JP5646209B2 - Concrete column reinforcement structure - Google Patents

Description

  The present invention relates to a reinforcing structure for reinforcing an existing concrete column.

Conventionally, in order to improve the earthquake resistance of an existing building structure, a reinforcing structure that newly surrounds the outer periphery of a reinforced concrete column is known.
For example, as shown in FIG. 4, the reinforcing structure described in Patent Document 1 is provided with a surrounding steel plate 2 around the concrete pillar 1 while maintaining a predetermined interval. This enclosure steel plate 2 is a member having a L-shaped cross section in a plane orthogonal to the longitudinal direction, and the corners correspond to the four corners of the concrete column 1 and the adjacent enclosure steel plates 2 are overlapped with each other. Yes.
And the outer periphery of the said surrounding steel plate 2 is bundled by winding the strip | belt-shaped sheet | seat 5. As shown in FIG.

Further, a grout material 3 is injected into the gap between the concrete column 1 and the surrounding steel plate 2, and a plurality of reinforcing bars 4 are provided in the grout material 3 in parallel or substantially parallel to the axial direction of the concrete column 1. ing.
As a result, the bending strength and shear strength of the concrete column could be dramatically improved.

JP 2008-240368 A Japanese Patent No. 3860791

In the reinforcing structure as described above, the reinforcing bars 4 are arranged in the grout material 3 between the concrete column 1 and the surrounding steel plate 2 in order to increase the bending strength and the shear strength.
However, in such a structure, it is necessary to surround the outer periphery of the reinforcing bar 4 with the grout material 3 in order to hold the reinforcing bars 4 arranged in the interval between the concrete column 1 and the surrounding steel plate 2 upright in the axial direction of the concrete column 1. The amount of grout 3 used was increased. Therefore, there is a problem that the thickness of the grout material 3, that is, the interval S1 (see FIG. 4) between the concrete column 1 and the surrounding steel plate 2 becomes large.

Thus, if the thickness of the grout material 3 is increased, the concrete pillar after the seismic reinforcement will be thickened accordingly, and the internal space of the building having such a pillar will be narrowed. . Moreover, if the usage-amount of the grout material 3 increases, material cost will also increase.
An object of the present invention is to provide a concrete column reinforcing structure that suppresses the amount of grout material and keeps the column thickness as small as possible while maintaining sufficient bending strength and shear strength by seismic reinforcement. It is.

A first invention is a reinforcing structure in which a surrounding steel plate is provided at a predetermined interval on the outer periphery of a concrete column having a quadrangular or substantially quadrangular cross section, and a grout material is injected into the interval between the concrete column and the surrounding steel plate. in, along with the cross-sectional shape provided with a reinforcing axial member of the L-shaped at positions corresponding to four corners of the concrete column, and along the reinforcing axis member to the inner peripheral surface of the enclosure steel sheet, the reinforcing shaft The grout material is filled between the inner surface of the directional member and the surface of the concrete column, and the cross-sectional area of the column is increased by the filled grout material .

  The second invention is a flat plate member in which the enclosed steel plate is parallel to each side surface of the concrete column, and an elastic belt-like sheet is wound around the outer periphery of the enclosed steel plate to hold the enclosed steel plate, The enclosure steel plate is slidably brought into contact with the outer peripheral surface of the reinforcing axial member.

According to this invention, the reinforcing axial member having an L-shaped cross section functions in the same manner as a conventional reinforcing bar, and can greatly improve the bending strength and shear strength of a concrete column.
Moreover, a grout for holding the reinforcing axial member along the axial direction of the concrete column by using an L-shaped reinforcing axial member corresponding to the corner of the concrete column instead of the conventional reinforcing bar. The thickness of the material can be reduced.
The reason is that the thickness of the reinforcing axial member having the L-shaped cross section is smaller than the diameter of the round bar as compared to the reinforcing bar of the round bar having the same cross-sectional area, so the amount of the grout material holding the reinforcing axial member This is because it can be reduced as compared with the case where a reinforcing bar is used.
Therefore, the thickness of the grout material provided on the outer periphery of the concrete column can be reduced as compared with the conventional case where the reinforcing bars are arranged in the grout material, and the post-reinforcement column is not so thick. Therefore, the space in the building is not narrowed by seismic reinforcement.

