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Title:
RUBBER-AGGREGATE COMPOSITIONS FOR SOUND ATTENUATION
Document Type and Number:
WIPO Patent Application WO/2017/137980
Kind Code:
A1
Abstract:
The present disclosure concerns particulate compositions of matter based on rubber and aggregate for attenuation of sound.

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Inventors:
MARIAN, Dan (23 Ha'Avoda St, 23 Binyamina, 3054423, IL)
BOGNER, Arie (36 Nurit St, 44 Haifa, 3465444, IL)
BEN AMI, Sharon (8 Yaara St, 08 Ramat Gan, 5264608, IL)
BEN BASSAT, Mony (5 Golda Meir St, 05 Haifa, 3498205, IL)
Application Number:
IL2017/050147
Publication Date:
August 17, 2017
Filing Date:
February 07, 2017
Export Citation:
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Assignee:
ACOGUM LTD. (36 Nurit Street, 45 Haifa, 3465445, IL)
International Classes:
E04B1/82; C04B18/22; E04F15/20; C04B111/52; C04B111/60
Domestic Patent References:
2003-05-01
2006-03-16
1994-12-08
Foreign References:
US5391226A1995-02-21
CA2241039A11999-12-19
EP2374969A12011-10-12
US5916681A1999-06-29
US20140308077A12014-10-16
KR101035512B12011-05-20
CN101746994A2010-06-23
Other References:
KOKADI; GANDOMAN, IRAN. J. POLYM., vol. 24, 2015, pages 105
Attorney, Agent or Firm:
BENSHAFRUT, Ronnie (Reinhold Cohn And Partners, P.O.B, 61131 Tel Aviv, 61131, IL)
Download PDF:
Claims:
CLAIMS:

1. A composition in particulate form comprising polymeric particles and aggregate particles, wherein the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and 35:65 and the composition having ALw greater than zero at a sound frequency below 100Hz.

2. The composition of claim 1, wherein the polymeric particles having an average particle size of between 0.1 and 15 mm.

3. The composition of claim 1 or 2, wherein the aggregate particles having an average particle size of between 1 and 20 mm.

4. A composition in particulate form comprising polymeric particles and aggregate particles, wherein the polymeric particles having an average particle size of between about 0.1 and 15 mm, and the aggregate particles having an average particle size of between about 1 and 20 mm, the composition having ALw greater than zero at a sound frequency below 100Hz.

5. The composition of claim 4, wherein the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and 35:65.

6. The composition of any one of claims 1 to 5, wherein the polymeric particles are made of a polymeric material selected from the group consisting of rubber, vulcanized rubber, siliconic rubber, foamed polymers and mixtures thereof.

7. The composition of claim 6, wherein said at least one polymeric material is selected from natural rubber, synthetic rubber, vulcanized rubber and mixtures thereof.

8. The composition of any one of claims 1 to 7, wherein the aggregate is selected from the group consisting of natural stone, recycled building materials, and concrete.

9. The composition of any one of claims 1 to 8, comprising at least one additive.

10. The composition of any one of claims 1 to 8, consisting of said polymeric particles and said aggregate particles.

11. The composition of any one of claims 1 to 10 for use in building constructs.

12. A composition in particulate form for use in building constructs, the composition having a ALw greater than zero at a sound frequency below 100Hz and comprising polymeric particles, said polymeric particles optionally having an average particle size of between about 0.1 and 15 mm, the polymeric particles comprise at least one polymeric material selected from natural rubber, synthetic rubber, vulcanized rubber and mixtures thereof.

13. The composition of claim 12, further comprising aggregate particles, said aggregate particles optionally having an average particle size of between about 1 and 20 mm.

14. A composition for use in building constructions, the composition being in particulate form and comprising polymeric particles and aggregate particles, wherein the weight ratio between the polymeric particles and the aggregate particles is between 2:98 and 35:65, the polymeric particles comprise at least one polymeric material selected from natural rubber, synthetic rubber, vulcanized rubber, and mixtures thereof, the composition having ALw greater than zero at a sound frequency below 100Hz.

