EP4031727A1

EP4031727A1 - Controlling electrical bias for facilitating striking of a reinforced-concrete wall

Info

Publication number: EP4031727A1
Application number: EP20820261.4A
Authority: EP
Inventors: Sylvain Lefeuvre
Original assignee: Outinord St Amand SA
Current assignee: Outinord St Amand SA
Priority date: 2019-09-20
Filing date: 2020-09-18
Publication date: 2022-07-27
Also published as: WO2021053303A1; FR3101090B1; FR3101090A1

Abstract

The method for controlling electrical bias facilitating striking of a reinforced-concrete wall from the electrically conductive formwork face of a formwork panel forming part of formwork defining a formwork space, when a metal frame has been arranged in this space and chosen regular concrete, suitable for electrical bias and batched beforehand, has been poured therein and compacted at the time T1, by applying an electrical potential difference ΔV between the formwork face and the frame, such that: for the chosen concrete, the time ΔTa between the batching time T0 and the theoretical time T2 of the onset of setting of the concrete is available, and the start of the application of the electrical potential difference ΔV is commanded at a time T3 that is after the time T1 by a delay ΔTc equal to (T0 – T1) + (ΔTa – ΔTb), wherein ΔTb is a duration of anticipation of the onset of setting of the concrete.

Description

CONTROL OF THE ELECTRIC POLARIZATION TO FACILITATE THE DECOFFRING OF A

REINFORCED CONCRETE WALL

The field of the invention is, most widely considered, the use of concrete with a view to producing a reinforced concrete wall, more particularly, the stripping of such a wall with electrical polarization to facilitate stripping (hereinafter sometimes referred to as "electrical polarization" or "polarization" by ellipse), and more specifically, polarization control.

A reinforced concrete wall (hereinafter sometimes referred to, by ellipse, "wall" or "concrete wall") is a structure or part of a structure for building, civil engineering or public works, the achievements and forms of which can be various, such as a partition, a wall, a shear, a vertical wall or a post, or even a floor. The concrete is either delivered to the job site fresh by a producer or manufactured on the job site by the user. The concrete is poured either in situ or on a prefabrication site or in the factory, in a formwork space delimited by a formwork comprising at least formwork panel (as will be explained later) having a formwork face (or skin), then that a mechanical resistance reinforcement has been placed in the formwork space in an adequate manner so as to be ultimately - and for the most part at least - embedded in the concrete. In a number of usual cases, the formwork has two formwork, so that the formwork space can then be qualified as an interbank space, and the formwork faces, in situation, are kept stable vertically parallel to each other. and separated by leaving between them the interbank space. In another case, the formwork includes only one panel, in the lower horizontal position and there is no panel above the wall to be cast. It should be noted that the proposed process can be applied to any type of formwork with reinforcement. In addition, the process can be applied on the final site or in a factory for the prefabrication of concrete elements.

The stripping of such a concrete wall is, in the strict sense, the operation which consists in separating the formwork (in particular the formwork or the two formwork) from the wall, once the concrete has been poured into the formwork space (in particular the interbank space) is sufficiently hardened, and consequently to remove the formwork. After such stripping, the wall, stripped, has at least one face - the facing - which may remain visible untreated or subsequently be the subject of mechanical and / or chemical treatments, while the wall (s) , released, can be moved, stored or reused. It will be explained below that it is recommended to plan an operation to facilitate the stripping.

Concrete is made from cement, mixing water, aggregates (such as sand and gravel), and, where appropriate as needed, one or more additives (such as in particular a plasticizer, a plasticizer, a setting retarder or a setting accelerator) and / or additives (such as in particular fibers and pigments). The standards classify so-called "common" cements into five main types called CMI, CM II, OMNI, CMIV and CMV (CMI and CMII type cements themselves comprising several kinds of Portland cements, each having its own notation as CEM I , CEM ll / AS ...), each type and / or kind of cement being characterized by its main constituents and a resistance class which must be in line with the envisaged application and the expected requirements. Where appropriate, the concrete can be self-consolidating.

By mixing and mixing the constituents of the concrete, the anhydrous cement is hydrated with the mixing water and the cement paste is gradually stiffened and hardened. Once the mixing and kneading have been carried out and as long as the hydration is not too advanced, the concrete, then qualified as "fresh", is openable, in particular malleable or plastic, can be poured and compacted, and suitable for filling a formwork space (in particular the interbank space) and to suitably embed and embed the mechanical resistance reinforcement. Intervenes later (at the end of a phase sometimes qualified as "dormant"), often after 1 hour and a half to more than two hours after the first contact of water and cement (called here the mixing or the mixing) for most common cements, the start of setting of the concrete: the concrete loses the workability that it had previously, it becomes more rigid, there is release of heat. It is known that the start of the setting of the concrete can be determined scientifically by using a “Vicat needle” capable of being driven into the concrete. Subsequently, the start of hardening (maturation) of the concrete takes place, which will continue over time, the concrete, first said to be "young", being qualified as "hardened" after several weeks, its resistance to 28 days being the conventional value. considered classically. During the process, the physico-chemical properties of concrete change. Thus and in particular, its internal temperature tends to increase when the chemical reactions of which it is the object are exothermic, the water content decreases, and most often, its electrical conductivity varies first by increasing then by decreasing at the beginning of the process. solidification.

Depending on the required properties of the fresh concrete and the hardened concrete, the specific features of the wall to be made, the conditions for its realization and its implementation (in particular thanks to the Dreux chart), the envisaged application and the expected requirements, a person skilled in the art is able to know what the combination of the qualitative and quantitative composition parameters of the concrete to be used (concrete formulation) is.

The field of application of the invention is concretes qualified as “ordinary concrete”, heavy, light or of normal density, manufactured on site, ready for use or produced in a factory for the manufacture of prefabricated products and brought to the site. site, compacted, in such a way that the quantity of occluded air other than the entrained air is negligible, as provided for in standards NF DTU 21 and NF EN 206-1 and which, moreover, are suitable for polarization electric.

A reinforcement for reinforced concrete (also called reinforcement) has the function of reinforcing the mechanical resistance of the wall. It is made of a suitable steel and comes in the form of bars, trellises or cages. It is arranged and maintained within the formwork space (in particular the interbank space) longitudinally and transversely, or in other words, in the vertical direction and in the horizontal direction (the form (s) being in position). The structure of a reinforcement, its characteristics, its arrangement (positioning, anchoring and maintenance in the shuttering space, in particular the interbank space) are within the reach of those skilled in the art, as are the means capable of enabling the continuity of the structure. reinforcement between adjacent wall elements. For this purpose, it is then expected that the reinforcement has one (or more) protruding and emergent ends not embedded in the concrete (sometimes called splicing parts). The metal frame conducts electricity. On its surface there may be a layer of scale from manufacturing, an oxidation layer from storage, or there may be passivation or corrosion reactions.

A shuttering is essentially a prefabricated shuttering panel capable of being reused, which comprises a framework, a shuttering face intended to be in contact with the concrete for the realization of the wall, which is a face of a formwork structure (wall , coating, etc.), and additional equipment, such as, in particular, devices for maintaining, adjusting, stabilizing, gripping, working, access, in particular in the upper part, and protection. The term blank used here, for convenience of language, should be understood as referring to a shuttering element for a concrete wall, essentially comprising a framework and a shuttering face which is a face of a shuttering structure, capable of being held in position at the desired location and cash forces arising from the presence of concrete in the formwork space. The formwork face can be kept in a vertical or horizontal position according to the various cases already mentioned.

According to the embodiments, the sheet, and in particular its formwork face, is made of wood, metal or mixed. In many cases where it is a question of making a partition or a wall having two facings, the formwork is used in pairs, two facing formwork being coupled, and it can be associated with one or more ends specific to transversely close the interbank space at one or / and the other of the two ends. It is also possible to use only one panel, and not two, if there is already a wall bounded by concrete, the ground, or otherwise, located opposite the single panel often called closing panel or else for example for the formwork of a floor. It is also possible to use more than two formwork, for example to make a column with a triangular or more generally polygonal cross section.

The field of application of the invention is formwork as defined above, having an electrically conductive formwork face, such as a metal formwork face, in particular made of steel, or made electrically conductive if it is not. was not originally. The forms can be the subject of various embodiments and improvements, as illustrated in particular and without limitation by documents FR 3035134, FR 3042807 and FR 3074205. They can be of variable dimensions, in height, from 1 m to 3 m, and in width. A classic panel for the construction of a wall or a room partition can have a height adapted to that of the room, ranging from approximately 2.50 m to 2.80 m and a length (in horizontal direction), ranging from 1.25 m to 2.50 m approximately. A section may have a shorter length, if necessary. In the case of a pair of formwork, the formwork faces are kept apart from the thickness of the wall to be produced, which may vary according to requirements, typically between 12 cm and 25 cm approximately, according to the rules of the art , by means of spacers. The appearance of the formwork face conditions that of the raw cladding of the concrete wall.

