EP0385087A2 - Sound absorbing and insulating barrier - Google Patents

Abstract

The invention relates to a barrier wall as is used along motorways or railway lines. It is formed from several sound-absorbing elements (4) disposed obliquely inside retention sections (1) and provided with a solid panel (5) forming the rear covering of the barrier wall. For the purpose of improving above all the acoustic absorption and insulation effectiveness, the invention is characterised in that the sound-absorbing elements (4) made from fibres bonded together are self-supporting in that at least two faces of these elements are clad with a water-impermeable and elastic rubbery layer, and in that the absorbing surface is greater than the plane surface of the barrier wall. <IMAGE>

Description

The invention relates to a high absorption and sound insulation wall, made up of several sound absorbing elements arranged obliquely in retaining profiles and of a solid panel forming the rear covering of the high absorption and sound insulation wall.

Such walls are particularly intended to be established along traffic routes with heavy traffic or railway tracks or any other location requiring noise protection. They are therefore used, for example, also for soundproofing particularly noisy buildings or workstations in factories and shooting ranges.

To establish such walls, for example along motorways, they must resist the effects of wind, weather, ultra-violet rays and other aggressive influences, for example the frequent chemical fallout in industrial agglomerations or salt from road salting or from all kinds of projectiles. It is therefore essentially necessary that, apart from their primary function of absorption and sound insulation, these noise-reduction walls have sufficient stability and that they are resistant to physical, chemical and mechanical attack.

With Swiss patent no. 608 537 such a noise barrier is published. It is revealed there that sound absorbing or damping elements are proposed in the form of a sound absorbing material placed in a sheet metal envelope open preferably towards the noise source, the opening being protected by a perforated sheet or by expanded metal.

In patent application GB 2 157 337 A concerning a similar noise barrier, it is provided that a waterproof sheet, preferably made of polyester, is housed in a detached manner between the active absorption element and the perforated protective sheet. .

The present invention is based on the noise barriers mentioned. However, they have various drawbacks. Thus it is almost impossible or at least very expensive, to maintain this kind of noise barriers since dust or fallout from rain or sprays caused by cars passing nearby, accumulate between the element sound absorption and perforated protective sheet.

On the other hand, the perforated protective sheets being relatively rigid, are easily damaged or cause ricochets if a hard object strikes them and prove to be quite dangerous in the event of collisions. The cost of replacing these damaged noise barriers is considerable.

In addition, this kind of protection made of sheet metal or any other rigid perforated material considerably limits the absorbent surface, since the perforations generally only represent around 50-75% of the surface of these protections and therefore minus 25% of the sounds ricochet off the rest of the surface.

• a) les éléments absorbant les sons en fibres encollés, sont autoportants;
• b) les éléments absorbant les sons sont revêtus au moins sur deux faces d'une couche caoutchouteuse imperméable à l'eau et élastique;
• c) la surface absorbante est plus grande, que la surface plane de la paroi.

The task of the invention is to improve such a noise barrier essentially with respect to sound absorption and insulation as well as to reduce to the minimum the other drawbacks mentioned. This task is solved by the characteristics cited initially combined with the following additional characteristics:

• a) the sound absorbing elements made of glued fibers are self-supporting;
• b) the sound absorbing elements are coated on at least two sides with a rubbery waterproof and elastic layer;
• c) the absorbent surface is larger than the flat surface of the wall.

The essence of the invention therefore consists in coating a rubbery waterproof and elastic layer of sound absorbing elements made of bonded fibers and that these elements are self-supporting, thus avoiding any mechanical reinforcement, such as for example. envelopes in a rigid material or the mounting of intermediate supports, even if the sound absorbing elements are arranged horizontally.

By stacking at an angle of 30 to 80 degrees, the sound absorbing elements constitute a surface with ribs and grooves, which considerably increases the absorbent surface, to the point that the absorbent surface becomes larger, than the flat surface of the wall. It also follows that, depending on the angles of impact of the sounds which are not or only partially absorbed, these sounds are returned one or more times while creating interference, which disturbs the propagation of the sound waves.

The sound absorbing elements stacked at an angle and provided with a rubbery waterproof and elastic layer, these elements become sufficiently resistant that any use of rigid protections on the side of the noise source is superfluous. It follows that by their direct exposure to the weather, a free natural washing of their surfaces exposed to dirt is provided, thus automatically evacuating the dust and chemical fallout, which could be deposited on the sound absorbing elements.

The use of sound absorbing elements without protective mesh is also requested for aesthetic reasons. The invention can all the more satisfy these kinds of requirements, as in addition the rubber layer can be tinted according to particular needs. The elasticity of the waterproof rubber layer also helps absorb the impact of any hard object that could strike the sound absorbing elements. It follows that eg stones thrown by cars against these walls, generally do not cause any damage and that the risks in the event of a collision are considerably reduced.