15. The composition of claim 14, wherein the polymeric particles having an average particle size of between 0.1 and 15 mm.

16. The composition of claim 14 or 15, wherein the aggregate particles having an average particle size of between 1 and 20 mm.

17. A composition for use in building constructions, the composition being in particulate form and comprising polymeric particles and aggregate particles, wherein the polymeric particles having an average particle size of between 0.1 and 15 mm, and the aggregate particles having an average particle size of between 1 and 20 mm, the polymeric particles are made of a polymeric material selected from the group consisting of natural rubber, synthetic rubber, vulcanized rubber, and mixtures thereof, the composition having ALw greater than zero at a sound frequency below 100Hz.

18. The composition of claim 17, wherein the weight ratio between the polymeric particles and the aggregate particles is between 2:98 and 35:65.

19. A composition for use in building constructions, the composition being in particulate form and comprising polymeric particles and aggregate particles, wherein the weight ratio of the polymeric particles to the aggregate particles is adapted to a ALw greater than zero when at a sound frequency below 100Hz, the polymeric particles are made of a polymeric material selected from the group consisting of natural rubber, synthetic rubber, vulcanized rubber, and mixtures thereof.

20. A composition for use in building constructions, the composition being in particulate form and consists of polymeric particles and aggregate particles, wherein the weight ratio of the polymeric particles to the aggregate particles is adapted to a ALw greater than zero when at a sound frequency below 100Hz.

21. The composition of claim 20, wherein the polymeric particles are made of a polymeric material selected from the group consisting of natural rubber, synthetic rubber, vulcanized rubber, and mixtures thereof.

22. A composition of any one of claims 1 to 21 for use in attenuating sound.

23. A sound attenuation article comprising the composition of any one of claims 1 to 21.

24. The composition of claim 22 or article of claim 23, wherein the attenuated sound is solid-borne sound.

25. A method of attenuating sound in building constructs, comprising applying the composition of any one of claims 1 to 21 to a surface of an enclosure of the building requiring sound attenuation.

26. A method of attenuating sound in building constructs, comprising:

(a) mixing polymeric particles and aggregate particles to form a composition in particulate form according to any one of claims 1 to 21; and

(b) applying the particulate composition to a surface of an enclosure of the building that requires sound attenuation.

27. The method of claim 26, wherein the polymeric particles having an average particle size of between about 0.1 and 15 mm.

28. The method of claim 26 or 27, wherein the aggregate particles having an average particle size of between about 1 and 20 mm.

29. The method of any one of claims 26 to 28, wherein said sound attenuation is characterized by ALw greater than zero at a sound frequency below 100Hz.

30. The method of any one of claims 26 to 29, wherein the polymeric particles comprise at least one polymeric material selected from natural rubber, synthetic rubber, vulcanized rubber and mixtures thereof.

31. The method of any one of claims 26 to 30, wherein said mixing is carried out by a rotating drum, manual mixing, an auger, a screw-conveyer, and a pressurized-air mixer.

32. The method of any one of claims 26 to 31, wherein said surface is a ceiling or a floor frame of said building construct.

Description:
RUBBER-AGGREGATE COMPOISITIONS FOR SOUND ATTENUATION

TECHNOLOGICAL FIELD

The present disclosure concerns particulate compositions of matter based on polymeric material, e.g. rubber, and aggregate for attenuation of sound.

BACKGROUND ART

References considered to be relevant as background to the presently disclosed subject matter are listed below:

[1] Canadian patent publication no. CA 2,241,039

[2] European patent publication no. EP 2374969

[3] US patent no. 5,916,681

[4] US application publication no. 2014/308077

[5] PCT application publication no. WO 06/027634

[6] PCT application publication no. WO 94/27800

[7] Korean patent publication no. KR 10- 1035512

[8] Chinese patent publication no. CN 101746994

[9] Kokadi & Gandoman, Iran. J. Polym. 2015, 24, 105

Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

BACKGROUND

Sound transmission is of major concern in the construction industry. More specifically, sound transmittal between floors of a building through the ceiling/floor (i.e. solid-borne sound) has proved to be one of the significant contributors to noise- pollution and nuisance to inhabitants. Thus, when constructing a new building, attention should be given to incorporation of means for reducing or eliminating solid-borne sounds.

