FI89398C - Procedure for improving the sound insulation ability of a cavity-seen building plate and building plate combination with good sound insulation ability - Google Patents

Description

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The present invention relates to the construction of precast concrete elements and to concrete subfloors and walls used therein. In particular, the invention relates to a method according to the preamble of claim 1 for improving the sound insulation capacity of slab-like building elements.

According to such a method, a planar material layer is arranged from a spaced-apart hollow slab-like building element, and spacers of substantially flexible material separating the material layer and the building element are provided in the space between said material layer and the slab-like building element.

The invention also relates to a slab-like building element combination according to the preamble of claim 5, which has a good sound insulation capacity. Such a combination comprises a first hollow building slab, at least one second building slab spaced apart from the first building slab, and spacers arranged between the first and second slabs made of a resilient material.

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Precast concrete construction has brought the possibility of industrial manufacturing to the manufacture of building components. However, there are certain sound insulation problems associated with prefabricated construction - as well as on-site construction. Thus, when the house: 30 is assembled from parts, a lot of joints are formed in the structures and sound leaks are corresponding to them. Likewise, the quest for lightweight structures puts sound attenuation in front of many demands. Although prefabricated building tiles are used, some construction steps can only be carried out at 35 construction sites, in which case the work accuracy varies according to the natural conditions. Similarly, deformations in concrete over time must be taken into account in the structure.

The sound insulation of buildings can be largely determined by theoretical -... 40 tis calculation models. Based on the experimental research results, they can be validated in the case of new solutions.

Factors affecting the damping of mechanical vibration 5 in the subfloor are 1. mass of the structure 2. resonances 3. coincidence phenomenon 10 4. floor covering 5. lateral displacement

Solutions are known from the patent literature in which an attempt has been made to take into account some of these 15 factors in order to improve sound attenuation.

DE patent publication 714339 from 1941 discloses a solution in which flexible, rubber elements are used between two plates or plates to keep the plates apart and to make air space between the plates.

A similar solution is disclosed in FI patent publication 48115, in which case the elements holding the plates loose are a string impregnated with hart-25.

The method of isolating the impact sound of the midsole is disclosed in FI patent publication 29753, in which the hard fiber boards are separated from each other by resilient pieces which are point-like and keep the boards apart from each other and at the same time together.

FI patent 29859 continues the invention of the previous patent in that the resilient material is introduced between the concrete slabs by means of paper or a similar layer to which the resilient material is applied 35 points or lines at regular intervals. According to the patent, the distance between the resilient points depends on the frequency of the sound to be isolated according to a certain formula.

FT patent application 9167/73 discloses a solution according to the previous 3 39353, in which the elements keeping the insulating layers apart are mineral wool.

In the prefabricated midsole tiles, the solution model for the sound insulation problems 5 has become the so-called so-called floating tile to improve sound insulation satisfactorily. According to the state of the art, a floating floor is formed by a flexible layer of medium placed on a load-bearing structure and a cast concrete slab or the like on top of it.

The space between the floating structure, the surface plate, and the load-bearing part is essential for sound insulation. The air in this state forms a pneumatic spring which dampens the movements of the surface plate - and at the same time the propagation of the sound - which cooperates with the flexible medium or springs as a spring combination. As the thickness of said space increases, the sound attenuation of the structure improves.

20 However, the technology described above has significant drawbacks and shortcomings.

The goal of industrial construction is to transfer as many work steps as possible to the factory. Instead, the casting of the floating surface tile 25 is currently done on site, so it does not meet this goal.

Floating floors are large. Assuming that the surface tile would be made of a 4 cm thick layer of concrete and that the required specific frequency is 10 Hz, it should be: f = 60 / V (md) m = mass d = 4 cm f = 10 Hz - 35 air gap thickness approx. 38 cm.

Considering that, in practice, the spring effects of the flexible material and the air operate simultaneously, the gap or concrete slab becomes even thicker.

In order to maintain a 30 cm smaller size in the substructure and the optional floor coverings, a compromise must be made between the mass of the structure, the strength of the airspace and the approved characteristic frequency. Usually, for several reasons, hollow core slabs are still sought, in which case the mass of the structure is further reduced.

10 The problems with the prior art in isolating impact sound in midsoles have been described above. In wall structures, shock absorption is not as big a problem as in midsoles. However, current audio devices are capable of reproducing quite loud sounds that are poorly attenuated by simple structures. This so-called airborne problem could be solved by completely separate two-part walls, but they are too expensive in most practical applications.

