JP2014037678A - Ceiling structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceiling structure excellent in fire resistance and incombustibility and capable of producing the great effect of reducing floor impact sounds on an upper floor.SOLUTION: A ceiling structure 1 includes an upper structure 2, a ceiling 3 that is formed with a clearance below the upper structure 2, and a sound absorbing body 4 that is placed on the ceiling 3. In the ceiling structure 1, the sound absorbing body 4 has a granular material 41 and a container 42 for housing the granular material 41, and the granular material 41 is perlite, a natural glass foam, sand or a mixture of at least two of them.

Description

  The present invention relates to a ceiling structure for floor impact noise countermeasures.

  The floor impact sound is a sound that is generated in a lower floor room by vibrations with a wide frequency component depending on the softness and impact time of the impact that is applied. It may cause trouble. Such floor impact sounds can be classified into light floor impact sounds caused by furniture dragging and falling of small items and heavy floor impact sounds caused by human jumping and jumping.

Conventionally, many countermeasure structures for reducing floor impact noise have been developed.
For example, Patent Documents 1 and 2 disclose a ceiling structure including a ceiling slab, a sound-absorbing perforated board provided below the ceiling slab, and bag-packed charcoal laid on the perforated board. .

  The charcoal of Patent Document 1 has 90% by weight or more with a major axis of 15 mm or less and a bulk density of 0.104 to 0.151 kg / l. The charcoal of Patent Document 2 has a ratio of that with a major axis of 4.75 mm or more. The volume ratio of the total length is less than 20% by weight and the major axis is in the range of 4.75 to 2.36 mm is larger than the volume ratio of the major axis in the range of 2.36 mm or less.

  Moreover, in patent document 3, a frame material, the hollow beam material spanned over the inner side of this frame material, and the granular material accommodated in the hollow part of the beam material are arrange | positioned on the lower surface of a floor board. A floor structure is disclosed.

Further, Patent Document 4 discloses a ceiling structure including a ceiling slab, a ceiling material provided below the ceiling slab, and a powder layer having a thickness of 5 mm or less installed on the upper surface of the ceiling material. . In this ceiling structure, it is desirable to use a powder having an average particle diameter in the range of 0.1 to 1000 μm and a bulk density in the range of 0.1 to 1.5 g / cm ³ .

Japanese Patent No. 4550609 JP 2010-31599 A JP 2006-125195 A JP-A-9-228535

  The ceiling structures described in Patent Document 1 and Patent Document 2 are difficult to adopt in buildings with a fireproof / noncombustible structure because the charcoal disposed behind the ceiling is a combustible material.

  Moreover, the floor structure of patent document 3 was not employable for the building provided with the floor slab (ceiling slab) made from concrete.

  Furthermore, although the ceiling structure of Patent Document 4 is effective in the frequency band of lightweight impact sound with a floor impact sound level of 125 to 500 Hz, the effect is hardly obtained in the frequency band of 63 Hz of heavy floor impact sound. .

  The object of the present invention is to solve the above-mentioned problems, and is superior in fire resistance and non-flammability, and can be applied not only to a new building but also to a renewal. It is an object to propose a ceiling structure with a high reduction effect.

  In order to solve the above-mentioned problems, a ceiling structure according to the present invention is a ceiling structure including an upper structure, a ceiling formed below the upper structure, and a sound absorber mounted on the ceiling. The sound absorber has a granular body and a container for containing the granular body, and the granular body is pearlite, natural glass foam, sand, or a mixture of at least two of these. It is characterized by being.

According to the ceiling structure, the floor impact sound can be effectively reduced since the vibration energy is attenuated by moving the granular material in the container by vibration.
Moreover, since a nonflammable material is used as the granular material, a ceiling structure excellent in fire resistance and nonflammability can be constructed.

  The granular body has a bulk specific gravity of 0.2 or less and an average particle diameter in the range of 10 mm or more and 20 mm or less, a bulk specific gravity of 0.2 or more, and an average particle diameter of If it includes the second granular material within the range of 0.2 mm or more and less than 0.5 mm, the granular material moves even with a small vibration, so that the vibration energy can be attenuated more effectively.

By disposing the sound absorber so as to satisfy Equation 1, it is possible to more effectively obtain a floor impact sound reduction effect.
M> E / 4050π ² · 1 / d−ρ · t Equation 1
Here, M: mass per unit area of the sound absorber (kg / m ² )
E: Air bulk modulus (N / m ² )
d: Distance between upper structure and ceiling (m)
ρ: Density of the ceiling board constituting the ceiling (kg / m ³ )
t: Thickness of ceiling board (m)

  Further, when the container is placed on the ceiling plate of the ceiling in a state of straddling the edge of the ceiling, it is possible to attenuate the vibration of the base material, and to more effectively reduce the floor impact sound. Can do.

