Compositions for construction and products of manufacture therefrom

Abstract

The present disclosure concerns compositions for construction, as well as construction elements manufactured from the compositions, such as walls, bricks, panels, etc. The compositions are based on a combination of plaster particles, concrete particles and at least one polymer. The disclosure further concerns systems for constructing walls made from the compositions.

Description

[0001] Compositions for construction and products of manufacture therefrom

[0002] TECHNOLOGICAL FIELD

[0003] The present disclosure concerns compositions for construction and products manufactured therefrom. More specifically, the disclosure concerns compositions for manufacture of constructure elements, typically walls or panels.

[0004] BACKGROUND ART

[0005] References considered to be relevant as background to the presently disclosed subject matter are listed below:

[0006] - Patent application publication CN106957165

[0007] - Patent application publication CN102040362

[0008] - Patent application publication CN109796189

[0009] - Patent application publication ES2831123

[0010] - Patent application publication GB2460707

[0011] Patent application publication JP2020164355

[0012] 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.

[0013] BACKGROUND

[0014] Construction and demolition (C&D) waste poses a significant environmental hazard. According to recent US Bureau of Transportation statics, about 23% of the entire yearly waste stream of the United States is attributed to C&D solid waste (mainly concrete, which is estimated to account for 85% of C&D waste). It is estimated that construction and demolition waste accounted for 30-40% of the total solid waste stream globally in 2022, out of which more than 75% were sent to landfills and remained untreated. While attempts have been made to reclaim or recycle C&D waste, for example utilizing reclaimed plaster and concrete in the construction of new engineering elements (such as support posts, walls, bricks, etc.), the processes involved in such efforts often require utilization of fresh wet cement as binding material, requiring not only the use of additional cement but also long curing periods (a few days to a few weeks). Alternative processes require heating to high temperatures to obtain a desired mechanical integrity.

[0015] Therefore, there is a need for compositions, as well as simple and cost-effective processes of manufacture for preparing construction elements, such as walls, partitions, panels, etc., that would enable utilization of reclaimed or recycled C&D waste.

[0016] GENERAL DESCRIPTION

[0017] The present disclosure provides compositions for manufacturing of construction elements, such as walls, partitions, cladding panels, acoustic and / or thermal insulating panels, etc., having a major component thereof being processed recycled C&D waste, in particular plaster and concrete. The disclosure further provides construction elements made of such compositions, processes for their preparation, and construction systems which can utilize such elements.

[0018] The compositions and processes of this disclosure provide construction elements which are relatively simple and cost-effective to manufacture, that demonstrate improved mechanical properties compared to standard drywalls, as well as high acoustic and / or thermal insulating properties. Further, the construction elements have adequate mechanical and environmental properties, such that these can be used as partitions or walls without requiring internal reinforcement beams (unlike standard panels for construction of drywalls, which are limited in their size due to their poor mechanical properties).

[0019] According to one of its aspects, the disclosure provides a composition for manufacturing of a construction element, the composition comprising: at least 70 wt% of a mixture of plaster particles and concrete particles, and at least 10 wt% of a water-based polymeric emulsion.

[0020] By another aspect, there is provided a composition for manufacturing of a construction element, the composition comprising: at least 65 wt% of a mixture of plaster particles and concrete particles, at least 8 wt% of at least one polymer, and between about 15 wt% and 30% wt% water.

[0021] By yet another one of its aspects, there is provided a composition for manufacturing of a construction element, the composition comprising: at least 65 wt% of a mixture of plaster particles and concrete particles, at least 8 wt% of at least one polymer, at least one surfactant, and between about 15 wt% and about 30 wt% of water.

[0022] Within the context of the present disclosure, the term construction element is meant to refer to a solid constructional element, typically in a panel form, such as a drywall, a partition wall, a cladding panel, a cladding tile, an acoustic panel, a thermal insulating panel, a block, a brick, a ceiling board, etc. It is of note that while the construction panel is typically substantially planar, the disclosure contemplates also angled or curved panels, or panels having curved sections.

[0023] The term plaster refers to calcium sulfate-based minerals, known as gypsum or ceramic gypsum minerals, e.g. plaster of Paris. According to some embodiments, the plaster is recycled or reclaimed plaster - e.g. plaster boards or panels recycled or reclaimed from construction waste, typically without having undergone chemical processing.

[0024] Concrete refers to cured, or substantially cured, cement-based composition typically utilized in construction. Concrete is typically obtained by hydraulic cementation processes of various types of cement, mainly comprising calcium oxide (CaO or quicklime), as well as various calcium silicate and calcium aluminate additives. The concrete can be made out of any type of construction-suitable cement, such as ASTM Cl 50 Type I Portland cement, ASTM Cl 50 Type II Portland cement, ASTM Cl 50 Type III Portland cement, ASTM Cl 50 Type IV Portland cement, ASTM Cl 50 Type V Portland cement, EN 197-1 Portland cement, EN 197-1 Portland composite cement, Blast furnace cement, Pozzolanic cement, and white Portland cement. According to some embodiments, the concrete is recycled or reclaimed concrete - e.g. concrete elements, such as walls, plates, tiles, columns, etc. recycled or reclaimed from construction waste, as well as cured or substantially cured leftover cement (for example from cement mixers or processing facilities). In the compositions of this disclosure, the plaster and concrete are utilized in particulate form to form a mixture of particles. The term particulate form refers to loose particles.

[0025] According to some embodiments, the mixture has an average particle size of no more than 500 pm (micrometers, microns), for example between about 50 pm and about 500 pm, between about 50 pm and about 400 pm, between about pm and about 300 pm or even between about 50 pm and about 250 pm.

