EP3310965B1 - Noise-absorbing component, and noise-protection wall comprising such a component - Google Patents

Description

The present invention relates to a sound-absorbing component, which preferably has a plate-like basic shape but can also be produced in other shapes. The sound-absorbing component comprises a sound-absorbing cover layer and sound absorber elements embedded therein with a degree of absorption that is relevantly increased relative to the cover layer.

With increasing noise pollution, especially in the vicinity of traffic routes, the need for the construction of noise barriers in outdoor areas has increased significantly in recent years. Sound-absorbing components are not only needed on roads and railway lines, but also used, for example, in commercial areas with increased noise pollution. An acoustic objective is the most comprehensive possible absorption of sound or noise in a wide frequency range. In addition, the sound-absorbing components used in outdoor areas must be weather-resistant for a long time and also meet mechanical requirements that may result, for example, from a high wind load or possibly vandalistic attacks. Today, there are virtually no materials available that have both a high mechanical strength and resistance to environmental influences as well as a high degree of sound absorption over a wide frequency range.

In Scholl, W .: "Development and Application of Noise Protection Walls", Fraunhofer Institute for Building Physics, IBP Communication 234, 20 (1993 ) explains the basics of absorption properties to be implemented on noise barriers.

From the EP 0 417 049 A1 a plate element for a noise barrier is known, which is composed of several layers of material. In this case, a carrier layer is formed by interconnected wooden boards, on which in the direction of the sound source, a continuous layer of rock wool or comparable fiber material is applied. This noise-absorbing layer is covered over its entire surface by another layer of a cement-bonded, porous material. The material and manufacturing costs for such plate elements is high. The total thickness of the plate element must be large if useful absorption properties are to be achieved. Overall, this plate element exhibits suitable absorption properties only in certain frequency ranges, since substantial frequency ranges are either already reflected on the continuous cover layer or can not be sufficiently absorbed by the enclosed rock wool layer, resulting in undesirable reflection of the sound on the rear wooden wall. The enclosed rock wool is also sensitive to moisture, so that the plate elements either have to be laboriously sealed or the sound-absorbing properties diminish over time.

In the EP 1 508 650 B1 a method for producing a noise barrier of sound absorbing components is described. An embodiment of the device produced thereafter has a concrete support plate, to which one or two sided attachment shells are attached, which contain sintered expanded glass. Although sintered expanded glass is basically weather-resistant, it is more resistant to mechanical damage Stress very vulnerable. The facing shell of sintered expanded glass located on the outside of the sound-absorbing component is therefore already damaged under moderate mechanical stress, as can occur during the assembly process.

From the DE 197 12 835 C3 is a molded body made of a lightweight material known which has sound insulating properties.

The EP 0 548 856 B1 shows a visual and noise barrier wall with support beam construction. In a special embodiment, strongly profiled sound absorption profiles are mounted on a concrete support wall. The sound absorption profiles are made of lean-mixed lean concrete and have individual cavities that partially protrude into the lean concrete layer of the sound absorption profiles. To improve the sound insulation, these cavities can be filled with mineral wool. A disadvantage of this arrangement is the considerable profiling of the outwardly directed surface of the sound-absorbing profile, which, although leading to improved absorption properties, makes it impossible to use it with strong air currents, for example in the immediate vicinity of railways for high-speed trains. This also leads to a large total wall thickness and high weight.

In the DE 42 31 487 A1 discloses a sound absorbing wall element having a concrete support layer. In the support layer, a large-scale depression is incorporated, in which a covering layer of individual plate-shaped elements, consisting of haufwerksporigem concrete, is used throughout the area. The porous concrete slabs improve the absorption properties, while the mechanical Stability of the underlying support layer is deteriorated. To further improve the sound absorption are areal trained sound absorption plates between the haufwerksporigen concrete elements and the support layer. The intermediate sound absorbing panels substantially fill the entire area in the recess, except for minor non-exposed areas at the edges of the individual porous concrete slabs.

