WO2013011463A1

WO2013011463A1 - Aggregate mixture for preparing an artificial conglomerate and artificial conglomerate prepared by such mixture

Info

Publication number: WO2013011463A1
Application number: PCT/IB2012/053656
Authority: WO
Inventors: Piermatteo D'AMICO
Original assignee: Progene Llc
Priority date: 2011-07-20
Filing date: 2012-07-18
Publication date: 2013-01-24
Also published as: ITVI20110195A1; EP2744769A1

Abstract

An aggregate mixture for preparing an artificial conglomerate having high thermal conductivity properties including comprising an amount ranging between 0,1 and 2.500 kg/m³ of at least one of the following sands: silica, quartz, carbonate, copper, aluminum or similar, and an amount of rubber aggregate ranging between 10 and 1.200 kg/m³.

Description

AGGREGATE MIXTURE FOR PREPARING AN ARTIFICIAL CONGLOMERATE AND ARTIFICIAL CONGLOMERATE PREPARED BY SUCH MIXTURE

DESCRIPTION

The present invention relates to the field of building materials and, in particular, concerns an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, as well as the artificial conglomerate itself, prepared through such a mixture .

Even more in detail, the present invention refers to a aggregate mixture and a related artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity for arranging prefabricated load-bearing structures, such as, for example, by indicative and not fully exhaustive way, beams or pillars, or for producing slabs or panels for radiating or insulating systems.

Concrete conglomerate reinforced prefabricated slabs currently on the market generally comprise a substrate made of reinforced and vibrated concrete conglomerate, having variable thickness, a reinforcement, embedded and spread into the substrate, consisting of an electro-welded mesh or single reinforcements arranged in a mesh pattern.

The prefabricated slabs of known type also include a variable number of iron frameworks made of electro-welded steel, additional bars made of steel and any lightening elements made of expanded polystyrene.

Alternatively, the prefabricated slabs present a double plate between which the conglomerate jet is carried out, obtaining the same mechanical features of the in situ concrete, and then forming the structural load-bearing elements of civil or industrial buildings.

The very nature of the concrete conglomerate gives it the mechanical properties of very high compressive strength, but low resistance to flexion and traction.

In producing load-bearing structures, this entails the necessary association of a reinforcement, usually made of metal, able to perfectly bind with the concrete, presenting the same factor of thermal expansion.

In this way, the reinforcement, made of a material provided with the necessary elasticity and resistance to tensile and flexion stresses, gives the concrete these mechanical properties .

However, this solution entails the drawback of using quite expensive materials, such as steel.

For these reasons, sizing and checking operations of the reinforcement in a structure, intended to minimize the amount of such material, but at the same time to ensure the stability of the building, are quite complex.

In particular, in buildings subject to seismic forces, it is necessary to greatly increase the elasticity of the structure, especially at its nodes, and consequently the amount of reinforcement, thus raising the cost of the structure, its weight and its vulnerability to corrosion. Another drawback of the concrete conglomerate nowadays widely used for the aforesaid applications is its water permeability, which often causes infiltrations within the structures: such an aspect can be harmful to the structures themselves, since the expansion due to the lowering of temperature causes lesions in the conglomerate, weakening its resistance to stresses.

A solution to this drawback can be given by the use of epoxy resins, currently used also in phase of building recovery and/or restoration of yet existing structures, in particular in order to block the capillary rise of water from the soil. These resins, however, present the drawback of making more rigid the entire building, therefore their use must be limited to localized injections in order to avoid losing the overall elasticity of the building.

A further drawback of the concrete conglomerate derives from the fact of being subject to the phenomenon of carbonation which creates favorable conditions to the striking of corrosion of the reinforcement.

Again, the known cement conglomerate presents the drawback of having a poor capacity to conduct heat, with the consequence that it is certainly suitable to be used as an insulator but unsuitable to be used in radiant prefabricated panels.

It is clear, therefore, the need for an aggregate mixture, and a related artificial conglomerate, which confer to the structure made a traction and flexion strength greater than the prior art, using also a material less expensive than those ones currently used.

Prior art documents ES22217930 Al and BE1008040 A3 disclose purely and necessarily concrete-based artificial conglomerates in which the addition of rubber takes place respectively with the purpose of thermal insulation and lightening and the purpose of acoustic insulation or absorption .

It follows that these artificial conglomerates are suitable for structural applications - such as typically coatings, architectural or urban design elements - which do not require high performances to the constituent materials.

