JP2012202079A - Earthquake-proof slit member and building using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin foam earthquake-proof slit member capable of improving its structural resistance by avoiding a non-structural wall from damaging a structural part even when a quake greater than a design value occurs, and of facilitating mounting work in a concrete form.SOLUTION: An earthquake-proof slit member 6a to be disposed in a clearance (earthquake-proof joint) 5 between a non-structural wall 4 and a structural part (column) 2 of a reinforced-concrete building is formed of a low-expansion-ratio resin foam having a critical compression stress as great as or approximate to the allowable compression stress of a concrete to be used for the building. The earthquake-proof slit member 6a is formed preferably of the low-expansion-ratio resin foam having the critical compression stress of 10-40 N/mm, and more preferably of a polystyrene low-expansion-ratio resin foam having an expansion ratio of five or smaller.

Description

  The present invention relates to an earthquake-resistant slit material and a building in which the earthquake-resistant slit material is arranged at a joint portion between a non-structural wall and a structural portion.

  In a reinforced concrete structure with a ramen structure, structural parts such as columns are designed to be deformed during an earthquake. In order not to prevent the deformation of the structural part, a gap (seismic joint) was provided between the non-structural wall such as the vertical wall, the waist wall and the sleeve wall and the structural part such as the pillar, and both were cut off. It is in a state. Specifically, a gap (seismic joint) that can follow an interlayer deformation angle of 1/100 generated in a building during an earthquake is provided at the joint between the non-structural wall and the structural portion.

  Conventionally, as described in Patent Document 1 or Patent Document 2, by arranging an earthquake-resistant slit material made of a foamed resin material in a gap formed between a non-structural wall and a structural portion, edge cutting is ensured. However, ventilation of joint gaps and leakage of rainwater are blocked, and generally, a high-magnification foamed resin material having a foaming ratio of about 50 to 80 is used for the earthquake-resistant slit material.

JP 2002-13311 A JP 2006-207297 A

  As described above, the foamed resin conventionally used as an earthquake-resistant slit material is a highly flexible foamed resin having a foaming ratio of about 50 to 80 and rich in flexibility. The reason is that it was considered that the earthquake-resistant slit material should be rich in flexibility in order to ensure the interlaminar deformation mobility of the structure portion. However, high-magnification foamed resin is poor in compression resistance, and when a vibration exceeding the design value occurs in the building, the earthquake-resistant slit material buckles, and it is a non-structural wall such as a waist wall, drooping wall, sleeve wall, etc. There is a risk that the corners of the butt will contact the structure and cause brittle fracture. There is also a risk of damaging structural parts such as pillars. Furthermore, at the time of construction, the seismic slit material is installed in the concrete formwork, and concrete is placed so that an earthquake joint with a predetermined width is formed. Since it takes time and effort to attach, and the compression resistance is low, it is necessary to reinforce the surface with an appropriate material in order to ensure the strength to withstand the side pressure when placing concrete.

  The present invention has been made in view of the circumstances as described above, and improves structural strength by avoiding damage to the structural portion of the non-structural wall even when a swing exceeding the design value occurs. A foamed resin earthquake-resistant slit material that can be installed in a mold and can be easily installed, and a reinforced concrete structure in which the earthquake-resistant slit material is arranged at the joint between a non-structural wall and a structural part Is an issue.

  A first aspect of the earthquake-resistant slit material according to the present invention is an earthquake-resistant slit material arranged at a joint portion between a non-structural wall and a structural portion of a reinforced concrete structure, and the earthquake-resistant slit material is used for the building. It is characterized by being made of a foamed resin having a limit compressive stress that is similar to or close to the allowable compressive stress of the concrete to be produced.

The aseismic slit material according to the present invention is an aseismic slit material disposed at a joint between a non-structural wall and a structural part of a reinforced concrete structure, and has a low limit compressive stress in the range of 10 to 40 N / mm ^2. It is preferable to consist of a magnification foam resin.