[0026] According to some embodiments, the mixture has an average particle size of between about 100 pm and about 300 pm.

[0027] For utilizing recycled or reclaimed concrete and plaster, concrete and plaster waste is separated out of the construction waste, and then crushed, ground or pulverized to the desired particle size.

[0028] The term averaged particle size refers to the arithmetic mean of measured diameters of the particles. Where the particles are non-spherical, the term means to refer to the arithmetic mean of the diameter of imaginary spheres based on the longest measured dimension of the particles. Unless specifically indicated otherwise, the average particle size is determined by weight average.

[0029] By some embodiments, the weight ratio between the plaster particles and the concrete particles in the mixture is between about 1 : 10 and about 10: 1.

[0030] According to some embodiments, the mixture contains more concrete particles than plaster particles. By some embodiments, the weight ratio between the plaster particles and the concrete particles in the mixture is between about 1 : 1 and about 1 : 10.

[0031] According to other embodiments, the mixture contains more plaster particles than concrete particles.

[0032] According to some embodiments, the composition comprises between about 65 wt% and about 85 wt%, e.g. between about 70 wt% and about 85 wt%, of said mixture.

[0033] The compositions of this disclosure comprise at least one polymer, which can be in the form of a water-based polymeric emulsion. The term water-based polymeric emulsion refers to a colloidal dispersion or suspension of at least one polymer is an aqueous continuous phase.

[0034] Alternatively, the polymer can be in dry, powder form, and made to be water- dispersible by adding at least one surfactant to the composition. Mixing the polymer with at least one surfactant permits obtaining a water-dispersible polymeric mixture, enabling the polymer to be dispersed or emulsified in the water added to the composition.

[0035] It was found by the inventors that certain types of polymers, either in emulsion form or when made to be dispersible in water by addition of surfactants, provide superior mechanical properties compared to standard polymers used in construction, such as styrene-based polymers. Further, the inventors have found that when utilizing these water-based polymeric emulsions or water-dispersible polymeric mixture, a construction element having a desired porosity can be obtained, rendering the element with desired acoustic and thermal insulation properties, as will be described below.

[0036] According to some embodiments, the water-based polymeric emulsion is an aqueous emulsion of at least one polymer selected from vinyl acetate acrylic copolymer, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

[0037] In some embodiments, the water-based polymeric emulsion is a vinyl acetate acrylic copolymer aqueous emulsion.

[0038] In some embodiments, the water-based polymeric emulsion comprises at least 40 wt% of said at least one polymer, e.g. at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, or even at least 90 wt% of said polymer.

[0039] According to some embodiments, the water-based polymeric emulsion comprises between about 70 wt% and about 90 wt% of said at least one polymer.

[0040] In some embodiments, the composition comprises between about 10 wt% and about 30, wt% of said water-based polymeric emulsion, e.g. between about 15 wt% and about 25 wt% of said water-based polymeric emulsion.

[0041] According to some embodiments, the at least one polymer is selected from vinyl acetate acrylic copolymer, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

[0042] In some embodiments, the at least one polymer is a vinyl acetate acrylic copolymer aqueous emulsion.

[0043] In some embodiments, the composition comprises between about 8 wt% and about 30 wt% of said polymer, e.g. between about 10 wt% and about 25 wt% of said polymer. By some embodiments, the composition comprises said surfactant in an amount of no more than about 3 wt%.

[0044] By some embodiments, the composition comprises between about 20 wt% and about 30 wt% water.

[0045] According to some embodiments, when a water-based polymeric emulsion is used, the composition may comprise a total amount of water of between about 15 wt% and 30 wt% (i.e. water from the water-based emulsion together with additional water added to the composition).

[0046] Without wishing to be bound by theory, a limited chemical reaction occurs between the plaster and concrete particles and the water in the composition, causing a limited release of gaseous products (e.g. CO2) during drying of the composition to form the construction element. The inventors have found that in the compositions of this disclosure, the limited release of the gaseous products is sufficient to forms a polymeric matrix that is sufficiently porous to provide desired acoustic and / or thermal insulative properties.

[0047] The composition may include one or more functional additives to modify the properties of the construction element to be produced therefrom.

[0048] According to some embodiments, the composition comprises at least one blowing agent or foaming agent. Such blowing or foaming agents are compounds or formulations that at least partially decomposes into gaseous product(s) due to a chemical reaction with one or more of the components in the composition or when heated above their decomposition temperature. The blowing or foaming agents can be used to further modify the porosity of the construction element manufactured from the composition of this disclosure. The blowing or foaming agent may be present in the composition in an amount of between 0 wt% and about 5 wt%, e.g. up to about 3 wt%.

[0049] According to some embodiments, the composition comprises at least one flame retarding agent. The flame retarding agent is a compound or a formulation that provide one or more burning retardation effects, such as prolonging the time to ignition of the composition, reducing spreading of flames once ignited, self-extingui shing, etc. Non limiting examples of flame retarding agents are preferably halogen free, for example metal hydroxides such as aluminum tri-hydroxide (A1(OH)3), magnesium hydroxide (Mg(OH)2), and others. The flame retarding agent may be present in the composition in an amount of between 0 wt% and about 5 wt%, e.g. between about 1 wt% and about 5 wt%.

