Building material or binder, and method for the production thereof and use of a shale additive as a component of a building material or binder

Abstract

According to the invention, a binder or a building material comprises at least one fiber and a shale additive.

Description

[0001]Building material or binder and method for its production as well as use of a fiber and a slate additive as a component of a building material or binder. Technical field The invention relates to a binder or a building material comprising at least one fiber and a slate additive. The invention further relates to a method for producing a building material or a binder and to the use of a fiber and a slate additive as a component of a building material or a binder. State of the art Binders and building materials such as concrete are known from the prior art. However, the mechanical strength, resistance to harmful influences and environmental compatibility of such building materials and binders are often problematic, usually with regard to some of the components used in the prior art.Object of the invention The object of the present invention is to overcome the disadvantages of the prior art. Solution to the problem The subject matters of the independent claims lead to the solution of the problem. Advantageous embodiments are described in the dependent claims. According to a first embodiment, the present invention relates to a binder comprising at least one fiber and a slate additive. In the context of the present invention, the at least one fiber preferably refers to a group, type or variety of fibers, and not, for example, an individual staple fiber which is often only visible under a microscope, nor, for example, an individual filament. It is conceivable to use one or more types, varieties or groups of fibers. The binder can be, for example, cement or a cement-like mixture, lime or pozzolan.The binder can therefore be selected from the group consisting of cement, lime, and pozzolans. In the context of the present invention, pozzolans are preferably understood to mean artificial or natural rocks which contain, for example, silicon dioxide, clay, limestone, iron oxide, or alkaline substances, and which are preferably capable of binding in conjunction with calcium hydroxide and water. According to a second exemplary embodiment, the present invention relates to a building material comprising at least one binder and a slate additive, as well as at least one fiber. The building material can be selected from a group consisting of concrete, mortar, and plaster. The binder contained in the building material can be selected from the group consisting of cement, lime, and pozzolans. With regard to the binder, the above statements regarding the binder according to the first exemplary embodiment of the present invention apply.For example, concrete containing cement as a binding agent can be considered. Furthermore, concrete containing lime and / or other pozzolans as a binding agent can be considered. Furthermore, mortar containing cement as a binding agent can be considered. Furthermore, mortar containing lime and / or other pozzolans as a binding agent can be considered. The same applies to plaster as a building material. In addition to the binding agent, the slate additive and the fiber, the building material can contain an aggregate. Alternatively, the slate additive can be used as an aggregate and be contained as the only such aggregate in the building material. If the building material contains an aggregate in addition to the slate additive, this can be a filler, for example an aggregate. The building material according to the first exemplary embodiment and the binder according to the second exemplary embodiment can contain at least one fiber, iea type, group or variety of fibers, which can be selected from the group of organic natural fibers, inorganic natural fibers, chemical fibers, regenerated fibers and wood fibers. Organic natural fibers can be of animal or plant origin. Organic natural fibers of animal origin can be, for example, wool, fine animal hair, coarse animal hair or silk. Examples of suitable wool include sheep's wool, angora, cashmere and the like. Examples of suitable coarse animal hair include horsehair or pig bristles. Examples of suitable silk include mulberry silk or spider silk. Organic natural fibers of plant origin can be, for example, seed fibers, bast fibers and hard fibers. Examples of suitable seed fibers include cotton or plant silk. Examples of suitable bast fibers include, for example, bamboo fibers, hemp fibers, nettle fibers and linen, i.e. flax fibers.Furthermore, fibers from reeds, straw or hay can be considered. According to one embodiment of the present invention, plant fibers, i.e. organic natural fibers of plant origin, are particularly preferred. The plant fibers hemp fibers, linen and stinging nettle fibers are particularly preferred. The fibers can therefore particularly preferably be selected from the group of hemp fibers, linen and nettle fibers. The aforementioned fibers, which are added to the binder or building material, increase its strength, durability and load-bearing capacity in a similar way to what would be the case with the addition of steel fibers. However, the aforementioned fibers, in particular the organic natural fibers and especially the plant fibers, are significantly more environmentally friendly than steel fibers and cheaper to manufacture and also to dispose of a component made with the binder or from the building material.The building material or binder can contain the slate additive in the form of chippings, sand, gravel, or flour in the building material or binder. Slate in the form of chippings, which is added to the building material or binder as an additive, is