WO2003040054A1

WO2003040054A1 - Geopolymer stone for building and decoration and method for obtaining same

Info

Publication number: WO2003040054A1
Application number: PCT/FR2002/003815
Authority: WO
Inventors: Joseph Davidovits; François WAENDENDRIES; Ralph Davidovits
Original assignee: Cordi-Geopolymere Sa
Priority date: 2001-11-08
Filing date: 2002-11-07
Publication date: 2003-05-15

Abstract

The invention concerns a geopolymer stone for building and decoration, similar in appearance to natural stone. It consists of: 65 to 95 wt. % of residual rock derived from a naturally weathered rock and/or dendrital rock derived from erosion; 5 to 25 wt. % of geopolymer binder of poly(sialate), poly(sialate-siloxo) and/or poly(sialate-disiloxo) type. Said geopolymer stone is for example sandstone similar to natural rocks belonging to the category of silicious cement or pellitic cement sandstones, or foraminiferous limestone similar to natural rock belonging to the category of limestones with organisms, or arkose-type granite similar to natural stone belonging to the category of arkoses. The geopolymer stone is used as outdoor and/or indoor covering with Portland cement concrete core, dense or expanded (cellular concrete).

Description

Geopolymeric stone for construction and decoration, and process for obtaining it.

Description

The present invention relates to a new type of reconstituted stone intended for construction and decoration. This reconstituted stone is called geopolymeric stone because the agglomeration binder is based on mineral geopolymer, consisting of alkaline aluminosilicates, better known under the name of poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo).

Prior techniques.

The reconstituted stones are in the prior art manufactured by agglomerating mineral fillers either with organic binders or with hydraulic binders based on lime and Portland cement. The stones made with organic binders cannot be intended for an external use because it is known that the matrix in organic resin does not resist UV and IR radiations. This type of stone is found mainly in the form of "artificial marble" slabs, inside buildings. The stones reconstituted using hydraulic binders are UV and IR stable and are used outdoors, but their decorative appearance is relatively poor. But, being made up of matrices sensitive to the chemical attack of acids, these stones, generally limestone-based, are very quickly attacked by atmospheric pollution.

The binders based on mineral geopolymer, consisting of alkaline alumino-silicates, better known under the name of poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo), do not have the defects presented by organic binders and traditional hydraulic binders. They are UV and IR stable, and are very resistant to acids. The term poly (sialate) has been proposed to designate the aluminosilicate geopolymers. The sialate network is made up of SiO ₄ and AlO ₄ tetrahedra alternately linked by oxygen atoms. The cations (Na ⁺ , K ⁺ , Ca ⁺⁺ , H ₃ O ⁺ ) present in the structural cavities of the poly (sialate) balance the negative charge of Al ⁺ in coordination (IV). The empirical formula of the Polysialates is: M _n {- (SiO ₂ ) _z -AIO ₂ } _n , wH ₂ O, with M representing the cation K, Na or Ca and "n" the degree of polymerization; “Z” is equal to 1, 2, 3 or more, up to 32. The polymers with three-dimensional (3D) network are of the type: Poly (sialate) _n - (- Si-0-Al-0-) _n M-PS Si: Al = l: l

Poly (sialate-siloxo) M _n - (Si-O-Al-O-Si-O-) _n M-PSS Si: Al = 2: l

Poly (sialate-disiloxo) M _n - (Si-O-AI-O-Si-O-Si-O-) _n M-PSDS Si: Al = 3: l

Poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type geopolymers have been the subject of several patents highlighting their particular properties. We can cite for example the French patents: FR 2,489,290, 2,489,291, 2,528,818, 2,621,260, 2,659,319, 2,666,253, 2,758,323. Using various mineral fillers, with geopolymers, we made various decorative objects, such as molded objects (statues, bas-reliefs) or floor and wall coverings as described in the French utility certificate 2.528.818. However, the final material obtained does not reproduce the characteristics of a natural stone. More generally, the mineral filler has a fine particle size, because experience shows that the use of large fillers (between 1 mm and 10 mm) is irreparably accompanied by a "concrete" appearance. In fact, as use is made of ground and selected materials, the angular shape of the grains does not allow optimum densification to be obtained, always leaving a non-crystalline zone between the grains visible.