The object of the present invention is to eliminate the drawbacks associated with the prior art and to provide a new solution, in particular for improving the sound insulation of hollow concrete slab structures.

25 The aim is to adequately attenuate noise, especially when aiming at lightweight building components. In particular, it is desired to provide a solution which can combine the attenuation of footsteps with the free choice of the surface material of the midsole. It is also desired to increase the airborne sound insulation of midsoles and walls.

The invention is based on the idea that in the known floating plate combination the space between the surface plate and the body part is increased by connecting it with the cavities of the run-35 part by means of openings. This solution reduces the stiffness of the above-mentioned spring combination, whereby the sound attenuation is enhanced. According to the invention, the surface area of the openings to be formed is chosen so that the hole-free portion of the body part still functions as a structural part.

More specifically, the method according to the invention is mainly characterized by what is set forth in the characterizing part of claim 1.

The building element combination according to the invention is in turn characterized by what is set forth in the characterizing part of claim 5.

For the purposes of this application, a "hollow slab-10a" is a building element having at least one cavity extending in the longitudinal or width direction of the building element. The cavity is preferably empty (air-filled) or may contain some e.g. porous material. It is essential, however, that the material in the cavity does not substantially impede compression and expansion.

A planar "layer of material" to be mounted adjacent to or on top of a hollow slab may consist of any material capable of distributing weight over a wide area. Thus, various concrete slabs and slabs, gypsum slabs and slabs, chipboard, fiberboard, and the like can be incorporated into the ky-20. The layer thickness to be selected varies depending on the strength properties required in the application.

The invention provides considerable advantages. Thus, increasing the air volume and at the same time the height of the air column between the surface plate and the body part makes it possible to reduce the height required by the flexible layer. At the same time, partial coverage will be achieved with the flexible layer, which provides • additional 30 options for selecting the spring properties of the flexible layer.

The sound insulation achieved with the solution is good. Where the structure known as the Nilcon slab maximizes the mass of the load-bearing portion and the solid slab maximizes the mass of the load-bearing portion, the structure according to the invention achieves sound attenuation corresponding to the maximum air space and at the same time a higher frame height than the solid slab.

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In wall structures, a load-bearing wall or partitioning wall constructed in accordance with our invention provides opportunities for good airborne sound insulation. In this case, we get a lighter wall than the current wall structures and better airborne sound attenuation.

5

According to the invention, openings extending up to the cavity of the slab are formed in the upper surface of the midsole, i.e. in its pressing surface. These preferably have a surface area of 10 to 50% of the total surface area. The ratio of the compression part of the structural part to the area of said sound openings is determined by the structural factors and the strength of the concrete used. Typically, the openings make up about 15 to 35% of the pressing surface, in which case the gap-free portion of the structure still functions well as a pressing surface in accordance with building standards.

15 High-strength new concrete-type materials have opened up new possibilities for manufacturing building components in industrially highly automated plants. In this case, even economically difficult structures can be implemented, such as, for example, intermediate bases built of several parts and partition walls. 20 High strength can be utilized using a cellular structure so that the structures can be made substantially lighter than normal concrete. However, lighter parts do not work as well with heavier sections under sound attenuation mass law as heavier ones; therefore, the efficient use of the spring effect of airspace is important, especially in the context of these components.

According to the present invention, it is preferred, but not necessary, to cast at least a floating surface or cover slab of concrete in which the larger aggregate has been replaced by polystyrene beads or similar soft particles. This results in light and strong, but above all workable concrete, which is referred to here as aerated concrete.

As a side effect of high strength, deformations of structures decrease. Reduced deformations and cellular structure provide the basis for the manufacture of dimensionally accurate building components, e.g. by machining. If the sound insulation board is made, for example, on top of a typical hollow core slab with prestressed steel reinforcements, machining is particularly important for straightening the slab V 89398 from the typical curvature defects of the hollow core slab. Sound-insulated machined parts reduce seam leaks and also reduce errors on the construction site.

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According to a preferred embodiment of the invention, there is thus provided a prefabricated building tile assembly in which a cover plate made of aerated concrete or the like is supported on the on-rolled intermediate base, supported by flexible spacers. Since both tiles are made to dimensional accuracy, the building tile combinations according to the invention can easily be used to produce uniform intermediate bases, which practically completely lack the clearances between the tiles.

