WO2007140728A1

WO2007140728A1 - The noise protection panel

Info

Publication number: WO2007140728A1
Application number: PCT/CZ2006/000055
Authority: WO
Inventors: Ivo Vanek
Original assignee: Ivo Vanek
Priority date: 2006-06-02
Filing date: 2006-09-04
Publication date: 2007-12-13
Also published as: CZ2006363A3

Abstract

The noise protection panel is a structural element of noise protection screens constructed e.g. along highways, roads, railways, airports and industrial establishments, on road and railways bridges and other suspended structures, which prevent spreading of deleterious noise resulting from motorbike, automobile, railway and air traffic and operation of industrial establishments. It consists of a hollow lamella (1) modified for fixing in the supporting structure (3) and for its horizontal setting in the screen set, whereas the hollow lamella (1) is forward at least to the source of noise along its one face area, provided with at least one perforated acoustic spoiler (5).

Description

The noise protection panel

Field of the Invention

The invention relates to the noise protection panel which is a structural element for construction of noise protection screens, particularly in the sphere of transport construction and traffic engineering.

Background of the Invention

Emission of noise and vibrations spreading from transport constructions create one of the most significant factors of the negative impact of transportation on environment . Noise intensity spreading in form of vibrations is influenced particularly by the constructional structure of layers under the surface of communications. Transmission of vibrations is absorbed best by inserted elastic layers which minimize it. Exposed new tracks and roads, particularly in urban build-up areas, are being constructed with these anti-noise layers which in result increase the comfort of their using and safety of adjacent structures . Noise spreading from the traffic by air affects particularly larger areas along communications and it may have negative impact particularly on health of inhabitants impacted by its unpermitted noise levels due to its specific spectrum. Particularly constructions of noise-protection screens belong among basic measures limiting the exposure of noise affecting the inhabitants. These are classified from the point of view of their function and are divided to two basic groups: absorbing and reflecting. From the point of view of construction they may be transparent and non-transparent, from the point of view of their material base they are concrete, wooden, and plastic or made of natural stone and other materials. The main function of reflecting noise protection screens is based in the insertion of the screen

(barrier) against the direction of noise spread and the successive deflection of noise - contrariwise would be the best. On the contrary, absorbing noise protection screens are designed to absorb the incident noise and to prevent its further spreading.

It is one part of acoustic requirements - so called sound absorption. The second part of acoustic requirements is given by the parameter which influences the quantity of noise which passes through the noise protection screen, so called air sound insulation. This parameter is being influenced particularly by basic weight of the noise protection screen. The sound absorption of noise protection screens is an important parameter which is influenced by material features of the surface forward to the source of noise. The absorption is ensured by acoustic porous absorbers (e.g. mineral wool) . With regard to the spectrum of the road and railway noise the application of porous absorber leads only to its relatively large thickness, therefore it is necessary to use more effective solution for use of materials which at the same time leads to better adaptation of the noise absorption function of the entire spectrum of the road and railway noise. This goal may be advantageously reached by application of membrane and or Helmholtz resonators which at certain frequencies reach undesirable parameters. In order to get this effect which is not only narrowband, the resonators are supplemented with acoustic porous absorbers . The result of combination of both principles is a higher level of absorption in all frequencies of road and railway noise.

Various particular noise protection wall constructions and noise protection screens are known from many patent documents, for example from the document DE-OS 42 19 946, in which there is a known wall part created by two wall concrete layers provided with holes permeable for noise, between which there is a filling consisting of 50 % of soil and 50 % of moisture absorbing materials, such as brick chipping etc. A concrete wall part according the document CZ 284240 is created similarly. On one side it is provided with a porous absorbing layer which consists of noise permeable layer, provided with holes, behind which there is a filling consisting just of loose mineral silica parts.

Noise protection walls made of wood and wooden composite material are known e.g. from the document W099/24670. Wooden noise protection walls may be provided with various noise absorbing mats. These mats represent the basic component of the noise absorption capacity; wooden constructions shall ensure, beside the auxiliary component of noise absorption, the highest air sound insulation. The entire construction must be obviously resistant against strong wind blasts and must not break down due to its own weight.

