JP2012072564A - Concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete structure capable of suppressing peeling/scattering of concrete pieces during an impact action, suppressing cracks during the impact action, and demonstrating a high breakage suppressing effect when receiving an impact.SOLUTION: On a surface layer part of a concrete body 2 or between reinforcement materials of double bar arrangement, a reinforcing layer 20 for which a three-dimensional lattice 4 is buried in a cement-based material is provided.

Description

  The present invention relates to a concrete structure.

  Conventionally, as a countermeasure for suppressing destruction of concrete walls (including reinforced concrete walls) that are subjected to impacts such as collision of rigid flying bodies and blast pressure, for example, a method of increasing the wall thickness (thickness of the concrete body) A method of attaching a reinforced steel plate to the front surface (surface that receives impact) or the back surface (surface opposite to the surface that receives impact) is generally performed. However, the above-described method of increasing the wall thickness has a demerit from the viewpoint of effective use of the building space because the area occupied by the frame with respect to the building area increases. In addition, in the above-described method of attaching the reinforcing steel plate, if the reinforcing steel plate is attached to both surfaces of the wall, it is difficult to confirm the soundness of the structure after the impact (the concrete body interposed between the reinforcing steel plates on both sides). There is a demerit that it is.

  Therefore, conventionally, for example, as shown in Patent Document 1 below, a method has been proposed in which a reinforcing sheet is attached to the back surface of a wall or a highly elastic resin is sprayed. According to this method, the thickness of the concrete wall (including the reinforcing sheet and the high-elasticity resin layer) can be reduced as compared with the above-described method of increasing the wall thickness, and the building space can be effectively used. In addition, since the state of the structure can be confirmed from the surface side of the wall, the soundness of the structure can be confirmed after the impact action.

  Conventionally, for example, as shown in Patent Document 2 below, a method of mixing short fibers of steel or synthetic resin into concrete has been proposed. According to this method, it is not necessary to increase the wall thickness, and effective use of the building space can be achieved. In addition, since the state of the structure can be confirmed from the front side or the back side of the wall, the soundness of the structure can be confirmed after the impact action.

JP 2006-257669 A JP 2006-290722 A

However, in the former prior art described above, there is an effect of suppressing the peeling and scattering of the concrete piece on the back surface of the wall at the time of the impact action, but the effect of suppressing the destruction of the concrete body itself is small. There is a risk of cracking in the concrete body.
Moreover, in the latter prior art described above, since the fluidity of ready-mixed concrete decreases and the workability deteriorates when the amount of fibers mixed becomes too large, the amount of fibers mixed is limited. Therefore, there is a case where a sufficient destruction suppressing effect cannot be obtained.

  In the present invention, the above-described conventional problems are considered, and it is possible to suppress the separation and scattering of the concrete pieces at the time of the impact action, and to suppress cracks at the time of the impact action, and when the impact is received. It aims at providing the concrete structure which can exhibit the high destruction inhibitory effect.

  The concrete structure according to the present invention is characterized in that a reinforcing layer in which a three-dimensional lattice is embedded in a cement material is provided in a surface layer portion of the concrete body.

  With such a feature, the stress generated in the concrete body is dispersed by the three-dimensional lattice, so that the stress is prevented from concentrating locally at the time of impact action, and cracks in tensile fracture are dispersed. In addition, since the toughness of the concrete structure is improved by the three-dimensional lattice, the effect of suppressing the destruction is effectively exhibited even for an impact action such as an earthquake.

Further, the concrete structure according to the present invention is a concrete structure in which a double reinforcing bar material is embedded in the concrete body, and between the double reinforcing bar material, inside the cementitious material. A reinforcing layer in which a three-dimensional lattice is embedded may be provided.
Due to such characteristics, the stress generated in the concrete body is dispersed by the three-dimensional lattice, so that internal cracks in the punching shear fracture are dispersed.

In the concrete structure according to the present invention, the elastic coefficient of the material of the three-dimensional lattice is higher than the elastic coefficient of the concrete body, and the strength of the material of the three-dimensional lattice is higher than the strength of the concrete body. preferable.
Thereby, since the resistance force with respect to the tensile stress of a concrete structure improves by a solid lattice, the crack which generate | occur | produces by a stress wave is suppressed.

  According to the concrete structure according to the present invention, it is possible to suppress the separation and scattering of the concrete pieces at the time of the impact action, and to suppress cracks at the time of the impact action, and to exhibit a high destruction suppressing effect when receiving the impact. can do.

