Apparatus, in particular, composite girders and methods for manufacturing and dismantling this apparatus.

Abstract

The device 1, in particular a composite girder, comprises an outer body 2 having an internal space 4 and a core body 3 arranged in said internal space 4, said core body 3 having or consisting of a fibre composite material, in particular wood, which is capable of swelling in contact with a liquid, and in the operating state, said core body 3 swells with the liquid in the internal space 4 and exerts a pressure generated by said swelling on the outer body 2.

Description

Technical Field

[0001] The present invention relates to a device, particularly to a composite girder and methods for manufacturing and disassembling this device.

Background Art

[0002] Devices or load-bearing members similar to girders are configured to absorb loads and are known in the prior art in variously modified forms of materials. On the one hand, particularly steel girders are used in the construction industry due to their high load-bearing capacity. On the other hand, wooden girders are also used for construction purposes and are particularly environmentally friendly materials for building projects.

[0003] For the reasons mentioned above, it is certainly desirable in many cases to use wood as a material. However, the durability of wood outdoors has been a major challenge in wood technology and the use of wood as an industrial member for decades. Particularly when the support structure part or girder is subjected to static and dynamic loads, wood partially and dramatically loses strength and rigidity over a long period due to abiotic and biological degradation, so its requirements very quickly become limiting factors.

[0004] The use of wood in industrial applications poses engineering and process engineering challenges. Highly anisotropic materials and raw materials require, on the one hand, accurate knowledge about the material when using it, and on the other hand, innovative, efficient, and inexpensive solutions can be achieved using homogeneous isotropic materials such as steel and plastic. Those solutions were certainly industrially feasible in many aspects using wood as a material, but were not competitive from an economic perspective because of their more complex shape and higher burden.

[0005] Furthermore, calculations regarding homogeneous materials such as plastics and metals, for example, can be more easily realized, whereby those materials can be more easily handled. Such calculations have only recently become possible for wood.

[0006] Wood has been widely used in various industrial products and equipment. A further drawback of wood is its relatively low energy absorption capacity during fracture, as it is brittle and easily breaks under tension. When it breaks under tension, a sharp-edged fracture surface is mainly observed, which can increase the risk of injury to people caught in the rupture, for example.

[0007] Conventional techniques have involved chemical and / or physical modification of wood to overcome these shortcomings. Different methods can be used to modify or impregnate the entire or partial cross-section of wood, thereby improving the material's properties. Besides improving durability and compensating for swelling, thermal modification has, for the first time, yielded slight improvements in mechanical properties (rigidity and strength), and a decrease in density and hygroscopicity. However, wood modification leads to mechanical changes, such as increased brittleness, and incurs additional costs.

[0008] Another way to improve the durability of wood is to paint it. However, protection by painting cannot be fully guaranteed. Impregnation with protective agents incurs additional costs and involves the release of substances harmful to the environment. In contrast, plastic coverings have drawbacks in terms of waste disposal and recycling after the structural parts are used.

[0009] While composite materials of wood and metal are certainly known to overcome the shortcomings of wood, they have been used very little until now and are a group of materials that are being studied from an industrial science perspective.

[0010] Steel is known to have a high elastic limit, meaning that, unlike wood, it clearly possesses better, and in particular, more homogeneous, strength properties. However, steel also has a higher thermal conductivity than wood, and as a result, steel girders are inevitably constructed to conduct more heat in structures than wood or similar fiber-containing materials. In particular, weather conditions may impose limitations on the use of wood compared to other structural materials.

[0011] Traditional approaches have involved bonding and screwing together wood and metal components. These two materials are partially joined by a plastic sheath. However, these technical solutions almost always present significant problems during disassembly and recycling.

[0012] For example, the use of additional connecting means, such as drilling holes in the girder to ultimately screw together the individual components of the composite girder, has significant drawbacks. In such cases, the holes required for screwing can crack, potentially leading to unavoidable cracked cross-sections that can become a weakness in the structural integrity. Furthermore, composite girders constructed using connecting means also result in increased manufacturing costs. [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] From the above, it can be seen that the objectives of the present invention are conflicting: overcoming the shortcomings of the prior art and providing a device that combines the predetermined advantageous properties of fiber composite materials, particularly wood and metal. In some cases, the objective of the present invention is to overcome this conflict of objectives. In some cases, another objective of the present invention is to provide a long-lasting girder with improved thermal and strength properties for environmentally friendly building and construction projects, in which case it is necessary to avoid the occurrence of load-bearing cracks that impair the durability of the girder. In some cases, another objective of the present invention is to realize a device, particularly a composite girder, that is particularly easy to manufacture but can also be disassembled or recycled. [Means for solving the problem]

[0014] These and other problems are solved by the apparatus and method having the features of the independent claims.

[0015] The present invention is particularly based on the observation that hygroscopic fiber composite materials, such as wood, have the characteristic of undergoing a significant change in dimensions when they absorb polar fluids, i.e., liquids or gases, particularly when they absorb water, due to contact with water or changes in humidity and / or temperature.

[0016] The incorporation of polar fluids into a fiber composite structure increases the volume of the material. In the context of this invention, this volume increase is sometimes referred to as swelling. These swelling phenomena can be achieved not only with water, but also with various polar liquids and substances such as salt solutions, alcohols, and ammonia. Conversely, the removal of liquid from a fiber composite material causes a decrease in volume, also known as shrinkage.

[0017] In this case, the change in volume occurs only slightly in the longitudinal direction, i.e., in the direction of the fibers of the fiber composite material, and mainly perpendicular to the direction of the fibers. In particular, in the sense of the present invention, a swellable fiber composite material, such as wood, has a direction in which the fibers mainly extend. Swelling occurs particularly perpendicular to the direction in which the fibers mainly extend.

