WO2003046310A2

WO2003046310A2 - Permanent formwork unit

Info

Publication number: WO2003046310A2
Application number: PCT/HU2002/000133
Authority: WO
Inventors: Zoltán OZOROCZKI
Original assignee: Ozoroczki Zoltan
Priority date: 2001-11-30
Filing date: 2002-11-29
Publication date: 2003-06-05
Also published as: HU2323U; HU0100311V0; AU2002349714A1

Abstract

The invention is for a permanently installed formwork unit for reinforced concrete construction projects, consisting of two parallel, vertical, plastic, hardened foam panels, an external panel (1) and an internal panel (2), affixed securely to one another by means of vertical cross-pieces (3). The invention is characterised by the facts that its external panels (1) and internal panels (2) are of the same height and length, that their upper and lower surfaces include a series of projections (5) or matching depressions (50) used to connect the units to one another and prevent subsequent horizontal displacement, and that the cross-pieces (3), made of a fire-proof material, have rims (30) that are bent at both ends at right angles and that are pressed in to the external panel (1) and internal panel (2).

Description

PERMANENT FORMWORK UNIT

The working model described in this document is of α permanently installed formwork unit for reinforced concrete construction to be applied especially in the construction of buildings or sections of buildings. The formwork unit consists of two parallel, vertical, plastic, hardened foam panels affixed securely to one another by means of vertical cross-pieces made conveniently of a fire-proof material, such as metal or plastic.

The formwork unit represented by the working model is best used by stacking the units, then filling them with concrete, so that the formwork itself forms a layer of insulation on both sides of the wall.

Many types of permanently installed formwork have already been invented. One such solution is described as patent number 209 406. In this solution, the walls and floors are also assembled from pre-fabπcated units that are connected to one another. The formwork units in this solution also each consist of one or two layers of sheeting, separated by a series of spacers, which are arranged cross-wise with respect to the plane of the sheeting. The spacers are made of the same material as the sheeting, using the same casting technology. The essence of this solution is that it allows walls to be constructed in a manner similar to that used with traditional brick walls, by pouring concrete after the structure has been set up. The disadvantage, however, is that in practice, since the units may not be connected to one another precisely, mortar must be used at Joints, and no perfect means is given for preventing the units from sliding out of place. Also, the formwork is neither adequately ϊnsulative, nor adequately fire-proof.

Another permanently installed formwork unit s described as Hungarian patent number 40 902, where the solution consists of a water-proof box made of paper or plastic, with loadability increased by means of an insert made of the same material as the box. In practice, this solution can be used for lightening monolithic, horizontal floors or for fqshioning cavities within poured concrete, but involves the danger of the box's ..floating" to the surface of the concrete when it is poured, and thus is not reliable as a construction method. The invention can only be used, without exception, for horizontal, monolithic floors and ceilings.

Another type of permanently installed formwork is given by a Hungarian patent description published under number 45 577. There, the external and internal panelling consists of a net stretched over both a prefabricated, load-bearing iron structure and a second iron framework connected to the first, designed to distribute the load. The panelling is made stable using a reinforcing Iron structure. This method requires that a load-bearing iron framework be manufactured to size for the given site, with a netting (as thick as possible) stretched over it to take the place of the usual panelling. The disadvantage of this is that the formwork cannot be manufactured in units, so that it requires almost as much labour as conventional formwork, though with a higher probability of error.

The purpose of the present working model is to offer a permanently installable formwork unit that forms a layer of insulation on both sides of a concrete wall and thus offers heat insulation properties that are significantly better than those offered by other previously used formwork materials.

Another purpose is to offer a means for preventing the spread of fire, for obstructing penetration by various types of insects, for sound-proofing, and for attaining a high degree of static solidity. Finally, the working model seeks to offer a type of formwork that may be used in virtually any construction project for preventing heat build-up.