[0050] In some embodiments, the composition can further comprise one or more reinforcing materials, e.g. in fibrous form, to modify the mechanical properties of the construction element to be produced from the composition. Such reinforcing materials can be natural fibers (e.g. cotton fibers, hemp fibers, cellulose fibers, wool fibers, etc.) or synthetic fibers (for example metal fibers, carbon fibers, glass fibers, polymeric fibers, etc.). Preferably, the reinforcing materials are recycled or reclaimed reinforcing materials. The reinforcing materials may be present in the composition in an amount of between 0 wt% and about 15 wt%.

[0051] In some embodiments, the composition may further comprise one or more colorants, i.e. one or more pigments. Pigment or colorant refers to a chemical agent or formulation rendering the composition with a desired color or other desired visual effect. The pigment may be, for example, a chromophore, a salt, a metal oxide, an encapsulated pigment powder, a thermochromic pigment, a fluorescent pigment, an inorganic pigment, an organic pigment, etc. The term also encompasses metallic particles, magnetic particles, conductive pigments, glass or ceramic particles (frit), luminescent pigments, etc.

[0052] The pigment can be used for mere esthetic effect, or can have a functional meaning (e.g. color code) to indicate one or more properties of the construction element, such as thickness, degree of sound insulation, degree of thermal insulation, etc.

[0053] As noted, the compositions of this disclosure are designed for the manufacture of construction elements therefrom. Thus, according to another aspect, there is provided a construction element comprising: at least 75 wt% of a mixture of plaster particles and concrete particles, and at least 20 wt% of at least one polymer selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof, the particles of the mixture being at least partially embedded in said at least one polymer.

[0054] Typically, the construction element is produced from the compositions described herein according to process to be described hereinbelow.

[0055] According to some embodiments, the construction element comprises between about 35 wt% and about 70 wt% of said plaster particles, between about 5 wt% and about 40 wt% of said concrete particles, and between about 20 wt% and about 25 wt% of said at least one polymer.

[0056] By some embodiments, the construction element is selected from a drywall, a partition wall, a cladding panel, a cladding tile, an acoustic panel, a thermal insulating panel, a block, a brick, a ceiling board, and similar construction elements.

[0057] As noted, while the construction element is typically planar, it is contemplated that the construction element can also be angled or curved panels, or panels having curved sections. The construction element can have a substantially flat, homogenous surface, or can have surface features rendering it with a desired aesthetic effect, such as patterns, grooves, dimples, bulges and the like, randomly distributed over the surface or arranged in various arrays. The surface of the construction element can be texturized to mimic a natural product, such as wood grain or stone effect, or to mimic a synthetic product such as concrete blocks, clay bricks, etc.

[0058] The construction element can be substantially continuous, or can include one or more holes or recesses, e.g. for enabling installation of electrical sockets, communication sockets, windows, connection to water infrastructure, connection to gas delivery infrastructure, or any other infrastructure element.

[0059] According to some embodiments, the construction element has a bottom portion and / or a top portion configured for insertion into a suitable installation rail. For example, a bottom potion and / or a top portion of the construction element may have a different thickness than the majority of the construction element, or may have one or more geometrical features that correspond to suitable complementary features of the rail.

[0060] The construction element may have one or more visual indications to indicate a one or more properties of the element (e.g. color coding, lettering, indicia, etc.), such as thickness, acoustic insulation, thermal insulation, etc. Such visual indication can also be used to provide indication on the proper installation directionality of the construction element.

[0061] According to some embodiments, the construction element has an areal density of between about 0.85 g / cm2and about 1.2 g / cm2.

[0062] By some embodiments, the construction element has a noise reduction coefficient (NRC) rating of at least 0.7.

[0063] By some embodiments, the construction element has a thermal insulation index (U-value) of at least 0.18 W / m2k. By some embodiments, the construction element has a water absorbance rate of no more than about 5 wt% / 2 hours.

[0064] By another aspect there is provided a drywall that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles, and between about 20 wt% and about 25 wt% of at least one polymer selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

[0065] By another aspect there is provided a drywall that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles having an average particle size of at most 500pm, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles having an average particle size of at most 500pm, and between about 20 wt% and about 25 wt% of at least one polymer selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

[0066] By another aspect there is provided a partition wall that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles, and between about 20 wt% and about 25 wt% of at least one polymer selected from selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

[0067] By another aspect there is provided a partition wall that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles having an average particle size of at most 500pm, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles having an average particle size of at most 500pm, and between about 20 wt% and about 25 wt% of at least one polymer selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

[0068] By another aspect there is provided an acoustic or thermal insulating panel that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles, and between about 20 wt% and about 25 wt% of at least one polymer selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

[0069] By another aspect there is provided an acoustic or thermal insulating panel that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles having an average particle size of at most 500pm, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles having an average particle size of at most 500pm, and between about 20 wt% and about 25 wt% of at least one polymer selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

[0070] By another aspect there is provided a drywall that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles, and between about 20 wt% and about 25 wt% of vinyl acetate acrylic copolymer.

[0071] By another aspect there is provided a drywall that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles having an average particle size of at most 500pm, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles having an average particle size of at most 500pm, and between about 20 wt% and about 25 wt% of vinyl acetate acrylic copolymer.

[0072] By another aspect there is provided a partition wall that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles, and between about 20 wt% and about 25 wt% of vinyl acetate acrylic copolymer.

[0073] By another aspect there is provided a partition wall that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles having an average particle size of at most 500pm, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles having an average particle size of at most 500pm, and between about 20 wt% and about 25 wt% of vinyl acetate acrylic copolymer.

[0074] By another aspect there is provided an acoustic or thermal insulating panel that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles, and between about 20 wt% and about 25 wt% of vinyl acetate acrylic copolymer.