On the contrary, in the context of the present invention, naturally altered residual rocks and / or detrital rocks, not ground, are used, making it possible to produce a stone in which this non-crystalline zone is no longer seen. In the optical examination of thin sections cut in the geopolymeric stones produced according to the invention, the petrographer generally sees only the crystalline parts of the original materials. The geopolymeric binder is completely amorphous, even in polarized light, and cannot be detected by conventional means of optical microscopy.

Statement of the invention:

The main object of the invention is to manufacture a geopolymeric stone for construction and decoration, having an appearance similar to natural stone. In what follows we use the following geological and petrographic definitions taken from the book “Précis de Pétrographie” by Jean Yung, Masson and Cie Editeurs, Paris, 1969:

- weathered rock: rock that has undergone surface weathering mainly due to the infiltration of acidic water (rainwater, humic acids). -residual rock: the surface alteration gives rise to two kinds of substances, some solid, others spent in solution. The solid substances accumulated on site form a residual rock.

- erosion: unlike weathering, a chemical phenomenon, erosion uses only mechanical processes: alternating dryness and humidity and sudden variations in temperature, which lead to physical disintegration of old materials producing an arena detrital.

- detrital rock: the detrital arenas accumulated on the spot form a detrital rock - arkose: variety of feldspar sandstone in which, next to quartz grains, the mineral feldspar occurs in grain whose size is similar to that of granite feldspar 'origin.

- sandstone with pellitic cement: alongside quartz grains, there are many grains of feldspar, as well as microconglomeric grains of hard rocks, composite grains. The cement is made of dust of quartz particles, feldspar, mica, kaolinite.

- arena: in regions with a temperate climate, granites and sandstones are commonly transformed, by surface alteration, into a sandy rock or sand, called an arena. In regions with a hot and dry climate, plutonic and igneous rocks are transformed by erosion into a detrital arena.

- test: shell, shell, limestone shell of molluscs and crustaceans.

The main object of the invention is the description of geopolymeric stones for construction and decoration, analogous in appearance to natural stone, which consist of 65 to 95% by weight of residual rock originating from a naturally occurring rock weathered and / or detrital rock from erosion, and from 5 to 35% by weight of geopolymeric binder of poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type.

Geopolymeric stones of sandstone analogous to natural rocks belonging to the class of sandstones with siliceous cement or sandstones with pellitic cement consist of 65 to 95% by weight of quartz and / or feldspar arena, and from 5 to 35% by weight of geopolymeric binder of poly (sialate), poly (sialate-siloxo) and or poly (sialate-disiloxo) type.

Geopolymeric limestones of the limestone type with foraminifera, similar to natural rocks belonging to the class of limestones with organisms, consist of 65 to 95% by weight of a mixture of tests and calcareous sand, and from 5 to 35% by weight of geopolymeric binder of the poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type . Among the rocks with a granitic aspect, the geopolymeric stones are of the arkose type, that is to say analogous to natural rocks belonging to the class of arkoses. They consist of 65 to 95% by weight of granite arena and 5 to 35% by weight of geopolymeric binder of poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type.

A second subject of the invention is the description of geopolymeric stones serving as an external and / or internal coating for a Portland cement concrete core and / or expanded concrete (cellular concrete).

Aerated concrete has the following advantages and qualities. The blocks can be load-bearing, insulating, water-repellent, light to handle. Cellular concrete makes it possible to make clean sites, because it suffices to mix an adhesive and to mount the wall. No need for a concrete mixer, a pile of sand, Portland cement with dosing problems. However, we have always deplored their fragility and the obligation to provide them with a finishing coating after the break. For this, we return to the traditional problems of the site: protection, scaffolding, machine for projecting, manual finishing, to which are added the problems linked to bad weather. What solutions are currently used. Their surface is protected by gluing or stapling over bricks, facing stones, sandstone tiles. Alternatively, water-repellent coatings are projected whose lifespan, in order to preserve a satisfactory appearance with pollution from cities, is of the order of 12 to 15 years. It is also covered with thin coatings similar to microporous paints. In no case does the block appear in its finished surface appearance.