To meet the objectives set for this working model, we have constructed a formwork unit that consists of internal and external panels made of hardened plastic foam arranged vertically and in parallel, fixed firmly to one another by means of vertical cross-pieces, where the external and internal panels are of identical height and length, where the upper and lower surfaces of the panels are outfitted with either a series of projections, or with a matching series of depressions, the combination of which allows the units to be connected firmly together while preventing horizontal displacement, where the cross-pieces are made of a fire-proof material and possess rims at each end bent at right angles, and where said rims are pressed into the internal and external panels of the formwork.

The formwork unit represented by this working model may also be constructed such that the cross-pieces are outfitted with through-holes through their rims or lengths that allow the foam or concrete to flow through and with break-lines along their lengths, in parallel with tensile forces, that serve to reinforce them. The lengths of the cross-pieces also include cut-outs to accommodate the reinforcing steel placed within the concrete.

Another characteristic of the formwork unit represented by this working model is that the interior surfaces of its external and internal panels include vertical ridges of dovetail cross-section and uniform size at a uniform distance from one another and, as the counterforms of these rjdges, channels or grooves arranged in an alternating pattern.

Another possible construction of the formwork unit represented by the working model described in this document includes at least one hardened foam end-piece of a height identical to that of fhe panels, which can be inserted between the external and interior panels, and which also includes dovetail ridges and grooves at each of its ends that may be inserted into the dovetail ridges and grooves of the exterior and interior panels of the formwork in order to close off the unit, and whose lower or upper surfaces include either projections or depressions. In another possible construction of the formwork unit represented by the working model described in this document, the dovetail ridges described qbove are arranged on the two opposing external and internal panels at a distance apart equal to one ridge so that each ridge faces one groove, while the ridges and grooves on the two faces of the end-pieces are shifted with respect to each other by a distance equal to " ridges, so that when an end-piece is installed such that it is rotated by 180 degrees, it is shifted by a distance equal to half a ridge.

In another possible method for constructing the working model, sealing ribs are manufactured along the projections, both length-wise and cross-wise, which are shorter than the projections and connect them to each other, white sealing ridges also cross the depressions in both the length-wise and cross-wise directions.

In yet another method for constructing the working model, the cross-pieces, the dovetail ridges, the projections, the depressions, the sealing ribs, and the sealing ridges are all formed at a uniform distance from one another (such as the convenient distance of 25 mm) for the length of the formwork unit while the cross- pieces are no wider than one ridge distance for that same length.

Using one other method for consfrυcVing the working model, the exterior and internal panels are of differing thicknesses and bear cut lines on their exterior sides.

Examples of how the formwork unit may be constructed are given below in a series of drawings:

Figure 1 : Perspective drawing of the formwork unit represented by this working model. Figure 2: Top view of the formwork unit represented by this working model. Figure 3: Top view of the end-pieces of the formwork unit represented by this working model. Figure 4: Perspective drawing of one of the cross-pieces placed between the external and internal panels of the formwork unit represented by this working model, drawn schematically. Figure 5: Bottom view of the formwork unit given in Figure 1. Figure 6: Bottom view of the end-piece of the formwork Unit represented by this working model. Figure 7: Section view of the formwork unit given in Figure 2 along the line A-A. Figure 8: Section view of the formwork unit given in Figure 7 along the line B-B. Figure 9: Front view of a second possible form for a cross-piece for the working model. Figure 10: Side view of the cross-piece given in Figure 9. Figure 1 1 : Top view of the cross-piece given in Figure 9.

The formwork unit sketched in Figure 1 consists of an external panel 1 and internal panel 2, each made of hardened foam of a different thickness, which are secured to one another in parallel by means of cross-pieces 3. Heat insulation properties may be improved by making the external panel 1, which forms the wall exterior, thicker than the internal panel 2, which forms the wall interior. Horizontal displacement of the stacked units is prevented by one or more projections 5 placed conveniently along the upper surface of each panel as shown in Figure 2. The projections 5 are connected by means of sealing ribs 6. The formwork unit placed on top includes depressions 50 along its lower surface that are formed as mirror images of the projections 5. These depressions 50 are manufactured with sealing ridges 60, shown in detail in Figures 5 and 8. The projections 5 formed along the upper surface of the external panel 1 and internal panels 2 are inserted into the depressions 50 arranged as mirror images to the projections. These projections are manufactured with sealing ridges 60. In this way, the formwork units may be linked to each other and shifted with respect to each other in the length-wise and/or crosswise directions, in order that the poured cement does not leak from the stacked formwork units at their joints, sealing ribs 6 and, crossing the depressions 50 on the opposite side, sealing ridges 60, are provided. In all three drawings, the exterior surfaces of the external panel 1 and internal panels 2 have cut lines 7 placed at a convenient distance of 25 mm apart, which fortuitously corresponds to the distance between projections 5 and the distance of the ridges.