[0018] Swelling and shrinkage are generally considered major technical drawbacks in wood engineering. Thus, conventional techniques have often focused on counteracting changes in wood volume. However, surprisingly, within the scope of this invention, we have succeeded in advantageously utilizing the swelling properties of fiber composite materials to solve at least one of the aforementioned problems.

[0019] The apparatus according to the present invention optionally comprises an outer object in the shape of a hollow molded product having an internal space, and a core object disposed within the internal space, wherein the core object has or is composed of a fibrous composite material, in particular wood, that is swellable upon contact with a liquid. In some cases, particularly in the operating state, the core object is defined to swell with the liquid within the internal space, and the pressure generated by this swelling is applied to the outer object. In an advantageous embodiment, the core object is composed of or has wood. Alternatively, or in addition thereto, another material, in particular a bio-derived material or an industrial material, which causes a corresponding increase in volume by absorption of water, other liquids or gases, or by a chemical reaction, may also be used.

[0020] The swelling properties of the core object, and in particular its moisture absorption properties, make it possible to sustainably connect the core object to the outer object. Specifically, this makes it possible to achieve a connection between the core object and the outer object, particularly the inner surface of the outer object, by at least friction, and in particular by shape matching and friction.

[0021] The volume change due to swelling of the core material can, in some cases, cause plastic deformation of the core material in the region of the contact surface between the outer material and the core material. This contact surface and the pressing region adjacent to the boundary can also be called a compression region. In particular, compression of the core material, especially wood, occurring transversely to the fibers, significantly improves its strength and rigidity in the longitudinal direction relative to the fibers.

[0022] Besides wood, other materials such as nanocellulose can also be used as fiber composite materials. In some cases, the core material is composed of compressed plywood.

[0023] Depending on the curvature of the contact surface, the maximum relative stress within the core object acts near the outer surface of the core object, resulting in compressive deformation occurring in the compression region, thereby generating an outward force on the outer object. This force acts on the contact surface, particularly generating a normal force that causes frictional fastening of the girder in the lateral direction.

[0024] In the context of the present invention, a girder can be understood as a long extending member or structural part having, particularly in the long extending direction, a dimension larger than the maximum dimension perpendicular to the long extending direction. In the meaning of the present invention, a composite girder can be, for example, a composite member for supporting a load. Such a girder can be used, for example, as a girder for a building structure, as a pillar of an automobile chassis or an automobile body, as a supporting member of a lightweight building structure, as a girder of a mechanical structure, or as an equivalent thereof.

[0025] Optionally, in order to achieve a connection by an additional shape matching fastening between the outer object and the core object, a shape matching fastening member can be provided. Such a shape matching fastening member can be configured in various forms. For example, at least one shape matching fastening protrusion in the form of a rib can be arranged on the inner surface of the outer object. In the operating state of the present device, this shape matching fastening protrusion can be pushed into a part of the core object, thereby obtaining a connection by shape matching fastening. In some cases, the core object can also have a shape matching fastening recess with which the shape matching fastening protrusion engages. This shape matching fastening recess can be, for example, a groove.

[0026] These core object and outer object can, in some cases, extend along a common main extension direction, and the hollow outer object preferably surrounds the core object at least in the lateral direction, so that in some cases, a lateral connection between the outer object and the core object can be obtained. Therefore, this main extension direction is particularly regarded as the direction corresponding to the maximum spatial expansion of the present device. The lateral direction is particularly regarded as an orthogonal direction away from the main extension direction. The swelling of the core object can occur particularly in the radial and tangential directions.

[0027] The cross-section of a girder is interpreted as a cross-section that extends perpendicular to the direction of its elongation. For example, the outer object can be a pipe, in which case the cross-section of the outer object is circular and, in particular, closed. That is, the term closed cross-section means a continuous, unbroken cross-section, such as the cross-section of a pipe.

[0028] In some cases, during operation, the core object is defined to exert internal pressure on the outer object. A pressure distributed as uniformly as possible allows for the formation of a wide compression zone where compressive deformation occurs.

[0029] It is also possible to specify that the outer object has a closed cross-section. In this way, it is possible to ensure that deformation of the cross-section is sufficiently avoided when loading is applied to the composite girder. Furthermore, a closed cross-section ensures a uniform distribution of pressure between the inner surface of the core object and the outer object.

[0030] In particular, in the operating state, the pressure exerted by the core object on the outer object is at least 3 N / mm 2 In particular, at least 5 N / mm 2 or at least 10 N / mm 2 It is defined that, in this way, under normal frictional conditions, a sufficiently large normal force can be generated between the wood and the steel, and as a result, the core body is held within the outer body.

[0031] In some cases, the core object is defined to be fixed within the internal space during operation. This allows the core object to be held particularly stably within the outer object, even when a particularly high load is applied to the composite girder, without changing its shape and without causing relative movement of the contact surfaces due to girder deformation.

[0032] Advantageously, the outer object is specified to be constructed as a metal formwork, particularly as a steel formwork. This allows for the deployment of an outer object that is particularly well suited to buildings or other structures, such as the structure of an automobile, a machine, or a piece of equipment. In some cases, the device can be used as a lintel, and thus, for example, as a substitute for a brick or steel lintel.

[0033] In some cases, the core object is defined as being able to be inserted into and / or removed from the internal space in the joined state, and in the operating state, the core object swells more due to the absorption of liquid than in the joined state, or in the operating state, the core object has a greater liquid content than in the joined state, or both. In the joined state, the core object is particularly loosely housed within the outer object, and in particular, there is no frictional fastening between the core object and the inner surface of the outer object.

