Step sound damping in building component
Patent Information
- Application Number
- PCT/EP2026/057591
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-21
- Filing Date
- 2026-03-18
- Publication Date
- 2026-09-24
Smart Images
Figure EP2026057591_24092026_PF_FP_ABST
Abstract
Description
[0001] TITLE
[0002] Step Sound Damping in Building Component
[0003] DESCRIPTION
[0004] Field of the Invention
[0005] The invention relates to a connection for concrete elements. More specifically, the invention relates to an embedding box preferably made of plastic that can handle a sound-damping element.
[0006] Background
[0007] It is common today to use prefabricated building elements when constructing both large and small buildings. Different types of building elements such as wall elements, floor elements, stair elements, etc. are then produced at factories that are adapted for production of different building elements, and the finished building elements are transported to the construction site where they are assembled as respective parts of a building being constructed there.
[0008] The prefabricated building elements are usually made of concrete. Concrete is known to transmit sound well, and it is therefore desirable to reduce sound that arises at one location in a building from propagating through the concrete structure of the building and creating disturbances, irritation, and problems for people who live, work, or visit the building.
[0009] A sound-damping connection is described in patent NO345917. The patent concerns a building connection where the damping takes place in the so-called support box or receiver box, which is typically located in the wall where a staircase or a landing is to be attached. Later, it has become desirable to place the damping in the part of the connection element that is cast into the landing because this simplifies the construction process. The damping element itself will typically be a rubber sleeve that lies between a load transfer element and an embedding box that is cast into the landing, both of which are made of metal. More recently, it has become increasingly common to make embedding boxes from recycled plastic. Plastic has a great advantage over metal in that it is cheaper, lighter, and more environmentally friendly.
[0010] A problem with using plastic in an embedding box is that the plastic is not strong enough to be used together with a sound-damping element of, for example, rubber, because the flexibility in the sound-damping element changes the force transfer between the load transfer element and the embedding box and further to the reinforcement steel loops in the building component, and this can lead to crushing of the concrete in the building component.A purpose of the invention is to provide an embedding box of plastic, or another solid material, where the concrete is not crushed when using a sound-damping element.
[0011] A further purpose is to provide a sound-damped building connection that enables reuse of both the building component and the building connection.
[0012] Brief Summary of the Invention
[0013] In a first aspect of the invention, a sound-damping building connection for concrete elements is described. The building connection comprises an embedding box, a load transfer element, and a damping element. The embedding element comprises an inner box end and an open outer box end, where the embedding box is adapted to be cast into a first building component such that the outer box end is flush with a side surface of the first building component. The building connection further comprises a load transfer element for positioning in the embedding box and mounting in a cooperating structure in a second building component. The building connection further comprises a damping element adapted to lie between the embedding box and the load transfer element when the load transfer element is positioned in the embedding box. The embedding box comprises an upper reinforcement element of metal positioned at an upper side of the embedding box closer to the outer box end than the inner box end to receive an upwardly directed force from the load transfer element. In a preferred embodiment, the upper reinforcement element is placed at the outer box end.
[0014] The load transfer element may comprise a hollow tube with a rectangular crosssection with rounded corners, where a load transfer point is a point on a crosssection of the upper side of the load transfer element where the curvature downward toward respective side surfaces of the load transfer element begins, where the upwardly directed force from the load transfer element is mainly transferred at the load transfer points at higher loads, and where the upper reinforcement element at least covers respective load transfer points on each side of the load transfer element. By choosing a width of the reinforcement element that extends beyond the respective force transfer points and up to a point where the reinforcement steel begins to curve downward, the moment arm of forces acting from the load transfer element on the reinforcement steel will be minimized.
[0015] The upper reinforcement element may comprise a steel plate.
[0016] The embedding box may be made of metal and the reinforcement element may be welded to the upper side of the embedding box.
[0017] The embedding box may be made of a plastic product.A lower reinforcement element of metal may be positioned in an underside of the embedding box at an inner end of the load transfer element to receive a downwardly directed force from the load transfer element.
[0018] The embedding box has at least one upper groove for reinforcement steel positioned above the upper reinforcement element and at least one lower groove for reinforcement steel positioned below the lower reinforcement element.
