ES2732159B2 - PLASTER LIGHTENED WITH RUBBER POWDER FROM OUT-OF-USE TIRES (NFU) AND REINFORCED WITH CARBON FIBERS, THEIR PROCEDURE FOR OBTAINING AND USE - Google Patents

Description

DESCRIPTION

LIGHTENED PLASTER WITH RUBBER POWDER FROM TIRES

OUT OF USE (NFU) AND REINFORCED WITH CARBON FIBERS, ITS

PROCEDURE FOR OBTAINING AND ITS USE

TECHNICAL SECTOR

The present invention is cataloged within the scope of New Construction Materials and has two main objectives. First, it is possible to immobilize and encapsulate within a gypsum matrix a residue that is difficult to eliminate, which is classified by the European Union as "toxic and dangerous waste" in the European Waste List (LER), with code 16.01. 03. Secondly, a new construction material is obtained with improvements in density, toughness and thermal insulation, maintaining or improving its mechanical resistance thanks to the incorporation of carbon fibers during its execution.

BACKGROUND OF THE INVENTION

Among the residues that are difficult to remove and with an increasing volume over time, are out-of-use tires (NFU), which due to their high calorific value, difficult compaction and ease, due to their way to accumulate gases and leachates, do not its deposit in landfill is recommended. If we add that they are not degradable and are resistant to ozone, light and bacteria, it is understood that it is a waste classified by the EU as toxic and dangerous waste within the European Waste List (LER) with the code: 16.01.03 .

On the other hand, in the thermal conditioning of buildings it is necessary to resort to the use of insulating materials that prevent the transmission of cold or heat from the outside. Taking into account the need to increase the possible applications of recycled materials and to create new materials with properties that improve habitability, a construction material is proposed that combines both aspects.

In this patent application, a new material is developed that, maintaining its mechanical properties within the margins established by current regulations, constitutes an innovative solution in the field of improving thermal conditioning through the use of powdered NFU rubber waste, taking advantage of its elastic properties, low density and chemical stability. Likewise, a decrease in the density of the material is achieved that is directly proportional to the increase in the proportion of NFU rubber, with the consequent lightening of the material.

The incorporation of this residue causes losses of mechanical resistance, being those of compression proportionally higher. For this reason, carbon fibers have been incorporated that produce an outstanding increase in these resistances. Similarly, the resulting material presents a substantial improvement in its toughness.

Below is a list of existing patents on the market related to construction materials with gypsum matrix. In none of the consulted cases an invention similar to the one proposed is claimed.

Invention patent ES2385587 B1 of June 13, 2013, entitled "Lightweight gypsum and coconut panel, and manufacturing procedure", describes a panel designed for use in construction, especially for use in making interior partitioning and Exterior partitioning. The panel is made from a compound consisting basically of gypsum or commercial plaster such as semi-hydrated calcium sulfate and coconut fibers and shell, together with additives such as setting retardant and waterproofing. A process for the preparation of panels that include adding to the gypsum or commercial plaster the necessary additives such as water repellent and setting retardant, adding water until obtaining a workable mass, adding the coconut material, kneading the mixture until the compound is homogeneous, pouring said compound into the frame that acts as a mold, apply vibrated to the whole until a homogeneous distribution, let dry and Extract the panel from the mold.

In the invention patent ES2381726B1 of March 12, 2013, entitled "Procedure for obtaining lightweight gypsum with foamed polyurethane waste", a new lightweight gypsum material is obtained for use in construction, in which industrial waste is incorporated of rigid polyurethane foams The foamed polymeric residues are mixed after grinding with the plaster at different granulometries depending on their use.

Patent ES2277776 B1 of June 16, 2008, entitled "Lightweight gypsum or plaster mixes with expanded plastic granules," establishes lightweight gypsum or plaster mixes with expanded plastic granules. Two ideal gypsum or plaster mixes are mentioned. kneaded with water and added with spherical granules of expanded plastic about 6 mm in diameter, they give construction products. One of the mixtures uses quick-setting gypsum or E-35 plaster that is kneaded for 1 minute with water in a 80% by weight of the dry binder, and the expanded plastic granules are added in a proportion of 1.6% by weight of dry binder, continuing to knead for 3 or 4 minutes. For the preparation of the second mixture, it uses plaster E-35 mixed with water at 200% in relation to the dry weight of the binder for 2 minutes, to which is added 8.1% of foamed plastic by weight of the binder and they are kneaded last you 5 minutes.

