EP3464744A1

EP3464744A1 - Partition wall junction

Info

Publication number: EP3464744A1
Application number: EP17725269.9A
Authority: EP
Inventors: Cyrille Demanet; Julian Tizianel; Emmanuel Vial
Original assignee: Etex Building Performance International SAS
Current assignee: Etex Building Performance International SAS
Priority date: 2016-06-03
Filing date: 2017-05-24
Publication date: 2019-04-10
Anticipated expiration: 2037-05-24
Also published as: ZA201807217B; PE20190060A1; CL2018003296A1; AR108660A1; EP3464744B1; BR112018072533A2; CO2018011449A2; WO2017207389A1

Abstract

Provided herein is a construction comprising a junction between a partition wall and an enclosing structure selected from a wall, a ceiling, and a floor; said enclosing structure containing an outer layer formed of panels; wherein said partition wall is positioned against said outer layer, thereby forming an interface between said partition wall and said outer layer. The one or more second panels span the interface and have a damping loss factor which is higher than the damping loss factor of said first panels.

Description

PARTITION WALL JUNCTION

FIELD OF THE INVENTION

Described herein is a construction comprising a junction between a partition wall and an enclosing structure such as a wall, ceiling, or floor.

BACKGROUND OF THE INVENTION

Partition walls are typically non-bearing walls that separate rooms or divide a room. They can be made of various materials, such as bricks, plasterboard, steel panels, concrete, etc. A partition wall typically forms a junction with one or more enclosing structures such as a floor, ceiling, and/or another wall. An important aspect of partition walls is their acoustic performance: a partition wall separating two rooms should prevent as much as possible that noise generated in one room, is being transmitted to the second room. Such transmission of noise may occur via direct sound transmission, or flanking sound transmission. This is illustrated in Fig. 1 , showing a partition wall (1 ) separating rooms A and B, and forming a T-junction with a lateral wall (2). A sound generated in room A may reach room B via direct sound transmission via the partition wall (solid arrow); or flanking sound transmission via the lateral wall (dashed arrow).

Direct sound transmission may be reduced in various ways, e.g. by making the partition wall heavier, and/or by constructing the wall from boards (e.g. plasterboard) separated by a gap filled with acoustic insulation.

Flanking sound transmission, also known as "indirect sound transmission", is particularly relevant when the lateral wall is provided with an outer layer of building boards or panels, e.g. plasterboard or fiber cement panels. Fig. 2 shows a configuration showing a partition wall (1 ) separating rooms A and B, forming a junction with a lateral wall (2), forming an interface (6). The lateral wall (2) is provided with an outer layer (3) formed of building panels or boards (4), which are fixed on studs (7). The configuration of Fig. 2 is not recommended in the art, as there is a considerable degree of flanking sound transmission via the panels (4). Instead, it is recommended to use a design wherein the outer layer (3) of the lateral wall (2) is interrupted. An example of such a junction is shown in Fig. 3. In this configuration, the outer layer (3) is interrupted by the partition wall (1 ), thereby preventing flanking sound transmission via the outer layer (3). Sound transmission via the rest of the wall can be reduced by providing the space between the studs (7) with acoustic insulation material, and/or by using adapted studs. Despite the improved acoustic properties, the configuration of Fig. 3 also has some disadvantages. In particular, the installation of walls in such a configuration is more complex and time consuming compared to the configuration of Fig. 2. For example, the configuration of Fig. 3 typically requires more studs and screws, and more boards to be cut.

Patent NL1006145 describes a sound isolating structure for positioning between a ceiling and a corresponding suspended ceiling. The structure comprises an insulation material which forms an extension of a partition wall. Therefore the suspended ceiling is interrupted by the insulation material, such that the structure does not leave a smooth surface when the partition wall is later removed.

Patent application EP2228500 describes a sound reducing structure comprising a partition wall forming a T-junction with a suspended ceiling, provided underneath a basic ceiling provided with a suspended ceiling, said structure being provided with a silencer element having sound reducing or absorbing properties. The structure requires a space between the suspended ceiling and the basic ceiling for accommodating the silencer. There remains a need for solutions which are simple to install, but are still able to significantly reduce flanking sound transmission via the outer layer of panels.

