EP1420128A1 - Concrete surface and its method of production - Google Patents

Abstract

Concrete surface (1), especially for floor, has barrier layer (3) over foundation (2) to be covered by concrete surface layer (4). The barrier layer has number of raised sections (5) and/or recessed zones (6), to give it variable thickness. The covering layer is a concrete which does or does not incorporate fibers. The barrier layer is a structured sheet or film and especially of plastics or metal which repels water or is watertight.

Description

The present invention relates to a concrete surface, in particular a concrete floor, according to the preamble of claim 1 and a method for their Manufacture according to the preamble of claim 12 or 13. Furthermore The present invention relates to the use of a separating layer, in particular foil, sheet metal or the like, for producing a concrete surface, in particular a concrete floor, according to the preamble of the claim 15th

In the manufacture of monolithic, one-piece concrete floors it occurs during the setting and drying process of the concrete as a result of the Volume decrease to an uncontrolled crack or joint formation, in particular in the case of concreting large areas.

The prior art attempts this undesirable property of the concrete to meet in different ways.

It is currently assumed that the best way to avoid (shrinkage, setting) cracks for monolithic concrete floors is that you first one between the base course (= subsoil) and the concrete (= surface course) Provides sliding layer in the form of a plastic film, d. H. the concrete layer is applied to a plastic film arranged on the surface, and that afterwards (generally the day after concreting) so-called "Mock joints" cut into the surface of the concrete layer, in general at a mutual distance of approx. 5 to 7 m. This ensures that the concrete shortening that occurs in any case as a result of setting or Drying occurs in the dummy joints and no uncontrolled Cracks or gaps form between them. Alike will by inserting the plastic film avoided that the water in Fresh concrete escapes into the subsurface in an uncontrolled manner. This method is so far not efficient than joints in the day after concreting Concrete must be cut, and the joints are then closed or sealed and usually have to be renovated later. Of this method also places high demands on the flatness of the wing or the surface, otherwise the plastic film will not slide can, but what is required to avoid the shrinking or shortening to counteract the concrete when setting or drying.

Furthermore, it has been proposed by incorporating special Plastic fibers of certain dimensions in the concrete mass of formation of (shrinkage, setting) cracks when setting and drying the concrete counteract (see e.g. European patent EP 0 448 577 B1 of the company Danaklon A / S or its German equivalent DE 689 10 533 T2). In particular however, this method is not very effective for large areas. Of Furthermore, the homogeneous distribution of the fibers over the concrete mass is not always easy to reach. The practical experience with this method are also very limited.

The object on which the present invention is based is to provide it a method of the type described above, which the Disadvantages of the prior art at least partially avoided.

Another object is to develop a method for producing a concrete surface, in particular a concrete floor, in which the formation uncontrolled cracks as a result of the concrete setting or drying largely avoided or at least controlled.

Another task is to provide a method for the production of a seamless concrete surface, especially a seamless one Concrete floor.

Object of the present invention according to a first aspect of the present The invention is thus a concrete surface, in particular a concrete floor, with a separating layer arranged on a substrate and one on top of it arranged or applied cover layer made of concrete, the separating layer has a plurality of elevations and / or depressions, so that the thickness of the top layer varies.

The term "concrete" as used according to the invention is very extensive to understand and includes both concrete in the actual sense as well concrete-like hydraulic binders of all kinds, such as B. cements, mortar or similar.

The term "concrete surface" in the sense of the present invention encompasses concrete surfaces of any kind, both flat and uneven surfaces. In particular are concrete floors of any kind.

One of the special features of the concrete surface according to the invention, in particular Concrete floor, must be seen in the fact that the interface has a variety of elevations and / or depressions, so that the thickness of the concrete cover layer varied. So this means that the separation layer in repeating, preferably regularly recurring sections different Has thickness ranges. As a result, this varies the thickness of the Concrete cover layer over the elevations or depressions of the separating layer, as described in more detail below.

