EP4251384A1

EP4251384A1 - 3d printing method for producing an article consisting of concrete or mortar and having an opening

Info

Publication number: EP4251384A1
Application number: EP21802348.9A
Authority: EP
Inventors: Muhammed Nasuh ALTIN; Krettek LUKAS; Stefan Staudacher; Tim Guhl
Original assignee: Saint Gobain Weber SA
Current assignee: Saint Gobain Weber SA
Priority date: 2020-11-25
Filing date: 2021-11-03
Publication date: 2023-10-04
Also published as: WO2022111955A1; EP4005759A1; EP4005759C0; EP4005759B1

Abstract

The present invention relates to a method for producing an article (G) that consists of concrete or mortar, by way of 3D printing: wherein (A) strands (2) of a concrete or mortar mass (1) are applied layer by layer on top of one another by means of an industry robot, thereby producing a raw article (G'), and (B) a region (B) of the raw article (G') is removed by a separating manufacturing method so that an opening (B') is produced.

Description

3D printing process to create a concrete or mortar object with a bushing

The invention relates to a method for producing an object made of concrete or mortar by means of 3D printing, and an object produced in this way.

The 3D printing of objects made of concrete or mortar is known per se. In this case, a concrete or mortar mass is applied in layers on top of one another in the form of webs, corresponding to the shape of the object to be produced. From the raw object to be produced with the desired shape, the object is created by hardening the concrete or mortar mass. By way of example only, reference is made to EP1587995A2, US2015072068A1, EP3260258A1 and EP3284879A1.

3D printing can be used to produce objects made of concrete or mortar with a high level of design flexibility. However, the 3D printing process reaches its limits when objects with penetrations are to be produced, such as those found in concrete walls with window or door openings or penetrations for cable ducts, drain pipes, water pipes or similar. No tracks of concrete or mortar mass can be deposited above such a passage, because these require stabilization in the not yet hardened state. Stabilization is ensured by the underlying tracks, which are not present in the case of the implementation. When 3D printing plastic objects, it is common in such cases to print a pillar or mesh-like support structure, which is not possible when 3D printing objects made of concrete or mortar, since such comparatively delicate structures are not feasible.

A method for 3D printing of concrete objects is known from US20140308381 A1, the print head being equipped with a cutting tool. This means that the concrete mass is divided up in strips immediately after it has been separated. This creates a cutout comprising multiple tracks that can be removed after curing to create a feedthrough.

CN106088610A discloses a 3D printing method for manufacturing a concrete wall with a penetration. At the location of the leadthrough to be created, a temporary support structure is printed, as it were, which consists of an easily removable material, in particular of foamed plastic or a concrete mass with delayed hardening. After the rest of the wall has hardened, the support structure is removed with a tool that is not described in detail.

FR3047258A1 discloses a 3D printing method for producing a concrete wall with a penetration. A water-soluble temporary support structure is printed at the location of the lead-through to be created, which is removed after the rest of the wall has hardened.

There is a need for improved methods for 3D printing objects made of concrete or mortar that allow more flexible design. In particular, it should be possible to produce objects with leadthroughs, preferably with any shape. The object of the present invention is to provide such a method.

The object of the invention is achieved according to the invention by a method according to independent claim 1. Preferred embodiments are evident from the dependent claims.

The method according to the invention for producing an object from concrete or mortar by means of 3D printing comprises the production of a raw object by means of conventional 3D printing. In this case, webs of a concrete or mortar mass are applied in layers on top of one another, as a result of which a raw object is produced. At least a portion of the raw object is then removed.

By subsequently removing material after the actual 3D printing, almost any shape of the object can be realized. In particular, leadthroughs can be created if the material is not removed from the at least one area until the concrete or mortar mass has hardened to such an extent that the area above the leadthrough no longer requires mechanical support. These are great advantages of the present invention.

The concrete or grout is typically applied by a printhead that includes a nozzle. The concrete or mortar mass is fed to this nozzle by means of a pump via a supply line. The concrete or mortar mass contains at least one aggregate, a binder and added water. The aggregate can be of natural or synthetic origin. Cement or lime is preferably used as the binder. The concrete or mortar mass can optionally contain concrete additives and/or concrete additives. The concrete or mortar mass is free-flowing and can therefore be separated by the print head. After the separation, the concrete or mortar mass begins to harden, losing its fluidity as a result of chemical processes (in particular the storage of the added water as crystal water: hydration) and evaporation of the added water. The cement paste is converted into cement stone. The hardening comprises in particular first the stiffening, then the hardening and then again the hardening of the concrete or mortar mass. The setting represents the first phase of the hydration, whereby the concrete or mortar mass can still be processed. During the subsequent solidification (setting) phase, there is a significant increase in viscosity. During the final phase of hardening, hydration is completed.

