JPH0425139B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a sound insulation structure that improves the sound insulation properties of a multi-wall structure, particularly a multi-wall structure called a GL method wall.

(Prior Art) In recent years, in order to deal with problems such as residential noise, research and development of many sound insulation technologies and materials have been carried out. In addition, building materials are required to have higher performance. That is, insulation, weight reduction, and non-combustibility are required from the viewpoints of saving resources, energy, and improving safety, and thinning is required from the viewpoint of expanding space and improving workability. For this reason, sound insulating materials and sound insulating structures that meet these requirements are now required. This trend can also be seen in concrete housing complexes, mainly condominiums. Generally called the GL method, which uses gypsum board as a surface material and attaches dots to the concrete slab surface using an adhesive, it is said to be an extremely superior construction method in terms of ease of construction, nonflammability, construction cost, etc. The GL construction method achieves the above advantages by using a gypsum board with a thickness of about 9 mm and adhesive, but on the other hand, the sound insulation performance deteriorates significantly due to resonance transmission and coincidence effects. This has led to improvements being made as an important issue.

The sound insulation performance of this GL method wall is improved in the mid-range by adding a surface material and a hollow layer compared to a single concrete slab wall, but it is due to resonance transmission in the low-frequency range and the coincidence effect of the surface material in the high-frequency range. This results in a significant sound insulation loss, that is, a performance drop of approximately 10 dB or more. This causes serious noise problems between neighboring rooms.

(Problems to be Solved by the Invention) Various countermeasures have already been attempted to address the above sound insulation deficiency in the GL construction method. For example, it is possible to make the surface material into a vibration damping structure, make the surface material multi-layered or heavier, expand the air layer, change the adhesive construction pattern, add elastic material to the adhesive part, etc.
In either case, the advantages of the GL construction method are retained, but the effect of improving the sound insulation deficiency described above cannot be demonstrated. For this reason, the GL method does not use adhesives,
The method of constructing gypsum boards (surface material) using wooden fixing frameworks is being converted, but this cannot be called the GL construction method described above;
It is vastly inferior to the GL construction method in terms of workability and cost. Moreover, the problem of sound insulation deficiency described above has hardly been improved.

In this way, improving sound insulation defects in GL construction walls is considered to be a very difficult problem.

(Means for solving the problem) The present inventor has already proposed improvement of the sound insulation deficiency of the GL method wall in patent application No. 58-115192, etc., but it has also been proposed by another method. We have discovered that this can be improved, leading to the present invention.

While most of the conventional ideas aim at damping the vibration of the surface material or significantly shifting the missing frequency all at once, the present invention aims to improve the acoustic behavior of each part of the surface material on both opposing sides of the wall. The aim is to significantly improve the sound insulation deficit by making the areal density non-uniform and making the sound insulation deficit frequencies of the transmitted sound of each part slightly different. A sound insulating structure in which a hollow layer is provided on both sides of a natural wall material and each surface material is applied, and each surface material is formed on both sides of the structure and has a different weighted average areal density. Pertains to.

In addition, if the two facing materials facing the heavy wall material are S and S', and the weighted average surface densities of S and S' are m and m', respectively, then the larger of m and m' The ratio of small to small (m/m' if m>m') is preferably 1.2 or more, and more preferably 1.5 or more. Also,
If one side of the heavy wall material is the A side and the other side is the B side, the surface density of one or both of the surface material on the A side and the surface material on the B side can be made inhomogeneous within the same surface. It's okay.

The sound insulation structure according to the present invention will be explained below. The reason why the present invention can improve sound insulation defects is considered to be as follows.

