JP7129745B2 - Peeling prevention structure and its construction method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an anti-peeling structure using an anti-peeling sheet that prevents flakes peeled from a structure such as a concrete structure from falling, and a construction method thereof.

Conventionally, as a peeling prevention sheet for preventing the falling of flakes peeled off from the surface of a concrete structure that has deteriorated over time, a synthetic resin sheet on which a shape retainer is superimposed in Patent Document 1, a net-like mesh sheet in Patent Document 2, and a Patent Document A net-like mesh sheet in which 3 FRP grids are superimposed (see FIG. 7, paragraphs [0045] to [0049] of Patent Document 3) is known.

These synthetic resin sheets and mesh sheets are soft and easy to change shape when used alone. It is difficult to handle during installation work. Such inconvenience in handling at the time of construction can be solved to some extent by providing the shape retainer of Patent Document 1 or the FRP grid of Patent Document 3 over the sheet.

JP 2015-129406 A JP-A-2001-355343 Japanese Patent No. 2006-9266

By the way, when constructing a spalling prevention structure with a net-like mesh sheet, the mesh sheet of Patent Document 3 is used in which FRP lattices are provided so that square openings of sizes corresponding to washers and anchor bolts are arranged vertically and horizontally. This makes it easier to handle during installation, but makes it difficult to conform to the mounting surface. In other words, the mesh sheet in which the FRP lattices are superimposed has good shape retention due to the high rigidity of the FRP lattices that form the square opening, but the excessively high rigidity and shape retention may cause unevenness and curved portions. It becomes difficult to follow a certain mounting surface. Therefore, there is a demand for a peeling-preventing sheet that can conform to a mounting surface having irregularities and curved portions and at the same time has good shape retention.

The present invention has been proposed in view of the above problems, and is capable of exhibiting excellent conformability to mounting surfaces with unevenness and curved portions of tunnels, having good shape retention, and being easy to handle during construction. An object of the present invention is to provide a peel-preventing structure using a peel-preventing sheet that can be simplified, and a construction method thereof.

The spalling prevention structure of the present invention includes a net-like mesh sheet and a grid-like shape retainer superimposed on one surface of the mesh sheet and fixed to the mesh sheet. The mutual interval is formed to be larger than the mutual interval of the vertical bars of the shape retaining material, and the rectangular openings surrounded by the horizontal bars and the vertical bars of the shape retaining material are arranged vertically and horizontally , A peeling-preventing sheet is used in which the ratio of the spacing between the bars to the spacing between the vertical bars is in the range of 5:1 to 2:1, and the mesh sheet of the peeling-preventing sheet is a concrete structure. With the lining concrete surface of the tunnel or the surface of the primer layer formed on the lining concrete surface as the mounting surface, it is arranged on the mounting surface side and laid so as to substantially follow the mounting surface, and is cast into the tunnel. A plate is pressed toward the mounting surface by a nut screwed to the anchor, and the plate presses the shape-retaining material toward the mounting surface to attach the peeling prevention sheet, and the shape-retaining material The peeling prevention sheet is arranged with the vertical direction in which the horizontal bars of the shape-retaining material are arranged in the circumferential direction of the tunnel, and the horizontal direction in which the vertical bars of the shape-retaining material are arranged in the axial direction of the tunnel .
According to this, the shape retainer in which the rectangular openings are arranged lengthwise and crosswise to be superimposed on the mesh sheet can provide an appropriate shape retainability. In addition, the interval between the horizontal bars of the shape-retaining material is formed larger than the interval between the vertical bars of the shape-retaining material, and the rectangular openings are arranged vertically and horizontally, so that the peeling prevention sheet can be easily bent and deformed in the horizontal direction. The anti-peeling sheet can be deformed to conform to irregularities and curved portions. That is, it is possible to obtain a peeling prevention sheet that can exhibit excellent conformability to a mounting surface having unevenness and curved portions, has good shape retention, and can be easily handled during construction. can. Also, the peel-off prevention sheet can be easily attached to the mounting surface by pressing the shape-retaining material with a plate. In many cases, the lining concrete surface of the tunnel has curved parts, dented parts, and protruding parts in the direction of excavation. Therefore, by laying the spalling prevention sheet with the horizontal direction aligned with the tunnel axis direction, it can easily follow the curved, dented, or protruding parts that exist on the lining concrete surface in the excavation direction. be able to. In addition, in the vertical direction in which the horizontal bars of the shape-retaining material are arranged, the peel-off prevention sheet exerts an appropriate degree of rigidity such that it bends along the circumferential direction of the tunnel, so that handling can be facilitated.

