EP0100845B1 - Reinforcing or supporting element for building material, in particular an electrode - Google Patents

Abstract

Reinforcing or carrier elements for plaster are used as electrodes in electro-osmotic dehumidification installations. The elements comprise a carrier body constituted by a flexible net having a surface of synthetic resin in contact with the plaster and the net has filamentary carrier materials incorporated therein. The synthetic resin is a conductive, essentially ion-free thermosetting resin of macromolecular structure, preferably an at least partially cross-linked acrylate polymer having a high surface roughness and containing a small amount of a plasticizer, and forms either the matrix or a coating of the flexible net. The filamentary carrier materials may be carbon or metal filaments. In the use of the dehumidification installation, a voltage alternating between a positive and a negative potential is conducted between the cathode and the anode, the time interval of the positive potential exceeding that of the negative potential.

Description

The invention relates to a reinforcing or supporting element for building materials, as described in the preamble of claim 1.

Reinforcing or supporting elements for building materials are known which consist of rod-shaped or net-shaped or lattice-shaped materials. For reinforcement of concrete structures, mainly mesh or mesh made of structural steel or as a plaster base, primarily fine metal meshes are used. If the metal grids are used as a plaster base, they are often coated with fired ceramic materials to ensure better adhesion of the plaster mortar. The disadvantage of these metallic plaster bases is that, due to different pH values, they are exposed to corrosion in the building structure and the different moisture conditions. In many cases, the arrangement of the grids in zones with different pH values leads to the formation of a galvanic element and thus to a field structure which causes the structures to be destroyed or the moisture to be drawn up from the ground into the structures. These adverse effects are particularly noticeable when the plaster base is used to renovate old historic buildings that have to be drained. It is therefore often necessary to install electrodes of dehumidification systems working on an electro-osmotic basis in addition to the plaster base in order to dehumidify the structure.

Numerous different methods of draining walls are in use today. As from a research work by the Austrian Institute for Building Research (Verlag Strassenbau, Chemie und Technik Verlagsgesellschaft mbH, Heidelberg 1967), the following options are differentiated: Plastering measures, ventilation processes, dehumidifiers, installation of sealing layers, pore filling, electroosmotic and other processes. The present invention belongs to the electroosmotic method, which is why briefly on the theoretical basis according to the above. Publication is received.

The electroosmotic processes use the phenomenon of electroosmosis to slow down the moisture rising in the capillaries of the masonry and to push it down. Polarization occurs at the interface between water and a solid, with a negative charge on the surface of the solid and a positive charge on the liquid particles. This charge (polarization) does not normally appear, only in an electric field does a migration occur, whereby the solids (as far as they are mobile) migrate to the positive anode (also known as electrophoresis), the liquid particles, especially if the solid particles on the Mobility are prevented, strive to migrate to the negative cathode.

Since the water z. B. always contains salts in the masonry, there is a conductivity, so that by appropriate choice of the electrode materials, galvanic elements can be produced, which cause the electroosmotic phenomena. Disadvantages are signs of corrosion and the limited life of the electrodes, and the fact that the device is maintenance-free is an advantage.

With the active methods, the electric field between the installed or attached electrodes is generated by external current. Corrosion can also occur here, but the problem that is solved today by using graphite or electrically conductive plastics.

The extensive patent literature deals with the arrangement and composition of the electrodes (DE-C 2 722 985, DE-C 2 603 135, DE-A 2703813, DE-A 2706193). DE-A 2 706 172 proposes electrodes with additional foils in order to prevent corrosion.

As can be seen from DE-A 2 705 814 and DE-C 2 503 670, the voltage that can be used in the active process is limited by the decomposition voltage, depending on the composition of the masonry and the salinity of the water, since electrolysis by decomposition of the Water would produce gases that the components in which the electrodes are installed, for. B. plaster, must destroy. According to DE-A 2 705 814, the formation of detonating gas could even lead to an explosion, so that a limit of 2.8 V is required. On the other hand, it would be desirable to increase the electric field by increasing the voltage in order to improve the desired effect. This is particularly necessary with old or very thick masonry or with very strong moisture pressure. The drying effect can also be achieved much more quickly by increasing the voltage.