As explained in more detail below, the use of a separating layer leads of the type described above, among other things, to avoid uncontrolled Formation of gaps or cracks in the concrete surface, in particular concrete floor, or at least causes the formation of controlled (micro) cracks or (micro) joints in the concrete, especially cracks or joints less than 0.2 mm wide, which are harmless from a construction point of view. Without wanting to commit to a certain theory, the effect can be possibly explain the separation layer provided according to the invention by that the separation layer that when drying the concrete, cement, mortar or the like of the top layer absorbing shrinkage forces or evenly distributed over the area and controlled for training if necessary (Micro) cracks or (micro) joints. That will be later explained further. In this way, the provision or Cutting (dummy) joints as required in the prior art is to be avoided.

It is preferred according to the invention if the elevations and / or depressions regularly formed or arranged distributed over the separation layer are. In this way, maximum effect is achieved.

In general, the separating layer has a structured, preferably evenly structured surface. For example, the separation layer truncated cones or truncated pyramids (e.g. in the form of bumps, knobs, etc.), preferably in a more uniform manner Distribution.

The separating layer provided according to the invention can in particular be a preferably structured film, in particular plastic or Metal foil, or a preferably structured sheet. According to the invention it is preferred if the film is water-repellent or waterproof is formed, since it then also fulfills a sealing function. Examples are structured for plastic films suitable according to the invention (e.g. pimpled) polyolefin films (e.g. polyethylene or polypropylene films), such as are commercially available, for example. In the invention provided separating layer can in particular also be a preferably structured or profiled (e.g. deep-drawn) sheet metal ("Profile sheet") act.

According to a particular embodiment of the present invention the separating layer can be formed from the substrate or can be the separating layer form the underground at the same time.

Depending on the application, the thickness of the cover layer can be above the elevations or depressions of the separating layer vary widely. In general the thickness of the cover layer varies over the elevations or depressions the separation layer on average in each case by at least 5%, in particular by at least 10%, preferably by at least 15%, preferably at least by 20%, particularly preferably by at least 25%, very particularly preferably by at least 30%. In other words, this means that the (Average) thickness of the concrete cover layer due to the elevations or depressions varied by the aforementioned values, i. H. so above the surveys is shortened and thickened over the depressions.

For different purposes, fibers, especially plastic fibers, such as polyolefin fibers (e.g. polyethylene or Polypropylene fibers), metal fibers, glass fibers or the like his. The material, the nature, the quantity and the dimensions of such Fibers depend on the respective application and are familiar to the expert. For example, metal or glass fibers serve as a steel or reinforcing bar reinforcement, plastic fibers for fire protection purposes or for the additional inclusion of Forces from setting and early wasting are used, etc.

Likewise, it is possible to z. B. steel inserts, To bring monier iron etc., d. H. the concrete as reinforced concrete or the like train.

The concrete surface according to the invention, in particular concrete floor, is suitable for both indoor and outdoor use, especially for Large floor areas (e.g. hall floor, roadway floor, taxiway for Planes or the like). The concrete surface according to the invention, in particular Concrete floor is generally resilient, in particular passable.

In general, the concrete surface according to the invention, in particular concrete floor, poured, in particular cast in one piece, before and is preferred monolithic and seamless.

The invention provides a plurality of elevations or depressions separating layer (eg a "knobbed film" or "knobbed plate" made of plastic or metal, a profiled or deep-drawn sheet etc.) should, among other things, cause the shortening that occurs in any case of the concrete in as many, practically harmless, controlled or to divide controlled (micro) cracks or even crack completely suppress. The separating layer (e.g. pimpled film or plate) brings about this equally a "gearing" with the underground (the concrete of the The cover layer or cover plate thus remains essentially the same Place, d. H. Shifts should be deliberately avoided.), And on the other hand the elevations reaching into the concrete ("knobs") or Wells as quasi "crack indicator" or "crack initiator" (the total thickness of the concrete is weakened locally, which is due to these "weak points" primarily micro or nominal cracks occur after the voltage increase.). The theoretically developed constraining forces as a result Concrete shortening is thus divided into many small forces. Possibly certain fiber additives (plastic fibers such as polyolefin fibers, z. B. polypropylene fibers, or metal fibers, such as. B. steel fibers, or Glass fibers) these forces regardless of the basic dimension of the Master the interface. Ideally, one is the size of the concrete surface independently (e.g. in the case of large areas such as hall floors, Airfields etc.).

