ACOUSTIC ATTENUATION DEVICE PROVIDED WITH INSERTS MADE OF ACOUSTICALLY ABSORBENT MATERIAL

An acoustic attenuation device having two inserts made of acoustically absorbent material, the two inserts being different from each other and being separated from each other so as to delimit between them a longitudinal slot, each insert including a front surface intended to be oriented towards a space to be acoustically attenuated; and two support elements which are made of substantially acoustically impermeable material and which at least partially delimit an internal cavity in which the two inserts are disposed, each support element including a cover part partially covering the front surface of a respective insert such that the front surfaces of the two inserts are partially exposed, the two cover parts delimiting at least one passage opening which emerges into the internal cavity and which is located at least partially opposite the longitudinal slot so as to clear an access to the longitudinal slot.

TECHNICAL FIELD

The present disclosure concerns an acoustic attenuation device, for example for buildings.

BACKGROUND

In order to attenuate the noise in a building, it is known to place acoustic attenuation panels on the interior walls and/or the ceilings of the building.

Such acoustic attenuation panels may for example be made of polystyrene, cement concrete or even glass wool or rock wool. However, such acoustic attenuation panels have drawbacks.

Indeed, the polystyrene acoustic attenuation panels have relatively low fire resistance and recyclability and have a significant environmental impact, and the glass wool and rock wool acoustic attenuation panels also have a low recyclability. In addition, the cement concrete acoustic attenuation panels have relatively low or even zero acoustic absorption properties if not combined with porous panels with acoustic absorption properties. However, the use of porous panels may be difficult or inappropriate, especially in humid environments, such as in the swimming pools.

BRIEF SUMMARY

The present disclosure aims to remedy all or part of these drawbacks.

The technical problem underlying the present disclosure therefore consists in providing an acoustic attenuation device which is of simple and economical structure, while having improved acoustic attenuation performance.

To this end, the present disclosure concerns an acoustic attenuation device including:two inserts made of acoustically absorbent material, the two inserts being distinct from each other and being separated from each other so as to delimit a longitudinal slot between them, each insert including a front surface intended to be oriented towards a space to be acoustically attenuated, andtwo support elements which are made of substantially acoustically impermeable material and which at least partially delimit an internal cavity in which the two inserts are disposed, each support element including a cover part partially covering the front surface of a respective insert such that the front surfaces of the two inserts are partially exposed, the two cover parts delimiting at least one passage opening which emerges into the internal cavity and which is located at least partially opposite the longitudinal slot so as to clear an access to the longitudinal slot, from the outside of the acoustic attenuation device and in particular from the space to be acoustically attenuated.

The presence of the longitudinal slot between the two inserts made of acoustically absorbent material and of the at least one passage opening introduces surface irregularities at the exposed face of the acoustic attenuation device which is intended to be oriented towards the space to be acoustically attenuated.

Such surface irregularities, coupled with the presence of the two inserts made of acoustically absorbent material, respectively induce phenomena of diffraction of the sound waves coming from the space to be acoustically attenuated and phenomena of acoustic absorption of said sound waves. In addition, the presence of the longitudinal slot induces phenomena of pressure diffusion increasing the acoustic absorption at low frequencies.

Consequently, the acoustic attenuation device according to the present disclosure has improved acoustic attenuation performance compared to the acoustic attenuation devices of the prior art, and in particular a high acoustic absorption coefficient over a wide frequency range, and this while a large part of the external surfaces of the acoustic attenuation device in contact with the air, and therefore with the sound waves, is made of a substantially acoustically impermeable material. In particular, the acoustic attenuation device may attenuate the surrounding noise in a wide frequency range by adapting the dimensions of the longitudinal slot, of the cover parts and of the at least one passage opening.

In addition, such a configuration of the acoustic attenuation device according to the present disclosure makes it possible to produce a maximum of external surfaces of the acoustic attenuation device in substantially acoustically impermeable material, such as concrete or metal, and therefore to give the acoustic attenuation device a high mechanical strength.

The acoustic attenuation device may additionally have one or more of the following characteristics, taken alone or in combination.

