KR102626379B1 - Concrete structure using textile reinforcement and cement mortar of spray type, and method for strengthening for the same - Google Patents

Abstract

When repairing and reinforcing a concrete structure by fixing the textile reinforcement material on the surface of the concrete structure in advance and spraying cement mortar on it using a grid fixing device, the final goal is to use a thickness guide when the worker sprays the cement mortar in multiple stages. A concrete structure and its repair and reinforcement method using textile reinforcement and spray-type cement mortar that can measure the thickness and thus precisely construct spray-type cement mortar are provided.

Description

Concrete structures and their repair and reinforcement method using textile reinforcement and spray-type cement mortar {CONCRETE STRUCTURE USING TEXTILE REINFORCEMENT AND CEMENT MORTAR OF SPRAY TYPE, AND METHOD FOR STRENGTHENING FOR THE SAME}

The present invention relates to a repair and reinforcement method for concrete structures. More specifically, when repairing and reinforcing concrete structures using textile reinforcement and cement mortar (or dry mortar), a cement mortar composition for spraying is formed and a grid fixing device is used. It relates to concrete structures and their repair and reinforcement methods for fixing carbon fiber grids, which are textile reinforcements.

Typically, grid-type geogrid (hereinafter referred to as “grid”) is a reinforcing material used for purposes such as retaining wall reinforcement, slope reinforcement, and ground reinforcement during civil engineering construction. In addition to properties such as construction resistance and friction characteristics, these grids require high tensile strength and low tensile strain (low elongation) for their use.

As a method of manufacturing such a grid, a method is generally used in which plastic is injected or extruded, holes are drilled at predetermined intervals, and then uniaxially or biaxially stretched. However, grids using injected plastic have low tensile strength, are difficult to manufacture through a continuous process, and are subject to limitations in size and shape.

Recently, textile grid fabrics have been prepared by weaving or knitting them into a grid-shaped fabric using high-strength fibers, and then the surface is covered with a resin coating solution such as polyvinyl chloride, bitumen, acrylic, latex, and rubber-based resin, and then high-temperature heat treatment. Textile Grid Reinforcement manufactured through is being effectively used in the construction and reinforcement of concrete structures.

Because these textile grid reinforcements use high-strength fibers compared to plastic grid reinforcements, they exhibit high tensile strength and low tensile strain, and thus exhibit excellent structural material properties for building and reinforcing structures.

FIG. 1 is a drawing for specifically explaining a textile grid reinforcement, where a) in FIG. 1 shows a textile grid reinforcement, and b) in FIG. 1 shows a textile grid reinforcement produced by a weaving method.

As shown in a) of FIG. 1, the textile grid reinforcement 10 is made by weaving or knitting into a grid-shaped fabric using high-strength fibers such as carbon fiber and aramid fiber, thereby producing a textile grid. The textile grid reinforcement material (10) is manufactured by impregnating it with epoxy, polyester, acrylate, SBR resin, etc.

This textile grid reinforcement 10 is composed of a weft (10a) and a warp (10b), as shown in b) of FIG. 1, and each of the weft (10a) and the warp (10b) is a fiber bundle. Although (11) and resin (12) are impregnated, the completed textile grid reinforcement (10) is ductile enough to be wound into a roll. Since the textile grid reinforcement 10 produced by this weaving method is woven by twisting the warp yarn 10b, it has the characteristic of having a greater elongation in the warp direction compared to the weft direction of the weft yarn 10a, which is arranged in a straight line as the main direction.

Meanwhile, Figure 2 is a view illustrating the front and side views on which textile grid reinforcement according to the prior art is mounted.

As shown in Figure 2, in the case of a repair/reinforcement method using textile grid reinforcement and concrete, a plurality of anchors 20 are installed after drilling the surface of the concrete structure, and the textile grid reinforcement 10 is attached to a fixing device ( 30), then construct concrete. This repair/reinforcement method has the advantage of being able to precisely mount the textile grid 10, but has the disadvantage of low anchor construction speed and low concrete construction quality on the back of the textile grid reinforcement due to rebound during concrete placement.

Meanwhile, Figure 3 is a photograph illustrating a mortar spray method according to the prior art.

As shown in Figure 3, the mortar spray method according to the prior art is for repairing damaged concrete structures. In order to reduce the amount of dust and rebound, a small amount of water is added to the powder material in advance and then a fixed amount is sprayed from the nozzle just before spraying. This is a repair method in which water is mixed again and sprayed.

This spray method is divided into dry-mix process and wet-mix process depending on the production process and construction process. Specifically, the dry spray method is a method of dry mixing cement and air-dried aggregate, adding an accelerator and supplying it to a spray device, compressing it through a hose with compressed air, and spraying it from a nozzle.

At this time, the mixing water is mixed with the aggregate within the nozzle and is sprayed and attached to the construction surface at high speed.

In addition, the wet spray method, which is divided into the air pressure method and the screw pump pressure method, mixes all the materials by adding water, supplies it to the spray device, adds more air from the nozzle, increases the spray speed, and sprays it. In particular, the pneumatic wet spray method involves pumping wet-mixed mortar with compressed air and spraying it by adding an accelerator from the nozzle. There are wet chamber type and wet screw type.

Meanwhile, as mentioned above, grids of various shapes are used as reinforcing materials in the construction or repair and reinforcement of structures, external insulation of buildings, and pavement construction, but they are constructed without separate spacers or fixing devices to mount and fix these grid reinforcements. .