  Furthermore, if the said container is a bag which consists of glass cloth, the ceiling structure excellent in fire resistance can be comprised.

  According to the ceiling structure of the present invention, it is possible to construct a ceiling that is excellent in fire resistance and non-flammability and has a high effect of reducing floor impact sound on the upper floor.

It is sectional drawing which shows the outline | summary of the ceiling structure which concerns on embodiment of this invention. It is a perspective view which shows the ceiling structure of FIG. (A) is a top view which shows a ceiling (ceiling structure which omitted the sound-absorbing body), (b) is a top view which shows a ceiling structure. (A)-(c) is a top view of the ceiling structure which concerns on another form. (A) is a top view of the small ceiling test body used for verification experiment, (b) is an elevational view. It is a figure which shows a verification experiment result, Comprising: It is a graph which shows the difference in the vibration acceleration level reduction amount by the difference in the average particle diameter of a granular material. (A) And (b) is a figure which shows a verification experiment result, Comprising: It is a graph which shows the difference in the floor impact sound level by the presence or absence of the container of a sound absorber.

  As shown in FIG. 1, the ceiling structure 1 of this embodiment includes an upper structure 2, a ceiling 3 formed below the upper structure 2, and a sound absorber 4 mounted on the ceiling 3. .

The upper structure 2 is a building frame portion made of a ceiling slab, a beam, or the like. The upper structure 2 of the present embodiment is a reinforced concrete material. The upper structure is not limited to reinforced concrete material.
A plurality of suspension bolts 5 and 5 are suspended from the upper structure 2.

The suspension bolt 5 suspends the ceiling 3 by having the upper end fixed to the upper structure 2 and the lower end fixed to the ceiling 3.
Note that the number and arrangement of the suspension bolts 5 are not limited, and may be set as appropriate according to, for example, the weight of the ceiling 3.

  The ceiling 3 is a so-called double ceiling (suspended ceiling) suspended by suspension bolts 5, and is disposed horizontally with a gap (place) between the upper structure 2. The ceiling 2 is not necessarily horizontal and may be inclined.

As shown in FIG. 2, the ceiling 3 of the present embodiment includes a ceiling plate 31, a field edge 32, and a field edge receiving member 33.
The ceiling plate 31 is a plate material that covers the lower surface of the ceiling 3. In addition, although the material of the ceiling board 31 is not limited, what is lightweight and excellent in the sound-insulating property is desirable.

The field edge 32 is a bar-like member that holds the ceiling board 31 and is fixed to the upper surface of the ceiling board 31.
The field edge 32 of the present embodiment is a steel base material defined by JIS A 6517 building steel base material (wall / ceiling) or a steel base material such as a square stud that is generally used. In addition, the kind of shape material which comprises the field edge 32 is not limited, For example, using shape materials, such as cross-sectional C-shape, cross-sectional U-shape, cross-section L-shape, cross-section R-shape, is used. it can. Further, the material of the field edge 32 is not limited, and may be, for example, an aluminum alloy, stainless steel, a wood material, or the like.

  The field edge receiving member 33 is a rod-like member that holds the field edge 32, and is fixed to the upper surface of the field edge 32 via an attachment fitting (not shown) in the present embodiment. In addition, the fixing method of the field edge 32 and the field edge receiving material 33 is not limited, For example, you may fix directly by fastening parts, such as a screw, and you may fix by welding.

  The field edge receiving material 33 is suspended by the suspension bolt 5. The member that supports the field edge receiving member 33 is not limited to the suspension bolt 5.

The field edge receiving material 33 is a steel base material defined in JIS A 6517 building steel base material (wall / ceiling) or a steel base material such as a square stud that is generally used.
In addition, the kind of shape material which comprises the field edge receiving material 33 is not limited, For example, shapes, such as cross-sectional C-shape, cross-sectional U-shape, cross-section L-shape, cross-section R-shape, are used. be able to. The material of the field edge receiving member 33 is not limited, and may be, for example, an aluminum alloy, stainless steel, a wooden material, or the like.

  As shown in FIG. 3A, the field edge receiving member 33 is arranged in a direction intersecting with the field edge 32. In other words, the ceiling 3 includes a lattice-like ceiling base formed by the field edge 32 and the field edge receiving member 33.