Similarly, the invention patent ES2292309B2 of February 16, 2009, entitled "Gypsum or plaster construction material and its use in plates and panels", develops a lightweight plaster or plaster construction material and its use in plates The invention consists of a material with which a very light plaster or plaster is obtained for the manufacture of large format prefabricated plates and panels for use in construction, which allows a considerable reduction in weight so as to enable a Ease of handling while reducing the anchoring systems necessary for placement on site.This material is made of any type of plaster or plaster as the main matrix, with binary additions of expanded polystyrene and polypropylene fibers that allows reducing weight in fifty percent maintaining the values of mechanical resistance, porosity, hardness and setting times.

Another of the patents with previous examination analyzed is ES2170612 B2 of September 16, 2003, entitled "Lightweight gypsum with cork and its application in panels for construction", which claims lightweight gypsum with cork and its application in panels for construction. Creating a material based on gypsum or plaster lightened with natural cork that are pruning waste in the form of granules or with artificial cork and, in particular, expanded polystyrene beads of medium grain size, suitable for use in the form of panels in prefabricated construction products, especially panels for partitions and linings The invention has the advantage of reducing panel weight by up to 50% less than plaster panels alone and the cost thereof, maintaining resistance, improving thermal and acoustic insulation, and facilitating its transport To improve the workability, reinforce and reduce the water / plaster ratio, glass fibers, superfluidifiers and setting retarders are added.

The utility model ES1050538 U of April 16, 2002, entitled "Improved structure for plasterboard partitions", includes among its claims the development of an improved structure for plasterboard partitions, designed with the aim of achieving greater acoustic insulation. Between the plates there is a metal profile of "U" channels for the floor and ceiling, as well as a series of equidistant posts, to which the two panels on both sides of the partition are screwed, the base channel of the profile having an elastic expansion joint, characterized in that it includes acoustic bands arranged on the external faces of the metal profiles, both in the floor and ceiling channels and in the uprights, being interposed in the coupling of the plasterboard panels, acting as bands dampers to reduce the resonance frequencies of the galvanized steel profiles that compose it. In his claim 3, the use of rubber pellets in said acoustic bands is mentioned.

Utility model ES1024914 U of October 16, 1993, entitled "Elastic base for profiles and plates of cardboard, plaster or similar materials", mentions the use of solid rubber in plasterboard, with a staggered configuration, having one or more steps, existing on the central step or step a metallic covering formed by a plate with dimensions similar to the covered area and a circular central hole that communicates to the body of the base in which a recess or recess is located, which it adopts the shape of an inverted cone trunk or the like, which has a circular perforation at its base, through which a screw is attached to the ground, which can be replaced for fixing to the ground by an adhesive film.

The utility model ES1025259 U of December 1, 1993, entitled "Improved damping device, applicable for the elastic attachment to walls of the reinforcement profiles for plasterboard plates or the like", explains the invention of an improved damping device , applicable for the elastic fixing to the walls of the reinforcement profiles for plasterboard or similar, of those intended to be used in insulation installations in general, characterized by being made from a metal plate, which can have any configuration on the ground and that has one or more holes through which conventional screws or rivets pass to fix it to the facing, the plate having a solid rubber or rubber fixed on its exposed surface, which can optionally be placed on its face view of a metal part with a central perforation.

Patent ES2531461 B2 of August 11, 2015, entitled "Procedure for obtaining lightened gypsum plasterboard with polyamide powder residue", shows the development of a laminated gypsum board designed for use in construction, especially for its employment in the realization of interior and exterior partitioning. Said plate is made from a compound consisting basically of gypsum or commercial plaster such as semi-hydrated calcium sulfate and polyamide powder residues, with the possible incorporation of additives and fibers. The plate preparation procedure involves adding polyamide residues to the dry plaster or plaster, adding water until a workable mass is obtained, kneading the mixture until the compound is homogeneous, pouring said compound into the mold-acting frame, allowing it to dry and remove the plate from the mold. The procedure develops the obtaining of the product and its use based on the different properties of the material from different dosages, improving some of the basic properties such as workability, finish and thermal insulation.