The invention is based on a device for the electroosmotic drying of moist structures made of mineral raw materials - according to DD-A 47 791 - which works without the use of an external voltage. It comprises two barrier levels in the form of two electrodes, spaced apart from each other in a damp building.

The two barrier levels are electrically conductively connected to one another, the electrode forming the barrier level consisting of a metal and the electrode forming the other barrier level consisting of an electrically conductive non-metal. The metallic electrode can consist of iron or galvanized iron, the electrode of non-metal of graphite or of graphite dispersed in plastic or applied in a film. The electrode formed from non-metal can also be designed in the form of wire, tape, foil or mesh. The electric field to transport liquids in kapilla according to the electroosmotic principles Ren cavities is caused by the combination of the electrically conductive non-metal with a metal, which are built into a working galvanic element. The disadvantage here is that the electrode, which is made of non-metal, will set itself up as a cathode with respect to the metal due to its distance in the electrochemical voltage series of the metals from hydrogen. Accordingly, the anode - which is then formed by the metal, that is, the iron - continues to degrade and passivate, as a result of which the operating time of the known device is also very short.

The invention is based on the object of creating a reinforcement or support element for building materials of the type mentioned at the beginning, which can be used in areas with different or changing pH values and an intimate connection with the surrounding building materials enables, and moreover it should be possible to use this for a dehumidification system working on an electro-osmotic basis with external current.

This object of the invention is achieved by the features mentioned in claim 1. The surprising advantages of this solution are that the chemical-neutral electrode acts as an anode regardless of its distance in the electrochemical voltage series of the metals to hydrogen, since it is connected to an energy supply system at the positive pole. This not only prevents degradation of the anode, but also enables the electrode to be installed in building structures regardless of different pH values. At the same time, however, this also prevents electrochemical degradation in the area of the electrical field at the anode, so that the use of such an electrode is also possible in the renovation of old historical structures with moistened structures. Above all in that, depending on the design of the network and the mesh size, as well as the thread thickness or the distances between the openings of the electrode, this serves simultaneously as a reinforcing or supporting element for building materials. As a result, subsequent settlements between the individual building materials or the entire building body cannot hinder the intensive field build-up by the electrode according to the invention. If individual threads of the network are interrupted, the connection via the parallel threads and the power supply line extending in the longitudinal direction of the support body or the band-shaped network ensures the supply of external current and thus the field structure. In addition, in some cases it may be possible to save on the use of additional reinforcement or support elements when applying the plaster, since this function can be performed directly with the appropriate training. Furthermore, this design makes it possible that when using the reinforcement or support elements as electrodes, even in large-scale systems and at higher operating voltages, no disturbances due to electrolytic decomposition or hydrogen deposits on an anode can occur. The decisive factor here is the continuous coating of the mesh with conductive plastic. Thanks to the flexibility of the network, it can be easily adapted to different environmental conditions, such as different floor levels or building levels. This advantage comes to the fore especially when used for the renovation of dampened building structures. Since the coating of the mesh with the conductive plastic causes the voltage to be evenly distributed over the entire surface of the electrode, a large-area electrokinetic effect, for example a large-area electroosmosis, is achieved.

Another embodiment is described in the characterizing part of claim 2. This enables uniform, continuous contacting of the network, the power supply line having good conductivity and strength.

Furthermore, training according to claim 3 is also possible. As a result, the power supply lines improve the strength of the networks against mechanical stress and at the same time the conductivity. In addition, the use of titanium is characterized by the small electrochemical potential difference compared to hydrogen, so that the risk that a galvanic element can build up is further reduced.

However, further development according to claim 4 is also possible. This ensures an even power supply for the various power supplies and, above all, easily damages bridged power supplies.

Furthermore, an embodiment according to claim 5 is also provided. The high surface roughness has the advantage that there is an intimate connection of the surrounding building materials, in particular of the plastering mortar, with the network. In conjunction with the low proportion of plasticizer, this intimate connection is also maintained and there is no shrinkage on the circumference of the network, so that even over a long period of time, perfect contacting of the surrounding construction materials, especially when using the reinforcing elements as electrodes for dehumidification systems, is guaranteed is. The permanent contacting is additionally increased by the use of plastics doped with oxygen-reducing metals, since the passivation of the anode network is switched off.

