DE4421839C1 - Formwork panel made of concrete - Google Patents

Abstract

To give a lightweight lost concrete shuttering panel (1) adequate strength it is proposed to lay threads (5, 6), especially glass fibres, in criss-cross array in the region of the shuttering panel subject to tensile stress in use. In order to increase the strength of the shuttering panel further, fibres may be also be laid in the regions subject to compressive stress. It is proposed that glass fibres be used as they have the advantage of higher tensile strength for a given weight and are resistant to corrosion in the concrete. The side (9) of the shuttering panel facing the in-situ concrete (18) is to form an intimate bond therewith and is chamfered at its edges (13).

Description

The invention relates to a thin, manually transportable and Layable formwork panel made of concrete for a reinforced concrete component.

Under a lost formwork here is a formwork for one understood on site in cast concrete, the after setting the concrete is not removed, but with the Structure remains connected - be it that it lies in the ground and cannot be removed, be it as a load bearing or shaping part of the building is used.

A lost formwork panel is known (EP 0 110 874 B1), where a flat or spatial reinforcement steel mesh between two prefabricated, correspond to the reinforcement steel mesh enough panels and embedded this ensemble using concrete is cast in a monolithic supporting structure. The Ver drive to manufacture this formwork panel is very expensive and therefore the plate is expensive. Because reinforcement steel according to regulations the plate must be covered by at least 2 cm of concrete inevitably so thick that it changes the dimensions and closes is difficult than being handled by a single person, for example can be had.

Other common lost (sub) formwork panels for so-called Slab ceilings with concrete consist of the for the statics of the Required spatial reinforcement from steel bars, the only in their lower, when installed, on train bean area is poured into concrete. After installation, too the upper area of the reinforcement is cast with in-situ concrete and so that the ceiling is created. Because the reinforcement for every building  is calculated statically individually, formwork panels for such slab ceilings are made to order. This not only makes their production more expensive, it also complicates them Disposition during manufacture, storage, transport and on the construction site.

It is also a concrete formwork that can be used as a building element known (DE 17 05 248 U), but which has no reinforcement. Around sufficient strength not only when handling, but also to ensure when pouring with in-situ concrete, such a Formwork panel, however, so thick and therefore so heavy that it would no longer be manageable manually.

The object of the invention was therefore to create a lost one Formwork panel to create that as applicable building standards and rules the standard part taking into account the architecture in large quantities Manufactured cheaply, stocked and for all applications is equally applicable. It solves this task through the Characteristics of the main claim mentioned features.

The reinforcement of the formwork panel according to the invention is not that the structure of the structure causing steel reinforcement, but one reinforcement that only brings about the strength of the formwork panel. The the structure's structural reinforcement is above and thus regardless of the formwork panel according to the invention builds. This removes the formwork panel from the reinforcement of the building works independently and can be used universally in all structures be set.

There are already boards, preferably made of plaster, for production a lost formwork known (DE-GM 77 14 361), the one or embedded on both sides in the surfaces of the plates Have inlays made of a fabric or a fleece. These Inlays protrude from the panel on the narrow sides, around the Bond effect between the plates and the one to be inserted To increase core concrete. While it is mentioned that these deposits are the Increase the tensile strength of the plates. A fleece, but also a However, any type of tissue cannot be combined with plaster Formwork panel achieve the sufficient strength for formwork  of steel-reinforced ceilings to be created in cast concrete. Accordingly, the panels are only used to form walls proposed. In addition, the material-related chemical properties of gypsum on the one hand and steel reinforcement on the other hand to the steel processes that corrode steel, through which not only the reinforcing steel ver strength liert, but also the structure of the building is impaired.

The formwork panel according to the invention is therefore made of concrete and has a type of reinforcement that is in connection with the concrete the required strength when the plate is thin gives. The reinforcement in the lower, in the horizontal installation state area subject to tension has the necessary ar associated traffic load plus the load of the applied in-situ concrete. Another in which in the pre installation condition under pressure, upper area of the Formwork panel inserted reinforcement serves the formwork to make the board shatterproof when handled. This reinforcement can therefore be weaker than that in the area under tension.

