FR2817274A1 - Heat-insulating wall cladding element comprises thin outer layer with natural surface finish and thick inner layer containing polystyrene balls - Google Patents

Abstract

A wall cladding element comprises a thin outer part comprising a sand/binder mortar with a surface finish like that of a natural material such as stone, and a thicker inner part comprising small expanded polystyrene balls embedded in a mortar of the same kind as in the outer part. An Independent claim is also included for the production of the wall cladding element, comprising filling a mold with a mixture of the mortar and polystyrene balls, vibrating the mold to cause the balls to rise from the bottom, allowing the mortar to set, and removing the product from the mold.

Description

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The present invention relates to a thermally insulating facade cladding element and its manufacturing process.

There are already known covering elements which are placed on the facades of buildings to isolate them from cold and humidity, but which have the drawback of having a very different appearance from that of traditional materials such as stone.

The present invention makes it possible to obtain facade cladding elements which are simple to produce, the appearance of which corresponds to the traditional material which one chooses, and which ensure good thermal insulation of the building while constituting an effective barrier against the 'humidity.

In addition, this coating, which is light in weight, can be easily attached to facades using mortars or grout of lime or cement, or even traditional glues.

The facade cladding element according to the invention is characterized in that it comprises: a thin external part constituted by a mortar based on sand and binder, the front face of which has a finish which may correspond in the appearance of a natural element such as stone, said mortar possibly containing an additive, preferably mineral, which gives it its color, and an internal part of greater thickness which is constituted by beads of expanded polystyrene small diameter, coated in a mortar of the same kind as that of the external part of the element.

The binder incorporated into the sand to make the mortar can consist, for example, of cement, lime or a mixture of the two.

According to a preferred embodiment of the invention, the mortar also contains a reinforcing resin such as a melamine or naphthalene derivative, which polymerizes during setting of the mortar.

It is also possible to add a conventional type waterproofing agent to the mortar.

According to the invention, the mortar preferably comprises approximately from one to six parts of sand for two parts of binder.

The polystyrene beads advantageously have a diameter of the order of 2 to 4 millimeters.

They are preferably incorporated into the mortar at the rate of approximately one volume of binder for 2 to 4 volumes of binder.

The reinforcing resin and the water repellent can be added to the mortar at the rate of a few percent according to their specific characteristics.

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 The moisture uptake of the elements according to the invention, that is to say the amount of water which they are capable of absorbing when immersed in this liquid, is a few percent.

The present invention also relates to a process for manufacturing a facade element, characterized by the fact that a mixture consisting of a mortar based on sand and a binder and by balls of balls is placed in a mold of desired shape. small diameter expanded polystyrene; that the whole is vibrated for a sufficient time to allow the polystyrene beads to rise in the mixture so as not to occupy the lower part of the mold; let the mortar have time to set; and that the facade element thus obtained is removed from the mold.

According to a preferred embodiment of the invention, a mortar is used which contains approximately one volume of water for one to two volumes of binder. In general, it is preferable to limit the volume of water to that which is necessary for setting the binder, so as to prevent the polystyrene beads from rising spontaneously or too quickly during the vibration.

The vibration of the mixture can be carried out on a conventional vibrating table for a time of approximately 1 to 3 seconds, depending on the viscosity of the initial mixture and the thickness desired for the external layer of the element which is free of polystyrene beads.

An extension of the duration of the vibration has the effect of increasing the thickness of the external layer of the element, and vice versa.

To obtain a surface appearance similar to that of a given natural material, such as stone, rubble stone or bricks, it is advantageous to use a mold, the bottom of which is formed by a molding, for example of a base material. silicone, which is conventionally obtained from the corresponding natural material.

The mortar can be colored by adding sand, mineral or synthetic pigments, or dyes.

In order to better understand the invention, we will now describe several modes of implementation given by way of non-limiting examples.

EXAMPLE 1 To make an insulating facade cladding element, imitating cut stone, the face of a stone or a group of several natural stones is molded using a silicone-based elastomer. whose joints have been stripped to a depth of about 2 cm.

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 This molding is placed in the bottom of a mold whose surface corresponds to that of the stone or group of stones, and whose height of 6 cm corresponds to the thickness which it is desired to give to the covering element .

The following mixture is produced: - 3 volumes of sand with a particle size of 0 to 1.5 mm, having the color of the stone that one wishes to imitate, - 1 volume of cement, - 3 volumes of expanded polystyrene beads of 3 mm in diameter such as those sold under the brand BETOSTIREN, - 2% of polymerizable resin such as that known under the brand
ADDIFOR PLAST, - 1.5% of water-repellent product according to standard NFP 18 334 such as that sold under the brand IMPER BETON, - 1 volume of water, which is stirred to make it homogeneous.

The mixture is poured into the mold which is placed for 3 seconds on a vibrating table to make the expanded polystyrene beads rise upwards and thus produce at its lower part the outer layer of the manufactured element which does not contain polystyrene beads. This layer has a thickness of about 12 mm.

We wait for the mortar to set and we unmold.

There is thus obtained according to the invention a coating element which in the appearance of the stone or group of stones used for molding, which is a good thermal insulator and which constitutes an effective barrier against humidity.

One can thus clad a brick or concrete block wall by gluing a series of elements such as the one just described, but which are preferably made from different stones.