SUMMARY OF THE INVENTION

The present inventors surprisingly found that in a configuration as shown in Fig. 2, flanking sound transmission can be reduced dramatically by simply replacing the panels along the junction (6) by panels having a higher damping loss factor than the other panels of the outer layer (3). This is surprising, as it is generally accepted that a configuration as shown in Fig. 2 is a bad design. Therefore, provided herein are the following aspects:

Aspect 1 . A construction comprising a junction between a partition wall and an enclosing structure selected from a wall, a ceiling, and a floor; said enclosing structure containing an outer layer formed of panels; wherein said partition wall is positioned against said outer layer, thereby forming an interface between said partition wall and said outer layer; characterized in that said outer layer comprises a single layer of panels comprising first panels and one or more second panels , said first panels and one or more second panels being arranged parallel to said enclosing structure, wherein:

- said one or more second panels are positioned between said first panels;

- said one or more second panels have a damping loss factor which is higher than the damping loss factor of said first panels; and - said one or more second panels span said interface. Aspect 2. The construction according to aspect 1 , wherein the damping loss factor of one or more of said second panels is at least two times higher than the damping loss factor of said first panels.

Aspect 3. The construction according to aspect 1 or 2, wherein said one or more second panels extend from 10 cm up to 120 cm from said interface. Aspect 4. The construction according to any one of aspects 1 to 3, wherein said one or more second panels are laminated panels comprising two or more substrate layers bonded to each other.

Aspect 5. The construction according to any one of aspects 1 to 4, wherein the colour of said first panels is different from the colour of said one or more second panels.

Aspect 6. The construction according to any one of aspects 1 to 5, wherein said first panels and said second panels are based on a hydraulic binder. Aspect 7. The construction according to aspect 6, wherein said first panels and said second panels are plasterboard panels.

Aspect 8. The construction according to any one of aspects 1 to 7, wherein said enclosing structure is a wall.

Aspect 9. The construction according to any one of aspects 1 to 8, wherein at least one of said one or more second panels has a length of at least 100 cm. Aspect 10 The construction according to any one of aspects 1 to 9, wherein the damping loss factor of said second panels is at least 0.05.

Aspect 1 1 The construction according to any one of aspects 1 to 10, wherein said outer layer of panels forming the interface is formed of the second panels, and wherein the first panels do not form part of the interface.

Aspect 12. Use of a construction according to any one of aspects 1 to 1 1 , for the reduction of flanking sound transmission.

The independent and dependent claims set out particular and preferred features of the invention. Features from the dependent claims may be combined with features of the independent or other dependent claims, and/or with features set out in the description above and/or hereinafter as appropriate.

The construction provided herein can provide excellent acoustic properties, and allows for maintaining a continuous outer layer (3) of panels on the enclosing structure with which the partition wall is joined. This not only makes it less complex to install the install the junction between the partition wall and enclosing structure, but it also allows for subsequent removal of the partition wall with minimal effect on the integrity of the enclosing structure.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description which illustrates, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying Figures are provided by way of example only and should not be considered to limit the scope of the present invention.

Fig. 1 Schematic illustration of direct sound transmission (solid arrow) and flanking sound transmission (2) between two rooms (A and B) separated by a partition wall (1 ) forming a T-junction with a lateral wall (2).

Fig. 2 T-junction formed by a partition wall (1 ) separating two rooms (A and B) and a lateral wall (2) having an outer layer (3) of panels (4). This configuration is known in the art but not recommended.

Fig. 3 T-junction formed by a partition wall (1 ) separating two rooms (A and B) and a lateral wall (2) having an outer layer (3) of panels (4). This configuration is known in the art and recommended.

Fig. 4 T-junction according to a particular embodiment of the construction described herein, formed by a partition wall (1 ) separating two rooms (A and B) and a lateral wall (2) having an outer layer (3) of panels (4, 5).

Fig. 5 T-junction according to a particular embodiment of the construction described herein, formed by a partition wall (1 ) separating two rooms (A and B) and a lateral wall (2) having an outer layer (3) of panels (4, 5). The partition wall (1 ) is made using panels (4) separated by studs (7). The partition wall (1 ) and the lateral wall (2) are provided with acoustic isolation material (8) for further reducing sound transmission.