In accordance with the invention, intersecting shares serve as reinforcement parallel, one-dimensional body like (monofilament) wires or (multifile) threads made of corrosion-resistant material high Tensile strength and low elongation. Meet these conditions especially wires or threads made of inorganic substances such as Glass. With particularly high demands on strength and low Weight can be justified by the use of carbon fibers his.

For the present application, glass has the advantages

• - that it is due to its essentially mineral Is a material that is very similar to concrete therefore also connects very intimately with the concrete Temperature changes react similarly to concrete, etc .;
• - That it has a very high tensile strength, which already with low wetness and thus weight results in high strength;  
• - That it has a modulus of elasticity similar to that of concrete and therefore behaves in a similar way to concrete when loaded;
• - That threads and fabrics made of glass fibers are commercially available and so it is easily available and cheap semi-finished product.

According to the invention, the formwork panel is preferably reinforced at least two, then preferably at an angle of Crossing 90 ° and parallel to the sides of the formwork panel trending sheets of thread. If formwork panels in other than mutually perpendicular directions are most heavily loaded are or if not rectangular formwork panels (e.g. the same triangular in buildings with a 60 ° grid plan) the thread coulters can also be used in others Cross angles. However, the thread sheets preferably run in Direction of the heaviest strain on the train.

For higher demands on the strength of the formwork panel or when the formwork panel is loaded in several directions can also use more than two, for example three sets of threads be, which are then advantageously at angles of approximately 60 ° cross.

The individual threads of the thread sheets have a mutual one Distance that the passage of liquid concrete through by the crossing stitches formed stitches allowed. Each after the grain of the concrete used, this distance can be from a few mm up to about 15 mm.

The strength of the reinforcements can be selected by choosing both the thread thickness as well as the mutual distance of the threads in the thread flock selected according to the demands on strength will. It has been shown that the required strength of the Formwork panel according to the invention with a reinforcement in the form of a textile fabric (fabric or cross-linked thread coulters) with a basis weight of about 100 g / m² is. In some cases, other plate dimensions or other stress values can also be higher or lower m² weights can be advantageous. Different or the same Basis weights can be with threads of different fineness  and / or different distance between the threads will.

As a rule, the upper reinforcement can be chosen weaker than the lower reinforcement, its basis weight, d. H. the concentration and / or the strength of their threads may be less than that in the thread sheets of the reinforcement in the lower area.

The crossing thread sheets can be independent of each other his. For the sake of the lighter, especially common hand availability, however, they are connected or networked and form a two-dimensional, flat structure. There the tensile stress, however, only ever from the individual threads is included, the links of the reinforcement are one-dimensional to address ionally. The threads can be crosslinked by gluing, Welding or enveloping coating can be achieved. Before preferably the groups of threads are together as a warp and weft interwoven, but for the purpose of the sliding resistance of the very light (with a large mutual distance between the threads) Fabric also a coating, welding or gluing is advantageous.

By using the thin thread coulters as reinforcement, the Thickness of the formwork panel according to the invention kept so small be that the height of a ceiling despite installing a Stahlar the above the formwork panel is not increased. Preferably is the lost formwork sheet just so thick that the pre written concrete thickness below or above the steel reinforcement of 2 cm given is. This means that the steel reinforcement can be used directly without the otherwise required spacers, placed on the formwork panel will.

A steel reinforcement must be replaced by at least one 2 cm thick concrete layer must be covered. This is due to the min guaranteed minimum thickness of the formwork panel. So that condition is also met at the joints of the formwork panel provided the edges of the formwork panel on top of the in-situ concrete chamfer facing side. This ensures that the height the remaining butt joint between the formwork panel is reduced  and that thin concrete glue seep into this butt joint can and it fills in and so the prescribed concrete thickness under or above the reinforcement.