[0034] In particular, the dimensions of the core object are selected so that, in the joined state, the core object can be inserted into or fitted into the internal space of the outer object, for example, into a molded tube, an extruded product, etc. In some cases, the shape of the core object is selected so that the desired cross-section is created by the shrinkage of the material as the liquid content decreases.

[0035] Optionally, in the joined state, the core object and the internal space may have a play fit, and in some cases, the core object may be undersized relative to the internal space. This allows the scale of frictional fastening between the core object and the outer object in the swollen state to be determined by the manufacturing method. Furthermore, in the joined state, the core object can be easily removed from the internal space of the outer object.

[0036] In its operational state, the core object can be defined as completely filling the internal space of the outer object. In this way, the outer surface of the core object can be completely surrounded by the outer object, thereby achieving a strong connection between these objects.

[0037] In some cases, the core object is specified to be liquid-tightly sealed during operation. In this way, the core object can be protected from liquid loss and swelling reduction during the swollen state. In particular, this allows for the sustained stability of the device.

[0038] Advantageously, the core object is defined as being liquid-tightly sealed by the outer object and by at least one sealing member positioned on the outer object. This allows for further measures to prevent the loss of liquid. Alternatively, or in addition to this, the core object can be liquid-tightly sealed by coating. In connection with the present invention, liquid-tight means, in particular, the property of a material that is impermeable to liquids, especially liquids that cause swelling of the core object. For example, if the liquid is water, liquid-tight means, in particular, that the material is impermeable to water in both liquid and gaseous forms.

[0039] In some cases, the liquid is specified to be selected from one or more of the following: water, salt solution, alcohol, and ammonia. Water is the most advantageous liquid, as it allows us to utilize the hygroscopic properties of the wood.

[0040] In particular, the core object is defined to have a compression region along its outer circumference. As a result, the deformation of the core object can generate a normal force for frictional fastening. Furthermore, the mechanical properties of the core object's material are further improved in the compression region.

[0041] In some cases, the pressure generated by swelling is specified to increase the stress along the contour of the cross-section of the outer object. In this way, a device with pre-applied stress can be constructed.

[0042] One or more of the following can be specified: the outer surface of the core object is in at least partial direct contact with the inner surface of the outer object; and a connecting layer, such as an adhesive layer, is placed between the outer surface of the core object and the inner surface of the outer object. This allows measures to be taken at the contact surface to prevent relative movement between the core object and the outer object. In some cases, it may also be specified that the surface of the core object is treated to improve the connection by friction. For example, the surface of the core object can be roughened.

[0043] The frictional fastening between the outer object and the core object can also be improved by coating the surface of the wood with a substance that increases the coefficient of friction or adhesive properties on the inside of the outer object. A substance that increases the coefficient of friction may, for example, be a coating containing corundum. A substance that increases adhesive properties may, for example, be an adhesive.

[0044] In particular, when enhancing adhesive properties, it can be advantageous to apply a corresponding coating to the inside of the outer object. The interaction between the two coatings triggers a chemical reaction, thereby increasing the coefficient of friction or bonding the two materials together.

[0045] In some cases, oxidation of the outer surface of the core object and / or the inner surface of the outer object can improve the bond between the core object and the outer object.

[0046] In some cases, chemical treatment of the surface of the core object can improve the bond between the core object and the outer object. Furthermore, in some cases, the treated core object reacts with the inner surface of the outer object.

[0047] In some cases, the connection between the core object and the outer object can be improved by mechanical processing of the outer object, for example, by embossing and / or rolling.

[0048] Additional sensors, particularly pressure sensors, that react to a surface or point, can be attached to the contact surface between the core object and the outer object, for example, to monitor the swelling state of the core object.

[0049] The outer surface of the core object can also be considered a support for conductive paths that carry electric currents and signals.

[0050] In some cases, the core object is configured as a hollow object, which is defined to have a hollow space that extends, in some cases, almost in the direction of its elongation, and in particular, is open on at least one side. This allows the liquid that swells the core object to flow in more easily and, if necessary, to flow out again. In some cases, the core object can be configured with a hollow shape for its contour.

[0051] This hollow space can, in some cases, be used to insert a tube or conductive path into the device for transporting gas or liquid after the swelling process.

[0052] In this hollow space, an inner molded object, such as a tube, can be placed, if necessary. In some cases, the core object also applies pressure to this inner molded object due to swelling.

[0053] In some cases, the liquid is specified to be water, and the liquid content of the core object in the operating state is at least 1 weight percent, in particular 5 weight percent, and preferably 10 weight percent, more than in the bonded state. This can, in some cases, achieve sufficient swelling.

[0054] In particular, it is stipulated that the outer object and the core object are connected to each other by frictional fastening.

[0055] In some cases, the outer object is defined to have at least one shape-matching fastening member, particularly a shape-matching fastening projection, on its inside that connects the outer object and the core object by shape-matching fastening.

[0056] In some cases, the core object is defined to have at least one shape-matching fastening recess that engages with a shape-matching fastening projection.

[0057] In some cases, the core material is specified to be modified by heat, particularly by heat treatment to at least 120°C, and preferably about 200°C. In particular, the core material is modified by heat treatment between 120°C and 250°C. In some cases, the core material is modified by heat treatment for at least 5 minutes, and preferably at least 10 minutes. In some cases, the core material is modified by heat treatment for at most 30 minutes. This can improve the mechanical properties of the core material.