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In connection with the invention, a preferred midsole structure has been developed, which consists in cross-section of two low U-shaped plates, which are placed opposite U-prongs, leaving a central cavity between them. Permeable openings are then formed in the shell of the U-shaped U-shape, either during or after casting, which in the plate combination connects the air space between the cover plate and the midsole to the cavity.

It should be noted, however, that even with the conventional hollow core tile technique, the invention can improve sound attenuation and produce smooth, machined floor surfaces when the surface tile is made of machined aerated concrete and the hollow slab cavities are joined to the elastic portion 30 of the top surface hole.

Other details and advantages of the invention will become apparent from the following description, in which the invention is considered by means of the accompanying drawings.

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Figure 1 shows a partial cross-section of a building tile assembly according to the invention.

Figure 2 shows a side view of a building tile assembly.

Figures 3 and 4 show top views, partly in section, of two alternative building tile combinations.

Figure 5 shows a cross-section of a joint between two building tile assemblies.

Figure 6 shows a cross-section of a hollow plate assembly 5 made by means of a conventional hollow core slab.

The embodiment of the invention according to Figures 1 and 2 comprises an intermediate base plate 1, 2, on which a cover plate 3 is mounted on elastic spacers 4 so that an air gap 5 remains between the intermediate base plate 10, 1 and the cover plate 3.

The intermediate base slab 1, 2 is made of ordinary concrete and is formed with a cavity 6 parallel to the longitudinal axis of the slab, which extends from end to end of the slab. The lower half 15 2 of the slab, which forms the so-called tensile surface, is provided with prestressed shell tensions 7, 8 which run in the longitudinal direction of the slab. The shell tendons consist of prestressing steels 7 and the surrounding shell parts 8 made of hard concrete. Openings 9 are formed in the upper part of the slab, i.e. in the pressing part 1, at the cavity 6, connecting the air space 5 between the slab and the surface plate to the cavity 6. Longitudinal dowels 10 are formed at the edges of the lower half of the midsole. - every 70 cm) thinnings 11.

25 From these points, the edges of the slab can be pierced, for example, for water and sewer penetrations.

In the structure shown, the air space between the cover plate 3 and the midsole 1, 2 is connected to the central cavity of the midsole, which reduces the rigidity of the air layer. Together, the expanded air space of the elastic spacers forms a spring combination that effectively dampens sounds.

The midsole plate is produced, for example, by ordinary molding technology 35 by first casting a low U-shaped lower half 2, turning it upside down and connecting it to the upper half 1. The joining of the upper and lower halves of the intermediate base plate can be carried out, for example, by bolted joints.

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The lower half casting mold has ready-made reserves for future edge reliefs 11 on the tiles.

According to one embodiment, the upper half 1 is made in the same mold as the lower half 2, whereby both halves are essentially identical. After assembling the intermediate base, the openings 9 passing through the shell of the upper half 1 are then machined into the upper half 1 of the slab at the cavity 6 formed in the intermediate base. They can be obtained, for example, by drilling. 10 This option is also suitable for use in the event that the sound insulation capacity of the subfloor or wall structure of an already completed building is subsequently improved (renovation work).

However, according to a preferred embodiment of the invention, the openings 9 are already produced in the casting stage by casting the upper half 1 of the midsole in a mold with recess molds for the openings. Preferably, the same mold is used as in the casting of the lower half, to which, however, loose cavity molds are fitted. However, it is also possible to use a mold with fixed cavity mold parts. Since the shell thickness of the lower half 2 of the midsole is greater than the corresponding thickness of the upper half, the lower half can also be cast in such a mold without its strength properties being significantly affected.

The cavities 9 may be rectangular or round in cross-section and arranged in one, two or more rows, as shown in Figures 3 and 4. The proportion of their areas in the total area of the slab can vary within wide limits depending on the strength requirements of the subfloor. Usually, however, the area of the openings 30 is about 10 to 50% of the surface of the slab.

The upper surface of the midsole 1, 2 is then provided with spacers 4 made of a suitable flexible material at suitable intervals. The spacers may consist of natural polymers or synthetic polymers. Examples of manufacturing materials include natural rubber, polyisoprene, polyurethane, polystyrene and various polyolefins. Preferably, expanded rubber or plastic materials (cellular plastics or rubbers) are used. However, spacers may also ίο S 9 393 consist of mechanical springs, such as the corrugated steel sheets described below. The spacing of the spacers depends on the dimensions of the slab and their material. Typically, however, they are installed at intervals of about 40 to 70 cm.

