JP2007046263A - Structure and forming method of concrete reinforcing layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely provide reinforcing effect by preventing rupture in a crack position of a reinforcing layer formed by fixing a net-like or mesh-like reinforcing material to a concrete surface by a resin layer. <P>SOLUTION: When forming the reinforcing layer 5 by fixing the reinforcing material 3 to the concrete surface 1 by the transparent resin layer 4, an existing crack 2 and its peripheral concrete surface are covered with an insulating layer 6, and are insulated from the resin layer. A nonadhesive sheet material interposed between the concrete surface and the resin layer in a nonadhesive state and an elastically expandable elastic sheet can be suitably adopted as the insulating layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a structure of a reinforcing layer formed on a concrete surface and a method for forming the reinforcing layer for the purpose of preventing the occurrence of cracks in the surface layer portion of concrete, its progress, and prevention of peeling.

  It can be said that it is almost unavoidable that normal concrete cracks on the surface after a certain number of years after construction. For this reason, concrete structures that require a high degree of soundness and safety over many years, such as concrete as a tunnel lining wall, and peeling that could lead to a serious accident cannot be allowed. For concrete structures, etc., it is necessary to regularly monitor the occurrence and degree of cracks, changes over time, etc., and if cracks are confirmed, repair or reinforcement may be necessary depending on the situation. It is also necessary to do.

  Conventionally, as a measure to repair or reinforce existing concrete that has deteriorated or aged, methods such as striking new concrete on the surface of existing concrete or attaching reinforcing steel plates have been implemented. Since the surface of the existing concrete is concealed, subsequent visual observation is impossible, and it is not applicable when it is necessary to continue monitoring after repair.

  Therefore, in recent years, for example, as shown in Patent Document 1 and Patent Document 2, a method of bonding a reinforcing material made of high-strength fibers to the concrete surface has been proposed. This is based on the fact that a net-like or mesh-like reinforcing material formed of high-strength fibers such as glass fiber, carbon fiber, and aramid fiber is integrally fixed to a concrete surface with a substantially transparent adhesive. . According to this, not only an excellent reinforcing effect on the concrete surface layer portion can be obtained by the tensile strength of the high-strength fibers, but also the concrete surface can be visually observed through the gap even after the reinforcing material is fixed. It is suitable when it is necessary to always observe the occurrence and its development.

In particular, in the construction method shown in Patent Document 2, it has also been proposed to employ a photosensitive resin (photo-curable resin) as an adhesive for fixing the reinforcing material, and according to this, compared to the case of using an ordinary adhesive. Therefore, the curing time can be greatly shortened and construction in a short construction period is possible. Therefore, it is effective as a concrete peeling prevention method for tunnel lining walls, and is expected to be widely used in the future.
JP 2001-355343 A Japanese Patent Laid-Open No. 2003-293692

  By the way, when implementing the above reinforcement | strengthening methods with respect to the concrete which has already cracked, it is assumed that sufficient reinforcement effect is not necessarily acquired.

  That is, as shown in FIG. 3 and FIG. 4 (a), when a relatively large crack 2 has already occurred on the concrete surface 1, it is a net-like shape for the purpose of preventing further development of the crack 2. Alternatively, the reinforcing layer 5 having a structure in which the mesh-like reinforcing material 3 is fixed by the resin layer 4 is conventionally formed on the concrete surface 1, but in that case, as shown in FIG. Further, it is pointed out that the reinforcing layer 5 breaks relatively early and a sufficient reinforcing effect cannot be obtained. The reason is that when a large shearing force in the out-of-plane direction is applied to the concrete surface 1 where the crack 2 is generated, the shearing force is concentrated at the position of the crack 2 to cause a large shear deformation (particularly the crack 2 Deformation that causes both sides of the sheet to shift in the opposite direction) is transmitted to the reinforcing layer 5 as it is, and a large stress concentration occurs there, and the reinforcing layer 5 cannot withstand such stress concentration. It is thought that.