Depending on requirements, the shutters are often straight, and it can be planned to rigidly associate two shutters or two pairs of shutters (or more) side by side or else a panel with a sub-rise arranged and fixed below and / or an extension arranged and fixed above, the height of which, adapted to the needs, can range from approximately 0.25 m to 1.50 m, these values being given only by way of example. Such rigid associations are made by means of bolts, projections, notches, etc., as described for example in document FR 2969195. There is then physical continuity between the adjoining formwork faces, downwards, upwards or towards one or the other of the lateral sides. Curved or rounded formwork also fall within the present scope of the present invention.

To make a reinforced concrete wall shuttering, in the case where a pair of shutterings is used, this pair of shutters and concrete prepared in a mixer, fresh and maintained in a fluid state, in particular as in a top mounted on a truck. Depending on the case, it is concrete "with specified properties" or concrete "with prescribed composition". The two shutters are then installed, in particular in situ at the desired location, and they are held in a fixed and suitable manner with the required spacing between, on the one hand, the formwork faces, and, on the other hand, between the formwork faces and the reinforcement placed in the interbank space, if necessary with one or more sub-risers and / or risers. Then, the concrete is poured in the fluid state in the interbank space, ensuring that it is suitably compacted and correctly fills the interbank space. Then, we wait for the concrete to set and we let the concrete set. Finally, the formwork is separated from the wall produced (stripping operation). To maintain the required spacing between the formwork faces of two opposite forms, it is known to use spacers forming spacers fixed to the two forms and passing through the interbank space.

Most often, the reinforcement protrudes above the interbank space, leaving its upper end section accessible and not encased in concrete or embedded in concrete, at this stage of the construction. Sometimes it is another end section that is accessible and not encased or embedded in concrete.

Fresh concrete is poured into the interbank space by gravity (by limiting the drop height) and, in a particular embodiment, it is vibrated in successive layers according to the rules of the art, for an appropriate time so that its components s '' organize properly, that the concrete is compacted properly, that the interbank space is optimally filled with concrete, and that the air contained in the concrete is evacuated, all this contributing to the quality of the hardened concrete. For this purpose, it is known, in one embodiment, to use vibration means providing either an internal vibration in the concrete, the vibration means (such as vibrating needles or pervibrators) acting within the concrete itself or, in some cases, an external vibration. In another embodiment, a self-consolidating concrete is used, which eliminates the vibration.

The setting and hardening of the concrete depend on the temperature of the fresh concrete and the climatic conditions, in particular the ambient temperature. Setting and curing occurs earlier and is faster with high ambient temperatures and occurs later and is slower with low ambient temperatures. This is why the standards provide that concreting is only carried out when the ambient temperature is between -5Ό and + 40Ό, an ambient temperature in the range + 5 ° C / + 32 Ό being preferable. When the ambient temperature is near the extreme limits, concreting can optionally be considered if necessary, in particular by adapting the formulation of the concrete.

The stripping of the shuttering reinforced concrete wall can only take place when its resistance is sufficient, which is conditioned by a number of factors, in particular but not limited to, the formulation of the concrete, the nature and characteristics of the wall, the desired facing. , Room temperature. In average climatic conditions where the ambient temperature is between 10Ό and 25 ° C, form stripping can take place, depending on the circumstances, usually between 12 hours to 24 hours after the concrete has been poured, its compaction ensured. , or after a longer delay.

Depending on the applications envisaged and the expected requirements, the facings of the wall have a quality which can be of elementary level, or else ordinary, the method proposed here making it possible to obtain the expected quality for the facing.

In the art, it is sought to easily demould formwork (including formwork), with minimal residual adhesion and without damaging the concrete wall formed, in particular without damaging its facing. In the case of formwork or shuttering with multiple uses, it is also sought to protect the formwork face of the shuttering / formwork as well as possible.

According to an extremely widespread practice on construction sites, a formwork release oil is applied before pouring on the formwork faces. The document entitled “Concrete release products”, of Technical Aide-Mémoire ED 6017 from the National Research and Safety Institute - INRS -, dated July 2007) gives recommendations on the selection and setting. use of these mold release agents (aforementioned oil or other release material). Application of mold release oil involves a tedious operation. This operation also involves health risks for the people who carry it out and risks for the environment because part of the oil can spill out and reach the sewers.

In addition, the application of oil / mold release agent results in accidentally depositing or splashing release agent on the reinforcement, which is detrimental to subsequent intimate contact between the poured concrete and the reinforcement.

It is therefore understandable that a solution making it possible to do without a form stripping agent is of great interest.

A principle of electrical polarization of concrete has already been proposed, in particular in document FR2948711. An electric field applied between the reinforcement and the formwork face allows water to migrate towards the formwork face. A water film formed on the formwork face surface decreases adhesion and the presence of this water film facilitates form stripping. A sensor embedded in the poured concrete is used to determine the moment and duration of application of the electrical polarization, which increases the cost of the process and proves to be very impractical to implement on most construction sites in real conditions. .

The Elsevier article ISSN 0950-0618 of January 2014 (ref XP028623334) and the thesis of N Goudjil of January 2012 (ref XP055711559) also teach these elements.

However, there remains a need to propose a solution that can be applied in practice on construction sites, far from the laboratory context.

Disclosure of the invention

The problem underlying the invention is to make a reinforced concrete wall with shuttering by means of an electrical polarization with processes, devices and systems optimized for use on construction sites.

According to a first aspect, the invention relates to a method of controlling the electrical polarization facilitating the stripping of a reinforced concrete wall, for a formwork having an electrically conductive formwork face and delimiting a formwork space, whereas '' a metal reinforcement was placed in the formwork space and that the current concrete chosen suitable for electrical polarization, was previously mixed, then was poured into the formwork space and compacted, the electrical polarization being carried out by application, before the start of setting of the concrete, a difference in electrical potential of voltage AV between the formwork face and the reinforcement, in which we have, for the chosen concrete, the duration ATa between the moment of mixing and the moment theoretical T2 of the beginning of the setting of the concrete.

In addition, the proposed method is that the effective moment of the batch is noted T0, (whether this moment is identified, or estimated, or provided), the moment when the compaction is ensured is noted T1, and the start of l is ordered. 'application of the difference in electric potential to a time T3 temporally delayed from time T1 by a delay ATc defined by the equation ATc = (ATa - ATb) + (TO - T1), in which ATb is an anticipation duration desired in relation to the moment T2 of the start of the concrete setting.

Advantageously, this process allows water to migrate towards the formwork face. A film of water thus forms between the formwork face and the concrete. This facilitates formwork stripping at the desired time when the concrete has set sufficient.

Moreover, thanks to the knowledge of the moments TO and T1, of relatively easy access under site conditions, and thanks to a judicious calculation carried out by means of the equation proposed above, it is possible to start the electrical polarization at the most opportune moment before the start of setting of the concrete, T2 being in the future compared to the start of the polarization T3.

Note that there is no need to insert any sensor into the concrete to implement the proposed process, which makes the process economically viable and relevant.

It is noted here that the start of polarization is anticipated with respect to the start of setting of the concrete, but also as will be seen below, the end of this polarization preferably occurs before the start of setting of the concrete. However, it is not excluded to have other subsequent polarization sequences, after a first phase of concrete setting, as will be seen below.

TO can be the actual spotted moment of the waste or the estimated or supplied moment of the waste.

ATb can be chosen between 0 and 145 minutes, more particularly between 15 minutes and 60 minutes, more especially between 15 minutes and 25 minutes,

ATb can be either a fixed or adjustable value, the control method then comprising an operation of adjusting ATb.

According to one embodiment, the ambient temperature Ture is determined, a means of supplying ATa / Ture data is available, such as an abacus, which for the selected concrete, gives the duration ATa as a function of the ambient temperature Ture, and one determines the duration ATa from the data supply means ATa / Ture. Thus, the duration ATa taken into account effectively corresponds to that of the chosen concrete, and more corrected for the effect of the actual temperature environment.

According to one embodiment, the ambient temperature Ture is determined, a means of supplying AV / Ture data is available, such as an abacus, which, for the chosen concrete, gives the potential difference AV to be applied as a function of the ambient temperature Ture , and determining the AV potential difference to be applied from the AV / Ture data supplying means. Thus, the potential difference AV taken into account effectively corresponds to that recommended for the chosen concrete, and more corrected for the effect of the actual temperature environment.