In the peeling-preventing structure of the present invention, stepped portions are formed at both ends of the plate in the width direction so as to float on the side opposite to the peeling-preventing sheet, and the distance between the stepped portions at both ends is the distance between the vertical bars of the shape-retaining material. It is characterized in that the peeling prevention sheet is attached by being set corresponding to the interval, and the vertical bars of the shape retaining member are pressed against the attachment surface side by the stepped portions at both ends of the plate.
According to this, the vertical bars of the shape retainer can be pressed toward the mounting surface by the stepped portions at both ends, and the peeling prevention sheet can be more easily mounted on the mounting surface. In addition, since the stepped portions at both ends press the vertical bars of the shape-retaining material, it is easy to move the plate and the stepped portion in the longitudinal direction of the rectangular opening to attach the anchor. It is possible to flexibly adapt to the change and adjustment of the placement location.

The method for constructing the anti-peeling structure of the present invention is a method for constructing the anti-peeling structure of the present invention, wherein a primer layer is formed on the lining concrete surface of a tunnel, which is a concrete structure, and the anti-peeling sheet is arranged. , a first step of forming perforations in the lining concrete of the tunnel so as to penetrate the mesh sheet and the primer layer of the spalling prevention sheet; a second step of inserting the anchor screwed into the hole and driving the anchor into the lining concrete ; It is characterized by comprising a third step of pressing to.
According to this, even the primer layer can prevent the construction surface of the concrete structure from coming off. In addition, by pressing the shape-retaining material of the peeling prevention sheet against the mounting surface side with a plate, the mesh sheet can be adhered to the primer layer, and peeling can be reliably prevented. A reinforcing effect can also be obtained by pressing the shape member toward the mounting surface side.

By using the spalling prevention structure of the present invention, it is possible to exhibit excellent conformability to the installation surface with unevenness and curved parts of the tunnel, and since it has good shape retention, it is easy to handle during construction. can be

Planar explanatory drawing of the peeling prevention sheet of embodiment by this invention. FIG. 4 is a partial front view of a state in which a plate, anchors, and nuts are arranged on the peeling prevention sheet of the embodiment; FIG. 4 is a partial perspective view of a state in which a plate, anchors, and nuts are arranged on the peeling prevention sheet of the embodiment; (a) is a front view of an anchor used for attaching the peeling prevention sheet of the embodiment, (b) is a longitudinal sectional view thereof, and (c) is a longitudinal sectional view of the expanded state. (a) is a side view of a nut used for attaching the peeling prevention sheet of the embodiment, and (b) is a longitudinal sectional view thereof. (a) is a side view of a plate used for attaching the peeling prevention sheet of the embodiment, and (b) is a front view thereof. (a) to (c) are cross-sectional explanatory views for explaining construction examples of a peeling prevention structure on which the peeling prevention sheet of the embodiment is laid. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective explanatory view of a peeling prevention structure of a first example in which a peeling prevention sheet of an embodiment is laid; FIG. 4 is a perspective explanatory view of a second example of the peeling prevention structure in which the peeling prevention sheet of the embodiment is laid.

[Anti-peeling sheet, anti-peeling structure and construction method thereof according to the embodiment]
As shown in FIGS. 1 to 3, the peeling-preventing sheet 1 of the embodiment according to the present invention includes a mesh sheet 2 and a grid-like sheet which is superimposed on one surface of the mesh sheet 2 and fixed to the mesh sheet 2. shape retention material 3.

