WO2010029171A1

WO2010029171A1 - Formwork for erecting building walls and method for providing the formwork

Info

Publication number: WO2010029171A1
Application number: PCT/EP2009/061867
Authority: WO
Inventors: Piero Borri
Original assignee: Piero Borri
Priority date: 2008-09-15
Filing date: 2009-09-14
Publication date: 2010-03-18
Also published as: ITAR20080028A1; IT1391906B1

Abstract

Formwork for erecting walls of buildings, comprising modular blocks (10) that have at least one metal reinforcement (2), a first part (202) of the at least one metal reinforcement (2) being arranged inside the modular blocks (10) and a second part of the at least one metal reinforcement (2) being arranged outside the modular blocks (10).

Description

FORMWORK FOR ERECTING BUILDING WALLS AND METHOD FOR PROVIDING THE FORMWORK Technical field

The present invention relates to a formwork for erecting building walls and to a method for providing it. Background Art

Formwork for erecting buildings that uses EPS modules is known. EPS, the English acronym of expanded polystyrene, is a discontinuous high-density (20-50 kg/m ) polymer, which is provided in blocks of considerable size which are cut into slabs to be sold. Thanks to its excellent thermal insulation particularities and its high soundproofing, it is a material often used in the construction sector.

Reference shall be made hereinafter in particular to modules made of EPS, but the formwork and the method for providing it described herein are to be understood as valid for any thermally insulating material.

Among formworks that use blocks of this type, a formwork is known which uses modules made of EPS whose dimensions are similar to a common brick and is provided by on-site assembly by acting first on the outer panel and then on the inner panel, once spacers of appropriate length, depending on the thickness of the wall, have been positioned. These spacers further act as a guide for the reinforcement of the wall (made of longitudinal rebars).

However, this operation is complicated and has the problem of having to provide guides on the foundation which are adapted to receive the panels, increasing laying times.

Moreover, another severe problem of this type of device is that there is a discontinuity of the wall both at the corners of the formwork and at the perpendicular joints between panels, which often causes washouts, i.e., phenomena caused by the water of the concrete that tends to escape through the gaps of the formwork due to the pressure of the casting. The most severe effect of washout is to carry away with the water also the heavier metals that are present in cements, causing a sort of erosion thereof and causing degradation of the concrete of the wall to be built.

A formwork system is available commercially which provides for shoring of the panels at the corners in order to limit washout in these regions of the formwork.

However, since in this known solution the panels are simply arranged mutually adjacent, even with this type of formwork the problem of washout between panels is not solved. Moreover, another drawback of this formwork is due to the fact that shoring of the corners is provided by means of an adapted apparatus and therefore the system is complicated and expensive.

Another type of formwork assembles the modular elements by mutually interlocking them both by means of a series of studs arranged between one course and the next and by means of an interlocking on the edges, of the male-female type.

Such formwork, however, requires very long assembly times, since laying must be interrupted every two or three courses in order to allow the placement of rebars and stirrups. Moreover, complete casting of the wall is scarcely convenient, due to the risk that the wall might encounter difficulties in being kept in a vertical position, with all the consequences in terms of times and costs that all this entails.

Another known construction system provides lattices of steel wires arranged three-dimensionally and electrically welded to each other, which form a skeleton that supports the insulating material and constitutes the formwork for the concrete casting.

This formwork has drawbacks related to the fixing of the modules, which do not always ensure co-planar walls and especially to the problem of washout, especially at corners. Accordingly, massive supporting reinforcements and a large quantity of plaster are needed. Disclosure of the Invention

The aim of the present invention is to eliminate the above-mentioned drawbacks of known types of formwork for erecting walls of civil and office buildings, by providing a method for the production of a formwork that is able to eliminate or greatly limit the phenomenon of washout, both along walls and at corners.

Within this aim, an object of the invention is to provide a formwork for erecting walls of civil and office buildings that ensures such a flatness as to eliminate all the phenomena of discontinuity among modules that are the main cause of washout and also of the onset of cracks in walls.

Another object of the invention is to provide a formwork that does not require a large number of laying operations and long assembly times, using labor-intensive processes, but allows simple and quick laying.

Another object of the invention is to reduce as much as possible the shoring of the walls in order to bear the thrust of the concrete casting, saving time and materials and providing a formwork that has a skeleton capable of supporting the walls in a vertical position.

Another object of the invention is to provide a formwork for erecting walls of civil and office buildings with means that are easily commercially available and by using commonly used materials, so that the device is economically competitive.