Complete hardening can take several months. It is not necessary to wait for the entire hardening phase if the raw object is to be processed further when it is no longer flowable, in particular by removing the at least one region of the raw object. Curing in the context of the invention therefore includes in particular the phases of stiffening and solidification, so that the raw object has lost its flowability and has sufficient stability, with no undesirable plastic deformation of the concrete or mortar mass, for example under the influence of gravity, more occurs .

Concrete additives are powdered or liquid additives that affect certain properties of the concrete or mortar mass. Concrete additives can be mineral fines (e.g. ground rock, fly ash, tuff, trass and/or silica dust), organic substances (e.g. synthetic resin dispersions, in particular to improve workability and adhesion), color pigments and/or fibers (in particular steel, glass or plastic fibres) be used. Concrete admixtures are substances dissolved or slurried in water that are added to the concrete or mortar mass in order to change their properties, such as workability, setting behavior, hardening or durability, through physical and/or chemical effects. Examples of concrete additives that can be used are plasticizers, superplasticizers, stabilizers, Air entraining agent, setting accelerator, hardening accelerator,

Setting retardants, hardening retardants and/or sealants are used. The proportion of concrete additives is preferably less than 4% by weight of the concrete or mortar mass, particularly preferably at most 4% by weight, for example from 0.2% by weight to 2% by weight.

The nozzle can be designed as a simple tube with a constant cross-section in the flow direction of the concrete or mortar mass, or it can also have a narrowing or widening cross-section. The outlet opening of the nozzle can be of any shape in order to achieve an outlet cross section that is suitable for the specific application. The shape of the nozzle, in particular its outlet opening, is preferably adapted to the width and thickness of the sheet of concrete or mortar mass to be produced. The concrete or mortar mass is fed to the nozzle via a feed line, which in particular includes pipes and/or hose lines.

During the deposition of a web of concrete or mortar mass, the print head is moved in a direction which, within the meaning of the invention, is referred to as the direction of movement of the print head or direction of deposition. A web is a coherent layer of concrete or mortar mass created by moving the push button along the direction of travel. The track can be straight or have any other shape. The web can also form a closed shape by bringing its end back to the beginning. For the purposes of the invention, the dimension of a web in the separation direction is referred to as the length of the web. The perpendicular dimension in the plane of the web is called the width of the web. After a track is created, the next track is deposited as a layer on top of that track. The direction in which the webs are deposited in layers one above the other is referred to as the direction of growth for the purposes of the invention. The raw object is thus built up in layers by 3D printing in the direction of growth "from bottom to top". The dimension of a web in the direction of growth (perpendicular to the length and width) is referred to as the thickness of the web for the purposes of the invention. The summed thickness of the tracks gives the height of the object.

The width and thickness of the webs can be adjusted in particular by the design of the nozzle, the consistency of the concrete or mortar mass and the delivery rate of the concrete or mortar mass. The thickness and the width of all tracks are preferably the same and constant. This is advantageous with regard to a quick and technically simple deposition, because the tracks can then be generated by a uniform movement of the print head without having to make adjustments to the conveying speed or nozzle shape during the process. The length of all tracks can be constant, so that all tracks are aligned at their beginning and their end. In this way, a raw object with a constant dimension is produced. However, it is also possible without any problems for a web to have a shorter length than the web underneath, so that the web underneath is not completely covered with the web. In this way, a raw object can be produced that tapers from bottom to top, either as a whole or in sections. The length, width and thickness of the webs can be freely selected by a person skilled in the art according to the requirements of the application. The width is, for example, from 10 mm to 500 mm, in particular from 20 mm to 100 mm, the thickness, for example, from 5 mm to 100 mm, in particular from 10 mm to 50 mm, which can be produced without any problems using typical nozzles. The maximum achievable height of the object depends on the construction of the robot and the print bed (printing base). The maximum achievable height can be increased, for example, by storing the print bed so that it can move vertically and moving it down during printing.

