Wall structure made of slabstone and serving as carbon dioxide sink containing biomass carbon fibers

Abstract

The invention relates to a relatively thin and fiber-stabilized house wall, by stabilizing the bearing plates (1) to form an intermediate insulation layer for reinforcement over the entire cross-section. The intermediate layer (3) contains pure carbon in the form of biochar or charcoal preferably derived from atmospheric carbon dioxide. The fibers for stabilization are biologically derived carbon fibers and are applied to the inside or outside of the stone slab. And in combination with stone dust which is generated in the production process and has weathering potential, the house wall body has high carbon dioxide negative emission characteristic.

Description

BACKGROUND

[0001] The present invention relates to an innovative wall structure that acts as a carbon dioxide sink (CO2 Sink). The building is based on the principles of EP08874021 and EP20702566 and also employs pressure resistant panels arranged symmetrically. Between these panels, insulation layers are provided to increase the rigidity of the building. Such panels are made of pressure resistant materials that are often brittle and prone to breakage, such as natural stone, artificial stone, concrete, glass or ceramic materials. Such materials include, among others, natural stone such as granite, gneiss, marble, limestone, basalt and feldspar as well as concrete. The surface of such materials will weather and in the process absorb carbon dioxide. SUMMARY

[0002] The object of the present invention is to bind carbon in the insulation material so that the building material becomes a carbon dioxide negative material. Unlike previous patents, the insulation layer of the present application is made of pure BioChar. BioChar is a form of charcoal that is produced by pyrolysis of biomass. In this thermochemical process, organic matter is decomposed in the absence of oxygen at temperatures between 300 and 700 °C. When incorporated into the insulation layer, BioChar provides excellent thermal insulation and reduces the weight of the wall structure. BioChar enables a highly concentrated form of carbon storage.

[0003] The wall is made of thin stone or ceramic panels that have been stabilized by an innovative method that makes them self-supporting. At the same time, the structure is a highly efficient carbon sink. Materials such as gabbro remain dimensionally stable at temperatures up to 1050 °C and only lose a small amount of compressive strength. This property is particularly important for lightweight structures in the event of a fire. The design ensures that the stone panels remain dimensionally stable even in the event of temperature fluctuations and do not warp. By using materials reinforced with BioChar and carbon fibers, carbon is permanently bound, which helps to reduce carbon dioxide in the atmosphere.

[0004] The wall structure consists of two pressure resistant panels with a BioChar insulation layer in between. The panels can be made of natural stone, artificial stone, concrete, ceramic or glass. The BioChar insulation layer is a highly porous layer that is not only lightweight but also provides excellent thermal insulation. The panels are stabilized against tensile and bending stresses with carbon fibers, preferably carbon fibers made of biomass such as BioGlycerol or Lignin. The two load-bearing panels are bonded with temperature-stable mineral binders such as heat-resistant water glass to ensure structural integrity in the event of a fire. By using feldspar or other heat-resistant materials, safety and stability at high temperatures can be further improved.

[0005] To optimize the mechanical strength of the thin plate and minimize the risk of buckling, the structure is integrated with reinforcing ribs made of temperature-resistant material, such as wood, glass or ceramic, to prevent the formation of thermal bridges. The design of such reinforcing ribs allows the load to be distributed evenly over the entire surface of the wall without creating thermal bridges. Another innovative aspect of the invention is the use of rock or mineral dust generated during the manufacturing process of the plate. Such dust generated during the cutting of the plate has a high potential for accelerated weathering, a process that permanently binds atmospheric carbon dioxide to the mineral structure. By using stone suitable for weathering in the wall structure, an additional carbon dioxide sequestration pathway can be provided, which helps to make the construction method climate neutral.

[0006] An innovative wall structure is described in the invention, which is not only mechanically stable and thermally insulating, but also serves as an efficient carbon dioxide sink. By incorporating materials reinforced with biochar and carbon fibers, a sustainable and environmentally friendly construction method is achieved that actively supports carbon dioxide reduction. The structure combines the advantages of natural stone with innovative materials to create a stable and lightweight environmentally friendly wall structure, offering a promising solution for modern sustainable construction structures.

[0007] Unlike EP08874021 and EP20702566, the invention involves the use of pure biochar as a reinforcing insulation layer, which can be supported by rock wool.

[0008] This use mainly involves the incorporation of high-porosity porous carbon in the insulation layer. The role of this carbon is to achieve good thermal insulation, reduce the weight of the insulation layer, and achieve carbon storage in a highly concentrated form.