A design according to claim 6 is also advantageous. The use of a plastic having semiconductor properties is distinguished by the fact that the charge transport by electrons and holes, in contrast to the so-called ion semiconductors, in which a mass transfer occurs with the charge transport port is connected. Above all, the conductivity in the temperature conditions occurring in building bodies is advantageous for the use of such reinforcing or supporting elements for building materials. Since the carbon components in these semiconductors do not have to form a skeleton in order to increase the conductivity, it is possible to find sufficiency with a low carbon component, as a result of which the fragility of such plastic coatings is reduced.

Another advantageous embodiment is described in claim 7. This makes it possible to adapt the reinforcement or support elements to their area of application, so that the mesh cannot be damaged when the construction materials are introduced.

An embodiment according to claim 8 is also advantageous, since this makes it easier to plaster in or incorporate the reinforcing elements into the building materials and allows them to be well adapted to the surfaces of the building bodies.

However, a further independent embodiment described in the preamble of claim 9 is also possible. This is defined by the features contained in the characterizing part of claim 9. By using electrodes of the same type, the disadvantages of electrolytic degradation due to potential differences existing in building structures can be avoided. In addition, it is possible to work with relatively low voltages when using the reinforcing elements as electrodes in so-called active electro-kinetic systems, since by using a counter-pole switching element, electrolytic deposits on the anode are avoided and therefore there is no passivation or insulation of the network connected to the positive pole.

However, training according to claim 10 is also possible. Such a circuit can be produced very easily in the different technologies, such as, for example, relay control, transistor control or with integrated switching modules, so that simple adaptation to the different applications and ambient conditions is possible.

Finally, the invention also includes an independent method according to the preamble of claim 11.

This method is defined by the characterizing features of claim 11. The feature of the larger positive time integral enables the desired electroosmotic effect, while the negative voltage eliminates any substances formed by electrolytic decomposition, in particular the unfavorable gases, in a reverse reaction. The high concentration of the substances produced on the electrodes results in a rapid and preferred reversal of the chemical processes, while the build-up of the reversed electric field and thus the reversal of the electroosmotic effect is reduced or completely prevented.

Further advantageous procedures are described in claims 12 and 13.

A procedure according to claim 14 is also advantageous. The voltage peak of the negative period can be cut off or only the part of the sine voltage exceeding a certain voltage can be used.

The advantage of the process lies not only in the increased desired effect, which leads to the desired success in a fraction of the time, even with very high water pressure with old and thick masonry, but also in the reliable avoidance of chemical decomposition of the water while preventing gas formation or separation of heavy metals, which in turn can lead to the destruction of building materials. The measured effective voltages of the positive portion of the AC voltage can be greater than 16 V. Electrodes made of conductive or semiconducting plastics are not attacked.

Finally, measures according to claim 15 are also possible. This advantageously enables the combination of a reinforcement or support element with the use as an electrode for a dehumidification system operating on the electroosmotic principle. Due to the sensible sequence of the individual process steps, an optimal result is achieved when using the reinforcement or support element.

For a better understanding of the invention, it is explained in more detail below with reference to the exemplary embodiments shown in the drawings.

• Fig. 1 eine Draufsicht auf einen netzförmigen Tragkörper, gemäss der Erfindung;
• Fig. 2 einen netzförmigen Tragkörper nach Figur 1 in schaubildlicher Darstellung, teilweise geschnitten;
• Fig. 3 einen Faden des Tragkörpers im Schnitt, gemäss den Linien 111-111 in Figur 2;
• Fig. 4 die Anordnung der erfindungsgemässen, netzförmigen Tragkörper bei gleichzeitiger Verwendung als Elektroden für ein Entfeuchtungssystem;
• Fig. 5 eine Ausführungsvariante einer auf elektroosmotischem Prinzip arbeitenden Elektro- Kinetik-Anlage, bei der der erfindungsgemässe netzförmige Tragkörper als Verstärkungs- bzw. Tragelement und gleichzeitig als Elektrode eingesetzt wird;
• Fig. 6 eine Spannungsversorgungsvorrichtung für die erfindungsgemässen Verstärkungs- bzw. Tragelemente, wenn diese als Elektroden für eine Elektro-Kinetik-Anlage verwendet werden.
• Fig. 7 eine Spannungszeitkurve für die zwischen positivem und negativem Potential wechselnde Spannung, wie sie an die Verstärkungs- bzw. Tragelemente angelegt werden kann, wenn diese als Elektroden einer Entfeuchtungsanlage verwendet werden.

