JP2920287B2 - Reinforcement method for concrete structural members - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for reinforcing a concrete structural member.

[0002]

2. Description of the Related Art Conventional reinforced concrete and prestressed concrete have concrete on the surface, so that the internal steel material may be corroded due to cracks or deterioration of the concrete, which may cause a problem in durability.

[0003] When an excessive load such as seismic force is applied, for example, when a main tensile reinforcing bar or the like yields in the case of a beam, when a bending crack or a shear crack reaches the beam compression portion, the span tension is reduced. The concrete in the compressed part of the beam near the center is rapidly crushed and scattered as fragments, leading to beam destruction. Therefore, it cannot be sufficiently deformed.

[0004] In addition, a large diagonal crack is generated due to the main tensile stress against shearing force and torsion, causing brittle fracture. Therefore, the abdominal reinforcing bar such as a stirrup is designed to be sufficiently arranged so as not to be broken by shearing. In the case where the concrete structural member is a column member, if the load is excessive, the cover concrete is likely to come off.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention
When a lateral pressure (compressive stress) is applied to concrete, which is a brittle material that is strong against compression but weak against tension, the proof stress and deformation capacity are significantly increased. Due to the fact that the proof strength and deformation capacity are several times higher than when compressed in only one axis direction (this is called the confine effect), it is necessary to provide a method for reinforcing concrete structural members using this confine effect It is in.

[0006]

According to the present invention, a chemical prestress is introduced by reinforcing a structural member with a reinforcing material such as a steel plate or FRP, or an existing structure is tightened with a flat belt or a PC steel material. It is another object of the present invention to provide a method for reinforcing a concrete structural member for the purpose of introducing and reinforcing a prestress in a biaxial or triaxial direction.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One of the present invention is to place a concrete block or a concrete block with a steel plate in close contact with the outer periphery of an existing structure, wind it with a reinforcing material such as PC steel or a belt, and further tighten it. A method for reinforcing a concrete structural member, characterized by reinforcing the existing structural member via a concrete block.

Further, two of the present invention are to provide a concrete structural member (a column, a pier or a beam) with a plurality of blocks each having a space formed on a surface corresponding to the structure.
A method for reinforcing a concrete structural member, comprising surrounding the periphery of the block body in a ring shape, winding a reinforcing material around the block body, and injecting an expanding material or expanding mortar into the space.

Next, according to the third aspect of the present invention, when a reinforcing material is wound around an existing concrete structural member (a pillar, a pier or a beam), a space is provided between the existing structure and the reinforcing material. Injecting a cement paste or mortar or concrete using an expanding material into the space and restraining expansion of the expanding material with the reinforcing material to introduce a triaxial or biaxial chemical prestress. This is a method for reinforcing concrete structural members.

Further, in each of the above-mentioned inventions, in the column direction of the existing concrete structure, a PC steel material anchored to a footing is arranged and fixed on concrete in a block or a ring, and bent or bent. You may comprise so that it may resist axial tension force.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. 1. A block member is brought into close contact with a concrete structural member (a column, a pier or a beam) (1) having a rectangular cross section, and When a PC steel material is wound around these blocks and a prestress is introduced or the belt is reinforced with a belt, the belt is wound and tightened. If the structure and the block body cannot be brought into close contact with each other due to the unevenness, the structure is formed by injecting or applying a buffering material such as a sealing material, putty, mortar, resin, or the like to bring the structure into close contact.

An embodiment of the present invention will be described with reference to FIG. 2. Referring to FIG. 2, a space (2a) is formed in a concrete structural member (a column, a pier, or a beam) (1) having a rectangular cross section on a surface corresponding to the structure. A plurality of block bodies (2) are provided, the periphery of which is surrounded in a ring shape, and a reinforcing material (3) is wound around these block bodies, and an expanding material (4) or an expanding mortar (4a) is wound around the space. Is to be injected.

The concrete structural member (1) specifically refers to a column, a pier or a beam, and is shown in FIGS. 1 and 2 as being rectangular, but is not limited thereto. Alternatively, the cross-sectional shape may be circular, elliptical, or polygonal, and the reinforcing material (3) refers to a PC steel material, a belt, a steel plate, or FRP. Furthermore, FRP stands for Five
An abbreviation for r Reinforced Plastic (continuous fiber reinforcing material), which is obtained by hardening carbon fiber, aramid fiber, vinylon fiber, or the like into a sheet or rod shape with an epoxy resin or the like.