The DE 25 24 906 A1 describes a protective wall against noise immissions. The protective wall comprises a load-bearing, simultaneously sound-absorbing reinforced concrete wall and an absorption layer, which are connected to one another by gluing or needling. The absorption layer consists of open-pored and fabric-reinforced sheets of plastic-bonded elastomeric fibers. The reinforced concrete wall has a profiling with grooves in the boundary region to the absorption layer. The grooves may be partially or completely filled with a secondary absorbent material. Alternatively, the absorbent material may also be applied only as a coating in the grooves. Softened fine and open-cell foams are preferably suitable as secondary absorption materials.

The JP H10 46525 A shows a sound-absorbing plate and a method for their preparation. In this case, an open frame cement board is filled with rough concrete. By previously introduced and then removed pipes arise between the cement slab and the rough concrete cavities, which are filled with a sound-absorbing material. The sound-absorbing material has a different absorption to the rough concrete.

The object of the present invention is therefore to provide a sound-absorbing component which on the one hand satisfies the environmental influences and operating conditions prevailing in the outside and on the other hand has a significantly improved overall absorption, in particular in the frequency range between 800 and 2,000 Hz, but more preferably also in the frequency range around 500 Hz and below in order to use the sound-absorbing component in noise protection efficiently.

This object is achieved by a sound-absorbing component according to the appended claim 1.

The sound-absorbing component according to the invention is characterized in particular by the fact that the surface of the cover layer directed in the direction of the sound source is flat. Furthermore, the sound absorber elements are arranged at a distance from each other and each have at least one absorption surface which is parallel to the cover layer in a plane, wherein in this plane the area occupied by the sound absorber elements is smaller than the surface not occupied by sound absorber elements. The absorption surface of the sound absorber element is considered to be an area which is open to the entry of sound waves. The absorption surface can be free for this or covered by a sound-permeable material. An absorption surface thus represents, for example, a surface of the sound absorber element which lies on the outside of the cover layer or else is coated with a layer of cover layer material. The absorption surface is therefore also referred to below as an open absorption surface, without this being equivalent in all embodiments to an exposed surface.

The invention is based first of the finding that for the production of a sufficient mechanical strength and stability against environmental influences on the one hand and the achievement of a high overall absorption on the other hand, different materials must be combined, each their desired properties are exploited and at the same immanenten the respective materials Disadvantages can be compensated by other materials have to. This leads first to a partial solution, which is to be seen in that materials with a high degree of absorption are included in a material with a lower degree of absorption but higher mechanical strength, this partial aspect has already been isolated in the prior art. Moreover, it is essential for the invention to recognize that at the interfaces of contiguous, differently absorbing materials, acoustic interface effects occur which favor the absorption effect. In particular, sound wave diffraction, superposition of sound waves and absorption occur. The higher the difference of the flow resistances or absorption levels of the different materials, the larger are these interface effects. By exploiting these effects, it is possible to achieve higher absorption values, a broader absorption and an increase in the absorption in the low-frequency range. Such interfaces consist of two or more successive layers of different materials and along the already mentioned diffraction edges of in an absorber layer inserted absorber strip.

At the boundary lines between a highly absorbent material and a non-absorbing or poorly absorbing material, there is a diffraction of the sound waves arriving there, this diffracted sound wave component being superimposed with the sound waves to be absorbed, in order to partially or, in the best case, complete extinction of the sound waves reach, which leads to a significantly increased absorption rate. Such boundary lines are also referred to below as diffraction edges.

This knowledge makes use of the present invention, in a first embodiment, the diffraction edges in a Boundary level are formed on the surface facing away from the sound source surface of the cover layer. If the device according to the invention is attached to a carrier layer in preferred applications, this boundary plane lies between carrier layer and cover layer, so that said partial erasing effect occurs on the back side of the cover layer and thus both the superposed sound waves and the diffracted sound waves must again pass through the entire cover layer a particularly high degree of absorption results.

The invention is further distinguished by the fact that the sound absorber elements with an increased degree of absorption are completely or partially embedded in the cover layer and additionally have a frame element made of a sound-reflecting material. The frame member frames the sound absorbing member on one or more sides and subtends it from the material of the cover layer, leaving at least the absorption surface open to sound so as to allow sound waves to penetrate into the sound absorbing member. The surfaces of the sound absorber element, which are completely covered by the frame element, therefore represent no absorption surfaces, since the frame element substantially completely reflects incident sound waves. The surfaces of the sound absorber element, which are not covered by the frame member, however, represent absorption surfaces, as sound waves enter and are absorbed. At the interfaces between the sound absorber element and the frame element, the aforementioned diffraction edges are formed particularly effectively. In addition, the frame members may serve to secure the sound absorber elements in the cover layer.