The mesh sheet 2 is composed of a base fabric 21 in which the base threads are arranged in a mesh-like manner, for example, the base threads are arranged vertically and horizontally as warp threads and weft threads, and a coating material 22 that covers the surface of the base fabric (see FIG. 7). ). The mesh sheet 2 may be configured such that openings are provided between adjacent base yarns by covering the outer periphery of each base yarn with the covering material 22, or one side or both sides of the entire base fabric 21 may be covered with the covering material 22. By covering the surface in a planar shape, it may be configured such that there is no opening between the adjacent base yarns and the covering material 22 is closed. The mesh sheet 2 in the example of FIG. 7 has a covering material 22 covering one side of the entire base fabric 21 opposite to the applied side.

As for the material of the mesh sheet 2 and its shape such as knitting method and weaving method, it is possible to use an appropriate material and shape within the applicable range. For example, the base yarn of the base fabric 21 is a high-strength vinylon fiber, and the vinylon fiber is knitted by weft-inserted Raschel knitting. The mesh sheet 2 coated so as to surround the covering material 22, or the base yarn of the base fabric 21 is woven by plain weave or the like with polyester fiber, and the entire base fabric 21 is made of a film-like synthetic resin such as a polyvinyl chloride resin film. It is preferable to use a mesh sheet 2 or the like fixed to one side or both sides of the. Moreover, it is preferable that the length of the maximum opening of the mesh sheet 2 is smaller than the interval between the vertical bars 32 of the shape retainer 3 to be described later, from the viewpoint of prevention of peeling.

In the shape retainer 3, horizontal beams 31 and vertical beams 32 are arranged vertically and horizontally. Rectangular openings 33 surrounded by 32 are arranged vertically and horizontally. The distance between the horizontal beams 31 and 31 and the distance between the vertical beams 32 and 32 can be appropriately set within the scope of the present invention. The spacing ratio between 32 and 32 is preferably in the range of 5:1 to 2:1. In the illustrated example, the interval between the horizontal beams 31 and 31 is 163 mm, and the interval between the vertical beams 32 and 32 is 55 mm. The ratio is approximately 3:1.

The cross-sectional shape of the horizontal beams 31 and the vertical beams 32 of the shape retainer 3 is appropriate within the scope of the present invention. Good. Further, as the material of the shape retainer 3, it is possible to use an appropriate material within an applicable range, and it is preferable to use FRP, for example. The material of the shape retainer 3 in the illustrated example is FRP in which glass fiber is impregnated with thermosetting synthetic resin having alkali resistance. The peeling prevention sheet 1 of the embodiment according to the present invention maintains flexibility with the mesh sheet 2 and rigidity with the shape retention material 3. Flexibility can be selected.

In the anti-peeling structure in which the anti-peeling sheet 1 of the present embodiment is laid, the anti-peeling sheet 1 is attached to the mounting surface using anchors 4, nuts 5, and plates 6, for example. The anchor 4 of this example is a core-rod-driven anchor, and as shown in FIG. A plurality of slits 411 are cut in the anchor body 41 in the axial direction from the distal end thereof, and an expansion piece 412 divided by the slits 411 spaced apart in the circumferential direction is provided. A stepped portion 413 is formed inside the expansion piece 412 , and the expansion piece 412 is expanded by driving the core rod 42 into the stepped portion 413 and inserting the bullet-shaped tip portion 421 into the stepped portion 413 . A male thread 414 is formed on the outer peripheral surface of the rear portion of the anchor body 41 .

The nut 5 of this example is a locking nut with a seat, as shown in FIG. A plate spring 53 is fitted to the nut 5 on the opposite side of the seat portion 52 of the female screw hole 51, and two plate springs 53 are fitted in the illustrated example. The female threaded hole 51 is formed with a size and pitch that can be screwed onto the male thread 414 of the anchor body 41 , and the nut 5 is positioned behind the plate 6 on the male thread 414 of the anchor body 41 to which the plate 6 is externally inserted. screwed together.