[0019] The embedding box may comprise an upper and lower mounting pocket to receive respective upper and lower reinforcement elements.
[0020] The damping element may be made of a rubber material or a plastic material.
[0021] The damping element fills an annular space that arises between the load transfer element and the embedding box when the load transfer element is placed in the embedding box.
[0022] The embedding box and the receiver box are equipped with ribs to improve stiffness and provide better attachment to the concrete.
[0023] The embedding box may have a length that at least corresponds to the length of the load transfer element and the second building element combined, and may comprise a retraction pocket into which the load transfer element can be retracted so that an outer end of the load transfer element does not protrude beyond the side of the first building component in which it is mounted.
[0024] The load transfer element may comprise an inner bolt hole through which a bolt can be inserted via a bolt slot in the embedding box so that the load transfer element is prevented from moving further out from the embedding box than what corresponds to the depth of the cooperating structure, and where the bolt does not have a bolt head to enable free vertical movement in the bolt slot and to prevent transmission of sound, and where a bolt is positioned in an outer hole in the load transfer element to prevent the load transfer element from moving backward into the embedding box.
[0025] The embedding box comprises an access opening that provides access to the retraction pocket and to the bolt, thereby enabling easier disassembly of the building components, where the access opening comprises four side walls that extend from an upper side of the embedding box to an upper side of the first building element into which the embedding box is cast.
[0026] In a second aspect of the invention, a method for mounting a first building component, in which the building connection as described above is cast, to a secondbuilding component with a cooperating structure is described. The method comprises the following steps:
[0027] a. Pushing the respective load transfer elements, which are mounted in the first building component, into the retraction pocket of the respective embedding boxes so that the load transfer elements do not protrude from the first building component.
[0028] b. Supporting the first building component so that each building connection is aligned with the respective cooperating structures in the second building element and any other building components.
[0029] c. Pushing the respective load transfer elements into the respective cooperating structures.
[0030] d. Securing the load transfer element in the cooperating structure.
[0031] Step c of the method may comprise inserting a bolt in the outer bolt hole to thereby prevent the load transfer element from sliding back into the retraction box, especially if the retraction box is not filled with concrete during attachment.
[0032] In an embodiment of the method, step d of securing the load transfer element in the cooperating unit may comprise filling the cooperating unit or receiver box with concrete. Furthermore, the retraction pocket and access opening may also be filled with concrete to achieve better attachment of the building connection.
[0033] Step d of the method may comprise filling the retraction pocket with a removable material and placing a thin lid of concrete over the removable material in the access opening and greasing the outer end of the load transfer element before it is cast in the cooperating structure, so that the first building component can be released from its adjacent building components for reuse.
[0034] Brief Description of the Figures
[0035] To better understand the invention, some figures are attached where the same features have the same reference in the different figures.
[0036] Fig. 1 shows a building connection according to the invention connecting two building components.
[0037] Fig. 2a and b show an embodiment of the building connection seen from below and a section of the building connection along a centerline B-B.
[0038] Fig. 3 shows an embodiment from Fig. 2a and b in perspective.
[0039] Fig. 4 shows an exploded perspective of the embodiment from Fig. 3.Fig. 5 shows a system of reinforcement steel around the building connection.
[0040] Fig. 6 shows how the forces act on the load transfer element and adjacent building components.
[0041] Fig. 7 shows a section of the building connection with force transfer points on the load transfer element.
[0042] Fig. 8 shows an embedding box of metal where the reinforcement element is welded to the top of the embedding box.
[0043] Fig. 9 shows a reinforcement element attached to an upper side of an embedding box of metal.
[0044] Detailed Description
[0045] In the following, a sound-damping building connection 1 for concrete elements is described. The building connection comprises an embedding box 2, a load transfer element 5, a cooperating structure 3, and a damping element 4. The entire building connection, and how it is positioned between a horizontal and vertical building component, is seen in Fig. 1. An exploded figure of the embedding box, damping element, and load transfer element is shown in Fig. 4.
[0046] The main purpose of the embedding box is to form a cavity in the first building component 12 in which the load transfer element 5 can be positioned. In principle, the building connection 1 can also be between two vertical building components, but since step sound usually arises on horizontal surfaces, most often one of the surfaces / building components where sound damping is used will be horizontal. A typical application of the building connection will be in connection with construction of a floor, a staircase, or a landing.
