Building material or binder, and method for the production thereof and use of a fiber 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 to which bacteria have been applied prior to the addition of the fiber to the binder or the building material.

Description

[0001] Building material or binder and process for its production as well as use of a fiber as a component of a building material or binder

[0002] Technical area

[0003] The invention relates to a binder or a building material comprising at least one fiber to which bacteria have been applied prior to its addition to the binder or the building material. The invention further relates to a method for producing a building material or a binder, as well as to the use of a fiber to which bacteria have been applied as a component of a building material or a binder.

[0004] State of the art

[0005] Binding agents and building materials such as concrete, to which bacteria are added to repair any cracks or similar problems, are well known. Introducing the bacteria into the building material is often complex and expensive, as is producing suitable carrier materials for the bacteria.

[0006] Object of the invention The object of the present invention is to overcome the disadvantages of the prior art.

[0007] Solution to the task

[0008] The subject matter of the independent claims leads to the solution of the problem. Advantageous embodiments are described in the dependent claims.

[0009] According to a first embodiment, the present invention relates to a binder comprising at least one fiber to which bacteria were applied prior to its addition to the binder. Within the scope of the present invention, the at least one fiber preferably refers to a group, type, or variety of fibers, and not, for example, a single staple fiber, often only visible under a microscope, nor, for example, a single filament.

[0010] The binding agent can be, for example, cement or a cement-like mixture, lime, or pozzolan. The binding agent can therefore be selected from the group consisting of cement, lime, and pozzolans. For the purposes of the present invention, pozzolans are preferably understood to mean artificial or natural rocks containing, for example, silicon dioxide, clay, limestone, iron oxide, or alkaline substances, and are preferably capable of binding in combination with calcium hydroxide and water.

[0011] According to a second embodiment, the present invention relates to a building material comprising at least one binder and at least one aggregate, as well as at least one fiber to which bacteria were applied prior to their addition to the building material. The building material can be selected from a group comprising concrete, mortar, and plaster.

[0012] The binder contained in the building material can be selected from the group consisting of cement, lime, and pozzolan. Regarding the binder, the above statements regarding the binder according to the first embodiment of the present invention apply.

[0013] For example, it could be intended for concrete containing cement as a binding agent. It could also be intended for concrete containing lime and / or other pozzolans as a binding agent.

[0014] Furthermore, mortar containing cement as a binding agent may be considered. Furthermore, mortar containing lime and / or other pozzolans as a binding agent may be considered.

[0015] The same applies to the building material plaster.

[0016] The aggregate can be a filler, for example an aggregate.

[0017] The building material according to the first embodiment and the binder according to the second embodiment contain at least one fiber, i.e., a type, group, or grade of fiber, 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.

[0018] Organic natural fibers of animal origin can include wool, fine animal hair, coarse animal hair, or silk. Examples of wool include sheep's wool, angora, cashmere, and the like. Examples of coarse animal hair include horsehair or pig bristles. Examples of silk include mulberry silk or spider silk.

[0019] Organic natural fibers of plant origin can be considered, 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 bamboo fibers, hemp fibers, nettle fibers, and linen, i.e., flax fibers. Fibers from reeds, straw, or hay can also be considered. According to one embodiment of the present invention, plant fibers, i.e., organic natural fibers of plant origin, are particularly preferred.

[0020] Particularly preferred plant fibers are hemp fibers, linen, and nettle fibers. The fiber can therefore particularly preferably be selected from the group consisting of hemp fibers, linen, and nettle fibers.

[0021] The bacteria used in the building material according to the first embodiment and in the binder according to the second embodiment can be capable of biomineralization. In general, therefore, mineral-forming bacteria, especially calcifying bacteria, can be considered. For example, bacteria of the species Sporosarcina pasteurii, Bacillus cohnii, or Bacillus pseudofirmus can be used.

[0022] The fibers improve the properties of the building material or binder, for example, by increasing its strength, durability, and resilience in a similar way to what would be achieved with the addition of steel fibers. However, the aforementioned fibers, especially organic natural fibers and especially plant fibers, are significantly more environmentally friendly and cheaper to manufacture than steel fibers, as well as to dispose of a component made with the binder or from the building material. Applying the bacteria to the fibers can, on the one hand, 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.