The design according to the invention thus makes it possible to produce slender, smooth, weather-resistant, impact-resistant sound-absorbing components, predominantly using inexpensive (low-absorbing) materials and with only a small proportion of expensive (highly absorbent, more sensitive) materials. Thus, the components according to the invention can be used, for example, particularly advantageous for sound absorption on railway lines, where only a little distance from high-speed trains is regularly available, so that strong air turbulence and high noise pollution occur.

An advantageous embodiment is characterized in that the sound-absorbing cover layer has an absorption coefficient α _D = 0.3 to 0.75 and the sound absorber elements have an absorption coefficient α _S = 0.8 to 1.

According to a preferred embodiment, the volume fraction of the sound absorber elements enclosed in the cover layer is between 10% and 45% of the total volume of the cover layer. In particular, the cover layer consists of haufwerksporigem material.

It is expedient if a sound-permeable fabric layer, which at least partially spans the sound absorber elements, is attached to the surface of the cover layer facing away from the sound source. This offers the advantage that the stability of the component is increased overall and that the sound absorber elements are protected during transport and assembly and secured against falling out of the sound-absorbing component.

Particularly preferably, the sound absorber elements occupy an area of 20% in the surface of the cover layer facing away from the sound source and have a depth of 50% to 80% of the thickness of the cover layer.

According to a modified embodiment, further sound absorber elements, the degree of absorption of which is substantially higher than the absorption coefficient of the cover layer, can be embedded in a carrier layer, which adjoins the cover layer in a boundary plane. In the boundary plane thus also diffraction edges run, which extend along the lines of contact between the sound absorber elements and the carrier layer. In a further modified embodiment, the sound absorber elements extend beyond the carrier layer into the cover layer, so that even in this case the contact lines between the sound absorber elements and the carrier layer extend in the boundary plane.

Furthermore, it is essential for the invention that the individual sound absorber elements are arranged spaced from each other, so that as many as possible of the said diffraction edges arise. Finally, it is important that the area covered by the sound absorber elements in or parallel to the boundary plane comprises less than 50% of the total area of the boundary plane.

According to a preferred embodiment, the sound absorber elements in the boundary plane cover less than 40% of the total area, preferably less than 30%, more preferably less than 25%. Already by such small surface portions of the sound absorber elements made of highly absorbent material, surprising overall absorption values are achieved. This leads to a cost reduction for the sound-absorbing sound element.

A particularly preferred embodiment uses sound absorbing elements that cover an area of about 20% of the surface area of the cover layer. It has proved to be surprisingly appropriate to use strip-shaped sound absorber elements made of sintered expanded glass granules with a width of about 50 mm, which are spaced from each other by 200 mm. This leads to an optimized absorption rate at frequencies around 500 Hz. This design leads to a targeted improvement in the low-frequency range up to 500 Hz, especially for requirements in rail traffic (see, for example, guidelines for noise protection systems on railway lines - RLE).

It has been found that larger distances between the strip-shaped sound absorber elements lead to improved absorption in the higher-frequency range, so that in this way the sound-absorbing component can be adapted to a preferred spectrum to be absorbed. This leads to a targeted broadband improvement in the range 500 to 3000 Hz for the requirement "highly absorbent" in road traffic (see Additional Technical Regulations and Guidelines for the implementation of noise barriers on roads - ZTV-Lsw 06). Of course, by appropriate arrangement of several sound absorber elements with different distances from each other and improved absorption values both in the range below 500 Hz and in the range up to 3,000 Hz can be achieved.

The inventive combination of the highly absorbent material of the sound absorbing element with the worse but in a wider frequency range absorbing material of Top layer leads to a surprisingly significantly increased overall absorption in the frequency range around 500 Hz, when the aforementioned materials are used and the dimensions mentioned above are met. This is important for the use of sound-absorbing components on noise barriers. It is also of particular importance for the occurrence of this improvement that the absorber materials used (in particular sintered expanded glass granules) of the sound absorber element have stable acoustic properties.