In an advantageous embodiment, the webs are applied with alternating deposition directions, so that successive webs are deposited with opposite directions of movement of the print head. The beginning of a track thus coincides with the end of the track below. This is advantageous in terms of time-saving construction of the raw article, because the push button does not have to be moved back from the end of the track to the start before the next track is deposited. When passing from one track to the track above it, the discharge of the concrete or mortar mass from the nozzle can be interrupted so that the tracks are separated from each other. Alternatively, the emergence of the concrete or mortar mass can also be continued, so that adjacent tracks are not separated from one another, but are connected to one another by concrete or mortar mass in the manner of a terminal loop. In principle, it is of course also possible to apply the webs with the same deposition direction. The statements apply to webs that do not form closed shapes and whose beginning and end are therefore spaced apart. If the webs form a closed shape, all webs are preferably applied with the same deposition direction. The webs of concrete or mortar mass are deposited by means of a robot, in particular an industrial robot, which moves the print head. The 3D printing is advantageously carried out automatically with the aid of CAD processing, with the CAD data of the raw object being provided to a processing machine and the processing machine using the CAD data to deposit the webs for producing the raw object. The printhead is most preferably mounted on a robotic arm. However, industrial robots can also be used that have fewer degrees of freedom of movement than a robot arm. The push button is preferably moved with the aid of a computer using the CAD data (computer-aided design). The tracks can thus be deposited with high precision and speed and low labor intensity to create the green article.

After the production of the raw object by 3D printing, a portion of this raw object is removed in the method according to the invention. A continuous passage through the raw object of the webs is thereby created. The leadthrough can pass through the object in such a way that it is surrounded all around by areas of the object. However, the leadthrough can also be directly adjacent to a surface. The passage then forms a kind of incision or notch.

Different subtractive manufacturing methods can be used to remove said area, preferably separating manufacturing methods, for example water jet cutting or laser cutting, particularly preferably metal-cutting manufacturing methods such as milling, drilling, chiselling, filing, planing or grinding, very particularly preferably milling. The processing is preferably automated, with the required tool preferably being moved by means of a (further) robot. The movement preferably takes place with the aid of a computer using CAD data (CNC, Computerized Numerical Control), particularly preferably by CNC milling. Alternatively, manual processing is also possible.

Milling is very particularly preferred because this provides a high level of flexibility with regard to the shape of the leadthrough and the shape of the leadthrough can be designed as desired. The high flexibility associated with milling not only allows the creation of bushings with a constant cross-sectional area, but also stepped or tapered bushings. A step-like passage is understood as meaning a passage whose cross-sectional area (perpendicular to the direction of extension of the passage) changes suddenly (or abruptly) at at least one point in the direction of extension, so that a step is produced. A tapering lead-through is understood to mean a lead-through whose cross-sectional area changes continuously at least in sections in the direction of extent.

The passage can be created in the width dimension of the webs. To do this, a section of at least one web is removed over its entire width. In particular, the section of web is removed completely, that is to say over its entire thickness and over its entire width. Typically, several superimposed sections of several directly superimposed webs form the area to be removed and are removed along their entire width, in particular completely.

Alternatively, the leadthrough can also be produced in the length dimension of the webs. For this purpose, a section of at least one web is removed over its entire length. In particular, the section of web is removed completely, that is to say over its entire thickness and over its entire length. Typically, several superimposed sections of several directly superimposed webs form the area to be removed and are removed along their entire length, in particular completely.

The shape and position of the area to be removed depends on the requirements in each individual case, in particular on the purpose of the bushing created. Penetrations with a rectangular, circular or oval cross section are often required, for example as window or door openings or for the subsequent attachment of cable ducts or pipes. However, bushings with any cross-sections can be implemented.

In a variant of the invention, the area is removed after the complete or partial curing of the raw object by the subtractive manufacturing process, the desired object being machined out of the raw object by material removal. The flowability of the concrete or mortar mass must have decreased to such an extent and its dimensional stability have increased to such an extent that subtractive processing is possible without the raw object then being subjected to undesirable deformations, for example under the influence of gravity. It is not necessary for the solidification (or even hardening) phase to be fully completed. This variant is particularly useful for creating feedthroughs that are not adjacent to the top surface of the raw object, leaving an area of the raw object directly above the feedthrough ("floating structure"). This area is sufficiently stabilized by the hardening of the concrete or mortar mass that it no longer needs support from the area below, which can then be removed without the area above sagging under the influence of gravity.