This aim and these and other objects which will become better apparent hereinafter are achieved by a formwork for erecting walls of buildings, comprising modular blocks that have at least one metal reinforcement, a first part of said at least one metal reinforcement being arranged inside said modular blocks and a second part of said reinforcement being arranged outside said modular blocks. Brief description of the drawings

Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of the formwork for erecting walls of buildings and of its production method, illustrated by way of non-limiting example with the aid of the accompanying drawings, wherein:

Figure 1 is a perspective view of different modular blocks for providing a formwork for erecting walls of civil and office buildings;

Figure 2 is a perspective view of two modular blocks shaped like panels, which are mutually opposite and are associated with at least one metal reinforcement, in order to provide the formwork;

Figure 3 is a sectional view of two mutually opposite panels associated with the metal reinforcement for providing the formwork;

Figure 4 is a perspective view of a modular block that is shaped like an internal corner element for providing the formwork;

Figure 5 is a sectional view of a modular block shaped like an external corner element for providing the formwork; Figure 6 is a perspective view of an external corner element for providing the formwork;

Figure 7 is a perspective view of a modular block that is shaped concordantly with one of the closing elements for providing the formwork;

Figure 8 is a sectional view of one of the closure elements for providing the formwork;

Figure 9 is a view of a portion of the formwork comprising panels associated with corner elements;

Figure 10 is a sectional view of a portion of the formwork comprising panels which are mutually associated and plugged by closure elements; Figure 11 is a sectional view of the formwork prior to the casting of a first amount of concrete. Ways of carrying out the Invention

With reference to the figures, a formwork for erecting walls of buildings, according to the invention, generally designated by the reference numeral 1, can comprise modular blocks 10, which have at least one metallic portion 2, referenced in the text by the term "reinforcement".

The metal reinforcement 2 comprises at least one part 202 which is internal to the blocks 10 and is inserted subsequently or provided monolithically. In the embodiment described here, the metal reinforcement 2 can be provided by means of a metallic net, preferably made of steel.

The blocks 10 are normally made of thermally insulating synthetic material, preferably EPS.

Advantageously, the modular blocks 10 can comprise at least one male element 101 and at least one female element 102.

These male and female elements are such that the male element 101 of a first modular block can be mated with the female element 102 of a second modular block.

Preferably, the male element 101 has a protrusion which has a semicircular cross-section, while the female element 102 has a recess with the same semicircular shape.

In the embodiment described here, the internal part 202 is straight with respect to the longitudinal direction of the blocks 10.

Advantageously, the metal reinforcement 2 can comprise a folded part 201 , which is external to the blocks 10, and means for mutual connection among the modular blocks 10.

The folded part 201 preferably has an aperture angle of approximately 45°, so that the modular repetition of the metallic portions 2, mutually associated by way of said connecting means, gives rise to a honeycomb structure.

These connection means comprise a pair of tubular elements 203, each of which is fixed at the folded part 201 of the metal reinforcement 2 of two distinct modular blocks 10, and a connector 204, which engages simultaneously the pair of tubular elements 203. In this embodiment, the connector is a U-shaped rebar. Advantageously, the modular blocks 10 can comprise panels 1 1 in which the male elements 101 and the female elements 102 are on two mutually opposite lateral faces.

Advantageously, the blocks 10 can also comprise internal corner elements 12 and external corner elements 13.

The corner elements 12, which normally have a square base, can have the male elements 101 and the female elements 102 on two adjacent lateral faces.

The external corner elements 13, whose cross-section resembles the letter L, can have the male element 101 and the female element 102 in the faces that correspond to the shorter sides of the L-shape and can comprise a corner connection 21 for engagement with the metal reinforcement 2.

Preferably, the corner connection 21 comprises:

- a central region 210, which is partially inserted in the insulation of the corner element 13;

- two metal flaps 211, in which a first edge is associated with the central region 210 and a second edge is internal to the corner element 13;

- a second tubular element 212, which mates with a second engagement connector 213 for the two flaps 21 1. In the embodiment described herein, the part that is not inserted in the corner element 13 of the central region 210 has a longitudinal direction that is substantially oriented toward the inside of the formwork; in particular, in the direction of the bisecting line of the angle formed by the corner element 13. Moreover, the longitudinal direction of the flaps 21 1 is substantially perpendicular to the longitudinal direction of the central region 210.