The document EP 1 149 952 further mentions a noise protection wall which consists of massive wooden boards provided with lengthwise slots open forward to the source of noise. In other patent documents there is e.g. a noise protection barrier (in document EP 1 077 446) made of panels of noise absorbing material which may be a mineral wool or glass wool. The document WO99/22075 describes a noise protection wall consisting of several layers of mineral woollen fleece with various density; or document WO01/086070 mentions construction of noise protection wall with acoustic insulating panel consisting basically of any type of wool of a suitable synthetic glassy fibre. Further a solution of the noise protection panel according to CZ PV 2003-3502 is known. It consists of noise protection acoustic construction which is, from its face side forward to the source of noise, provided with at least one profile and/or board resonant retarder created by profile lamellas which create among them lengthwise slots absorbing sound which lead to lengthwise inside chambers whereas profile lamellas are arranged into a resonant system.

The disadvantage of these more complicated constructions of noise protection panels is their considerable production and material demands and thereby their high acquisition cost.

A specific problem is construction of noise protection walls, e.g. on bridges and various suspension reinforced concrete and steel constructions, which may not be weighted down by any materials which could worsen their static safety. Also for this reason the use of above mentioned particular noise protection walls on these places is considerably problematic.

Nevertheless, the road and railway noise is more dangerous, because the higher is the place from which the noise influences the area, the larger is the impacted area, because it intervenes to areas which are very distant from the source. Therefore the transport constructions, particularly on bridges, are being very intensively closed by noise protection walls to prevent this dangerous event. Noise protection walls built for these purposes are made of e.g. transparent reflecting plastics which often cause that the reflected noise is falling from the bridge to places even several hundreds meters away. Therefore it is better to make these walls of perforated aluminium panels filled with acoustic porous absorber. The price of these panels is considerably high and also requirements for their assembly are unequally demanding .

Sumary of the Invention

The disadvantages of the current state of the technique are to a large extent removed by noise protection panel as the structural element of noise protection screens build e.g. along highways, roads, railways, airports and industrial establishments, on road and railway bridges and other suspension constructions preventing spreading of deleterious noise arising from motorbike, automobile, railway and air transport and operation of industrial establishments, according to the invention the principle of which is the fact that it is made of hollow lamella adjusted for the attachment in the supporting structure and for its horizontal arrangement in the screen system whereas the hollow lamella is placed at least on one of its face surface forward to the source of the noise, equipped by at least one perforated acoustic spoiler.

The advantage of the noise protection panel, according to the invention, is its low weight, speed and simplicity of its assembling. Layout of hollow lamellas, creating after assembly a noise protection screen, to the horizontal configuration in the supporting structure made of e.g. reinforced concrete or steel supporting posts together with firmness of the hollow lamella profile allows extension of the span of supporting posts up to 6 m which consequently reduces the cost of foundation. The screen made of noise protection panels according to the invention may be assembled without heavy mechanization therefore it - Q -

is suitable not only for bridges, but also for inaccessible places where vehicles and cranes may not get and to the heights exceeding 10 m.

At the fixing of hollow lamellas of the noise protection panel with perforated acoustic spoilers only from one its face side, the noise protection screen completed this way is one-side absorptive. At the fixing of the hollow lamellas from both face sides, the noise protection screen is two-side absorptive, always with high grade of air sound insulation. The noise protection screen made of hollow lamellas without these perforated acoustic spoilers would serve only as the noise protection reflecting screen.

Subject matter of this invention lies in the fact that the perforated acoustic spoiler is created with advantage by the face perforated wall under which the noise absorbing chambers are created. Another advantage is that also the perforated acoustic spoiler under the noise absorbing chambers is at least partially filled with acoustic porous absorber, e.g. mineral mat. Perforation of the face perforated wall may range from 5 to 50 % of its total surface. The perforated acoustic spoiler partially or totally filled with acoustic porous absorber or even not filled creates after the fixing on the hollow lamella a set of Helmholtz resonators tuned for absorbing of normalized spectrum of road and railway noise.

The individual hollow lamellas or the noise protection screen made of them may be provided with perforated acoustic spoiler at the assembly or additionally, on one side, on the other side or on both sides. The perforated acoustic spoiler also functions as the self-locking lock of hollow lamellas in noise protection wall screen of adjacent noise protection panels. The hollow lamella in the advantageous construction of noise protection panel according to the invention is created by extruded recycled or with new plastic whereas for its horizontal arrangement in the screen set it is also provided with advantageous interlocking locks on its sides.

In case of requirement for extremely high sound insulation the inside space of the hollow lamella is filled with sound insulating filling usually made of stabilized compact construction material. It may be e.g. low-solid concrete, but also artificial geopolymer-based stone whereas the sound insulating filling may be created as a monolith cast to the inner space of the hollow lamella or as prefabricate. Basic weight is then so high that it corresponds with the air sound insulation c. 40 dB. And this is the level exceeding even the highest requirements of acousticians and hygienic officers .