According to one embodiment of the present disclosure, the acoustic attenuation device includes an exposed face which is intended to be oriented towards the space to be acoustically attenuated and to be located in the latter, the exposed face being partly defined by the two cover parts.

According to one embodiment of the present disclosure, the acoustic attenuation device has an acoustic absorption coefficient greater than 0.5.

According to one embodiment of the present disclosure, the internal cavity communicates with the exterior of the acoustic attenuation device through the at least one passage opening, and preferably only through the at least one passage opening.

According to one embodiment of the present disclosure, the internal cavity extends longitudinally.

According to one embodiment of the present disclosure, the internal cavity has a generally parallelepipedic shape.

According to one embodiment of the present disclosure, the two cover parts extend substantially in the same plane.

According to one embodiment of the present disclosure, each insert has a rectangular section.

According to one embodiment of the present disclosure, the at least one passage opening is elongated and extends in a direction of extension.

According to one embodiment of the present disclosure, the at least one passage opening is a passage slot which has a width greater than a width of the longitudinal slot. Such a configuration of the passage opening, coupled with the presence of an acoustically absorbent material at the rear of the passage opening, forms a resonator which further improves the acoustic performance of the acoustic attenuation device according to the present disclosure.

According to one embodiment of the present disclosure, the passage slot has a width comprised between 2 and 10 cm, and for example between 7 and 8 cm.

According to one embodiment of the present disclosure, the longitudinal slot has a width comprised between 0.5 and 1.9 cm, and for example of approximately 1 cm.

According to one embodiment of the present disclosure, the longitudinal slot is centered with respect to the passage slot.

According to one embodiment of the present disclosure, the passage slot has the same length as the internal cavity.

According to one embodiment of the present disclosure, the internal cavity has a width greater than the width of the passage slot.

According to one embodiment of the present disclosure, the passage slot is substantially parallel to the longitudinal slot.

According to one embodiment of the present disclosure, each insert is elongated and extends in a direction of extension.

According to one embodiment of the present disclosure, each insert extends substantially parallel to the longitudinal slot.

According to one embodiment of the present disclosure, each insert is made of hemp concrete.

According to another embodiment of the present disclosure, each insert could be made of mineral wool, for example glass wool or rock wool, or an acoustically absorbent foam.

According to one embodiment of the present disclosure, each cover part has a thickness less than the thickness of the respective insert.

According to one embodiment of the present disclosure, each cover part has a thickness comprised between 1 mm and 3 cm, and for example between 1 and 5 mm, and advantageously between 1 and 3 mm.

According to one embodiment of the present disclosure, each insert has a thickness comprised between 3 and 10 cm, and for example between 3.5 and 6 cm.

According to one embodiment of the present disclosure, each support element is metallic, and for example made of stainless steel.

According to one embodiment of the present disclosure, each support element is made of cement concrete, and for example of Ultra High Performance Fiber Concrete (UHPC).

According to one embodiment of the present disclosure, each support element has an angle iron shape. In other words, each support element has an L cross-section.

According to one embodiment of the present disclosure, the two support elements are distinct from each other and separated from each other.

According to one embodiment of the present disclosure, the acoustic attenuation device includes a rear wall connecting the two support elements to each other, the rear wall and the two support elements forming a box and delimiting the internal cavity in which the two inserts are disposed.

According to one embodiment of the present disclosure, the two support elements respectively form the two lateral walls of the box.

According to one embodiment of the present disclosure, the two cover parts extend substantially parallel to the rear wall.

According to one embodiment of the present disclosure, the box is elongated.

According to one embodiment of the present disclosure, the box has a generally parallelepipedal shape.

According to one embodiment of the present disclosure, the acoustic attenuation device further includes a structural layer which is made of a substantially acoustically impermeable material, the two inserts and the two support elements being fastened to, and for example at least partially integrated in, the structural layer. The fact of making the structural layer made of a substantially acoustically impermeable material gives the acoustic attenuation device significant insulation properties against the external noise. The realization of the acoustic attenuation device according to the present disclosure from a structural layer also ensures a high mechanical strength to the acoustic attenuation device.

According to one embodiment of the present disclosure, the substantially acoustically impermeable material forming the structural layer has an acoustic absorption coefficient less than 0.2.