On the other hand, prior art in the form of scientific literature available to the applicant specifically refers to concrete aggregates in which the rubber is added with the purpose of improving the resistance to cracks or breakings due to shrinkage (or narrowing) or acting on the physical- mechanical properties and water absorption of the cement compounds .

The present invention intends to overcome the aforesaid drawbacks of the prior art.

In particular, primary purpose of the invention is to provide an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, and an artificial conglomerate thus prepared, which are resistant to compression, traction and flexion, even in absence of metallic reinforcement.

Another purpose of the present invention is to create an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, and an artificial conglomerate thus prepared, which are waterproof, but, at the same time, sufficiently elastic to ensure the stability of a structure obtained through their use.

Another purpose of the present invention is to indicate an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, and an artificial conglomerate thus prepared, which, contrary to conglomerates of equivalent application, are not subject to the phenomenon of carbonation.

Further purpose of the invention is to devise an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, and an artificial conglomerate thus prepared, which are able to absorb the stresses due to seismic vibrations, guaranteeing the stability of a structure built by means of them. Furthermore, purpose of the present invention is to provide an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, and an artificial conglomerate thus prepared, which are able to transmit heat, in order to be used in the production of fluid heat-carrier and electrical resistance radiant panels, for indoor and outdoor environments since they are impermeable to water and freeze-resistant .

Still a purpose of the invention is to provide an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, and an artificial conglomerate thus prepared, which require the use of little expensive and easily available on the market materials.

A last but not least purpose of the present invention is to develop an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, and an artificial conglomerate thus prepared, which are economically advantageous and easy to be produced.

Said purposes are achieved through an aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity as the appended claim 1, as hereinafter referred for the sake of brevity.

Further technical features of detail of the aggregate mixture of the invention are reported in the related dependent claims .

Integral part of the present invention is also an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, prepared through the aforesaid aggregate mixture, as claim 11, as still hereinafter referred for simplicity of exposition .

Other technical features of the artificial conglomerate of the invention are contained in the corresponding dependent claims .

Object of the present invention is also the use of the aforesaid aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, as the attached claim 21.

Advantageously, the aggregate mixture of the present invention, simple to be manufactures and applicable event to prefabricated panels already in production, allows to provide outdoor radiant panels, which can be used for covering roofs and useful for melting snow during winter and storing heat and subsequently heating hot water in the warmer months.

Basically, therefore, unlike the prior art, the aggregate mixture which is exclusively claimed herein is used for preparing artificial conglomerates having high thermal conductivity properties without providing the necessary use of concrete.

Equally advantageously, the present invention allows to produce prefabricated panels which keep the compression resistance typical of the concrete and, in addition, present a high cohesion and elasticity, so they are modules which can be trod upon and are suitable to carts just after their application, but at the same time they are completely devoid of porosity, thus water-resistant and suitable to house heating/cooling plants, even if they are placed outdoors. The features of mechanical strength and elastic modulus allow the production of modules suitable for both mechanically and climatically renovating the flooring.

In a preferred embodiment, the artificial conglomerate of the invention, not necessarily contemplating the use of hydraulic binders expressly provided, however, in the prior art, presents mechanical features of high deformability and elastic memory such as to bring the deformation/breaking load beyond the limits allowed by the concrete-based artificial conglomerates (provided with hydraulic binders) currently in use .

In particular, the deformability without breaking (i.e., in absence of damage) of the artificial conglomerate of the invention, establishes at values higher of at least 30÷40% than those ones of concrete-based artificial conglomerates of known type.

Another advantage of the present invention is given by the possibility to produce structures with a flame resistance up to a duration of 180 hours.

Moreover, the versatility of the materials used allows to provide panels of different shapes and sizes, able to perfectly reproduce the shape and colour of natural materials, drastically reducing the environmental impact despite the possible high technology used.

Basically, therefore, the invention presented herein allows to create handworks (artificial conglomerates) suitable to be used for a thermo-conductive removable flooring with which conditioning of the inner and outer environments is obtained. Said purposes and advantages, as well as others which will emerge below, will appear more evident from the following description, relating to some illustrative, indicative and preferred, but not limiting embodiment formulas, of the aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity, as well as of the artificial conglomerate prepared through such an artificial mixture, with the aid of the appended figures, in which:

- figure 1 shows a first application of the artificial conglomerate of the invention;

- figure 2 shows a second application of the artificial conglomerate of the invention.