In addition, the grid used with various binders during the construction or repair and reinforcement of structures, external insulation of building exterior walls, and pavement construction serves as a reinforcing material, so it is very important to maintain not only the horizontal position but also the vertical position during construction. In particular, since the grid is provided with reinforcing materials to cope with the tensile stress occurring in the matrix (in a solid state of the binder), maintaining a horizontally taut state without deformation is advantageous in terms of reinforcing effect and matrix crack control.

However, according to the conventional technology, precise construction of the grid was difficult because there was no separate grid fixing device, and problems such as falling off from the object during construction also occurred.

In addition, deformation occurred due to construction and compaction pressure of binders such as concrete, mortar, asphalt, and elastic rubber packaging materials laid after grid placement, making it difficult to secure construction quality.

Meanwhile, in order to solve the above-described problem, a method of fixing the textile grid reinforcement to the surface by attaching an anchor has been disclosed as a method of fixing the textile grid reinforcement according to the prior art.

For example, Republic of Korea Patent No. 10-2096032, registered as a patent application by the applicant and inventor of the present invention, is entitled “Anchor pin for pouring shotcrete and fixing textile grid, and method of constructing shotcrete for reinforcing textile grid using the same.” The invention of the name is disclosed, and a type anchor for fixing a grid is disclosed.

In addition, Republic of Korea Patent No. 10-2404786, registered as a patent application by the applicant and inventor of the present invention, discloses an invention titled “Fixing device for textile grid reinforcement and construction method thereof,” see Figure 4. This explains.

Figure 4 is a construction example of a textile grid reinforcement, a grid fixing device, and a finishing layer using a fixing device for textile grid reinforcement according to the prior art.

Referring to Figure 4, the fixing device for textile grid reinforcement according to the prior art is a grid fixing device ( It is a fixing device for the textile grid reinforcement that is fixed and installed by the anchor pin (31a) of 31), and the fixing device for the textile grid reinforcement includes a detachable guide (32) and a tableting device (33).

The detachable guide 32 includes a guide washer 32a and a guide magazine 32b, and a grid fixture 31 is attached to one side of the sheet-shaped guide magazine 32b, and a guide is attached to the other side of the guide magazine 32b. A washer (32a) is attached.

The tableting device 33 is guided by magnetic force to the guide washer 32a, and the internal anchor pin 31a is connected to the guide washer 32a of the detachable guide 32, the guide magazine 32b, and the grid fixing device 31. Penetrate so that the tip is embedded in the structure 41.

The detachable guide 32 allows reuse by separating it from the attached grid fixture 31 after the textile grid reinforcement 43 is fixed and installed on the structure 41, and the guide washer of the detachable guide 32 ( 32a) is a ring member in the form of a ring member in which the extended tableting portion 33a of the tableting device 33 is guided by magnetic force and has a through hole through which the anchor pin 31a passes, and is provided on the other side of the guide magazine 32b. are attached and spaced apart.

Here, the structure 41 has a surface finishing layer 42 formed on the surface, and the textile grid reinforcement 43 is fixed and installed on the surface finishing layer 42 by the grid fixing device 31 and the tableting device 33. The anchor pin (31a) is installed by penetrating the surface finishing layer (42) and having its tip driven into the structure (41).

The textile grid reinforcement (43) is set on the structure (41) using the grid fixing device (31) and the detachable guide (33), and is then set to the structure (41) using the anchor pin (31a) by the tableting device (33). 41), and is embedded in the finishing layer 44 to serve as a grid-shaped reinforcement to reinforce the structure 41.

In addition, the grid fixing device 31 is formed so as to contact the textile grid reinforcement 43 formed in a grid shape, and includes a retaining clip attached to one side of the sheet-shaped guide magazine 32b; and a spacer formed integrally with the retaining clip. The spacer is installed to penetrate the grid hole of the textile grid reinforcement 42 and come into contact with the structure 41 so that the textile grid reinforcement 43 is spaced apart from the surface of the structure 41. It is set as fixed as possible.

In addition, the anchor pin (31a) of the grid fixing device (31) penetrates the guide washer (32a) of the detachable guide (32) and the through hole of the sheet-shaped guide magazine (32b), and then is connected to the grid fixing device (31). ) and the tip is typed into the structure 41 by passing through the first through hole formed in the retaining clip and the second through hole formed in the spacer. The textile grid reinforcement 42 may be fixedly installed on the structure 41.

According to the conventional technology for fixing the textile grid reinforcement, the textile grid reinforcement is set on the surface of the structure with the fixing device for the textile grid reinforcement, and then the anchor pin is accurately penetrated through the fixing device for the textile grid reinforcement, and a guide washer is used to fix it. Because it uses a detachable guide that includes a guide magazine in the form of a sheet, the worker's work efficiency can be maximized and the textile grid reinforcement can be quickly fixed and installed on the structure.

In addition, a detachable guide including a guide washer and a sheet-type guide magazine can accurately drive anchor pins into a desired position and direction using a tableting device.

Meanwhile, Figure 5 is a side view showing a fixing position for installing a grid fixing device on a concrete structure when using a grid fixing device according to the prior art.

As shown in FIG. 5, when using a grid fixture, there is the inconvenience of having to mark the fixing position 50a for installing the grid fixture on the concrete structure 50.