The problem of solid-borne sound is of greater magnitude in construction methods based on poorly sound-insulating materials such as concrete and aggregate. In many countries construction is based on constructing a reinforced concrete frame, typically by casting, onto which other construction materials are applied. For example, the floor is typically constructed out of a cast or pre-cast concrete base, onto which a layer of particulate or granular loose filler is layered. The filler layer functions both as a base for easy leveling of the flooring tiles (or any other type of rigid flooring), and also provides a workable layer into which infrastructure elements (for example piping) may be installed. In order to reduce costs of construction, aggregate (namely, crushed natural stone) is typically used. Although aggregate has beneficial properties as a filler material, it is a poor sound attenuator, through which sound is easily carried between the building's floors.

A common solution to the sound attenuation problem is the application of a sound-insulating polymeric sheet that is applied between the concrete base and the filler layer. The sound-insulating polymeric sheet is applied onto the concrete base, and infrastructure elements (such as installation pipes, mechanical and electrical systems, etc.) are installed. After completion of the installation, the filler is added in order to form a workable substrate for the flooring. Sound attenuation is impacted by the quality of layering of such sheets and their integrity, and thus, poor sound attenuation often results from improper installation of the polymeric sheet or damage caused to it due to the infrastructure installation process.

Another suggested solution is the use of cast insulating layers, such as cement mixed with aggregate and rubber. Such compositions are usually prepared on-site, similar to the process of preparing cement-based compositions, and are cast in a wet state onto the concrete frame base, and then left to cure and form a cast, continuous layer. Such solutions require the use of special compositing and casting equipment, such as mixers and special pumps for application. In addition, care should be given to the quality of the casting, as the top layer should be leveled (before curing) in order to provide a leveled foundation for the flooring tiles. A similar proposed solution is the use of polymer-aggregate compositions, in which the aggregate is mixed into a polymer melt and then spread or cast over the concrete frame-base. After casting, the polymer is left to cure or harden, forming a continuous polymeric matrix, with aggregate particles distributed therein. As a person of the art may appreciate, similar disadvantages apply in such solutions.

Thus, there is a need for a solid-borne sound-attenuation composition which may be easily applied, easily leveled, serve as a filler layer into which infrastructure elements can be easily fitted, simple to produce, as well as relatively inexpensive.

GENERAL DESCRIPTION

The inventors of the present invention have come to the realization that mixing polymeric particles into the aggregate commonly used in the construction industry results in a filler composition in particulate form that enables easy application and leveling, forms a loose enough base for easy infrastructure installation, as well as provides standard- acceptable, at time even improved, sound attenuation.

Thus, in one aspect, the present disclosure provides a sound-attenuating composition in particulate form comprising polymeric particles and aggregate particles, wherein the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and 35:65.

The compositions of this disclosure are provided in particulate form, namely as a mixture of distinct polymeric particles and distinct aggregate particles, mixed together to a substantially homogenous mixture of particles. Maintaining the compositions in such particulate form provides the building constructor with flexibility of utilization and ease of application. In addition, the loose form of the composition enables easy leveling before and during application of the other flooring layers.

In some embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and about 35:65. In other embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 3:97 and about 35:65. In some other embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 4:96 and about 35:65.

In further embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 5:95 and about 35:65. According to some embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and about 30:70. According to other embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and about 27:73. According to some other embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and about 25:75.

In yet other embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 3:97 and about 27:73. In additional embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 5:95 and about 25:75.

The term polymeric particles means to denote particles made of one or more polymer-based materials. Suitable polymeric materials to carry out the invention are typically elastomers synthetic or of natural origin. In some embodiments, the polymeric material may be selected from natural rubber, synthetic rubber, vulcanized rubber, silicon-based rubber, foamed polymers, polyurethane and foamed polyurethane, polystyrene and foamed polystyrene, or any other suitable polymeric material, and any combination or mixture thereof.