[0075] By another aspect there is provided an acoustic or thermal insulating panel that comprising about 35 wt% and about 70 wt% of recycles or reclaimed plaster particles having an average particle size of at most 500pm, between about 5 wt% and about 40 wt% of said recycles or reclaimed concrete particles having an average particle size of at most 500pm, and between about 20 wt% and about 25 wt% of vinyl acetate acrylic copolymer.

[0076] Further provided, by another aspect, is a process of manufacturing a construction element as disclosed herein from a composition as disclosed herein. The process comprising:

[0077] (a) filling a mold of said construction element with said composition;

[0078] (b) drying said composition to reduce the water content of the composition to at most about 10 wt%; and

[0079] (c) removing said mold to obtain said construction element.

[0080] Provided by yet another aspect, is a process of manufacturing a construction element in the form of panel as disclosed herein from a composition as disclosed herein, the process comprising:

[0081] (A) depositing said composition over a receiving surface;

[0082] (B) drying said composition to reduce the water content of the composition to at most about 10 wt%; and

[0083] (C) removing said mold to obtain said panel.

[0084] By some embodiments, the drying is carried out at a temperature ranging between about 100 °C and about 180 °C, e.g. between about 100°C and about 150°C.

[0085] Depending on the amount of polymer emulsion, the composition can have different consistencies. When the consistency of the composition is pourable, filling can be carried out by casting the composition into the mold. When the consistency of the composition resembles a wet-sand consistency, the filling can be carried out by compacting the composition into the mold.

[0086] Filling can be gravitational or can be pressurized, utilizing a suitable pumping system known per-se. In some embodiments, the process further comprises a step (0), prior to step (a), step (0) comprises mixing the particles of plaster and concrete with the water-based polymeric emulsion to obtain said composition.

[0087] In other embodiments, the process further comprises a step (O’), prior to step (a), step (O’) comprises mixing the particles of plaster and concrete with a mixture of said polymer and said surfactant, and water, to obtain said composition.

[0088] Mixing can be carried out for a period of time that ranges between about 5 minutes and about 120 minutes, typically between about 10 minutes and about 60 minutes, at a typical temperature ranging between about 10°C and about 40°C (for example between about 15°C and about 35°C). The composition can be mixed at a mixing speed of between about 70 RMP and 300 RMP.

[0089] By some embodiments, the process further comprises a step (I), prior to step (0) or step (O’), of reducing sorted concrete and plaster waste into a desired particle side. Size reduction can be carried out by any suitable process, e.g. grinding, crushing, pulverizing, etc.

[0090] Processes of this disclosure can be carried out in batches, semi-batch wise, or continuously.

[0091] By another aspect, there is provided a system for constructing a wall, the system comprising: at least one bottom rail comprising a first longitudinal raised border and a second longitudinal raised border, parallel to said first longitudinal raised border and laterally spaced-apart therefrom; at least one at least one top rail, comprising first and second corresponding longitudinal raised borders that correspond to the first and second longitudinal raised borders of the bottom rail; at least a pair of construction elements, said pair of construction elements being a first panel and a second panel, each of said first and second panels having at least a bottom portion thereof configured to be insertable into either the first or the second longitudinal raised borders and having at least a top portion thereof configured to be insertable into either the first or the second corresponding longitudinal raised borders.

[0092] By some embodiments, the first and second panels are construction elements as disclosed herein. In some embodiments, the first longitudinal raised border and the second longitudinal raised border are each configured to receive said bottom portion of the panels, and the first corresponding longitudinal raised border and the second corresponding longitudinal raised border are each configured to receive said top portion of the panels, such that when the first panel is inserted into the first longitudinal raised border and the second panel is inserted into the second longitudinal raised border, a space is defined between the panels.

[0093] The space functions to increase the acoustic and / or thermal insulation properties of the wall. For further acoustic and / or thermal insulation, one or more acoustic or thermal insulating materials can be packed into the space formed between the panels.

[0094] By some embodiments, the system further comprising at least two edge profiles, each configured for fitting over both a side edge of the first panel and a side edge of the second panel.

[0095] By some embodiments, the system comprises two or more pairs of said panels. In such configurations, the system can further comprise at least one vertical beam, having a bottom segment configured for insertion between said first and second longitudinal raised borders and normal to the bottom rail, and between said first and second corresponding longitudinal raised borders and normal to said top rail, said at least one vertical beam having a plurality of longitudinal slits; and at least one complementary profile, having a plurality of hooks, corresponding and in register with said plurality of longitudinal slits. Each longitudinal slit in said plurality of slits is configured to receive and interlock with a hook in said plurality of hooks when the complementary profile is brought into engagement with said vertical beam, such that when one pair of said panels is arranged side-by-side in one or the first or second longitudinal raised borders, adjacent side edges of the panels are clamped between the vertical beam and the complementary profile.

[0096] In other words, the two or more pairs of panels can be arranged to form side-by- side arrangements of the panels in each of the first and second raised borders, such that the length of the wall is a multiplication of the number of panels arranged side-by-side. The engagement between the vertical beam and the complementary profile clamps adjacent side edges of adjacent panels, thereby holding the panels in position.

[0097] The complementary profile can also function to aesthetically obscure the seamlines between adjacent side-by-side panels. According to some embodiments, the complementary profile can be made of a flexible material, e.g. elastic / viscoelastic polymeric material, silicon polymer, malleable metal (e.g. thin aluminum sheet), etc. Such flexibility permits ease of installation of the complementary profile in place.