[0047] The embedding box is adapted for casting into a building component, for example a landing or a staircase, and comprises an open outer box end 25 and an inner box end 24 which is preferably closed.
[0048] The building connection 1 further comprises a load transfer element 5 whose main purpose is to transfer loads from the first building component 12 to the wall in which it is mounted. The load transfer element 5 comprises a preferably tubular metal element with a mainly rectangular cross-section (which in this text also includes, for example, a square cross-section).
[0049] Preferably, the embedding box 2 comprises a retraction pocket 17 that can accommodate the load transfer element so that the load transfer element can bepositioned in the embedding box with an outer end 18 of the load transfer element flush with an outer box end 25 of the embedding box 2. In an advantageous embodiment, shown in Fig. 3, the embedding box 2 further comprises an access opening 19 comprising four side walls 20a, b, c, d to provide access to the retraction pocket 17 and the load transfer element 5 during mounting.
[0050] The building connection 1 cooperates with a cooperating structure 3 in the second building component 30. In an embodiment, the cooperating structure 3 comprises a receiver box 3 that is mounted in the second building component 30 and in which the load transfer element 5 is mounted. Preferably, the receiver box 3 is adapted for casting into a vertical building component.
[0051] Advantageously, the load transfer element may be equipped with an inner bolt hole 10a and an outer bolt hole 10b that cooperate with a bolt 11 and a bolt slot 10c in the embedding box, so that the load transfer element 5 is prevented from moving outward from the embedding box when the bolt 11 is inserted in the inner bolt hole 10a. This is best shown in Fig. 2b. When the bolt 11 is placed in the outer bolt hole 10b, movement of the load transfer element 5 inward into the embedding box 2 is prevented when the bolt hits the outer box end 25. A sliding back of the load transfer element 5 is catastrophic and can lead to collapse of the building component. The outer bolt hole is positioned so that the outer end 18 of the load transfer element extends into the cooperating structure in the second building component.
[0052] Furthermore, the building connection 1 comprises a sound-damping unit, here called a damping element 4, which in a mounted state is positioned between the load transfer element 5 and the embedding box 2 and which preferably, but not necessarily, surrounds the entire load transfer element 5 over its four longitudinal sides as shown in Fig. 4 and Fig. 8. In an advantageous embodiment, the thickness of the damping element is greatest at respective upper and lower load areas 33, 34 as shown in Fig. 2b and Fig. 6, so that the load transfer element 5 achieves a relatively horizontal position under load. Furthermore, it is advantageous with air pockets 34 in the damping element, as shown in Fig. 7, so that the damping element has the ability to expand when loaded.
[0053] Fig. 6 shows how the forces between the load transfer element and the embedding box 2 in the horizontal building component usually behave. The top loads from the first building component 12 will cause a large load at the upper load area 33 at the outer box end 25 of the embedding box 2 and also at the lower load area 32 where an inner end 26 of the load transfer element 5 is located in the embedding box 2. The load is greatest at the upper load area 33 at the outer box end 25 precisely because it is at an end or side edge of the first building component 12 and the forcestherefore cannot be distributed past the edge. At the inner end 26 of the load transfer element 5, the forces are distributed in several directions over a larger area and thereby reduce the probability of fracture, in addition to the forces usually being smaller in this area because most of the length of the load transfer element 5 is inside the embedding box 2. This uneven distribution of the load is amplified when mounting a sound-damping unit because any sound-damping unit has greater flexibility than the load transfer element and embedding box and thus provides greater room for an angle between the load transfer element and the embedding box as shown in Fig. 6.
[0054] Fig. 5 shows a system of reinforcement steel that handles the forces discussed in the previous paragraph. A first and second upper loop 27a, b of reinforcement steel is bent over the outer box end 25 of the embedding box and attached in respective upper grooves 15a in the embedding box for correct positioning of the reinforcement steel; each of the first and second upper loops 27a, b is bent under respective first and second horizontal reinforcement steels 28a, b on the underside of the embedding box 2. Preferably, there is as much direct contact as possible between the metal in the upper reinforcement element 6 and the reinforcement steel.