[0009] The invention proposes a method for the use of thin stone, ceramic, porcelain, artificial stone or concrete slabs, which are stabilized in a sustainable and cost-effective manner and, according to the method of the invention, serve as efficient carbon sinks while at the same time becoming self-supporting wall elements. Previously, such stone, ceramic, glass and other pressure-resistant mineral materials (hereinafter collectively referred to as "ceramic materials") were used only to increase the weight of a building when used as a facade cladding. In the present invention, however, such materials become load-bearing elements of the walls of a house themselves. The insulation layer together with the carbon fibers (for example, when the carbon fibers are made from organic oil or organic lignin) becomes an efficient carbon sink. Stone is able to withstand high temperatures and thus enables the hardening of concrete in the event of a fire. Gabbro remains dimensionally stable up to temperatures of 1050°C. When the wall loses strength due to a fire, even if the gabbro loses its compressive strength and even if it is in the form of a thin slab, it is still able to withstand compressive loads. Existing structural concrete, when formed into a thin slab, is not able to withstand such high loads when it loses all load-bearing capacity due to a fire. This is important for the future possible use of lightweight structures in the construction sector. The bond between the fibers and the stone is achieved by means of temperature-stable water glass, which provides the stone with a sufficiently high support in the event of a fire.

[0010] In addition, it is important that such wall elements are able to remain dimensionally stable over a wide temperature range and that the "bimetallic effect" is suppressed. To achieve this, it is not only necessary to stabilize the porcelain or ceramic tile so that it does not break due to tension, but also to form an expansion profile on the side of the stone that is in contact with the insulation layer that is to be stabilized. The gradient of this profile must be close to zero in order to ensure that the stone tile does not bend to either side, even if it is subjected to temperature fluctuations. In this way, the appearance of the visible surface remains flat so that no depressions are formed.

[0011] The invention ensures that the porcelain remains stable under various thermomechanical stresses and under pure mechanical loads. The stabilization described above can be adjusted to the specific application and load conditions and protects the porcelain from mechanical damage due to cracking, in particular from thermally induced deformations. In addition, it is crucial that dimensional stability is maintained in the case of temperature differences between the interior and exterior wall surfaces and temperature changes on the side affected by weathering. This stability can be further improved by using slabs made from different materials with different coefficients of thermal expansion.

[0012] The key to finding the most suitable insulating material for such self-supporting sandwich wall is to find a material that minimizes the overall thermal expansion coefficient of the inner and outer sheets. Such a material allows the two sheets to remain as uniform as possible, thereby achieving the carbon absorption effect, ensuring good fire resistance, and achieving high insulation capacity. In addition, the material must be dimensionally stable, waterproof, and frost-resistant, and prevent thermal bridge effects. The ideal candidate material for bonding the individual wall units includes a mineral adhesive with a sufficiently high flexibility and tensile strength to withstand load transfer even under fire conditions after bonding to the fiber-reinforced ceramic sheets, preventing buckling or other failure scenarios.

[0013] Here, the core objective is to find the most suitable insulating material for such self-supporting sandwich walls. By making such natural stone slabs (e.g., made of feldspar) twice as load-bearing as equivalent concrete slabs of the same weight, optimal structural stability can be achieved. As a result, a lighter, higher, and more space-saving structure can be achieved compared to conventional concrete and brick structures. In addition to this, weight and space savings can be achieved compared to steel structures. For example, the specific gravity of granite is similar to that of aluminum, 2.7 times lighter than steel, but its compressive strength is extremely close to structural steel. DETAILED DESCRIPTION

[0014] The structural engineering of the wall structure is described below. The invention of the present patent application relates to the field of construction, in particular to building structures. Such building structures generally include commercial buildings, apartment buildings, exhibition halls, halls, and all types of buildings, in particular residential buildings. The core of the invention relates to an innovative technology that builds house walls as building units that combine static load transfer and facade functions and have all the functions of building envelopes. In addition, the building unit meets the corresponding requirements of current standards in physics.