[0023] On the other hand, the fibers can serve as starting materials for bacterial 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 that can be considered biomineralization, i.e., in which mineral products are formed.

[0024] 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 thus repair cracks or defects which 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 which 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.When cracks or similar defects appear in the building material, for example in concrete, the bacteria can become active and carry out the desired biomineralization through corresponding metabolic processes. For example, bacteria of the species Sporosarcina pasteurii, the species Bacillus cohnii, and the species Bacillus pseudofirmus are capable of remaining dormant and inactive for decades, only becoming active upon contact with air and moisture, i.e., when cracks or defects appear, for example, in a component made of the building material such as concrete. The fibers to which the bacteria were applied according to the invention serve as carriers and as suppliers of the starting materials for the bacterial metabolic processes—in other words, as a habitat and food, so to speak.

[0025] 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.

[0026] The fibers used according to the invention, in particular plant fibers, are inexpensive, easy to handle and the application of the bacteria and the introduction of the fibers mixed with bacteria into the binder or into the building material, as described in more detail below, is simple and cost-effective.

[0027] Slate can be added as an additive to the binder or building material according to the embodiments described above. The slate additive can preferably be used in the form of chippings, gravel, sand, or flour.

[0028] If a component made from the building material, for example, a concrete component such as a wall or the like, is still essentially intact, the slate additive ensures that the fibers are preserved and protected from moisture. According to embodiments of the present invention, a concrete component produced in this way is less susceptible to harmful influences such as oxidative agents, water, acids, frost, and even mechanical stress. If, for example, cracks or the like form due to prolonged or intensive exposure to such or other harmful influences, 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, which is 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; at least one aggregate; wherein, prior to its addition to the building material, bacteria capable of biomineralization, in particular bacteria of the species Sporosarcina pasteurii, Bacillus cohnii, or Bacillus pseudofirmus, were applied to the fiber. 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.

[0029] In addition to the above-described binder and the above-described building material, the present invention further comprises, according to one embodiment, a method for producing a building material or a binder comprising the following steps:

[0030] - Applying bacteria to a fiber

[0031] - Mixing the fiber with at least one other component of the binder or building material.

[0032] With regard to details on the binder, the building material, the fibers and the bacteria with regard to the aforementioned method, reference is made to the explanations regarding the building material and the binder according to the embodiments described above.

[0033] The bacteria are preferably applied to the fiber before mixing the fiber with other components of the building material or binder. For example, 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.

[0034] It may also be considered to incubate the fiber before adding it to the building material or binder to promote bacterial growth. The fiber can then be inoculated with bacteria. This incubation can take place over several hours or days. An evolutionary selection process of the bacteria can take place before they are added to the building material or binder, so that after the building material, such as concrete, has hardened and dried, the bacteria that are most at home on the selected fibers, given their ability to act as carriers and suppliers of starting materials for bacterial metabolism, are present in large numbers on the fibers.

[0035] 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, especially 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 load-bearing capacity that can be provided by the fibers according to the invention.

[0036] Of course, one or more types of bacteria can be used for the inventive building material, the inventive binder, and the inventive method. Furthermore, one or more types, varieties, or groups of fibers can be used.

[0037] The present invention further encompasses the use of a fiber to which bacteria have been applied as a component of a building material or binder. For details regarding the building materials or binders, the fiber, and the bacteria, reference is made to the binders and building materials described above according to the described embodiments.

Claims

Patent claims 1. Binder comprising at least one fiber onto which bacteria were applied prior to its addition to the binder.

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

3. Building material comprising at least one binder and at least one aggregate as well as at least one fiber onto which bacteria were applied before being added to the building material.

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

5. Building material according to one of claims 3 or 4, wherein the binder is selected from the group consisting of cement, lime and pozzolans.

6. 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.

7. Building material or binder according to any of the preceding claims, wherein the bacteria are capable of biomineralization.

8. Building material or binder according to any of the preceding claims, to which a slate additive has been added.

9. A process for the manufacture of a building material or a binder comprising the following steps: - Applying bacteria to a fiber - Mixing the fiber with at least one other component of the binder or building material.

10. Use of a fiber onto which bacteria have been applied as a component of a building material or a binder.