It is sectional drawing of the concrete structure for demonstrating the 1st Embodiment of this invention. It is sectional drawing of the concrete structure for demonstrating the 2nd Embodiment of this invention. It is sectional drawing of the concrete structure for demonstrating the modification of this invention. It is sectional drawing of the concrete structure for demonstrating the modification of this invention. It is a perspective view of a three-dimensional lattice for explaining a modification of the present invention. It is a perspective view of a three-dimensional lattice for explaining a modification of the present invention. It is a perspective view of a three-dimensional lattice for explaining a modification of the present invention.

  Hereinafter, first and second embodiments of a concrete structure according to the present invention will be described with reference to the drawings.

[First Embodiment]
First, a first embodiment of a concrete structure according to the present invention will be described with reference to FIG.
A concrete structure 1 shown in FIG. 1 is a reinforced concrete wall subjected to impacts such as collision of a rigid flying body and blast pressure, and has a configuration in which a wall reinforcing bar 3 is embedded inside a concrete body 2. The surface on one side (left side in FIG. 1) of the concrete structure 1 is an impact surface 10 on which a rigid flying body collides or blast pressure acts, and the surface on the other side (right side in FIG. 1). This is the back surface 11 on the opposite side of the impact acting surface 10 described above.

  As shown in FIG. 1, the wall reinforcing bar 3 has a configuration in which main bars and distribution bars made of deformed steel bars are vertically and horizontally assembled in a lattice pattern, and the main bars and distribution bars assembled in this lattice form are doubled. It is a double bar arrangement. The wall rebar 3 is disposed at a position where a predetermined cover thickness is secured.

  Reinforcing layers 20 and 20 in which the three-dimensional lattice 4 is embedded in the cement-based material are respectively provided on the surface layer portions on both sides of the concrete body 2. More specifically, the three-dimensional lattice 4 is embedded in the cover portions 21 and 21 on both sides of the concrete body 2, and the cover portions 21 and 21 are the reinforcing layers 20 and 20.

  The three-dimensional lattice 4 described above is three-dimensionally formed by corrugating or irregularly bending or bending a wire made of steel (for example, general steel or stainless steel) or a synthetic resin (for example, polypropylene). It is a three-dimensional mesh mat, and the thickness dimension of the three-dimensional lattice 4 is at least equal to or less than the cover thickness of the concrete body 2 (the thickness of the cover portion 21). Further, the elastic coefficient of the material of the three-dimensional lattice 4 is larger than the elastic coefficient of the concrete body 2, and the strength of the material of the three-dimensional lattice 4 is larger than the strength of the concrete body 2. The space surrounded by the wire rods (sides) of the three-dimensional lattice 4 is formed into a polyhedron shape such as a tetrahedron or a hexahedron, or a non-uniform shape. Also, the lattice spacing (interval between the wires) of the three-dimensional lattice 4 is such that when the concrete body 2 is placed in concrete, the ready-mixed concrete easily flows into the three-dimensional lattice 4 and fills the entire interior of the three-dimensional lattice 4 with no gaps. It is the magnitude | size to which it is formed, and is formed by the lattice space | interval larger than the largest dimension of the aggregate of the concrete body 2 at least. In addition, when the thickness of the three-dimensional lattice 4 is thin, the lattice interval of the three-dimensional lattice 4 may be smaller than the maximum dimension of the above-described aggregate.

  Next, the construction method of the concrete structure 1 which consists of an above-described structure is demonstrated.

  First, the reinforcing bar arrangement process for assembling the wall reinforcing bar 3 is performed. More specifically, the main reinforcing bars and the reinforcing bars are assembled in a vertical and horizontal grid pattern at predetermined positions to form the double reinforcing wall reinforcement 3.

  Next, a mold erection process for assembling a mold (not shown) for forming the concrete body 2 is performed. If it demonstrates in detail, the formwork which is not shown in figure will be built in the predetermined position of the both sides of the above-mentioned wall reinforcement 3, respectively. At this time, the three-dimensional lattice 4 is installed on the formwork surface of a formwork (not shown). In addition, the method which does not install the three-dimensional lattice 4 on a formwork surface may be sufficient, for example, after installing the three-dimensional lattice 4 on the both sides of the wall reinforcing bar 3, you may build in the formwork which is not shown in figure.