Further, as shown in FIG. 7, when the present invention is carried out, in the direction of the column axis of the existing concrete structure (1), the P fixed on the footing (1a) is anchored.
C steel (5) is converted into a block (2) or a reinforcing material (3)
The concrete inside may be arranged and settled to resist bending and axial tension.

Another embodiment of the present invention will be described with reference to FIG. 3. When a reinforcing member (3) is wound around an existing concrete structural member (post, pier, or beam) (1), the existing structure is used. A space (2b) is provided between the object (1) and the reinforcing member (3), and the space (2b) is provided.
b) Inject cement cement or mortar or concrete (4b) using an expanding material and restrain the expansion of the expanding material by the reinforcing material (3) to reduce the chemical prestress in the triaxial or biaxial direction. It is to be introduced.

In the block body (2), a steel plate may be provided in advance on the outer peripheral surface of the block, or a steel plate may be wound around the block and a PC steel material (5) may be provided on the outer peripheral surface. In addition, in the block body, the PC steel material (5) set inside in advance may not adhere to the concrete of the block body.

[0017]

According to the present invention, the existing concrete structural member is tightened mainly by the reinforcing material and the expanding material from the side, so that even if it is damaged or deteriorated, its strength and deformation are remarkable. The ability recovers, and in some cases, exceeds the strength and deformability of the new construction.

According to this method, the structural member has a remarkably increased bending-shear and torsional strength and an increased deformation capacity. Therefore, the structural member has a structure resistant to earthquakes and toughness, that is, large in toughness. This is advantageous because it is larger than that of ordinary concrete.

However, the magnitude of the chemical prestress is determined by the rigidity of the reinforcing member disposed outside the structure, and a part of the strength of the reinforcing member is used for restraining the chemical prestress. Strength is determined by the remaining strength of the reinforcement.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIGS. 2A and 2B are cross-sectional views each showing another embodiment of the present invention.

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a sectional view showing still another embodiment of the present invention.

FIG. 6 is a sectional view showing still another embodiment of the present invention.

FIG. 7 is a side view of the pier shown in FIGS. 1 and 2 showing one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Concrete structural member 2 Block body 2a Space part 3 Reinforcement material 4 Expansive material 4a Cement paste, mortar, concrete using expansive material 5 PC steel material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-279874 (JP, A) JP-A-50-26331 (JP, A) JP-A-52-123524 (JP, A) JP-A 8- 260717 (JP, A) JP 4-17269 (JP, B2) JP 4-17270 (JP, B2) JP 60-44472 (JP, B2) JP 53-43259 (JP, B2) (58) Field surveyed (Int.Cl. ⁶ , DB name) E04G 23/02 E04C 3/26

Claims (7)

(57) [Claims] 1. A plurality of concrete blocks or concrete blocks with a steel plate are closely arranged around an outer periphery of an existing structure, and a prestress is introduced by winding a reinforcing material of PC steel, or a reinforcing material by a belt. And reinforcing the existing structural member with a concrete block through a concrete block. 2. A concrete structural member comprising a plurality of blocks each having a space formed on a surface corresponding to the structure, surrounding the blocks in a ring shape, and wrapping a reinforcing material around these blocks. A method for reinforcing a concrete structural member, comprising injecting an expanding material or expanding mortar into the space. 3. A reinforcing material is provided outside the existing concrete structural member, and a cement paste or mortar or concrete using an expanding material is poured between the existing structure and the reinforcing material to expand the expanding material. A triaxial or biaxial chemical prestress is introduced by constraining the reinforcing member with the reinforcing material. 4. When the existing concrete structure is a column or a pier, a PC steel material anchored (anchored) to the footing is arranged and fixed in an expanded portion in a single-stage or multi-stage block body or ring in the column axis direction. 4. The method for reinforcing a concrete structural member according to claim 1, wherein the method further comprises introducing a prestress to resist bending or axial tensile force. 5. The concrete structure according to claim 1, wherein the concrete structural member is a column, a pier or a beam, and the sectional shape thereof is circular, elliptical, rectangular, or polygonal. 4. The method for reinforcing a concrete structural member according to claim 3. 6. The method for reinforcing a concrete structural member according to claim 1, wherein the reinforcing material is a PC steel material, a belt, a steel plate, and / or an FRP sheet. . 7. The method for reinforcing a concrete structural member according to claim 4, wherein a PC steel material set in advance in the block body is adhered to or not adhered to the concrete block. .