EP0673461B1

EP0673461B1 - Wall form

Info

Publication number: EP0673461B1
Application number: EP93911519A
Authority: EP
Inventors: Tarmo Mononen; Casper Aelander
Original assignee: Rautaruukki Oyj
Current assignee: Rautaruukki Oyj
Priority date: 1992-04-30
Filing date: 1993-04-29
Publication date: 1997-07-30
Anticipated expiration: 2013-04-29
Also published as: FI921984A0; AU4042093A; RU94045965A; RU2107789C1; WO1993022519A1; EP0673461A1; DE69312734D1; FI921984A7; DE69312734T2; FI91654C; FI91654B

Abstract

A wall form which comprises at minimum two oppositely placed single-use form walls (1, 2) made of profiled metal sheet and remaining a part of the final cast concrete, the first of the walls constituting the outer surface (5) of the cast concrete and the second one its inner surface (6). The wall form is made up of a plurality of vertically successive form components (10), the upper and lower edges of which have edge sections transverse to the first and second surfaces (5, 6), pointing towards the central areas of the wall and parallel to the length (L) of the component, the components (10) being stackable one on top of another to bear on the edge sections. The mainly opposite either lower and/or upper edge sections are fixedly interconnected by metal bars (3) for forming both tie members and concrete reinforcement.