As described above, a concrete structure repair or reinforcement method using a textile grid reinforcement and an inorganic binder according to the prior art has been disclosed.

However, in the concrete structure repair or reinforcement method according to the conventional technology, first, it is difficult to precisely fix the textile at the construction site, and second, when constructing cement mortar using the spray method, hoses or nozzles become clogged and rebound occurs. occurred excessively, and thirdly, when constructing using the spray method, there is a problem that it is difficult to accurately determine the required construction thickness of cement mortar during construction.

Republic of Korea Patent No. 10-2404786 (registration date: May 27, 2022), title of invention: “Fixing device for textile grid reinforcement and construction method thereof” Republic of Korea Patent No. 10-2286562 (registration date: July 30, 2021), title of invention: “Grid fixing device with spacer-integrated retaining clip for grid reinforcement and grid fixing method using the same” Republic of Korea Patent No. 10-2096032 (registration date: March 26, 2020), title of invention: “Anchor pin for pouring shotcrete and fixing textile grid, and method of constructing shotcrete reinforcing textile grid using the same” Japanese Patent No. 4,209,714 (registration date: October 31, 2008), title of invention: “Surface protection method for concrete concrete” Japanese Registered Utility Model No. 7-6198 (Registration Date: February 15, 1995), Title of Invention: “Detection pin for construction of beopbeop surface”

The technical problem to be achieved by the present invention to solve the above-described problems is to repair and reinforce the concrete structure by fixing the textile reinforcement material on the surface of the concrete structure in advance and spraying cement mortar on it using a grid fixing device, The purpose is to provide a concrete structure and its repair and reinforcement method using textile reinforcement and spray-type cement mortar, which allows workers to estimate the final target thickness by using a thickness guide when spraying cement mortar in multiple stages.

Another technical problem to be achieved by the present invention is that when fixing a textile grid to a concrete structure to be repaired, there is no need to mark the fixing position in advance on the concrete structure to be repaired, and the grid is firmly maintained on the surface to be adhered by precisely maintaining the fixing interval. The purpose is to provide a concrete structure and its repair and reinforcement method using fixable textile reinforcement and spray-type cement mortar.

Another technical problem to be achieved by the present invention is that when constructing a cement mortar composition using a spray method, there is no clogging of the hose or nozzle, there is no waste of material because the rebound amount is small, and the compressive strength, bending strength, and adhesion strength are all excellent. The purpose is to provide a concrete structure and its repair and reinforcement method using textile reinforcement and spray-type cement mortar, which can firmly repair or reinforce the concrete structure.

As a means of achieving the above-mentioned technical problem, the repair and reinforcement method of a concrete structure using a textile reinforcement material and a spray-type cement mortar according to the present invention includes: a) placing a textile grid, which is a textile reinforcement material, on the adhered surface of the concrete structure to be repaired; steps; b) arranging the body of the grid fixture in which the spacing member, cover plate, and thickness guide are combined, at predetermined vertical and horizontal intervals on the adhered surface of the concrete structure to be repaired; c) fixing the body of the grid fixing device to the concrete structure to be repaired by inserting a fixing pin through a first through hole formed in the center of the cover plate of the grid fixing device; and d) constructing cement mortar by spraying on the adhesion surface of the repaired concrete structure on which installation of the grid fixing device has been completed; wherein the construction thickness of the cement mortar for spraying is determined through the thickness guide of the grid fixing device. Construct the cement mortar by spraying while checking, and the cement mortar for spraying by spraying includes 100 parts by weight of binder (B) formed of cement mortar or dry mortar; 110 to 120 parts by weight of fine aggregate, which is sand; 2.5 to 3.2 parts by weight of a high-performance water reducing agent; Liquid admixture, a liquid functional chemical admixture; and 56 to 72 parts by weight of water (W), and mixed with 0.7 to 1.0 parts by weight of reinforcing fiber.
In addition, as a means of achieving the above-mentioned technical problem, the concrete structure using textile reinforcement and spray-type cement mortar according to the present invention is concrete using textile reinforcement and spray-type cement mortar constructed using a grid fixing device. As a structure, the grid fixing device includes: a gap maintenance member in close contact with the adhered surface of the concrete structure to be repaired so as to maintain a predetermined gap with the adhered surface; A cover plate integrated on the upper part of the gap maintenance material and arranged to cover the textile grid disposed on the adhered surface of the concrete structure to be repaired; A thickness guide that has a predetermined protrusion length and is fastened to the second through hole (h2) formed on one side of the cover plate to check the construction thickness of the spray cement mortar applied by spraying on the adhered surface of the repaired concrete structure. ; And a fixing pin that is typed through a first through hole (h1) formed in the center of the body of the grid fixing device and fixes the body of the grid fixing device to the concrete structure to be repaired; including, the spray cement mortar is 100 parts by weight of binder (B) formed of cement mortar or dry mortar; 110 to 120 parts by weight of fine aggregate, which is sand; 2.5 to 3.2 parts by weight of a high-performance water reducing agent; Liquid admixture, a liquid functional chemical admixture; and 56 to 72 parts by weight of water (W), and mixed with 0.7 to 1.0 parts by weight of reinforcing fiber. The cement mortar is applied by spraying in one or multiple stages on the adhered surface of the concrete structure to be repaired. I do it.