Invention patent ES2522792 B1 of June 3, 2015, entitled "Procedure for obtaining lightened gypsum plasterboard with residue of polyurethane foam, plate obtained and use thereof", describes obtaining lightened gypsum plasterboard with polyurethane foam residue, plate obtained and use thereof. The procedure for obtaining a laminated gypsum board designed for use in construction, especially for use in making interior partitioning, is shown. Said plate is made from a compound consisting basically of gypsum or commercial plaster such as semi-hydrated calcium sulfate and crushed polyurethane foam residues, with the possible incorporation of additives and fibers. The plate preparation procedure involves adding polyurethane residues to the dry plaster or plaster, adding water until a workable mass is obtained, kneading the mixture until the compound is homogeneous, pouring said compound into the mold-acting frame, allowing to dry and remove the plate from the mold.

In the invention patent ES2396096 B2 of September 2, 2013, entitled "Procedure for obtaining light gypsum with polyamide powder residue", a construction plaster manufactured from calcium sulfate dihydrate with different substitutions of gypsum for polyamide is developed recycled powder. This invention is based on obtaining a lightweight material obtained from the recycling of polyamide powder, which replaces lightweight plasters, eliminating all or part of the expansive aggregates or other more traditional compounds that are used in the manufacture of these products. The invention protects, in addition to the product, its obtaining procedure and its use based on the different properties of the material from different dosages, improving some of the basic properties such as workability, permeability and insulating capacity due to the inclusion of air.

The European patent ES2104622 T3 of October 16, 1997, entitled "Gypsum board reinforced with fiberglass and procedure for its manufacture", is characterized by claiming a gypsum board reinforced with fiberglass, with a gypsum matrix of high density containing fiberglass stacked as a frame and together with it forms a pressure-resistant solid body skeleton, in which a multitude of very small hollow spaces are embedded, with a diameter between 5 and 350 (mu) m and are created by a fluffy structure of fine pores or at least partially small particles of non-porous and non-absorbent filler ingredient.In the manufacturing process of such fiberglass reinforced gypsum board, gypsum is added and the fiberglass parts with not much water, so that the weight ratio of water / plaster does not exceed 0.6, whereby sponge and / or d filler material is added It is in such an amount that the bulk density of the total table is at least 20% lower than the density of the matrix binder components and the paste is subjected to high frequency vibration for its formation.

Finally, in patent application ES0439064 A1 of June 16, 1977, entitled "A method for the manufacture of reinforced gypsum laminates", a method for the manufacture of reinforced gypsum laminates is established, characterized by proceeding with impregnation of a glass and carbon fiber reinforcing fabric by means of a gypsum grout, prepared using gypsum previously autoclaved, against a molding surface and heating the impregnated reinforcement in this way to produce its drying, achieving a reinforced laminate with lower thickness to five millimeters.

Consequently, there is currently no material that meets the conditions of the present invention or is included among its powers.

Therefore, the object of the present invention is a new plaster lightened with rubber powder from end-of-life tires (NFU) and reinforced with carbon fibers and the procedure for obtaining said lightened plaster different from the materials and their methods. of obtaining described in the state of the art.

DESCRIPTION OF THE INVENTION

Thus, a first object of the invention is a lightened and reinforced plaster for construction characterized in that it comprises a water / plaster ratio of 0.40 to 0.80 and additionally comprises the following components related to the weight of the lightened plaster:

• 5% to 60% by weight rubber powder from end-of-life tires, and

• 0.1% to 5% by weight of carbon fibers; Y

where the sum of all the components is less than or equal to 100%.

In an embodiment of the present invention, the dosage of each component depends on the use that will be given to the material. Based on this, the amount of rubber powder will be increased and that of carbon fiber will be reduced, in the event that there is no high requirement for mechanical properties, but there is a greater requirement for thermal insulation.

Said lightened plaster is characterized because it has the following technical characteristics:

- Its dry bulk density in the hardened state is between 650 Kg / m3 and 1,300 Kg / m3.

- The mechanical resistance to compression varies between 1.2 MPa and 14 MPa 7 days after the gypsum has set.

- The mechanical resistance to flexion is between 1 MPa and 13 MPa 7 days after the plaster has set.