Particularly preferably, the cover layer and the carrier layer adjoin one another in the boundary plane without leaving voids, optionally imparted via an adhesive layer, when the cover layer and the carrier layer are glued together. A particularly simple construction results if, in the case of directly adjacent carrier and cover layers, the sound absorber elements also end in the boundary plane and do not extend into the carrier layer. In modified embodiments, cavities are formed on the side of the carrier layer facing the boundary plane, which receive portions of the sound absorber elements which project beyond the cover layer.

The sound absorber elements preferably consist of a sintered expanded glass granulate which is preferably strip-shaped or cuboid-shaped. Sintered expanded glass granules have a very high degree of absorption in the range α = 0.8-1.0. However, other high absorbency materials may be used. In a modified embodiment, the strip-shaped sound absorber elements extend in a cross shape relative to one another, so that a grid is formed.

For the connection between the optionally provided carrier layer and the cover layer other auxiliary and connecting means can be used in addition to the already mentioned adhesive bond, in particular retaining clips, frame members or mechanical fasteners, as are known in the art.

According to a preferred embodiment, the volume fraction of the included sound absorber elements is between 10% and 45% of the total volume of the cover layer. Since the cover layer consists of mechanically stable, albeit also poorly sound-absorbing material, the small proportion of the more expensive, highly absorbent material of the sound absorber elements has a favorable effect on the overall cost of the sound-absorbing component. It has also been found that excellent overall absorption values can be achieved with the stated volume ratio, in particular, a sound-absorbing power increase occurs in the low-frequency range <500 Hz.

In an advantageous embodiment of the device according to the invention, the sound absorber elements have an absorption coefficient α _S = 0.7 - 1 and the cover layer instead has an absorption coefficient α _D = 0.3-0.65. Depending on the selected geometry, total absorption values α _G = 0.85-0.95 can be achieved with these values for the entire sound-absorbing component.

The cover layer is preferably made of hovwerksporigem material, in particular hovwerksporigem concrete. Modified embodiments may use other less sound-absorbing materials. The topcoat may be attached to her Sound source-oriented surface or have a profiling, if this is useful for the particular application. High overall absorption values can also be achieved with a flat surface.

As far as the sound absorber element has said frame member, this is preferably made of sheet steel with a thickness <1 mm or other hard material, eg. As plastic or fiber cement. The frame element can be formed, for example, as a U-shaped profile, so that the sound absorber element is inserted into this profile. The frame element preferably extends completely in the cover layer. Surprisingly, it has been shown that increased absorption results are achieved even if the open absorption surface not covered by the frame element is arranged away from the sound source in the cover layer. Particularly preferably, the sound absorber element is arranged with the frame element in the cover layer such that it is surrounded on all sides by the cover layer.

The possibly provided carrier layer particularly preferably consists of non-sound-absorbing material with high load-bearing capacity, for example normal concrete. However, materials with a low degree of absorption are also suitable for the carrier layer in modified embodiments.

Using the sound-absorbing components described, the present invention also proposes a soundproof wall, which is characterized in that it has a carrier layer, on which a plurality of sound-absorbing components according to the invention is mounted. In a conventional manner, support structures for mounting and / or connection of the individual sound-absorbing components are used.

A preferred embodiment of such a soundproofing wall is further distinguished by the fact that the carrier layer additionally has sound absorber elements embedded therein, which have an increased degree of absorption relative to the covering layer. The further sound absorber elements are arranged in the carrier layer in such a way that their surface facing the cover layer lies in the boundary plane between the cover layer and the carrier layer. In turn, diffraction edges are available at the transition between the highly absorbent material and the non-absorbent or only poorly absorbent material of the carrier layer, which support the interface effects described above.

In a preferred embodiment, the sound absorbing elements extend about 50% to 80% into the depth of the surrounding material of the carrier layer or the cover layer. The cover layer preferably has a thickness between 5-6 cm. A connection of the sound-absorbing component with a carrier layer for the construction of a soundproof wall preferably has a total thickness between 8 and 12 cm.