Without wishing to commit to a specific theory, the present Invention can be described by the following basic ideas:

With regard to the internal stresses of the concrete, the following can be determined: If you want to make yourself independent of the dimension of the surface, you have to all components that cause local movements or those medium dimensions are considered (dummy joints), forget. Around To achieve the situation, one has to deal with all locally occurring tensions locally can bind before they accumulate each other and dimensions achieve that are no longer manageable. But this is only via the detour to achieve the interlocking with the underground. So that’s flat foils, which have friction coefficients which are too small cannot be used according to the invention.

If a separating layer (e.g. a nubbed film or plate) having a large number of elevations or depressions is provided between the subsurface and the concrete of the covering layer, this separating layer prevents local shrinkage movements from being added up over large distances. For example, one can start from the assumption that the temperature coefficient α = 10 ^-5 is only effective in the locally limited area (e.g. 5 x 5 to e.g. 15 x 15 cm); Theoretically, a calculation of the permissible crack widths (e.g. 0.2 mm) with the expected temperature gradient and the shrinkage is possible. The big advantage here is that you no longer have to look at a test field in two dimensions, but that one dimension is enough (e.g. 1 x 30 m).

With regard to the load voltages, the following can be determined: Since in the invention Concrete surface, especially concrete floor, the joints In the end, only the tensile stresses on the underside of the panel remain (Field center). Together with the invention provided separating layer (e.g. "bubble film / plate") can be found at local Load even assume that on the "bottom" of the Interface do not form any real tensile stresses, but a kind Mini vaults. This is all the more true if the elevations or depressions ("Pimples") are less stable than the separating layer as such.

The concrete surface according to the invention, in particular concrete floor, is therefore based - in complete contrast to the conventional manufacture of monolithic or one-piece concrete floors (e.g. steel or fiber concrete floors), where between Base layer (subsurface) and construction concrete (top layer) one Sliding film is inserted to enable shrinking movements - on the fact that concrete is not given a possibility that is not prevent cumulative shrinking movements over longer distances. This is achieved by a between the base layer (subsurface) and construction concrete interposed special separating layer (e.g. "bubble film" or "profiled sheet"), which in the module of the Nub spacing hinders these movements and the forces that occur in dimensions that either depend on the respective strength of the Composite concrete can be picked up or if this strength is exceeded the movements in the form of many small, practically justifiable and thus compensates for harmless cracks. Like previously described, can the material of the separating layer ("bubble film" or "profile sheet") from Plastic to deep-drawn sheet metal actually contain all materials, which is stiff or rigid enough, the young concrete a certain To oppose movement resistance. The geometrical shape of the bubble wrap resembles a drainage film in which one level (possibly in the grid-shaped module) surveys, for example in the form of z. B. truncated cones or truncated pyramids, bumps, cones or the like, stand out. Such knobbed films are commercially available. The mode of operation of these knobbed films is then that on the one hand a (higher) static friction builds up against the base (base layer) on the other hand, the individual knobs on the top are the (plate) thickness or the thickness of the concrete of the top layer weaken and thus small provoke harmless cracks.