[0015] Such wall elements are prefabricated elements for on-site installation. After installation, a top structure is provided on the wall element. Such wall elements integrate all static and building physics requirements in one sandwich structure. The outer sheets are made of a ceramic or other pressure-resistant material and serve primarily to absorb normal forces (shear forces). The outer sheets can be used directly as a finish, both indoors and outdoors. The core of the sandwich structure is made of a shear-resistant, thermally insulating foam, for example, and is fixedly bonded to the outer sheets. The core absorbs shear forces resulting from bending stresses in such a way that a sufficiently high bending stiffness is produced perpendicular to the wall element, so that the wall element can withstand horizontal loads acting on it, such as wind loads, while at the same time preventing buckling. A load transfer structure made of a highly insulating stone material serves to distribute the vertical loads symmetrically from the floor slab to the sandwich wall element in order to prevent the occurrence of thermally unacceptable thermal bridges. The materials of the sandwich structure interact with special connecting elements in such a way that water and air tightness are ensured. Without additional structural support, the load capacity is > 75 kN / m. Such wall elements are installed as pendulum columns in the floor slab and are supported according to the principle of a pendulum support. The relevant thermal insulation values meet the Swiss "Minergie" standard.

[0016] The sheets are made of a pressure- and shear-resistant, water-resistant material such as concrete, natural stone, glass or ceramic. Such sheets are fixed with reinforcements that strengthen against tensile stresses resulting from thermally induced asymmetric deformations and tensile stresses in the stress distribution area at the load introduction points, which can lead to unpredictable overall brittle fractures. In addition, this also compensates for material and structural defects, so that the best ductile material properties are obtained. The core of the sandwich structure is made of a highly thermally insulating biochar material.

[0017] The load introduction elements are low-thermal-conductivity, pressure- and shear-resistant elements made of stone or wood, or a combination of stone and wood, and are bonded to the stone sheets by means of a mineral adhesive or dovetail, or both.

[0018] The connections between the sheets and the load introduction elements, between the sheets and between the reinforcing ribs are made by means of a shear-resistant, permanent adhesive. This adhesive is a commercially available mineral adhesive, such as a high-temperature-resistant water glass that is resistant to temperatures of at least 600°C.

[0019] In the stabilization of the stone slabs themselves, the invention uses a fiber material with a mineral matrix, such as carbon fibers, preferably made from biomass, which is further preferably bio-glycerol or lignin. Such fibers stabilize the stone material over a large area, or in the form of individual fiber threads, partially, to prevent it from swelling and breaking. The thermal expansion modulus of natural stone is extremely low, and since natural stone is a compressible, porous structure, it is possible to adjust its thermal expansion modulus by stabilizing it with fibers. If the fiber tension is sufficiently high and the type of fiber used is suitable, or if a suitable prestress can be introduced by the fibers in the fiber matrix and stone composite, the swelling of the stone slabs under the influence of temperature can be minimized or even completely eliminated. The invention described herein also relates to carbon fibers made from lignin. Such carbon fibers are less expensive than polyacrylonitrile (PAN) fibers, and when applied to the outside of the stone slabs as tensile reinforcements, they are rigid enough to meet the requirements described herein.

[0020] The thermal expansion modulus of natural stone is extremely low, and since the strength of the fibers described above is sufficient to prevent thermal expansion, it is possible to adjust its thermal expansion modulus by stabilizing it with such fibers. Although lignin-based fibers have a relatively low stiffness, the buckling behavior of such slabs can still be improved by using a fiber matrix on the outer surface of the load-bearing stone slabs, either on one side or on both sides. This innovation is not found in previous patent applications. For aesthetic and protective matrix purposes, the fiber layer can then be covered with a thin stone layer.

[0021] As a result, a compression- and tensile-resistant slab structure is obtained, which in this application ensures that the ceramic material has a sufficiently high stability against cracking and breaking. This symmetrical slab structure (one side: stone slab stabilized with fibers, middle: insulation layer, other side: another stone slab stabilized with fibers) is not only aesthetically pleasing both inside and out, but is also a completely innovative wall structure that, compared to existing house walls and building structures made of reinforced concrete, has approximately half the weight and is thinner at the same load-bearing capacity.

[0022] The base material (hereinafter "base") consists of a water glass-based fiber-reinforced matrix, for example as described in patent application EP 1062092. Among others, carbon fibers are used that can withstand high tensile loads and shrink when heated, so not only is the thermal expansion coefficient negative, but they also provide a lasting stabilization of the relatively thin stone slabs.