The ambient temperature Ture taken into account, as regards the means of supplying ATa / Ture and / or AV / Ture data, Ture can be the actual ambient temperature measured on the site. Ture can also be the ambient temperature estimated from data available on weather websites on the Internet. Ture can be provided by sensors near the site.

According to one embodiment, the moment T1 is detected, either automatically with a means associated with the formwork space or non-automatically, and the start of the application of the potential difference AV is automatically controlled at the moment T3 = T1 + ATc.

According to one embodiment, the end of the application of the potential difference AV is ordered at a moment T4 which follows the moment T3 with a polarization duration ATd, chosen to be between 10 minutes and 60 minutes, more particularly between 5 minutes and 30 minutes. minutes, especially between 10 minutes and 20 minutes.

According to one embodiment, ATb and ATd are chosen so that the moment T4 is prior to the moment of the start of setting of the concrete T2.

ATd is either a fixed or configurable value. When the duration ATd can be parameterized, the method comprises an operation of determining ATd, in particular as a function of the ambient temperature Ture, so that, all other things being equal and relative to a predetermined average ambient temperature, ATd is reduced if the Ture ambient temperature is greater than the predetermined average ambient temperature and ATd is increased if the ambient temperature Ture is smaller than the predetermined average ambient temperature.

The predetermined average ambient temperature can be derived from previous meteorological data or be derived from a sliding average over the previous days with extrapolation. Note that this average temperature is a rather theoretical data, while the ambient temperature Ture is a real data corresponding to a capture on the site or nearby.

According to one option, it may be provided, after an initial polarization sequence (SQO) starting at time T3 and ending at time T4, one or more subsequent polarization sequences. This allows, over a temporal logic of several hours, to make polarization reminders (of short duration) which maintain the presence of the water film at the interface between the formwork face and the concrete being set. These short-term recalls are considered almost "one-off" and do not consume much electrical power.

According to this option, it can also be provided that, for said subsequent polarization sequences, the polarization voltage (s) (AVA1, AVA2, AVA3) are higher than the polarization voltage of the initial polarization sequence. This allows, by means of the progressive state of progress of the setting of the concrete, to still generate a migration of water towards the formwork face, in spite of an upper resistance to the movements of the water molecules.

According to one embodiment, the method comprises:

- at least one security and control operation, such as:

- verification of the absence of an electrical short-circuit, or galvanic isolation, between the reinforcement and the formwork face,

- verification of the presence of concrete in the formwork space, in particular the presence of concrete at the desired level,

- verification of the failure to exceed an upper threshold and / or a lower ambient temperature threshold Ture,

- check that DTo has a positive value,

- and, in the event of an indication of a malfunction, an information, alert or shutdown operation.

According to one embodiment, the method comprises:

- at least one data or parameter storage operation from the selected concrete, TO, T1, T2, T3, T4, ATa, ATb, DTo, ATd, AV, Ture, and / or indication of malfunction,

- and / or at least one data transmission or communication operation, parameter, indication of malfunction,

- and / or at least one data printing operation, parameter, indication of malfunction.

According to one embodiment, an electrical energy source is provided, having a positive terminal and a negative terminal, to apply the electrical polarization between, on the one hand, the formwork face (s) connected to the negative terminal and on the other hand the armature connected to the positive terminal.

According to one embodiment, the proposed method is applied to the stripping of a shuttering reinforced concrete wall with two formwork faces electrically conductive of a pair of shutterings defining an interbank formwork space.

According to other embodiments, the proposed method can be applied to any type of formwork, namely a horizontal formwork for a floor, a formwork for a tunnel, a formwork with a single form, a formwork with more than two formwork. According to a second aspect, the subject of the invention is a control device for implementing the control method which has been described.

According to one embodiment, the electrical polarization control device facilitating the stripping of a reinforced concrete wall for a formwork having an electrically conductive formwork face and delimiting a formwork space, while a metal frame has been placed. in the formwork space and that the current concrete chosen suitable for electrical polarization, wasted at time TO, was poured into the formwork space and its compaction ensured at time T1, by application of a difference in electrical potential of polarization AV between the formwork face and the reinforcement, with an electric power source having a positive terminal and a negative terminal, to apply the electric polarization, an electric connection means for the formwork face and an electric connection means for the reinforcement, so that the formwork face (s) is (are) connected to the negative terminal and the reinforcement is connected to the positive terminal, the control device comprising:

- a means providing, for the chosen concrete, the duration ATa between the moment TO of the mixture and the theoretical moment T2 of the start of setting of the concrete,

a means for controlling the start of the application of the potential difference AV, at a time T3 which follows the time T1 with a delay ATc equal to (TO - T1) + (ATa-ATb), in which ATb is a desired anticipation time in relation to the moment T2 of the start of setting of the concrete.

According to one embodiment, there is provided a means for locating the moment TO, or a means for entering the estimated or supplied moment TO, associated with the means for controlling the start of the application of the potential difference AV.

According to one embodiment, a means for adjusting ATb is provided, associated with the means for controlling the start of the application of the potential difference AV.

According to one embodiment, a means is provided for determining the ambient temperature Ture and a means for supplying ATa / Ture data, such as an abacus, which for the chosen concrete, gives the duration ATa as a function of the ambient temperature Ture, associated by controlling the start of the application of the potential difference AV.

According to one embodiment, a means is provided for determining the ambient temperature Ture and a means for supplying AV / Ture data, such as an abacus, which, for the chosen concrete, gives the potential difference AV to be applied as a function of the temperature. ambient Ture, associated with the control means for the start of the application of the potential difference AV.

According to the embodiments, a means is provided for measuring the Ture ambient temperature or for entering the estimated or supplied Ture ambient temperature, associated with the means for controlling the start of the application of the potential difference AV.

According to one embodiment, a means for automatically detecting the moment T1 is provided, associated with the formwork space and with a means for automatically controlling the start of the application of the potential difference AV at the moment T1 + ATc.

According to one embodiment, a means is provided for controlling the end of the application of the potential difference AV at a time T4 which follows the time T3 with a bias delay ATd.

According to one embodiment, a means of setting the delay ATd is provided.

According to the embodiments, at least one security and control means is provided, such as: - a means of verifying the absence of an electrical short-circuit, or galvanic isolation, between the reinforcement and the formwork face,

- a means of verifying the presence of concrete in the formwork space, in particular the presence of concrete at the desired level,

- a means of verifying that an upper threshold and / or a lower ambient temperature threshold Ture has not been exceeded,

- a means of checking that ATc has a positive value.

According to the achievements, it is planned, associated with the means of security and control, a means of information, alert, or shutdown.

According to the embodiments, at least one data or parameter storage means is provided from among the concrete chosen, TO, T1, T2, T3, T4, ATa, ATb, DTo, ATd, AV, Ture, and / or indication of malfunction , and / or at least one means of transmission or communication of data, parameter, indication of malfunction, and / or at least one means of printing data, parameter, indication of malfunction.

According to the embodiments, the potential difference AV is chosen to be between 0.2 volts and 12 volts, more particularly between 0.5 volts and 6 volts, more especially between 1 volts and 3 volts.

According to the embodiments, AV is either a fixed or adjustable value, the electrical polarization method then comprising an operation of adjusting AV, in particular as a function of the ambient temperature Ture.

According to another aspect, the subject of the invention is a method for stripping a shuttering reinforced concrete wall and a shuttering face of a shuttering forming part of a shuttering delimiting a shuttering space, characterized in that it includes an electrical polarization facilitating the stripping by the method which has been described.

According to another aspect, the subject of the invention is a process for producing a reinforced concrete wall stripped shutter with electrical polarization, in which:

- a formwork delimiting a formwork space and comprising a shuttering having an electrically conductive formwork face is available,

- we have available the selected current concrete suitable for electrical polarization,

- a metal frame is placed in the formwork space,

- the formwork space is filled with concrete, its compaction being ensured,

- and with the control method which has been described, an electrical polarization is controlled, by applying an electrical potential difference AV between the formwork face of the panel and the reinforcement,

- And, some time after the end of the application of the AV potential difference, the formwork comprising the shuttering is separated from the reinforced concrete wall, the latter then being stripped.

According to another aspect, the subject of the invention is a system for producing a reinforced concrete wall stripped shutter with electrical polarization, comprising:

- a shuttering delimiting a shuttering space and comprising a shuttering having an electrically conductive shuttering face, suitable for a metal reinforcement to be placed there and for receiving current concrete chosen suitable for electrical polarization, - an electrical polarization device facilitating the stripping which has been described, including a polarization control device, electrically associated with the shuttering face of the form and with the reinforcement when functionally necessary,

- And means capable of separating the shuttering from the shuttered reinforced concrete wall, the latter then being stripped.