  Therefore, when the reinforcing layer 5 is formed on the concrete surface 1 on which the crack 2 has already occurred, the crack 2 is completely repaired prior to the formation of the reinforcing layer 5 or stress concentration is reduced. It is said that it is necessary to reinforce the reinforcing layer 5 in consideration of this, but in any case, it is inevitable that it takes a lot of labor and cost, and an effective improvement measure is desired. It is.

  In view of the above circumstances, an object of the present invention is to provide an effective and appropriate reinforcing layer structure capable of obtaining an excellent reinforcing effect even when a crack has already occurred on the concrete surface, and a method for forming the same.

  The invention according to claim 1 is a structure of a reinforcing layer formed on a concrete surface in order to prevent cracks in the surface layer portion of the concrete, its progress, and peeling of the concrete piece, and is formed in a net shape or on the concrete surface to be reinforced. The mesh-like reinforcing material is fixed by a transparent resin layer, and between the cracks that have already occurred and the surrounding concrete surface and the resin layer, the crack and the surrounding concrete surface are covered to form a resin. A transparent insulating layer is provided to insulate the layer.

  Invention of Claim 2 is the structure of the concrete reinforcement layer of invention of Claim 1, Comprising: The insulating layer is from the non-adhesive sheet material interposed in the non-adhesive state between the concrete surface and the resin layer. It is characterized by becoming.

  The invention described in claim 3 is the concrete reinforcing layer structure of the invention described in claim 1 or 2, wherein the insulating layer is made of an elastic sheet material that is elastically stretchable.

  The invention according to claim 4 is a method in which a reinforcing layer is formed by adhering a net-like or mesh-like reinforcing material to a concrete surface with a transparent resin layer in order to prevent cracking and progress of the surface layer portion of the concrete, and peeling of the concrete piece. When forming, a transparent insulating layer is formed on the crack surface that has already occurred and the surrounding concrete surface to cover and insulate it from the resin layer. It is characterized by being interposed between concrete and a resin layer.

  According to the present invention, an insulating layer is formed at the crack position and the concrete surface and the resin layer are edged, so that the shear deformation of the concrete surface layer portion generated at the crack position is absorbed by the insulating layer and remains in the reinforcing layer as it is. It is possible to prevent the occurrence of large stress concentration in the reinforcing layer and to prevent early breakage, thereby preventing the reinforcing layer from reinforcing, and the reinforcing effect of the reinforcing layer is reliable and sufficient. Is obtained. In the present invention, an inexpensive material such as a non-adhesive sheet material or an elastic sheet material is used, and it is sufficiently inexpensive and easily insulated by simply interposing it between the concrete surface and the resin layer. A layer can be formed.

  One embodiment of the present invention is shown in FIGS. The reinforcing layer 5 in the present embodiment is basically the same as the conventional one described above, and a net-like or mesh-like reinforcing material 3 made of high-strength fibers is fixed to the concrete surface 1 by a transparent resin layer 4. In addition to this, a transparent insulating layer 6 is formed at the position of the crack 2 that has already occurred on the concrete surface 1, and is formed between the concrete surface 1 and the resin layer 4. It is assumed to be a structure intervening.

  The insulating layer 6 in this embodiment covers the crack 2 and the surrounding concrete surface 1 to insulate the concrete surface 1 around the crack 2 and the resin layer 4 so that they behave integrally. It has the function to prevent.

  As a material of the insulating layer 6 having such a function, for example, a non-adhesive sheet material that maintains a non-adhered state between at least one of the concrete surface 1 and the resin layer 4 or a bonded material is used. However, an elastic sheet material that can be elastically expanded and contracted can be employed. As a specific example, for example, a polyethylene film or a rubber sheet having a thickness of about 0.1 to 0.5 mm is employed, for example, as shown in FIG. It may be arranged in a tape shape and temporarily fixed by being attached to the concrete surface 1 so as to cover the crack 2. Of course, if possible, it is also preferable to employ a sheet material (non-adhesive elastic sheet material or elastically deformable non-adhesive sheet material) having both non-adhesive properties and elasticity as described above.