[0058] Furthermore, in some cases, the present invention comprises an apparatus, in particular a method for manufacturing a composite girder. This apparatus comprises, in particular, an outer object having a hollow contour shape with an internal space, and a core object disposed within the internal space, wherein the core object has or is made of a fibrous composite material, in particular wood, that can swell upon contact with a liquid. In some cases, the method is (a) A step of preparing a core object, wherein the core object has a first liquid content, (b) The process of inserting the core object into the internal space of the outer object, (c) A step of increasing the liquid content of the core object so that the core object swells with the liquid, and the pressure generated by the swelling is applied to the outer object, wherein the core object has a second liquid content. It has such a feature. In this way, the apparatus according to the present invention can be advantageously configured, in which, in particular, a frictional connection occurs between the outer object and the core object.

[0059] In some cases, it is specified that the liquid is water, and that the content of the second liquid is at least 1 weight percent, in particular at least 5 weight percent, and preferably at least 10 weight percent, greater than the content of the first liquid. In this way, sufficient swelling can be achieved, in particular, to connect the outer object and the core object.

[0060] In some cases, step (b) is defined to have a play fit between the core object and the internal space. In this way, the normal force acting for the connection, particularly in the operating state, can be determined.

[0061] In some cases, the liquid is specified to be water, and the content of the first liquid is at most 10 weight percent, in particular at most 5 weight percent, and the content of the first liquid is below the equilibrium moisture content of the core fibrous composite material at a temperature of 20°C and a relative humidity of 50%. In particular, the content of the first liquid can be at least 5 weight percent, and in some cases at least 10 weight percent, below the equilibrium moisture content of the core fibrous composite material at a temperature of 20°C and a relative humidity of 50%.

[0062] In some cases, moisture is largely or completely removed from the core material by drying or other means. This removal of moisture reduces the volume of the wood, thereby allowing the core material to be inserted into the internal space of the outer material in the joint.

[0063] In some cases, this method may be even more effective. (d) The process is defined as having a step of forming a shape-matching fastening member by deformation of the outer object. In this way, an additional restraining force can be created between the outer object and the core object, locking these objects together.

[0064] In some cases, the method may further include (d) a step of rolling the apparatus. This allows the core object to be compressed, which further improves its mechanical properties.

[0065] In some cases, the core material is moistened with liquid and / or gaseous water between steps (a) and (b).

[0066] In some cases, the core material may be chemically treated with, for example, ammonia before step (b) to achieve better swelling.

[0067] In some cases, the present invention further relates to an apparatus, in particular a method for dismantling a composite girder. This apparatus may include an outer object with a hollow contour shape having an internal space, and a core object disposed within the internal space, wherein the core object has or is composed of a fibrous composite material, in particular wood, that can swell upon contact with a liquid. In some cases, this method may include: (a) A step of preparing the apparatus, wherein the core object swells with liquid within its internal space, and the pressure generated by this swelling is applied to the outer object, and at that time the core object has a second liquid content, (b) A step of reducing the liquid content of the core material so that the core material has a first liquid content, (c) A process of removing the core object from the outer object, It has.

[0068] This allows the device to be disassembled again, and its individual components can be used separately in some cases.

[0069] In some cases, step (b) specifies that the liquid content of the core object is reduced by heating the core object. This reduces the pressure acting between the outer object and the core object, and as a result, frictional fastening and / or shape-matching fastening does not occur between the outer object and the core object.

[0070] In some cases, the liquid is specified to be water, and the content of the second liquid is specified to be at least 1 weight percent, in particular at least 5 weight percent, and favorably at least 10 weight percent, higher than the content of the first liquid. In this way, it is possible to cause the contraction necessary to break the linkage, in particular.

[0071] In some cases, process (c) may specify that the core object and the internal space have a play fit. In one apparatus, it may also be specified that the fibers of the core object extend in approximately the principal stretching direction of the core object.

[0072] The cross-sections of the core object and / or outer object can be quadrilateral, in particular rectangular or square, circular, polygonal, hyperbolic, convex, concave, trapezoidal, elliptical, hexagonal, various shapes, rhombic, triangular, T-shaped, U-shaped, or polygonal. This allows for the preparation of cross-sections suitable for various purposes.

[0073] In some cases, it is defined that, in the operating state, the compression energy due to the mechanical structure of the core object is equal to the expansion energy due to the mechanical structure of the outer object.

[0074] In some cases, the radial cross-section of the device is defined to have the same moment of inertia about two principal stress axes.

[0075] A core object can be defined as being composed of one or more parts. For example, a core object can be defined as having multiple parts that can be separated from each other.

[0076] In some cases, one or more of the following conditions may be specified: the cross-section of the device has different moments of inertia around two principal stress axes, and the shape of the core object conforms to the shape of the internal space.

[0077] In some cases, the device is specified to have dimensions that, in the joined state, allow for the insertion and removal of the core object into the internal space of the outer object, and that, in the operating state, have expanded dimensions resulting in a rigid connection between the core object and the outer object. In some cases, these dimensions are oversized or undersized tolerances.

[0078] In some cases, the addition of liquid to the core object is defined as reversible, and in such cases, the core object is removed from the outer object again after reducing the liquid content within the core object, particularly the humidity of the wood.

[0079] In additional embodiments, the following features may be specified in the apparatus and / or method of the present invention, either in addition to or instead of the above.

[0080] In some cases, recyclable joining techniques are provided for composite materials of wood and metal. The core material and the outer material are joined, in particular, by a hydrothermal method, and in some cases, can be decomposed again. Wood, in particular, being a hygroscopic material, has the property of changing volume when it absorbs moisture upon contact with water, or when there are changes in humidity in the air and / or when there are changes in temperature.

[0081] The volume of a core object can be increased by accumulating water within its wooden structure. This property can be called swelling.

[0082] In the case of water, the increase in volume sometimes occurs within the moisture content range of wood, which is the saturation range of the fibers, from 0 to approximately 30 weight percent. Above this value, no change in volume is usually observed.