- Thermal conductivity varies between 0.15 and 0.25 W / m * K.

All the technical characteristics of the lightweight gypsum described in this patent document have been measured under laboratory conditions corresponding to a temperature of 23 ± 2 ° C and a relative humidity of 50 ± 5%.

Both in the fresh state and in the hardened state, the lightened plaster object of the invention complies with all the specifications established in the UNE-EN 13279-2: 2014 standard, which is also referred to in this document as "standard "

The lightweight gypsum object of the invention comprises gypsum, rubber powder, carbon fibers, which in the context of the present invention are called the solid components. Based on this, the lightened plaster object of the invention is characterized in that it comprises a water / plaster ratio between 0.40 and 0.80.

In a preferred embodiment of the present invention, the starting plaster comprising the plaster object of the invention complies with the UNE-EN 13279-2: 2014 standard with a mechanical flexural strength greater than 3 N / mm2

Said plaster object of the invention is a lightened and reinforced plaster with substitution of plaster for recycled rubber from end-of-life tires that is added to the composition of the new lightened plaster in powder form.

The rubber dust from end-of-life tires (NFU) comes from the mechanical grinding in an ambient atmosphere of NFU. In the context of the present invention, the physical properties and the chemical analysis, under laboratory conditions as previously indicated in this patent document, are as follows:

TABLE

PROPERTIES

^{Chemical analysis} Minimum (%) Maximum {%)

^{E xtra cto ce t ic ic} 10 20

^{P or limits NR / SR} 40 55

^{C au ch ona your ral NR} 21 42

^{N eg ro de ca rb ono} 30 38

^{C en iza s} 3 7

^{A zu fr e} - 5

Physical Properties

Bulk density 0.5 ± 0.05 gr / cm3

Humidity <0.75% by weight

Material content <0.01% by weight

ferromagnetic

Table 1. Chemical analysis and physical properties of the NFU rubber used in the method object of the invention.

In the context of the present invention, the granulometric analysis of the NFU rubber powder is shown in the following table:

% PASSES THROUGH EACH SIEVE

Nominal al ta rtu ra (mm) Min im o (%) Max im o (%)

0, 800 100 100

0.500 50 80

0, 250 5 30

0.125 0 10

Table 2. Rubber powder 0.0mm-0.6mm. Granulometric analysis.

In a preferred embodiment of the present invention, the plaster object of the invention comprises from 10% to 45% by weight of NFU rubber powder, and in an even more preferred embodiment, the plaster comprises 35% to 45% by weight of powder. NFU rubber.

In the context of the present invention, the characteristics of the carbon fibers used, under laboratory conditions as defined in this patent document, are as follows:

Table 3. Properties of Carbon Fiber.

In a preferred embodiment of the present invention, the gypsum object of the invention comprises from 0.5% to 3.5% by weight of carbon fibers, and in an even more preferred embodiment, the gypsum comprises 0.9% to 2 7% by weight of carbon fibers.

Another object of the invention is a process for obtaining lightened and reinforced gypsum with the replacement of gypsum by NFU rubber powder and carbon obtained from the mixture of water, gypsum, NFU rubber powder and carbon fibers, comprising the following stages:

a) Mix the recycled NFU rubber powder with the gypsum at room temperature between 21 ° C to 25 ° C until the mixture is homogeneous and, in a preferred embodiment, for a time of 50 to 90 seconds;

b) Mix the product obtained with carbon fibers at an ambient temperature of between 21 ° C to 25 ° C, until the fibers completely disintegrate and obtain a homogeneous mixture; Y

c) Add the necessary amount of water complying with a water / plaster ratio of 0.40 to 0.80 and knead in a mixer the mixture obtained in stage b for 50 to 70 seconds at a speed of between 135 to 150 min -1 in rotation, and at a speed of between 50 to 75 min-1in planetary motion.

The kneading procedure is carried out in accordance with the UNE-EN 13279-2: 2014 standard, according to Part 2 of Test Methods.

In a preferred embodiment of the present invention, said process begins with a dry mixing of the gypsum and rubber powder, with the carbon fibers being finally incorporated until a homogeneous dispersion thereof is achieved in a dry kneading container. The assembly is moved with a spoon until the material is as uniform as possible. In a more preferred embodiment, the dry kneading time is 50 to 90 seconds.