  The earthquake-resistant slit material according to the present invention is an earthquake-resistant slit material arranged at a joint portion between a non-structural wall and a structural portion of a reinforced concrete structure, and is made of a polystyrene-based low-magnification foamed resin having a foaming ratio of 5 times or less. It is preferable to become.

  Further, the building according to the present invention is a reinforced concrete building, and the earthquake-resistant slit material according to any one of the aspects described above is disposed at least at one of the joint portions between the non-structural wall and the structural portion. Features.

  In the present invention, the “limit compressive stress” refers to the maximum value of the compressive stress in a range where the foamed resin can exhibit buffering performance. When compressive stress exceeding the limit compressive stress acts on the foamed resin, Even when a large compressive stress is applied to the resin, the strain changes only slightly (in other words, the stress rapidly increases with a slight increase in strain).

  Generally, a foamed resin exhibits properties as an elastic body up to 3% strain compressive stress (yield point). When the stress exceeds that, bubbles in the foam collapse, so even if a small compressive stress is applied to the foamed resin. It shows plastic deformation whose strain changes greatly. The critical compressive stress value is a value at the time when the collapse of the bubble is almost finished, and if this value is exceeded, the strain changes only slightly even when a large compressive stress is applied (in other words, the strain increases slightly). The stress increases rapidly). Therefore, the range in which the foamed resin can exhibit the buffer performance can be defined as 3% strain compressive stress (yield point) or more and not more than the limit compressive stress value. The low-magnification foamed resin has a larger limit compressive stress value than the high-magnification foamed resin.

  When the corner portion of the concrete non-structure portion comes into contact with the structure portion due to interlayer deformation at the time of an earthquake, when the contact surface becomes partial, concentrated stress is generated at the corner portion, so that the portion is damaged. Dispersion of concentrated stress transmitted to the concrete due to deformation of the earthquake-resistant slit material by using low-magnification foam resin with a critical compressive stress that is smaller than the allowable compressive stress of concrete and the same level as the stress. it can.

  The low-magnification foamed resin also has self-supporting properties. Therefore, when such low-magnification foamed resin is used as an earthquake-resistant slit material, even if compressive stress acts on the earthquake-resistant slit material due to an earthquake shake, the earthquake-resistant slit material is stress-distributed if it is below the limit compressive stress. It behaves as a material and avoids unstructured walls from damaging the structure.

  On the other hand, non-structural walls are not designed to contribute to the structural strength of buildings, but if the inter-layer deformation angle can be secured, the non-structural walls maintain the shape of the structural parts when the structural parts such as columns are deformed. It can function as a reaction force wall of the deformation force to be caused. In other words, the non-structural wall improves the proof stress of the structural portion (deformation can be suppressed). That is, in the range where the seismic slit material exhibits the behavior as a stress dispersion material, the structural strength is improved without the non-structural wall damaging the structural portion. However, if the critical compressive stress of the seismic slit material exceeds the allowable compressive stress of the concrete used for the building, in order to convey the allowable compressive stress of the concrete, leaving the ability of the seismic slit material to exhibit buffer performance, There is a risk of destroying the structure without securing the interlayer deformation angle of the structure. On the other hand, as the critical compressive stress of the seismic slit material becomes smaller than the allowable compressive stress value of concrete, the concentrated stress at the corners of the non-structured part is transmitted to the structural part without breaking the concrete without transmitting the shape maintenance force to the structure. End up. Therefore, the seismic slit material can achieve its intended purpose because the critical compressive stress of the foamed resin composing the seismic slit material is the same as or close to the allowable compressive stress of the concrete of the building. it can.

Generally, the allowable compressive stress of concrete used in a reinforced concrete building is in the range of 10-40 N / mm ² . Therefore, according to the present invention, in one aspect of the earthquake-resistant slit material, the earthquake-resistant slit material is composed of a low-magnification foamed resin having a limit compressive stress in the range of 10 to 40 N / mm ² . In another aspect, the material having such a limit compressive stress value is made of a polystyrene-based foamed resin having a foaming ratio of 5 times or less.