[0055] The embedding box comprises an upper reinforcement element 6 at the upper load area 33 and preferably a lower reinforcement element 7 at the lower load area 32. In an embodiment, the reinforcement elements 6, 7 comprise a steel plate with an extent in the width direction between two outer side surfaces of the load transfer element as indicated in Fig. 7. Preferably, the extent in the length direction of the upper reinforcement element 6 of the embedding box is at least equal to the extent in the width direction. The extent in the length direction of the lower reinforcement element 7 may be somewhat smaller. It is also possible to imagine an embedding box 2 without a lower reinforcement element 7. Preferably, the upper and lower reinforcement elements 6, 7 are made of metal. In an advantageous embodiment, the embedding box is provided with an upper and lower mounting pocket 8, 9 for the respective upper and lower reinforcement elements 6, 7.
[0056] Figure 7 shows a damping element 4 with a thicker upper side. This is because the load is greatest on the upper side of the load transfer element 5. Strictly speaking, it is only necessary to cover the areas around the respective upper and lower load areas 33, 32 with a sound-damping material so that the damping element only covers these. However, it may be advantageous to also cover the sides of the load transfer element to avoid lateral displacement.
[0057] Fig. 8 shows an embodiment where the upper reinforcement element 6 comprises a steel plate. Preferably, the upper reinforcement element covers at least two force transfer points 37 on each side of the load transfer element 5. The force transferpoint on the respective sides of the load transfer element is positioned where a top surface of the load transfer element begins to curve downward toward its respective side surfaces of the load transfer element. This follows naturally from the fact that the side surfaces of the load transfer element 5 project their stiffness up into the embedding box, while the top surface will yield to a greater extent when the load becomes large. By letting the reinforcement element / steel plate 6 extend somewhat beyond the force transfer points 37, for example up to the point where the reinforcement steel in the loops 27a, b begins to curve downward along the sides of the embedding box 2, the moment arm of the force coming from the load transfer element 5 and acting on the reinforcement steel in the loops 27a, b will be minimal and thereby prevent deformation of the reinforcement steel to the greatest extent possible.
[0058] To achieve good damping, the material of the sound-damping unit 4 should preferably be molded from a chemically mixed plastic material or rubber and have a horizontal extent, i.e., a damping surface, of 200-250 mm2per kN breaking load (for the building connection) and should have a hardness of approximately 58 Shore. Furthermore, the damping element should be dimensionally stable in the sense that it does not sag under load and returns to its original shape when the load is removed. To achieve the desired relationship between extent and breaking load mentioned above, the load transfer element should have a large damping area on the upper surface corresponding to 200-250 mm2multiplied by breaking load expressed in kN. A damping of over 20 dB can be expected.
[0059] In a preferred embodiment, the embedding box is made of a plastic product with the exception of the upper and lower reinforcement plates 6, 7 which are made of metal, preferably steel. Plastic is cheap, lighter than metal, and can be produced from recycled plastic. Sufficient strength for casting is achieved by positioning ribs on the outer side of the embedding box. When using plastic as a material, however, the embedding box 2 must, as mentioned, be reinforced at the upper and lower load areas 33, 32 with an upper and lower reinforcement element 6, 7 in the form of an upper and lower steel plate 6, 7.
[0060] The load transfer element may comprise a hollow tube with a rectangular crosssection with rounded corners, where a load transfer point 37 is a point on a crosssection of the upper side of the load transfer element where the curvature downward toward respective side surfaces of the load transfer element begins, where the upwardly directed force from the load transfer element is mainly transferred at the load transfer points at higher loads, and where the upper reinforcement element 6 at least covers respective load transfer points 37 on each side of the load transfer element. By choosing a width of the reinforcement element 6 that extends beyond the respective force transfer points 37 and up to a point where the reinforcementsteel begins to curve downward, the moment arm of forces acting from the load transfer element on the reinforcement steel will be minimized.