As shown in FIG. 1, the sound absorber 4 includes a granular body 41 and a container 42 that houses the granular body 41.
The granular material 41 of the present embodiment is composed of obsidian pearlite, which is a kind of pearlite (a foam obtained by heating glassy volcanic rock). In addition, the material which comprises the granular material 41 is not limited to this, For example, if it comprises with a pearlite pearlite, natural glass foam, sand, or what mixed these at least 2 Good.

  The granule 41 has a bulk specific gravity of 0.2 or less and a particle size distribution of 3 mm or more and 25 mm or less (average particle size of 11.2 mm to 16.2 mm), pearlite (first granule), Perlite (second granular material) having a bulk specific gravity of 0.2 or more and a particle size distribution of less than 1.2 mm (average particle size of 0.25 mm to 0.5 mm) is mixed. In the present embodiment, the first granule and the second granule are mixed at a ratio of 10: 9, but the blending of the first granule and the second granule is not limited, and the first granule: It is desirable to blend so that the second granular material is within the range of 1: 1 to 4: 1 and the first granular material ≧ the second granular material.

  The container 42 is a bag made of glass cloth. In addition, although the material which comprises the container 42 is not limited, It is a material which does not inhibit a movement of an internal granule when it vibrates, Comprising: A nonflammable and fireproof material is desirable.

In the present embodiment, as shown in FIG. 3B, the sound absorber 4 is disposed on the entire surface of the ceiling 3.
Note that the sound absorbers 4 do not necessarily have to be arranged on the entire surface of the ceiling, and the sound absorbers 4 may be partially arranged as shown in FIGS. For example, as shown in FIG. 4 (a), it may be arranged so as to avoid the field edge receiving material 33, or as shown in FIG. 4 (b), arranged in rows at predetermined intervals. May be. Further, as shown in FIG. 4C, the suspension bolts 5 may be disposed so as to be avoided.

  As shown in FIGS. 1 and 2, the sound absorber 4 is in contact with the ceiling plate 31 in a state of straddling the field edge 32. That is, the central portion of the container 42 is located on the field edge 32, and both sides of the container 42 are placed on the upper surface of the ceiling board 31 on both sides of the field edge 32.

As shown in FIG. 2, at the position where the field edge receiving material 33 is disposed, the sound absorbers 4 are disposed on both sides of the field edge receiving material 33.
In addition, the mass of the granular material 42 is determined by Equation 1.

  In addition, Formula 1 is a formula derived by expanding the formula (Formula 2) of the resonance frequency f as shown below.

  According to the ceiling structure 1 of the present embodiment, the granular body 41 of the sound absorbing body 4 disposed on the upper surface of the ceiling 3 moves even with slight vibrations and absorbs vibration energy. Moreover, since the internal attenuation of the field edge 32, the field edge receiving material 33, and the ceiling 3 constituting the ceiling 3 is originally small, the floor impact sound can be effectively reduced. When the vibration is applied, the granular body 41 moves in the container 42, thereby attenuating vibration energy by friction or collision between particles or particles and the container 42.

  Further, according to the ceiling structure 1, the vibration energy is attenuated on the upper surface of the ceiling plate 31 that is the final radiation surface of the floor impact sound, so that the amplification of the floor impact sound caused by the installation of the double ceiling is suppressed. And a big reduction effect can be acquired compared with before installation.

  Since a mixture of a plurality of materials (first granule and second granule) having different bulk specific gravity and average particle size is used as the granule 41, the frequency range where the effect is obtained is wide. Therefore, an effect can be expressed with respect to both the lightweight floor impact sound and the heavy floor impact sound.

  Moreover, since the mass of the granular material 41 is calculated by the ceiling space d (m), the density ρ (kg / m 3) of the ceiling plate 31, and the thickness t (m) of the ceiling plate 1, The amplification range due to the resonance phenomenon determined by the mass and the air spring at the ceiling is determined in a lower frequency band than the 63 Hz band which is a general frequency floor impact sound determination frequency band, and the reproducibility of the effect is high.

  Since the sound absorber 4 is disposed across the field edge 32, the vibration of the base material (field edge 32 and field edge receiving material 33) can also be attenuated.

  Since the sound absorbing body 4 is made of pearlite, which is an incombustible material, as a granular body 41 and a bag made of glass cloth, which is an incombustible material, is used as a container 42, the sound absorbing body 4 has high fire resistance and incombustibility.

  The ceiling structure 1 can reduce the floor impact sound simply by arranging the sound absorbers 4 on the top surface of the ceiling 3, so that floor impact sound can be reduced from the sound receiving room (lower floor room), regardless of whether it is installed or not. It can be performed. Moreover, it can employ | adopt, without being limited to the structural form (Reinforced concrete structure, steel frame structure, wooden structure, etc.) of an applicable building.