In a preferred embodiment of the method object of the invention, the water is added in a ratio with the plaster of 0.40 / 0.80 by means of the shaking table method. The amount of water is weighed on the basis of the water / gypsum ratio indicated above and poured into the dry kneading container into the gypsum-fiber mixture and manually stirred with a trowel for a time between 50 seconds and 90 seconds. In a preferred embodiment of the present invention, it is manually removed for 60 to 75 seconds and, in an even more preferred embodiment, it is removed for 60 seconds.

In a preferred embodiment, the paste formed in the previous stage is mixed with a mixer-kneader for a time of between 50 to 75 seconds at a speed, in a preferred embodiment, of between 135 to 150 min-1 in rotation, and being in an even more preferred embodiment a speed of between 135 to 145 min-1 in rotation and in an embodiment of the present invention, at a speed of between 50 to 75 min-1 in planetary motion, and in an even more preferred embodiment 60 to 75 min "1 in planetary motion.

In particular embodiments, immediately after the described preparation, the gypsum, rubber and carbon fibers paste is passed to previously greased molds of size 4+ 2 cm x 4+ 2 cm x 16+ 4 cm, with the help of a spatula to fill holes and corners.

In preferred embodiments of the method object of the invention, to eliminate the appearance of air bubbles, the mold is raised at a distance between 6 to 12 mm from its upper end on the surface where the mold is resting and is dropped. This operation is repeated between 5 to 8 times. Once the bubble removal stage has been completed, the excess material is removed from the molds with a metal ruler or a knife, using a saw movement.

When the paste has acquired the appropriate degree of consistency as established by the UNE-EN 13279-2: 2014 standard, the plaster object of the invention is removed from the mold.

In a preferred embodiment of the present invention, said plaster obtained in the previous step, is kept for seven days in the laboratory atmosphere indicated in the UNE-EN 13279-2: 2014 standard where the temperature of the test room of the equipment and of the materials, it must be 23 ± 2 ° C and the relative humidity 50 ± 5%.

Then, in a preferred embodiment, the set mixture is dried to constant mass at a temperature of 40 ± 2 ° C. In the context of the present patent application, the constant mass is that mass in which the difference in mass of two successive weighings spaced 24 hours apart, is less than 0.1%, as established by the standard.

It should be noted that the method object of the invention described in this document is carried out under ambient conditions of 23 ± 2 ° C temperature and relative humidity of 50 ± 5%, as previously indicated, and thus the norm establishes it.

For the development of the material, the physical-chemical characterization of rubber powder and carbon fibers has been carried out, and the characterization of light plaster in the fresh state and in the hardened state, in accordance with current European regulations.

For the subsequent mixing, a water / plaster ratio is considered that provides a consistency of the plaster paste per shaking table according to UNE-EN 13279-2: 2014.

Thus, the main advantages derived from the method object of the invention is to obtain a new material, also the object of the invention, with improvements in density, toughness and thermal behavior; holding or improving its mechanical resistance thanks to the incorporation of carbon fibers during its execution, an environmental benefit is also achieved since a residue of difficult elimination is encapsulated within the matrix of new material, which is classified by the European Union as "toxic waste and dangerous ”in the European Waste List (LER), with the code 16.01.03.

At an industrial level, the lightweight gypsum described in this document is a construction material of great value, since by understanding among its essential components the dust from out-of-use tires, the accumulation of this type of material is reduced, in addition of conferring a new value in the construction industry by being part of the matrix of the material object of the invention, ceasing to be a waste which is classified as toxic and dangerous material.

PREFERRED EMBODIMENT OF THE INVENTION

In order to contribute to a better understanding of the invention, and according to a practical embodiment thereof, a preferred embodiment of the present invention is attached as an integral part of this description. Both the preparation of the samples and all the tests carried out were carried out under laboratory conditions corresponding to a temperature of 23 ± 2 ° C and a relative humidity of 50 ± 5%.

The characteristics of the plaster used as a reference in the elaboration of the different examples are as follows:

The required water / plaster ratio according to the standard is 0.60.