In detail, the aggregate mixture for the preparation of an artificial conglomerate having high thermal conductivity properties, according to the present invention, comprises a quantity variable between 10 and 1,200 kg/m³ of a rubber or rubber-based aggregate.

Such a rubber aggregate is obtained by a known treatment of the exhausted or abandoned tires, used on vehicles, which allows to make them completely odorless and free of the fibres typically contained in them.

Subsequently, the resulting rubber is triturated so as to obtain a granulometry not exceeding 8 mm in diameter.

In particular, an amount ranging between 0.1 and 4,700 kg/m³ of sands of mineral nature is added to this rubber aggregate thus obtained.

Preferably but not necessarily, an amount ranging between 0.1 and 2,500 kg/m³ of these sands of mineral nature is constituted by silica or quartz or carbonate sands.

More precisely, a portion variable between 0.1 and 1,500 kg/m³ of the latter quantity presents a granulometry not exceeding 30 mm in diameter, while a portion variable between 0.1 and 1,000 kg/m³ presents a garnulometry in the range of 1÷6 mm in diameter.

So thin granulometry of the rubber resulting from the treatment of the exhausted tires allows the other materials to mix completely, and to provide a mixture for the preparation of an elastic conglomerate having high thermal conductivity properties, but at the same time uniformly resistant to compression. In a preferred embodiment of the aggregate mixture according to the current invention, an amount ranging from 0.1 to 1,000 kg/m³ of aggregates suitable to transmit heat, for example of metallic nature, such as a corundum, copper, zinc, aluminium, graphite or other metals sand whose use is allowed by the laws in force, having in particular a granulometry not exceeding 6 mm in diameter, is added to the mixture described above .

Such an embodiment presents in this way the advantage of combining the elasticity of a rubber and the compression strength of the inert aggregates to the conductivity of these sands .

In a further preferred embodiment of the invention, an amount ranging between 0.1 and 600 kg/m³ of water-repellent expanded clay, in a granulometry not exceeding 6 mm in diameter, is added to one of the two mixtures described above.

Again, an amount ranging between 0.1 and 600 kg/m³ of pumice stone, in a granulometry not exceeding 20 mm in diameter, and/or an amount ranging between 0.1 and 100 kg/m³ of glass spheres, depending on the aesthetic/mechanical effect which is desired to obtain, can be added to the previous preferred embodiments of the invention.

In a first embodiment of the artificial conglomerate according to the invention, it is provided an embodiment of the aggregate mixture according to the invention, to which an amount ranging from 0.1 to 500 kg/m³ of a natural binder is added .

In particular, such a binder may be constituted by a hydraulic binder, for example white or gray concrete, in an amount ranging up to a maximum of 400 kg/m³, or by an air binder such as, advantageously and surprisingly, anhydrite, material not yet employed at the current state of the art in the building sector in view of the applicative purposes provided by the present invention.

The anhydrite, indeed, is a completely pure mineral which, in the building sector, results the most environmentally friendly and biocompatible one among those existing in nature, even more the hydraulic lime.

In a second embodiment of the artificial conglomerate according to the invention, there is provided a form of aggregate mixture described above, to which an amount ranging from 0.1 to 400 1/m³ of a synthetic binder is added which, advantageously, gives the artificial conglomerate itself deformability and elastic memory properties.

More precisely, such a synthetic binder can be water- catalyzed, in a maximum amount of 250 1/m³, or can be solvent-catalyzed, in any case, according to the regulatory changes in the sector of building polymers.

In both cases, it may be an epoxy, polyurethane, vinyl and/or acrylic or similar resin.

In a third preferred embodiment of the artificial conglomerate according to the present invention, there is provided the mixture of a natural binder with a synthetic binder, such as white concrete and epoxy resin.

In further preferred embodiments, the artificial conglomerate according to the invention presents a metallic reinforcement. For example, the reinforcement can be constituted by a mesh of fibrillated fibres, the module of the mesh having a side variable from 5 to 50 mm in an amount ranging from 0.1 to 1 kg/m³.

Preferably but not exclusively, the fibres may be made of polypropylene, with a side of the mesh module ranging from 5 to 40 mm in lenght.

Alternatively, the fibres may be made of glass, with a side of the module ranging from 5 to 40 mm.

Still in a preferred embodiment, the reinforcement can be constituted by metallic fibres, or by steel rods, whose size is to be calculated on the basis of the expected loads, in compliance with the laws in force.

Doses of the components of three preferred, although not limiting, embodiments of the artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity according to the invention are given below, in table 1.

