mold before the first attachment step;
A method for repairing a concrete structure, comprising: a step of unfolding the folded surface covering formwork before the first attachment step. On said coupling means, repairing method according to claim 1 concrete structure according, characterized in that it comprises a second mounting step of mounting a second plate member for covering the connecting means. A surface-covered formwork that covers the surface of a concrete structure,
A plurality of first plates,
A high-strength fiber sheet affixed to the surface of the first plate-like body on the concrete structure side;
A connecting means for connecting the adjacent first plate-like bodies in a foldable manner;
The connecting means comprises a part of the high-strength fiber sheet,
The surface-covered formwork, which is foldable in a state where the adjacent first plate-like bodies are connected by the connecting means. The surface-coated mold according to claim 3, wherein the first plate-like body is formed of acid-resistant FRP. 5. The surface-covered formwork according to claim 3 , further comprising a second plate-like body that covers the connection means on the connection means. The surface-coated mold according to claim 5, wherein the second plate-like body is formed of acid-resistant FRP.

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