In other embodiments, the polymeric material may be selected from natural rubber, synthetic rubber, vulcanized rubber and any combination or mixture thereof.

In other embodiments, the polymeric particles are crushed or shredded rubber (or vulcanized rubber) particles. According to some other embodiments, the crushed or shredded rubber is crushed or shredded rubber from recycled tires.

In some embodiments, the synthetic rubber may be selected from polyacrylate rubbers, ethylene-acrylate rubbers, polyurethanes, polyester urethanes, polyether urethanes, styrene-butadiene copolymers, bromo (or chloro)-isobutylene-isoprene copolymers, polybutadiene rubber, polychloroprene rubber (neoprene), chlorosulphonated polyethylene (Hypalon™), epichlorohydrin rubber, ethylene propylene, ethylene -propylene diene monomer (EPDM), perfluorocarbon rubber, fluorinated hydrocarbons (such as Viton® or Fluorel®), polysiloxane rubbers, silicon rubbers, fluoro silicone rubbers, fluorocarbon rubbers, hydrogenated nitrile butadiene, polyisoprene, isobutylene-isoprene butyl copolymer, acrylonitrile butandiene rubber, or any other elastomeric polymer, and any mixture or copolymer thereof. The term "polymer" includes homopolymers, copolymers, for example, block, graft, random and alternating copolymers as well as terpolymers, further including their derivatives, combinations and blends thereof. In addition to the above the term includes all geometrical configurations of such structures including linear, block, graft, random, alternating, branched structures, and combination thereof.

According to some embodiments, the suitable polymeric materials are such having hardness of between about 40 and 100 Shore A. In other embodiments, the polymeric materials may be characterized by hardness of between about 40 and 75 Shore A.

In accordance with some embodiments, the polymeric particles may have an average particle size of between about 0.1 and 15 mm. In the context of the present invention, the term average particle size refers to the arithmetic mean of measured diameters, wherein the diameters range +25% of the mean. In particles which are not spherical, the average size is calculated as an arithmetic mean of the equivalent diameters of the particles.

In some embodiments, the polymeric particles may have an average particle size of between about 0.1 and 13 mm, between about 0.1 and 11 mm, between about 0.1 and 10 mm, between about 0.1 and 9 mm, between about 0.1 and 8 mm, between about 0.1 and 7 mm, between about 0.1 and 6 mm, or even between about 0.1 and 5 mm.

In other embodiments, the polymeric particles may have an average particle size of between about 0.2 and 15 mm, between about 0.3 and 15 mm, between about 0.4 and 15 mm, or even between about 0.5 and 15 mm.

As a person of the art would appreciate, the polymeric particles may be obtained by any suitable process, such as cutting, jet-cutting, crushing, shredding, melt-casting, spray drying, etc. The polymer particles may be at any shape and form, symmetrical or non-symmetrical; non-limiting examples are beads, flakes, rods, cubes, etc. After rubber particles are obtained, the rubber particles may be separated into distinct size fractions, used as is or re-mixed to obtain the desired average particle size and size distribution.

The term aggregate particles refer to natural stone, queried and crushed/cut into distinct particles. The natural stone may be any suitable stone known to a person of skill in the art, including limestone, sandstone, granite, dolomite, Jerusalem stone, marble, slate, flint, travertine, or any other natural quarried stone, and any combination or mixture thereof. In the context of the present disclosure the term aggregate also encompasses recycled concrete or a mix of recycled construction materials (such as cement-based products, concrete blocks, etc.), i.e. recovered from building and/or demolition sites, crushed or processed into particles of suitable size.

In some embodiments, the aggregate particles may have an average particle size of between 1 and 20 mm.

According to other embodiments, the aggregate particles may have an average particle size of between about 1 and 18 mm, between about 1 and 16 mm, between about 1 and 14 mm, between about 1 and 12 mm, between about 1 and 10 mm, between about 1 and 8 mm, between about 1 and 6 mm, or even between about 1 and 5 mm.

The aggregate particles may be obtained by any method known in the art. Non- limiting examples may be crushing, grinding, water-cutting, milling, etc. After particles are obtained, the aggregate particles may be separated into distinct size fractions, used as is or re-mixed to obtain the desired average particle size and size distribution.