It is particularly advantageous to use plates of mineral fibers compressed and glued with synthetic resin or melamine as sound absorbing elements, which by this constitution and in addition to their excellent sound absorption qualification, resistance optimal mechanics.

Their consistency is preferably such that the sound absorbing elements are, in the direction of their length, slightly compressible, so that they can be mounted by wedging between two retaining profiles, which makes the assembly of parts unnecessary. support to the retaining profiles, even if the sound absorbing elements are mounted horizontally. It is also advantageous if the same compressibility of these sound absorbing elements is also given in the direction of their width, so that the impact damping of hard objects corresponds to that of the elastic rubbery layer.

The waterproof rubber layer advantageously has an elasticity of more than 300% without any tearing being observed, which guarantees the sound absorption efficiency of the sound absorbing element and the watertightness of the material. water. To achieve these qualities and also to resist momentary overloads in the event of shock, the rubber layer preferably has a thickness of at least 0.5 millimeter.

For the stacking of sound absorbing elements, provision is made to use U-shaped or double T-shaped retaining profiles, which themselves are individually anchored or which are previously assembled in a frame, on the ground or on a base. or on any other fixing base, by appropriate means (bolts, studs, etc.). The solid panel also attaches to these same retaining sections, forming the rear covering of the wall. Without this being necessary, it may be useful to provide a support between the wings of the retaining profile, for example in the form of a square, fixing the inclination of the first stacked sound absorbing element.

Other characteristics of the invention form part of additional claims and will be specified with other advantages of the invention in the description of the exemplary embodiments.

• Fig. 1 une paroi à haute absorption et isolation phonique verticale, en coupe verticale;
• Fig. 2 la zone inférieure de l'exemple d'exécution selon <Fig. 1, en coupe verticale agrandie;
• Fig. 3 le profilé de retenue de l'exemple d'exécution selon Fig. 1, en coupe horizontale;
• Fig. 4 la coupe verticale du détail selon Fig. 2 d'une exé­cution modifiée;
• Fig. 5 la coupe verticale du détail selon Fig. 2 d'une autre exécution modifiée;
• Fig. 6 des éléments absorbant les sons 4, vue en coupe, avec des formes alternatives;
• Fig. 7 des éléments absorbant les sons 4, vue en coupe, basés sur la forme d'un parallélogramme.

The drawings represent some examples of execution of the invention. They show:

• Fig. 1 a wall with high absorption and vertical sound insulation, in vertical section;
• Fig. 2 the lower zone of the example of execution according to <Fig. 1, in enlarged vertical section;
• Fig. 3 the retaining profile of the exemplary embodiment according to FIG. 1, in horizontal section;
• Fig. 4 the vertical section of the detail according to FIG. 2 of a modified execution;
• Fig. 5 the vertical section of the detail according to FIG. 2 of another modified execution;
• Fig. 6 sound absorbing elements 4, sectional view, with alternative shapes;
• Fig. 7 of the sound absorbing elements 4, sectional view, based on the shape of a parallelogram.

Figures 1 and 2 show the essential parts of an embodiment according to the invention. This wall consists of vertical retaining sections 1, U-shaped or double Tee, between the wings 2 and 3 from which the sound absorbing elements 4 are stacked obliquely. On the wings 3, opposite the noise source, retaining profiles 1, the covering panel 5 is fixed, forming the rear of the wall, which is advantageously provided in a heavy material which is difficult to vibrate. The retaining sections 1 are anchored for example to the ground or to a base by means of appropriate fasteners 6.

An execution with 4 sound absorbing elements arranged vertically between the retaining profiles 1 placed horizontally, is not drawn, but consists of the same essential parts. The sound absorbing elements 4, which, when viewed in cross section, preferably have an approximately rectangular or parallelogram shape, are provided at least on the two faces exposed directly to the weather with a rubber layer 7 impermeable to the water and elastic. In the execution example shown in FIG. 2, the sound absorbing elements 4 are stacked at an angle of about 60 degrees relative to the vertical plane of the wall. This angle can however vary between 30 and 80 degrees. In the same figure there is shown a square 8, preferably mounted in the factory, which can facilitate assembly on site, by imposing the desired inclination when mounting the first sound absorbing element 4.

If a noise barrier only has an absorbent surface, the use of U-shaped retaining profiles 1 is recommended. If, however, such a wall has several absorbent surfaces, preference may be given to the use of retaining profiles 1 in the form of a double Tee at the point where two absorbent surfaces join. Figure 3 shows an example of this execution.

Taking into account the compressibility in length of the sound absorbing elements 4, the distance a between two retaining sections 1 is slightly smaller, than the initial length b of the sound absorbing elements 4, which once assembled, hold by wedging between the retaining profiles 1.

When such a wall is mounted on a shooting range, it may be indicated to provide a covering 9, for example of wood, on the wings 2 of the retaining profile 1, in order to protect against possible ricochets of bullets.