[0083] In some cases, the core material is pre-compressed to promote compression after swelling. The compressive pressure generated during wood swelling (the theoretical compressive pressure of lignified cell walls is approximately 500 N / mm²) 2 (This is the case) and (depending on the type of wood, approximately 1 to 15 N / mm 2 Due to the low lateral compressive strength of wood (within a certain range), the wood material of the core object may, in some cases, be compressed by the outer object.

[0084] Plastic deformation in the radial or tangential direction of wood can occur more easily under high humidity or high temperature conditions, or after chemical pretreatment.

[0085] In some cases, a multilayered core object consisting of pre-compressed wood layers and other materials such as ceramics, plastics, metals, or metal foams may be constructed.

[0086] The device can also be deformed by applying external compressive pressure. This can, in some cases, change the moment of inertia or selectively compress the core object. The core object can be joined to the outer object by a swelling process or additional molding process, through shape-matching fastening and friction fastening. This joining can also be improved by special surface shaping such as roughening or undercutting.

[0087] Furthermore, this device can also be plastically deformed using bending equipment, such as a profile bending machine.

[0088] Pre-compression of the core material can, in some cases, improve rigidity and strength. In particular, wooden bodies or core materials can be compressed in their peripheral regions through the joining process, thereby improving strength and rigidity, as well as the overall mechanical properties of the device. A major advantage of this device is that, in particular, when the device is subjected to excessive stress, ductile fracture occurs in a way that increases energy absorption.

[0089] In particular, the amount of fracture energy that can be absorbed can be further increased by compressing the core material. After the volume increase, the device is sealed on both sides, thereby maintaining the swollen state of the wood through the sealing effect between the metal and the sealing material, such as rigid PU foam or other plastics, which prevents penetration.

[0090] The front of the outer object can be sealed by covers of various shapes made of various materials. These covers can be connected to the outer object by friction fastening, shape-matching fastening and / or material fastening.

[0091] In the case of friction fastening and material fastening, the cover can be easily removed again by rotating, peeling, or heating.

[0092] The apparatus can also be disassembled or taken apart again by removing the liquid-tight seal of the core object and exposing it to atmospheric or physical conditions, causing the core object to shrink again due to the loss of moisture or other liquids. This shrinkage process may, in some cases, be continued until the two joints can be separated from each other again.

[0093] The main advantage of this method is that, in some cases, metal parts or outer components and wooden parts or core components can be supplied for secondary use or recycling. Furthermore, the improved mechanical properties of this composite material can, in some cases, reduce the dimensions of the components and save material.

[0094] If the outer material is steel, the recycling process in a blast furnace requires the supply of carbon dioxide and heat. The energy and chemical components stored in the core material allow for energy and coal savings in the recycling process.

[0095] The outer object may be made of, or may have, another non-swelling, penetration-resistant material such as ceramic, plastic, or fiber-reinforced plastic.

[0096] The apparatus of the present invention, compared to conventional geometrically similar steel girders, may, in some cases, To improve deflection by at least 2%, and in some cases 8%, when the load and weight are approximately the same, For the same weight, raw material costs can be reduced by up to 40%, For the same weight, reducing carbon dioxide emissions during manufacturing by up to 20%, It is possible to achieve one or more of the following advantages.

[0097] When using large core materials, it may be possible to reduce raw material costs by up to 50% and carbon dioxide emissions by up to 40% in some cases.

[0098] Further features of the present invention will become apparent from the description of the embodiments, the drawings and the claims.

[0099] The present invention will be described in detail below, based on examples that are not exclusive but merely illustrative. [Brief explanation of the drawing]

[0100] [Figure 1a] Schematic diagram of the configuration of the first embodiment of the apparatus according to the present invention in operation. [Figure 1b] Schematic diagram of the first embodiment of the device in the bonded state. [Figure 2a] Schematic diagram of the configuration of a second embodiment of the apparatus according to the present invention in an operating state. [Figure 2b] Schematic diagram of the second embodiment of the device in the bonded state. [Figure 3a] Schematic diagram of the configuration of a third embodiment of the apparatus according to the present invention in operation. [Figure 3b] Schematic diagram of the third embodiment of the device in the bonded state. [Figure 4a] Schematic diagram of the configuration of the fourth embodiment of the apparatus according to the present invention in operation. [Figure 4b] Schematic diagram of the fourth embodiment of the device in the bonded state. [Modes for carrying out the invention]

[0101] Unless otherwise specified, these drawings illustrate the features of the composite girder 1, outer body 2, core body 3, inner space 4, inner surface 5, outer surface 6, shape-matching fastening projection 7, hollow space 8, inner molded body 9, and outer surface 10.

[0102] Figure 1a illustrates the configuration of a first embodiment of the apparatus according to the present invention in an operating state. Figure 1a shows the apparatus in a schematic cross-sectional view, and this cross-section is located approximately perpendicular to the direction in which the apparatus extends.

[0103] This device is configured as a composite girder 1 with a circular cross-section and includes an outer object 2 in the shape of a hollow molded body having an internal space 4. A core object 3 is placed within this internal space 4. This core object 3 is capable of swelling upon contact with liquid and is made of wood in this embodiment. In Figure 1a, the composite girder is shown in operation, i.e., the core object 3 is swollen. In this state, the core object 3 within the internal space 4 is swollen with water, and this swelling applies pressure to the outer object 2. The outer surface 6 of the core object 3 is in overall direct contact with the inner surface 5 of the outer object 2.

[0104] In another configuration not shown, a connecting layer, such as an adhesive layer, is placed between the outer surface 6 of the core object 3 and the inner surface 5 of the outer object 2.