Fig. 1:

eine Querschnittsansicht einer ersten Ausführungsform eines schallabsorbierenden Bauelements mit einer Deckschicht;

Fig. 2:

eine Schnittansicht parallel zu einer ebenen Fläche des schallabsorbierenden Bauelements;

Fig. 3:

eine Querschnittsansicht einer zweiten Ausführungsform des schallabsorbierenden Bauelements mit einem weiteren Schallabsorberelement in einer Trägerschicht;

Fig. 4:

eine Querschnittsansicht einer dritten Ausführungsform des schallabsorbierenden Bauelements mit Schallabsorberelementen, die sich in der Trägerschicht und der Deckschicht erstrecken;

Fig. 5:

eine Querschnittsansicht einer vierten Ausführungsform des schallabsorbierenden Bauelements mit Schallabsorberelementen in der Trägerschicht;

Fig. 6:

eine Querschnittsansicht einer Ausführungsform des erfindungsgemäßen schallabsorbierenden Bauelements mit verschiedenen Schallabsorberelementen, die mit Rahmenelementen ausgerüstet sind;

Fig. 7:

eine Querschnittsansicht weiterer Ausführungsform des schallabsorbierenden Bauelements mit weiteren Schallabsorberelementen, die mit Rahmenelementen ausgerüstet sind;

Fig. 8:

eine Querschnittsansicht nochmals weiterer Ausführungsform des schallabsorbierenden Bauelements mit weiteren Schallabsorberelementen, die mit Rahmenelementen ausgerüstet sind.

Further advantages, details and developments of the present invention will become apparent from the following description of preferred embodiments, with reference to the drawings. Show it:

Fig. 1:

a cross-sectional view of a first embodiment of a sound-absorbing device with a cover layer;

Fig. 2:

a sectional view parallel to a flat surface of the sound-absorbing component;

3:

a cross-sectional view of a second embodiment of the sound-absorbing component with a further sound absorbing element in a carrier layer;

4:

a cross-sectional view of a third embodiment of the sound-absorbing device with sound absorber elements extending in the support layer and the cover layer;

Fig. 5:

a cross-sectional view of a fourth embodiment of the sound-absorbing device with sound absorber elements in the carrier layer;

Fig. 6:

a cross-sectional view of an embodiment of the sound-absorbing device according to the invention with different sound absorbing elements, which are equipped with frame members;

Fig. 7:

a cross-sectional view of another embodiment of the sound-absorbing device with further sound absorbing elements, which are equipped with frame members;

Fig. 8:

a cross-sectional view of yet another embodiment of the sound-absorbing component with further sound absorbing elements, which are equipped with frame elements.

In Fig. 1 a first embodiment of a sound-absorbing component is shown in a simplified cross-sectional view. In this embodiment, the sound-absorbing component, a cover layer 03 of a weak sound-absorbing material with an absorbance α _D = 0.3 - 0.65. The cover layer 03 is formed over the entire surface and in practice, for example, has a thickness of 50 mm. In the less sound-absorbing cover layer 03 a plurality of sound absorber elements 06 are made of highly absorbent material, which have an absorbance α _S = 0.7 - 1. The sound absorber elements 06 are designed, for example, as elongated strips with a cross section of 50 mm × 25 mm. Based on the total volume of the sound-absorbing material used in the component, for example, the sound absorber elements 06 have a volume fraction of 20%, while the less well-absorbing cover layer 03 comprises a volume fraction of 80%.

The sound absorber elements consist in particular of a sintered expanded glass granulate, as supplied for example by the company Liaver GmbH & Co. KG under the brand name Reapor.

In a practical embodiment, the sound absorber elements have a cross section of 50 mm x 25 mm, an absorption coefficient α _S = 0.95 and a volume fraction of the total sound-absorbing material of 20%. Preferably, the sound absorbing elements at a width of 50 mm at a distance of 200 mm from each other (or the distance between the center axes of the sound absorber elements is about 250 mm). The less sound-absorbing cover layer 03 is formed in this example over its entire surface with a flat surface and a thickness of 50 mm. It represents a volume fraction of 80% of the total sound-absorbing material of the component and has an absorption coefficient α _D = 0.5.

At the bottom of the cover layer, a fabric layer 05 is attached in the illustrated embodiment, which is sound permeable and the sound absorber elements 06 at least partially covered.

Fig. 2 shows the sound-absorbing component in a section parallel to the surface. It can be seen that the sound absorber elements 06 extend in the form of strips in the material of the cover layer 03.