According to one embodiment of the present disclosure, the structural layer is obtained by hardening a cementitious composition.

According to one embodiment of the present disclosure, the cementitious composition forming the structural layer includes at least one hydraulic binder.

According to one embodiment of the present disclosure, the hydraulic binder includes at least one cement chosen from a Portland cement, an aluminous cement, a sulfoaluminate cement and/or a prompt natural cement.

According to one embodiment of the present disclosure, the structural layer is made of cement concrete.

According to one embodiment of the present disclosure, the structural layer includes a first external surface and a second external surface opposite the first external surface, the first external surface being intended to be oriented towards the space to be acoustically attenuated.

According to one embodiment of the present disclosure, the structural layer has a substantially parallelepipedal shape.

According to one embodiment of the present disclosure, each insert includes a first lateral surface and a second lateral surface which is opposite to the respective first lateral surface, the first lateral surfaces of the two inserts delimiting the longitudinal slot. Advantageously, the first lateral surfaces of the two inserts are located directly opposite each other. In other words, no structural element is disposed between the first lateral surfaces of the two inserts.

According to one embodiment of the present disclosure, the cover parts extend on either side of a longitudinal plane extending between the two inserts and in the longitudinal slot, and more particularly extend longitudinally on either side of the longitudinal slot.

According to one embodiment of the present disclosure, each support element, and more particularly the cover part of each support element, extends along the respective insert.

According to one embodiment of the present disclosure, each cover part includes an internal longitudinal edge, the internal longitudinal edges of the two cover parts delimiting the at least one passage opening.

According to one embodiment of the present disclosure, each support element is elongated and extends substantially parallel to the longitudinal slot.

According to one embodiment of the present disclosure, each support element includes a fastening part fastened to the structural layer. Advantageously, each fastening part is partially integrated into the structural layer.

According to one embodiment of the present disclosure, each fastening part is secured to the structural layer during the hardening of the cementitious composition forming the structural layer.

According to one embodiment of the present disclosure, the two inserts are spaced from each other by a distance less than the width of an insert.

According to one embodiment of the present disclosure, the longitudinal slot has a width greater than one tenth of the width of the passage slot.

According to one embodiment of the present disclosure, the passage slot has a width less than twice the width of an insert.

According to one embodiment of the present disclosure, each insert is in one piece, that is to say it is made in one piece.

The present disclosure also concerns an acoustic attenuation assembly comprising a retaining element and at least two acoustic attenuating devices according to the present disclosure, each acoustic attenuating device being fastened to the retaining element.

According to one embodiment of the present disclosure, the acoustic attenuation assembly is configured to be disposed between two concrete pre-slabs. Advantageously, the acoustic attenuation assembly is configured to rest on the concrete pre-slabs.

According to one embodiment of the present disclosure, the two acoustic attenuation devices are spaced from each other and extend substantially in the same plane of extension.

According to one embodiment of the present disclosure, the acoustic attenuation assembly includes a retaining element, for example metallic, including a retaining part which is substantially planar, the support elements of the two acoustic attenuation devices being fastened to the retaining part so that the retaining part and the support elements form two boxes delimiting two internal cavities in each of which the two respective inserts are disposed.

According to one embodiment of the present disclosure, the retaining element further includes two lateral bearing parts which are configured to rest on the pre-slabs.

According to one embodiment of the present disclosure, the retaining part includes, on its face opposite the acoustic attenuation devices, anti-slip projections.

According to one embodiment of the present disclosure, the acoustic attenuation assembly includes a support part which is fastened to the retaining element, the support part including two lateral branches which respectively form the adjacent support elements of the two acoustic attenuation devices.

According to one embodiment of the present disclosure, the support part further includes a central chute which connects the two lateral branches of the support part to each other, the central chute and the retaining part delimiting a central cavity.

According to one embodiment of the present disclosure, the acoustic attenuation assembly further includes perforated cover elements which partially cover the passage openings delimited by the support elements. Advantageously, each perforated cover element is metallic, and has a perforation rate greater than 70%.