[0105] In this embodiment, the outer object 2 is constructed as a tubular steel molded product. The core object 3 is a long, nearly cylindrical wooden rod.

[0106] The core object 3 is liquid-tightly sealed within the internal space 4 of the outer object 2, and plastic sealing parts (not shown) are provided at the two open ends of the outer object 2. This allows the liquid content of the core object 3 to be kept nearly constant even when external conditions change.

[0107] Figure 1b illustrates an embodiment of the apparatus according to the present invention in a joined state. In this state, the outer surface 6 of the core object 3 is spaced apart from the inner surface 5 of the outer object 2; that is, there is a play fit between the core object 3 and the inner surface 5 of the outer object 2. For other features, please refer to the description of Figure 1a.

[0108] In particular, when manufacturing this device or the composite girder 1, the device can be put into a joined state. In this joined state, the core object 3 can be inserted into the internal space 4 of the outer object 2. As the moisture content increases, the composite girder 1 moves into an operational state, and as a result, the core object 3 presses its outer surface 6 against the inner surface 5 of the outer object 2.

[0109] In this embodiment, the moisture content of the core object 3 is approximately 25% by weight in the operating state and approximately 10% by weight in the bonded state. When this composite girder is dismantled, at least one sealing portion is removed. Subsequently, the excess moisture can be removed, causing the core object 3 to shrink, thereby achieving a bonded state that allows the core object 3 to be removed again from the internal space 4 of the outer object 2. This moisture removal can be accelerated by heating the apparatus.

[0110] Figure 2a schematically illustrates the configuration of a second embodiment of the apparatus according to the present invention in an operating state. Figure 2b illustrates the second embodiment of the apparatus in a joined state. Figures 2a and 2b each illustrate the apparatus in a schematic cross-sectional view, where the cross-section is located approximately perpendicular to the direction in which the apparatus extends.

[0111] The composite girder 1 according to this second embodiment closely matches the composite girder according to the first embodiment, which has been described in detail.

[0112] Unlike the first embodiment, in the second embodiment, the core object 3 and the outer object 2 have a square cross-section.

[0113] Furthermore, rib-shaped, shape-matching fastening projections 7 are positioned on the inner surface 5 of the outer object 2. In operation, these shape-matching fastening projections 7 are pressed into the surface of the core object 3, thereby additionally realizing a shape-matching fastening connection between the core object and the outer object. These ribs are arranged at regular intervals along the direction in which the composite girder 1 extends.

[0114] Furthermore, unlike the first embodiment, the core object 3 is not liquid-tightly sealed into the internal space 4 of the outer object 2. In this embodiment, both sides of the outer object 2 are open. In this embodiment, frictional fastening between the core object 3 and the outer object 2 is achieved by ensuring that the moisture content of the core object 3 in the joined state is below the moisture content equal to the equilibrium moisture content of the core object material at a temperature of 20°C and a relative humidity of 50%. That is, the core object is dried, and as a result, its moisture content is, in particular, below 5 weight percent.

[0115] In this joined state, there is no longer any connection between the shape-matching fastening member 7 and the core object 3 through shape-matching fastening. In this joined state, the core object 3 can be inserted into the internal space 4 of the outer object. Subsequently, the composite girder 1 remains under ambient environmental conditions, and the moisture content of the core object 3 gradually increases until the moisture content matches the equilibrium moisture content. After that, the device becomes operational, and the same effects as in the first embodiment are achieved. In contrast, liquid-tight sealing is not required, which makes manufacturing even easier.

[0116] To dismantle this device, the composite girder 1 can be heated, which reduces the liquid content of the core object 3.

[0117] Figure 3a schematically illustrates the configuration of a third embodiment of the apparatus according to the present invention in an operating state. Figure 3b illustrates the third embodiment of the apparatus in a joined state. Figures 3a and 3b each illustrate the apparatus in a schematic cross-sectional view, where the cross-section is located approximately perpendicular to the direction in which the apparatus extends.

[0118] This third embodiment is almost identical to the second embodiment, differing in that the core object 3 is configured as a hollow object having a hollow space 8. This facilitates changes in moisture content, and a larger free surface area allows for particularly faster changes in moisture content. In this embodiment, the core object 3 is realized as a box-shaped molded object. This hollow space 8 can be used for pipes, piping, wiring and their equivalents.

[0119] In embodiments not shown, shape-matching fastening protrusions can also be provided in the implementation configuration.

[0120] Furthermore, unlike the second embodiment, the shape-matching fastening projection 7 is not provided.

[0121] Figure 4a schematically illustrates the configuration of a fourth embodiment of the apparatus according to the present invention in an operating state. Figure 4b illustrates the fourth embodiment of the apparatus in a joined state. Figures 4a and 4b each illustrate the apparatus in a schematic cross-sectional view, where the cross-section is located approximately perpendicular to the direction in which the apparatus extends.

[0122] This fourth embodiment is almost identical to the third embodiment, differing in that the outer object 2 and the core object 3 are configured as hollow cylinders. In this embodiment, an inner molded object 9, which is a steel pipe, is placed within the hollow space 8 of the core object 3.

[0123] In operation, as illustrated in Figure 4a, the core object 3 presses against the inner surface 5 of the outer object 2 and the outer surface 10 of the inner molded object 9 due to swelling.