Fig. 3 shows a modified embodiment in cross section. The cover layer 03 is in this case connected to a carrier layer 02. In the carrier layer 02 further sound absorbing elements 06a are embedded. The carrier layer consists of a non-absorbent material, preferably normal concrete. Between the carrier layer 02 and the cover layer 03, a boundary plane 04 is formed, to which the adjacent layers can be connected, for example by an adhesive. In addition to the sound absorber elements 06 arranged in the cover layer 02, there is another sound absorber element 06a within the carrier layer 03. The further sound absorber element 06a can consist of the same material as the sound absorber elements 06 and have the same dimensions. The further sound absorber element 06a is preferably introduced with its entire cross section in the carrier layer 02, so that its upper side facing the cover layer 03 lies in the boundary plane 04 and is preferably not covered by the material of the carrier layer.

By the arrangement, how they look Fig. 3 can be seen, results using the above Absorption values of the cover layer and the sound absorber elements has a total absorption value of α _G = 0.85.

This surprisingly high total absorption value arises due to the specific arrangement of the sound absorber elements, which are embedded in the cover layer 03 and the carrier layer 02, that of sound waves (indicated by the arrows 07), as far as they penetrate the cover layer 03, a share of numerous diffraction edges 08 impinges and there undergoes a phase shift by diffraction. The phases shifted sound waves are superimposed with the sound waves that have penetrated the cover layer 03 and optionally reflected on the support layer 02, so that there is a partial erasure. In addition, further interface effects may occur.

The diffraction edges 08 run along the lines of contact between the non-absorbing or only poorly sound-absorbing material of the carrier layer 02 or the cover layer 03 and the very sound-absorbing material of the sound absorber elements 06, 06a. It is also essential for the occurrence of the partial erasure that the sound absorber elements 06 have a predetermined distance from one another, which preferably measures a multiple of their own width. For certain applications, an optimal distance of the sound absorber elements can be calculated taking into account the wavelengths of the sound waves occurring, for example, four times the width of the sound absorber elements.

At the in Fig. 3 In the embodiment shown, the diffraction edges 08 extend in the boundary plane 04, since the sound absorber elements 06 are embedded in the cover layer 03 over their entire cross section, so that the support layer 02 facing surface of the sound absorber elements 06 in the boundary plane 04 is located. Regardless of the described effect of the diffraction and the partial erasure, the sound absorber elements 06 act in a conventional manner by sound absorption of the sound waves impinging directly on them.

The less well sound-absorbing cover layer 03 consists, for example, of cement-bound, resin-bound or water-glass bonded material, these materials being added to typical lightweight aggregates, for example expanded clay, expanded slate, expanded glass, pumice, wood chips. In mechanically under-stressed or protected by other structural designs embodiments, the cover layer may also be made of foam.

A further modified embodiment is in cross-section in FIG Fig. 4 shown. There, sound absorber elements 06b are used, which extend in cross-section both in the carrier layer 02 and in the cover layer 03. The individual sound absorber elements 06b may be formed integrally or be designed as two separate elements, the z. B. in the border plane 04 abut each other.

In Fig. 5 another embodiment of the sound-absorbing component is shown in a simplified cross-sectional view. In this embodiment, which is particularly suitable for sound absorption in the low-frequency range, the sound-absorbing component comprises the support layer 02 and the cover layer 03 connected thereto. The support layer 02 consists of a non-absorbing or poorly absorbing, ie sound-reflecting, material, for example normal concrete. The cover layer 03 consists of a weak sound-absorbing material with a Absorbance α _D = 0.3-0.65. The cover layer 03 is here formed over the entire surface and in practice has, for example, a thickness of 50 mm. Between the carrier layer 02 and the cover layer 03, the boundary plane 04 is formed, to which the adjacent layers can be connected for example by an adhesive. In this embodiment, a plurality of sound absorber elements 06 made of highly absorbent material, which have an absorption coefficient α _S = 0.7 to 1, are embedded in the non-absorbing or poorly sound-absorbing carrier layer 02. The sound absorber elements 06 are also designed here, for example, as elongated strips with a cross section of 50 mm x 25 mm. The sound absorber elements consist in particular of a sintered expanded glass granules.