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According to the present invention, when a textile reinforcement is fixed to the surface of a concrete structure in advance and the concrete structure is repaired and reinforced by spraying cement mortar on it using a grid fixing device, a thickness guide is provided when the worker sprays the cement mortar in multiple stages. By using , the final target thickness can be estimated, and accordingly, cement mortar for spraying can be precisely constructed.

According to the present invention, when fixing a textile grid to a concrete structure to be repaired, there is no need to mark the fixing position in advance on the concrete structure to be repaired, and the grid can be firmly fixed to the adhered surface by precisely maintaining the fixing interval. Because only the fixing pins need to be installed on a pre-fixed grid fixing device using a tablet press, etc., workability is excellent and construction speed is fast.

According to the present invention, when constructing a cement mortar composition using a spray method, there is no clogging of the hose or nozzle and there is no waste of material because the rebound amount is small. Compressive strength, bending strength and adhesion strength are all excellent, allowing for solid repair of concrete structures. Or it can be reinforced.

Figure 1 is a diagram showing a textile grid reinforcement.
Figure 2 is a view illustrating the front and side views on which textile grid reinforcement according to the prior art is mounted.
Figure 3 is a photograph illustrating the mortar spray method according to the prior art.
Figure 4 is a construction example of a textile grid reinforcement, a grid fixing device, and a finishing layer using a fixing device for textile grid reinforcement according to the prior art.
Figure 5 is a side view showing a fixing position for installing a grid fixing device on a concrete structure when using a grid fixing device according to the prior art.
Figure 6 is a view showing a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.
Figure 7 is a plan view showing the arrangement of a textile grid, which is a textile reinforcement, and a grid fixing device in a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.
Figure 8 is a diagram specifically showing the cover plate of the grid fixing device in a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.
Figure 9 is a diagram showing a grid fixing device in a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.
Figure 10a is a diagram showing a fixing pin in a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention, and Figure 10b is a diagram illustrating a tablet press for typing the fixing pin.
Figure 11 is an operation flow chart showing a repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.
Figures 12a to 12d are drawings for specifically explaining the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention, respectively.
Figure 13 is a diagram showing the mixing ratio of the cement mortar composition in the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.
Figure 14 is a diagram showing the verification results of the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.
Figure 15 is a diagram showing the manufacturing process of cement mortar in the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.
Figure 16 is a diagram showing the results of a slump flow test in the repair and reinforcement method of a concrete structure according to an embodiment of the present invention.
Figure 17 is a diagram showing the results of a compressive strength test in the repair and reinforcement method of a concrete structure according to an embodiment of the present invention.
Figure 18 is a diagram showing the results of a bending strength test in the repair and reinforcement method of a concrete structure according to an embodiment of the present invention.
Figure 19 is a diagram showing the results of an adhesion strength test in the repair and reinforcement method of a concrete structure according to an embodiment of the present invention.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to “include” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary.

[Concrete structure using textile reinforcement and spray-type cement mortar]

The concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention is repaired and reinforced by the concrete structure repair and reinforcement method using textile reinforcement and spray-type cement mortar, which will be described later. In this case, Figure Repair and reinforcement are performed using the grid fixing device 100 as shown in Figure 6.

Figure 6 is a view showing a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.

Referring to Figure 6, the grid fixing device 100 according to an embodiment of the present invention,

A gap maintenance member 110 in close contact with the adhered surface of the repaired concrete structure 210 to maintain a predetermined gap with the adhered surface;

A cover plate (120) integrated on top of the gap maintenance member (110) and disposed to cover the textile grid (220);

A thickness guide (130) having a predetermined protrusion length to check the construction thickness of the spray cement mortar (230) and fastened to the second through hole (h2) formed on one side of the cover plate (120); and

A fixing pin 140 is typed through the first through hole h1 formed in the center of the body of the grid fixing device 100 and fixes the body of the grid fixing device 100 to the repaired concrete structure 210. ) and consists of.

At this time, the cover plate 120 is manufactured to be slightly larger than the gap between the textile grids 220 so as to cover the textile grid 220, and the gap maintenance material 110 is inserted between the textile grids 220. It is desirable to make it smaller than the spacing of the textile grid 220 as much as possible.

In addition, the thickness guide 130 is made of a plastic material and can guide the construction of the spray cement mortar 230 while observing the construction thickness of the spray cement mortar 230 with the naked eye.

At this time, the protruding length of the thickness guide 130 may be selected in consideration of the final spray thickness of the spray cement mortar 230 applied in multiple stages.

Meanwhile, Figure 7 is a plan view showing the arrangement of a textile grid, which is a textile reinforcement, and a grid fixing device in a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.

The textile grid 220 according to an embodiment of the present invention is made of high-strength fiber such as carbon fiber, and as shown in FIG. 7, a grid fixing device 100 is installed on one side of the textile grid 220 at a constant vertical interval ( It is attached while maintaining the horizontal spacing (a) and (b).

At this time, regardless of the type of the textile grid 220, the vertical spacing (a) and horizontal spacing (b) of the grid fixing device 100 are approximately 100 when the adhered surface of the repaired concrete structure 210 is vertical. It is appropriate that it is within ㎝, and when the adhesion surface of the concrete structure to be repaired 210 is a slab floor or ceiling, it is appropriate that it is within 50 cm.