Without wishing to commit to a particular theory, the static How the end product works may be explained as follows: If floors are made without joints, they will fall on top of the Concrete surface on the joints due to external stresses Loads away (For example, it can be based on known and customary design methods bedded plates.). At the top of the concrete surface essentially only tensile stresses remain from constraining forces (Shrinkage, creep, temperature, etc.), whose deformations in the manner of many micro cracks can be compensated. The ones that appear at the bottom (Load) tensile stresses must be removed using the residual body (inside the knobbed film) of the concrete - possibly with the help of the composite cross-section of the concrete with the bubble wrap - to be included. If the load is above one Knoppe ("weak point", i.e. thinner concrete thickness), so the forwarding of forces as in a vault (supporting arch) within the concrete the train zone accomplished. The geometric shape of these knobs as well as the relative height of the "tip" of these knobs to the concrete slab thickness must ensure that no splitting or punching of the concrete caused becomes. The concrete product provoked by micro cracks can be used for the design certainly a lower one, d. H. therefore cheaper modulus of elasticity than the non-cracked concrete.

Bei günstig gewählten Dimensionen der strukturierten Trennschicht ("Noppenfolie") kann diese beim Verlegen an den Stoßstellen problemlos überlappt werden; beim Einbringen des Betons wird diese Verzahnung durch dessen Eigengewicht gesichert.

Die mögliche statische Verbundwirkung zwischen strukturierter Trennschicht ("Noppenfolie") und Beton kann die Konstruktionsstärke des Betons reduzieren. Ist der Modul der Noppen abgestimmt auf vorgefertigte Bewehrungseinheiten (z. B. Baustahlgittermatten), so kann diese Matte problemlos darin lagegerecht versenkt bzw. eingebracht werden; im Normalfall ist der Korrosionsschutz der gegebenenfalls zugelegten Bewehrung durch die Dichtheit der Noppenfolie gesichert, sie kann also direkt aufliegen. Die geänderte Verbundwirkung von Bewehrung und Beton ohne Betondeckung ist jedoch zu berücksichtigen.

Further advantages of the concrete surface according to the invention, in particular concrete floor, can be summarized as follows:

If the dimensions of the structured separating layer ("studded film") are chosen to be favorable, this can be overlapped without any problems when laying at the joints; When the concrete is brought in, this interlocking is secured by its own weight.

The possible static bond effect between the structured separating layer ("bubble film") and concrete can reduce the construction strength of the concrete. If the module of the knobs is matched to prefabricated reinforcement units (e.g. structural steel mesh mats), this mat can be easily sunk or inserted in the correct position; Normally, the corrosion protection of the reinforcement, if any, is ensured by the tightness of the dimpled membrane, so it can rest directly. However, the changed bond effect of reinforcement and concrete without concrete cover must be taken into account.

According to information from soil experts, the "non-area" introduction has the load forces (pressures) not a disadvantage, but rather an improvement Influence on the compression module as long as no "bad" ones Base layers (cohesive soils, grain sizes <0.2 mm, capillary water pulling Layers) are present.

In the case of dimpled sheets placed on thermal insulation boards, this can, if necessary remaining air space under the knobs also as thermal insulation to be viewed as.

The requirements for the flatness of the subsurface are not too great because Even larger unevenness can be compensated for by the interface can. The traditional manufacturing of industrial floors high demands on the evenness of the base layer or the subsurface, on which the conventionally used slide film is to be effective is omitted thus complete. Only the statically required plate thickness must be considered Minimum requirements are met.

The heating coils can be used when laying a planned floor heating in the correct position and, protected without additional measures, between the knobs or recesses / elevations are introduced if the knob module access is permitted during concreting. (The through the heating coils partially interrupted transmission surface by fibers be considered statically.)

Are daily joints required - e.g. B. in the event of interruptions in the concreting process over several hours - so they can be inserted vertically Studded mat can be designed to be push-proof. The train network will be there expediently by a module inserted under the formwork the knobs produced matching steel mesh mat strips.

In the meantime, the applicants have carried out numerous tests, including with a concrete concrete of the concrete quality C 25/30 according to the EN standard as a top layer concrete, to which steel fibers and plastic fibers (polypropylene fibers) have also been mixed. This concrete was applied to a plastic knobbed film, in a first experiment over an area of 52 m ² , in a second experiment over an area also of 52 m ² and in a third experiment over an area of 20 m ² , whereby in the first (second; third) experiment the concrete thickness varied from 5 cm (10 cm; 23 cm) above the raised areas of the dimpled sheet to 7 cm (12 cm; 25 cm) above the depressions of the dimpled sheet. There were no cracks in the cover layers within the one-month assessment period.