First, in the case of a structure in which a lightweight surface material is provided on a heavy wall material with extremely large mass and rigidity, such as a GL method wall, the surface material and hollow layer on both sides A and B and the heavy wall material The five-layer structure composed of is large, especially in the low-frequency resonant transmission frequency region (hereinafter referred to as the frmd region)
Then, this structure behaves as if it were a combination of two double walls, the A side and the B side. When double wall resonance occurs in this double wall structure, the amplitude of the surface material is extremely large compared to the amplitude of the heavy wall material, so
This is because the resonance amplitude of the heavy wall material can be virtually ignored, and the resonance vibration of both surface materials becomes an important factor. Therefore, when the two frmd regions (missing frequency regions) of the A side and the B side coincide, the sound transmission loss (T, L) drops extremely significantly in this frequency range. On the other hand, if the surface densities of the surface materials in the opposing areas of both sides A and B are made to differ by more than a predetermined value, the respective frmd ranges will not match, and the sound insulation of the frmd range will change depending on the width of movement of the mutual frequency ranges. It was found that the defects were improved. This also applies to the vibration inherent to the surface material, which is different from the resonance of the double wall, and this effect becomes particularly noticeable when the natural frequency of the plate is close to the resonant frequency. I also understood that.

Furthermore, the degree of resonance caused by incident sound or transmitted sound in each part of the sound insulation structure, that is, the amplitude of the surface material due to resonance, changes depending on the conditions of the component area, but is the same over the entire area. Compared to a structure that maintains the resonant frequency, a structure that has a different resonant frequency has a lower resonance level, and the resonance state that occurs in one area causes attenuation in another area that has a different areal density. This decreasing effect changes depending on the inhomogeneous pattern between multiple regions with different areal densities of the surface material, but as the inhomogeneous region becomes smaller, the attenuation within the same surface material increases and becomes larger. It was found that the attenuation between materials with different surfaces increases relatively as the shape changes. Therefore, when both surface materials are composed of homogeneous areal densities, in order to improve the sound insulation deficiency described above, it is necessary to make the surface densities of the two facing materials different, and preferably Areal density ratio 1.2
A difference of 1.5 or more is required.

On the other hand, when making the areal density within the same surface material inhomogeneous, if the diameter of the maximum circle included in the inhomogeneous area is 3 cm or more, preferably 10 cm or more, the vibration behavior is different from that of the surrounding areas. This makes it easier to separate the missing frequencies, making it easier to disperse the missing frequencies.

In addition, as the surface material, it is preferable to use one having an areal density ratio (weighted average) of 0.3 or less with respect to the heavy wall material.

Here, as heavy wall materials, concrete slab walls, mortar walls, stone walls, brick walls, etc. are used, and as surface materials, gypsum boards, plywood, plastic boards, etc. are used.

(Examples) The present invention will be further explained below based on Examples.

Comparative Example 1 Adhesives 4 and 4' are applied to both sides of a concrete slab wall 1 with a thickness of about 14 cm as shown in Fig. 1 at lattice points of about 30 cm as shown in Fig. 2, and the area density of 6.8 is applied from above. Two 0.9 x 1.8 m gypsum boards ² and 2' each having a weight of Kg/m 2 and a thickness of 9 mm were pasted together with hollow layers 3 and 3'. The thickness of the hollow layers 3, 3' at this time was approximately 15 mm, and the adhesive area ratio of the adhesive to the total wall area was approximately 20%. After the adhesive was completely cured, the sound transmission loss (T·L) of this GL method wall was measured. The results are shown in Figure 5. As shown in the figure,
Significant sound insulation defects appeared in the approximately 250 Hz and 4000 Hz regions, but this was due to a drop in the low frequency range and the high frequency range of the plasterboard, which is unique to GL construction walls. Although the double wall structure improves sound insulation in the midrange, the amount of sound reduction due to sound insulation loss also reaches approximately 10 to 15 dB.

Comparative Example 2 All the gypsum boards on the GL method wall in Comparative Example 1 were changed to heavy fossil gypsum boards with an areal density of 9Kg/ ^m2 ,
Similarly, sound transmission loss was measured. The results are shown in Figure 5. This method of wall construction is in line with increasing the weight of the facing material, which is considered to be a typical method for improving the sound insulation defects of GL method walls. However, as shown in the figure,
Although the bass range has shifted to the lower range side (deficit range: 200Hz) compared to the previous Comparative Example 1 (GL construction wall), the loss is still about 10-odd dB, and the sound insulation deficit has hardly been improved. In the high range, the missing frequency shifts to the middle range side, resulting in a rather unfavorable state, and the loss has hardly been improved.