Further modifications, which are not shown in the drawings, are characterized in that the carrier layer 02 has to some extent sound-absorbing properties. Likewise, it is possible to provide, adjacent to the carrier layer 02, a further mechanical carrier which may be designed as a frame or as a plate in order to support the sound-absorbing component.

In the FIGS. 6, 7 and 8 Further embodiments of the sound-absorbing component are shown in cross-sectional view, wherein various sound absorber elements 06 are shown at different positions in the cover layer 03 and / or the support layer 02 only to illustrate the possible construction variants. An essential change to the previously explained embodiments is that the sound absorber elements 06 are each equipped with one or more frame elements 10. The frame member 10 consists of a sound-reflecting Material, such as thin sheet metal, plastic or the like and covers or frames the sound absorber element 06 on at least one side, preferably on three sides. As a result, diffraction edges 08 are produced at the interfaces between sound absorber element 06 and frame element 10, the difference in the absorption coefficient of the adjacent materials being particularly high, so that the diffraction and extinguishing effect used by the invention occurs particularly strongly.

The frame elements 10 leave at least one sound-open absorption surface of the sound absorber elements uncovered or partially uncovered. The absorption surface may or may not be directed towards the sound source. The sound absorber elements 06 and the formed diffraction edges 08 are also acoustically very absorbent effect when the sound waves reflected on the hard support layer 02 impinge on these diffraction edges 08.

In the Fig. 6 to 8 are exemplified different designs of equipped with frame elements sound absorber elements. A third sound absorber element 06c extends partially in the cover layer 03 and partially in the carrier layer 02, wherein the frame elements 10 each extend on the side surfaces of the sound absorber element, are L-shaped and extend only in the cover layer. A fourth sound absorber element 06d extends completely in the cover layer 03, extends in a U-shaped frame element 10 and directs its open absorption surface in the direction of the cover layer surface, which faces the sound source. A fifth sound absorber element 06e extends completely in the cover layer 03 in a U-shaped frame element 10, which lateral holding surfaces 11, wherein a completely open absorption surface in the direction of the cover layer surface, which faces the sound source, extends and a partially opened absorption surface is formed opposite by perforation of the frame member. The holder surfaces 11 serve both the mechanical support of the frame member and as further reflection surfaces for the sound waves. A sixth sound absorber element 06f extends completely in the cover layer 03 in a U-shaped frame element 10, wherein a completely open absorption surface is directed in the direction of the sound source facing away from the cover layer surface. A seventh sound absorber element 06g extends completely in the cover layer 03 in a U-shaped frame element 10 with holding surfaces 11, wherein the bottom side of the frame element lies substantially in a plane with the sound source-facing surface of the cover layer. An eighth sound absorber element 06h extends completely in the cover layer 03 in a box-shaped frame element 10, only on the sound source side facing away from the frame member, a slot-shaped opening is provided which releases the absorption surface. A ninth sound absorber element 06i likewise extends in a box-shaped frame element 10 with only a slot-shaped opening on the side facing away from the sound source, wherein the sound absorber element only partially fills the frame element while leaving an air space.

Particularly preferably, the cover layer 03 has a thickness of 50 to 200 mm, with thicknesses of about 50 to 60 mm is well suited for the production of absorption plates, which are subsequently attached to existing walls or the like, while thicknesses of 100 to 200 mm for the construction of noise barriers are particularly suitable. If the open Absorptive surface of the sound absorber elements is directed to the back of the cover layer (the sound source side facing away), the distance a to the sound-reflecting support layer should be: at least 15 mm, with a cover layer thickness of about 60 mm; as well as at least 50 mm with a cover layer thickness of approx. 150 mm.

The frame elements are also preferably used to attach the sound absorber elements in the cover layer and / or the support layer. For this purpose, the frame members 10 may have angled retaining surfaces 11 which are embedded or anchored in the material of the cover layer 03. The frame members may be U-shaped profiles, in which strip-shaped sound absorber elements 06 are inserted. While the frame elements 10 preferably extend completely in the cover layer 03, the sound absorber elements 06 may extend in this embodiment either completely in the cover layer 03 or partially in the support layer 02, as in Fig. 6 is shown in the two variants shown on the left.