In the Figures, the following numbering is used:

1 - partition wall; 2 - lateral wall; 3 - outer layer; 4, 5 - panel; 6 - interface; 7 - stud; 8 - acoustic isolation material. DETAILED DESCRIPTION OF THE INVENTION The present invention will be described with respect to particular embodiments.

It is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, steps or components as referred to, but does not preclude the presence or addition of one or more other features, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Throughout this specification, reference to "one embodiment" or "an embodiment" are made. Such references indicate that a particular feature, described in relation to the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, though they could. Furthermore, the particular features or characteristics may be combined in any suitable manner in one or more embodiments, as would be apparent to one of ordinary skill in the art.

The following terms are provided solely to aid in the understanding of the invention. When reference is made to weight percentage (wt%), this is to be understood, unless differently specified, as the weight of the component expressed as percentage over the total weight of the composition in which the component is present.

The term "gypsum" as used herein refers to calcium sulfate dihydrate (DH), i.e. CaS0₄-2H₂0. Gypsum which is present in plasterboards typically is obtained via the hydration of plaster.

The term "plaster" or "stucco" as used herein and in the generally accepted terminology of the art, refers to a partially dehydrated gypsum of the formula CaS0₄-xH₂0, where x can range from 0 to 0.6. The term "plaster" is also referred to herein as "hydratable calcium sulfate". The term "dry weight" when referred to plaster in a plaster composition, refers to the weight of the calcium sulfate including hydration water (i.e. the xH₂0 of the above formula), but excluding any gauging water in the composition. Plaster can be obtained via the calcination of gypsum, i.e. the thermal treatment of gypsum in order to remove (a part of) the combined water. For the preparation of plaster, natural or synthetic gypsum may be used. Natural gypsum may be obtained from gypsum rock or gypsum sand. Synthetic gypsum typically originates from flue gas desulfurization (FGD) or phosphoric acid production. Plaster wherein x is 0.5 is known as "calcium sulfate hemihydrate" (HH) or "calcium sulfate semihydrate" (SH), i.e. CaSCy0.5H₂O. Calcium sulfate HH can occur in different crystalline forms; known as a and β. Calcium sulfate HH is also known as "gypsum plaster" or "plaster of Paris".

Plaster wherein x is 0 is known as "calcium sulfate anhydrite" or "anhydrous calcium sulfate". "Calcium sulfate anhydrite I I I" (AI M) refers to a dehydrated H H with the potential of reversibly absorbing water or vapor. "Calcium sulfate anhydrite II" (All) refers to the completely dehydrated calcium sulfate (CaS0₄). Al l is formed at higher temperatures and is preferably not used for the preparation of plasterboard.

The terms "plasterboard", "gypsum board", and "drywall" are used herein interchangeably and refer to a panel or board comprising a gypsum core, obtainable from a plaster slurry as described herein. Accordingly, the term "plasterboard" refers to a board or panel which is obtainable via the setting (hydration) of plaster. The term "board" or "panel" as used herein refers to any type of wall, ceiling or floor component of any required size.

The term "about" as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/-10% or less, preferably +1-5% or less, more preferably or less, and still more preferably +/-0.1 % or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier "about" refers is itself also specifically, and preferably, disclosed.

Provided herein is a construction comprising a junction between a partition wall and an enclosing structure comprising an outer layer formed of building panels or building boards. The construction described herein is based on the finding of the present inventors that even when the outer layer is not interrupted by the partition wall, flanking sound transmission can be reduced dramatically by replacing the panels along the junction between the partition wall and the enclosing structure by panels having a higher damping loss factor compared to the other boards of the outer layer. In this way, improved acoustic properties can be obtained, while maintaining a continuous outer layer (3) of panels on the enclosing structure with which the partition wall is joined. This facilitates the installation and subsequent removal of the partition wall. Moreover, the construction described herein only requires a minimal amount of expensive panels with high damping loss factor, thus keeping the panel cost low. More particularly, provided herein is a construction comprising a junction between a partition wall and an enclosing structure which contains an outer layer comprising a single layer of panels or boards, which are arranged parallel to the enclosing structure. Accordingly, the outer layer is positioned parallel with the enclosing structure. The term "parallel" as used herein is not limited to perfectly parallel orientations and include substantially parallel and approximately parallel configurations. In particular, deviations less than 5°, preferably less than 3°, and more preferably less than 1 ° from a parallel orientation are included.