Terms such as "below" and "above", "above" and "beneath", "upper surface" and the like refer to the direction of growth of the raw article for the purposes of the invention, with a web that was deposited later than another web located above this other track.

It is possible to fully 3D print the raw object, cure it in its entirety (fully or partially) and then remove the area. However, since the 3D printing of the raw object can take several hours depending on its size, it is also possible to remove the area from an already cured section if tracks above it are not yet cured or are even still being printed.

In a further variant of the invention, the area is removed before the raw object is cured. The concrete or mortar mass is then still sufficiently flowable and easy to work with. The separating production methods already described can be used, alternatively simple scraping or lifting, for example using a spatula, a trowel, a shovel or a similar tool. This variant is particularly useful for creating feedthroughs that are adjacent to the top surface of the raw object so that no overlying areas remain. The lack of curing is not a disadvantage in this case, because no floating structures are created that would have to be stabilized.

A combination of the two variants is also conceivable, with the concrete or mortar mass being removed before it hardens in the area to be removed, except for one or more remaining pillars, which support the areas above. the Concrete or mortar mass is then still sufficiently flowable and easy to work with, so that it can be removed by simply scraping off or lifting off, for example using a spatula, trowel, shovel or a similar tool, as an alternative to the separating production methods already described. The pillars are in turn only removed after the concrete or mortar mass has hardened, in particular by separating manufacturing processes such as milling.

In principle, it is also possible for the concrete or mortar mass to be removed in the area to be removed before it hardens, except for one or more remaining pillars that support the areas above, with the pillars remaining permanently in the object, so that it has at least two passages comprises, separated by (each) a support structure.

In a further development of the invention, one of the surfaces of the raw object is shaped by removing concrete or mortar mass, in particular the upper surface. Complete web sections do not have to be removed along their entire width. Instead, free processing of the surface is possible, which does not have to be based on the web boundaries and by means of which arbitrarily shaped surfaces can be generated that are not directly accessible with 3D printing, especially rounded shapes. Machining can take place after hardening by separating manufacturing processes or before hardening. The above statements on the production of the feedthrough and the preferred methods used for this apply accordingly.

In one embodiment of the invention, the permanent area of the object and the area to be removed later are printed out of exactly the same mass of concrete or mortar. The two areas therefore do not differ in their composition.

However, it can be advantageous to take measures during 3D printing that promote the subsequent removal of the area of the raw object. In a further embodiment, when creating the area to be removed later, an additive is added to the concrete or mortar mass which is suitable for providing said area with a reduced hardness. The additive can be, for example, a pore or bubble former which is suitable for forming pores in the concrete or mortar mass and thereby reducing its hardness. Compressed air can also be introduced as an additive, so that air bubbles are trapped in the concrete or mortar mass, which in turn form pores. Other chemicals are also conceivable as additives that are suitable for facilitating the removal of the concrete or mortar mass, in particular for reducing its hardness. Chemicals can also be added to the concrete or mortar mass, which can be washed out after hardening in order to reduce the strength. Water can also be used as an additive, which also causes the strength of the concrete or mortar mass to decrease. When 3D printing the other areas of the raw object, the addition of concrete or mortar mass is not added. The additive is added to the concrete or mortar mass (only) when this is applied to the area that is later to be removed. This embodiment is therefore particularly suitable for producing feedthroughs along the width dimension of the tracks. For this purpose, an additive feed line is preferably connected to the nozzle or to the feed line for the concrete or mortar compound connected to the nozzle, as close as possible to the nozzle. The additive is added to the concrete or mortar mass via the additive supply. The additive supply line is preferably valved to selectively initiate the introduction of additive when the nozzle is about to apply the area to be removed and quickly shut off when the nozzle is outside of said area.