[0061] In an embodiment where the embedding box 2 is made of sufficiently strong metal, the upper reinforcement element 6 can be welded to the upper side of the load transfer element 5, as shown in Fig. 9. In this embodiment, the lower reinforcement element 7 may be superfluous as sufficient strength is achieved by the embedding box. By using standard available tubular steel tubes for both the embedding box and load transfer element in a building connection with sound damping in the embedding box, it is not possible to arrive at a combination of dimensions that enables a solution without an upper reinforcement element 6 without the dimensions resulting in a very heavy and thick building connection 1 and a thick and thus heavy building component.
[0062] A method for mounting a first building component, in which the embedding box is cast, with a second building component with a cooperating structure 3 is also described. The method comprises the following steps:
[0063] a. Pushing the respective load transfer elements that are positioned in respective embedding boxes that are cast into the first building component, into the retraction pocket 17 of the respective embedding boxes 2 so that the load transfer elements do not protrude from the first building component 12. b. Supporting the first building component 12 so that each building connection is aligned with the respective cooperating structures 3 in the second building element 30 and any other building components.
[0064] c. Pushing the respective load transfer elements 5 into the respective cooperating structures 3.
[0065] d. Securing the respective load transfer elements 5 in the respective cooperating structures 3.
[0066] Step d may further comprise filling the respective cooperating structures 3 with concrete. Furthermore, step d may further comprise filling the respective retraction pockets 17 with concrete in such a way that the concrete does not come into direct contact with the load transfer element 5.
[0067] In an embodiment of the method, step c comprises inserting a bolt 11 in the outer bolt hole 10b to thereby prevent the load transfer element 5 from sliding back into the retraction box 17, especially if the retraction box is not filled with concrete during attachment.
[0068] In an embodiment, step d of the method comprises not filling the retraction pocket 17 with concrete, but with a removable material, and a thin layer of concrete isplaced in the access opening 19 on top of the removable material to thereby be able to pull the load transfer element 5 back into the retraction pocket 17 for disassembly of the building component for reuse of the building component and building connection. Furthermore, the outer end of the load transfer element 5 is greased before it is cast in the cooperating structure 3, so that the first building component 12 can more easily be released from its adjacent building components for reuse.
[0069] References
[0070] 1 Building connection
[0071] 2 Embedding box
[0072] 3 Receiver box / Cooperating structure
[0073] 4 Damping element
[0074] 5 Load transfer element
[0075] 6 Upper reinforcement element / steel plate
[0076] 7 Lower reinforcement element / steel plate
[0077] 8 Upper mounting pocket
[0078] 9 Lower mounting pocket
[0079] 10 a, b Bolt holes in the load transfer element and embedding box
[0080] 11 Bolt
[0081] 12 First building component
[0082] 14 Ribs
[0083] 15a, b Upper and Lower grooves for reinforcement steel
[0084] 16 Annular space between embedding box and load transfer element
[0085] 17 Retraction pocket
[0086] 18 Outer end of load transfer element
[0087] 19 Access opening
[0088] 20a, b, c, d Side walls
[0089] 21 Upper side of the embedding box
[0090] 22 Upper side of the first building component
[0091] 23 Side surface of the first building component
[0092] 24 Inner box end of embedding box
[0093] 25 Outer box end of embedding box
[0094] 26 Inner end of load transfer element
[0095] 27a, b First and second outer loops of reinforcement steel at the outer end 25 of the embedding box
[0096] 28a, b First and second lower reinforcement steels
[0097] 29 Upper reinforcement steel
[0098] 30 Second building component
[0099] 31 Side surface of second building component
[0100] 32 Lower load area
[0101] 33 Upper load area
[0102] 34 Air pockets in damping element37 Load transfer points
Claims
CLAIMS1. A sound-damping building connection (1) for concrete elements comprising:an embedding box (2) comprising an inner box end (24) and an open outer box end (25) where the embedding box (2) is adapted to be cast into a first building component (12),a load transfer element (5) for positioning in the embedding box (2) and mounting in a cooperating structure (3) in a second building component (30),a damping element (4) adapted to lie between the embedding box (2) and the load transfer element (5) when the load transfer element (5) is positioned in the embedding box (2),wherein the embedding box (2) comprises an upper reinforcement element (6) of metal positioned at an upper side of the embedding box (2) closer to the outer box end (25) than the inner box end (24) to receive an upwardly directed force from the load transfer element (5).