The combination of the polymeric particles and the aggregate particles provides for the formation of a composition which, in some embodiments, has a ALw value greater than zero (ALw > 0), at a sound frequency below 100Hz. ALw is the difference between the measured sound (in decibels, dB) of an impact exerted on a reference sample and the measured sound (in dB) of an identical impact exerted on a tested sample. Namely, when the tested sample attenuates sound, the sound intensity of an exerted impact will be smaller than the sound measured for the same impact exerted on a reference sample. Thus, a positive ALw denotes sound attenuation, while a negative ALw denotes sound amplification. In the context of the present disclosure the value of ALw is determined according to the tests and calculation methods of international standards ISO-10140-3 (2013) and ISO-717-2 (2013), as exemplified hereinbelow.

The compositions of the present disclosure are characterized by positive ALw at sound frequencies of below 100 Hz; i.e. the compositions of the present disclosure attenuate sound at frequencies below 100 Hz.

It is of note that most of the common insulation solutions provide good sound insulation/attenuation at high frequencies (typically above 100 Hz). However, low frequency solid-borne sound (such as footsteps) is often not dealt with and is a major component is sound-pollution in residence buildings. It is also of note that common sound attenuation solutions, although providing satisfactory sound attenuation of high frequency sounds, often show amplification of low frequency sounds. The compositions of the invention, as will be shown below, provide for sound attenuation for both high and low frequency sounds.

In another one of its aspects, this disclosure provides a composition in particulate form comprising polymeric particles and aggregate particles, wherein the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and 35:65 and the composition having ALw greater than zero at a sound frequency below 100Hz.

In some embodiments, the polymeric particles having an average particle size of between about 0.1 and 15 mm, and/or the aggregate particles having an average particle size of between about 1 and 20 mm.

In another aspect, the disclosure provides a composition in particulate form comprising polymeric particles and aggregate particles, wherein the polymeric particles having an average particle size of between about 0.1 and 15 mm, and the aggregate particles having an average particle size of between about 1 and 20 mm, and the composition having ALw greater than zero at a sound frequency below 100Hz.

In some embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and 35:65.

Another aspect of this disclosure provides a composition in particulate form comprising polymeric particles and aggregate particles, wherein the weight ratio of the polymeric particles to the aggregate particles is adapted to a ALw greater than zero at a sound frequency below 100Hz.

In some embodiments, the weight ratio between the polymeric particles and the aggregate particles is between about 2:98 and 35:65.

In other embodiments, the polymeric particles having an average particle size of between about 0.1 and 15 mm. In some other embodiments, the aggregate particles having an average particle size of between about 1 and 20 mm.

Compositions of this disclosure, by some embodiments, may comprise at least one additive. Said at least one additive may modify one or more of the properties of the composition, as long as the desired sound attenuation is maintained at the desired level. Non-limiting examples of such additives may include additional particulate fillers, flowability modifiers, powdered pigments, etc.

By some embodiments, the compositions of the present disclosure consist of polymeric particles and aggregate particles. Namely, in some embodiments, the compositions of the invention consist of one or more type of polymeric particles and one or more types of aggregate particles, without any additional components.

Another aspect of the disclosure provides a composition in particulate form having a ALw greater than zero at a sound frequency below 100Hz, said composition comprising polymeric particles. In some embodiments, such compositions may further comprise aggregate particles.

In some embodiments, the polymeric particles may comprise at least one polymeric material selected from natural rubber, synthetic rubber, vulcanized rubber and mixtures thereof.

In another aspect, the disclosure provides a composition in particulate form having a ALw greater than zero at a sound frequency below 100Hz, said composition comprising aggregate particles. In some embodiments, the composition may further comprise polymeric particles, which may comprise at least one polymeric material, optionally selected from natural rubber, synthetic rubber, vulcanized rubber and mixtures thereof.

The compositions of this disclosure may be used as in building constructs; namely for attenuating sound in a building construct.

Thus, on another aspect, there is provided a composition as described herein for use in building constructs.