Show it

• Figure 1 is a plan view of a net-shaped support body, according to the invention.
• 2 shows a reticulated support body according to FIG. 1 in a diagrammatic representation, partly in section;
• 3 shows a thread of the support body in section, according to lines 111-111 in FIG. 2;
• 4 shows the arrangement of the net-shaped support body according to the invention while simultaneously being used as electrodes for a dehumidification system;
• 5 shows an embodiment variant of an electro-kinetic system operating on the electroosmotic principle, in which the net-shaped support body according to the invention is used as a reinforcement or support element and at the same time as an electrode;
• Fig. 6 shows a voltage supply device for the reinforcement or support elements according to the invention when these are used as electrodes for an electro-kinetic system.
• 7 shows a voltage-time curve for the voltage alternating between positive and negative potential, as can be applied to the reinforcement or support elements when these are used as electrodes of a dehumidification system.

In Figure 1, a support body 1 is shown as a reinforcement or support element for the building serves fabrics. This support body 1 is designed as a network 2.

In the network 2, a power supply line 3 is integrated, which is formed by a conveyor belt 4. The power supply line 3 is arranged in the longitudinal direction - arrow 5 - of the band-shaped network 2 approximately centrally between the two longitudinal edges 6. The Lahnband 4 consists, as indicated over part of its length, from a plurality of individual strands 7, which are formed by metal threads 8. The surface of the metal threads 8 can be silver-coated, or e.g. Titanium wire is used to obtain a good conductivity and a small potential difference between the surface of these metal threads 8 and the plastic 9 surrounding them. If the potential difference is small, then an electromotive force can hardly develop between the different materials, such as silver or titanium, and the plastic 9 according to the invention, and therefore no current flows. However, this does not lead to metal degradation, especially of those metals that have a more negative intrinsic potential, so that no ions go into solution.

In Figure 2, a support body 10 is shown, which is formed by a network 11. The individual threads 12 to 14 of the network 11 consist of a plastic 15. This plastic 15 is essentially ion-free and is designed in the manner of a thermoset with a macromolecular structure. This plastic 15 is preferably e.g. an acrylate with at least partially crosslinked polymers, which has a high surface roughness and a low proportion of plasticizer. The plastic 15 can preferably be designed according to the Austrian patent specification 313 588 by the same inventor. It is advantageous if the plastic is doped with oxygen-reducing metals. When using a network 11 with a plastic 15 doped in this way as the anode, the oxidation of the anode and its passivation is switched off. In order to make the network correspondingly resistant to mechanical stresses or to increase the conductivity of the network threads, metal threads 16 or carbon threads 17 can be incorporated into these network threads. The metal or carbon threads 16 and 17 are incorporated in the plastic 15 of the threads 13 of the network.

The embodiment in FIG. 2 is further recommended if a power supply line 18 is formed by a thread 14 of the network. In this case, metal threads 16 or carbon threads 17, which can optionally be provided with a silver coating 19, are arranged in these mesh threads 14 to increase the conductivity, but also in addition to increase the mechanical strength. This silver coating achieves the advantages already described in connection with FIG. 1. Of course, it is also possible to provide the metal or carbon threads 16, 17 in the threads 13 with a silver coating in order to achieve the conductivity of the entire network, and thus an increased field structure over the entire network surface.

In the context of the invention, it is also possible to use any plastic 15 which is highly elastic, flexible or limp and conductive, in the manufacture of the network 11. In this case, the entire network is covered with the plastic 15 to produce the desired surface quality of the network 11, as is indicated in the region of the crossing threads 12 and 14 of the network 11.

The carbon or metal threads 17 or 16, regardless of their function with regard to improved electrical properties, such as higher conductivity and the like, form a strength-enhancing, thread-like carrier material 20. The carrier material 20 can of course be formed by threads made of any materials that However, metal threads are preferably used because they have a good combination of high strength and good conductivity within the scope of the desired properties according to the invention.