The partition wall is positioned against the outer layer, thereby forming an interface between said partition wall and said outer layer.

The outer layer comprises first panels and one or more second panels; each of said first and second panels having a damping loss factor, wherein the second panels are flanked by (i.e. positioned between) the first panels, and wherein the damping loss factor of the one or more second panels is higher than the damping loss factor of the first panels. Moreover, the one or more second panels are present on at least a part of said interface along the entire thickness of said partition wall. Since the partition wall is positioned against the outer layer and the second panels are present on the interface between the outer layer and the partition wall, the second panels are contacting the partition wall. This will be explained further herein below.

The construction described herein comprises a partition wall; i.e. a wall that separates rooms, or divides a room in parts. The partition wall is typically not load-bearing, but it is not excluded that in certain embodiments, the partition wall may be load-bearing.

The partition wall may be constructed of various materials, including but not limited to plasterboard, (fiber) cement board, steel panels, bricks, clay blocks, terra-cotta blocks, concrete blocks, glass blocks, etc. In a preferred embodiment, the partition wall may be made of plasterboard. Methods and materials for the construction of such walls are well known in the art and will not be discussed further herein.

Although not critical, the partition wall preferably spans the entire distance between the floor and ceiling of the rooms to be separated, or room to be divided. This allows to obtain optimal acoustic properties.

In particular embodiments, the partition wall will have a planar shape and be vertically oriented. However, other shapes and orientations are not excluded. For example, in particular embodiments, the wall may be curved and/or slanted. The construction described herein further comprises an enclosing structure. The term "enclosing structure" as used herein refers to a part of a construction that encloses a room or part thereof. Thus, the enclosing structure provides at least a part of the interior surface of a room. Typically, the enclosing structure will be a wall, ceiling, or floor. These enclosing structures may be made of many materials, as is known in the art.

In preferred embodiments, the enclosing structure may be a wall, which can be load- bearing or not load-bearing. This wall may be an exterior wall of a building, or an interior wall.

Similar to the partition wall, the wall forming the enclosing structure will typically have a planar shape and be vertically oriented, although other shapes and orientations are not excluded. If the enclosing structure is a floor or ceiling, the enclosing structure will typically have a planar shape and be horizontally oriented, although other shapes and orientations are not excluded. The enclosing structure of the construction described herein comprises an outer layer formed of panels or boards, hereinafter referred to as "outer layer". When referring to the enclosing structure or parts thereof, the terms "external" and "outer" as used herein, refer to the side of the enclosing structure facing the partition wall.

The panels may be used to conceal elements of the enclosing structure such as insulating materials, cables, bricks, etc. Additionally or alternatively, the panels may serve a variety of other purposes. For example, the panels may provide fire protection, reduce direct sound transmission through the enclosing structure, etc.

Typically, the panels are mounted on a structure made of studs or laths, which are often made of metal and/or wood. Methods and materials for installing panels are well known and will not be discussed further herein.

The outer layer is made of a single layer of panels comprising the first panels and the second panel(s). Accordingly, the installation of the outer layer is largely similar as the installation of a conventional wall lining, which is well known to installers.

Although the outer layer is made of a single layer of panels, it is not excluded that in certain embodiments, one or more additional layers of panels may be provided between the outer layer and the enclosing structure. Such additional layers may comprise a combination of first and second panels, similar to the outer layer.

The panels or boards may be made of many materials. In preferred embodiments, the panels or boards of the outer layer are based on a hydraulic binder, for example plaster or cement. In particular embodiments, the panels are gypsum boards or fiber cement panels.