Another aspect of the present disclosure provides a composition as described herein for use attenuating sound, typically in building constructs.

Attenuating sound refers to reduction of sound wave amplitude, absorbance and/or dissipation of sound at desired frequencies, insulation by reflection of sound waves, etc., providing for a reduction in transmission sound, typically of solid-borne sounds. In some embodiments, the attenuated sound is solid-borne sound.

The term building construct means to denote any type of building (construction) having at least one surface through which sound may be transmitted. For example, the building construct may be a residential building, an apartment in a residential building, an office building, a room in a building, an industrial building, a shed, a transportable unit, a pre-cast unit, etc. The building construct typically has at least one surface tonto which the compositions described herein may be applied; a floor or a ceiling (horizontal surfaces), or hollow wall sections that may be filled with the composition (vertical surfaces) are non-limiting examples of such surfaces.

In some embodiments, the composition is used in attenuation of sound between floors of a building.

A further aspect provides a sound attenuation article comprising the composition as herein described.

In some embodiments, the article may be selected from loose particulate composition (e.g. for use as a base layer for tiling or flooring), a flooring block or tile comprising the particulate composition (e.g. a box-shaped frame filled with the loose particulate composition), etc.

In another aspect, there is provided a method of attenuating sound, comprising applying a composition as herein described to a surface of an enclosure of a building that requires sound attenuation.

In yet another aspect, the disclosure provides a method of attenuating sound in building constructs, comprising:

(a) mixing polymeric particles and aggregate particles to form a composition in particulate form; and

(b) applying the particulate composition to a surface of an enclosure of a building that requires sound attenuation.

In some embodiments, the weight ratio between the polymeric particles and the aggregate particles in the composition is between about 2:98 and 35:65. In other embodiments, the polymeric particles having an average particle size of between about 0.1 and 15. In some other embodiments, the aggregate particles having an average particle size of between about 1 and 20 mm. In further embodiments, said sound attenuation is characterized by ALw greater than zero at a sound frequency below 100Hz.

In some embodiments, the polymeric particles comprise at least one polymeric material selected from natural rubber, synthetic rubber, vulcanized rubber and mixtures thereof. According to some embodiments, the mixing of the polymeric particles and the aggregate particles may be carried out by manual mixing, a rotating drum, an auger, a tumbler, a mixing pedal, screw-conveyer, mixing by pressurized air, or any other suitable means known perse. Application of the composition (i.e. layering onto the surface to be treated) may be carried out manually, or assisted by a suitable pumping and distribution means adapting for matter in particulate form.

According to some embodiments, the method may further comprise compacting the composition after its application. It is noted that in the contexts of the present disclosure, compaction refers to mechanical compaction (namely reducing the amount of air voids between the particles by mechanical means, such as tapping, compressing, etc.). The compaction does not involve any chemical or thermal activation; meaning that reducing the volume of voids between the particles is not obtained by melting and flowing of the polymeric material, chemical activation of cementations additives, etc.

According to other embodiments, the method may further comprise leveling the composition after application (whether compaction has been carried out or not), i.e. prior to installing the next flooring layers.

In some embodiments, the surface to be treated by employing the application method of this disclosure is a ceiling or a floor frame of a building.

As used herein, the term "about" is meant to encompass deviation of +10% from the specifically mentioned value of a parameter, such as temperature, pressure, concentration, etc.

Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range, i.e. includes the first and second indicated numbers and all the fractional and integral numerals therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Fig. 1 shows sound attenuation (ALw vs. sound frequency) of aggregate.

Fig. 2 shows sound attenuation (ALw vs. sound frequency) of a commercial foamed polymeric sheet.

Figs. 3A-3B show sound attenuation (ALw vs. sound frequency) for different compositions of the present disclosure: 10 wt% rubber from recycled tires in limestone aggregate, aggregate size of 0.5-2mm (Fig. 3A) and aggregate size of below 0.5 mm (Fig. 3B).

Fig. 4 shows sound attenuation (ALw vs. sound frequency) for a composition of the present disclosure: 11 wt% rubber from recycled tires in limestone aggregate, aggregate size of 4.75-9.3 mm.