Since the formwork panel and in-situ concrete are only on one level surface touch, it is intended to place the formwork on its place Concrete facing side so that an intimate connection between the formwork panel and the in-situ concrete. This can be due to the rough surface design of the formwork panel can be achieved. This surface of the formwork panel can also be used have undercut recesses in a known manner, in which the in-situ concrete enters and anchors. Grooves in the Surface of the formwork panel have proven to be a means of reaching Proven connection between formwork panel and in-situ concrete.

The dimensions of the formwork panel can be chosen arbitrarily will. A standard size of 100 cm × 50 cm corresponds to the standard size usual formwork panels. In some cases, however dimensions deviating from this may be advantageous.

The intended thickness of the formwork panel of about 2 cm and one preferred length and width dimensions of 100 cm and 50 cm lead to a weight of the formwork panel of about 25 kg, the one person handling the formwork panel alone leaves.

The intended thickness of the formwork panel of about 2 cm allows also easy cutting of the panels to partial dimensions stone-cutting release agents such as stone saws or cutting discs. It has been shown that the lower reinforcement through separating incision is sufficient to make the formwork panel along the To be able to break incisions.

In a further embodiment of the invention it is proposed that Formwork panel on its side facing away from the in-situ concrete with a Insulation layer against heat / cold, against sound or other in effects. This has the advantage that a such insulation layer not in a separate operation on Construction must be installed. Rather, you can already at  Manufacture of formwork panels in a more economical way Way.

The formwork panel according to the invention is mainly on the he places of cast, reinforced concrete ceilings. she can but also as lost formwork for walls, for beams, serve for recesses, for foundations etc.

In the figures of the drawing, two embodiments of the Formwork panel according to the invention and several possible uses the same as examples. Show it

Figure 1 shows the cross section through a formwork panel.

Figure 2 shows the formwork of a ceiling using the formwork panel in section.

Figure 3 shows the formwork of a beam using the formwork panel in section.

Figure 4 shows the shelling of a building foundation by means of the Scha development panel in section.

Figure 5 shows the shell of a recess by means of the processing board in section.

Fig. 6 is a created by means of the formwork wall in section;

Fig. 7 is a formwork panel with insulation layer in section.

As can be seen particularly in FIG. 1, the erfindungsge Permitted formwork panel 1 of a flat plate 2 made of concrete before preferably with a grain size no coarser than 8. In the claimed to train with horizontal installation area of the formwork panel 1 close above its bottom 3 contains this plate is a reinforcement 4 in the form of an insert of two intersecting shares 5 , 6 , each with parallel threads. In the embodiment to the left of the breaking line 7 , these sets of threads 5 , 6 form a fabric 8 , in the embodiment to the right of the breaking line, the sets of threads lie one above the other. In order to prevent the threads from shifting during the manufacture of the plate 2 , the threads of the thread coulters, which are only superimposed, are connected to one another in a sliding-resistant manner at their crossing points.

The top 9 of the plate 2 has a profile, which in the embodiment to the left of the break line 7 is designed as a dovetail-shaped, longitudinal or transverse grooves 10 in the embodiment, in the embodiment to the right of the break line as a longitudinal or transverse grooves or intersecting grooves 11 . Below this profiling 10 , 11 , the plate 2 contains a further reinforcement 12, likewise in the form of an insert made of intersecting shares 5 , 6 with threads which are parallel to one another and which are likewise interwoven or can only lie one above the other.

The edges 13 of the plate 2 are chamfered towards the top 9 in the manner of a chamfer 14 reaching approximately up to half the thickness of the plate. The thickness of the plate 2 is preferably 2 cm.

To produce a ceiling 15 with formwork panels 1 , these are laid out according to FIG. 2 on a support structure 16 indicated by dashed lines with the narrowest possible gaps in the top / bottom orientation shown in FIG. 1. The steel reinforcement 17 is placed directly on this formwork sheet layer without a spacer. The ceiling 15 can be poured directly onto this base using in-situ concrete 18 .