For a long time, we have been looking for a finish that can be made in the factory which would make it possible to mount a finished and insulated load-bearing wall in a single installation operation and without thermal bridge. It would only remain for the painter sheltered from the weather to coat and paint the interior in a decorative manner, the building being finished externally, hence the interest of the present invention as detailed below. Not only does geopolymer stone offer all the guarantees of a natural stone (limestone, granite, sandstone, etc.), but also a final aspect which can, by molding, take over any shape, copy of old or contemporary creation . The finishing joint can also be made directly upwards, provided that the cellular concrete adhesive is compatible and slightly tinted for the desired appearance. Best Ways to Carry Out the Invention

To produce a geopolymeric stone according to the invention, preference is not given to using geological materials which are mechanically ground in the factory, as is traditionally the case in the manufacture of "artificial marbles". Preferably, the geopolymeric stone according to the invention is obtained by using residual rocks and / or detrital rocks which are used as extracted from the ground, or at most after having undergone a simple dust washing operation. Preferably, there is no grinding, at most a disintegration of the clods, to facilitate washing and elimination of parasitic materials (earth, humus, etc.). To manufacture a geopolymeric stone according to the present invention, a geopolymeric mixture containing: a) 65 to 95% by weight of residual rock coming from a naturally weathered rock and / or detritic rock coming from erosion is hardened; b) 5 to 35% by weight of a geopolymeric resin of sodium, potassium and calcium alumino-silicates generating, after hardening, a geopolymeric binder of poly (sialate), poly (sialate-siloxo) type and / or poly (sialate-disiloxo).

The geopolymeric stones of the invention as well as their manufacturing process are illustrated by the following Examples. These examples are not limiting on the overall scope of the invention as presented in the claims. All parts shown are by weight.

Example 1:

We use a machine used daily to make artificial marble or artificial granite tiles. This machine consists of a hydraulic press in which there is also a vibrating table as well as a vacuum bell. The aggregates are crushed and crushed granite with an optimal grain size in order to leave the least vacuum between the grains. The vibrating table makes it possible to place the grains and the vacuum bell to eliminate the air bubbles included in the binder. For artificial marble, the binder is an organic resin (acrylic or polyester) and for artificial granite, the binder is hydraulic cement. Instead of these traditional binders, a geopolymeric cement of the (K, Ca) - Poly (sialate-siloxo) type is now used, such as that described in French patent FR 2666253. 80 parts of aggregates are mixed with 18 parts of geopolymeric cement and 2 parts of black pigment. We place everything in the mold and then under the vibrating press, and apply the vacuum. The compressed tile is then left to harden to 60 deg. C for 2 hours. Then we proceed to the finishing operation which consists of sanding and then polishing. We obtain a geopolymer stone tile which is artificial granite, black in color. In the structure, an amorphous phase consisting of cement and fines is clearly distinguished between the angular grains.

Example 2: A mixture containing 484 parts of ground granite, the particle size of which ranges from 0.05 mm to 7 mm, is made, with 90 parts of geopolymeric cement (K, Ca) - (poly (sialate-siloxo) and 30 parts of water. This mixture is introduced into a mold under which a vibration is applied to allow good compaction. It is hardened for one day at room temperature and then unmolded. The geopolymer stone is then left in a closed plastic bag for 1 week. The structure of the stone is similar to that of Example 1: a clear distinction is made between angular grains, an amorphous phase consisting of cement and fines.

Example 3: In a highly altered granite deposit where very advanced kaolinization gives rise to a kaolin separation industry, a granite arena is chosen which contains less than 10% by weight of kaolinite. This granite arena consists of free quartz grains, free feldspathic grains, free muscovite mica and residual kaolinite. A mixture containing 500 parts of this granite arena is made with 100 parts of geopolymeric cement (, Ca) - (poly (sialate-siloxo) and 30 parts of water. It is hardened at 80 ° C. for 2 hours and then unmolded. The stone is then left in a closed plastic bag for 1 week, it is cut with a diamond saw The structure of the geopolymeric stone is different from that of examples 1 and 2: an extremely dense crystalline structure is obtained, each grain being coated with a thin amorphous layer of kaolinite transformed into tecto-alumino-silicate by geopolymerization The geopolymeric stone obtained is of the arkose type. Example 4:

The procedure is as in Example 3, but instead of taking the granite arena, the kaolin extraction residue is used. In fact, when the granite arena is rich in kaolin (of the order of 30% by weight for example), this kaolin is extracted by decantation in water. The remaining heavy parts constitute a residual granite arena containing at most 2% by weight of kaolin. This residue is used as in Example 3. The structure of the stone is different from that of Examples 1 and 2; it is similar to that of Example 3; each grain is coated with a very thin amorphous layer of geopolymeric binder. The resulting stone is of the arkose type. To make a limestone geopolymer stone, you will choose a naturally weathered shell limestone. For example, to make a foraminiferous limestone of the nummulite type, a mixture containing 65 to 95% by weight of naturally altered limestone, not ground, consisting of free tests and calcareous sand with free tests, with 5 to 35% by weight, will be hardened. a geopolymeric resin of sodium, potassium and calcium alumino-silicates generating, after hardening, a geopolymeric binder of the poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type.

In the case of fine-textured sandstones, a deposit of quartz arena (or quartz sand) that is not very consolidated is preferably chosen, which breaks up easily by simple pressure. The addition of geopolymeric cement results in the manufacture of a sandstone with siliceous cement or more especially of a sandstone with pellitic cement.

The detrital arenas and very poorly consolidated detrital rocks, for example of the basalt type and other plutonic and igneous rocks, make it possible to obtain natural stones imitating certain metamorphic rocks.

Geopolymeric stones can be used as decorative or protective coating, in statuary and other decorative object. In construction they can be used as exterior cladding, in the form of tiles, blocks, bricks. You can also put the geopolymeric mixture at the bottom of the mold and pour on it either traditional Portland cement concrete or aerated concrete, or apply a block of dense or cellular concrete already hardened. The connecting element between the geopolymeric stone layer and the core of dense or cellular Portland cement concrete is the geopolymeric binder. Example 5:

The geopolymeric mixture of one of the preceding examples 1 to 4 is gradually poured into a mold made either of plaster, wood, metal, elastomer, plastic, or other, and packed, vibrated in order to evacuate the air bubbles. On the upper surface, where the excess binder floats, is placed the block of cellular concrete, clean and previously scratched for better adhesion. We vibrate and we pack everything, without damaging the block. Then hardened the geopolymeric reaction. After demolding, sand or brush with a wire brush or pass the "railway", depending on the desired finish. If necessary, and under certain conditions, a transparent anti-graffiti product will be used. This gives a natural-looking stone block on the outside and insulating on the inside. To speed up setting, the operation of laying aerated concrete on the excess binder can be done at the exit of the autoclave, the block still hot.

Instead of a block of dense concrete or aerated concrete, already hardened, one can also pour on the surface of the geopolymeric mixture, fresh concrete of Portland cement or a cellular concrete ready for expansion. The hardening of the core of Portland cement concrete takes place under the same conditions as that of geopolymeric stone.

In addition, with the aim of better integrating construction into the local built environment, knowing that there are residual rocks or quarry rocks in almost all regions, the choice will focus on the closest aspect of local traditional architecture.

Of course, various modifications can be made by those skilled in the art to the geopolymeric methods and stones which have just been described by way of example, without departing from the scope of the invention.

Claims

Claims:

1) Geopolymeric stone for construction and decoration, analogous in appearance to natural stone, characterized in that it consists of: a) 65 to 95% by weight of residual rock from a naturally weathered rock and / or detrital rock from erosion; b) 5 to 35% by weight of geopolymeric binder of the poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type.

2) Geopolymeric stone for construction and decoration according to claim 1), characterized in that it constitutes the exterior and / or interior decorative coating of a concrete block based on Portland cement, and that the connection between the concrete core and the geopolymeric stone face is produced by the so-called geopolymeric binder.

3) Geopolymeric stone for construction and decoration according to claim 1), characterized in that it constitutes the exterior and / or interior decorative coating of a block of expanded concrete (aerated concrete), and that the connection between the cellular concrete core and the geopolymeric stone face is produced by the so-called geopolymeric binder.