  According to the second invention, since the outer peripheral surface of the reinforcing axial member and the surrounding steel plate are slidably provided, when the concrete pillar is deformed due to the occurrence of an earthquake, the reinforcing member adhered to the grout material The axial member and the surrounding steel plate slide relative to each other. At this time, vibration energy is absorbed by the sliding friction of the sliding surface, and the vibration can be attenuated. That is, according to the second aspect of the invention, not only the bending strength and the shear strength can be maintained while reducing the grout material, but also a vibration damping effect can be obtained.

It is sectional drawing of the reinforcement structure of 1st Embodiment. It is a perspective view of the axial member for reinforcement of a 1st embodiment. It is the elements on larger scale of the reinforcement structure of 2nd Embodiment. It is sectional drawing of the conventional reinforcement structure.

FIG. 1 is a cross-sectional view of a first embodiment in which a reinforcing structure of the present invention is applied to a concrete column 1.
In the first embodiment, rectangular enclosure steel plates 7, 7, 7, 7 are arranged parallel to each other with a predetermined distance from each side surface of the rectangular concrete pillar 1. A reinforcing axial member 6 having an L-shaped cross-section is provided on the side of the concrete column 1 between a pair of matching steel plates 7 and 7.

As shown in FIG. 2, the reinforcing axial member 6 is formed into a L shape by bending a so-called striped steel plate having a large number of ribs 6c on one surface 6a at a right angle with the ribs 6c inside. It is a long member.
The reinforcing axial member 6 is disposed at a position corresponding to each corner of the concrete column 1 and is continuous from the floor slab to the ceiling slab, and the outer surface 6b is provided in contact with the inner peripheral surface of the surrounding steel plate 7. ing.

Further, for example, a belt-like sheet 5 having elasticity such as a prepreg is wound around the outer periphery of the surrounding steel plates 7, 7, 7, 7 to hold the surrounding steel plates 7, 7, 7, 7, A grout material 3 is injected between the concrete pillars 1 and solidified.
However, between the contact surfaces of the surrounding steel plates 7 and 7 and the reinforcing axial member 6, the grout material 3 is prevented from entering and sticking together, and when a predetermined external force is applied, the enclosure The steel plate 7 and the reinforcing axial member 6 are configured to be relatively movable while sliding.

  Thereby, the existing concrete pillar 1 is reinforced by the grout material 3, the reinforcing axial member 6, the steel plate 7, and the belt-like sheet 5 provided on the outer periphery, and becomes a thick pillar. In particular, since the reinforcing axial member 6 is continuous in the vertical direction along the concrete column 1, it functions in the same manner as the reinforcing bar 4 in the conventional reinforcing structure. That is, by providing the reinforcing axial member 6, sufficient bending strength and shear strength can be realized.

In addition, since the reinforcing axial member 6 is formed of a steel plate having an L-shaped cross section, the thickness of the steel plate can be made smaller than the diameter of the reinforcing bar of the round bar.
For example, when the thickness t = 4.5 (mm) and the length L of both pieces L = 100 (mm), the diameter of a reinforcing bar having the same cross-sectional area is about 33.5 (mm).
If the cross-sectional areas are the same, the L-shaped member and the round bar do not necessarily exhibit the same function, but it is certain that the bending strength and the shear strength are increased by increasing the cross-sectional area. Conventionally, in order to increase the bending strength and the shear strength, it is necessary to provide a reinforcing bar having a diameter larger than the thickness t of the reinforcing axial member 6 of the first embodiment in the grout material 3 as a result. The thickness S1 of the material 3 had to be increased.

In other words, in this embodiment, since the reinforcing axial member 6 in which the steel plate is L- shaped is provided in contact with the inner side surface of the surrounding steel plate 7 , the thickness S2 of the grout material 3 (see FIG. 1) is set. It can be made smaller than the conventional thickness S1 (see FIG. 4).
Therefore, the amount of the grout material 3 can be reduced, and the concrete pillar 1 can be kept from becoming thick due to the seismic reinforcement.