In preferred embodiments, the panels of the outer layer comprise or are gypsum boards. Gypsum boards are well known in the art and typically comprise a core comprising gypsum, wherein the core typically is pressed between a pair of facers or liners. The core may comprise other components than gypsum, but typically contains at least 85 wt% gypsum. The dimensions and shape of the gypsum board described herein are not critical. Typically, the gypsum board will have a standard thickness ranging from 5 to 100 mm. In preferred embodiments, the gypsum board has a thickness of about 12.5 mm. The gypsum board typically has a rectangular shape, although other shapes may also be envisaged.

In the construction described herein, the partition wall and the enclosing structure form a junction. More particularly, the partition wall contacts the outer layer of the enclosing structure, wherein the outer layer is not interrupted by the partition wall. In other words, the partition wall is positioned against the outer layer, thereby forming an interface between the partition wall and the outer layer, hereinafter referred to as "interface". The skilled person will understand that if the partition wall is (partially) hollow, the interface can include parts of the outer layer which are concealed by the partition wall, but are not in direct contact with the partition wall.

Typically, the junction will be a T-junction, i.e. a junction in the shape of the letter "T". More particular, the transverse cross-section of the partition wall and the enclosing structure may be T-shaped. In preferred embodiments, the partition wall and the enclosing structure join one another at an angle between 80° and 100°, more preferably about 90°. However, in certain embodiments, other angles may be used.

In a typical construction, the partition wall will form a junction with more than one enclosing structure. For example, the partition wall may form a junction with a wall, a ceiling, and a floor. In the construction described herein, it is sufficient that only one of these enclosing structures is provided with an outer layer of panels as described above. Nevertheless, in certain embodiments, two or more of the enclosing structures contacting the partition wall may be provided with such outer layer.

In the construction described herein, the outer layer of panels of the enclosing structure comprises first panels and one or more second panels, each having a damping loss factor. The damping loss factor η (eta), also known as "modal damping loss factor" or "damping ratio", is a dimensionless measure describing how oscillations in a system decay after a disturbance. The damping loss factor can be determined by means of a Mechanical Impedance Measurement (MIM), using the method developed for laminated glass and standardized in ISO 16940:2008; with the adaptations for plasterboard (sampling and measurement conditions) as described in Annex F of European standard EN 16703:2014. In short, beam samples having dimensions of 600 mm x 60 mm are cut out of the specimen to be tested and glued (with a cyanoacrylic glue) to a shaker (15 mm diameter) at its center point. The FRF (frequency response function) of this free-free beam system is analyzed by measuring the punctual velocity and the input force. The application of the 3 dB rule to the anti-resonances of the mechanical impedance enables to the modal damping loss factor of the specimen at different frequencies. The damping loss factor is typically measured at a temperature of 20°C ± 3°C, more preferably at 20°C. As used herein, the term "damping loss factor" refers to the average damping loss factor (measured as described above) over all modes (resonance frequencies) ranging from 100 Hz and 2000 Hz. Accordingly, for each sample, the resonance frequencies from 100 Hz and 2000 Hz are determined, and the corresponding damping loss factor determined. Then, the average over all damping loss factors is determined.

In what follows, the damping loss factor of the first panels will be referred to as "first damping loss factor", and the damping loss factor of the one or more second panels will be referred to as "second damping loss factor". However, this does not mean that the first panels all have an identical damping loss factor. Indeed, although the first panels may all have the same damping loss factor, this is not critical. Hence, it is not excluded that in certain embodiments, the first panels may comprise panels having a different damping loss factor. In such embodiments, the damping loss factor of each second panel will be higher than the damping loss factor of each of the first panels flanking said second panel.

The first and second panels are selected such that the second damping loss factor is higher than the first damping loss factor. Standard plasterboard typically has a damping loss factor below 0.02. Acoustic plasterboard typically has a damping loss factor above 0.05. In particular embodiments of the construction described herein, the second damping loss factor is at least two times higher than said first damping loss factor. In further embodiments, the second damping loss factor is at least three times higher than the first damping loss factor. In yet further embodiments, the second damping loss factor is at least four, five, six, seven, eight, nine, or ten times higher than the first damping loss factor.