The vertical dovetail ridges 9, and grooves 8 of the interior surface of the hardened plastic foam external panel 1 and internal panel 2 hown in Figure 5 are of matching size and are displaced on the opposing side by one ridge distance. A further advantage offered by the dovetail ridges 9 and grooves 8 is that they flush with the cement in a manner resembling that of a zipper, such that afterwards the unit offers optimal adherence between concrete and hardened plastic in the area between the existing cross-pieces 3, even when one cross-piece 3 is missing.

Figures 2 and 8 show that the width of the cross-pieces 3 inside the hardened plastic foam is smaller than one ridge distance. Thus, the solution fulfils the requirement that when the unit is cut along the cut lines 7, it may not occur that the cross-pieces 3 are also cut. One great advantage in using several cross-pieces 3 in a single unit is that it prevents the hardened plastic external panel 1 and internal panel 2 from becoming displaced with respect to each other. When building formwork, therefore, the units may be cut to size without carrying out constant measurements. The cut lines 7 stand out clearly on the exterior surface of the formwork unit.

The cross-section given in Figure 8 clearly shows the cross-piece rims 30 and breaklines 32 along the lengths 34 of the cross-pieces, as well as the projections 5 and sealing ribs 6, and depressions 50 and sealing ridges 60.

Figures 3 and 5 depict the upper and lower surfaces of the end-pieces, which correspond to the upper and lower surfaces of the external panel 1 and internal panel 2. If we manufacture vertical dovetail ridges 9 and grooves 8 of uniform size and at uniform distances from each other on the internal sides of the hardened foam external panel 1 and internal panel 2, as well as the connecting end-pieces 4, the ridges 9 and grooves 8 can be used to form the ends of the walls in a construction project. Accordingly, the ridges 9 found on the end-pieces 4, which fit precisely into the grooves 8 on the external panel 1 and internal panel 2, are fashioned so that they are shifted by one ridge distance at both ends, so that the end-piece 4 can be installed precisely between the panels when the end-piece 4 is turned by 180 degrees.

Figure 4 shows the rims 30 of the cross-pieces 3 bent and right angles at their ends, and the through-holes 33 provided so that the hardened plastic foam may be better secured and hold the cross-piece 3 more solidly. The rims 30 are pressed into the external panel 1 and internal panel 2.

Figures 4 and 7 also show the breaklines 32 fashioned along the lengths 34 of the cross-pieces 3, in parallel with tensile forces, which serve to reinforce the length 34 of the cross-piece. Thus, resistance to the force exerted by the liquid concrete may be improved. The cross-pieces shown in the figure 3 are shorter than the panels. Both this convenient form and the use of through-holes 33 ensure that practically no cracking in the concrete may occur. The double-armed lengths 34 of the cross- pieces 3 ensure better distribution of the reinforcing steel, which is placed into the cut-outs 31 provided.

Professionals can easily see that the rims 30 of the cross-pieces 3, bent at right angles, are located within pressure zones inside the hardened plastic foam external panel 1 and internal panel 2. This implies that the concrete exerts an axial force on the external panel 1 and internal panel 2, and thus no breakage may occur at the cross-pieces 3.

Figure 7 shows that the hardened foam external panel 1 and internal panel 2 are straight and include no projections that would offer a convenient route for fire or sound to travel along. Thus, our solution greatly prevents the spread of fire, a property reinforced by the use cross-pieces 3 of fire-proof material. In Figures 9, 8, and 1 1 , front, side, and top views of a second possible construction of the cross-piece 3 are provided. Here, more concrete can flow between the cross- pieces 3 through an increased number of through-holes 33. The breaklines 32 serve to strengthen the lengths 34 of the cross-pieces. The cut-outs 31 in the cross-pieces 3 are fashioned to accommodate the steel used to reinforce the concrete. In this example construction, the larger number of cut-outs 31 allows for more reinforcing steel to be placed within the concrete, making it stronger and more solid. Figure 1 1 shows that the rims 30 of the cross-pieces are bent at an angle of 90 degrees on both ends.