understood within the scope of the present invention to preferably mean bulk material made of stones with a diameter between 2 and 63 millimeters (mm). In contrast to gravel, which consists of round pebbles, chippings usually consist of rather sharp-edged rubble. Slate can also be used as an additive in the form of sand, gravel, or flour. Within the scope of the present invention, sand preferably means bulk material made of rock with a grain size of 0.063 mm to 2 mm. Gravel preferably means rock with a grain size between 32 and 63 mm. Flour preferably means rock with a grain size of less than 0.063 mm.The slate additive can be predominantly or entirely in the form of unexpanded slate. Expanded slate is a porous and therefore lightweight aggregate that is industrially produced in an expansion process at approximately 1,200°C. Within the context of the present invention, a slate additive predominantly in the form of unexpanded slate means slate in the form of a bulk material that preferably consists of more than 50%, more preferably more than 70%, and even more preferably more than 90% unexpanded slate. A slate additive entirely in the form of unexpanded slate means a bulk material that contains no expanded slate. A slate additive consisting predominantly or entirely of unexpanded slate has proven advantageous. Unexpanded slate, in particular, has a reducing effect, i.e., acts as an electron donor.This can have a positive effect on the setting process of concrete, for example, where chemical processes such as hydration are positively influenced at the interface between cement and water. The slate additive, particularly the unexpanded part of the slate, also has a positive effect after the building material has set. For example, the building material, e.g. concrete, is more water-repellent, acid-resistant, frost-resistant, less reactive with regard to nitrogen compounds, more mechanically stable, and less prone to mold and germ growth as well as to sulfur formation during aging than would be the case without the slate additive. The slate additive also improves the surface density. The reducing property of the slate additive, which can persist even after setting, also creates anti-oxidative properties in the component made from the building material, for example a concrete wall or the like.On the one hand, this results in, for example, the previously described reduced tendency to microbial contamination. On the other hand, this anti-oxidative, i.e., reducing, property of the slate additive also has a positive effect when the component in question is reinforced concrete, since the steel is more corrosion-resistant thanks to the slate additive. Furthermore, the reducing property of the slate additive, especially when it is sand, flour, or chippings from unexpanded slate, provides beneficial preservation of the added fibers, for example, organic natural fibers such as plant fibers. Furthermore, the slate additive protects the aforementioned fibers from moisture.In addition to the aforementioned advantages of the slate additive, it also preserves the fibers, extending the durability of a component made from the binder or building material, and preserving the fibers' beneficial properties for longer, even under adverse conditions. Before adding the fibers to the binder or building material, bacteria can optionally be applied to the fibers. This can be bacteria capable of biomineralization. In general, mineral-forming bacteria, especially calcifying bacteria, are considered. For example, bacteria of the species Sporosarcina pasteurii, Bacillus cohnii, or Bacillus pseudofirmus can be used.The purpose of applying the bacteria to the fibers can, on the one hand, be to provide the bacteria with a suitable carrier with which they can be incorporated into the building material or binder as a component of the building material or binder. On the other hand, the fibers can serve as starting materials for the bacteria's metabolic processes. On the one hand, the bacteria can feed on the fibers or reproduce with the help of the fibers and on the fibers. On the other hand, the fibers can provide starting materials for metabolic processes of the bacteria which can be understood as biomineralization, i.e. in which mineral products are formed. These mineral products, for example phosphates or carbonates, can be formed by the bacteria from corresponding sources, i.e. starting materials containing a phosphorus or calcium source.These mineral products can fill and repair cracks or defects that form, for example, during or after the setting of concrete, i.e. during or after its drying and hardening. It is also possible that at least some of the bacteria in the building material, for example in the concrete, survive or at least are preserved to such an extent that at least the metabolic processes that enable biomineralization are maintained for a long time, i.e. for years or even decades. The bacteria can remain dormant and inactive for years or even decades. If cracks or similar defects occur in the building material, for example in the concrete, the bacteria can become active and carry out the desired biomineralization by means of corresponding metabolic processes.For example, bacteria of the species Sporosarcina pasteurii, Bacillus cohnii, and Bacillus pseudofirmus are capable of remaining dormant and inactive for decades, becoming active only upon contact with air and moisture, i.e., when cracks or defects appear in a building material such as concrete. The fibers to which the bacteria are applied serve as carriers and suppliers of the starting materials for bacterial metabolic processes—in other words, as carriers and nutrients. Building materials such as concrete, into which bacteria have been introduced with the aforementioned ability