5 On the upper surface of the midsole, steel plates supported by the upper half 1 of the midsole are arranged between the flexible spacers 4, which form a planar casting base on their upper surface. To increase the rigidity of the steel plates, they can be provided with corrugations.

10 A layer of concrete a few centimeters thick is then poured on the steel plates and spacers to form a cover plate 3. Any suitable concrete mass can be used for casting. However, since the cover slab does not act as a load-bearing structure, it is preferable to make it from the lightest possible material, such as aerated concrete.

In a preferred embodiment of the invention, in which the upper half 1 is cast in a mold of the lower half, in which separate cavity molds are arranged, the casting of the cover plate is carried out in the same mold as the casting of the upper half 1. This solution has the advantage that the molds act as support members for the steel plate during casting. Separate formwork edges are also not required.

Alternatively, especially if the openings in the upper surface of the midsole are machined separately, as is necessary to improve the sound insulation of the old structure, special support members, such as corrugated steel plates, supporting the steel plates can be arranged between the steel plates and the upper surface of the midsole. Because such corrugated sheets are flexible, they interact with flexible spacers, or may function as such, if necessary. The support members may be separate from or permanently connected to the steel plates. In this embodiment, separate mold edges are placed against the edges of the upper half of the midsole for the casting of the cover plate 35.

In both embodiments, the mold is disassembled after casting and the cover plate 3 is machined to exactly the same size as the midsole plate.

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Figure 2 shows a cross-section of the joint of two slab assemblies according to the invention. As can be seen from the figure, the slab combinations 1, 2, 3 can be precisely matched thanks to the machining. During installation, dowels 12 made of plastic or wood material are arranged in the above-mentioned dowel grooves 5 in order to hold the tiles in place in a vertical plane.

The seams between the lower halves 2 of the midsoles can be covered with fiberglass tape 13 and a filler.

10 After installing the midsole, the desired floor covering, such as parquet or plastic mat, can be applied to the cover plate.

A hollow core slab assembly as described above was prepared with a total thickness of 30 cm and a span of 6 m. Vertical openings were then formed in the upper surface of the load-bearing hollow core slab (thickness 26 cm) extending up to the slabs of the slab. Rectangular openings accounted for 30% of the top surface of the slab. At regular intervals (approximately 50 cm), 20 flexible pieces were placed around the openings and a 3 cm thick surface tile made of aerated concrete was placed on top of these. The flexible pieces were made of cellular plastic and had a thickness of 1 cm. Another 1 cm parquet layer was installed on top of the surface tile.

25 In the performed measurements, the value of the step sound level L „w <55 dB was obtained with the mentioned proportion of sound openings. The load-bearing capacity of the slab combination was in line with the standards.

Figure 6 shows a slab assembly 21, '30 22 according to the invention implemented with a conventional hollow core slab structure. The midsole here consists of a single part 21, e.g. made by sliding molding, with a plurality of adjacent elongate cavities 23 having a circular or nearly circular cross-section. Openings 24 extending up to the hollow slabs 23 are formed in the upper surface of the hollow plate, as shown in Fig. 7. The openings 24 may be round or angular in cross section. The hollow core slab is reinforced with steels 26.

According to the previous embodiment, flexible spacers 25 and a cover plate 22 are arranged on the hollow plate 21 and an air space 27 is left between the cover plate 22 and the hollow plate 21.

5 This embodiment also provides effective sound attenuation in the slab structure. At the same time, it should be noted that the presented embodiment is particularly well suited for implementation in buildings undergoing renovation. In these locations, the sound insulation of the original hollow core slab bases can be improved during floor repair by drilling openings in the slabs that extend to the cavities. Flexible slabs and flat steel plates are then installed on the tiles and a concrete surface layer is cast on top of these.

Within the framework of the invention, solutions deviating from the above can also be considered. Thus - as already stated in the general part of the description - the invention can be applied to improve the sound insulation of walls. In this case, a slab according to Figures 1-5 or a similar hollow slab 20 is installed as the wall structure. Holes extending into the cavity are drilled in the slab, after which wall plates are mounted on each side of the slab, which are kept at a distance from the wall slab by means of flexible pieces. In the case where the beam acts as the load-bearing structure of the wall, a tile in the form of a housing with thinner edges can also be used as the wall tile.