By using a combination of the solutions presented above, it becomes possible to attain a high degree of solidity with respect to the small sizes of the fire-proof cross- pieces. In addition, the solution fulfils all other requirements specified for the formwork unit.

The figures mentioned above clearly illustrate the advantages of the formwork unit represented by this working model, which are as follows:

- The high degree of insulation offered by hardened plastic foam,

- prevention of spread of fire and penetration by various types of insects,

- a high degree of sound-proofing,

- The high degree of static solidity of the concrete,

- because of the small ridge distance, there are really no limits to what may be built with it,

- better connection between the cross-pieces and the hardened plastic foam panels,

- elimination of heat build-up with insulation of the cement. LEGEND

external panel internal panel cross-piece rim cut-out breakline thro'ugh-hole lengths of cross-piece end-piece projection depression sealing rib sealing ridge cut line groove ridge

Claims

1.) A permanently installed formwork unit for reinforced concrete construction, consisting of two parallel, vertical, hardened plastic foam panels, and external panel (1 ) and internal panel (2) , connected securely by means of vertical cross- pieces (3), characterised by the fact that the external panel (1 ) and internal panel (2) are of identical height and length, that their upper and lower surfaces are fashioned with a series of projections (5) or matching depressions (50), which allow the units to- be connected to one another, while also preventing horizontal displacement, and that the cross-pieces (3) of fire-proof material possess rims (30) bent at both ends at right angles, which are pressed into the external panel (1 ) and internal panel (2).

2.) Same as 1.) but with the characterised by that through-holes are provided on the lengths (34) of the cross-pieces (3) and/or on their rims (30), while the lengths of the cross-pieces include breaklines (32) fashioned in parallel to tensile forces and cutouts (31 ).

3.) Same as 1 .) or 2.), with the characterised by that there are vertical dovetail ridges (9) and, as the counterforms to these, grooves (8), all of a uniform size and fashioned at a uniform distance from each other, arranged in an alternating pattern on the internal surface of each external panel (1 ) and internal panel (2) .

4.) Same as l .)-3.) with the characterised by that the formwork unit includes a hardened foam end-piece (4) of a height equal to that of the panels that can be inserted between the external panel (1) and internal panel (2), that both ends are also fashioned with dovetail ridges (9) and grooves (8) that fit into the ridges (9) and grooves (8) of the external panel (1 ) and internal panel (2), thus completing the formwork unit, and that the lower and upper surfaces are fashioned with projections (5) and depressions (50).

5.) Same as 3.) or 4.) with the characterised by that the dovetail ridges (9) on the external panel (1 ) and internal panel (2) are arranged so that they are shifted by a distance of one ridge, so that each ridge (9) faces a groove (8), while the ridges (9) and grooves (8) on the two ends of the end-pieces (4) are shifted with respect to each other by on distance of 1 /2 ridges.

6.) Same as 1.)-5.) with the characterised by that sealing ribs (6) are fashioned along the projections (5) both length-wise and cross-wise such that they are lower than the projections (5) and may be used to connect the same, and also sealing ridges (60) run across the depressions (50) in both the length-wise and cross-wise directions.

7.) Same as requirements l .)-6.) with the characterised by that the cross-pieces (3), the dovetail ridges (9), the projections (5), the depressions (50), the sealing ribs (6), and the sealing ridges (60} are all formed at a uniform distance from one . another (such as the convenient distance of 25 mm) for the length of the formwork unit, while the cross-pieces (3) are no wider than one ridge distance for the same length.

8.) Same as 1 .)-8.), with the characterised by that the external panel (1 ) and internal panel (2) are of differing thicknesses and cut lines (7) are provided on the panels' external sides.