Depending on the embodiments, the panel is either a metal panel or a non-metallic panel, in particular a wooden panel, the formwork face of which is made electrically conductive, in particular by an electrically conductive coating.

According to one embodiment, the panel is standard. In particular, the panel supports, is capable of supporting, all or part of the means constituting the electrical polarization device.

According to another embodiment, the panel is a special electrical polarization panel which integrates either all or part of the means constituting the electrical polarization device or a specific means of supporting all or part of the means constituting the electrical polarization device.

According to one embodiment applicable to the production of a reinforced concrete wall shuttered with electrical polarization by means of two formwork faces electrically conductive of a pair of formwork defining an interbank formwork space.

The electrical polarization device can be removably supported by the two shutters and is located at least in part, in particular is located substantially, between the shuttering faces of the two shutters.

Depending on the case, the formwork comprises only said shuttering or additionally comprises at least one other lateral shuttering and / or at least one under-rise and / or at least one extension, structurally associated with said shuttering, the respective shuttering faces being associated electrically, and the shuttering space being formed of the respective shuttering spaces in communication with each other, in which the electrical polarization device is electrically connected either to only one or to several of the shuttering faces of said wall, of a another side branch, with an under-rise, with an extension.

According to one characteristic relating to the methods, devices and system described above, there is no operation of applying a form release agent to the electrically conductive formwork face of the form.

Figure 1 is a partial perspective view schematically illustrating a system for producing a shuttering reinforced concrete wall that can be stripped with electrical polarization, comprising a shuttering with two shuttering formwork faces electrically conductive, in the interbank space a metal frame and an electrical polarization device facilitating the stripping of which part of the connection means to the formwork face is visible. This figure also shows the framework of the shutters and their stabilization devices.

Figure 2 is a sectional and perspective view showing in more detail the system of Figure 1.

FIG. 3 illustrates the means of electrical connection to the formwork face.

FIG. 4 illustrates a reinforcement (reinforcement) and the means of electrical connection to the reinforcement. Figure 5 illustrates in more detail an armature connector means having teeth in the manner of a crenellated pliers. FIG. 6 represents a side view with a reinforcement with two plies, and also shows that the panel may include projecting and emerging lateral parts of the reinforcement not intended to be embedded in the concrete.

FIG. 7 shows a side view of two shutters, a single-ply frame with a projecting part upwards, and stabilization and working devices such as a platform associated with the panel.

Figure 8 shows a frame comprising two coplanar plies electrically butted together in the interbank space.

FIG. 9 represents a side view of two formwork, each with a sub-rise and an extension.

FIG. 10 represents a perspective view of two shutters, each with a shutter adjacent to it laterally, and also the framework of the shutters, stabilization and working devices such as a platform associated with the shuttering, devices for associating the shutters with each other. to the side laterally, and a protruding part towards the top of the frame.

Figure 11 illustrates, in the case of a single panel, the control means carried by the upper edge of the panel.

Figure 12 illustrates the case of a single panel in a horizontal position, for example to produce a poured concrete floor, or else to produce, in a prefabrication mode, any concrete element.

FIG. 13 is a side view illustrating two facing shutters whose shuttering faces are in electrical connection in series, to the negative terminal of the same source of electrical energy directly to the first shuttering face of a first shuttering and indirectly, via the first shuttering face and with a connection device, to the second shuttering face of the second shuttering.

FIG. 14 is a sectional view which shows a device forming a spacer and an electrical connection for the two formwork faces of the pair of formwork and an electrical connection of the frame.

FIG. 15 schematically illustrates an abacus which, for the concrete chosen, gives the duration ATa as a function of the ambient temperature Ture.

Figure 16 illustrates schematically, an abacus, which for the chosen concrete, gives the potential difference AV to be applied as a function of the ambient temperature Ture,

FIG. 17 illustrates a representative timing diagram of the polarization control, for an initial polarization sequence.

Figure 18 illustrates a representative timing diagram of polarization control, over a larger time base with an initial polarization sequence and subsequent polarization sequences.

Figure 19 illustrates the case of a so-called "tunnel" formwork.

detailed description

The invention aims to produce a reinforced concrete wall P shuttering and relates more particularly to the stripping of such a wall P with electrical polarization to facilitate stripping. The invention falls within the context presented in the introductory part. The following discussion is made with reference to the particular case where the wall P, having two opposite facings, is produced by means of a pair of shutters 1, 1a, 1b (the reference 1 designating a panel in general), coupled facing each other, defining a space forming 2 interbanks, if necessary by means of one or more ends (not shown) suitable for transversely closing the space interbanks 2, and / or a sub-rise 3 (see FIG. 9) arranged below and / or an extension 4 arranged above, and / or several pairs of associated forms side by side (see FIG. 10). Such a sub-rise 3, riser 4 or side panel is nothing more than a panel 1 as a formwork element for a concrete wall P, essentially comprising a frame 5 and a formwork face 6 which is one face of a shuttering structure 7. However, the invention is not limited to the case of two formwork, but relates to cases where there is a single form, or more than two formwork, or two formwork which are not facing each other apart from each other. The invention is applicable to the case of pouring a floor with a single panel in a horizontal position under the wall to be produced. The invention is applicable to the case of the casting of a tunnel configuration, namely a vertical wall and a horizontal wall meeting in a junction zone.

As illustrated in the figures, a panel 1 also includes additional equipment, such as in particular devices for maintaining, adjusting, stabilizing 1d, gripping, working as a platform 1e allowing an operator to be in the upper part of the panel, access 1f in particular in the upper part, protection, etc., as well as bolts, projections, notches, etc., etc. allowing to associate the panel 1, with an under-rise 3, an extension 5, a side panel. The frame 5 may include a wall 5a and stiffening parts 5b such as reinforcements / W-sections or the like.

According to embodiments, the frame 8 is in the form of bars, lattices (as shown in the figures) or cages. Figure 6 shows a frame comprising two parallel plies spaced apart and Figure 8 shows a frame comprising two coplanar plies electrically butted together in the interbank space. Such a frame 8 is arranged and maintained within the interbank space itself longitudinally and transversely and generally comprises one or more parts 8a, projecting and emerging not intended to be embedded in the concrete.

The process for making a wall P in reinforced concrete shuttering with electrical polarization is such that:

- There is available a formwork defining a formwork space 2 and comprising the two formwork each having a formwork face 6 conductive of electricity.

- we have available the current concrete selected suitable for electrical polarization.

- then, a metal frame 8 is placed in the formwork space 2, so that it is electrically isolated from the formwork faces 6.

- moreover, concrete was prepared, wasted at time TO, and the formwork space 2 was filled with this concrete, its compaction, in particular the end of it, being ensured, at time T1.

- Then, at the relevant moment and in an appropriate manner, the concrete is electrically polarized, by applying an electrical potential difference AV between the formwork faces 6 of the two forms and the reinforcement, by a polarization process and with a device for polarization 9, by means of a control method and a control device 10 of the electrical polarization. Thus, an electric field is thus applied between the formwork faces of the two formwork and the reinforcement, all electrically conductive, and therefore in the poured concrete itself, so as to obtain a non-stick separation on each formwork face, comprising water, between the formwork face and the facing of the wall P which, once the concrete has sufficiently hardened, facilitates the actual stripping operation.

- And, finally, a certain time after the end of the application of the potential difference AV, the shutters are separated from the shuttered reinforced concrete wall, the latter then being stripped. Thus, it is not necessary to provide for the application of a form stripping agent on each formwork face 6 of the formwork and there is no provision for the application of such a form stripping agent and finally the formwork face. is devoid of a form-stripping agent, or substantially devoid of such a form-stripping agent, traces of which may inadvertently and involuntarily remain.

A system for making a wall P in reinforced concrete shuttered with electrical polarization, is arranged so as to implement this method. He understands :

- a shuttering delimiting a shuttering space 2 and comprising a shuttering 1 having an electrically conductive shuttering face 6, suitable for a metallic frame 8 to be placed there and for receiving the current concrete chosen suitable for electrical polarization.

- an electrical polarization device 9 facilitating the formwork stripping capable of being controlled, electrically associated with the formwork face of each form and with the reinforcement, when this is functionally necessary.

As already indicated, this process can also concern only a single form, or more than two formwork, or two formwork which are not arranged vis-à-vis apart from each other. It may also relate to the case where at least one other side panel and / or at least one under-rise 3 and / or at least one extension 4 are provided, structurally associated with said panel or with the two panels of the pair of panels. In such cases, the respective formwork faces, on the same side, are coplanar, continuous and electrically associated. And the formwork space 2 is formed from the respective formwork spaces in communication with each other. In such cases, the electrical polarization device 9 is electrically connected either to one only or to several of the formwork faces of said panel, of another side panel, of an under-rise, of an extension.