Example 1 Adhesive was dotted in a grid pattern on both sides of the concrete slab wall used in Comparative Example 1 in the same manner as in Comparative Example 1, and the following surface material was applied. One surface material is a gypsum board with an areal density of 6.8Kg/m ² and a thickness of 9mm.
For the other surface material, the gypsum board has an areal density of 4.0Kg/
m ² , 1.1 mm thick soft sound insulation sheet (Zeon Kasei Co., Ltd.)
Sandum S10, manufactured by Komatsu, Ltd., a sheet made of vinyl chloride resin mixed with iron powder, etc.) was used. The sound transmission loss of this wall was also measured in the same manner as in Comparative Example 1. The results are shown in Figure 6.

As shown in the figure, the present example improves the loss by about 5 dB in the bass range and by about 5 dB in the treble range compared to the comparative example. In this example, the areal density ratio of the opposing surface materials was 6.8+4.0/6.8≈1.6.

Example 2 As a surface material, one side had the same surface density as Comparative Example 1.
A homogeneous gypsum board with a density of 6.8Kg/m ² is used, and the other is a gypsum board with the same surface density of 6.8Kg/m ² measuring 45 x 45cm.
Divide into areas and alternately apply Example 1 as shown in Figure 3.
The walls were constructed in the same manner as in Comparative Example 1, except that the soft sound insulating sheet (area density 4.0 Kg/m ² ) used in Comparative Example 1 was pasted (shaded area), and the sound transmission loss was measured. . The results are shown in Figure 6. The weighted average areal density ratio of opposing surface materials is 8.8/6.8≒1.29,
The diameter of the largest circle in the heterogenized region was 45 cm. As shown in the figure, compared to the comparative example,
6dB, improving the 5dB loss in the high frequency range.

Example 3 As a surface material, a gypsum board with an areal density of 6.8 Kg/m ² was divided into 6 areas of 60 x 90 cm as shown in Figure 4, and the soft sound insulating sheets used in Example 1 (area density 40Kg/m ² ) (shaded area), and the other is a gypsum board with an areal density of 9.0Kg/m ² 6
A wall was constructed in the same manner as in Comparative Example 1 by dividing the area into areas and alternately pasting the soft sound insulating sheets used in Example 1, and measuring the sound transmission loss. The results are shown in Figure 6. In constructing the wall, the opposing surface materials were arranged so that the weight area of one surface material corresponded to the light weight area of the other surface material.

The weighted average areal density of the opposing surface materials in this example was 11/8.8≈1.25, and the diameter of the maximum circle in the non-homogenized region was 60 cm. As shown in the figure, compared to the comparative example, the loss has been improved by 6 to 7 dB in the bass range and by 6 to 7 dB in the treble range.

(Effect of the invention) As described above, although the effect changes depending on the form of non-uniformity of the areal density of the surface materials, by making the areal densities of the opposing surface materials different by more than a predetermined value, it is possible to improve the bass and high frequency ranges. can significantly improve sound insulation deficiencies in The improvement effect is approximately 5 dB or more, making it possible to improve the sound insulation class (D-value) by one rank. This is extremely difficult to achieve using existing construction methods and structures. Examples of the invention
Although the explanation has been made based on the construction method, the present invention is not limited to the GL construction method, and also cases where the hollow layer is filled with a sound absorbing material or the like are naturally included in the present invention.

[Brief explanation of drawings]

Figure 1 is a partial cross-sectional view of the GL method wall, and Figure 2
The figure shows a state in which the adhesive is dotted on the surface material, FIGS. 3 and 4 are plan views of the surface material with non-uniform areal density, and FIG. FIG. 6 is a diagram showing the sound transmission loss of Examples 1-
FIG. 3 is a diagram showing the sound transmission loss of No. 3.

Claims (1)

[Scope of Claims] 1. In a structure formed by providing a hollow layer on both sides of a heavy wall material and applying each surface material, each surface material applied to both sides of the structure has a weighted average areal density. A sound insulation structure characterized by being configured differently. 2. The sound insulation structure according to claim 1, wherein the weighted average areal density ratios of both the surface materials are different from each other by 1.2 or more. 3. The sound insulation structure according to claim 1 or 2, wherein the surface material is composed of a plurality of regions having different areal densities.