[0098] By some embodiments, the vertical beam and / or the edge profile are rigid, for example made of metal or rigid plastic, thereby also providing mechanical support to the panels at their line of abutment.

[0099] By another aspect, the present disclosure provides a method of constructing a wall from the system described herein, the method comprising:

[0100] (i) fixing said bottom rail to a bottom surface;

[0101] (ii) fixing said top rail to a top surface;

[0102] (iii) sliding the bottom portion of the first panel into said first longitudinal raised border and the top portion of said first panel into the first corresponding longitudinal raised border; and

[0103] (iv) sliding the bottom portion of the second panel into said second longitudinal raised border and the top portion of said second panel into the second corresponding longitudinal raised border.

[0104] According to some embodiments, step (iii) comprises sliding at least two first panels, side-by-side, into said first longitudinal raised border and said first corresponding longitudinal raised border, and step (iv) comprises sliding at least two second panels, side- by-side, into said second longitudinal raised border and said second corresponding longitudinal raised border.

[0105] By some embodiments, the method further comprises, between steps (i) and (ii), installing, normal to the bottom rail and the top rail, at least one vertical beam between said first and second longitudinal raised borders and normal to the bottom rail.

[0106] In such embodiments, step (iii) can comprise engaging at least one complementary profile with said at least one vertical beam, such that side edges of two adjacent first panels are clamped between the vertical beam and the complementary profile; and step (iv) can comprise engaging an additional complementary profile with said at least one vertical beam, such that side edges of two adjacent second panels are clamped between the vertical beam and the additional complementary profile. By another aspect, there is provided a method of constructing a partition from the system described herein, the method comprising:

[0107] (i) fixing said bottom rail to a bottom surface;

[0108] (ii) sliding the bottom portion of the first panel into said first longitudinal raised border and;

[0109] (iii) sliding the bottom portion of the second panel into said second longitudinal raised border; and

[0110] (iv) fixing said top rail over the first and second panels, such that the top portion of said first panel is inserted into the first corresponding longitudinal raised border and the top portion of said second panel is inserted into the second corresponding longitudinal raised border.

[0111] As used herein, the singular form a, an and the include plural references unless the context clearly dictates otherwise.

[0112] 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.

[0113] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. In the phrases ranging / ranges between (or between about a value and about a value) a first indicate number and a second indicate number and "ranging / ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween. It should be noted that where various embodiments are described by using a given range, the range is given as such merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range.

[0114] Throughout this specification and the claims which follow, unless the context requires otherwise, the word comprise, and variations such as comprises and comprising, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any integer or step or group of integers and steps. Generally it is noted that the term ...at least one... as applied to any component of a composition, constructional element or system of the disclosure should be read to encompass one, two, three, four, or more different occurrences of said component in a composition, constructional element or system of the disclosure.

[0115] It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the disclosure. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0116] Processes of the present disclosure involve numerous process steps which may or may not be associated with other common physical-chemical processes so as to achieve the desired result. Unless otherwise indicated, such process steps, if present, may be set in different sequences without affecting the workability of the process and its efficacy in achieving the desired end result.

[0117] BRIEF DESCRIPTION OF THE DRAWINGS

[0118] 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:

[0119] Figs. 1A-1B show, respectively, the flexural stress at maximal load and flexural module, respectively, at different waste to emulsion ratio, compared to standard, gypsumbased dry walls.

[0120] Figs. 2A-2B show, respectively, the flexural stress at maximal load and flexural module, respectively, of panels having different weight ratios of concrete particles to plaster particles.

[0121] Fig. 3 shows the compression stress at maximal load and flexural module, respectively, of panels made from compositions of the present disclosure, compared to standard, gypsum-based dry walls. Fig- 4 shows the water absorption of panels made from compositions of the present disclosure, compared to standard, gypsum-based dry walls.

[0122] Fig- 5 shows a wall constructed out of a system according to an embodiment described herein.

[0123] Figs. 6A-6B are, respectively, perspective view and cross-sectional view along line II-II, of a bottom rail of the wall of Fig. 5.

[0124] Figs. 7A-7G are consecutive steps for construction of a wall using the system according to an embodiment described herein.

[0125] DETAILED DESCRIPTION OF EMBODIMENTS

[0126] Example 1 preparation of panels

[0127] Preparation of panels from compositions described herein was carried out according to the following process. Construction waste was sorted into components, separating plaster waste and concrete waste from the construction waste. The plaster waste and concrete waste were separately grinded to an average particle size of between about 100 microns and about 300 microns, and then mixed at different weight ratios to form mixtures in particulate form.

[0128] Each of the mixtures was then mixed, in a suitable mixer, with between 10 wt% and 30 wt% of a water-based polymeric emulsion, e.g. a vinyl acetate water-based emulsion to obtain compositions of this disclosure.

[0129] The compositions were then cast into panel-shaped molds having a size suitable for wall construction (for example 90cmx260cmx3cm), and dried at about 120 °C until reaching at most 10 wt% moisture. After completion of drying, the panels were extracted from the molds.

[0130] Example 2 preparation of panels

[0131] Additional panels were prepared by using a mixture of dry polymer and at least one surfactant, that rendered the polymer water-dispersible. Construction waste was sorted into components, separating plaster waste and concrete waste from the construction waste. The plaster waste and concrete waste were separately grinded to an average particle size of between about 100 microns and about 300 microns, and then mixed at different weight ratios to form mixtures in particulate form. Each of the mixtures was then mixed, in a suitable mixer, with between 8 wt% and 15 wt% of dry acrylic vinyl acetate copolymer, between about 20 wt% and 30 wt% water, and one or more surfactants, to obtain compositions of this disclosure.