Further, unlike a damper or the like, it is not necessary to perform tuning in advance, and it can be applied to many properties in a short time.
Since it is not necessary to use a special member such as a perforated plate for the ceiling plate 31, the degree of freedom of the design on the indoor side is not limited.

  The ceiling structure 1 of the present embodiment is a floor impact sound reduction technology that can be applied not only at the time of new construction but also at the time of renewal, and in particular, a heavy floor that is closely related to structural specifications such as floor slab thickness and beam addition / position change. This is a floor impact noise reduction technology that does not require structural changes to the impact sound.

Next, the result of a demonstration experiment conducted to confirm the vibration reduction effect of the sound absorber is shown.
In this experiment, as shown in FIGS. 5A and 5B, in a small ceiling test body formed using wall columns 6 and 6, an impact P was applied to the floor slab 7 by a heavy impact source, and the ceiling The vibration acceleration level transmitted to 3 was measured.

First, pearlite (sample A: “Pacific Perlite Special M-1” manufactured by Taiheiyo Materials Co., Ltd.) having a particle size distribution in the range of 3.0 to 25.0 mm (average particle size of 11.2 mm to 16.2 mm) Pearlite (sample B: “Pacific Perlite M-1” manufactured by Taiheiyo Materials Co., Ltd.) having a particle size distribution in the range of 3.1 to 15.0 mm (average particle size of 3.7 mm to 7.7 mm), and particle size Perlite (sample C: “Pacific Perlite M-2” manufactured by Taiheiyo Material Co., Ltd.) having a distribution of less than 5.0 mm (average particle size of 1.2 mm to 2.4 m) and a particle size distribution of less than 1.2 mm (average) For pearlite (particle diameter: 0.25 mm to 0.5 mm) (sample D: “Pacific Perlite 5” manufactured by Taiheiyo Material Co., Ltd.), the effect of reducing vibration acceleration level was measured. It was.
The results are shown in FIG.

As shown in FIG. 6, the reduction effect was obtained with all the materials.
In particular, in a low frequency band (frequency is 90 Hz or less), Sample A and Sample B having an average particle diameter of 3 mm or more are effective, and in a high frequency band (frequency is 90 Hz or more), Sample C having an average particle diameter of less than 3 mm. Sample D was effective.

  From this result, it is proved that the vibration reduction effect can be obtained for a wide frequency band when the granular body 41 is mixed with a granular body having an average particle diameter of 3 mm or more and a granular body having an average particle diameter of less than 3 mm. It was.

Next, when only a general ceiling is constructed (when the granule 41 and the container 42 are not arranged, tests E1 and E2), the sound absorber 4 in a state where the granule 41 is put in the container 42 is attached to the ceiling 3. The floor impact sound was measured when placed on the upper surface (tests F1 and F2).
The results are shown in FIG. 7A shows the case where the sound absorber 4 is arranged on the entire surface of the ceiling 3, and FIG. 7B shows the case where the sound absorber 4 is partially arranged.

  As shown in FIGS. 7A and 7B, the test results F1 and F2 in which the granule 41 is placed in the container 42 and placed on the ceiling 3 result in a lower floor impact sound than the general ceiling. It became.

DESCRIPTION OF SYMBOLS 1 Ceiling structure 2 Superstructure 3 Ceiling 4 Sound absorber 41 Granule 42 Container

Claims (5)

A superstructure;
A ceiling formed below the upper structure;
A sound absorbing body mounted on the ceiling, and a ceiling structure comprising:
The sound absorber has a granular body and a container for housing the granular body,
The ceiling structure according to claim 1, wherein the granular material is pearlite, natural glass foam, sand, or a mixture of at least two of them.   The granular body has a bulk specific gravity of 0.2 or less and an average particle diameter in the range of 3 mm to 20 mm, a bulk specific gravity of 0.2 or more, and an average particle diameter. The ceiling structure according to claim 1, further comprising a second granular body that is within a range of 0.2 mm or more and less than 3 mm. The ceiling structure according to claim 1, wherein the sound absorber is disposed so as to satisfy Formula 1.
M> E / 4050π ² · 1 / d−ρ · t Equation 1
Here, M: mass per unit area of the sound absorber (kg / m ² )
E: Air bulk modulus (N / m ² )
d: Distance between upper structure and ceiling (m)
ρ: Density of the ceiling board constituting the ceiling (kg / m ³ )
t: Thickness of ceiling board (m)   The ceiling structure according to any one of claims 1 to 3, wherein the container is placed on a ceiling plate of the ceiling in a state of straddling the edge of the ceiling. The ceiling structure according to any one of claims 1 to 4, wherein the container is a bag made of a glass cloth.

Images