Methods for the manufacture of panels having a high damping loss factor are known in the art. Common acoustic panels include laminated panels, comprising two or more panels which are bonded with an adhesive material, preferably a viscoelastic glue. Examples of such panels are described in EP2406437, which is hereby incorporated by reference. Thus, in particular embodiments, one or more of the second panels may be laminated panels comprising two or more substrate layers bonded to each other by an adhesive material. Panels having an increased damping loss factor may also be obtained with adhesive polymers with shear modulus below 10 MPa.

The first panels may be made of similar materials as the second panels, or from different materials. For example, the first panels may be fiber cement panels whereas the second panels are (laminated) plasterboard panels. In preferred embodiments, the first panels and the second panels are both plasterboard panels; wherein the second panels are preferably laminated plasterboard panels.

In the construction described herein, the second panels are flanked by (i.e. positioned between) the first panels. In other words, within the outer layer of panels, the first panels are positioned laterally to the second panels, at two opposing edges. More particularly, when a partition wall separating a first and a second room is positioned against the second panel, at least one first panel neighbouring the second panel will be present in the first room, and at least one first panel neighbouring the second panel will be present in the second room.

The one or more second panels at least partially span the interface between the partition wall and the outer layer of the enclosing structure. Accordingly, the interface is at least partially formed by the second panel(s). Preferably, the one or more second panels span at least 75% of the interface surface. More preferably, the one or more second panels span at least 90% of the interface surface, at least 95% of the interface surface, or even at least 99% of the interface surface.

In preferred embodiments, the one or more second panels essentially span the entire interface. Thus, the one or more second panels may be provided essentially along the entire interface; i.e. essentially provided along the entire thickness of the partition wall; and along the entire height of the partition wall (in case the enclosing structure is a wall) or the entire length of the partition wall (in case the enclosing structure is a floor or ceiling). In preferred embodiments, at least a part of the outer layer of panels forming the interface is formed of the second panels, whereas the first panels do not form part of the interface. Preferably, the second panels contact the partition wall (at the interface), whereas the first panels do not contact the partition wall.

In cases wherein the partition wall has a variable thickness along its length and/or height, the relevant thickness is the thickness measured along the interface, and at the same height of the part of the second panel in question. The skilled person will understand that this does not exclude that, in case the interface is made of two or more adjacent second panels (within the same layer), there may be joints between the panels which may be filled with a jointing compound. Thus, the interface may comprise joints between panels, but is generally free from gaps along the interface. An advantage of the construction described herein is that there are no specific requirements for the jointing compound in order to obtain good acoustic properties. Preferably, the joints have a width below 10 mm.

In case the interface comprises two or more second panels, each panel preferably spans the entire thickness of the partition wall. Any joints between the second panels are typically oriented perpendicular to the partition wall.

Typically, the length and/or width of the one or more second panels will exceed the thickness of the partition wall. Thus, the one or more second panels will typically form a part of the outer layer outside the interface. In particular embodiments, the one or more second panels extend at least 10 cm from said interface, at each side of the partition wall. Preferably, the one or more second panels do not exceed more than 120 cm from the interface.

The dimensions of the panels are not critical. Nevertheless, the second panels preferably have a width ranging from 600 mm to 1200 mm. The second panels preferably have a length ranging from 450 mm to 3600 mm. The long side of the second panels may be oriented parallel with or perpendicular to the interface, or at any angle in between.

In particular embodiments, the first panels have an external colour which is different from the colour of the second panels. This can facilitate the correct installation of the construction described herein, as it allows for a visual check of the correct positioning of the first and second panels. Additionally or alternatively, the panels may be provided with certain patterns, drawings, text, etc. which allow for a visual check.

The acoustic properties of the construction described herein may be improved further by providing the construction with a silencer element as described in patent application EP2228500. The silencer element is then provided between the outer layer and the enclosing structure.

Further provided herein is the use of a construction as described hereabove, for the reduction of flanking sound transmission. More particularly, the construction can be used for reducing the transmission of sound between a first and second room separated by a partition wall, via the of the outer layer of the enclosing structure.

EXAMPLES

The following examples are provided for the purpose of illustrating the present invention and by no means are meant and in no way should be interpreted to limit the scope of the present invention.