Table 1

Example 1

As it is deduced from the aforesaid table 1, the following doses are provided in this case:

• 80 L/m³ of water-catalyzed epoxy resin;

• 1000 kg/m³ of rubber aggregate in a granulometry ranging from 0 to 2.8 mm in in diameter;

• 700 kg/m³ of silica or quartz or carbonate sand in a granulometry ranging from 0 to 30 mm in diameter;

• 300 kg/m³ of metallic sand;

• 100 kg/m³ of silica or quartz or carbonate sand in a granulometry ranging from 1 to 6 mm in diameter.

Such an artificial conglomerate can be advantageously used to provide a conductive coating of a radiant system (figure 1) of the type described in the international patent application WO2010086886, which can be applied in a new building or, alternatively, in a climatic renovation of a yet existing building, both residential, public, commercial and industrial .

In particular, the various applications of such a product are possible in any use destination where reduced overall dimensions and mostly the lowest impact as possible are necessary, in order to get conditioning and/or defrosting of the surface, and also the renovation of the surface from the mechanical point of view, whose maintenance over time becomes even less expensive and invasive.

One of the climatic renovation at low temperature which has been possible up to now is that one of the companies performing production (industry, commercial, hotel, hospital, school etc.) : the difficulty of operating with a limited thickness panel and having a surface able to immediately bear any use condition (without the long times of grip of the materials used) , is easily overcome thanks to the mechanical features of the conglomerate according to the invention which becomes the only solution, at dry assembly, able to be used in any environment, even the most aggressive (mountain and sea) one at high environment humidity (wines vault, under and counter soil environment etc.).

The features of the artificial conglomerate according to the invention makes it a remarkable diffuser, but also a relevant catcher of solar energy, therefore it is possible to provide a prefabricated module able to operate even in this circle.

Example 2

A second embodiment of the artificial conglomerate of the invention provides the following doses: • 200 kg/m³ of white concrete;

• 50 L/m³ of water-catalyzed epoxy resin;

• 1000 kg/m³ of rubber aggregate, in a granulometry ranging from 0 to 4 mm in diameter;

• 500 kg/m³ of silica or quartz o carbonate or similar sands, in a granulometry ranging from 0 to 30 mm in diameter;

• 600 kg/m³ of metallic sand.

The artificial conglomerate thus obtained finds application in arranging prefabricated load-bearing structures in building field, such as for example pillars, or beams or plinths (figure 2) .

Elasticity of rubber advantageously allows to absorb the movements without running into destructive tractions (thermal movements, settling of the rest plane, seism) and the seismic vibrations, favouring the movements due to stresses, and allows to totally eliminate the need for a metallic, extremely expensive reinforcement. By using a proper aggregate mixture, it will be possible to create articulations and pre-stressed structures in order to absorb the mechanical-dimensional variations by exploiting the elasticity and elastic memory itself of the conglomerate. In detail, the material obtained presents highh cohesion and elasticity, and its yield and breakage point cannot be approximated to the concrete behavior, but to the iron one. The applications in the field of the prefabricates are several and could produce beneficent effects on the weight and deformability of the structure; applications for acoustics and for modifying rigidity of the structural articulations, absence of porosities which allows greater duration of the reinforcements wires, allows its use in very aggressive environments, where salts and ice are destructive for the porous concretes. Example 3

A third embodiment of the artificial conglomerate according to the invention provides the following doses:

• 300 kg/m³ of anhydrite;

• 35 L/m³ of water-catalyzed epoxy resin;

• 1000 kg/m³ of rubber aggregate, having a granulometry which can vary in the range between 0 and 4 mm in diameter;

• 500 kg/m³ of silica or quartz or carbonate or the like sand, having a granulometry which can vary in the range between 0 and 30 mm in diameter;

• 600 kg/m³ of metallic sand.

Example 4

A fourth embodiment of the artificial conglomerate of the invention provides the following doses:

• 50 kg/m³ of white concrete;

• 70 L/m³ of water-catalyzed epoxy resin;

• 700 kg/m³ of rubber aggregate, having a granulometry which can vary in the range between 0 and 3 mm in diameter;

• 100 kg/m³ of silica or quartz or carbonate or the like sand, having a granulometry which can vary in the range between 0 and 30 mm in diameter;

• 100 kg/m³ of expanded clay, having a granulometry of 2 mm diameter.