Fig. 1

eine schematische Darstellung einer erfindungsgemäßen Betonfläche, insbesondere eines Betonbodens, mit einer Trennschicht in Form einer Noppenmatte mit hohlen Noppen;

Fig. 2

eine schematische Darstellung einer erfindungsgemäßen Betonfläche, insbesondere eines Betonbodens, mit einer Trennschicht in Form einer Noppenmatte mit Vollnoppen.

Further advantages, properties, aspects and features of the concrete surface according to the invention, in particular a concrete floor, result from the following description of a preferred exemplary embodiment of the present invention shown in the drawing. It shows:

Fig. 1

a schematic representation of a concrete surface according to the invention, in particular a concrete floor, with a separating layer in the form of a knobbed mat with hollow knobs;

Fig. 2

is a schematic representation of a concrete surface according to the invention, in particular a concrete floor, with a separating layer in the form of a knobbed mat with full knobs.

1 and FIG. 2 schematically show a concrete surface 1 according to the invention, in particular a concrete floor, with one arranged on a base 2 Separating layer 3 and a cover layer 4 made of concrete arranged thereon, the separating layer 3 has a plurality of elevations 5 or depressions 6, so that the thickness of the cover layer 4 varies. As a separating layer 3 can in particular be a nubbed film (e.g. made of plastic or Metal) are used, the surveys 5, z. B. in the form of truncated pyramids or frusto-conical bumps, knobs or the like. These elevations 5 can be hollow, i. H. between the elevations 5 and the underground 2 is air (Fig. 1), or these elevations 5 consist of the separating layer material ("full pimples") (Fig. 2). The specially designed separation layer 3 provided according to the invention prevents an uncontrolled formation of joints or cracks when tying or

Drying the concrete cover layer 4 and possibly leads to formation controlled, structurally harmless (micro) cracks.

Subject of the present invention according to another, second Aspect of the present invention is a method for producing the invention Concrete surface, especially a concrete floor. Another The present invention thus relates to a method for the production a concrete surface, in particular a concrete floor, with one on one Separation layer arranged on the ground, on top of which a cover layer made of concrete is applied (e.g. poured), with a large number of separating layers separating layer having elevations or depressions is so that the thickness of the cover layer varies. The invention also serves Method of avoidance or suppression or at least the control of the formation of joints and cracks in concrete floors.

In other words, the method according to the invention is concerned a method for producing a concrete surface, in particular a concrete floor, especially as previously described, the concrete surface being seamless is poured from concrete and the concrete surface with alternating areas less and greater thickness is poured, so that an uncontrolled Joint or crack formation is avoided or controlled (micro) cracks are formed in the concrete or the areas of reduced thickness Form micro or predetermined cracks in the concrete.

The phrase "alternating areas of lesser and greater thickness" includes, for example, embodiments in which these areas in the Vary the type of egg carton, d. H. the areas of lesser thickness are not connected, but distributed in a grid-like manner over the concrete surface and, in particular, any local area of reduced thickness is complete is surrounded by an area of greater thickness. If necessary, the concrete surface but also be complementary to it.

For further refinements and designs of the method according to the invention can refer to the above statements on the concrete surface according to the invention, in particular concrete floor, referenced in relation to the invention Procedures apply accordingly.

Subject of the present invention according to a further, third Aspect of the present invention is the use of a separating layer, in particular film, sheet metal or the like, for producing an inventive Concrete surface, especially a concrete floor, with one on one Separating layer arranged underground and a layer arranged thereon or applied top layer made of concrete, with a variety of separating layers separating layer having elevations and / or depressions is so that the thickness of the cover layer varies.

For further refinements and designs of the use according to the invention can refer to the above statements on the concrete surface according to the invention, in particular concrete floor, which are referenced in relation to the use according to the invention apply accordingly.