The plate 6 of this example is made of stainless steel or the like, and as shown in FIG. On both sides of the base portion 61 in the width direction, stepped portions 63 are formed by being bent in a substantially V-shape. A portion 63 is formed. The floating height H of the stepped portion 63 from the base portion 61 is a height substantially corresponding to the thickness of the vertical crosspiece 32 of the shape retainer 3. It is formed with a height of 5 mm or the like. Also, the interval between the stepped portions 63 on both ends of the plate 6 is set to correspond to the interval between the vertical bars 32 of the shape retainer 3 .

When constructing the anti-peeling structure for laying the anti-peeling sheet 1, for example, as shown in FIG. The primer layer 13 corresponding to the base layer is formed by applying a primer or the like, such as urethane resin, epoxy resin, or acrylic resin, which is impregnated into the cracks of the construction surface 12 and solidifies. When the primer layer 13 is formed, the surface of the primer layer 13 serves as the attachment surface of the anti-peeling sheet 1 .

After that, the mesh sheet 2 is arranged on the surface side of the primer layer 13 corresponding to the mounting surface, the peeling prevention sheet 1 is arranged, and the drill 14 is made to penetrate the mesh sheet 2 and the primer layer 13 of the peeling prevention sheet 1. , drill holes 15 are formed in the concrete structure 11 at predetermined positions on the construction surface 12 (see FIG. 7(a)). At this time, since the position where the perforation 15 is formed is the position where the anchor 4 that supports the plate 6 is driven, the stepped portions 63 on both sides of the plate 6 correspond to the adjacent vertical bars 32 . The drill 14 may be passed through the insertion hole 62 of the arranged plate 6 to form the perforation 15 .

Next, the anchor 4 with the plate 6 inserted in advance and the nut 5 screwed to the position on the rear side of the plate 6 substantially corresponding to the anchor embedding length + peeling prevention sheet thickness + plate thickness is inserted into the hole 15 . , the core rod 42 is driven by the hammer 16 to expand the expansion piece 412, and the anchor 4 is driven into the concrete structure 11 (see FIGS. 7B and 7C). The anti-peeling sheet 1 is temporarily fixed to the construction surface 12 by driving the anchors 4 through the anti-peeling sheet 1 .

After that, the nut 5 that is screwed onto the male thread 414 of the anchor 4 is screwed in, and the plate 6 is pressed against the mounting surface side or the construction surface 12 side by the nut 5, and the stepped portions 63, 63 at both ends of the plate 6 are pressed. The adjacent vertical beams 32 of the shape retainer 3 are pressed toward the mounting surface side or the construction surface 12 side. As a result, the anti-peeling sheet 1 or its mesh sheet 2 is attached so as to be pressed against the outer surface of the primer layer 13 through the plate 6, thereby constructing an anti-peeling structure (see FIG. 7(c)). In the constructed peeling prevention structure, the peeling prevention sheet 1 or its mesh sheet 2 is laid so as to substantially follow the surface of the primer layer 13 corresponding to the mounting surface, and is closely attached to the outer surface of the primer layer 13 without gaps. Even if the surface of 13 has a curved protuberance or the like, the anti-peeling sheet 1 or its mesh sheet 2 is provided so as to be in close contact therewith.

The anti-peeling sheet 1 of the present embodiment or the anti-peeling structure using the same can be well adapted to the construction surface 12 of a concrete structure 11 with large undulations. It is possible to adapt to the construction surface 12 having a large dent 121 on the surface. In this case, the peeling prevention sheet 1 is arranged in the horizontal direction in which the vertical beams 32 of the peeling prevention sheet 1 that is easy to bend are aligned in the construction progress direction D in which the dents 121 appear (the direction in which the number of horizontal beams extending in the direction in which the horizontal beams 31 extend is small). ), and the vertical direction in which the horizontal crosspieces 31 of the peeling prevention sheet 1 are aligned (the direction in which the vertical crosspieces 31 extend and the number of crosspieces extending in the direction in which the vertical crosspieces 31 extend) is aligned with the direction perpendicular to the traveling direction D, It is preferable to construct a spalling prevention structure.