  The low-magnification foamed resin having the above physical properties has self-supporting properties and high compression resistance. Therefore, it can be easily fixed to a concrete form or the like by nailing or the like. As a result, by using the earthquake-resistant slit material according to the present invention, the operation of arranging the earthquake-resistant slit material at the joint portion between the non-structural wall and the structure portion of the reinforced concrete structure is extremely easy and the workability is improved.

  Preferably, the seismic slit material is partially provided with a refractory material. The refractory material may be bonded to the front surface and / or the back surface of the seismic slit material, and may be embedded in the transverse and / or longitudinal direction. Examples of the refractory material include materials such as a butyl rubber sheet (trade name: Fibrok manufactured by Sekisui Chemical Co., Ltd.) containing thermally expandable graphite.

  According to the present invention, even when a vibration exceeding the design value occurs, an earthquake-resistant slit material made of low-magnification foamed resin that can improve the structural strength by avoiding damage to the structural portion of the non-structural wall, And the building of a reinforced concrete structure which arrange | positioned the earthquake-resistant slit material in the junction part of a non-structure wall and a structure part is obtained. Moreover, the installation work in a formwork can also be simplified and the seismic slit material which can improve workability by it is obtained.

The schematic diagram which shows the relationship between the non-structural wall and structure part in a reinforced concrete structure building. The 1st schematic diagram which shows one state when the building shown in FIG. 1 shakes. The 2nd schematic diagram which shows one state when the building shown in FIG. 1 shakes. The graph which shows the foaming ratio of a polystyrene-type foaming resin, and the relationship of distortion-stress.

  Hereinafter, the present invention will be described with reference to embodiments.

  FIG. 1 schematically shows an example of the relationship between a non-structural wall and a structural part in a reinforced concrete structure with a rigid frame structure. In the building shown in the figure, a reinforcing bar structure for floors, columns, and beams is assembled into a ramen structure, and concrete is cast to form a floor 1, a column 2, and a beam 3 as a structural portion. A hanging wall 4 is attached to the beam 3 in a suspended manner, and the hanging wall 4 constitutes an example of a non-structural wall. Other non-structural walls include a waist wall and a sleeve wall.

  In such a reinforced concrete building with a ramen structure, the structural part such as the pillar 2 is designed to be deformed at the time of an earthquake, and the vertical wall 4 is not disturbed by the non-structural wall which is the vertical wall 4. A gap (seismic joint) 5 is provided between the (non-structural wall) and the structural portion which is the floor 1 and the pillar 2, and both are cut off. Usually, the gap (seismic joint) 5 between the pillar 2 and the vertical wall 4 is set to a size that can follow the 1/100 interlayer deformation angle generated in a building during an earthquake.

  The gap 5 is normally closed by a joint material 6, and the joint material is called an earthquake-resistant slit material 6. In the illustrated one, the earthquake-resistant slit material 6 is also buried in the gap between the vertical wall 4 and the floor 1. Conventionally, a high-magnification foamed resin having a foaming ratio of about 50 to 80 is used for the earthquake-resistant slit material 6.

  It is assumed that a horizontal shaking (movement) occurs in the building as shown by an arrow P in FIG. 2 due to the earthquake. If the horizontal movement due to shaking is in the range of the 1/100 interlayer deformation angle which is the design value, the vertical wall 4 and the column 2 do not collide. However, when the vibration exceeding the design value occurs, the high-magnification foamed resin reaches the limit compressive stress without affecting the deformation force generated in the vertical wall 4 and the column 2, and as shown in FIG. The lower corner portion and the vicinity thereof are in direct contact with the pillar 2. Thereby, the lower corner 4a of the vertical wall 4 and the vicinity thereof and the pillar 2 are broken. Therefore, in the present invention, by using a low-magnification foamed resin having a high shock-absorbing property as the earthquake-resistant slit material 6, the direct contact between the vertical wall 4 and the column 2 is avoided, and the breakage does not occur. .