When the tile combination according to the invention has cover or wall plates on both sides of the hollow core, it is advantageous to arrange the openings in the hollow core so that they do not collide in the transverse plane, which could impair the strength of the hollow core.

Claims (16)

A method of improving the sound insulation capability of a hollow space provided building plate (1,2, 21), according to which a method is provided at least one flat material layer (3; 22) and the space (5) from the surface of the hollow space provided building plate (5). ; 27) between the material layer (3; 22) and the building plate (1, 2; 21) are provided intermediate pieces (4; 25) of substantially resilient material (4; 25) which separate the material layer and the building plate, the air in that space (5). ; 27) which extends between the material layer (3; 22) and the building plate (1, 2; 21) together with the intermediate pieces (4; 25) of resilient material to form a spring combination which attenuates the sounds that pass through the building plate, characterized in that 20. the gap (5; 27) is joined to the heel space (6; 23) of the building plate to improve the sound-damping ability of said spring combination. Method according to claim 1, characterized in that the gap (5; 27) is joined to the heel space (6; 23) via openings (9; 24) which are received in the shell of the building plate, the area of said openings being about 10 - 50% of the area of the building plate (1, 2; 21) on the side of the material layer and wherein the opening-free portion of the building plate functions as a structural part. Method according to claim 2, characterized in that the openings (9) are received in the building plate (1, 2) in connection with the casting. 35 Method according to claim 2, characterized in that the openings (9; 24) are received by machining the cured building plate (1, 2; 21). 17 39398 5. Building plate combination with good sound insulation ability, comprising a first building plate (1, 2; 21), which at least exhibits a longitudinal heel cavity (6; 23), 5 - at least a second building plate (3; 22), which is arranged at a distance from the first building plate to form a gap (5; 27) between the building plates; and - spacers (4; 25) located between the first and the second plate and which are made of a resilient material and pours the first and second building plates separate from each other, the air in the space (5; 27) being raised upwardly between the material layer (3; 22) and the building plate (1,2; 21) together with the resilient intermediate pieces ( 4; 25) forms a spring combination which attenuates the sounds that pass through the building plate, characterized by openings (9; 24) which are included in the first building plate (1, 2; 21) and which extend from the space between the first and d a second building plate for the heel space (6; 23) in the first building plate for joining the gap with the heel space to improve the spring-damping ability of the spring combination. 6. The building plate combination according to claim 5, characterized in that the first building plate (1, 2) consists of two halves which in cross section show the shape of a positioned U and which are joined to each other at the tips of the branches of the U to form a central hollow space. (6), wherein openings 30 (9) passing through the respective half of the plate are recorded in the half of the meal located on the idle of the second building plate (3). Building plate combination according to claim 5, characterized in that the first building plate (21) consists of a conventional heel plate, which has a plurality of adjacent heel spaces (23) running in the longitudinal direction of the plate from one end of the plate to the other. the plate has openings (24) which are accommodated in at least one of its surfaces and which extend into said hollow space. Building plate combination according to any of claims 5 to 7, characterized in that it is prefabricated by machining the second building plate (3; 22) to exactly the same dimension as the first building plate (1, 2; 21). Building plate combination according to any of claims 5 - 10 8, characterized in that the second building plate (3; 22) is made of cellular concrete. Building plate combination according to any of claims 5 to 9, characterized in that it has two other building plates (3; 22), one on each side of the first building plate (1, 2; 21), and that openings (9; 24) extending from the gap to the cavity are accommodated on each side of the first building plate, said apertures being arranged incrementally so that the apertures on each side of the plate do not face each other. Building plate combination according to any of claims 5 to 8, characterized in that the intermediate pieces (4; 25) consist of a natural polymer, a synthetic polymer or of a mechanically resilient material. The building plate combination according to any of claims 5-11, whose openings are provided in connection with the casting of the first building plate, characterized in that the openings (9) are substantially rectangular in cross section. The building plate combination according to any of claims 5-11, whose openings are obtained by machining a hardened building plate, characterized in that the openings 35 are (9) of the cross-section substantially circular. The building plate combination according to any of claims 5-13, characterized in that the second plate (3; 22) is molded on a support plate which rests against the first plate.