It is possible to construct of the noise protection panel according the invention a non-conducting noise protection screen considering the fact that it may be completely created of non-conducting materials and that its horizontal arrangement in the noise protection screen does not require, unlike at the vertical arrangement, use of any further usually metal bolts. Therefore it is possible to build these noise protection screens also along electrified railway lines and near traction mains.

The noise protection panel according to the invention in its complex version fulfils the highest requirements for noise protection screens which shall protect nature and health of people against one of the most dangerous invisible impact of civilization and effectively liquidates dangerous waste in the environment which is noise. Brief description of the Drawings

The invention shall be explained in more details by means of drawings of concrete example of realization of the noise protection panel according to the invention which demonstrates:

Fig. 1 - cross section through scheme of noise protection panel

Fig. 2 - set of two connected noise protection panels in the dimensional image

Fig. 3 - dimensional image of part of noise protection screen

Description of the Preferred Embodiment

The noise protection panel, according to the Fig. 1, Fig. 2 and Fig. 3 consists of hollow lamella 1 with rectangular profile filled with noise protection filling 6. of geopolymer material, in this case it is cast to the inside space of the hollow lamella JL. The hollow lamella 1 is provided on one its face area forward to the source of noise with perforated acoustic spoiler 5..

The perforated acoustic spoiler 5_. consists of the face perforated wall 8_. perforation of which is created by holes the total area of which crates 15 % of the total area of the face perforated wall .8. Noise absorbing chambers 9. are created under the face perforated wall and under them there is the remaining space of the perforated acoustic spoiler 5_ filled with acoustic porous absorber 4, in this case it is mineral mat. The hollow lamella 1_. is adjusted for fixing in the supporting structure 3. created here by vertical supporting poles and for its horizontal arrangement in the vertical screen set while it is completely created by extruded recycled plastic provided with stabilizers against UV radiation. For its horizontal arrangement in the vertical screen set the hollow lamella 1 is provided on its bottom and upper horizontal area with connecting locks 2_. in the shape of mutually interlocking triangular areas. Outside areas of noise protection panel are then provided with antireflection colour-fast coat.

The Fig. 1 shows option of connection of perforated acoustic spoiler 5_. also to the other vertical side area of hollow lamella 1 by means of its insetting to mounting cannels Z-

Field of the Application

Except already mentioned options of use the noise protection panel according to the invention it may be used also for noise protection facing of buildings and for reduction of noise burden in closed spaces, e.g. in factory halls.

Claims

P AT E N T C L A I M S

1. The noise protection panel, as the structural element of noise protection screens built e.g. along highways, roads , railways, airports and industrial establishments_r on road and railways bridges and other suspended constructions preventing spreading of deleterious noise resulting from motorbike, automobile, railway and air traffic and operation of industrial establishments, characterized by the fact, that a hollow lamella (1) is modified for fixing in the supporting structure (3) and for its horizontal setting in the screen set, whereas the hollow lamella (1) is forward at least to the source of noise along its one face area, provided with at least one perforated acoustic spoiler (5) .

2. The noise protection panel according to the claim 1, characterized by the fact, that the perforated acoustic spoiler (5) is created by face perforated wall (8) under which the noise absorbing chambers (9) are created.

3. The noise protection panel according to the claim 2, characterized by the fact, that the perforated acoustic spoiler (5) under the noise absorbing chambers (9) is filled at least partially with acoustic porous absorber (4) .

4. The noise protection panel according to the claims 2, characterized by the fact, that the perforation of the face perforated wall (8) ranges from 5 to 50 % of its total area .

5. The noise protection panel according to the claim 1, characterized, by the fact, that the hollow lamella (1) is created by extruded plastic.

6. The noise protection panel according to the claim 1, characterized by the fact, that the hollow lamella (1) is provided with connecting locks (2) on its side parts for its horizontal arrangement in the screen set.

7. The noise protection panel according to at least one of the previous claims, characterized by the fact, that the inner space of the hollow lamella (1) is filled with noise protection filling (6) .

8. The noise protection panel according to the claim 7, characterized by the fact, that the noise protection filling (6) is made of a geopolymer material.

9. The noise protection panel according to the claim 8 , characterized by the fact, that the noise protection filling (6) made of geopolymer material is made of monolith cast to the inner space of the hollow lamella

(1).

10. The noise protection panel according to the claim 8, characterized by the fact, that the noise protection filling (6) made of geopolymer material is made as prefabricate .