In addition, when fixing the textile grid 220 according to an embodiment of the present invention to the concrete structure to be repaired 210, there is no need to mark the fixing position in advance on the concrete structure to be repaired 210, and the grid fixing device ( By precisely maintaining the fixing interval of 100, the textile grid 220 can be firmly fixed to the adhered surface of the concrete structure to be repaired 210.

Meanwhile, Figure 8 is a diagram specifically showing the cover plate of the grid fixing device in a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention, and Figure 9 is a diagram showing a textile according to an embodiment of the present invention. A drawing showing a grid fixing device in a concrete structure using reinforcement and spray-type cement mortar,

Figure 9a) shows first and second through holes formed in the cover plate, and Figure 9b) is a side view of the grid fixture.

As shown in FIG. 8, one side of the cover plate 120 is installed so that a thickness guide 130 made of plastic material passes through it. Specifically, the cover plate 120 has a first through hole (h1) so that the fixing pin 140 to be typed on the adhered surface of the concrete structure to be repaired 210 can penetrate later when the textile grid 220 is fixed. A second through hole (h2) through which the thickness guide 130 passes is formed so that the worker can observe the construction thickness of the spray cement mortar 230 during spray construction.

In addition, as shown in Figure 9, the grid fixing device 100 is composed of a gap maintenance member 110, a cover plate 120, a thickness guide 130, and a fixing pin 140, and the cover plate 120 ) is manufactured slightly larger than the spacing of the textile grid 220, and the spacing maintenance member 110 is manufactured smaller than the spacing of the textile grid 220,

Additionally, the fixing pin 140 may be a screw.

Here, the thickness guide 130 serves as a guide to check the final target thickness of the spray cement mortar 230 when the worker sprays the spray cement mortar 230 in multiple stages. Therefore, the protrusion length of the thickness guide 130 can be adjusted by considering the final spray thickness of the spray cement mortar 230.

Meanwhile, Figure 10a is a diagram showing a fixing pin in a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention, and Figure 10b is a diagram illustrating a tablet press for typing the fixing pin.

As shown in FIG. 10A, the fixing pin 140 has a tip 141 sharply formed to fit into the concrete structure to be repaired 210; a body portion 142 whose one side is connected to the distal end 141 and the other side connected to the head 143; and a head 143 formed on the other side of the body 142 to apply a blow.

At this time, the fixing pin 140 is preferably made of a non-corrosive steel material with a strength sufficient to be attached to the concrete structure to be repaired 210.

In addition, the fixing pin 140 may be typed using a tab or tablet press 300, as shown in FIG. 10b, or may be fixed with screws after embedding a so-called knife block.

In the conventional method, workability was low because the grid fixing device and the fixing pin were constructed simultaneously. However, when applying the textile grid 220 according to the embodiment of the present invention, the fixing pin is attached to the pre-fixed grid fixing device 100. Since only (140) needs to be installed using a taper or tablet press (300), workability is excellent and construction speed is fast.

According to an embodiment of the present invention, when fixing a textile grid to a concrete structure to be repaired, there is no need to mark the fixing position in advance on the concrete structure to be repaired, and the grid can be firmly fixed to the adhered surface by precisely maintaining the fixing interval. It has the advantage of excellent workability and fast construction speed because only the fixing pins need to be installed on a pre-fixed grid fixing device using a tablet press.

[Repair and reinforcement method for concrete structures using textile reinforcement and spray-type cement mortar]

Figure 11 is an operation flow chart showing a repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention, and Figures 12a to 12d are respectively a textile reinforcement and spray-type cement mortar according to an embodiment of the present invention. These are drawings to specifically explain the repair and reinforcement method of concrete structures using cement mortar.

Referring to Figures 11 and 12a to 12d, the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention,

First, as shown in Figure 12a, a textile grid 220, which is a textile reinforcement, is placed on the adhered surface of the concrete structure to be repaired 210 (S110).

At this time, before performing step S110, the damaged or deteriorated cross-section of the adhered surface of the repaired concrete structure 210 is removed by grinding or chipping, and then high-pressure water washing is performed to remove the concrete generated by grinding or chipping. It is desirable to remove fine powder.

Specifically, when the adhesion surface of the concrete structure to be repaired 210 is vertical, regardless of the type of the textile grid 220, the horizontal and vertical spacing of the grid fixing device 200 is installed within 100 cm.

In addition, when the adhesion surface of the repaired concrete structure 210 is a slab floor or ceiling, the horizontal and vertical spacing of the grid fixing device 200 is installed within 50 cm regardless of the type of the textile grid 220. In addition, the textile grid 220 is preferably a lattice-shaped textile grid made of high-strength carbon fiber or aramid fiber.

Next, as shown in FIG. 12b, the body of the grid fixture 100 in which the gap maintenance member 110, the cover plate 120, and the thickness guide 130 are combined is attached to the repaired concrete structure 210. Arrange them at predetermined vertical and horizontal intervals on the surface to be adhered (S120).

Next, as shown in FIG. 12C, the grid fixing device 100 is inserted into the fixing pin 140 through the first through hole (h1) formed in the center of the cover plate 120 of the grid fixing device 100. ) is fixed to the repaired concrete structure 210 (S130).