Further refinements, modifications and variations of the present Invention are readily apparent to those skilled in the art upon reading the description recognizable and realizable without being beyond the scope of the present Invention leaves.

Claims (16)

Concrete surface (1), in particular concrete floor, with a separating layer (3) arranged on a base (2) and a cover layer (4) made of concrete applied thereon,
characterized in that the separating layer (3) has a multiplicity of elevations (5) and / or depressions (6) so that the thickness of the cover layer (4) varies. Concrete surface according to claim 1, characterized in that the separating layer (3) has a plurality of elevations (5) and / or depressions (6) to avoid uncontrolled formation of joints or cracks and / or to form controlled (micro) cracks in the concrete. Concrete surface according to claim 1 or 2, characterized in that the elevations (5) and / or depressions (6) are regularly distributed over the separating layer (3). Concrete surface according to one of the preceding claims, characterized in that the separating layer (3) has a structured, preferably uniformly structured surface and / or in that the separating layer (3) has truncated cones or truncated pyramids, in particular in the form of knobs, preferably in even distribution. Concrete surface according to one of the preceding claims, characterized in that the separating layer (3) is designed as a preferably structured film or sheet, in particular plastic or metal film, in particular where the film can be water-repellent or watertight. Concrete surface according to one of the preceding claims, characterized in that the separating layer (3) is formed by the substrate (2). Concrete surface according to one of the preceding claims, characterized in that the average thickness of the cover layer (4) due to the elevations (5) and / or depressions (6) of the separating layer (3) by at least 5%, in particular by at least 10%, preferably by at least 15%, preferably at least 20%, particularly preferably by at least 25%, very particularly preferably by at least 30%. Concrete surface according to one of the preceding claims, characterized in that the cover layer (4) and / or the entire concrete surface (1) is formed without joints and / or that the cover layer (4) (micro) cracks and / or (micro) joints having. Concrete surface according to one of claims 1 to 8, characterized in that fibers, in particular plastic fibers, such as polyolefin fibers, metal fibers, glass fibers or the like, are incorporated in the concrete of the covering layer (4). Concrete surface according to one of claims 1 to 8, characterized in that the concrete of the cover layer (4) contains no fibers. Concrete surface according to one of the preceding claims, characterized in that the concrete surface (1) forms a large-area floor area for indoor or outdoor use, in particular a hall floor, a carriageway floor, a tarmac for aircraft or the like, and / or that the concrete surface (1) resilient, in particular passable, and / or that the concrete surface (1) is cast, in particular cast in one piece, and / or that the concrete surface (1) is monolithic and / or joint-free. Method for producing a concrete surface (1), in particular a concrete floor, in particular according to one of claims 1 to 11, with a separating layer (3) arranged on a substrate (2), to which a cover layer (4) made of concrete is applied,
characterized in that a separating layer (3) with a plurality of elevations (5) and / or depressions (6) is used, so that the thickness of the cover layer (4) varies. Method for producing a concrete surface (1), in particular a concrete floor, in particular according to one of Claims 1 to 11, the concrete surface (1) being poured from concrete without joints,
characterized in that the concrete surface (1) is poured with alternating areas of smaller and greater thickness, so that an uncontrolled formation of joints or cracks is avoided and / or controlled (micro) cracks are formed in the concrete and / or the areas of reduced thickness are micro - or form cracks in the concrete. Method according to claim 12 or 13, characterized by the features of the characterizing part of one or more of claims 1 to 11. Use of a separating layer (3), in particular foil, sheet metal or the like, for producing a concrete surface (1), in particular a concrete floor, in particular according to one of claims 1 to 11, with a separating layer (3) arranged on a substrate (2) and a the top layer (4) made of concrete,
characterized in that a separating layer (3) having a plurality of elevations (5) and / or depressions (6) is used as the separating layer (3), so that the thickness of the covering layer (4) varies. Use according to claim 15, characterized by the features of the characterizing part of one or more of claims 1 to 11.

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