  Next, a concrete placing process for placing ready-mixed concrete in the above-described mold is performed. More specifically, ready-mixed concrete is poured between the double reinforcing wall rebars 3. At this time, a part of the ready-mixed concrete placed in the mold flows into the inside of the three-dimensional lattice 4, and the inside of the three-dimensional lattice 4 is uniformly filled with the ready-mixed concrete.

Then, after hardening of the concrete body 2, the above-mentioned formwork is demolded.
As described above, the wall rebar 3 is embedded inside the concrete body 2, the three-dimensional lattice 4 is embedded in the cover portions 21 and 21 on both sides of the concrete body 2, and the reinforcing layers 20 and 20 are provided on the surface portions on both sides. A concrete structure 1 is formed.

  According to the concrete structure 1 described above, since the stress generated in the concrete body 2 is dispersed by the three-dimensional lattice 4, it is suppressed that the stress concentrates locally at the time of impact action, and cracks in tensile fracture are dispersed. . Further, since the elastic coefficient of the material of the three-dimensional lattice 4 is larger than the elastic coefficient of the concrete body 2 and the strength of the material of the three-dimensional lattice 4 is larger than the strength of the concrete body 2, Since resistance to tensile stress is improved, cracks caused by stress waves are suppressed. Therefore, it is possible to suppress the peeling and scattering of the concrete pieces on the impact surface 10 and the back surface 11 during the impact operation, and it is possible to suppress cracks during the impact operation. Furthermore, since the toughness of the concrete structure 1 is improved by the three-dimensional lattice 4, the destruction suppressing effect is effectively exhibited even for an impact action such as an earthquake. Thus, a high destruction suppressing effect can be exhibited when subjected to an impact.

  Moreover, even if the elastic coefficient and strength of the material (wire) of the three-dimensional lattice 4 are lower than the elastic coefficient and strength of the concrete body 2, the effect of dispersing the cracks can be expected, but it is desirable. Thereby, the effect which suppresses an above-described crack can fully be show | played.

[Second Embodiment]
Next, a second embodiment of the concrete structure according to the present invention will be described with reference to FIG.
In addition, about the structure similar to 1st Embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  A concrete structure 101 shown in FIG. 2 is a reinforced concrete wall, and a double reinforcing wall rebar 3 in which lattice reinforcing bars 30 and 31 are double-laid is embedded inside the concrete body 2. Consists of configuration. In the central portion of the concrete body 2 in the thickness direction, that is, the portion between the double reinforcing bars 30 and 31, a reinforcing layer 20 in which a three-dimensional lattice 4 is embedded in a cement-based material is provided. .

  Next, the construction method of the concrete structure 101 which consists of an above-described structure is demonstrated.

  First, the reinforcing bar arrangement process for assembling the wall reinforcing bar 3 is performed. More specifically, the wall reinforcing bars 3 are formed by assembling the main bars and the distribution bars in a vertical and horizontal lattice shape at predetermined positions. At this time, the three-dimensional lattice 4 is installed between the reinforcing bars 30 and 31 having double reinforcement.

  Next, a mold erection process for assembling a mold (not shown) for forming the concrete body 2 is performed. If it demonstrates in detail, the formwork which is not shown in figure will be built in the predetermined position of the both sides of the above-mentioned wall reinforcement 3, respectively.

  Next, a concrete placing process for placing ready-mixed concrete in the above-described mold is performed. If it explains in detail, fresh concrete will be poured between the reinforcing bar materials 30 and 31 of double reinforcement. At this time, a part of the ready-mixed concrete placed in the mold flows into the inside of the three-dimensional lattice 4, and the inside of the three-dimensional lattice 4 is uniformly filled with the ready-mixed concrete.

Then, after hardening of the concrete body 2, the above-mentioned formwork is demolded.
As described above, the wall reinforcing bar 3 is embedded inside the concrete body 2 and the three-dimensional lattice 4 is embedded between the reinforcing bars 30 and 31 of the double reinforcement, and the reinforcing layer is provided in the central portion in the thickness direction of the concrete body 2. A concrete structure 101 provided with 20 is formed.

  According to the concrete structure 101 described above, since the stress generated in the concrete body 2 is dispersed by the three-dimensional lattice 4, cracks inside the concrete body 2 due to the punching shear failure are dispersed. Since the resistance force against the punching shear stress of the structure 1 is improved, cracks inside the concrete body 2 caused by stress waves are suppressed. Thereby, the destruction inhibitory effect inside the concrete body 2 can be exhibited.