Specifically, the grid fixing device 100,

A gap maintenance member 110 in close contact with the adhered surface of the repaired concrete structure 210 to maintain a predetermined gap with the adhered surface;

A cover plate (120) integrated on top of the gap maintenance member (110) and disposed to cover the textile grid (220);

A thickness guide 130 having a predetermined protrusion length to check the construction thickness of the spray cement mortar 230 and fastened to the second through hole h2 formed on one side of the cover plate 120; and

A fixing pin 140 is typed through the first through hole h1 formed in the center of the body of the grid fixing device 100 and fixes the body of the grid fixing device 100 to the repaired concrete structure 210. ) and consists of.

Here, the cover plate 120 is manufactured to be slightly larger than the gap between the textile grids 220 so as to cover the textile grid 220, and the gap maintenance material 110 is inserted between the textile grids 220. It is desirable to make it smaller than the spacing of the textile grid 220 as much as possible.

In addition, the thickness guide 130 is made of a plastic material and can guide the construction of the spray cement mortar 230 while observing the construction thickness of the spray cement mortar 230 with the naked eye. At this time, the protruding length of the thickness guide 130 may be selected in consideration of the final spray thickness of the spray cement mortar 230 applied in multiple stages.

In addition, the fixing pin 140 includes a tip portion 141 sharply formed to fit into the concrete structure to be repaired 210; a body portion 142 whose one side is connected to the distal end 141 and the other side connected to the head 143; And a head 143 formed on the other side of the body 142 to apply a blow, wherein the fixing pin 140 has a strength that can be attached to the concrete structure to be repaired 210. Can be made of corrosion steel.

Next, as shown in FIG. 12D, spray cement mortar 230 is applied by spraying on the adhered surface of the repaired concrete structure 210 on which the grid fixing device 100 has been installed (S140).

At this time, during the spray method, the final target thickness of the spray cement mortar 230 is formed using the thickness guide 130 formed on the grid fixing device 100.

Here, before performing step S140, it is preferable to spray water on the adhered surface of the concrete structure to be repaired 210 and keep the adhered surface wet for at least 2 hours.

Specifically, the spray-type cement mortar 230 includes 100 parts by weight of binder (B) formed of cement mortar or dry mortar; 110 to 120 parts by weight of fine aggregate, which is sand; 2.5 to 3.2 parts by weight of a high-performance water reducing agent; Liquid admixture, a liquid functional chemical admixture; and 56 to 72 parts by weight of water (W), and can be manufactured by mixing 0.7 to 1.0 parts by weight of reinforcing fiber.

At this time, the spray cement mortar 230 of the spray method is preferably manufactured by setting the ratio (W/B) of water (W) and binder (B) to 0.28 to 0.36.

In addition, the reinforcing fibers are mixed in more than 0.3% of the total volume of the spray cement mortar 230, and the reinforcing fibers are polyvinyl alcohol (PVA) fibers, and are 6 mm short fibers to control drying shrinkage cracks. can be used.

Accordingly, the spray cement mortar 230 can be constructed by spraying while checking the construction thickness of the spray cement mortar 230 through the thickness guide 130 of the grid fixing device 100. For example, the spray cement mortar 230 can be applied to the adhesion surface of the repaired concrete structure 210 in one or multiple stages by spraying.

Ultimately, according to an embodiment of the present invention, when repairing and reinforcing the concrete structure by fixing the textile reinforcement material on the surface of the concrete structure in advance and spraying cement mortar on it using a grid fixing device, the worker applies cement mortar in multiple layers. By using a thickness guide when spraying, the final target thickness can be estimated, and accordingly, the cement mortar for spraying can be precisely constructed.

[Spray-type cement mortar composition]

Figure 13 is a diagram showing the mixing ratio of the cement mortar composition in the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.

In the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention, the cement mortar composition is as shown in FIG. 13. 100 parts by weight of binder (B) formed of cement mortar or dry mortar; 110 to 120 parts by weight of fine aggregate, which is sand; 2.5 to 3.2 parts by weight of a high-performance water reducing agent; Liquid admixture, a liquid functional chemical admixture; and 56 to 72 parts by weight of water (W), and mixed with 0.7 to 1.0 parts by weight of reinforcing fiber. It can be applied using a spray method.

At this time, the spray cement mortar 230 of the spray method is preferably manufactured by setting the ratio (W/B) of water (W) and binder (B) to 0.28 to 0.36.

In addition, the reinforcing fibers are mixed in more than 0.3% of the total volume of the spray cement mortar 230, the reinforcing fibers are PVA fibers, and it is preferable to use 6 mm short fibers to control drying shrinkage cracks.

Meanwhile, Figure 14 is a diagram showing the verification results of the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.

As shown in Figure 14, verification items for repair and reinforcement of concrete structures using spray-type cement mortar include bending strength (MPa), compressive strength (MPa), and adhesion strength (MPa), and the verification standard is 6.0 MPa or more. Bending strength must be satisfied, compressive strength of 20.0 MPa or more must be satisfied, and adhesion strength of 1.0 MPa or more must be satisfied.

As shown in FIGS. 17 to 19 described later, the verification results for the spray-type cement mortar in the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention are 7.4 MPa or more. It was confirmed that the bending strength, compressive strength of more than 55.2 MPa, and adhesive strength of more than 2.1 MPa were satisfied.

Meanwhile, Figure 15 is a diagram showing the manufacturing process of cement mortar in the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention.