FIG. 3 shows a section through a thread 13 of the net 11 on an enlarged scale. As can be seen, 13 metal threads 16 or carbon threads 17 are embedded in the plastic 15 of the thread, some of which are provided with a silver coating 19. Furthermore, it can be seen from this section that carbon components 21 are freely suspended in the plastic 15. This free-floating arrangement of carbon components 21 is possible because the plastic 15 has semiconductor properties and the carbon is therefore not required to build up a line system, but only to increase the conductivity.

FIGS. 4 and 5 show two different design variants of how the support body 1 or nets 2 or 11 according to the invention can be arranged on structures 22 and 23, respectively. The building structure 22 or 23 consists, for example, of brick masonry or reinforced concrete in the exemplary embodiments shown.

In the embodiment according to FIG. 4, two nets 24 and 25 are fastened to the building structure 22 by means of fastening means 27 consisting of resistant materials 26, for example plastic clamping plugs. After the network 24 is connected to the positive pole 28 and the network 25 to the negative pole 29 of a DC voltage source 30 of a voltage supply device 31, the networks 24 and 25 are embedded in a building material 32, in the present case a plastering mortar 33. The plastering mortar 33 is applied in such a thickness that the nets 24 and 25 come to lie below its outside 34. The nets 24 and 25 thus form an anode 35 and a cathode 36 of an electro-kinetic system 37. In order to prevent an effective horizontal barrier against the rising of moisture 38, which is contained in the foundation area of the structure 22, the two are Nets 24 and 25 in the vertical direction one above the other on the outside of the structure arranged. The grid 25 forming the cathode 36 is arranged in the bottom 39, with a change of the floor advantageously taking place in the area of the net 25, so that porous, highly water-draining layers are arranged in the area of the net. In the application form of the support body according to the invention shown in FIG. 5 - in the description of which the same reference numbers are used as in FIG. 4 for the same parts - the net 24 forming the anode 35 on the inside of the building is due to a thickness 40 of the structure 23 facing side of the structure 23 and the grid 25 forming the cathode 36 attached to the outside thereof.

As in the exemplary embodiment according to FIG. 4, the network 25 is again arranged in the region of the bottom 39 and when the two networks 24, 25 are applied to the DC voltage source 30, an intense electrical field 41 is created, which is indicated schematically by field lines 42.

Due to the arrangement of the anode above the cathode, the moisture migrates within the structure 23 in the direction of the cathode or the moisture 38 rising in the foundation is prevented from rising in the structure 23. This dehumidification or drying effect is symbolically indicated by arrows 43 in FIGS. 4 and 5 in both exemplary embodiments. The field structure between the networks 24 and 25 in FIG. 4 is also symbolically indicated by field lines 42.

In order to avoid depolarization of the anode and thus a weakening of the conductivity and a reduction in the field strength regardless of or in addition to the doping of the plastic, the DC voltage source 30 is assigned a counter-pole switching element 44. This opposite pole switching element 44 has the effect that the polarity in the electro-kinetic system 37 is periodically and briefly reversed. As a result, the ions in the electric field cannot be deposited and depolarization is avoided. The high conductivity achieved in this way in the building structure 22 or 23 prevents the salt ions migrating between the networks 24 and 25 from depositing and blooming. Due to the high conductivity, a high current passage in the structure 22 or 23 is also achieved, so that a very intensive field is built up, which causes an intensive water transport in the direction of the cathode.

Of course, it is also possible to arrange the networks 2, 11, 24, 25 according to the invention in two different high positions relative to the floor 39 and to short-circuit them, i.e. i.e. to connect, which balances out the natural potential difference and creates a so-called horizontal barrier, which prevents the water from migrating up through the built-in networks.

The advantage of using the networks according to the invention as a reinforcing or supporting element for building materials is, above all, that the special plastic used, due to the high surface roughness and the low shrinkage, ensures an intimate connection between the building material and the reinforcing element over a long period of time , whereby moisture accumulations in the area of the reinforcing elements and thus subsequent corrosion are switched off and a high electrical conductivity of the system is achieved when using the network as electrodes.