According to one embodiment of the present disclosure, each perforated cover element is fastened, preferably in a removable manner, to the cover parts of the support elements of a respective acoustic attenuation device.

According to one embodiment of the present disclosure, the acoustic attenuation assembly includes a closure plate which is removable and which delimits, with the support part, an internal chamber in which longitudinal elements, such as fluid pipes and/or electric cables, may be disposed.

The present disclosure further concerns a construction element for a building comprising a support structure and a plurality of acoustic attenuation devices according to the present disclosure, each acoustic attenuation device being fastened to the support structure.

According to one embodiment of the present disclosure, the acoustic attenuation devices are disposed substantially parallel to each other.

According to one embodiment of the present disclosure, the support structure is made of a substantially acoustically impermeable material.

According to one embodiment of the present disclosure, the substantially acoustically impermeable material forming the support structure has an acoustic absorption coefficient less than 0.2.

According to one embodiment of the present disclosure, the support structure is obtained by hardening a hardenable material.

According to one embodiment of the present disclosure, the hardenable material is a cementitious composition.

According to one embodiment of the present disclosure, the support structure is made of cement concrete.

According to one embodiment of the present disclosure, each acoustic attenuation device is at least partially embedded in the support structure before the hardening of the hardenable material forming the support structure.

According to another embodiment of the present disclosure, each acoustic attenuation device is attached to the support structure. Each acoustic attenuation device may for example be fastened to the support structure by gluing, clipping, screwing or by any other means.

According to one embodiment of the present disclosure, two adjacent acoustic attenuation devices of said plurality of acoustic attenuation devices are connected to each other by a connecting wall which partially delimits a longitudinal internal chamber.

According to one embodiment of the present disclosure, the connecting wall and the cover parts of the two adjacent acoustic attenuation devices extend substantially in the same plane.

According to one embodiment of the present disclosure, the construction element includes fluid pipes and/or electric cables extending in the longitudinal internal chamber.

According to one embodiment of the present disclosure, the support structure includes:a plurality of concrete pre-slabs spaced from each other, one or more acoustic attenuation devices being disposed between two adjacent concrete pre-slabs, anda concrete layer poured over the concrete pre-slabs and the acoustic attenuation devices so as to secure the concrete pre-slabs and the acoustic attenuation devices.

According to one embodiment of the present disclosure, the construction element includes fluid flow tubes, such as PEX tubes, positioned on the pre-slabs and embedded in the concrete layer.

According to one embodiment of the present disclosure, the construction element is intended to form at least partially a ceiling, a wall or a floor.

According to one embodiment of the present disclosure, the construction element is a pre-slab.

According to one embodiment of the present disclosure, the construction element is a slab.

DETAILED DESCRIPTION

FIGS.1and2represent an acoustic attenuation device2adapted to achieve an acoustic attenuation of the noise in a building, such as for example an individual dwelling, a collective dwelling, an office building, an agricultural or semi-agricultural building. The acoustic attenuation device2may be used both to provide an acoustic insulation for a new building or for the renovation of an old building. The acoustic attenuation device2may be fastened to a wall or a ceiling of the building, or be integrated into a ceiling of the building.

The acoustic attenuation device2advantageously has a generally parallelepipedal shape. The acoustic attenuation device2may for example have a thickness less than or equal to 0.1 m, a width less than or equal to 0.5 m, and a length less than or equal to 1.2 m.

According to the embodiment represented inFIGS.1and2, the acoustic attenuation device2comprises a structural layer3which has a substantially parallelepipedal shape and which comprises a first external surface4and a second external surface5opposite to the first surface external4. The first external surface4of the structural layer3is intended to be oriented towards a space to be acoustically attenuated.

The structural layer3is advantageously made of a substantially acoustically impermeable material which advantageously has an acoustic absorption coefficient α less than 0.2, and for example less than 0.1.

According to one embodiment of the present disclosure, the structural layer3is obtained by hardening a cementitious composition comprising in particular a hydraulic binder, at least one adjuvant, water and granulates or aggregates, such as sand. The hydraulic binder advantageously includes at least one cement chosen from a Portland cement, an aluminous cement, a sulfoaluminate cement and/or a prompt natural cement. The structural layer3may for example be made of cement concrete.