[0023] By using temperature-stable mineral water glass adhesive, for example, in combination with carbon fibers having a negative coefficient of thermal expansion, such high-reliability stabilization can even be applied to very large stone slabs. In addition, it is also possible to meet the optimization requirements for the mechanical and thermal load-bearing capacity of thin stone structures in such a way that the overall coefficient of thermal expansion of the slabs is controlled over a wide temperature range in order to prevent warping of the entire slab while still achieving a lightweight structure. In order to transfer the compressive forces that such a house wall must withstand into the wall, the reinforcing ribs described in the present invention are bonded to the stone slabs with a mineral adhesive. Such a bond can be improved by means of a through dovetail connection. For fire protection reasons, a particularly advantageous material for this structure is wood, which is used, for example, for the internal or even external reinforcing ribs that prevent the wall from buckling. Wood has reliable fire resistance in this structure and can even withstand extreme temperatures in the absence of air. For the external reinforcing ribs, the combination of the external reinforcing ribs with the stone slabs is achieved by means of dovetail connection technology, and the reinforcing ribs are connected to each other in a way that is resistant to high temperatures, thus preventing the stone slabs from buckling in the event of a fire. The overall design of the innovative wall structure described here takes into account the fact that the stone has not only a sufficiently high water resistance but also a porosity that allows the necessary water uptake, so that a special moisture barrier is not necessary. Over a longer timescale, the stone slabs have the ability to absorb a certain amount of water, allow a certain amount of water to pass through and release a certain amount of water, thus enabling the regulation of the internal and external humidity balance. At the same time, the biochar is able to assist in this respect by virtue of its water absorption and release capacity.

[0024] In addition, if the carbon content of the insulation in such a wall design is high, such carbon can not only improve the insulation properties and the humidity regulation and reduce the expansion coefficient and the weight of the insulation, but also, due to the relatively large volume of the insulation compared to the support structure, make the structure a large carbon sink. In this way, by using a building material that adapts to climate change, the climate goals can be achieved. This new building material concept is intended to reverse the emissions of the previous building materials that led to carbon dioxide emissions and to contribute to the capture and storage of carbon dioxide.

[0025] In the present invention, the load-bearing stone layer or mineral material layer plays a crucial role as an additional carbon dioxide sink. Certain types of rock or mineral dust generated during the cutting of slabs have a high potential for causing weathering. When exposed to water and carbon dioxide, such dust carbonates, thus enabling the carbon from the atmosphere in the form of carbon dioxide to enter the mineral structure and to be permanently bound therein. This process is known in the field of climate science as enhanced rock weathering (ERW). If such dust were to be applied to the natural world or to farmland, it would represent a virtually inexhaustible and scalable carbon dioxide sink. Stone dust is a by-product of the manufacturing process for house walls, and because the particle size and surface area of the stone dust generated during the cutting of slabs generally correspond to the values that can be successfully calculated in climate models, it does not need to be ground using renewable energy, as climate scientists originally envisaged, before use. ERW has thus become an independently sustainable business model that is growing rapidly in the construction sector. Since the overall cost-benefit ratio of the structure is not substantially different from buildings using steel and reinforced concrete, and since the manufacturing process requires less energy and does not fundamentally involve a carbon dioxide-emitting process like cement production, it is generally an extremely cost-effective example of a measure to combat climate change. The weathering rate of feldspar or basalt is 450 g of carbon dioxide per kg of rock dust.

[0026] In addition, the manufacture of such house walls has highly negative carbon dioxide emission characteristics due to the carbon dioxide sequestration of the biochar and the rock dust. Calculations have shown that the carbon dioxide sequestration of the biochar and the rock dust is roughly equivalent. In addition, carbon fibers can further contribute to the negative carbon dioxide emission characteristics if they are permanently stored underground after use instead of being incinerated.

[0027] Since the insulation layer is relatively loose, the load-bearing stone slabs must be supported in order to prevent them from breaking due to too great a buckling force. This can be achieved by installing support ribs that are firmly connected to the stone slabs in the longitudinal direction. Such support ribs do not intersect the middle of the wall in order to prevent the formation of thermal bridges. In addition, a force-fitting connection is formed at least in the middle using a material with low thermal conductivity in order to ensure that the stone slabs are sufficiently resistant to buckling forces even if they lose their compressive strength due to high temperatures in the event of a fire. Since such a material must have as high a temperature resistance as possible in addition to low thermal conductivity, wood, glass or ceramic is used as a reasonable compromise. Such elements should not be connected to the opposite reinforcing ribs by means of an adhesive bond, but rather, in line with common practice for wooden structures, by a purely mechanical force-fitting structural connection, for example by dovetail joints.