Description

The invention relates to a wall form made up of a plurality of vertically adjacent form components which comprise at least two single-use form walls located in the main opposite each other and remaining part of the final cast concrete or the like, the first form wall constituting the outer surface of the cast concrete and the second one its inner surface, and, at the upper and lower edges of these form walls, edge sections transverse to the first and second surfaces and parallel to the longitudinal direction of the component, the components being stackable one on top of another to bear on these edge sections, as well as tie rods interconnecting these two form walls and inside the form reinforcement bars.
In construction and in concrete construction there is a shift being made towards industrial production methods. Thus the aim is to increase the degree of prefabrication of the building materials and to reduce the work done on site, as well as to increasingly industrialize the worksite techniques. In principle, a selection can be made between two completely different lines of action. One is the commonly known prefabricated-parts technology, in which concrete components are cast in factory conditions, are transported to the worksite, and the final structure is assembled from them on site. The second alternative is to develop in situ casting. The form systems in use have, however, been developed for conventional cast-in-situ contracting, in which case the work steps are the cleaning and assembling of the form, the installation of the form, bar placing, casting, concrete curing, stripping, and finishing work on the cast structure. Implemented in this manner, construction is not rapid, and a large amount of labor on the worksite will not result in high productivity.
For certain limited areas of use there have indeed been developed form structures in which at least some of the work steps described above can be omitted. In the main, such forms are intended for use as forms for foundations. One such arrangement, which is also applicable to other concrete casting, is disclosed in Finnish Patent 84926. In it, the form is made up of single-use form components which will remain an integral part of the cast concrete and are assembled into a form, the components comprising corrugated thin steel sheets. Such form components can, for example, be placed two opposite each other, be interconnected by means of tie rods against the casting pressure, and reinforcement bars in the necessary quantity can be placed between these components. When the arrangement according to this publication is used, it is possible to omit, of the work stages described above, the cleaning of the form, the stripping, and the finishing work on the cast structure, since the corrugated sheet constitutes the completed outer surface of the cast concrete. However, there remain the installation of the form and the placing of separate reinforcement bars in the conventional manner. There is the further disadvantage that the outer surface always has the shape of the corrugations of the corrugated sheet, which is not always suitable for all uses. Furthermore, in this structure it is very difficult to make the wall thermally insulated. The thermal insulation must either be cast in advance onto either one of the form walls, or a separate thermal insulation panel must be placed manually inside the form at the time the form is assembled, and be propped in place.
Publications US-4,297 824 US-4 348 847, US-4 149 349, DE-32 38 384, and US-3 676 967 describe connectors interconnecting the opposite face sheets of form components to be placed in succession vertically, the connectors being located at the ends of the components. Especially the first-mentioned four publications relate to those characteristics of this connector which are required for holding the insulation panel in place, i.e. the shaping of the middle part of the connector. These connectors do not, and cannot, constitute the reinforcement of the concrete. Furthermore, the connectors do not support the components against the casting pressure in the middle part of their horizontal length. US-3 676 967 does describe tie rods against the casting pressure in the middle of the sheet panels and a longitudinal reinforcing bar resting freely on end supports. This structure is very complicated to produce, gives the panels a disadvantageous non-smooth exterior surface, and according to the publication it is, nevertheless, not sufficient in a high structure. In practice, the surface sheets of the component will bulge outward in the area between the tie rods and the component ends.
The object of the present invention is to provide a wall form by means of which there are obtained, without special steps, neat and also smooth wall surfaces and in which at least part of the reinforcement constitutes a structural part of the form, in which case it need not be installed separately. An object of the invention is a wall form of this type which, without separate parts, will even in a high structure withstand without deformation the casting pressure. A further object of the invention is a wall form of this type, which, in order to facilitate installation and to avoid damage to the components, is made up of components sufficiently light in weight so that they can be handled also manually and which will not easily be deformed during handling. A further object of the invention is a wall form of this type, in which thermal insulation can be installed easily either at the time of the manufacture of the component or afterwards, in which case the thermal insulation will not require propping done manually. Furthermore, an object of the invention is a wall form of this type, in which special additional reinforcement bars can be installed in order to produce a wall structure stronger than conventional.
To eliminate the disadvantages described and to achieve the objects defined above, the invention according to the invention is characterized in what is stated in the characterizing clause of Claim 1.
The most important advantage of the invention is that it can be used for producing industrially prefabricated forms which at least in part already contain the reinforcement, the forms remaining in place after casting in situ and providing for the concrete, when necessary, a smooth surface or smooth surfaces. It is a further advantage of the invention that the assembling of the form from the components according to the invention is very simple and rapid, and in general additional work stages are hardly needed. It is a further advantage of the invention that the wall form according to it is competitive in terms of price.
The invention is described below in greater detail, with reference to the accompanying drawings.
Figure 1 depicts in general a wall form structure according to the invention, in an axonometric representation.
Figure 2 depicts a cross section, through A-A in Figure 1, of the form component according to the invention.
Figure 3 depicts a detail of the form component according to the invention, as seen from its end, from direction B in Figure 1.
Figures 4A and 4B depict two different possibilities of placing the thermal insulations in the form component according to the invention.
Figure 5 depicts, on a larger scale, the profiled surface part of the form component according to the invention, in the same representation as Figure 2.
Figures 6A and 6B depict, on a larger scale, detail C of Figure 2.
Figure 7 depicts a top view of a ladder reinforcement associated with the invention.
Figures 8A and 8B depict side and end views of a triangular reinforcement associated with the invention.
Figures 9A and 9B depict certain form components according to the invention, as seen from above, from direction D in Figures 1 and 2.
Figure 1 shows in general a wall form according to the invention, having two single- use form walls 1, 2 which will remain part of the cast concrete, the first wall constituting the outer surface 5 of the cast concrete and the second one its inner surface 6. The wall form is made up of one or several vertically stacked form components 10. Each form component 10 is thus made up of form walls 1 and 2 which constitute parts of the outer surface 5 and inner surface 6 of the entire structure. Each form wall 1, 2 is made of thin sheet, usually steel sheet, into a profiled part the length L of which is considerable and the height H of which is relatively small. The said length L may be several meters, whereas the height H of the component 10 and its thickness T, which corresponds to the thickness of the wall to be constructed, are mutually in the same order of magnitude and substantially smaller than the length L, as is evident from the figures. The height H may, of course, be clearly smaller than the thickness T, or vice versa, but both are, nevertheless, relatively small compared with the dimensions of the entire wall to be built. The wall form according to the invention is thus made up of a plurality of vertically stacked profiled form walls 1, 2, or of sheet profiles the distance between which determines the thickness T of the wall. In these form walls 1, 2 the opposite surfaces 5, 6 are generally in the main parallel, and at the upper and lower edges of a form wall there are edge sections 8a, 8b and 9a, 9b, which are each transverse to the corresponding form surface 5, 6 and point towards the central areas of the wall, for example the center line 7. In an assembled wall form these edge sections 8a, b and 9a, b are at least in their longitudinal direction approximately horizontal, as is seen in Figure 1. Thus these components 10 can be stacked vertically, since the edge sections 8a and 8b and respectively 9a and 9b on one side in vertically adjacent form components bear one on another. This can be seen in Figure 2, in which the first form component 10 has been drawn with an unbroken line and the component coming on top of it, as well as the component below it, have been drawn with a dotted line. Figure 1 for its part shows how the form components 10 have been stacked on top of the foundation 25 by using for help a guide or a corner piece 26, or corresponding components.