As mentioned above, although embodiment of the concrete structure which concerns on this invention was described, this invention is not limited to above-described embodiment, In the range which does not deviate from the meaning, it can change suitably.
For example, as shown in FIG. 3, a concrete structure 201 in which a fiber sheet 5 is attached to the back surface of the concrete body 2 or a highly elastic resin 6 is sprayed may be used.

In the first embodiment described above, the three-dimensional lattice 4 is embedded in the surface portions (cover portions 21 and 21) on both sides of the concrete body 2 to form the reinforcing layers 20 and 20. The reinforcing layer may be formed only on the surface portion on either the impact acting surface 10 side or the back surface 11 side.
Further, according to the present invention, a reinforcing layer is formed on at least one of the surface portions on both sides of the concrete body 2 and inside the concrete body 2 (between the double reinforcing bar members 30, 31). It may be a configuration.

  In the first embodiment described above, the reinforcing layers 20 and 20 are formed on the surface portion of the concrete body 2 by installing the three-dimensional lattice 4 inside the mold (not shown) during the concrete placing process. However, in the present invention, as shown in FIG. 4, a mortar board 6 (cement-based material) in which a three-dimensional lattice 4 is embedded as a reinforcing bar is manufactured, and this mortar board 6 is built as a formwork. The concrete structure 301 in which the cast-in-place concrete part 321 and the mortar board 6 are integrated by placing ready-mixed concrete inside the mortar board 6 may be used. Thereby, the above-mentioned mortar board 6 used as a mold becomes the reinforcing layer 320, and the reinforcing layer 320 is formed on the surface portion of the concrete body 302. In this case, as shown in FIG. 4, the bonding strength between the in-situ concrete portion 321 and the mortar plate 6 can be improved by protruding a cotter 60 on the inner surface of the mortar plate 6.

In the above-described embodiment, as the three-dimensional lattice 4, a three-dimensional net-like mat formed three-dimensionally by curving or irregularly bending or bending a wire made of steel or synthetic resin is used. However, the present invention can also use a three-dimensional lattice having another configuration.
For example, as shown in FIGS. 5A and 5B, truss-shaped three-dimensional lattices 404 and 504 assembled so that a plurality of bar members 440 and 540 may be a collection of triangles may be used. . Moreover, as shown to Fig.6 (a) and FIG.6 (b), the solid structure 604,704 of the structure which arranged the some lattice member 643,743 in parallel may be sufficient. The lattice members 643, 743 are straight rod-like upper chord members 640, 740 and lower chord members 641, 741, and a plurality of diagonal members 642, 742 interposed between the upper chord members 640, 740 and the lower chord members 641, 741. And a lattice beam-shaped member. 6B includes a corrugated bar 744 that intersects the lattice member 743 and is bent into a corrugation so as to straddle each lattice member 743.
Furthermore, as shown in FIG. 7, a three-dimensional lattice 804 made of a spiral material 840 having a configuration in which a bar is wound in a coil shape may be used.

  In the above-described embodiment, a reinforced concrete wall is described as the concrete structure 1, but the present invention may be a structure other than a wall, such as a column, a beam, or a slab. There may be. Furthermore, the present invention is not limited to a concrete structure made of reinforced concrete, but may be a structure made only of concrete, or other concrete systems such as steel concrete, reinforced steel concrete, steel pipe concrete, etc. It may be a structural body.

In the concrete structure according to the present invention, the elastic coefficient and strength of the three-dimensional lattice material (wire) may be lower than the elastic coefficient and strength of the concrete body. Even in this case, the above-described crack dispersion effect can be expected.
In addition, in the range which does not deviate from the main point of this invention, it is possible to replace suitably the component in above-mentioned embodiment with a well-known component, and you may combine the above-mentioned modification suitably.

1,101,201,301 Concrete structure 2,302 Concrete body 30,31 Reinforcement material 4,404,504,604,704,804 Three-dimensional lattice 20,320 Reinforcement layer

Claims (2)

  A concrete structure characterized in that a reinforcing layer in which a three-dimensional lattice is embedded in a cement material is provided on a surface layer portion of the concrete body. A concrete structure in which a double reinforcing bar material is embedded inside the concrete body,
A concrete structure characterized in that a reinforcing layer in which a three-dimensional lattice is embedded in a cement-based material is provided between the double reinforcing bars.

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