In addition, as shown in FIG. 9, the construction surface 12 is the lining concrete surface of the tunnel T, and when the peeling prevention sheet 1 is laid on this lining concrete surface to construct the peeling prevention structure, the horizontal beam of the peeling prevention sheet 1 The vertical direction in which the vertical bars 31 are arranged (the direction in which the number of bars extending in the direction in which the vertical bars 31 extend) is aligned with the tunnel circumferential direction C, and the horizontal direction in which the vertical bars 32 that are easy to bend of the peeling prevention sheet 1 are arranged (the number of horizontal bars 31). It is preferable to construct the anti-peeling structure by laying the anti-peeling sheet 1 so that the direction in which the number of crosspieces extending in the extending direction is small) is aligned with the axial direction X of the tunnel. As a result, the peeling-off prevention sheet 1 can be bent in the horizontal direction where the easily bendable vertical bars 32 are arranged to substantially follow the undulations appearing on the construction surface 12 in the axial direction X of the tunnel, and can be bent to the extent that it follows the inner peripheral surface of the tunnel. The peeling prevention sheet 1 can be bent in the vertical direction in which the horizontal beams 31 that can be attached are aligned, and can be substantially along the surface of the primer layer 13 corresponding to the construction surface 12 or the mounting surface of the inner peripheral surface of the tunnel.

According to the peeling-preventing sheet 1 of the present embodiment, the shape retainer 3 in which the rectangular openings 33 are arranged vertically and horizontally overlaid on the mesh sheet 2 makes it possible to obtain an appropriate shape retainability. Further, the interval between the horizontal beams 31 of the shape retainer 3 is formed larger than the interval between the vertical beams 32, and the rectangular openings 33 are arranged vertically and horizontally, so that the peeling prevention sheet 1 can be easily bent and deformed in the horizontal direction. The anti-peeling sheet 1 can be deformed to conform to irregularities and curved portions. That is, the anti-peeling sheet can exhibit excellent conformability to the mounting surface or construction surface 12 having irregularities and curved portions, has good shape retention, and can be easily handled during construction. can be 1.

In addition, according to the anti-peeling structure using the anti-peeling sheet 1 of the present embodiment and the construction method thereof, even the primer layer 13 can prevent the construction surface 12 of the concrete structure 11 from coming off. In addition, by pressing the shape-retaining material 3 with the plate 6, the anti-peeling sheet 1 can be easily attached to the construction surface 12 or the surface of the primer layer 13 corresponding to the attachment surface. In addition, the mesh sheet 2 is brought into close contact with the primer layer 13 to ensure the prevention of peeling. , a reinforcing effect can also be obtained.

In addition, due to the configuration in which the vertical beams 32 of the shape retainer 3 are pressed against the construction surface 12 by the stepped portions 63, 63, the peeling prevention sheet 1 can be easily attached to the construction surface 12 or the surface of the primer layer 13 corresponding to the mounting surface. can be attached to Furthermore, it is easy to move and attach the plate 6 and the stepped portions 63 and 63 in the longitudinal direction of the rectangular opening 33, and flexibly adapts to changing and adjusting the placement location of the anchor 4 when attaching the anti-separation sheet 1. can do.

Further, when constructing a spalling prevention structure using the concrete lining surface of the tunnel T as the construction surface 12, the concrete lining surface of the tunnel T often has a curved portion, a recessed portion, or a projecting portion in the excavation direction. However, since the peeling prevention sheet 1 is easily bent and deformed in the horizontal direction in which the vertical bars 32 of the shape retaining material 3 are arranged, by laying the peeling prevention sheet 1 with the horizontal direction aligned with the tunnel axis direction X It can easily follow a curved portion, a dented portion, or a projecting portion existing in the excavation direction on the lining concrete surface. In addition, in the vertical direction in which the horizontal beams 31 of the shape-retaining material 3 are arranged, the peel-off prevention sheet 1 exerts appropriate rigidity to the extent that it bends along the tunnel circumferential direction T, so that handling can be facilitated.