[0028] As one of the various embodiments, Fig. 1 shows a cross section of a wall. As shown, the wall has two stone slabs (1) stabilized on the outside by a carbon layer (2) containing a vitreous matrix. Between the two stone slabs coated with fibers, an insulation layer (3) is inserted, which consists of a loose filling of carbon dioxide-based coal with a high carbon content. Figs. 2, 3 and 4 show a longitudinal section of the wall at the location of the reinforcing ribs (5) which have a sufficiently high compressive and tensile strength. Such reinforcing ribs are attached to the inside of the stone slabs and are bonded to the stone slabs on one side by a mineral adhesive. Load transfer points (4) at the top and at the bottom on both sides serve to transfer compressive forces into the wall or out of the wall. Figs. 2 and 3 show the location of the reinforcing ribs in combination with dovetail joints. Fig. 4 shows the location of the wall without dovetail joints but with internal and external reinforcing ribs. As shown in Fig. 3, the reinforcing ribs are connected to each other by dovetail-shaped wedges (6) in order to absorb the impact forces as long as possible even in the event of a fire. If necessary, the internal filling of carbon fibers can be mechanically supported by the embedded mineral wool fibers.

[0029] Fig. 5 shows a cross section of the wall at a location without reinforcing ribs. Here, in contrast to Fig. 1, only one of the two stone slabs (1a) is stabilized on the outside by carbon fibers, while the other stone slab (1b) is stabilized on the inside by carbon fibers. Which of the stone slabs has the matrix fiber layer on the inside can depend, for example, on which of the stone slabs is subjected to higher temperatures or for a longer period of time in the event of a fire. For a stone slab, the inside can be coated with carbon fibers if it is likely to be subjected to higher temperatures.

Claims

1. A load-bearing wall unit for a building, comprising two symmetrically arranged support plates made of stone, natural stone, artificial stone, ceramic, concrete, glass, or a glass-containing material, characterized in that: The insulating layer between the two support plates, made of insulating material and with a gradually increasing cross-section, strengthens the entire structure. The support plate is stabilized by a fibrous, heat-resistant matrix. The load-bearing wall unit has load-introducing structures at the top and bottom, wherein the load-introducing structures are connected to the support plate by bonding with shear-resistant permanent adhesive, thereby forming a force-fitting connection; The gradually increasing cross-section insulating layer is composed of a loosely packed, carbon dioxide-based material with high porosity; and Each of the two support plates is made of different or similar materials, and the waste from their manufacture has a high weathering rate.

2. The load-bearing wall unit according to claim 1, characterized in that, A stabilizing fiber matrix layer is disposed on the inner and / or outer side of at least one load-bearing slab, and the fiber matrix layer contains carbon fibers.

3. The load-bearing wall unit according to claims 1 and 2, characterized in that, The layer is composed of a carbon-based insulating material derived from atmospheric carbon dioxide.

4. The load-bearing wall unit according to claims 1 to 3, characterized in that, The layer is composed of pure biochar.

5. The load-bearing wall unit according to claims 1 to 4, characterized in that, The carbon fibers are derived from atmospheric carbon dioxide and obtained from bio-based glycerol or bio-based lignin.

6. The load-bearing wall unit according to claims 1 to 5, characterized in that, The carbon-based insulating material layer is mechanically supported by rock wool.

7. The load-bearing wall unit according to claims 1 to 6, characterized in that, Each of the support plates has its own reinforcing rib or multiple reinforcing ribs arranged at specific intervals on its inner or outer side by means of a heat-resistant mineral adhesive.

8. The load-bearing wall unit according to claims 1 to 7, characterized in that, The mineral adhesive is based on water glass.

9. The load-bearing wall unit according to claims 1 to 8, characterized in that, The support plates are connected to each other in a force-transmitting manner, such that one or all of the reinforcing ribs are located inside the structure.

10. The load-bearing wall unit according to claims 1 to 9, characterized in that, The force-applying connection between the reinforcing rib and the load-bearing plate is achieved through a dovetail tenon.

11. The load-bearing wall unit according to claims 1 to 10, characterized in that, The force-fitting connection between the reinforcing ribs is achieved through dovetail joints made of wood, glass, or porcelain.

12. The load-bearing wall unit according to claims 1 to 11, characterized in that, The entire structure has a negative carbon dioxide footprint, for example, it is a negative carbon dioxide emission structure and therefore a carbon sink.

13. The load-bearing wall unit according to claims 1 to 12, characterized in that, At least one load-bearing slab is composed of gabbro and / or basalt.

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