If such walls are exposed to strong wind turbulence, as may be the case for example in aircraft parking spaces, or if it is desired to space two retaining profiles 1 extremely apart, it may be useful to place one or more several rods 10, passing vertically through the sound absorbing elements 4, between the retaining sections 1.

Figure 4 shows an example of a special execution improving the absorption of high frequency sounds. For this purpose it is advantageous to space in parallel each sound absorbing element 4 of the following. The spacing can be achieved without accessories, since the sound absorbing elements 4 can be positioned by wedging. However, the local use of spacers 11 can be advised to facilitate rapid positioning and assembly. This special solution provides an angle of inclination of the sound absorbing elements 4 of about 45 degrees relative to the flat surface of the wall. It is also advantageous to place additional sound insulation 12 over the entire interior surface of the covering panel 5 forming the rear of the wall.

FIG. 5 shows another exemplary embodiment, which advantageously is suitable as sound insulation between two opposite sources of noise, for example between two noisy machines or between two shooters in a shooting range.

The execution plans to assemble back-to-back 2 walls as shown in Figure 2. In this case, the covering panel 5 of one of the walls can be omitted.

Figure 6 shows a choice of different shapes of absorbent elements the sounds 4, which for different reasons (aesthetics, additional increase in the absorbent surface, etc.) could replace the elements either of rectangular shape or of shape of a parallelogram.

FIG. 7 shows sound absorbing elements 4 based on the shape of a parallelogram, one of the points 16 of which is removed and the face 17 coated with the layer (7) bears against the wing 2 and the face 18 coated with the layer (7) against the wing 3 of the retaining profiles 1, which prevents the tipping of the sound absorbing elements 4 even in the event of a severe storm.

Claims (15)

1. High absorption and sound insulation wall consisting of sound absorbing elements (4) stacked obliquely between retaining profiles (1) in the shape of a U or double T and a panel (5) full, forming the covering back of the wall, characterized by a) sound absorbing elements (4) made of self-supporting glued fibers; b) sound absorbing elements (4) coated on at least two faces with a rubbery layer (7) waterproof and elastic; c) an absorbent surface, which is larger, than the flat surface of the wall. 2. High absorption and sound insulation wall according to claim 1, characterized in that the sound absorbing elements (4) are stacked with a parallel space between each sound absorbing element (4); 3. High absorption and sound insulation wall according to claim 1, characterized in that several sound absorbing elements (4) are made in one piece forming a profiled plate; 4. high absorption and sound insulation wall according to claims 1 to 3, characterized in that the sound absorbing elements (4) are made of mineral fibers bonded with synthetic resin or melamine; 5. Wall with high absorption and sound insulation according to claims 1 to 4, characterized in that the rubbery waterproof and elastic layer is based on high polymers dispersed in water and has an elasticity of at least 300 % and a thickness of at least half a millimeter; 6. High absorption and sound insulation wall according to claims 1 to 5, characterized in that the sound absorbing elements (4) have hand compressibility in the direction of their length of about two percent and in the direction of their width, approximately ten percent locally and the sound absorbing elements (4) are fixed between the retaining profiles (1) by wedging; 7. high absorption and sound insulation wall according to claims 1 to 6, characterized in that the sound absorbing elements (4) are arranged with an inclination of thirty to eighty degrees relative to the vertical plane of the wall; 8. high absorption and sound insulation wall according to claims 1 to 7, characterized in that the sound absorbing elements (4) have, in cross section, an approximately rectangular shape; 9. high absorption and sound insulation wall according to claims 1 to 6, characterized in that the sound absorbing elements (4) have, in cross section, the shape of a parallelogram, one or two of the points (16 ) are suppressed and the face (17) coated with the layer (7) bears against the wing (2) and the face (18) coated with the layer (7) against the wing (3) of the retaining profiles (1); 10. High absorption and sound insulation wall according to claims 8 and 9, characterized in that a longitudinal face of the sound absorbing elements (4) has, in cross section, grooves (13), or is convex (14 ) or concave (15), or is otherwise profiled; 11. High absorption and sound insulation wall according to claims 1 to 10, characterized in that the retaining profiles (1) are anchored assembled in a frame or individually by means of fixings (6) on the ground, on a base or on any other fixing base; 12. Wall with high absorption and sound insulation according to claims 1 to 11, characterized in that the wings (2) of the retaining sections (1) are provided with a coating (9) of anti-rattle protection; 13. high absorption and sound insulation wall according to claims 1 to 12, characterized in that a complementary sound insulation (12) covering the entire inner surface of the panel (5) is placed between the latter and the sound absorbing elements (4); 14. high absorption and sound insulation wall according to claims 1 to 13, characterized in that two high absorption and sound insulation walls are assembled back-to-back and that the panel (5) of one of the two walls is removed ; 15. high absorption and sound insulation wall according to claims 1 to 14, characterized in that one or more rods (10) passing through the sound absorbing elements (4) are placed in parallel between two retaining sections (1).

Images