The structural layer3more particularly comprises a longitudinal groove6provided on the first external surface4.

The acoustic attenuation device2further comprises two support elements7which are made of substantially acoustically impermeable material and which are secured to the structural layer3. According to the embodiment represented inFIGS.1and2, each support element7is metallic, and for example stainless steel, and has an angle iron shape. In addition, according to the embodiment represented inFIGS.1and2, the two support elements7are distinct from each other and separated from each other.

Each support element7includes a fastening part8fastened to a respective lateral wall of the longitudinal groove6, and a cover part9which extends perpendicularly to the respective fastening part8and in the plane of extension of the first external surface4of the structural layer3. Each fastening part8may for example be partially integrated into the structural layer3, and be secured to the latter during the hardening of the cementitious composition forming the structural layer3.

The two support elements7and the structural layer3delimit an internal cavity11which extends longitudinally and which has a globally parallelepiped shape. The cover parts9of the two support elements7, and more particularly the internal longitudinal edges of the cover parts9, delimit a passage slot12which emerges into the internal cavity11and which extends over substantially the entire length of the internal cavity11. The internal cavity11has a width greater than the width of the passage slot12, and communicates with the exterior of the acoustic attenuation device2through the passage slot12.

The acoustic attenuation device2also comprises two inserts13made of acoustically absorbent material disposed in the internal cavity11. According to the embodiment represented inFIGS.1and2, each insert13is elongated and extends in a direction of extension. Advantageously, each insert13extends substantially parallel to the passage slot12. Each insert13may for example have a rectangular section.

According to one embodiment of the present disclosure, each insert13is made of hemp concrete. However, according to one variant of the present disclosure, each insert13could be made of mineral wool, for example glass wool or rock wool, or an acoustically absorbent foam.

The two inserts13are distinct from each other and are separated from each other so as to delimit between them a longitudinal slot14which is substantially parallel to the passage slot12and to the direction of extension of the inserts13. Advantageously, the longitudinal slot14is centered with respect to the passage slot12.

Advantageously, the passage slot12has a width greater than the width of the longitudinal slot14and is located opposite the longitudinal slot14so as to free an access to the longitudinal slot14.

Each insert13includes a front surface13.1intended to be oriented towards the space to be acoustically attenuated, a rear surface13.2oriented towards the bottom of the internal cavity11, a first lateral surface13.3partially delimiting the longitudinal slot14and a second lateral surface13.4oriented towards a respective fastening part8.

As shown more particularly onFIG.2, the cover part9of each support element7partially covers the front surface13.1of a respective insert13so that the front surfaces13.1of the two inserts13are partially exposed. Advantageously, each cover part9has a thickness less than the thickness of the respective insert13, and at least 15% of the front face13.1of each insert13is exposed.

According to one embodiment of the present disclosure, the passage slot12has a width comprised between 2 to 10 cm, and for example between 7 and 8 cm, and the longitudinal slot14has a width comprised between 0.5 to 1.9 cm, and for example about 1 cm or about 1.5 cm. According to one embodiment of the present disclosure, each cover part9has a thickness comprised between 1 mm and 3 cm, and for example between 1 and 5 mm, and each insert13has a thickness comprised between 3 and 10 cm, and for example between 3.5 and 6 cm. Each insert13may also have a width comprised between 3 and 8 cm, and for example between 4 and 6 cm.

As shown onFIG.3, such a configuration of the acoustic attenuation device2makes it possible to obtain an average acoustic absorption coefficient of approximately 0.7 over the frequency range 500 Hz-5000 Hz, and this for a structural layer3having a low thickness and made of cement concrete and for cover parts9of 3 mm thickness and inserts13of 5 cm thickness.

FIG.4represents an acoustic attenuation device2according to a second embodiment of the present disclosure which differs from the first embodiment essentially in that the acoustic attenuation device2include a rear wall15, for example made of substantially acoustically impermeable material, which connects the fastening parts8of the two support elements7to each other and which has a length substantially identical to that of the support elements7, and in that the rear wall15and the two support elements7form a box16of generally parallelepipedal shape and delimit the internal cavity11in which the two inserts13are disposed. Advantageously, the rear wall15and the two support elements7are made in a single piece.