DETAILED DESCRIPTION OF EMBODIMENTS

The sound attenuation of the compositions of this disclosure was tested according to international standard ISO 10140-3 (Acoustics - Laboratory measurement of sound insulation of building elements - Part 3: Measurement of impact sound insulation 2013). Calculations of ALw were carried out according to international standard ISO 717-2 (Acoustics - Rating of sound insulation in buildings and of building elements - Part 2: Impact sound insulation, 2013). In brief, this test protocol measures the sound attenuation of impact (typically -100 KPa) exerted on the tested sample. The sound attenuation is measured by microphones over a frequencies' range of 100-5000 Hz.

In all measurements, concrete flooring was used to obtain the reference measurement. For measuring the sound attenuation of compositions of this disclosure, the following samples construction was used: a 150 mm deep wooden frame (area 0.8 m 2 ) was filled with 120 mm of the tested composition. A 20 mm layer of mortar was leveled above the tested composition, and 10 mm thick porcelain tiles were positioned. The spacing between the tiles was filed with grout. The samples were left to cure for 24 hours before carrying out the test.

Fig. 1 shows sound attenuation measurements of limestone aggregate sample comprising aggregate particles of 2.5-9.3 mm in size, without polymeric particles. This simulated the typical flooring structure used in standard building today. As can be seen from Fig. 1, sound attenuation is obtained for frequencies of between -315-5000 Hz. However, the data also revealed that below 315 Hz, the ALw of the aggregate sample has negative values. Namely, sounds in frequencies below 315 Hz were amplified rather than attenuated, as is evident from the measurements data detailed in Table 1.

Table 1: ALw of aggregate sample

As can be seen, low-frequency sounds, which are typical to apartment buildings, are actually amplified by the aggregate layer.

As noted above, one of the solutions available in the marked today is the use of insulating polymeric sheets, that are typically applied underneath the aggregate layer (i.e. between the concrete frame of the floor and the aggregate filling). Shown in Fig. 2 is a measurement of the sound attenuation obtained for a sample containing (order of layers from the bottom- up): 140 mm concrete floor / 6 mm foamed polyethylene / 65 mm concrete slab. The test was carried out according to ISO 10140-3 and ISO 717-2, however with a sample set-up suitable for polymeric sheets. As can be seen, the insulation layer improves the sound attenuation for frequencies between 100-5000 Hz. Sound attenuation results for compositions of the present disclosure are shown in Figs. 3A-4. The tested compositions are show in Table 2.

Table 2: Tested rubber-aggregate compositions

Rubber particles obtained from recycled tires, having hardness of 50-70 S hore A.

The rubber-aggregate mixtures were obtained by blending the rubber particles into the aggregate particles until a substantially homogenous distribution of the rubber particles in the aggregate particles was obtained. The tested samples had the following configuration (order of layers from the bottom-up): 120 mm tested mixture / 20 mm mortar / 10 mm porcelain tiles.

The sound attenuation tests clearly show that the addition of the rubber particles allowed for obtaining sound attenuation at low frequencies (i.e. <100-125 Hz), rather than amplification of sounds at the same frequencies as obtained by using only aggregate. Moreover, when compared to the standard foamed polyethylene sheet, sound attenuation at low frequencies was obtained at frequencies below 100 Hz for the tested mixture samples, while the standard sheet showed no sound attenuation at 100 Hz.

The workability of the particulate composition of this disclosure was tested by preparation of 1350 Kg of a particulate composition, by mixing 10 wt% of shredded recycled rubber tires and 90 wt% of limestone aggregate with a size of 4.75-9.3 mm. The rubber and aggregate particles were mixed by hand, resulting in a substantially uniform distribution of the rubber particles in the aggregate. The prepared composition was applied onto a concrete substrate having a surface area of 10 m 2 , and leveling was easily carried out by hand prior to layering of mortar and tiles.

As a man of the art would appreciate, as compared to the common solutions available to date, compositions of the present disclosure allow obtaining standard- acceptable, and even improved, sound attenuation characteristics without losing the advantages of loose material fillers (such simplicity of application and ease of leveling).




 
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