With the sound-absorbing components according to the invention can be built different applications. A preferred application is a sound barrier, which is composed of numerous sound-absorbing components.

Likewise, sound-absorbing components for sound absorption in vehicles, ships or aircraft can be used. The sound-absorbing components may be specially shaped for this, for example to follow the contours in bodies.

LIST OF REFERENCE NUMBERS

01 -

-

02 -

backing

03 -

topcoat

04 -

boundary plane

05 -

tissue layer

06 -

Sound absorber elements

06a - 06i -

Sound absorber elements

07 -

sound waves

08 -

diffraction edges

09 -

-

10 -

frame element

11 -

holding surfaces

Claims (13)

1. Sound-absorbing structural component, in particular for outdoor use, comprising a sound-absorbing cover layer (03) as well as sound-absorbing elements (06) embedded therein with an increased degree of absorption compared with the cover layer (03), wherein the surface of the cover layer facing in the direction of the sound source is designed flat, wherein the sound absorbing elements (06) are fully or partially embedded in the cover layer (03) and are arranged spaced with regard to each other, wherein an absorption surface of the sound-absorbing elements lies in a plane parallel to the cover layer, wherein in this plane the surface taken up by the sound-absorbing elements (06) is smaller than the area not taken up by sound-absorbing elements, characterised in that sound-absorbing elements (06) with an increased degree of absorption also comprise a frame element (10) which is made of a sound-reflecting material and frames the sound-absorbing element (06) on one or more sides, wherein at least the absorption surface remains open to sound.
2. Sound-absorbing structural element according to claim 1 characterised in that one side of the sound-absorbing elements (06) lies in the plane of the surface of the cover layer (03) facing away from the sound source.
3. Sound-absorbing structural element according to claim 1 or 2 characterised in that the frame element (10) is designed as a U-shaped profile into which a strip-shaped sound-absorbing element (06) is inserted.
4. Sound-absorbing structural element according to any one of claims 1 to 3 characterised in that the frame element (10) and the sound-absorbing element (06) inserted therein are surrounded on all sides by the material of the cover layer (03).
5. Sound-absorbing structural element according to any one of claims 1 to 4 characterised in that the frame element (10) has at least one perforated surface which is arranged on the side of the cover layer facing the sound source and/or facing away from the sound source in order to expose a partially open absorption surface.
6. Sound-absorbing structural element according to any one of claims 1 to 5 characterised in that the sound-absorbing cover layer (03) has a degree of absorption of α_D = 0.3 to 0.75 and the sound-absorbing elements (06) has a degree of absorption of α_S = 0.8 to 1.
7. Sound-absorbing structural element according to any one of claims 1 to 6 characterised in that the volume portion of the sound-absorbing elements (06) embedded in the cover layer (03) is between 10% and 45% of the entire volume of the cover layer.
8. Sound-absorbing structural element according to any one of claims 1 to 7 characterised in that the cover layer (03) is made of a porous material.
9. Sound-absorbing structural element according to any one of claims 1 to 8 characterised in the sound-absorbing elements (06) are made of sintered expanded glass granulate and are preferably designed to be strip-shaped or cuboid.
10. Sound-absorbing structural element according to claim 9 characterised in that the sound-absorbing elements (06) in the surface of the cover layer (03) facing away from the sound source take up an area of 20% and a depth of 50% to 80% of the thickness of the cover layer.
11. Sound-absorbing structural element according to any one of claims 1 to 10 characterised in that with its surface facing away from the sound source it can be applied to a supporting layer (02), preferably by means of one or more of the connection means selected from the following list:

    - an adhesive layer;

    - retaining clips, which grasp the supporting layer and cover layer;

    - frame elements into which the supporting layer and cover layer are inserted;

    - mechanical connection elements extending between the supporting layer and the cover layer.
12. Sound-absorbing wall with a supporting layer (02) characterised in that on the supporting layer (02) numerous sound-absorbing structural elements according to any one of claims 1 to 11 are applied.
13. Sound-absorbing wall according to claim 12, characterised in that in cross-section a first group of the sound-absorbing elements (06a) are fully embedded in the supporting layer (02) and in cross-section a second group of the sound-absorbing elements (06) are fully embedded in the cover layer (03).

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