[0132] The compositions were then cast into panel-shaped molds having a size suitable for wall construction (for example 90cmx260cmx3cm), and dried at about 120 °C until reaching at most 10 wt% moisture. After completion of drying, the panels were extracted from the molds.

[0133] Example 3 - mechanical properties

[0134] Bending samples were produced according to the process of Example 1, using appropriate sample molds, as per the compositions of Table 1. The plaster-concrete mixture was grinded to an average particle size of 200 microns, and then mixed with acrylic vinyl-acetate water-based emulsion, the concentration of the polymer in the emulsion was 85 wt%. Flexural properties were measured according to ASTM C473, and compared to several standard, gypsum-based commercial drywalls (Refs. 1-3).

[0135] Table 1: Compositions for mechanical tests

[0136] The flexural stress at maximal load and the flexural modulus are shown in Figs. 1A-1B. As can be seen, compositions of this disclosure demonstrate higher flexural stresses and the flexural moduli compared to standard drywalls. This indicates that structural elements made out of compositions of this disclosure are expected to have higher flexural properties than standard drywalls, making them more resilient to bending forces.

[0137] The effect of the concrete-to-pl aster weight ratio on the mechanical properties of the composition was tested for composition according to Table 2, prepared in the method of Example 1. The plaster-concrete mixture was grinded to an average particle size 200 microns, and then mixed with acrylic vinyl-acetate water-based emulsion, the concentration of the polymer in the emulsion was 45 wt%. Flexural properties were measured according to ASTM C473. Table 2: Compositions for mechanical tests

[0138] The flexural stress at maximal load and the flexural modulus are shown in Figs. 2A-2B. As can be seen, higher flexural stresses and the flexural moduli are obtained at lower concrete-to-plaster ratio, with the highest flexural properties obtained for a concrete-to-pl aster ratio of 60:40.

[0139] Mechanical properties under compression loads was tests for CompB, in comparison with standard drywall reference samples (Refs. 1-3), according to ASTM C473. The compression stress under maximal load is shown in Fig. 3. As can be seen, the CompB has significantly higher compression resiliency due to the presence of concrete in the formulation, as compared to gypsum-based standard drywalls. Hence, structural elements made of compositions of this disclosure are expected to demonstrate not only improved flexural properties, but also significantly higher resilience to compression loads, in comparison to standard drywalls.

[0140] Example 4 - water absorption

[0141] Water absorption of samples of CompB were compared to commercial standard drywall reference samples (Refs. 1-3). The plaster-concrete mixture was grinded to an average particle size of 200 microns, and then mixed with acrylic vinyl-acetate waterbased emulsion, the concentration of the polymer in the emulsion was 85 wt%. Samples having identical dimensions (2cmx3cmx 1.5cm) of each panel were weighed, and then placed in a water bath at a temperature of 21 °C, and weighted down to ensure full submergence. After 2 hours, the samples were taken out of the water bath, patted to remove surface water, and weight again.

[0142] The change in weight of the samples is shown in Fig. 4. As can be clearly seen, the samples of CompB showed significantly less water absorbance compared to standard commercial dry wall samples (Refs. 1-3). Thus, walls made of composition of this disclosure are expected to provide increased environmental stability, with significant reduction in humidity absorbance, making these suitable for use in various environments.

[0143] Example 5 - exemplary system for wall construction

[0144] Turning to Fig. 5, shown is an exemplary wall constructed by a system according to an embodiment of this disclosure - for example using panels made of compositions described herein.

[0145] Wall 100 is constructed out of a plurality of panels 200, fixed between bottom rail 102 and top rail 104, as will be explained further below. Seen in isolation in Figs. 6A-6B, is bottom rail 102. Rail 102 has a rail base 106, that can be attached to a bottom surface, e.g. a floor, by means of adhering or bolting. A rail space 108 is defined between two, upwardly extending, rail side walls 110 and 112, that terminate, respectively, with a first raised border 114 and a second raised border 116. Raised borders 114b and 116b are dimensioned to receive bottom portions of panels 200, as will now be explained.

[0146] The top rail 104 has a similar configuration, and has raised borders 114t and 116t and dimensioned to receive top portions of panels 200.

[0147] Construction of the exemplary wall 100 utilizing a system as described herein is shown, in sequence, in Figs. 7A-7G. Bottom rail 102 is fixed to a bottom surface, such as a floor of a room in which the wall is to be constructed. A beam -fixating element 118 is then inserted into space 108, as seen in Fig. 7B, and fixed to the rail base 106 by, e.g. a bolt, through opening 120, in a desired location for installation of a vertical beam.

[0148] As shown in Fig. 7C, vertical beams 124 are placed over beam-fixating elements 118, such that the bottom portion of each beam is received within space 108 and held between walls 110 and 112. Ridges 122 defined on the outer surface of beam-fixating elements 118 can be utilized to adjust the relative vertical position between the bottom of the beam and the base surface of the rail, and provides a vertical degree of freedom in installation to accommodate slight variability in the required height of the wall.

[0149] The top rail 104, preferably with corresponding beam-fixating elements 118 installed therein, is fixed over the vertical beams and connected to a top surface, e.g. ceiling.

[0150] First panels 200i, which are preferably panels produced from compositions of this disclosure, are then slid in the direction of arrows 130,132, such that the bottom portion of each of the first panels 200i is received in first longitudinal raised border 114b, and the top portion thereof received in the first corresponding longitudinal raised border 114t.