In a further advantageous embodiment, a separating layer is arranged under the bottom web and over the top web of the area to be removed. There is a separating layer between the bottom web of the area to be removed and the web directly below, and another separating layer between the top web of the area to be removed and the web directly above. The area to be removed is thus limited at the top and bottom by a separating layer. The length of the separating layer preferably corresponds at least to the length of the area to be removed, particularly preferably exactly to the length of the area to be removed. The width of the separating layer preferably corresponds at least to the width of the area to be removed. The dimensions "length" and "width" of the area to be removed are used in the same way as the length and width of the tracks. The release layer prevents the formation of a stable bond between the top and bottom webs of the area to be removed and the underlying and overlying areas of the green article during curing. This facilitates subsequent removal of said area. But even if the concrete or mortar mass is to be removed before it hardens, such a separating layer can be helpful. the The separating layer can be designed, for example, as a plastic foil, as a metal foil, as a paper, cardboard or wood layer or as a layer of a soap solution. Sedimentary layers or rocks can also be used as a separating layer.

The invention also includes an object made of concrete or mortar, produced by means of 3D printing according to the method according to the invention.

The invention also includes the use of the object according to the invention made of concrete or mortar as part of the masonry of a building, in particular as a masonry component with a passage, for example as a window or door opening or as a passage for a cable duct or a pipeline.

The invention is explained in more detail below with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way.

Show it:

1 shows a side view of the 3D printing of an object made of concrete or mortar during different phases of the method according to the invention,

2 shows a cross section of a raw object,

3 shows a cross section through an object according to the invention obtained from the raw object according to FIG.

4 shows a cross section through a further object according to the invention,

5 shows a cross section through a further object according to the invention,

6 shows a cross section through a further configuration of the raw object,

7 shows a side view of an embodiment of the print head for 3D printing of the subject invention and

8 shows a flow chart of an embodiment of the method according to the invention.

FIG. 1 shows a side view of the 3D print of a raw object according to the invention, the sections of which have already been produced can be seen in cross section. The raw object is produced by conventional 3D printing, with a concrete or mortar mass 1 being stacked in layers on top of one another in the form of webs 2 . The concrete or mortar mass 1 is applied by means of a print head 3, which is attached, for example, to a robot arm 7 and is moved with the associated robot. The print head 3 contains a nozzle 4 which is designed, for example, as a steel tube with a suitably shaped outlet opening. A supply line 6 is connected to the nozzle 4, via which the concrete or mortar mass 1 is supplied to the nozzle 4 by means of a pump, not shown. The print head 3 is moved with the aid of a computer along the pre-calculated shape of the webs 2 using CAD data, with concrete or mortar mass 1 emerging from the nozzle 4 and forming the webs 2 . The direction of movement R of the print head 3 is indicated by a gray block arrow. The thickness of the webs 2 is 2 cm, for example.

FIG. 1a shows the method during the deposition of the first (bottom) web 2. A further web 2 is then deposited on this (FIG. 1b). the The direction of movement R of the print head 3 is opposite to that of the first web 2 when the second web 2 is being deposited. The method is continued (FIG. 1c), the webs 2 being stacked on top of one another with alternating direction of movement R in the growth direction A (also indicated by a gray block arrow) until the raw article has reached the desired height.

FIG. 2 shows a cross section of the finished raw object G', the production of which is illustrated in FIG. The raw object G′ is intended as a wall for a building, for example, and is then to be provided with a leadthrough, for example for a cable duct. Therefore, the green article G' has a portion B (rectangular in side view, cuboid as a whole) to be removed to form the passage. The area B contains sections of several webs 2 directly one above the other, these sections being arranged flush one above the other. The upper and lower limits of area B therefore run along the interface between adjacent webs 2.

The raw object G' is cured after the 3D printing, the concrete or mortar mass 1 losing its flowability and the raw object G' being stabilized. The area B of the raw object G′ is then removed by a machining process such as milling. This is also done with the help of a computer using a robot (CNC milling).

FIG. 3 shows the finished object G according to the invention. The area B of the raw object G′ from FIG. 2 has been removed, so that the object G now has the desired continuous passage B′.

FIG. 4 shows a further embodiment of the object G according to the invention. This object G also has a passage B′. In addition, a portion B adjacent to the top surface of the raw object G' was removed, thereby forming a rounded top surface which cannot be directly accessed by conventional 3D printing. Here, too, it is possible to first harden the raw object G′ and then to remove the region B by cutting, for example by milling. However, since, in contrast to the lead-through B', no area of the object located above the area B needs to be supported, it is easier to remove the concrete or mortar mass 1 from the area B before it hardens, for example by scraping it off with a spatula. FIG. 5 shows a further embodiment of the object G according to the invention. Here, too, the object G has a passage B′, which has a circular cross-section in contrast to the rectangular cross-section in FIG .