Depending on the embodiments, the sheet is either a metal sheet (or a non-metallic sheet, in particular a wooden panel, the formwork face of which is made electrically conductive, in particular by an electrically conductive coating or the plating of an electrically conductive sheet.

Depending on the embodiments, the form may be of the standard type, in the sense that it is of the type currently existing on the market, that is to say stripped by means of the application on the formwork face of a stripping agent. The panel can also be a panel that can be qualified as a "special electrical polarization panel" which integrates either all or part of the means constituting the electrical polarization device 9 or a specific means of supporting all or part of the means constituting the device. of electrical polarization.

Thus, the form stripping process avoids the need for a form stripping agent and is simple to implement as detailed below.

With regard to the polarization process, to facilitate the stripping of the formwork faces of a pair of formwork while a metal frame has been placed in the interbank space 2 and current concrete chosen suitable for electrical polarization, previously wasted at a time TO, was poured into the formwork space and its compaction ensured, at a time T1, we proceed as follows: - There is an electrical energy source 11 having a positive terminal and a negative terminal, an electrical connection means for formwork face 12 and an electrical connection means for reinforcement 13,

- For the purpose of electrical polarization, the source of electrical energy 11, the electrical connection means for the formwork face 12 and the electrical connection means for the reinforcement 13 are electrically associated, so that the formwork faces are connected to the negative terminal and that the armature 8 is connected to the positive terminal of the source of electrical energy,

- then, at the appropriate time and in an appropriate manner, a difference in electrical potential of AV polarization is applied between the formwork face and the reinforcement.

Note that the electrical potential applied to the reinforcement (or to the reinforcements) is higher than the potential applied to the formwork faces (reinforcement at positive potential and formwork faces at negative potential).

An electric field is thus applied between the formwork faces 6 of the shutters and the reinforcement 8, all electrically conductive and mutually electrically insulated, and therefore in the poured concrete itself, so as to obtain on each formwork face a non-stick separation, comprising water, between the formwork face and the external face of the concrete wall (facing) which, once the concrete has sufficiently hardened, facilitates the actual stripping operation.

The potential difference AV is chosen appropriate to the polarization. For example, it is between 0.2 volts and 12 volts, more particularly between 0.5 volts and 6 volts, more especially between 1 volts and 3 volts.

According to the embodiments, AV is either a fixed or adjustable value, the electrical polarization method then comprising an operation of adjusting AV, in particular as a function of the ambient temperature Ture in which the wall P.

As regards the polarization device 9, to implement the polarization method, it comprises the source of electrical energy 11, an electrical connection means for the formwork face 12 comprising a conduction means for the formwork face 12a and a means connector for formwork face 12b, and electrical connection means for reinforcement 13 comprising conduction means for reinforcement 13a and connector means for reinforcement 13b.

Associated with this polarization device 9 is a polarization control device 10. According to the embodiments, the polarization device and the polarization control device are either integrated at least in part or structurally dissociated.

The embodiments envisaged and the characteristics set forth apply both to the polarization process and to the polarization device, the latter implementing the former.

The electric power source 11, of the direct current type, comprises, depending on the embodiments, a single battery or several batteries, suitable for delivering a direct current or else an alternating current source associated with an AC / DC converter.

An electrical connection means for formwork face 12 is suitable and intended to ensure an electrical connection of a terminal of the source of electrical energy with a formwork face, while an electrical connection means for reinforcement 13 is suitable and intended for ensure an electrical connection of another terminal of the electrical energy source with the armature 8. An electrical connection means 12, 13 typically and in general comprises an electrical conduction means 12a, 13a and an electrical connector means 12b, 13b. "Conduction means" should be understood as an organ made of an electrically conductive material, if necessary provided with electrical insulation, which in the context of the invention is rather extensive, like an electric wire. "Middle connector", should be understood as a member of an electrically conductive material, if necessary provided with an electrical insulation, which in the context of the invention is localized and not very extensive, like a contact or a terminal electric.

The electrical polarization process is such that the armature connector means 13b is electrically associated with the armature 8 itself, beyond any surface layer 14 of scale, oxidation, passivation or corrosion of the armature 8 affecting its electrical conduction with the armature electrical connector means.

The formwork face connector means 12a is electrically associated with the formwork face, so that the electrical conduction between the formwork face connector means and the formwork face is not adversely affected for the polarization.

Several methods can be envisaged for electrically associating the armature connector means 13b with the armature 8 itself. In one possible embodiment, the reinforcement 8 is pre-treated, at least in the area of electrical connection with the reinforcement connector means 13b, said treatment preventing or limiting the occurrence or development of a surface layer affecting the electrical conduction of the armature. In another possible embodiment, a protective means 15 of the armature, removable, is put in place beforehand in the zone of electrical connection with the armature connector means 13b, said protection means 15 preventing or limiting the occurrence or the development of a surface layer 14 affecting electrical conduction and said protective means 15 are removed or pierced to ensure the electrical connection.

In another possible embodiment, a higher potential difference - in particular clearly greater - than the difference is applied beforehand and briefly to the armature 8, in the zone of electrical connection with the armature connector means 13b. of polarization potential AV, to crack the layer 14 and ensure the electrical connection. We can apply a brief peak of a voltage of up to 100 Volts, or even 200 V, and given the very short duration of a few tens of milliseconds, the energy involved is not greater than an electrostatic discharge. common. This voltage peak makes it possible to clean any contact resistances that existed or were created between the connector medium and the armature, for example. This ensures that the desired electric field will be well established inside the concrete to cause water molecules to migrate.

In another possible embodiment, an armature connector means 13b specially designed so that when it is associated with the armature 8, it passes through the surface layer affecting the electrical conduction of the steel of the steel is arranged and used. 'armature, such as an armature connector means 13b having teeth in the manner of a crenellated pliers. In this latter embodiment, the polarization device 9 comprises an armature connector means 13b specially arranged so that when it is associated with the armature, it passes through the surface layer 14. Generally, the teeth of the crenellated clamp make it possible to establish a contact with negligible resistance between the medium connector and the armature body. This guarantees that the desired electric field will be well established inside the concrete to cause the water molecules to migrate.

The polarization method and the polarization device 9 which implements it can be the subject of different embodiments, as regards the electrical association with each formwork face. According to the embodiments, the formwork face connector means 12a can be electrically associated directly to the formwork face itself (see FIG. 2) or to its formwork structure 7, either on the formwork side or on the side opposite to the formwork side. According to the embodiments, the formwork face connector means 12a is associated with the formwork side of the formwork face, in a location which is preferably located outside that where the concrete fills the formwork space.

In the case where there is a pair of formwork, the two formwork faces 6 are connected to the negative terminal of the same source of electrical energy, either in parallel or in series, for example directly to the first formwork face of the first shuttering and indirectly, via the first shuttering face 6 and with a connection device 16, to the second shuttering face 6 of the second shuttering. Or, the two formwork faces are connected to the negative terminals of two sources of electrical energy.

In one embodiment, the formwork face connection means 12 passes through the frame 5 of the form or any other means constituting the form masking the side opposite to the formwork side where the electrical connection is provided Or else, the formwork face connector means 12a is placed at a place where the opposite side of the formwork face is accessible so as to be unmasked by the framework 5 or any other means constituting the panel.

In one embodiment, the formwork face connector means 12b is in electrical connection with the formwork face 6 or the formwork structure 7 indirectly via an electrically conductive means with low electrical resistance, in electrical conduction with the face. formwork 6. For example, the formwork face connector means 12a is electrically associated with the metal framework 5 of the panel or else with a metal insert passing through the metal framework 5 of the panel, the framework 5 of which may then be non-. metallic, or even to any other metallic means constituting the panel in electrical conduction with the shuttering face 6 or its shuttering structure 7, With such embodiments, said framework 5 or said insert or said other constituent means of the panel 1 make thus part of the electrical connection means for the formwork face 12.

According to one embodiment, the electrical association between the formwork face connector means 12b and the formwork face 6 itself or its formwork structure 7, does not affect or does not substantially affect the surface condition of the formwork face 6. for its part in contact with the concrete of the concrete wall. In doing so, the facing of the concrete wall P is not affected by the formwork face connector means 12a.