2. The building connection according to claim 1, wherein the load transfer element (5) is a hollow tube with a rectangular cross-section with rounded corners, wherein a load transfer point (37) is a point on a cross-section of the upper side of the load transfer element (5) where a curvature downward toward respective side surfaces of the load transfer element (5) begins, and wherein the upper reinforcement element (6) at least covers respective load transfer points (37) on each side of the load transfer element (5), wherein the upwardly directed force from the load transfer element (5) is mainly transferred at the load transfer points (37) at higher loads.
3. The building connection according to claim 1 or 2, wherein the upper reinforcement element (6) is a steel plate (6).
4. The building connection according to any of the preceding claims, wherein the embedding box (2) is made of metal and the upper reinforcement element (6) is welded to the embedding box (2) on the upper side of the embedding box 2.
5. The building connection according to any of the preceding claims 1-3, wherein the embedding box (2) is made of a plastic product.
6. The building connection according to claim 5, wherein a lower reinforcement element (7) of metal is positioned in an underside of the embedding box (2) at an inner end (26) of the load transfer element (5) to receive a downwardly directed force from the load transfer element (5).
7. The building connection (1) according to any of the preceding claims, wherein the embedding box (2) has at least one upper groove (15a) for reinforcement steel positioned above the upper reinforcement element (6) and at least one lower groove (15b) for reinforcement steel positioned below the lower reinforcement element (7).
8. The building connection (1) according to any of the preceding claims 5-7, wherein the embedding box (2) comprises an upper and lower mounting pocket (8, 9) to receive respective upper and lower reinforcement elements (6, 7).
9. The building connection (1) according to any of the preceding claims, wherein the damping element (4) is made of a rubber material.
10. The building connection (1) according to any of the preceding claims, wherein the damping element (4) fills an annular space (16) that arises between the load transfer element (5) and the embedding box (2) when the load transfer element (5) is placed in the embedding box (2).
11. The building connection (1) according to any of the preceding claims, wherein the embedding box (2) has a length that at least corresponds to the length of the load transfer element 5 and the depth of the cooperating structure (3), and comprises a retraction pocket (17) into which the load transfer element (5) can be retracted so that an outer end (18) of the load transfer element does not protrude beyond the side of the first building component (12) in which it is mounted.
12. The building connection (1) according to claim 11, wherein the load transfer element (5) comprises an inner bolt hole (10a) through which a bolt (11) can be inserted via a bolt slot (10c) in the embedding box (2) so that the load transfer element (5) is prevented from moving further out from the embedding box than what corresponds to the depth of the cooperating structure (3), and wherein the bolt (11) does not have a bolt head to enable free vertical movement in the bolt slot (10c) and to prevent transmission of sound, and wherein a bolt (11) is positioned in an outer hole (10b) in the load transfer element to prevent the load transfer element (5) from moving backward into the embedding box (2).
13. The building connection (1) according to claim 12, wherein the embedding box (2) comprises an access opening (19) that provides access to the retraction pocket (17) and to the bolt (11) to thereby enable easier mounting and disassembly of the building components, wherein the access opening (19) comprises four side walls (20a, b, c, d) that extend from an upper side (21) of the embedding box (2) to an upper side of the first building element (12).1414. A method for mounting a first building component (12) in which the building connection (1) according to claims 12-14 is cast, to a second building component (30) with a cooperating structure (3) comprising the steps:a. pushing the respective load transfer elements (5), which are mounted in the first building component, into the retraction pocket (17) of the respective embedding boxes (2) so that the load transfer elements do not protrude from the first building component (12),b. supporting the first building component (12) so that each building connection is aligned with the respective cooperating structures (3) in the second building element (30) and any other building components, c. pushing the respective load transfer elements (5) into the respective cooperating structures (3),d. securing the respective load transfer elements (5) in the respective cooperating structures (3) and in the embedding box.
15. Method according to claim 14, wherein step d further comprises filling the retraction pocket (17) with a removable material and placing a thin lid of concrete over the removable material in the access opening (19) and greasing the outer end of the load transfer element (5) before it is cast in the cooperating structure (3), so that the first building component (12) can be released from its adjacent building components for reuse.