FIG. 6 shows a voltage supply device 45 for the networks 48, 49 designed according to the invention, which form an anode 46 or a cathode 47. The voltage supply device comprises a transformer 50, smoothing diodes 51, an opposing pole switching element 52 and a timing element 53. The opposing pole switching element 52 has a pulse switch 55 which is arranged in parallel with the smoothing diodes 51 of a rectifier circuit 54 and is formed by a transistor 56. The signal passage through the transistor 56 is made possible for a certain period of time via the timing element 53. The diode 57 assigned to the opposite pole switching element 52 ensures that a voltage passage is only possible if a negative potential is present at an output 58 of the transformer 50. An input 59 of the pulse switch 55 is present at the output 58 of a DC voltage source 60 formed by the transformer 50. An output 61 is connected to a lead 62 to the anode 46. The transistor 56 serving as a make contact is driven by the timing element 53. Between the supply line 62 and a supply line 64 and the anode 46 or the cathode 47, a changeover switch 65 is also provided, with which the voltage supply of the two networks 48 and 49 can be reversed, if necessary, so that the anode acts as a cathode or vice versa. Furthermore, a current display device 66 is assigned to the voltage supply device 45. Of course, the design of this voltage supply device can be modified as desired within the scope of the invention without deviating from it, and it is also possible to use corresponding relay controls or integrated circuits or microprocessors or the like instead of the transistor circuit shown.

A preferred form of the voltage-time curve is shown in FIG. The positive sine curve 67 of a correspondingly stepped down mains voltage is preserved, while the negative part 68 of the sine curve is cut off in the lower voltage range, so that as long as the negative part of the original sine curve does not exceed a certain voltage, no voltage is present and only when the sine voltage reaches the predetermined one Voltage limit is exceeded, the voltage exceeding this voltage limit is applied to the electrodes.

Although the use of the mains frequency offers particular advantages, the method according to the invention is not restricted to sinusoidal voltages of 50 or 60 _S - ¹ .

This preferred form of the voltage-time curve can, for example, with the voltage supply device described in Figure 6 45 can be achieved. Through the capacitor arranged in the timing element 53, the passage through the transistor 56 is only opened after the positive potential has been present for a certain period of time, so that the anode 46 is subjected to a negative voltage. With a corresponding design of the timing element 53, the supply of the negative voltage via the lead 62 through the transistor 56 is then blocked again when the preselected voltage level is undershot. This creates the special voltage curve shown in FIG. 7.

It is advantageous for the present invention when using the reinforcement or support elements according to the invention as electrodes if their minimum distance in the vertical direction of the structure is at least 10 cm. The network forming the cathode is preferably to be arranged approximately 30 to 50 cm below the surface of the ground. For the method according to the invention in connection with the voltage supply device 45, it is of crucial importance that the load integral is set at any point on the electrodes with regard to the voltage or the current intensity in such a way that the production of aggressive oxygen is negligibly small or only in one Order of magnitude moved by which the reinforcement or support elements can not be destroyed.

Claims (15)

1. Reinforcing or carrier element for structural materials, constructed as an electrode for electro- osmotic dehumidification installations, with a net-like carrier body, comprising a conductive synthetic resin at least on its surface, characterised in that the net-like carrier body (1, 10) is an essentially band-shaped net (2, 11, 24, 25, 48, 49) constituted by flexible net strands which is made of synthetic resin and/or coated therewith, and a current supply conductor (3) is connected to the net and extends in the longitudinal direction of the carrier body or band-shaped net (2, 11, 24, 25, 48, 49) and is in contact therewith, which conductor comprises filamentary carrier materials (20) and is also connected to a positive pole (28) of a voltage supply circuit (31, 45) for an electrokinetic installation (37), and in that the net forms an anode.

2. Reinforcing or carrier element according to claim 1, characterised in that the current supply conductor (3) is formed by flattened bands (4) constituted by a plurality of flexible individual strands (7).

3. Reinforcing or carrier element according to one of claims 1 or 2 characterised in that the current supply conductor (3) is formed by carbon filaments (17) or metal filaments (8, 16) for example of titanium or the like, incorporated in the net strands and advantageously silver-coated.

4. Reinforcing or carrier element according to one of claims 1 to 3, characterised in that the electric power supply conductor (3) is disposed approximately centrally between the longitudinal edges (6) of the net.

5. Reinforcing or carrier element according to one of claims 1 to 4, characterised in that the conductive synthetic resin of the electric power supply conductor (3) and/or the net (2, 11, 24, 25, 48, 49) is a substantially ion-free synthetic resin of the thermosetting type with a macromolecular structure, for example an acrylate, with polymers at least partially crosslinked, and has a high surface roughness and a small proportion of plasticiser, and is advantageously doped with an oxygen-reducing metal, for example titanium or boron.