According to one embodiment, the electrical association between the reinforcement connector means 13b and the reinforcement 8 itself is produced in an electrical connection zone located outside the location where the concrete fills the formwork space 2. According to a another embodiment, this association is carried out in a location where the concrete fills the formwork space 2. In this case, in one embodiment, once the polarization has been made, either the part of the electrical connection means for reinforcement 8 located in the concrete of the wall of that located outside the concrete of the wall either the part of the electrical connection means for reinforcement 8 which was previously located there is removed from the concrete not yet sufficiently hardened, or the connection is still left in the concrete of the wall P. For reasons in particular of safety and good electrical distribution, according to one possible embodiment, the electrical connection is provided at least in duplicate with the formwork face 6 and / or at least in duplicate with the armature 8. In particular, the electrical connection with the formwork face 6 and / or with the reinforcement 8 is produced in respectively distant locations.

The polarization method is associated with a polarization control method, and similarly, the polarization device 9 is functionally associated with a polarization control device 10 capable and intended to implement the method of controlling the polarization. polarization.

Times, deadlines and parameters

In one embodiment, both for the process and for the device:

- to have, for the chosen concrete, the duration ATa between the moment TO of the mixture and the theoretical moment T2 of the start of setting of the concrete,

- and to control the start of the application of the difference in electrical potential of polarization AV at a moment T3 which follows the moment T1 with a delay ATc equal to (TO - T1) + (ATa - ATb), in which ATb is a desired anticipation period in relation to the start of setting of the concrete.

Depending on the possible embodiments, on the one hand, ATb is chosen between 0 and 145 minutes, more particularly between 15 minutes and 60 minutes, more especially between 15 minutes and 25 minutes.

Depending on the possible embodiments, on the other hand, ATb is a value which is either fixed or is adjustable. In the latter case, the control method then comprises an operation of adjusting ATb.

Having, for the chosen concrete, the duration ATa between the moment T0 of the mix and the theoretical moment T2 of the start of setting of the concrete, is known or within the reach of those skilled in the art. This ATa information can be provided in particular by the concrete manufacturer or the concrete preparer.

"Moment" should be understood as meaning a given instant and "delay" as meaning a given time interval. However, in the case of processes and devices implemented not in the laboratory but on a construction site, in more or less rustic conditions, there may be for the moments TO, T1, T2 or the time ATa, an approximation more or less important, these values or some of them being able to be only approximate or to include a margin of uncertainty or error more or less large, for example being able to reach of the order of several tens of minutes for a moment and of the order of +/- 10% for a duration or AV. Such deviations also apply to the other numerical parameters and are given by way of illustration.

In all cases, it is a question of controlling the start of the application of the difference in electric polarization potential before the start of setting of the concrete (future events) and this, with reference to the time of the mixing of the concrete ( known past event).

TO is the actual spotted moment of the waste. We can also consider that TO is the estimated or supplied moment of the waste. By actual spotted moment of the waste is meant the moment when the waste has taken place, which implies that this moment has been identified in one way or another. By estimated moment, we mean a moment which is not necessarily the actual and identified moment of the waste but the moment which has been estimated approximately, by reference to certain data relevant. By provided moment, we mean a moment which is not necessarily the actual and identified moment of the waste but the moment which was provided or which was obtained in one way or another.

Typically, the time TO can be provided, for example in the form of a timestamp, with the delivery of the concrete mixer, for example on paper, or on a digital delivery note, or even on an electronic label associated with the mixer truck. .

From the moment TO, the chemical reaction linked to the decomposed hydration of the concrete takes place inexorably and leads to a start of setting after an ATa delay. In practice, depending on the different types of concrete, the ATa delay can range from 1 hour to 3 hours. It is important for the application of the proposed process to know with a certain precision this delay ATa, this is why in addition to the precise type of compound concrete, the ambient temperature Ture is also taken into account either on the site or an average is taken. the ambient temperature in which the concrete has been located since the time TO of mixing.

Note that between mixing and pouring, the distance the concrete travels is no more than a few kilometers, and the concrete remains in the same climatic environment, with no substantial change in ambient temperature. Likewise, the time elapsed between mixing and pouring is low, i.e. of the order of 1 hour at most, often less than 30 minutes; weather conditions do not have time to change substantially, and concrete remains in the same climatic environment, with no substantial change in ambient temperature.

In one embodiment and with reference to Figure 15. it is, both for the method and for the device:

- to have a means of supplying ATa / Ture data, such as an abacus, which for the chosen concrete, gives the duration ATa as a function of the Ture ambient temperature,

- determine the ambient temperature Ture,

- And determine the duration ATa from the means for supplying ATa / Ture data.

In one embodiment and with reference to Figure 16. it is, both for the method and for the device:

- to have a means of supplying AV / Ture data, such as an abacus, which, for the chosen concrete, gives the potential difference AV to be applied as a function of the Ture ambient temperature,

- determine the ambient temperature Ture,

- And determine the potential difference AV to be applied from the AV / Ture data supply means.

This or these achievements make it possible to take into account the parameter which is the ambient temperature, which a person skilled in the art knows has an impact on the setting of concrete, and in particular on the start of setting. In doing so, the polarization is itself adapted to the ambient temperature Ture.

The means for supplying ATa / Ture data and the means for supplying AV / Ture data must be understood as a means which, for the chosen concrete, respectively gives the duration ATa and the potential difference AV to be applied as a function of the temperature ambient Ture. Such ATa / Ture and AV / Ture means can have different embodiments. In a particular embodiment, the means ATa / Ture and AV / Ture are graphic tables such as graphs or nomograms, specially established or available which give, for a chosen concrete, on the abscissa or on the ordinate the ambient temperature Ture and on the ordinate or on the x-axis, the duration ATa and AV, respectively. In another particular embodiment, the ATa / Ture and AV / Ture means are electronic and can be associated with a programmable or programmed controller, or else take the form of an information medium associated functionally with the control device. 10. In another particular embodiment, the ATa / Ture and AV / Ture means are virtual and accessible by a dedicated Internet application, or an Internet site, or via the “Cloud”. In another particular embodiment, the ATa / Ture and AV / Ture means form part of the knowledge possessed by the operator.

In the context of the invention, ATa and AV are given relative to the ambient temperature Ture by the data supply means ATa / Ture and AV / ure which have just been described which make it possible to locate ATa and AV, once the ambient temperature Known ture. Within the scope of the invention, the case where ATa and AV have been evaluated by reference to the room temperature Ture and the case where ATa and AV have been provided or have been obtained in some way.

According to the embodiments, the means ATa / Ture and AV / Ture give, for a given temperature, a single value of ATa and AV, respectively, or else, give a range of values surrounding a median value, which corresponds to number of charts of industrial processes.

As a variant, the duration ATa can be obtained from a more complex 3-dimensional or more mapping (temperature, ambient degree of humidity, sunshine, time of day, etc.)

The Ture ambient temperature taken into account with regard to the ATa / Ture data supply means and / or the AV / Ture data supply means, is the actual measured ambient temperature or the estimated or supplied ambient temperature. By actual ambient temperature identified, we mean the ambient temperature of the realization of the wall, which implies that this temperature has been detected in one way or another. By estimated temperature is meant a temperature that is not necessarily that, real and identified, but that which has been estimated approximately, by reference to certain relevant data. By supplied temperature is meant a temperature which has been supplied or which has been obtained in some way, for example by a weather station or an Internet application.

It is understood that the construction arrangements described lend themselves to automation, as the operator on the site does not have to carry out measurements, calculations, etc.

As illustrated in figure 17. the moment T1 generally designates the moment of pouring or compacting of the concrete in the formwork space 2. Since the compaction is carried out immediately after the pouring, one can choose the timestamp corresponding to the moment of pouring. or at the time of compaction. We will see later that whatever the reference point for T1, it works in an identical way, without affecting the relevance of the method.

According to the embodiments, the moment T1 is detected either automatically or non-automatically. Automatic detection can be ensured with, for example, a means associated with the formwork space 2, such as for example a detector of the presence and level of concrete in the interbank space 2. A non-automatic detection can be ensured, by for example, by the operator on the site who monitors the filling and compacting of the concrete in the interbank space 2 and gives a signal or actuates a command at time T 1.

With automatic detection of T1, automatic control of the start of the application of the potential difference AV at the moment T3 = T1 + ATc is made possible. One notes DT1 like the delay which separates the moments TO and T1. In other words DT1 = T1 - TO.

We have already seen above that: ATc = (TO - T1) + (ATa -ATb), namely written differently with reference to figure 17: ATc = ATa - ATb - AT1, or again ATa = DT1 + ATc + ATb

We obtain the remarkable result that the moment T3 is written in the form T3 = TO + ATa - ATb, and that the uncertainty related to the measurement of the moment T1 disappears. The critical data therefore appears to be TO and ATa, an error on T1 is irrelevant.