  It should be noted that the thickness t and the length L of the reinforcing axial member 6 necessary for obtaining a sufficient reinforcing effect depend on the material of the steel plate and the dimensions of the concrete column 1 to be reinforced, Usually, when reinforcing a concrete pillar 1 having one side of 800 mm, the length of both pieces of the reinforcing axial member 6 formed by bending a striped steel plate having a thickness t = 4.5 mm is set. It has been confirmed that a reinforcing effect equivalent to that of the conventional case using a reinforcing bar 4 having a diameter of about 50 (mm) is obtained using a material with L = 100 to 300 (mm).

  Moreover, in this 1st Embodiment, since the reinforcing axial member 6 is comprised by the striped steel plate which formed the several rib 6c, rigidity can be hold | maintained even if the whole thickness of a steel plate is made thin. Furthermore, since the inner surface 6a on which the rib 6c is formed is directed toward the concrete column 1, the contact area between the grout material 3 filled around the concrete column 1 and the surface 6a is increased. Therefore, sufficient adhesion between the reinforcing axial member 6 and the grout material 3 can be obtained by using only the inner surface 6 a without contacting the grout material 3 on the outer surface 6 b side of the reinforcing axial member 6. Thus, the reinforcing axial member 6 is securely connected to the concrete pillar 1 through the grout material 3.

Furthermore, in the reinforcing structure of the first embodiment, as described above, the inner side surface of the surrounding steel plate 7 and the outer side surface 6b of the reinforcing axial member 6 are slidably provided.
Therefore, when an earthquake occurs and the concrete pillar 1 is deformed, the reinforcing axial member 6 integrated with the concrete pillar 1 moves relative to the surrounding steel plate 7. Thus, sliding friction occurs between the two members that move relative to each other, and vibration can be absorbed by this friction.

That is, the reinforcing structure of the first embodiment also has a vibration control function.
As described above, in the first embodiment, the reinforcing axial member 6 and the surrounding steel plate 7 are slidable with respect to each other, but the contact surface between the reinforcing axial member 6 and the surrounding steel plate 7 is provided. It may be fixed. In that case, although the seismic control function is not exhibited, the object of the present invention can be achieved in which the amount of the grout material 3 is reduced and the thickness thereof is reduced while reinforcing the bending strength and shear strength.

The second embodiment shown in FIG. 3 has the same configuration as that of the first embodiment except that a flexible linear member 8 is provided in the gap between adjacent steel plates 7 and 7.
The linear member 8 is a linear member provided in the axial direction along the corner of the reinforcing axial member 6, and the enclosure steel plate 7 moves relative to the reinforcing axial member 6 when an earthquake occurs. When doing, it is a member which deform | transforms and permits the movement of the surrounding steel plate 7. FIG. Providing such a linear member 8 closes the gap between the surrounding steel plates 7 and 7, so that there is a merit that the position of the surrounding steel plate 7 can be maintained and the belt-like sheet 5 can be easily wound.
Further, in the reinforcing structure of the second embodiment, it is possible to reduce the thickness of the grout material 3 while maintaining the bending strength and the shear strength and to reduce the thickness thereof, and to have a vibration control function. Is the same as in the first embodiment.

DESCRIPTION OF SYMBOLS 1 Concrete pillar 3 Grout material 5 Strip sheet 6 Reinforcing axial member 6a (Inner side) surface 6b (Outer side) surface 6c Rib 7 Enclosure steel plate

Claims (2)

In a reinforcing structure in which a surrounding steel plate is provided at a predetermined interval on the outer periphery of a concrete column having a quadrangular cross section or a substantially quadrangular shape, and a grout material is injected into the interval between the concrete column and the surrounding steel plate, A reinforcing axial member having an L-shaped cross section is provided at positions corresponding to the four corners . The reinforcing axial member is disposed along the inner peripheral surface of the surrounding steel plate, and the inner surface of the reinforcing axial member and the concrete are provided. A concrete column reinforcement structure in which the grout material is filled between the surface of the column and the cross-sectional area of the column is increased by the filled grout material .   The enclosure steel plate is a flat plate member parallel to each side of the concrete column, and an elastic strip is wound around the circumference of the enclosure steel plate to hold the enclosure steel plate, and the reinforcing axial member The reinforcing structure for a concrete column according to claim 1, wherein the surrounding steel plate is slidably brought into contact with an outer peripheral surface of the concrete column.

Images