During this pouring, concrete flows into the grooves 19 formed by the chamfers 14 and low-viscosity concrete glue in the gaps between the edges 13 of the formwork panels 1 . This ensures - starting from the thickness of the formwork panels 1 of 2 cm - that the steel reinforcement 17 is covered at all points by at least 2 cm of concrete. After the concrete has set, only the support structure 16 needs to be removed. There is no need to knock formwork panels off of concrete surfaces and plaster the pouring bars.

To manufacture a girder 20 as shown in FIG. 3, Scha slate strips 21 are cut to the appropriate dimensions and BEFE by means of the dashed 22 indicated BEFE Stigt. After inserting the beam reinforcement 23 (and a ceiling reinforcement, not shown here), the ceiling 15 and the beam 20 are cast. As can be seen, the prescribed covering of the reinforcement 23 by concrete is also ensured here by the flow of concrete into the chamfers 14 and of concrete glue in the subsequent gaps.

The lost formwork panel according to the invention can also be used with advantage for the production of a foundation strip 24 in the ground according to FIG. 4. For this purpose, a formwork panel 1 forming the outside of the foundation strip 24 can be set up in the excavated foundation trench, for example by means of a floor nail 25 or other suitable splicing. The inside of the foundation strip 24 can be limited by means of a formwork strip 26 if it is not to be limited by the slope of the excavated foundation trench.

In-situ concrete 18 can then be poured into the space thus defined. After it has set, the ground nail 25 can be pulled, whereby the foundation is completed without the need to remove formwork.

Fig. 5 shows the Seat shell, the shells in reversal of a joist according to Fig. 3 a recess 27 in a cast concrete ceiling 15 or wall. The space of the provided recess 27 is clad on all sides with appropriately cut strips 21 of formwork plates, which are held by support elements 16 . The strips 21 of the formwork panels are arranged with respect to their bevels 14 so that the concrete layer above a lying in the ceiling 15 , not here, due to the inflow of in-situ concrete described above into the grooves formed by the bevels or of low-viscosity concrete glue in the remaining columns Darge presented reinforcement is ensured.

A wall 28 created by means of the formwork panels according to the invention is shown in FIG. 6. The formwork panels 1 are placed in channels 29 of a floor rail 32, which is fastened in the floor 31 , for example by means of nails 30 , or are held in a corresponding cover rail 33 . Steel tie rods 34 are inserted at correspondingly drilled-out locations of the butt joints of the formwork panels 1 , which, like the bottom rail 32 and the top rail 33 , absorb the pressure of the poured, liquid in-situ concrete. The wall 28 also has a steel reinforcement 17 . A support structure for holding the formwork until the in-situ concrete solidifies has already been removed here.

A formwork panel provided with an insulation layer 35 is shown in FIG. 7. It initially consists of the actual formwork panel 1 as shown and described in FIG. 1. On its underside 3 , that is, the side turned away from the in-situ concrete, an insulation layer 35 is arranged to prevent the passage of heat, sound or other influences, such as electromagnetic radiation or fire. The insulation layer 35 can also be provided and designed to absorb effects such as sound.

The insulation layer 35 consists of material known to the person skilled in the art which has the intended insulation effect, for example from hard foam such as Styrodur, from fiber material such as felt or rock wool, from multilayer panels which can contain combinations of these materials with flat structures such as cardboard, foils or sheet metal or from others . The insulation layer 35 is firmly connected to the actual formwork sheet 1 , for example by means of (plastic) nails 36 or by means of adhesive.

The formwork panel 1 according to the invention can be produced by first inserting the lower reinforcement 4 into a pan-like, flat shape. The mold is then filled with the intended amount of concrete. As a result of the large meshes in the reinforcement fabric, concrete passes through the fabric and also envelops it on the underside. The upper armature tion 12 is placed on this concrete filling and then the mold is closed with a lid. The shape forming the bevels 14 and the grooves 10 or grooves 11 is incorporated into this cover - the cores forming the grooves 10 can be designed as rails which can be drawn in the longitudinal direction. The projections in the lid press the upper reinforcement 12 into the concrete. The setting of the concrete can be accelerated by the action of heat on the form. The formwork panels can be mass-produced with a large number of ladles.