According to such an embodiment of the present disclosure, the two support elements7respectively form the two lateral walls of the box16, and the two cover parts9extend substantially parallel to the rear wall15.

FIG.5represents a construction element17for a building, such as a pre-slab, comprising a support structure18made of substantially acoustically impermeable material and a plurality of acoustic attenuation devices2disposed substantially parallel to each other and conforming to a third embodiment of the present disclosure.

The substantially acoustically impermeable material forming the support structure18advantageously has an acoustic absorption coefficient less than 0.2, and for example less than 0.1. Advantageously, the support structure18is obtained by hardening a cementitious composition, and may for example be made of cement concrete.

Each acoustic attenuation device2according to the third embodiment of the present disclosure differs from the first embodiment represented inFIGS.1and2essentially in that it lacks a structural layer3. The two support elements7and the two inserts13of each acoustic attenuation device2are in particular secured to the support structure18by partially embedding them in the cementitious composition forming the support structure18before it hardens.

According to one variant of the construction element17ofFIG.5, acoustic attenuation devices2according to the first embodiment could be secured to the support structure18.

FIG.6represents a construction element17for a building, such as a pre-slab, comprising a support structure18made of substantially acoustically impermeable material and a plurality of acoustic attenuation devices2disposed substantially parallel to each other and conforming to a fourth embodiment of the present disclosure.

Each acoustic attenuation device2according to the fourth embodiment of the present disclosure differs from the second embodiment represented inFIG.4essentially in that it lacks a structural layer3.

The box16formed by the rear wall15and the two support elements7of each acoustic attenuation device2may be secured to the support structure18in different ways. The box16may for example be partially embedded in the cementitious composition forming the support structure18before it hardens, or may be attached to the support structure18and be fastened to the latter, for example by gluing, clipping, screwing or by any other mean.

According to one variant of the construction element17ofFIG.6, acoustic attenuation devices2according to the second embodiment could be secured to the support structure18.

FIG.7represents a construction element17for a building, such as a slab, comprising a support structure18made of substantially acoustically impermeable material and a plurality of acoustic attenuation devices2disposed substantially parallel to each other and conforming to a fifth embodiment of the present disclosure.

According to the embodiment represented inFIG.7, the support structure18includes:a plurality of concrete pre-slabs19spaced apart from each other, one or more acoustic attenuation devices2being disposed between two adjacent concrete pre-slabs19, anda concrete layer21poured over the concrete pre-slabs19and the acoustic attenuation devices2so as to secure the concrete pre-slabs19and the acoustic attenuation devices2.

According to such an embodiment of the present disclosure, said plurality of acoustic attenuation devices notably includes two adjacent acoustic attenuation devices2which are connected to each other by a connecting wall22. The connecting wall22advantageously extends in the plane of extension of the cover parts9of the two adjacent acoustic attenuation devices2and partially delimits a longitudinal internal chamber23in which longitudinal elements24, such as fluid pipes and/or electrical cables, may be disposed.

The construction element17represented inFIG.7further includes fluid flow tubes25, such as PEX tubes, positioned on the pre-slabs and embedded in the concrete layer21, and connecting elements26which are configured to fluidically connect the fluid flow tubes25between them and which are also positioned on the pre-slabs and embedded in the concrete layer21.

Such a configuration of the construction element17makes it possible to obtain an active slab having improved acoustic performance, while allowing an easy access to the fluid pipes and/or electrical cables disposed in the longitudinal internal chamber23when, for example, the connecting wall22is removably fastened to the adjacent acoustic attenuation devices2or when the adjacent acoustic attenuation devices2are removably fastened to the support structure18.

FIGS.8and9represent an acoustic attenuation assembly27which is configured to be disposed between two adjacent concrete pre-slabs19and which comprises two acoustic attenuation devices2conforming to a sixth embodiment of the present disclosure. Advantageously, the acoustic attenuation assembly27is configured to rest on the concrete pre-slabs19, and the two acoustic attenuation devices2are spaced from each other and extend substantially in the same plane of extension.