Referring to Figure 15, the manufacturing process of cement mortar in the repair and reinforcement method of a concrete structure using textile reinforcement and spray-type cement mortar according to an embodiment of the present invention is: first, cement mortar and fine aggregate are put into a stirrer, and the mixture is stirred at 20 RPM. Dry mixing is performed for 30 seconds at low speed to form a cement mortar mixture (S210).

Next, water (80%), liquid admixture, and high-performance water reducing agent are added to the stirrer and stirred at a medium speed of 30 RPM for 60 seconds (S220).

Next, water (20%) and PVA fiber are mixed in a stirrer and mixed at a high speed of 40 RPM for 120 seconds (S230).

Next, the cement mortar composition for the spray method is discharged from the stirrer (S240).

[Test results of repair and reinforcement method of concrete structures]

Figure 16 is a diagram showing the results of a slump flow test in the repair and reinforcement method of a concrete structure according to an embodiment of the present invention.

The cement mortar 230 for spraying according to an embodiment of the present invention has important fluidity (slump flow test), does not clog the pump hose, has a small amount of rebound when spraying, and can be sprayed to the back of the textile grid 220. The appropriate slump flow at which the cement mortar 230 can be poured is preferably 150 mm to 200 mm.

As shown in Figure 16, the W/C that satisfies the appropriate slump flow was found to be 0.34 and 0.30. At this time, when the slump flow is 150 mm or less, the constructability deteriorates due to overload in transportation from the mixer to the pump to the spray nozzle. Additionally, when the slump flow is 200 mm or more, the rebound amount of the spray cement mortar 230 increases rapidly. and material separation may occur.

In addition, as shown in the above-mentioned FIG. 14, according to KS F 4042 (polymer cement mortar for repairing concrete structures), the required compressive strength and bending strength of the mortar are 20 MPa and 6 MPa or more, respectively.

Meanwhile, Figure 17 is a diagram showing the results of a compressive strength test in the repair and reinforcement method of a concrete structure according to an embodiment of the present invention.

As shown in Figure 17, when mixing cement mortar for spraying (230) according to an embodiment of the present invention, the water/binder ratio (W/C) is set to 0.27, 0.30, and 0.34. As a result of conducting a compressive strength test in accordance with the KS standard test while changing to 5 levels of 0.40 and 0.48, the compressive strength was all satisfied at more than 20MPa.

In addition, PVA short fibers were incorporated into the cement mortar composition for spraying according to an embodiment of the present invention to control drying shrinkage cracks.

Meanwhile, Figure 18 is a diagram showing the results of a bending strength test in the repair and reinforcement method of a concrete structure according to an embodiment of the present invention.

As shown in Figure 18, in the case of bending strength, the mixing ratio of PVA fibers with a length of 6 mm as reinforcing fibers is 0%, 0.1%, 0.2%, and 0.3%. As a result of changing to 6 levels of 0.4% and 0.5%, it was analyzed that the mixing ratio of PVA fibers must be 0.3% or more to secure bending strength due to the crosslinking phenomenon of PVA fibers.

Meanwhile, Figure 19 is a diagram showing the results of an adhesion strength test in the repair and reinforcement method of a concrete structure according to an embodiment of the present invention.

As shown in Figure 19, as a result of evaluating the adhesion strength of the spray cement mortar 230 according to an embodiment of the present invention according to KS F 4042 (polymer cement mortar for repairing concrete structures), the adhesion strength was 1.0 MPa or more. was identified as At this time, it was confirmed that the adhesion strength increased as the mixing ratio of PVA fibers increased.

In addition, in the case of the spray cement mortar 230 according to an embodiment of the present invention, it was confirmed that it satisfied the adhesion strength standard of repair mortar of 1.0 MPa or more regardless of the polymer mixing ratio.

In particular, since PVA fiber has the nature of a hydrophilic fiber, it was confirmed that it has excellent interfacial friction adhesion within the matrix of cement mortar and shows good results in adhesion strength as well as compressive and bending strength of the cement mortar itself.

Ultimately, according to the embodiment of the present invention, when constructing the cement mortar composition by spraying, there is no clogging of the hose or nozzle, there is no waste of material because the rebound amount is small, and the compressive strength, bending strength, and adhesion strength are all excellent, making it suitable for concrete use. Structures can be firmly repaired or reinforced.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as single may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

100: grid fixture
110: Spacer
120: cover plate
130: Thickness guide
140: fixing pin
210: Concrete structure to be repaired
220: Textile grid
230: Cement mortar for spraying
300: Taka or tablet press

Claims (12)