[Scope of invention disclosed in this specification]
In addition to each invention and embodiment listed as an invention, the invention disclosed in this specification is specified by changing these partial contents to other contents disclosed in this specification within the applicable range, Alternatively, what is specified by adding other contents disclosed in this specification to these contents, or what is specified by deleting these partial contents to the extent that partial effects can be obtained and making them a broader concept contain. And the invention disclosed in this specification includes the following contents and modifications

For example, in the peeling prevention structure of the above embodiment, the vertical bars 32 of the shape retaining material 3 of the peeling prevention sheet 1 are pressed against the construction surface 12 by the stepped portions 63 of the plate 6. Any configuration in which a peel-preventing sheet is attached by pressing the shaped material to the construction surface side is included in the peeling-preventing structure of the present invention. Moreover, the anchor, nut, and plate used in the spalling prevention structure of the present invention are appropriate within the scope of the present invention. The anti-peeling structure of the present invention also includes a configuration in which the primer layer is not formed on the construction surface and the anti-peeling sheet is laid on the construction surface of a concrete structure or the like as the mounting surface.

The present invention is installed on various structures such as tunnels, bridges, towers, etc. where flakes may fall, or on parts of various structures where flakes may fall, such as columns, beams, girders, walls, and the bottom surface of slabs. can be used as

DESCRIPTION OF SYMBOLS 1... Peeling prevention sheet 2... Mesh sheet 21... Base fabric 22... Covering material 3... Shape retention material 31... Horizontal bar 32... Vertical bar 33... Opening 4... Anchor 41... Anchor body 411... Slit 412... Expanding piece 413... Step Part 414 Male screw 42 Core rod 421 Tip 5 Nut 51 Female screw hole 52 Seat 53 Plate spring 6 Plate 61 Base 62 Insertion hole 63 Step 11 Concrete structure 12 Construction surface DESCRIPTION OF SYMBOLS 121... Recess 13... Primer layer 14... Drill 15... Drilling 16... Hammer H... Floating height D... Direction of construction T... Tunnel C... Tunnel circumferential direction X... Tunnel axial direction

Claims (3)

A net-like mesh sheet and a grid-like shape retainer superimposed on one surface of the mesh sheet and fixed to the mesh sheet, wherein the mutual intervals between the horizontal bars of the shape retainer are the shape retainer. rectangular openings surrounded by the horizontal beams and the vertical beams of the shape retainer are arranged vertically and horizontally, and the mutual distance between the horizontal beams and the vertical A peeling prevention sheet having a ratio of the mutual spacing of the crosspieces in the range of 5:1 to 2:1 is used,
The mesh sheet of the peeling prevention sheet is arranged on the mounting surface side with the lining concrete surface of the tunnel that is a concrete structure or the surface of the primer layer formed on the lining concrete surface as the mounting surface. A plate is pressed toward the mounting surface by a nut that is laid substantially along the surface and screwed to an anchor that is driven into the tunnel, and the shape retainer is pressed toward the mounting surface by the plate. With the peeling prevention sheet attached,
The peeling prevention sheet is arranged with the vertical direction in which the horizontal bars of the shape-retaining material are arranged in the tunnel circumferential direction, and the horizontal direction in which the vertical bars of the shape-retaining material are arranged in the tunnel axial direction. Peeling prevention structure . Stepped portions are formed at both ends of the plate in the width direction, and the stepped portions rise to the side opposite to the anti-peeling sheet,
The interval between the stepped portions at both ends is set corresponding to the interval between the vertical bars of the shape-retaining material,
2. The anti-peeling structure according to claim 1 , wherein the vertical bars of the shape-retaining material are pressed toward the mounting surface by the stepped portions at both ends of the plate, and the anti-peeling sheet is attached. A method for constructing a peeling prevention structure according to claim 1 or 2 ,
A primer layer is formed on the lining concrete surface of a tunnel, which is a concrete structure, and the peeling prevention sheet is arranged, and the lining concrete of the tunnel is formed so as to penetrate the mesh sheet of the peeling prevention sheet and the primer layer. a first step of forming perforations in
a second step of inserting the anchor, in which the plate is externally inserted and the nut is screwed to the rear side of the plate, into the hole and driving the anchor into the lining concrete ;
A method for constructing a spalling prevention structure, comprising a third step of screwing the nut and pressing the shape retainer toward the mounting surface with the plate.

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