[0151] Similarly, second panels 20(h, which are preferably panels produced from compositions of this disclosure, are then slid into location, such that the bottom portion of each of the second panels 2OO2 is received in second longitudinal raised border 116b, and the top portion thereof received in the second corresponding longitudinal raised border 116t. As seen in Fig. 7G, such a configuration results in spaced apart first and second panels, defining between them a space S. Space S provides for acoustic and / or thermal insulation, and can optionally further be packed with acoustic and / or thermal insulating material. Space S can also serve to accommodate various infrastructure elements, such as water tubes, electric wires, communication wires, etc.

[0152] In order to hold the panels fixedly in location, as well as to obscure any space formed between two adjacent first panels (or two adjacent second panels) that are arranged side-by-side, a complementary profile 134 is engaged with vertical beam 124 by inserting the complementary profile into a space 128 formed between two adjacent panels (Fig. 7F). Complementary profile 134 is configured with a plurality of hooks 136, that are designed to engage and interlock slits 126 formed in the vertical beam 124. Such an arrangement results in clamping of adjacent side edges of the panels between the vertical beam 124 and the complementary profile 134, thereby fixedly holding the panels in location.

[0153] In order to facilitate easy installation of complementary profile 134 into space 128, the complementary profile 134 can be made of a flexible material, e.g. flexible plastic, silicon polymer, etc.

[0154] Edge profiles 138 can be installed over both a side edge of the first panel and a side edge of the second panel for aesthetic purposes or for providing further rigidity to wall 100.

[0155] The panels 200 can be formed with various openings or recesses to accommodate various infrastructure elements, such as communication sockets, electrical sockets, etc.

[0156] A partition (not shown) that does not extend the full distance between floor and ceiling, can be similarly constructed, e.g. from a pair of first and second panels or from two or more such pairs. In such construction, the top rail is not affixed to a top surface.

Claims

CLAIMS:

1. A composition for manufacturing of a construction element, the composition comprising: at least 65 wt% of a mixture of plaster particles and concrete particles, at least 8 wt% of at least one polymer, and between about 15 wt% and 30% wt% water.

2. The composition of claim 1, wherein said polymer and water are provided in the form of a water-based polymeric emulsion.

3. The composition of claim 1, wherein the polymer is at least one polymer selected from selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof.

4. The composition of claim 3, wherein the polymer is a vinyl acetate acrylic copolymer.

5. The composition of any one of claims 2 to 4, wherein the water-based polymeric emulsion comprises at least 40 wt% of said at least one polymer.

6. The composition of any one of claims 2 to 5, wherein the water-based polymeric emulsion comprises at least 70 wt% of said at least one polymer.

7. The composition of any one of claims 2 to 6, wherein the composition comprises between about 10 wt% and about 25 wt% of said water-based polymeric emulsion.

8. The composition of any one of claims 1 to 7, further comprising at least one surfactant.

9. The composition of any one of claims 1 to 8, wherein the composition comprises between about 8 wt% and about 15 wt% of said polymer.

10. The composition of any one of claims 1 to 9, wherein said mixture has an average particle size of no more than 500 microns.

11. The composition of any one of claims 1 to 10, wherein said mixture has an average particle size of between about 100 microns and about 300 microns.

12. The composition of any one of claims 1 to 11, wherein said plaster particles are particles of plaster of Paris.

13. The composition of any one of claims 1 to 12, wherein said plaster particles are recycled plaster particles.

14. The composition of any one of claims 1 to 13, wherein said concrete particles are recycled concrete particles.

15. The composition of any one of claims 1 to 14, wherein the weight ratio between the plaster particles and the concrete particles in the mixture is between about 1 : 1 and about 1 : 10.

16. The composition of any one of claims 1 to 15, wherein the composition comprises between about 70 wt% and about 85 wt% of said mixture.

17. The composition of any one of claims 1 to 16, wherein the composition further comprises at least one additive selected from flame retarding agents, blowing agents, foaming agents, and colorants.

18. The composition of any one of claims 1 to 17, wherein the composition further comprises one or more reinforcing fibrous materials.

19. A construction element comprising: at least 75 wt% of a mixture of plaster particles and concrete particles, and at least 20 wt% of at least one polymer selected from vinyl acetate acrylic copolymers, acrylic copolymers, vinyl alcohol polymers, vinyl acetate copolymers, vinyl alcohol - vinyl acetate copolymers, polyurethanes, and mixtures thereof, the particles of the mixture being at least partially embedded in said at least one polymer, and the construction element having an areal density of between about 0.85 g / cm2and about 1.2 g / cm2.

20. The construction element of claim 19, comprising: between about 35 wt% and about 70 wt% of said plaster particles; between about 5 wt% and about 40 wt% of said concrete particles; and between about 20 wt% and about 25 wt% of said at least one polymer.

21. The construction element of claim 19 or 20, wherein the weight ratio between the plaster particles and the concrete particles is between about 1 : 1 and about 1 : 10.

22. The construction element of any one of claims 19 to 21, wherein said mixture has an average particle size of no more than 500 microns.

23. The construction element of any one of claims 19 to 22, said plaster particles are recycled plaster particles.

24. The construction element of any one of claims 19 to 23, wherein said concrete particles are recycled concrete particles.

25. The construction element of any one of claims 19 to 24, further comprising at least one surfactant.

26. The construction element of any one of claims 19 to 25, further comprises at least one flame retarding agent.

27. The construction element of any one of claims 19 to 26, further comprises one or more reinforcing fibrous materials.

28. The construction element of any one of claims 19 to 27, having a noise reduction coefficient (NRC) rating of at least 0.7.