a) placing a textile grid 220, which is a textile reinforcement, on the adhered surface of the repaired concrete structure 210;
b) The body of the grid fixture 100, in which the gap maintenance member 110, the cover plate 120, and the thickness guide 130 are combined, is placed on the surface of the concrete structure to be repaired 210 at a predetermined vertical distance and horizontally. placing at intervals;
c) Inserting the fixing pin 140 through the first through hole (h1) formed in the center of the cover plate 120 of the grid fixing device 100 to attach the body of the grid fixing device 100 to the repaired concrete structure. fixing at 210; and
d) constructing cement mortar for spraying (230) by spraying on the adhered surface of the repaired concrete structure (210) on which installation of the grid fixing device (100) has been completed;
Construct the spray cement mortar 230 by spraying while checking the construction thickness of the spray cement mortar 230 through the thickness guide 130 of the grid fixing device 100, and spray cement using the spray method. Mortar 230 includes 100 parts by weight of binder (B) formed of cement mortar or dry mortar; 110 to 120 parts by weight of fine aggregate, which is sand; 2.5 to 3.2 parts by weight of a high-performance water reducing agent; Liquid admixture, a liquid functional chemical admixture; A repair and reinforcement method for concrete structures using textile reinforcement and spray-type cement mortar, which is manufactured by mixing 56 to 72 parts by weight of water (W) and mixing 0.7 to 1.0 parts by weight of reinforcing fiber. According to paragraph 1,
Before performing step a), the damaged or deteriorated cross-section of the adhered surface of the repaired concrete structure 210 is removed by grinding or chipping, and then high-pressure water washing is performed to remove the concrete fine powder generated by grinding or chipping. removes ,
Before performing step d), spray water on the adhered surface of the repaired concrete structure 210 to keep the adhered surface wet for at least 2 hours,
In step d), the spray cement mortar 230 is sprayed on the adhered surface of the repaired concrete structure 210 in one or multiple stages, using a textile reinforcement material and a spray-type cement mortar. Repair and reinforcement method for concrete structures. According to paragraph 1,
The grid fixing device 100,
A gap maintenance member 110 in close contact with the adhered surface of the repaired concrete structure 210 to maintain a predetermined gap with the adhered surface;
A cover plate (120) integrated on top of the gap maintenance member (110) and disposed to cover the textile grid (220);
A thickness guide 130 having a predetermined protrusion length to check the construction thickness of the spray cement mortar 230 and fastened to the second through hole h2 formed on one side of the cover plate 120; and
A fixing pin 140 is typed through the first through hole h1 formed in the center of the body of the grid fixing device 100 and fixes the body of the grid fixing device 100 to the repaired concrete structure 210. ) A repair and reinforcement method for concrete structures using textile reinforcements containing and spray-type cement mortar. According to paragraph 3,
The cover plate 120 is manufactured to be slightly larger than the gap between the textile grids 220 so as to cover the textile grid 220, and the gap maintenance member 110 is inserted and mounted between the textile grids 220. It is manufactured smaller than the spacing of the textile grid (220),
The thickness guide 130 is made of a plastic material and guides the construction of the spray cement mortar 230 while visually observing the construction thickness of the spray cement mortar 230,
The protrusion length of the thickness guide 130 is selected in consideration of the final spray thickness constructed in multiple stages of the spray cement mortar 230. Repair and reinforcement of concrete structures using textile reinforcement and spray-type cement mortar. Method. delete According to paragraph 1,
The spray-type spray cement mortar 230 is manufactured by setting the ratio (W/B) of water (W) and binder (B) to 0.28 to 0.36, and the spray-type cement mortar and textile reinforcement are manufactured. Repair and reinforcement method for concrete structures used. According to paragraph 1,
The reinforcing fiber is a polyvinyl alcohol (PVA) fiber mixed in more than 0.3% of the total volume of the spray cement mortar 230, and is characterized by using 6 mm short fibers to control drying shrinkage cracks. A repair and reinforcement method for concrete structures using textile reinforcement and spray-type cement mortar. delete delete delete A concrete structure using textile reinforcement constructed using a grid fixture 100 and spray-type cement mortar,
The grid fixing device 100 includes a gap maintenance member 110 in close contact with the adhered surface of the repaired concrete structure 210 to maintain a predetermined gap with the adhered surface; A cover plate 120 integrated on the gap maintenance member 110 and disposed to cover the textile grid 220 disposed on the adhered surface of the concrete structure to be repaired 210; A second penetration formed on one side of the cover plate 120 has a predetermined protrusion length to check the construction thickness of the spray cement mortar 230 applied by spraying on the adhered surface of the repaired concrete structure 210. Thickness guide 130 fastened to the hole (h2); And a fixing pin ( 140); and the spray cement mortar 230 includes 100 parts by weight of binder (B) formed of cement mortar or dry mortar; 110 to 120 parts by weight of fine aggregate, which is sand; 2.5 to 3.2 parts by weight of a high-performance water reducing agent; Liquid admixture, a liquid functional chemical admixture; and 56 to 72 parts by weight of water (W), and mixed with 0.7 to 1.0 parts by weight of reinforcing fiber. The cement mortar is sprayed on the adhered surface of the repaired concrete structure 210 in one or multiple stages. A concrete structure using textile reinforcement and spray-type cement mortar, which is constructed with. According to clause 11,
The cement mortar composition is,
a) Process of forming a cement mortar mixture by putting cement mortar and fine aggregate into a stirrer and performing dry mixing for 30 seconds at a low speed of 20 RPM; b) Adding water (80%), liquid admixture, and high-performance water reducing agent to the stirrer and stirring for 60 seconds at a medium speed of 30 RPM; and water (20%) and PVA fiber are mixed in a stirrer and mixed at a high speed of 40 RPM for 120 seconds,
The spray cement mortar (230) is manufactured by setting the ratio (W/B) of water (W) and binder (B) to 0.28 to 0.36, and the reinforcing fiber is used in the spray cement mortar (230). A concrete structure using textile reinforcement and spray-type cement mortar, which contains PVA fibers that account for more than 0.3% of the total volume and uses 6 mm short fibers to control drying shrinkage cracks.