As an extension of the upper edge sections 8b and 9b in the form component 10 there are preferably edge folds 11 and 12, parallel to one surface 5, 6 and pointing in the same direction outward from the form component 10, as a continuation of this usually horizontal edge section. The edge folds 11 and 12 thus project, from the edge sections, approximately parallel to the surfaces 5 and 6 or slightly tilted towards the central plane 7 of the component. In the form wall 1 and 2 these edge folds 11 and 12 are at a distance of the width W1 of the lower edge section 8a and 9a from the said surface 5 or 6. In other words, the width W1 of the lower edge section, as measured from the surface 5, 6 of the component, is equal to or somewhat smaller than the distance W2 of the edge fold 11, 12 from the same surface 5, 6. This helps the form walls 1 and 2 of vertically adjacent components to align with each other during assembling, as can be understood on the basis of Figure 2.
In accordance with the invention, form component 10 is made up of two form walls 1, 2, which have been placed as mirror images of each other and are fixedly interconnected either at their upper edge sections 8b and 9b or at their lower edge sections 8a and 9a by means of metal bars 3, which are preferably of a steel bar suitable for concrete reinforcement. These steel bars 3 are fixed to the form walls 1 and 2, in which case they will constitute casting tie members resisting the casting pressure. If the height H of the components is selected to be sufficiently small, such horizontal bars 3 will be sufficiently densely located in the vertical direction, whereupon the thin sheet walls having the height dimension H will not bend. In addition, the edge sections 8a, b and 9a, b will serve as longitudinal stiffeners.
The joint between the form walls 1 and 2 and the transverse bars 3 can be made stronger, and at the same time there is obtained for the structure a longitudinal reinforcement integrated with it, by attaching the transverse bars by means of joints 15a to a longitudinal metal bar or bars 4, such as a concrete reinforcement bar, connected to the edge section by means of a joint 15b. Thereby a ladder reinforcement 18, shown in Figure 7, is produced inside the form component 10, the ladder reinforcement thus being made up of longitudinal bars 4 and of transverse bars 3 interconnecting them. This structure holds the form component very well together and at the same reinforces it. It is clear than there may be more longitudinal bars than the stated two. Both the joints 15a between the transverse bars 3 and the longitudinal bars 4 and the joints 15b between the longitudinal bars 4 and the material of the edge section are preferably welded joints 16, as is shown in Figure 6B. One or both of the joints may also be attachments implemented by means of mechanical fasteners 17, as is shown in Figure 6A.
To stiffen the form component 10 against torsion during transportation and installation, the opposite form walls 1, 2 are additionally interconnected at one or several spaced-apart points by means of approximately Z-shaped stiffening members 19. This connecting is done close to the ends of the component 10 or in the middle. The lower branch 20a and upper branch 20b of these Z-shaped stiffening members 19 extend at least approximately from one form wall to the other, and they are welded or attached in some other manner to the wall material and/or the longitudinal bars 4 or the transverse bars 3, or to their extensions. This Z-shaped stiffening member may be located in the form component in a position either perpendicular to its length L or slanted relative to it in one or several directions.
Figure 5 shows, on a larger scale, the cross section of one form wall 1, the cross section of the other form wall being its mirror image. Thus a plane of symmetry 7 is produced in the form component. In the form wall the angle K1 and K2 inside the component between the form surface 5 and 6 and the said edge section 8a and 8b or respectively 9a and 9b is somewhat smaller than 90°. In the embodiment presented, the angles K1 and K2 are in the order of magnitude of 88°. In principle it is conceivable that the upper edge section 8b and the lower edge section 8a form a wedge-like structure, in which case, for example, the upper angle K1 is clearly larger than 90° and the lower angle K2 respectively clearly smaller than 90°, but, owing to the increased load in the direction of the wall thickness, it does not seem advantageous to design this deviation to be very great.
Inside the form component 10 it is easy to place, approximately in parallel to the inner and outer surfaces 6, 5, thermal insulation panels 21 thinner than the thickness T of the wall form, either in the central area of the form component or against one form wall. These insulation panels 21 are supported by the transverse bars 3, and they are very easy to install inside the component 10 from above, either at the manufacturing plant or at the site of installation. The retention in place of the thermal insulation panels 21 can, when necessary be ensured by means of upper transverse tie members 27.
When necessary, the wall form according to the invention may include either separate concrete reinforcement bars or special reinforcement components 22, installed between the opposite form walls 1, 2 and the transverse metal bars 3. These reinforcement components 22 are, according to the invention, made up of longitudinal rods 23 preferably placed in a triangular shape and of support bars 24 installed, for example, in a zigzag manner between at least two of them and attached to them by welding, for example. Thereby a triangular reinforcement 22 is obtained, which is a very effective form of reinforcement. It is also possible to use a ladder reinforcement 18 for the vertical reinforcement.
To further improve, for example, the bond of the ladder reinforcement 18 to the form walls 1, 2, the form component can be provided with folds 13, 14 which are parallel to the form surfaces 5, 6 of the lower edge sections 8a, 9a and point towards the inner areas of the form component, as is shown in Figures 2 and 6. These folds 13, 14 thus point in the same direction as the edge folds 11, 12, and especially the ends of the transverse bars 3 or their extensions, or in this case the longitudinal bars 4 of the ladder reinforcement, will settle between these folds 13, 14 and the outer surface of the wall, thus improving the locking.
The wall form described above can be used, not only as a form for actual concrete casting as described above, but also as the form for some other setting mix to produce a corresponding wall. For temporary walls, the form space obtained with this form may also be filled with sand or gravel or the like. Such a wall can be dismantled, since the filler material can be removed.
The wall form need not necessarily be in accordance with the embodiment described above. Thus, for example, form walls 1 and 2 may have mutually different designs and dimensions. In such a case the component will not be symmetrical; the outer surface 5 and the inner surface 6 can be made different. The edge folds need not necessarily be horizontal in an installed wall form, although usually their being horizontal is advantageous and simple. In an extreme case the form components 10 may, in a manner deviating from Figure 1, be positioned upright and be pressed together horizontally by some arrangement. The form components 10 may also be curved in their longitudinal direction, in which case respectively curved walls will be obtained, as shown in Figure 9A. A form component may also be a closed circumferential component, in which case a circumferential form wall is produced, as shown in Figure 9B. The circumferential form may be a circle, an oval, a square, a triangle, or the like.