29. The construction element of any one of claims 19 to 28, wherein the construction element is selected from a drywall, a partition wall, a cladding panel, a cladding tile, an acoustic panel, a thermal insulating panel, a block, a brick, and a ceiling board.

30. A process of manufacturing a construction element according to any one of claims 19 to 29 from a composition of any one of claims 1 to 18, the process comprising:(a) filling a mold of said construction element with said composition;(b) drying said composition to reduce the water content of the composition to at most about 10 wt%; and(c) removing said mold to obtain said construction element.

31. A process of manufacturing a construction element in the form of panel according to any one of claims 19 to 29 from a composition of any one of claims 1 to 18, the process comprising:(A) depositing said composition over a receiving surface;(B) drying said composition to reduce the water content of the composition to at most about 10 wt%; and(C) removing said receiving surface to obtain said panel.

32. The process of claim 30 or 31, wherein said drying is carried out at a temperature ranging between about 100°C and about 180°C.

33. The process of claim 30 or 32, wherein said filling is carried out by casting the composition into the mold.

34. The process of claim 30, 31 or 33, wherein said filling is carried out by compacting the composition into the mold.

35. The process of any one of claims 30 to 34, comprising a step (0), prior to step (a), step (0) comprises mixing said mixture of particles with said water-based polymeric emulsion to obtain said composition.

36. The process of any one of claims 30 to 34, comprising a step (O’), prior to step (a), step (O’) comprises mixing the particles of plaster and concrete with a mixture of said polymer and said surfactant, and water, to obtain said composition.

37. A system for constructing a wall, the system comprising: at least one bottom rail comprising a first longitudinal raised border and a second longitudinal raised border, parallel to said first longitudinal raised border and laterally spaced-apart therefrom; at least one at least one top rail, comprising first and second corresponding longitudinal raised borders that correspond to the first and second longitudinal raised borders of the bottom rail; at least a pair of construction elements, said pair of construction elements being a first panel and a second panel, each of said first and second panels having at least a bottom portion thereof configured to be insertable into either the first or the second longitudinal raised borders and having at least a top portion thereof configured to be insertable into either the first or the second corresponding longitudinal raised borders.

38. The system of claim 37, wherein the first and second panels are each a construction element of any one of claims 19 to 29.

39. The system of claim 37 or 38, wherein the first longitudinal raised border and the second longitudinal raised border are each configured to receive said bottom portion of the panels, and the first corresponding longitudinal raised border and the second corresponding longitudinal raised border are each configured to receive said top portion of the panels, such that when the first panel is inserted into the first longitudinal raised border and the second panel is inserted into the second longitudinal raised border, a space is defined between the panels.

40. The system of any one of claims 37 to 39, further comprising at least two edge profiles, each configured for fitting over both a side edge of the first panel and a side edge of the second panel.

41. The system of claim 40, wherein said system comprises two or more pairs of said panels.

42. The system of claim 41, further comprising at least one vertical beam, having a bottom segment configured for insertion between said first and second longitudinal raised borders and normal to the bottom rail,and between said first and second corresponding longitudinal raised borders and normal to said top rail, said at least one vertical beam having a plurality of longitudinal slits; and at least one complementary profile, having a plurality of hooks, corresponding and in register with said plurality of longitudinal slits; each longitudinal slit in said plurality of slits being configured to receive and interlock with a hook in said plurality of hooks when the complementary profile is brought into engagement with said vertical beam, such that when one pair of said panels is arranged side-by-side in one or the first or second longitudinal raised borders, adjacent side edges of the panels are clamped between the vertical beam and the complementary profile.

43. The system of claim 42, wherein said complementary profile is made of a flexible material.

44. A method of constructing a wall from the system of any one of claims 37 to 43, the method comprising:(i) fixing said bottom rail to a bottom surface;(ii) fixing said top rail to a top surface;(iii) sliding the bottom portion of the first panel into said first longitudinal raised border and the top portion of said first panel into the first corresponding longitudinal raised border; and(iv) sliding the bottom portion of the second panel into said second longitudinal raised border and the top portion of said second panel into the second corresponding longitudinal raised border.

45. The method of claim 44, wherein step (iii) comprises sliding at least two first panels, side-by-side, into said first longitudinal raised border and said first corresponding longitudinal raised border, and step (iv) comprises sliding at least two second panels, side- by-side, into said second longitudinal raised border and said second corresponding longitudinal raised border.

46. The method of claim 45, further comprising, between steps (i) and (ii), installing, normal to the bottom rail and the top rail, at least one vertical beam between said first and second longitudinal raised borders and normal to the bottom rail.

47. The method of claim 43, whereinstep (iii) comprises engaging at least one complementary profile with said at least one vertical beam, such that side edges of two adjacent first panels are clamped between the vertical beam and the complementary profile; and step (iv) comprises engaging an additional complementary profile with said at least one vertical beam, such that side edges of two adjacent second panels are clamped between the vertical beam and the additional complementary profile.

48. A method of constructing a partition from the system of any one of claims 37 to 43, the method comprising:(i) fixing said bottom rail to a bottom surface;(ii) sliding the bottom portion of the first panel into said first longitudinal raised border and;(iii) sliding the bottom portion of the second panel into said second longitudinal raised border; and(iv) fixing said top rail over the first and second panels, such that the top portion of said first panel is inserted into the first corresponding longitudinal raised border and the top portion of said second panel is inserted into the second corresponding longitudinal raised border.

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