According to another method, a quasi-endless formwork can be built Blackboard tape manufactured continuously and individual boards after Setting of the concrete.

Reference list

1 formwork panel
2 plate
3 bottom
4 lower reinforcement
5 , 6 thread groups
7 fault line
8 tissues
9 top
10 grooves
11 grooves
12 upper reinforcement
13 edges
14 chamfers
15 blanket
16 support structure
17 steel reinforcement
18 in-situ concrete
19 groove
20 beam
21 formwork panel strips
22 Sprite
23 Beam reinforcement
24 foundation strips
25 ground nail
26 formwork panel strips
27 recess
28 wall
29 channels
30 soil nail
31 bottom
32 floor track
33 cover rail
34 tie rods
35 insulation layer
36 nail

Claims (13)

1. Thin, manually transportable and installable formwork panel made of concrete for a reinforced concrete component, characterized in that it has only the intended strength of the formwork panel ( 1 ) causing reinforcement ( 4 ) from at least two crossing thread sheets ( 5 , 6 ) made of corrosion-resistant material , which are embedded in the concrete at least in the area of the formwork panel that is subject to tension in the installed state, the edges ( 13 ) of the formwork panel being chamfered on the side ( 9 ) facing the in-situ concrete in such a way that the reinforcement to be installed in the reinforced concrete component ( 17th ) can be placed directly on the formwork panel and is therefore also protected against corrosion in the joint area and the in-situ concrete ( 18 ) facing surface of the formwork panel is designed such that an intimate connection between the formwork panel and the in-situ concrete is ensured in the installed state. 2. Formwork panel according to claim 1, characterized in that a reinforcement ( 12 ) of intersecting thread sheets ( 5 , 6 ) is embedded in the concrete even in the area of the formwork panel ( 1 ) which is subjected to pressure in the installed state 3. Formwork panel according to claim 1 or 2, characterized in that the thread sheets ( 5 , 6 ) run parallel to the sides ( 13 ) of the formwork panel ( 1 ). 4. Formwork panel according to one of the preceding claims, characterized in that the thread groups ( 5 , 6 ) are connected to one another at the crossing points of their threads by gluing, welding or coating. 5. Formwork panel according to one of the preceding claims, characterized in that the thread groups ( 5 , 6 ) are interwoven. 6. Formwork panel according to one of the preceding claims, characterized in that the thread sheets ( 5 , 6 ) consist of glass fibers. 7. Formwork panel according to one of the preceding claims, characterized in that that the basis weight of the reinforcement be 50 g / m² to 200 g / m² wearing. 8. Formwork panel according to one of the preceding claims, characterized in that the side ( 9 ) provided for the application of the in-situ concrete ( 18 ) of the formwork panel ( 1 ) has a shape which increases the adhesion between the formwork panel and in-situ concrete. 9. Formwork panel according to claim 8, characterized in that the side ( 9 ) of the formwork panel ( 1 ) provided for the application of the in-situ concrete ( 18 ) is provided with undercut recesses ( 10 ). 10. Formwork panel according to one of the preceding claims, characterized in that the formwork panel ( 1 ) has a thickness of at least 2 cm. 11. Formwork panel according to one of the preceding claims, characterized in that the formwork panel ( 1 ) preferably has a length of approximately 100 cm and a width of approximately 50 cm. 12. Formwork panel according to one of the preceding claims, characterized in that the formwork panel ( 1 ) on the side facing away from the in-situ concrete ( 18 ) ( 3 ) has an insulation layer ( 35 ). 13. Formwork panel according to claim 12, characterized in that the insulating layer ( 35 ) is fastened to the formwork panel ( 1 ) by means of anchoring elements ( 36 ).