The setting principle is: 10 minutes

The wet bulk density: 1628.99 Kg / m3

The dry bulk density: 1203.38 Kg / m3

Shore C hardness: 90.7 Shore C units

Flexural traction: 6.68 MPa

Compression: 17.73 MPa

Thermal conductivity (A): 0.30 W / m * K

Example 1. Manufacturing process

Dosing and mixing of 840 gr of gypsum, 150 gr of NFU rubber powder and 10 gr of carbon fibers is carried out, always in accordance with that specified in the UNE-EN 13279-2: 2014 standard.

Properties of the plaster in the fresh state:

• Water / Plaster ratio: 0.60

• Setting principle: 12 minutes

Properties of gypsum in the hardened state:

Wet bulk density: 1,497.13 Kg / m3

Dry bulk density: 1070.18 Kg / m3

Shore C hardness: 82 units Shore C

Flexural traction: 8.75 MPa

Compression: 9.39 MPa

Thermal conductivity: 0.20 W / m * K

This preferred embodiment of the method begins with a dry mixing of 940 grams of gypsum with 50 grams of rubber powder, with 10 grams of carbon fibers being finally incorporated until a homogeneous dispersion thereof is achieved. The assembly is moved with a spoon until the material is as uniform as possible.

Once 600 gr of water have been measured, the previous mixture is incorporated and manually stirred with a paddle for 60 seconds. Add the plaster to the water and remove it manually with the spatula and trowel for approximately 60 seconds. The formed paste is mixed with the kneading mixer for 60 seconds at low speed 140 ± 5 min-1 in rotation and 62 ± 5 min-1 in planetary motion.

Immediately after preparation, the pasta is transferred to molds. To eliminate the appearance of air bubbles, the mold is raised to a distance between 10 mm from its upper end and dropped. This operation is repeated 5 times. Once this process is completed, the excess material is removed with a metal ruler or a knife, using a saw movement.

When the paste has acquired the appropriate degree of resistance, the specimens are removed from the molds, identified and weighed. The specimens are kept for seven days in the laboratory atmosphere indicated in the standard where the temperature of the test room, the equipment and the materials must be 23 ± 2 ° C and the relative humidity 50 ± 5%.

The specimens are then dried to constant mass at a temperature of 40 ± 2 ° C. After drying, the specimens are cooled in a desiccator to laboratory temperature, weighed and tested.

Claims (8)

1. Lightweight gypsum for construction characterized in that it comprises a water / gypsum ratio of 0.40 to 0.80 and additionally includes the following components related to the weight of lightweight gypsum: i. 5% to 60% by weight of rubber dust from end-of-life tires, and ii. 0.1% to 5% by weight of carbon fibers; Y where the sum of all the components is less than or equal to 100%. 2. Lightened plaster for construction according to claim 1, characterized in that its dry bulk density in the hardened state is between 650 Kg / m3 and 1,300 Kg / m3. 3. Lightweight plaster for construction according to any one of the preceding claims, wherein the compressive mechanical resistance varies between 1.2 MPa and 14 MPa at 7 days of setting. 4. Lightweight plaster for construction according to any one of the preceding claims, where the mechanical resistance to bending is between 1 MPa and 13 MPa at 7 days of setting. 5. Lightweight plaster for construction according to any one of the preceding claims, wherein the thermal conductivity varies between 0.15 and 0.25 W / m ° K. 6. Method for obtaining lightweight gypsum for construction according to any one of the preceding claims, wherein said method is characterized in that it comprises the following steps: to. Mix in a mold the rubber dust of used tires with plaster in a ratio, at a temperature between 21 to 25 ° C until obtaining a homogeneous mixture; b. Add carbon fibers to the mixture obtained in the previous stage at a temperature between 21 to 25 ° C, until the complete disintegration of the carbon fibers and obtaining a homogeneous mixture; c. add water fulfilling a water / gypsum ratio of 0.40 to 0.80 and knead the mixture obtained in stage b in a mixer for 50 to 70 seconds at a speed of between 135 to 150 min-1 in rotation and at a speed of 50 to 75 min-1 in planetary motion. 7. Method for obtaining lightweight gypsum for construction according to claim 6, wherein said method comprises an additional step subsequent to step c) which comprises drying the mixture at a temperature between 38 to 42 ° C. 8. Use of a lightweight plaster for construction according to any one of claims 1 to 5, for the manufacture of lightweight and reinforced precast materials in the form of plates and panels.