In this case, the artificial conglomerate obtained can be used in preparing of an insulating base, both under the acoustic point of view and under the thermal point of view, which can be for example applied in laying pipes of heating plants or in climatic renovations of existing buildings. The technical features of the aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity and the technical features of the artificial conglomerate thus prepared, both object of the current invention, as well as the resulting advantages, are, then, evident from the description just made.

It is, finally, clear that several other changes could be made to the aggregate mixture for preparing an artificial conglomerate and the artificial conglomerate thus prepared concerned, without departing from the principle of novelty intrinsic in the inventive idea expressed herein, as it is clear that, in the practical implementation of the invention, materials, shapes and sizes of the illustrated details could be changed, as needed, and replaced with others technically equivalent .

Claims

1. Aggregate mixture for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity comprising :

- an amount ranging between 0.1 and 2,500 kg/m³ of at least one of the following sands: silica, quartz, carbonate or similar;

- an amount of rubber aggregate ranging between 10 and 1,200 kg/m³,

characterized in that it includes an amount ranging between 0.1 and 1,000 kg/m³ of mineral aggregates of metallic nature.

2. Aggregate mixture according to claim 1, characterized in that said rubber aggregate is obtained by triturating and treating tyres.

3. Aggregate mixture according to claim 2, characterized in that said rubber aggregate has a granulometry not exceeding 8 mm in diameter.

4. Aggregate mixture according to any of the previous claims, characterized in that an amount ranging between 0.1 and 1,500 kg/m³ of said sands has a granulometry not exceeding 30 mm in diameter .

5. Aggregate mixture according to any of the previous claims, characterized in that an amount ranging between 0.1 and 1,000 kg/m³ of said sands has a granulometry in the values range of 1÷6 mm in diameter.

6. Aggregate mixture according to any of the previous claims, characterized in that said mineral aggregates of metallic nature have a granulometry not exceeding 6 mm in diameter.

7. Aggregate mixture according to claim 6, characterized in that said aggregates of metallic nature include any of the aggregates selected from the group consisting of an aggregate of corundum, aggregate of copper, aggregate of zinc, aggregate of aluminium, graphite or the like.

8. Aggregate mixture according to any of the claims from 1 to

7, characterized in that it includes, in an amount ranging between 0.1 and 600 kg/m³, water-repellent expanded clay aggregates having a granulometry not exceeding 6 mm in diameter .

9. Aggregate mixture according to any of the claims from 1 to

8, characterized in that it includes, in an amount ranging between 0.1 and 600 kg/m³, aggregates of pumice stone having a granulometry not exceeding 20 mm in diameter.

10. Aggregate mixture according to any of the claims from 1 to 9, characterized in that it comprises glass spheres in an amount ranging between 0.1 and 100 kg/m³.

11. Artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity characterized in that it includes:

- an aggregate mixture according to any of the previous claims ;

- a natural binder, in an amount ranging from 0.1 and 500 kg/m³, suitable to harden said aggregate mixture.

12. Artificial conglomerate according to claim 11, characterized in that said natural binder is any of the binders selected from the group consisting in hydraulic binder, in a maximum amount of 400 kg/m³, air-hardening binder or the like.

13. Artificial conglomerate according to claim 12 characterized in that said air-hardening binder is anhydrite.

14. Artificial conglomerate according to any of the claims from 11 to 13, characterized in that it comprises a synthetic binder, in an amount ranging between 0.1 and 400 1/m³, suitable to harden said aggregate mixture.

15. Artificial conglomerate according to claim 14, characterized in that said synthetic binder is water- catalyzed, in a maximum amount of 250 1/m³, and includes at least one of the following resins: epoxy resin, polyurethane resin, vinyl resin, acrylic resin or similar.

16. Artificial conglomerate according to claim 14, characterized in that said synthetic binder is solvent- catalyzed .

17. Artificial conglomerate according to any of the claims from 11 to 16, characterized in that it comprises, in an amount ranging between 0.1 and 1 kg/m³, a reinforcement grating made up of fibrillated fibres, said grating having a module with a side length ranging between 5 and 50 mm.

18. Artificial conglomerate according to claim 18, characterized in that said fibres are made up of polypropylene and said module presents a side length ranging between 5 and 40 mm.

19. Artificial conglomerate according to claim 18, characterized in that said fibre are made up of glass and said module present a side length ranging between 5 and 40 mm.

20. Artificial conglomerate according to claim 17, characterized in that said fibre are made up of metal.

21. Use of an aggregate mixture according to any of the claims from 1) to 10) for preparing an artificial conglomerate having high properties of deformability and mechanical strength and with relevant thermo-conductive capacity .