  In any case, the material of the insulating layer 6 must be transparent enough to allow visual observation of the crack 2, and as long as the thickness of the insulating layer 6 and the formation range thereof have already occurred. In consideration of the size and depth of the crack 2 and the expected amount of shear deformation in the future, it may be set appropriately so as to obtain sufficient insulation performance. It is also conceivable that the insulating layer 6 has a marking function for making the position of the crack 2 conspicuous and clear by coloring the insulating layer 6 so as not to impair the transparency.

  As described above, the reinforcing layer 5 of the present embodiment forms the insulating layer 6 at the position of the crack 2 that has already occurred. When a large deformation occurs at the position of the crack 2 as shown in b), it is suppressed that the deformation is absorbed by the insulating layer 6 and transmitted to the resin layer 4 as it is. As described above, it is possible to prevent a large stress concentration from occurring in the reinforcing layer 5 at the cracked position and prevent the reinforcing layer 5 from breaking early, and an excellent reinforcing effect can be obtained.

  Further, the reinforcing layer 5 of the present embodiment only needs to form the insulating layer 6 at the position of the crack 2 with respect to the conventional general reinforcing layer, so that it is not necessary to completely repair the crack 2 in advance, and the reinforcing layer There is no need to reinforce the 5 itself, and a sufficient reinforcing effect is naturally obtained. Moreover, in order to form the insulating layer 6, it is only necessary to dispose a simple non-adhesive sheet material or elastic sheet material as exemplified above on the concrete surface so as to cover the cracks 2. Since this type of reinforcing layer forming method can be adopted as it is, the labor and cost increase due to the formation of the insulating layer 6 is insignificant, and is extremely rational and effective.

  In the present invention, other configurations are arbitrary as long as the insulating layer 6 is formed at the position of the crack 2, and in particular, known ones can be appropriately employed as the resin layer 4 and the reinforcing material 3. For example, a visible light curable vinyl ester resin is optimal as the resin layer 4, a high-density polyethylene biaxial mesh is optimal as the reinforcing material 3, and a transparent reinforcement made of glass cloth thereon. It is also suitable to laminate sheets. Of course, when the reinforcing layer 5 is formed, appropriate primer treatment, such as primer application, may be performed as necessary.

FIG. 3 is a view showing an embodiment of the present invention and showing a concrete surface on which a reinforcing layer is formed. It is sectional drawing which shows the behavior at the time of a deformation | transformation. It is a figure which shows the concrete surface in which the conventional reinforcement layer was formed. It is sectional drawing which shows the behavior at the time of a deformation | transformation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Concrete surface 2 Crack 3 Reinforcement material 4 Resin layer 5 Reinforcement layer 6 Insulation layer

Claims (4)

It is a structure of a reinforcing layer formed on the concrete surface to prevent cracks in the surface layer of concrete and its progress, and peeling of concrete pieces,
A reinforcing material in the form of a net or mesh is fixed to the surface of the concrete to be reinforced by a transparent resin layer, and between the crack that has already occurred and between the surrounding concrete surface and the resin layer, the crack and its A structure of a concrete reinforcing layer, wherein a transparent insulating layer for covering a surrounding concrete surface and insulating from a resin layer is interposed.   2. The structure of a concrete reinforcing layer according to claim 1, wherein the insulating layer is made of a non-adhesive sheet material interposed in a non-adhesive state between the concrete surface and the resin layer. Construction.   3. The structure of a concrete reinforcing layer according to claim 1, wherein the insulating layer is made of an elastic sheet material that is elastically stretchable. When forming a reinforcing layer by fixing a net-like or mesh-like reinforcing material to the concrete surface with a transparent resin layer in order to prevent cracking of the surface layer of the concrete and its progress, and peeling of the concrete piece,
The insulating layer is cracked and the surrounding concrete and resin layers are formed on the surface of the existing cracks and the surrounding concrete surface by forming a transparent insulating layer to cover and insulate them from the resin layer. A method for forming a concrete reinforcing layer, characterized by being interposed between the two.

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