The control of the polarization is also concerned with the termination of the application of the AV potential difference. This occurs at the appropriate time T4 which follows the time T3 by means of a polarization delay ATd. For example, ATd is chosen to be between 10 minutes and 60 minutes, more particularly between 5 minutes and 30 minutes, more especially between 10 minutes and 20 minutes, these values being only indicative.

As illustrated in FIG. 17, ATd is chosen so that the moment T4 precedes the moment T2 of the start of concrete setting;

In one embodiment, ATd is a fixed value.

In another embodiment, ATd is a parameterizable value and the control method then comprises an operation of adjusting ATd. In particular, the setting of ATd is a function of the ambient temperature Ture, so that, all other things being equal and relative to an average ambient temperature, ATd is reduced if the ambient temperature Ture is greater than the average and ATd is increased if the ambient temperature Ture is smaller than the average. Where appropriate, provision may be made for a means of supplying ATad / Ture data, such as an abacus, in the sense that this has been previously explained for the means ATa / Ture and AV / Ture.

Provision may also be made in one embodiment to secure and control the control of the polarization - and, in the event of a malfunction indication, to notify, alert, or shut down the polarization.

Typically, security and control relate in particular to the following points:

- verification of the absence of an electrical short-circuit, or galvanic isolation, between the reinforcement and the formwork faces, the reinforcement being originally placed in the interbank space without electrical communication with their formwork faces,

- check that ATc has a positive value.

In the event of a short circuit detection or an open circuit detection, the fault type can be displayed to help resolve the fault in the circuit.

In practice, it must be ensured that the formwork structure is not connected to the earth and is floating with respect to the potential of the earth. In fact, the frame 8 is generally connected by foundation construction to the earth. In other words, polarization consists of applying a negative absolute potential to the formwork faces. It should be noted that the formwork is installed on wedges or slabs which are generally insulated from the earth. At least one data or parameter storage operation can be provided from among the concrete chosen, TO, T1, T2, T3, T4, ATa, ATb, DTo, ATd, AV, Ture, and / or indication of malfunction. , and / or at least one data transmission or communication operation, parameter, malfunction indication, and / or at least one data, parameter, malfunction indication printing operation.

In one embodiment, the polarization, including its control, may relate to one or more standard form 1s, as defined, which makes the invention versatile in that it can be used with any standard form. According to one embodiment, such a standard panel 1 supports, or is able to support, all or part of the means constituting the electrical polarization device 9, and / or the control device 10 thereof, for example on the upper edge of panel 1, or even on platform 1e. Or, all or part of the means constituting the electrical polarization device 9, and / or the control device 10 thereof, is placed on the ground next to the panel.

In the case where there is a pair of forms, the electrical polarization device 9 can, with reference to FIG. 13. Be supported in a removable manner by the two forms and be located, at least in part, in particular substantially, between the shuttering faces 6 of the two shutters, such as for example with an elastic extension system 17 coming to bear on the shuttering faces of the two shutters or on other parts of the two shutters, or else with a structurally different but functionally similar system. Such an elastic extension system 17 comprises, for example, a retractable / extensible member according to the distance between the formwork faces.

In another embodiment, the polarization may relate to one or more 'special electric polarization' forms which structurally integrates either all or part of the means constituting the electric polarization device 9 or a specific means of support for all or part of the means constituting the device. electrical polarization.

As a variant, at least part of the polarization control device 10 is structurally associated with the panel so as to be integrated therein or else the panel comprises a specific means of supporting a part of the control device 10, which may be similar. to the support. In this variant, the part of the control device structurally associated with the panel and the part of the control device not structurally associated with the panel can be functionally communicating through either a link or a physical interface such as a wired link or a connection means. or a non-physical interface such as a radio, Bluetooth or optical link. Still in this variant, the entire control device 10 can be structurally associated with the panel so as to be integrated therein. Depending on the case, part or all of the control device structurally associated with the panel is, on the one hand, either permanently or temporarily, on the other hand, either inseparably or in a separable and removable manner. .

In particular, there may be provided at least one functional box comprising control, adjustment, display and control means.

Thus, can be structurally associated with the wall:

- a means of controlling the start of the application of the potential difference AV, - a means of controlling the end of the application of the potential difference AV,

- a means of supplying ATa / Ture data,

- a means of supplying AV / Ture data,

- a means of determining the ambient temperature Ture,

- a means of automatic detection of the moment T 1.

In the case of a pair of formwork, comprising two electrically conductive formwork faces arranged opposite each other defining an interbank formwork space, the two formwork can be special electrically polarized or else one form is standard and the other special electrical polarization.

With a pair of forms, either a part of the electrical polarization device 9 structurally associated with a single branch or it is structurally associated with the two forms of the pair of forms. The same is true for the control device 10: part of this device is structurally associated either with a single panel or with the two panels of the pair of panels.

In FIG. 14 is shown a device 19, forming a spacer and an electrical connection. This device 19, combines a spacer connecting the two formwork faces of the pair of formwork and an electrical connection between, on the one hand, the two formwork faces connected to the anode - of the electric power source 11, and, d 'on the other hand, the armature crossed by the device 19, connected in one way or another to the + cathode of the source of electrical energy. For example, the device 19 comprises an inner part and an outer part which are coaxial electrically isolated. The inner part acts as a spacer and provides an electrical connection between the two formwork faces. The outer part, like a sleeve, is electrically connected to the frame.

By electrical connection of an armature, it is necessary to understand two embodiments. The one where it is the reinforcement arranged between the formwork that will be stripped which is connected directly to the source of electrical energy. The one where this reinforcement is connected only indirectly, insofar as on the site there is an equipotential bonding between the different reinforcements. Consequently, it must be possible to connect to the source of electrical energy not the reinforcement arranged between the forms in question, but another reinforcement at the same potential. Preferably, this other reinforcement is rather close to that disposed between the two forms.

According to an interesting optional feature, it can be provided after an initial electrical polarization phase SQO as illustrated above to carry out subsequent electrical polarization recall sequences. In this case, as illustrated in Figure 18. there is provided a first subsequent bias sequence SQ1 with an average voltage AVA1.

This sequence is started at time T31, which may be several tens of minutes or even a few hours later than the initial sequence SQO. The average voltage AVA1 can range from 3 V to 12 V. In the example illustrated, there are respectively second and third subsequent polarization sequences SQ2, SQ3 with respective average voltages AVA2, AV A3. The voltage levels AVAi increase with the temporal distance from the start of setting of the concrete T2. The duration of each sequence can be relatively short, for example about ten minutes; one-off reminders are thus formed without the need to consume electrical energy continuously. Advantageously, the first subsequent polarization sequence SQ1 is applied at least three hours after the start of the setting of the concrete T2, preferably at least six hours after the start of the setting of the concrete T2.

If we further consider that the end of the initial polarization phase T4 precedes T2, then no polarization is applied during the start of the concrete setting process. So polarization does not interfere with the chemical setting reaction of concrete. For example, it is left without polarization for the first six hours of setting of the concrete.

The other subsequent sequences SQ2, SQ3 can be spaced a few hours apart and each last about ten minutes or about fifteen minutes.

According to a particular example, AVA1 is worth 5 volts, AVA2 is worth 8 volts AV A3 is worth 10 volts.

Optionally, each of the polarization sequences (SQO, SQ1, ...) can start with a voltage peak which makes it possible to guarantee the correct establishment of the polarization current. This peak can be delivered by a pre-charged reservoir capacity which flows very quickly into the circuit when the bias circuit is established. As this peak is short, it has no influence on the migration of water and no influence on the average voltage value AVAi considered on the given sequence SQi.

Figure 19 illustrates the particular configuration of tunnel formwork in which a branch 1 disposed vertically and joined to a panel 1k disposed horizontally. Reinforcement / reinforcement 8 is installed both in the vertical formwork space and in the horizontal formwork space, preferably with electrical continuity. A concrete pour thus makes it possible to form a unitary concrete structure comprising a horizontal wall and a vertical wall, thus forming a tunnel-type formwork.

It should be noted that the device makes it possible to apply electrical stresses while remaining in the non-dangerous safety field of the very low voltage ELV field within the meaning of standard NF C15-100. Thus the companions on the site do not risk anything, even if they come into contact with the reinforcements and / or the panel body during a phase of polarization.

As long as this is not incompatible, the or some of the various embodiments described individually can be combined.