to repair any cracks that may occur, are sometimes referred to as self-healing building materials, e.g., self-healing concrete.The fibers used according to the invention, particularly plant fibers, are inexpensive and easy to handle, and the application of the bacteria and the incorporation of the bacteria-infused fibers into the binder or into the building material is simple and cost-effective. If cracks or the like form in a component made from the building material, for example, a concrete component, due to prolonged or intensive exposure to harmful influences such as frost, chemicals, acids, oxidative agents, or mechanical stress, the slate additive can provide an alkaline environment, which is preferred by some of the bacteria capable of biomineralization.According to one embodiment of the present invention, the building material, for example, concrete, mortar, or plaster, can consist of the following components: an organic natural fiber, preferably selected from the group consisting of hemp fibers, linen, and nettle fibers; a binder selected from the group consisting of cement, lime, and pozzolan; a slate additive in the form of chippings, sand, gravel, or flour, which is predominantly or entirely in the form of unexpanded slate; and at least one aggregate. According to this embodiment, the building material contains no steel, no steel fibers, no bactericides, and no toxic additives such as setting accelerators or water repellents.In addition to the above-described binder and the above-described building material, the present invention further comprises, according to one exemplary embodiment, a method for producing a building material or a binder, comprising the following steps: - adding a fiber - adding a slate additive. With regard to details on the binder, the building material, the fibers, and the slate additive with regard to the above-described method, reference is made to the statements regarding the building material and the binder according to the exemplary embodiments described above. As described above with regard to the building material and the binder, bacteria can also be applied to the fiber according to the present method. The bacteria are preferably applied to the fiber before the fiber is mixed with other components of the building material or the binder.If bacteria are to be used, the fiber can be suspended in a bacterial suspension, mixed with it, sprayed, soaked in it, or sprinkled with it. Other variants for applying the bacteria to the fiber are conceivable. It could also be considered to incubate the fiber before adding it to the building material or binder in order to multiply the bacteria. The fiber can therefore be inoculated with the bacteria. The incubation can take place over a period of several hours or days. This can involve an evolutionary selection process of the bacteria before they are added to the building material or binder, so that after the building material, e.g. concrete, has hardened and dried, those bacteria are present in large numbers on the fibers which feel most at home on the selected fibers in terms of their properties as carriers and suppliers of starting materials for bacterial metabolism.A building material or binder produced in this way is particularly durable and therefore particularly sustainable. This durability alone significantly increases the sustainability of the building material or binder. Furthermore, the use of fibers, particularly when plant fibers or other fibers of natural origin are used, eliminates the need for toxic, environmentally harmful, and, for example, persistent additives, which in the prior art provided the increased resilience that can be provided by the fibers according to the invention. Of course, only one type or multiple types of bacteria can optionally be used for the building material according to the invention, the binder according to the invention, and the process according to the invention. The present invention further encompasses the use of a fiber and a slate additive as components of a building material or binder.Here, the fiber and the slate additive are used in combination. For details on the building materials or binders, the fiber and the slate additive, please refer to the binders and building materials described above in the described examples.

Claims

Patent claims 1. Binder comprising at least one fiber and a slate additive.

2. Binder according to claim 1, which is selected from the group consisting of cement, lime and pozzolans.

3. Building material comprising at least a binder and a slate additive as well as at least one fiber.

4. Building material according to claim 3, comprising at least one aggregate.

5. Building material according to one of claims 3 or 4, which is selected from the group consisting of concrete, mortar and plaster.

6. Building material according to one of claims 3 to 5, wherein the binder is selected from the group consisting of cement, lime and pozzolans.

7. Building material or binder according to any of the preceding claims, wherein the fiber is selected from the group consisting of organic natural fiber, inorganic natural fiber, chemical fiber, regenerated fiber, and wood fiber.

8. Building material or binder according to any of the preceding claims, wherein the slate additive is contained in the building material or binder in the form of chippings, sand, gravel or flour.

9. Building material or binder according to any of the preceding claims, wherein the slate additive is predominantly or entirely in the form of unexpanded slate.

10. A method for producing a building material or a binder comprising the following steps: - Addition of a fiber - Addition of a slate additive.

11. Use of a fiber and a slate additive as a component of a building material or binder.