[0124] In this embodiment, the device can be used as a structural component that supports a load, and at the same time, as a pipe for transporting liquids or gases, such as a water supply pipe. While this application relates to the invention described in the claims, it also includes the following other aspects. 1. An outer object (2) having a hollow molded shape with an internal space (4), and a core object (3) disposed within this internal space (4), wherein the core object (3) is made of a fibrous composite material, particularly wood, that can swell upon contact with a liquid, or an apparatus (1) made therefrom, particularly a composite girder (1), The apparatus is characterized in that, in its operating state, the core object (3) swells with liquid within the internal space (4), and the pressure generated by this swelling is applied to the outer object (2). 2. In the apparatus described in item 1 above, The apparatus is characterized in that the core object (3) applies internal pressure to the outer object (2) when in operation. 3. In the apparatus described in 1 or 2 above, The apparatus is characterized in that the outer object (2) has a closed cross-section. 4. In any of the devices described in items 1 to 3 above, The pressure exerted by the aforementioned core object on the outer object during operation is at least 3 N / mm². 2 In particular, at least 5 N / mm 2 or, in particular, at least 10 N / mm 2 A device characterized by being such. 5. In the apparatus (1) described in any one of items 1 to 4 above, The apparatus is characterized in that the aforementioned core object (3) is fixed within the internal space (4) when in operation. 6. In the apparatus (1) described in any one of items 1 to 5 above, The apparatus is characterized in that the aforementioned outer object (2) is made of a metal molded product, in particular a steel molded product. 7. In the apparatus (1) described in any one of items 1 to 6 above, The apparatus is characterized in that, in the bonded state, the core object (3) can be inserted into and / or removed from the internal space (4), and in the operating state, the core object (3) swells more than in the bonded state due to the absorption of liquid, or the core object (3) has a higher liquid content in the operating state than in the bonded state, or both. 8. In the apparatus (1) described in any one of items 1 to 7 above, The apparatus is characterized in that, when the core object (3) and the internal space (4) are joined, there is a play fit, and in some cases, the core object (3) is undersized relative to the internal space (4). 9. In the apparatus (1) described in any one of items 1 to 8 above, The apparatus is characterized in that the core object (3) completely fills the internal space (4) of the outer object (2) when in operation. 10. In the apparatus (1) described in any one of items 1 to 9 above, The apparatus is characterized in that the aforementioned core object (3) is liquid-tightly sealed in the operating state. 11. In any of the devices described in items 1 to 10 above, The apparatus is characterized in that the core object is liquid-tightly sealed by the outer object (2) and by at least one closing member disposed on the outer object (2). 12. In the apparatus described in any one of items 1 to 11 above, The apparatus is characterized in that the aforementioned liquid is selected from one or more of the following: water, salt solution, alcohol, and ammonia. 13. In any of the devices described in items 1 to 12 above, The apparatus is characterized in that the aforementioned core object (2) has a contraction region along its outer circumference. 14. In the apparatus (1) described in any one of items 1 to 13 above, The apparatus is characterized in that the pressure generated by the aforementioned swelling increases the stress along the periphery of the molded cross-section of the outer object (2). 15. In the apparatus (1) described in any one of items 1 to 14 above, An apparatus characterized by one or more of the following: the outer surface (6) of the core object (3) is in at least partially direct contact with the inner surface (5) of the outer object (2); and a connecting layer, such as an adhesive layer, is disposed between the outer surface (6) of the core object (3) and the inner surface (5) of the outer object (2). 16. In the apparatus (1) described in any one of items 1 to 15 above, The apparatus is characterized in that the aforementioned core object (3) is configured as a hollow object, and this hollow object has, in some cases, a hollow space (8) that extends almost in the direction of its elongation, particularly with at least one side open. 17. In the apparatus (1) described in any one of items 1 to 16 above, An apparatus characterized in that an inner molded object (9) is placed within the aforementioned hollow space (8), and the core object (3) applies pressure generated by its swelling to the inner molded object (9). 18. In the apparatus (1) described in any one of items 1 to 17 above, The apparatus is characterized in that the aforementioned liquid is water, and the liquid content of the core object (3) in the operating state is at least 1 weight percent greater than that in the bonded state. 19. In any of the devices described in items 1 through 18 above, The apparatus is characterized in that the outer object (2) and the core object (3) are connected to each other by frictional fastening. 20. In any of the devices described in items 1 through 19 above, The apparatus is characterized in that the outer object (2) has at least one shape-matching fastening member, particularly a shape-matching fastening projection (7), on its inner side (5) for connecting the outer object (2) and the core object (3) by shape-matching fastening. 21. In the apparatus described in item 20 above, The apparatus is characterized in that the core object (3) has at least one shape-matching fastening recess that engages with a shape-matching fastening projection (7). 22. An apparatus (1), particularly a composite girder (1), comprising an outer object (2) in the shape of a hollow molded product having an internal space (4), and a core object (3) disposed within this internal space (4), wherein the core object (3) is made of a fibrous composite material, particularly wood, that can swell upon contact with a liquid, or an apparatus (1) made therefrom, (a) A step of preparing a core object (3), wherein the core object (3) has a first liquid content, (b) The process of inserting the core object (3) into the internal space (4) of the outer object (2), (c) A step of increasing the liquid content of the core object (3) so that the core object (3) swells with the liquid, and the pressure generated by the swelling is applied to the outer object (2), wherein the core object has a second liquid content. A method of having. 23. In the method described in 22 above, A method characterized by one or more of the following: the aforementioned liquid is water, and the content of the second liquid is at least 1 weight percent, in particular at least 2 weight percent, greater than the content of the first liquid. 24. In the method described in 22 or 23 above, A method characterized in that, in step (b) above, the core object (3) and the internal space (4) have a play fit. 25. In any one of the methods described in items 22 to 24 above, A method characterized by one or more of the following: the liquid is water; the content of the first liquid is at most 10 weight percent, in particular at most 5 weight percent; and the content of the first liquid is below the equilibrium water content of the fiber composite material of the core object at a temperature of 20°C and a relative humidity of 50%. 26. In any one of the methods described in items 22 to 25 above, (d) A step of forming a shape-matching fastening member by deformation of the outer object (2) A method characterized by further comprising the following. 27. An outer object (2) having a hollow molded shape with an internal space (4), and a core object (3) disposed within this internal space (4), wherein the core object (3) is made of a fibrous composite material, particularly wood, that can swell upon contact with a liquid, or an apparatus made therefrom, particularly in a method for dismantling a composite girder, (a) A step of preparing the apparatus (1), wherein the core object (3) swells with liquid in the internal space (4), and the pressure generated by this swelling is applied to the outer object (2), and at that time the core object (3) has a second liquid content, (b) A step of reducing the liquid content of the core object (3) so that the core object (3) has a first liquid content, (c) A step of removing the core object (3) from the outer object (2), A method of having. 28. In the method described in 27 above, A method characterized in that the reduction of the liquid content of the core substance (3) in step (b) is carried out by heating the core substance (3) to a temperature above 50°C, preferably above 100°C. 29. In the method described in 27 or 28 above, A method characterized in that the aforementioned liquid is water, and the content of the second liquid is at least 1 weight percent, in particular at least 2 weight percent, greater than the content of the first liquid. 30. In any one of the methods described in items 27 to 29 above, A method characterized in that, in step (c), the core object (3) and the internal space (4) have a play fit.