The acoustic attenuation assembly27includes a retaining element28which is advantageously metallic and which may for example be obtained by bending a metal sheet. The retaining element28includes a retaining part29which is substantially planar and which may for example have a rectangular shape.

The support elements7of the two acoustic attenuation devices2are fastened to the retaining part29in such a way that the retaining part29and the support elements7form two boxes16and delimit two internal cavities11in each of which the two respective inserts13are disposed. The two lateral portions of the retaining part29more particularly form two rear walls each connecting the two respective support elements7.

The retaining element28further includes two lateral bearing parts31which extend substantially parallel to one another and which are configured to rest on the pre-slabs19. The lateral bearing parts31extend more particularly from two opposite lateral edges of the retaining part29.

The retaining part29may advantageously include, on its face opposite the acoustic attenuation devices2, anti-slip projections32, such as anti-slip pads. The presence of such anti-slip projections32makes it possible to prevent a slipping, and therefore a fall, of a person having to move on the retaining part29, in particular when the acoustic attenuation assembly27is intended to be incorporate into the ceiling of a building.

According to the embodiment represented inFIGS.8and9, the acoustic attenuation assembly27includes a support piece33which is fastened to the retaining element28, and more particularly to the retaining part29, and which extends in a middle part of the retaining part29. The support piece33includes two lateral branches which respectively form the adjacent support elements7of the two acoustic attenuation devices2. The support piece33further includes a central chute34which connects the two lateral branches of the support piece33to each other. The central chute34and the retaining part29delimit a central cavity35.

According to the embodiment represented inFIGS.8and9, the support elements7, which are configured to be located close to the pre-slabs19, each have an angle iron shape and are fastened to the retaining element28, and for example to the lateral bearing parts31.

According to one embodiment of the present disclosure, two adjacent acoustic attenuation assemblies27may be assembled to one another through two assembly pieces36introduced into receiving housings37delimited for example by the lateral bearing parts31.

Advantageously, a concrete layer may be poured over the concrete pre-slabs19and the acoustic attenuation assembly27so as to secure the concrete pre-slabs19and the acoustic attenuation assembly27, and to form a construction element for a building, such as a slab. Fluid flow tubes, such as PEX tubes, may advantageously be positioned on the pre-slabs19and be embedded in the concrete layer, so as to form an active slab.

FIG.10represents an acoustic attenuation assembly27which differs from that represented inFIGS.8and9essentially in that it further includes perforated cover elements38, such as perforated cover plates or perforated cover grids, which partially cover the passage slots12delimited by the support elements7. Advantageously, each perforated cover element38is metallic, and has a perforation rate greater than 70%.

According to the embodiment represented inFIG.10, each perforated cover element38is fastened, preferably in a removable manner, to the cover parts9of the support elements7of a same acoustic attenuation device2.

The acoustic attenuation assembly27represented onFIG.10also includes a closure plate39which is removable and which delimits, with the support piece33, an internal chamber41in which longitudinal elements, such as fluid pipes and/or electric cables, may be disposed. The closure plate39advantageously extends substantially in the plane of extension of the cover parts9of the two adjacent acoustic attenuation devices2.

According to the embodiment represented inFIG.10, the closure plate39rests on internal lateral edges of the perforated cover elements38. According to one variant of the present disclosure, the closure plate39could be removably fastened to the support piece33, and for example to the support elements7adjacent to the two acoustic attenuation devices2.

Such an arrangement of the closure plate39gives a more aesthetic appearance to the acoustic attenuation assembly27. In addition, the presence of the central chute34makes it possible to avoid, for example when fastening longitudinal elements in the internal chamber41, to pierce the concrete layer covering the acoustic attenuation assembly27, and therefore to pierce any fluid flow tubes embedded in the concrete layer.

It goes without saying that the present disclosure is not limited to the embodiments of this acoustic attenuation device, described above by way of examples, on the contrary it embraces all variants. It is thus in particular that each support element could be made of cement concrete, and for example of Ultra High Performance Fiber Concrete (UHPFRC), and that the acoustic attenuation device could include a plurality of passage openings, for example of circular, rectangular or any other shape section, instead of the passage slot.