6. Reinforcing or carrier element according to one of claims 1 to 5, characterised in that the synthetic resin (9, 15) surrounding the current supply conductor and the filamentary carrier material (20) has semiconductor properties and a relatively small proportion of carbon, the carbon components (21) being disposed so as to be freely floating in the synthetic resin (9, 15).

7. Reinforcing or carrier element according to one of claims 1 to 6, characterised in that the mesh size is adapted to the structural material (32) surrounding the net (2, 11, 24, 25, 48, 49) and advantageously comprises a mesh size of 5 mm when used as a plaster carrier.

8. Reinforcing or carrier element according to one of claims 1 to 7, characterised in that the net (2, 11, 24, 25, 48, 49) is constructed to be elastic and shape-retaining, and more particularly is of a flexible synthetic resin (9, 15).

9. Reinforcing or carrier element for structural materials, constructed as an electrode for electro- osmotic dehumidification installations, with a net-like carrier body, comprising a conductive synthetic resin at least on its surface, in particular according to one of claims 1 to 8, characterised in that the carrier body (1, 10) is realised as a flexible net (2, 11, 24, 25, 48, 49) which is made of a conductive synthetic resin and/or coated therewith and with which filamentary carrier materials (20) are associated, and in that the net (2, 11, 24, 25, 48, 49) forms a cathode (36, 47) and/or an anode (35, 46) of a voltage supply circuit (31, 45) for an electrokinetic installation (37) and in that the two nets (2, 11, 24, 25, 48, 49) are disposed one above the other in a vertical direction, such that the net (2,11, 25, 49) nearer the ground (39) is connected to the negative pole (29) of a direct current voltage source (30, 60) and the other net (2, 11, 24, 48) is connected to a positive pole (28), and in that a polarity reversal switching member (44, 52) is disposed between the net (2, 11, 24, 48) in contact with the positive pole (28) and the direct current voltage source (30, 60).

10. Reinforcing or carrier element according to claim 9, characterised in that the polarity reversal switching member (44, 52) comprises a pulse switch (55) disposed parallel to stabilizing diodes (51) of a rectifier circuit (54), one input of the switch being connected to the negative pole (29) of a direct current source (30, 60) and its output (61) to a connecting lead (62) to the anode (35, 46), such that a closing contact (63) of the pulse switch (55) is actuated using a timing member (53).

11. A method for the electro-osomotic movement of polar liquids in porous materials (masonry or the like) by supplying an electrical voltage between electrodes, using net-like carrier bodies of a reinforcing or carrier element for structural materials, in particular according to one of claims 1 to 10, characterised in that the carrier body formed as a flexible net is made of a conductive synthetic resin and/or coated therewith and filamentary carrier materials are associated with the latter, and in that two carrier bodies are disposed one above the other in the vertical direction of the structural material, and in that the voltage supplied to them is a voltage alternating between a positive and a negative potential, where the time integral of the voltage with a positive potential exceeds that of the voltage with a negative potential, whereby the voltage with a positive potential advantageously exceeds that with a negative potential.

12. A method according to claim 11, characterised in that the time interval of the voltage supplied with a positive potential exceeds that with a negative potential.

13. A method according to either one of claims 11 or 12, characterised in that the alternating voltage is a sine voltage of mains frequency, such that the voltage of the negative cycle is reduced, and more particularly the voltage peak of the negative cycle is chopped.

14. A method according to claim 13, characterised in that in the negative cycle only the portion (68) of the sine voltage exceeding a predetermined voltage is supplied, and advantageously the sine voltage (67) of the positive half-wave exceeds 6 volts.

15. A method according to one of claims 11 to 14, characterised in that the net (2, 11, 24, 25, 48, 49) is connected to a structural body (22) by chemically or electrochemically resistant materials (26) and subsequently a structural material (32), in particular plaster (33) is applied to the net (2, 11, 24, 25, 48, 49) and is embedded between the external surface (34) of the structural material (32) and the structural body (22), after which the net (2, 11, 24, 25, 48, 49) is connected to the direct current source (30, 60) via the polarity reversal switching member (44, 52) and is actuated by the voltage alternating between a positive and a negative potential.

Images