4) Geopolymeric stone in sandstone, according to any one of claims 1, 2 or 3, analogous to natural rocks belonging to the class of sandstones with siliceous cement or sandstones with pellitic cement, characterized in that it consists of: a) 65 to 95% by weight of quartz and / or feldspar arena (sand); b) 5 to 35% by weight of geopolymeric binder of the poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type.

5) limestone geopolymeric foraminifera according to any one of claims 1, 2 or 3, analogous to natural rock belonging to the class of limestones with organisms, characterized in that it consists of: a) 65 to 95% by weight of a mixture of tests and limestone sand; b) 5 to 35% by weight of geopolymeric binder of the poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type. 6) Geopolymeric granite stone of arkose type, according to any one of claims 1, 2 or 3, analogous to natural rock belonging to the class of arkoses, characterized in that it consists of: a) 65 to 95 % by weight of granite arena; b) 5 to 35% by weight of geopolymeric binder of the poly (sialate), poly (sialate-siloxo) and / or poly (sialate-disiloxo) type.

7) A method of manufacturing a geopolymeric stone according to claim 1), characterized in that this stone is obtained by hardening a geopolymeric mixture containing: a) 65 to 95% by weight of residual rock originating from a naturally occurring rock weathered and / or detrital rock from erosion; b) 5 to 35% by weight of a geopolymeric resin of sodium, potassium and calcium alumino-silicates generating, after hardening, a geopolymeric binder of poly (sialate), poly (sialate-siloxo) type and / or poly (sialate-disiloxo).

8) Method for manufacturing a geopolymer stone in sandstone with siliceous cement or in sandstone with pellitic cement, according to claim 4) and claim 7), characterized in that these sandstones are obtained by hardening a geopolymeric mixture containing: a) 65 to 95% by weight of quartz and / or feldspar arena (sand); b) 5 to 35% by weight of a geopolymeric resin of sodium, potassium and calcium alumino-silicates generating, after hardening, a geopolymeric binder of poly (sialate), poly (sialate-siloxo) type and / or poly (sialate-disiloxo).

9) Process for manufacturing a geopolymeric limestone according to claim 5) and claim 7), characterized in that when the foraminiferous is of the nummulite type, this nummulitic limestone is obtained by hardening a geopolymeric mixture containing: ) 65 to 95% by weight of naturally altered limestone, consisting of - free tests

- limestone sand with free tests b) 5 to 35% by weight of a geopolymeric resin of sodium, potassium and calcium alumino-silicates generating, after hardening, a geopolymeric binder of poly (sialate), poly (sialate-siloxo) type and / or poly (sialate-disiloxo).

10) Process for manufacturing a geopolymeric granite stone of arkose type according to claim 6) and claim 7), characterized in that this arkose granite stone is obtained by hardening a geopolymeric mixture containing: a) 65 to 95 % by weight of naturally altered granite arena, consisting

- free quartz grains, - free feldspathic grains,

- free mica (muscovite and / or biotite),

- residual kaolinite, b) 5 to 35% by weight of a geopolymeric resin of sodium, potassium and calcium alumino-silicates generating, after hardening, a geopolymeric binder of poly (sialate), poly (sialate-) type siloxo) and / or poly (sialate-disiloxo).

11) Process for manufacturing a geopolymeric granite stone of the arkose type according to claim 10), characterized in that the granite arena consists of waste resulting from the extraction of kaolin, from naturally altered granites.

12) A method of manufacturing a geopolymeric stone for construction and decoration according to claim 2) and claim 7), characterized in that the said geopolymeric mixture is poured into a mold, then it is packed and vibrated in order to '' evacuate the air bubbles, then, on the upper surface, where the excess geopolymeric binder floats, Portland cement concrete is poured. We vibrate and pack and harden the geopolymeric reaction.

13) A method of manufacturing a geopolymeric stone for construction and decoration according to claim 3) and claim 7), characterized in that the said geopolymeric mixture is poured into a mold, then it is packed and vibrated in order to '' evacuate the air bubbles, then, on the upper surface, where the excess geopolymeric binder floats, a block of cellular concrete is laid, clean and previously scratched for better adhesion. We vibrate and pack and harden the geopolymeric reaction.