Then simply join the elements thus glued as we would with natural stones, to obtain a facade perfectly reproducing natural stones.

The elements according to the invention also have the important advantage of being much lighter than traditional coatings in massive reconstituted stone.

Thanks to their lightness, the elements according to the invention can be grouped together by being glued by their rear face to a net, or a mesh, for example made of plastic or metal.

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Such an assembly facilitates their installation and their marketing packaging, the net or the mesh being coated in the glue or in the coating during installation on the facade.

Example II To make a facade cladding element having the appearance of a wall produced using uncut rough stones, such a wall is chosen, an area of which is delimited along certain stones whose joints have been dug. from 1 to 3 cm.

A molding is carried out which is placed in an 8 cm high mold, as indicated in Example 1.

The following mixture is produced: - 2 volumes of sand with a particle size of 0 to 2 mm, - 1% of a mineral pigment having the color of the stone which it is desired to imitate, - 1 volume of cement, - 1 volume of quicklime, - 4 volumes of expanded polystyrene beads 4 mm in diameter such as those sold under the brand BETOSTIREN, - 4% of polymerizable resin based on melamine derivative such as that known under the brand ADDIFOR PLAST, - 1 % of water repellent product according to standard NFP 18 334 such as that sold under the brand IMPER BETON, - 2 volumes of water, which is stirred to make it homogeneous.

The mold is placed on a vibrating table for 1.5 seconds, which makes it possible to obtain at its lower part the outer layer of the manufactured element which does not contain polystyrene beads.

This layer has a thickness of about 15 mm.

Let the setting take place and unmold the element which has a thickness of 8 cm.

We glue the element obtained on the facade by assembling it with other similar elements and we join it as we would with natural stones.

 Free fit To make a facade element having a flat exterior surface, a molding of such a surface is made, which can for example be a fine coating,

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 a polished surface, or a slightly worked surface.

This molding is placed in a mold as indicated in the preceding examples.

And a mixture is used having the following composition: - 1 volume of sand with a particle size of 0 to 2 mm, - 1 volume of cement, - 2 volumes of polystyrene beads 4 mm in diameter, - 1% of polymerizable resin sold under the name of ADDIFORPLAST, - 1/2 volume of water This mixture is placed in the mold where it is vibrated for 1 second.

à 3 mm d'épaisseur. After setting, an element is obtained with an outer layer without beads of 2

3 mm thick.

Example IV To make a facade element, proceed as indicated in Example 1, but using the following mixture: - 2 volumes of sand with a particle size of 0 to 2 mm, - 1 volume of cement, - 3 volumes of beads of 2.5 mm polystyrene, - 2% of resin sold under the ADDIFORPLAST brand, - 1.5% of water-repellent product, - 1 volume of water, With a vibration time, a massive external layer of 2 to 4 mm is obtained Example V To make a facade element, proceed as indicated in Example II, but using the following mixture: - 2 volumes of sand with a particle size of 0 to 2 mm, - 1 volume of quicklime, - 4 volumes of 3 mm polystyrene, - 3% resin sold under the brand ADDIFORPLAST, - 1.5% water-repellent product, - 1 volume of water.

With a vibration time of 5 seconds, a massive outer layer of 5 to 10 mm is obtained.

It is understood that the embodiments of the invention which have been described above have no limiting character and that they can be modified or adapted without departing from the scope of the invention.

Claims (10)

 1.-facade cladding element characterized by the fact that it comprises in combination an external thin part constituted by a mortar based on sand and binder, the front face of which has a finish which may correspond to the aspect of a natural element such as stone, and an internal part of greater thickness which is constituted by expanded polystyrene balls of small diameter coated in a mortar of the same kind as that of the external part.  2. -Element according to claim 1 characterized in that the mortar also contains an additive, preferably mineral which gives it the color of the element it must imitate.  3. -Element according to any one of claims 1 and 2 characterized in that the binder consists of cement, lime or a mixture of the two.  4. -Element according to any one of claims 1 to 3 characterized in that the mortar also contains a reinforcing resin which polymerizes during setting of the mortar.  5. -Element according to any one of claims 1 to 4 characterized in that the mortar contains a waterproofing agent.  6. -Element according to any one of claims 1 to 5 characterized in that the mortar comprises about one to six parts of sand for two parts of binder.  7. -Element according to any one of claims 1 to 6 characterized in that the polystyrene balls have a diameter of 2 to 4 millimeters.  8. -Element according to any one of claims there 7 characterized in that the polystyrene beads are incorporated into the mortar at a rate of about one volume of mortar for one to three volumes of beads.  9. Process for manufacturing a facade element according to any one of the preceding claims, characterized in that a mixture constituted by the mortar based on sand and binder is placed in a mold of desired shape, as well as by expanded polystyrene beads; that the whole is vibrated for a sufficient time to allow the polystyrene beads to rise in the mixture so as not to occupy the lower part of the mold; let the mortar have time to set; and that the facade element thus obtained is removed from the mold.  10. -Process for manufacturing a facade element according to claim 9, characterized in that one vibrates the mixture on a table <Desc / Clms Page number 7>  vibrating for a time of approximately 1 to 4 seconds, depending on the viscosity of the initial mixture and the thickness desired for the external layer of the element which is free of polystyrene beads.