The terms and expressions used in the above description should be understood as was presented in the introductory part, in particular as regards: "wall of reinforced concrete" or by ellipse "wall" or "concrete wall" , “Shuttering”, “shuttering space”, “shuttering”, “pair of shutters” which should be understood as meaning “two shutters coupled facing each other, defining an interbank shuttering space”, “interbank space”, “face shuttering "which should be understood as meaning" shuttering face of a shuttering "and" shuttering face of a shuttering structure "," shuttering structure "which should be understood as meaning a wall, a covering, or the like having a shuttering face, "Framework" which must be understood as meaning "framework of a panel", "reinforcement" which must be understood as meaning "reinforcement for or of a reinforced concrete wall", "stripping", "facing", "mixing" , "Compaction", "concrete setting", "start setting of the concrete ”,“ operation of facilitating the stripping ”,“ stripping agent ”,“ electrical polarization of the concrete ”or by ellipse“ electrical polarization ”or“ polarization ”. "Associate", applied to means, must be understood as meaning that they are united, or joined, or allied, or interdependent, under a structural and / or functional angle, and that they act or have an impact on one another. As regards in particular electrical means, such as connection means, or conduction means, or connector means, “electrically associated” (or by ellipse “associated”) must be understood as meaning that these means are combined, or jointed, or connected, so that electrical continuity between them is ensured, with minimum resistance. “Integrated”, applied to means, must be understood as meaning that they are incorporated at least partially mutually, so as to form a coherent whole. “Dissociated”, applied to means, should be understood as the antonym of integrated and therefore means that the means in question are separate. "Structurally" or its variations, applied to one or more means, should be understood as relating to the form, or to the constitution, or to the arrangement, or to the arrangement, or to the organization, or to the manner of which it is or are realized, or of which they are arranged between them, of this or these means, whereas "functionally" or its variations, must be understood as relating to a function, that is to say a role played by the means or means in question, or the operations which it performs or which they perform, or is or are intended to perform, for the effect produced by the role played. “Having available”, in the context of a process, must be understood as meaning to dispose of, to have within reach, to obtain, to receive, to possess, to use, Unless this is not necessary or turns out to be excluded, the term "one" or "one" should be understood as meaning "at least one" or "at least one".

The expression “current concrete chosen suitable for electrical polarization” or any similar expression should be understood as meaning that the concrete constituting the concrete wall and which is used by the methods and devices described, is, at the same time , a common concrete, as understood by a person skilled in the art, a concrete chosen in its formulation and its characteristics according to the properties required in the fresh state and in the hardened state, the specific features of the wall to achieve, the conditions of its realization and its implementation, the envisaged application and the expected requirements, and finally a concrete suitable for electrical polarization in the sense that the application of an electrical potential difference between the formwork faces 6 of the formwork and the reinforcement 8, under appropriate conditions, has the effect that the water contained in the concrete migrates on each formwork face, which ultimately facilitates stripping.

Claims

1. Method for controlling an electrical polarization facilitating the stripping of a reinforced concrete wall (P), for a formwork having an electrically conductive formwork face (6) and delimiting a formwork space (2), whereas 'a metallic reinforcement (8) was placed in the formwork space (2) and that the current concrete chosen suitable for electrical polarization, was previously mixed, then was poured into the formwork space (2) and compacted, the electrical polarization being carried out by application, before the start of setting of the concrete, of an electrical potential difference of voltage AV between the formwork face (6) and the reinforcement, in which there is, for the chosen concrete, the duration ATa between the moment of mixing and the theoretical moment T2 of the start of setting of the concrete, characterized in that: while the effective moment of the mixing is TO, and that the moment when the compaction is ensured is T1, the start of the application of the electric potential difference is controlled at a time T3 temporally delayed from time T1 by an ATc delay defined by the equation:

ATc = (ATa - ATb) + (TO - T1), in which ATb is a desired anticipation time compared to the moment T2 of the start of the concrete setting.

2. The control method according to claim 1, wherein it is further provided that:

- the ambient temperature Ture is determined,

- we have a means of supplying ATa / Ture data, such as an abacus, which for the chosen concrete, gives the duration ATa as a function of the ambient temperature Ture, and

the duration ATa is determined from the data supply means ATa / Ture.

3. Control method according to one of claims 1 to 2, wherein it is further provided that:

- the ambient temperature Ture is determined,

- we have a means of supplying AV / Ture data, such as an abacus, which, for the chosen concrete, gives the potential difference AV to be applied as a function of the Ture ambient temperature, and

the difference in potential AV to be applied is determined from the AV / Ture data supply means.

4. The control method according to one of claims 1 to 3, wherein the end of the application of the potential difference AV is controlled at a time T4 temporally delayed from time T3 by a bias delay ATd, chosen included. between 10 minutes and 60 minutes, more particularly between 5 minutes and 30 minutes, more especially between 10 minutes and 20 minutes, and / or in which ATd is either a fixed or configurable value, and when ATd is configurable the process then comprises an operation for determining ATd, in particular as a function of the ambient temperature Ture.

5. Control method according to one of claims 1 to 4, wherein it is provided after an initial sequence of polarization (SQO) starting at time T3 and ending at time T4, one or more subsequent polarization sequences (SQ1, SQ2, SQ3).

6. The control method as claimed in claim 5, in which, for the subsequent polarization sequences, the polarization voltage (s) (AVA1, AVA2, AVA3) are higher than the polarization voltage of the initial polarization sequence. (from T3 to T4).

7. Control method according to one of claims 1 to 6, which comprises at least one security and control operation, such as:

- verification that DTo has a positive value, and the method further comprises, in the event of an indication of a malfunction, an information, alert or shutdown operation.

8. Control method according to one of claims 1 to 7, characterized in that it is applied to the stripping of a wall (P) of reinforced concrete shuttering with two shuttering faces (6) electrically conductive. a pair of formwork (1, 1a, 1b) defining an interbank formwork space (2), and there is provided an electric power source (11) having a positive terminal and a negative terminal for applying the electrical polarization between the formwork faces (6) connected to the negative terminal and the armature connected to the positive terminal.

9. Electrical polarization control device facilitating the stripping of a reinforced concrete wall (P) shuttered from the formwork face (6) electrically conductive of a panel forming part of a shuttering delimiting a shuttering space ( 2), while a metal reinforcement (8) was placed in the formwork space (2) and the current concrete chosen suitable for electrical polarization, wasted at time T0, was poured into the formwork space (2 ) and its compaction ensured at time T1, by applying a difference in electrical potential of polarization AV between the formwork face (6) and the reinforcement (8), with a source of electrical energy (11) having a positive terminal and a negative terminal, an electrical connection means for formwork face (12) and an electrical connection means for reinforcement (13), so that the formwork face (6) is connected to the negative terminal and the reinforcement (8 ) is connected to the positive terminal, for the implementation of the method according to any one d The claims 1 to 8, comprising:

a means for controlling the start of the application of the potential difference AV, at a time T3 which follows the time T1 with a delay DTo equal to (TO - T1) + (ATa - ATb), in which ATb is a desired anticipation time in relation to the moment T2 of the start of setting of the concrete.

10. Control device according to claim 9, which comprises a means for locating the effective moment TO, or a means for entering the estimated or supplied moment TO, acting on the means for controlling the start of the application of the potential difference. AV, and / or a means for adjusting ATb, acting on the means for controlling the start of the application of the potential difference AV.

11. Control device according to one of claims 9 to 10, which further comprises at least one of the following:

- a means of determining the ambient temperature Ture,

- a means of supplying ATa / Ture data, as for the chosen concrete, giving the duration ATa as a function of the ambient temperature Ture,

- a means of supplying AV / Ture data for the chosen concrete, giving the potential difference AV to be applied as a function of the ambient temperature Ture.

12. Control device according to one of claims 9 to 11, characterized in that it is applied to the stripping of a wall (P) of reinforced concrete shuttering with two shuttering faces (2) electrically conductive of a pair of formwork (1, 1a, 1b) defining an interbank formwork space (2) and in that the control device is associated with the pair of formwork.

13. A method of stripping a wall (P) of reinforced concrete shuttering and a shuttering face (6) of a shuttering (1) forming part of a shuttering delimiting a shuttering space (2), characterized in that 'it includes an electrical polarization facilitating the stripping by the method according to one of claims 1 to 8.

14. A method of stripping according to claim 13, characterized in that it is devoid of any operation of applying a stripping agent on the formwork face (6) electrically conductive of the shuttering (1).

15. Method of making a wall (P) in reinforced concrete shuttering stripped with electrical polarization, in which:

- a formwork delimiting a formwork space (2) and comprising a shuttering (1) having an electrically conductive formwork face is available,

- a metal frame (8) is placed in the formwork space (2),

- the formwork space (2) is filled with concrete, its compaction being ensured,

- With the control method according to one of claims 1 to 8, an electrical polarization is controlled, by applying an electrical potential difference AV between the formwork face (6) of the shuttering (1) and the reinforcement ( 8),

- And, some time after the end of the application of the AV potential difference, the formwork comprising the shuttering (1) is separated from the reinforced concrete wall, the latter then being stripped.