Claims

1. An apparatus comprising an outer object (2) in the shape of a hollow molded product having an internal space (4), and a core object (3) disposed within this internal space (4), The aforementioned core object (3) has or is composed of a fibrous composite material that can swell upon contact with a liquid, i.e., wood. The core object (3) swells within the internal space (4) due to the liquid, and the pressure generated by this swelling is applied to the outer object (2), resulting in the core object (3) being fixed within the internal space (4). In the said device, The apparatus is characterized in that the core object is liquid-tightly sealed by the outer object (2) and by at least one closing member disposed on the outer object (2).

2. In the apparatus according to claim 1, The apparatus is characterized in that the outer object (2) has a closed cross-section.

3. In the apparatus (1) according to claim 1 or 2, The apparatus is characterized in that the aforementioned outer object (2) is made of a metal molded product or a steel molded product.

4. In the apparatus according to claim 1 or 2, The apparatus is characterized in that the aforementioned liquid is selected from one or more of the following: water, salt solution, alcohol, and ammonia.

5. In the apparatus according to claim 1 or 2, The apparatus is characterized in that the aforementioned core object (3) has a compression region along its outer circumference.

6. In the apparatus according to claim 1 or 2, The apparatus is characterized in that the pressure generated by the aforementioned swelling increases the stress along the periphery of the molded cross-section of the outer object (2).

7. In the apparatus (1) according to claim 1 or 2, An apparatus characterized by one or more of the following: the outer surface (6) of the core object (3) is in at least partially direct contact with the inner surface (5) of the outer object (2); and a connecting layer or adhesive layer is disposed between the outer surface (6) of the core object (3) and the inner surface (5) of the outer object (2).

8. In the apparatus (1) according to claim 1 or 2, The apparatus is characterized in that the aforementioned core object (3) is configured as a hollow object, and this hollow object extends in substantially the direction in which it elongates, or has a hollow space (8) that is open on at least one side.

9. In the apparatus (1) described in claim 7, An apparatus characterized in that an inner molded object (9) is placed within the aforementioned hollow space (8), and the core object (3) applies pressure generated by its swelling to the inner molded object (9).

10. In the apparatus according to claim 1 or 2, The apparatus is characterized in that the outer object (2) and the core object (3) are connected to each other by frictional fastening.

11. In the apparatus according to claim 1 or 2, The apparatus is characterized in that the outer object (2) has at least one shape-matching fastening member or shape-matching fastening projection (7) on its inner side (5) for connecting the outer object (2) and the core object (3) by shape-matching fastening, and the core object (3) has at least one shape-matching fastening recess that engages with the shape-matching fastening projection (7).

12. A method for manufacturing an apparatus comprising an outer object (2) in the shape of a hollow molded product having an internal space (4), and a core object (3) disposed within this internal space (4), The core object (3) has or is composed of a fibrous composite material that can swell upon contact with a liquid, i.e., wood. The above method involves the following steps: (a) A step of preparing a core object (3), wherein the core object (3) has a first liquid content, (b) The process of inserting the core object (3) into the internal space (4) of the outer object (2), (c) A step of increasing the liquid content of the core object (3) so that the core object (3) swells with the liquid, and the pressure generated by the swelling is applied to the outer object (2), wherein the core object has a second liquid content. (d) A step of sealing the core object (3) in a liquid-tight manner by the outer object (2) and by at least one closing member placed on the outer object (2), A method of having.

13. In the method according to claim 12, The aforementioned liquid is water, and A method characterized in that the content of the second liquid is at least 1 weight percent greater than the content of the first liquid, or at least 2 weight percent greater.

14. In the method according to claim 12 or 13, A method characterized in that, in step (b) above, the core object (3) and the internal space (4) have a play fit.

15. In the method according to claim 12 or 13, The aforementioned liquid is water, and A method characterized in that the first liquid content is at most 10 weight percent or at most 5 weight percent.

16. In the method according to claim 12 or 13, The aforementioned liquid is water, and A method characterized in that the first liquid content is below the equilibrium water content of the core fiber composite material at a temperature of 20°C and a relative humidity of 50%.

17. In the method according to claim 12 or 13, The process of forming a shape-matching fastening member by deformation of the outer object (2) A method characterized by further comprising the following.

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