Claims

A wall form which is made up of a plurality of vertically superimposed form components (10) which comprise at least two single-use form walls (1, 2) made of profiled metal sheet and remaining part of the final cast concrete or the like, the first of the walls constituting the outer surface (5) of the cast concrete and the other one its inner surface (6) ; at the upper and lower edges of these form walls, edge sections (8a,b, 9a,b) are parallel to the longitudinal direction (L) of the component, the components (10) being stacked one on top of another to bear on these edge sections; tie members comprising transverse bars (3) fixing (15a) a pair of longitudinal spaced apart bars engaged in said opposite edge sections, said members interconnecting these two form walls; and, inside the form, reinforcement bars, characterized in that the said edge sections (8a, b; 9a, b) having essential widths (W1, W2) are transverse to the first and second surfaces (5, 6), pointing towards the central areas (7) of the wall, and the form components (10) include, as an extension of the upper edge sections (8b, 9b), edge folds (11, 12) which are approximately parallel to the first and respectively the second surface (5, 6) and point in the same direction outward from the form component (10), to provide stacking and aligning capability of the form components, and in that said longitudinal bars (4) are positioned on those surfaces of the lower edge sections (8a, 9a) which are inside the form component, the longitudinal bars being fixedly connected (15b) to said edge section, whereby said transverse and longitudinal bars (3, 4) are adapted to form both tie members and reinforcement in the final wall.
A wall form according to Claim 1, characterized in that the form components (10) include, as an extension of the lower edge sections (8a, 9a), folds (13, 14) approximately parallel to the first and respectively the second surface (5, 6) and pointing towards the inner areas of the form component, and that the bars (3) constituting the tie members, or their extensions, on the folds in opposite directions or on their parts, extend from the central areas of the form component to behind the folds in order to provide a tying of the form walls (1, 2) against the casting pressure.
A wall form according to Claim 1, characterized in that said fixed joints (15a, 15b) between the transverse and longitudinal bars and edge sections (8, 9) respectively are welds (16) and/or attachments implemented by means of mechanical fasteners (17) in order to produce a multiple-function ladder reinforcement (18).
A wall form according to Claim 1, characterized in that the two form walls (1, 2) of a form component (10) are interconnected at one point or at a plurality of spaced-apart points by means of approximately Z-shaped stiffening members (19), the lower and upper branches (20a, b) of which extend from one form wall to the other, and that the stiffening members are welded or correspondingly attached to the wall material and/or to the longitudinal and transverse metal bars (4 or 3) or to their extensions, and that the Z-shaped stiffening members (19) are at an oblique position relative to the longitudinal direction (L) of the form component (10).
A wall form according to Claim 1, characterized in that the form component (10) includes, either in its central areas or against one of the form walls, a thermal insulation panel (21), approximately parallel to the inner and outer surfaces (5, 6) and thinner than the thickness (T) of the wall form.
A wall form according to Claim 1, characterized in that this form has concrete reinforcement bars or reinforcement components (22), placed vertically between the opposite form walls (1, 2) and the transverse metal bars (3) and being preferably made up of longitudinal bars (23) placed in a triangular shape and of support bars (24) placed between at last two cf these and attached to them, in order to provide a triangular reinforcement, or which alternatively are made up of a ladder reinforcement (18) formed of longitudinal bars (4) and bars (3) transverse to them.
A wall form according to any of the above claims, characterized in that in the form component (10) the inside angle (K1, K2) of a form surface (5, 6) to an edge section (8a, b; 9a, b) is somewhat smaller than 90°.
A wall form according to Claim 1, characterized in that the form component (10) is in its longitudinal direction curved or forms a closed circumference.