  FIG. 3 shows a state in which the same magnitude of vibration as shown in FIG. 2 occurs when the earthquake-resistant slit material 6a according to the present invention is employed. When a low-magnification foamed resin having a high shock-absorbing property is used as the earthquake-resistant slit material 6a, the earthquake-resistant slit material 6a is pressed against the pillar 2 together with the hanging wall 4 when the vibration occurs. If it is within the range in which the buffer performance can be exhibited, that is, within the range of the limit compression stress, the seismic slit material 6a supports the column 2 with the shape maintaining force of the vertical wall 4 while compressively deforming. At that time, the hanging wall 4 is also slightly deformed, but the seismic slit material 6a, which is a low-magnification foamed resin, functions as a stress dispersion material and is not damaged.

  That is, the seismic slit material 6a compresses and deforms in the gap generated between the vertical wall 4 and the column 2 but does not reach the allowable compressive stress of concrete. It is possible to avoid the portion 4a and the vicinity thereof from directly contacting the pillar 2, and as a result, it is possible to avoid the destruction of the lower corner portion 4a and the vicinity thereof and the damage of the pillar 2 as a structure.

  In addition, although not shown, the earthquake-resistant slit material 6a is bonded with a refractory material such as a butyl rubber sheet (product name: Fibro) manufactured by Sekisui Chemical Co., Ltd. that contains thermally expandable graphite. It is possible to avoid the spread of the material 6a and the sparks through the gap (earthquake resistant joint) 5.

By the way, the allowable compressive stress of concrete used in a general reinforced concrete building is in the range of 10 to 40 N / mm ² . Therefore, it is preferable that the aseismic slit material 6a is made of a low-magnification foamed resin having a limit compressive stress in the range of 10 to 40 N / mm ² .

Examples of the low-magnification foamed resin having such a critical compression stress include polystyrene-based low-magnification foamed resins having a foaming ratio of 5 times or less. FIG. 4 is a graph showing the relationship between the expansion ratio of the polystyrene-based foamed resin and the strain-stress. In general, the foamed resin exhibits properties as an elastic body within a strain range of about 3% or less. And the critical compression stress shows a low value, so that a foaming ratio is high. As shown in FIG. 4 and Table 1 below, in the case of polystyrene foam resin, critical compressive stress in expansion ratio 10 times is about ^{7N / mm 2, 10N / mm} 2 approximately in five times, the expansion ratio 1.7 times Then, the critical compressive stress is about 40 N / mm ² . Therefore, it is preferable to use a polystyrene-based low-magnification foamed resin having a foaming ratio of 5 times or less as the earthquake-resistant slit material 6a.

1 ... Floor as a structural part,
2 ... Pillar as a structural part,
3 ... Beam as a structural part,
4 ... Vertical wall as an unstructured wall,
5 ... Gap (earthquake resistant joint),
6, 6a ... Joint material (seismic slit material)

Claims (5)

  A seismic slit material arranged at the joint between a non-structural wall and a structural part of a reinforced concrete building, the seismic slit material being at or near the allowable compressive stress of the concrete used in the building An earthquake-resistant slit material characterized by comprising a low-magnification foamed resin having a limit compressive stress. A seismic slit material arranged at a joint between a non-structural wall and a structural part of a reinforced concrete building, characterized by comprising a low-magnification foamed resin having a limit compressive stress in the range of 10 to 40 N / mm ^2. The earthquake-resistant slit material according to claim 1.   An earthquake-resistant slit material disposed at a joint between a non-structural wall and a structural part of a reinforced concrete building, wherein the foaming ratio is made of a polystyrene-based low-magnification resin having a foaming ratio of 5 times or less. The earthquake-resistant slit material according to 1 or 2.   The quakeproof slit material according to any one of claims 1 to 3, wherein a refractory material is provided in part.   It is a reinforced concrete building, and the earthquake-resistant slit material according to any one of claims 1 to 4 is arranged at least at one of the joint portions between the non-structural wall and the structural portion. Building.

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