Fig. 4 schematically shows a detail of a T-junction according to a particular embodiment of the construction described herein, formed by a partition wall (1 ) having a thickness t separating two rooms (A and B) and a lateral wall (2) having an outer layer (3) of panels (4, 5), which are mounted on metal studs (7). The partition wall (1 ) is positioned against the outer layer (3), thereby forming an interface (6). The outer layer is made of first panels (4) having a low damping loss factor, except at the interface (6), where a second panel (5) having a higher damping loss factor is used. It can be seen that the second panel spans the entire thickness (t) of the partition wall (1 ), and even exceeds the interface (6) at both sides of the partition wall (1 ).

Fig. 5 schematically shows a detail of a T-junction according to a particular embodiment of the construction described herein. The junction is similar to the junction of Fig. 4, except in that the partition wall is also made of panels (4) mounted on studs (7). Such types of partition walls are well known in the art. Furthermore, the acoustic performance of the partition wall (1 ) and lateral wall (2) is improved by filling the spaces between the studs (7) with acoustic insulation material (8). The influence of the replacement of the panels (4) at the interface (6) by panels (5) having a higher damping loss factor was assessed according to NF EN ISO 10848-2. This test is to measure the standardized lateral acoustic airborne sound insulation (D_nf) of building components such as facades or between to adjacent rooms. This isolation is obtained by the difference between the levels of the sound pressure averaged in space and in time, produced in two rooms by a sound source located in one of the two rooms. The transmission is supposed to occur by a specified side path between the two premises (e.g. a fagade). D_nf is normalized with respect to the reference equivalent absorption area (AO = 10 m²) .

In a first configuration, only Pregyplac BA18 plasterboard panels (available from Siniat, France) were used (average damping loss factor of 0.01 1 between 100-2000 Hz). In a second configuration, the same panels were used, except at the interface with the partition wall, where Pregytwin BA18 plasterboard panels were used (average damping loss factor of 0.103 between 100-2000 Hz). Both panels are available from Siniat, France.

In both configurations, the flanking normalized level difference(D_nf,w) was measured. In the first configuration, a value of 42 dB was measured, whereas a value of 64 dB was measured in the second configuration. This huge difference shows that the construction described herein indeed can provide a much better acoustic performance.

Claims

A construction comprising a junction between a partition wall and an enclosing structure selected from a wall, a ceiling, and a floor; said enclosing structure containing an outer layer formed of panels; wherein said partition wall is positioned against said outer layer, thereby forming an interface between said partition wall and said outer layer; characterized in that said outer layer comprises a single layer of panels comprising first panels and one or more second panels, said first panels and one or more second panels being arranged parallel to said enclosing structure, wherein:

- said one or more second panels are positioned between said first panels;

- said one or more second panels have a damping loss factor which is higher than the damping loss factor of said first panels; and

- said one or more second panels span said interface.

The construction according to claim 1 , wherein the damping loss factor of one or more of said second panels is at least two times higher than the damping loss factor of said first panels.

The construction according to claim 1 or 2, wherein said one or more second panels extend from 10 cm up to 120 cm from said interface.

The construction according to any one of claims 1 to 3, wherein said one or more second panels are laminated panels comprising two or more substrate layers bonded to each other.

The construction according to any one of claims 1 to 4, wherein the colour of said first panels is different from the colour of said one or more second panels.

The construction according to any one of claims 1 to 5, wherein said first panels and said second panels are based on a hydraulic binder.

The construction according to claim 6, wherein said first panels and said second panels are plasterboard panels.

8. The construction according to any one of claims 1 to 7, wherein said enclosing structure is a wall.

9. The construction according to any one of claims 1 to 8, wherein at least one of said one or more second panels has a length of at least 100 cm.

10. The construction according to any one of claims 1 to 9, wherein the damping loss factor of said second panels is at least 0.05.

1 1 . The construction according to any one of claims 1 to 10, wherein said outer layer of panels forming the interface is formed of the second panels, and wherein the first panels do not form part of the interface.

12. Use of a construction according to any one of claims 1 to 1 1 , for the reduction of flanking sound transmission.