FIG. 6 shows a further development of the raw object from FIG. The separating layers 5 are in the form of plastic films, for example, and prevent the formation of a bond between the webs 2 during curing. They thus facilitate the subsequent removal of area B. The separating layers 5 are placed on a web 2 before the overlying web 2 is printed. FIG. 7 shows a further development of the push button 3 from FIG. Additives can be added to the concrete or mortar mass 1 via the additive supply line 8 . For example, when printing the area B to be removed later, pore formers can be added to reduce the hardness of this area B and thus facilitate its removal. Through the valve 9 the addition of the additive can be started when the print head 3 enters the B area and stopped when it leaves the B area.

FIG. 8 shows an exemplary embodiment of the method according to the invention using a flowchart.

Reference list:

(G) 3D-printed object made of concrete or mortar (G ¹ ) raw object (B) area of raw object to be removed G'

(B') Performance of Item G

(1) Concrete or mortar mass

(2) printed web of concrete or mortar mix 1 (3) printhead

(4) Nozzle

(5) release layer

(6) Lead

(7) robotic arm (8) additive feed line

(9) Additive supply line valve 9

(R) Direction of print head movement 3

(A) Direction of growth of raw object G'

Claims

patent claims

1. A method for producing an object (G) from concrete or mortar by means of 3D printing, wherein:

(A) tracks (2) of a concrete or mortar mass (1) are applied in layers to one another by an industrial robot, whereby a raw object (G ¹ ) is produced,

(B) a region (B) of the raw object (G ¹ ) is removed by a separating manufacturing process, so that a leadthrough (B') is produced.

2. The method according to claim 1, wherein the concrete or mortar mass (1) is applied by means of a pressure head (3) which comprises a nozzle (4) which delivers the concrete or mortar mass (1) by means of a pump via a supply line (6 ) is supplied.

3. The method according to claim 2, wherein the print head (3) is moved in method step (A) by the industrial robot, preferably by means of a robot arm (7).

4. The method according to any one of claims 1 to 3, wherein in method step (B) a section of at least one web (2) is removed over its entire width, preferably superimposed sections of several directly superimposed webs (2).

5. The method according to any one of claims 1 to 3, wherein in method step (B) a section of at least one web (2) is removed over its entire length, preferably superimposed sections of several directly superimposed webs (2).

6. The method according to any one of claims 1 to 5, wherein the region (B) is removed by milling, drilling, chiseling, filing, planing, grinding, laser cutting or water jet cutting.

7. The method according to any one of claims 1 to 6, wherein the region (B) after a complete or partial curing of the raw object (G ¹ ) is removed.

8. The method according to any one of claims 1 to 6, wherein the region (B) is removed prior to curing of the green article (G ¹ ), the passage (B') being produced adjacent to an upper surface of the green article (G ¹ ).

9. The method according to any one of claims 1 to 6, wherein part of the region (B) before curing the raw object (G ¹ ) is removed, leaving at least one support pillar which is removed after full or partial curing by a separating manufacturing process .

10. The method according to any one of claims 1 to 9, wherein the concrete or mortar mass (1) contains at least one aggregate, a binder, preferably cement or lime, and added water, and optionally concrete additives and concrete additives.

11. The method according to any one of claims 1 to 10, wherein the concrete or mortar mass (1) in process step (A) when generating the area (B) to be removed later, an additive is added, which is suitable, the area (B) with to provide a reduced hardness, the additive preferably being a pore or blistering agent, compressed air, water, a hardness reducing chemical or a flushable chemical.

12. The method according to claim 11, wherein the additive is added to the concrete or mortar mass (1) via an additive feed (8) connected to the nozzle (4) or the feed line (6).

13. The method according to any one of claims 1 to 12, wherein between the lowermost web (2) of the area (B) and the underlying web (2) and between the uppermost web (2) of the area (B) and the overlying web (2) a separating layer (5) is arranged in each case, which is preferably in the form of a plastic foil, metal foil, paper, cardboard or wood layer, sediment layer or soap solution.

14. Object (G) made of concrete or mortar, produced by means of 3D printing according to the method according to any one of claims 1 to 13.

15. Use of an object (G) according to claim 14 as part of the masonry of a building, for example as a window or door opening or as a passage for a cable duct or a pipeline.