The second tubular element 212 can have its axis arranged on the connecting line between the central region 210 and each of the two flaps 21 1 ; the engagement between the connector 213 and the two flaps 21 1 is similar to what has been shown for the connections between the folded parts 201 of two metallic portions 2, as described earlier. Preferably, rebars 23 are provided, which have a head 231 for engagement with each second tubular element 212 of the corner connection

21 and at least one hook-shaped end 232 for hooking onto the pair of tubular elements 203 of the nearest metal portions 2, so as to fix the corner element 13 to said metal reinforcement.

In order to plug the structure at the sides of doors and windows, the blocks 10 can also comprise at least one closure element 14.

Advantageously, the closure element 14 can have a quadrangular base with a pair of sides that have the same length as the final thickness of the wall to be provided. It can further comprise both the male element 101 and the female element 102 in the internal side 141 with respect to the formwork, so as to constitute a plug for such formwork. Finally, there can be an anchoring element 22 for the connection of the closure element 14 to the reinforcement 2. The anchoring element 22 can have:

- a central part 221 for supporting a pair of metal sheets 225 that is partially internal with respect to the insulation of the closure element 14;

— two supporting wings 222, which are connected to the central part 221 and are internal with respect to the closure element 14; - a hook 223.

In the embodiment being described, the hook 223 is T-shaped and engages, at one of its ends, at least one hole 224 provided in the central part 221 , which is triangular, and is fixed at the other end on the connecting element 204. Finally, it is possible to provide the formwork 1 with a per se already known footing 3 to aid the stability of the metal portions 2.

The method for assembling the formwork 1 for erecting walls of buildings comprises the following steps, which will be listed hereafter.

The perimeter of the building is delimited by arranging the modular blocks 10, placing the panels 1 1 so that a first panel 11 1 is in front of another opposite panel 1 12, creating a gap 4 which in the end will be filled with the concrete casting.

A third panel 1 13 is then moved toward the first panel 1 1 1 or toward the panel 112 that lies opposite the first one, so as to mutually mate the respective male element 101 and female element 102.

Then the metal portions 2 of the respective panels are mutually engaged in pairs by way of the connecting means already described.

The angular elements 12 and 13 are used to provide the corners of the building. Therefore, the internal corner elements 12 are inserted so as to mutually join a first internal panel 114 and a second internal panel 1 15, taking care to mate the male element 101 of the first internal panel 114 with the female element 102 of the corner element 13 and the male element 101 of the corner element 13 with the female element 102 of the second internal panel 1 15.

In order to assemble the external corner elements 13 and join a first external panel 1 16 to a second external panel 117, in a manner similar to what has been done for the internal corner elements, the male element 101 of the first external panel 1 16 is mated with the female element 102 of the corner element 13, and the male element 101 of the corner element 13 is mated with the female element 102 of the second external panel 1 17.

Then the corner connection 21 is engaged with the metal reinforcement 2: this connection 21 makes the corner element 13 stable thanks to the connector 213. In order to jointly fix the corner elements 13 to the metal reinforcement 2, the rebars 23 are then used and are fitted so that they are fixed to the second connector 213 with the engagement head 231 and to the connector element 204 with the hook-shaped end 232.

The structure is still incomplete, but the casting of a first amount of concrete is performed by pouring it into the provided formwork by using the still-open side of the structure: i.e., by passing the casting pipes through the open sides of the formwork, where, when the structure will be finished, the jambs of doors and windows will be installed.

As pouring proceeds, the formwork is plugged at least partially with the closure elements 14, which join a first end panel 118 and a second end panel 1 19, mating the male element 101 and the female element 102 on the inner side 131 of the element 14, respectively with the female element 102 of the panel 1 18 and the male element 101 of the panel 1 19.

The connection between the T-shaped hook 223 of the anchoring element 22 and the metal portions 2 of the panels 1 1 is then performed and jointly fixes said closure element to the reinforcement 2.

Finally, once the provision of the perimetric walls has been completed, the structure is closed by resting the floor slabs on the formwork. Once the concrete casting within the formwork has been completed, the metal portion 2 constitutes the reinforcement of the building.

From what has been described above it is therefore evident that the invention achieves the proposed aim and objects, and in particular the fact is stressed that a formwork for the erection of walls of civil and office buildings and a method for its production are provided which eliminate washout phenomena both along walls and at corners.

In particular, the provision of couplings of the modular blocks of the male-female type greatly limits the discontinuities of the walls to be provided, ensuring excellent co-planarity, which prevents the formation of cracks in the plaster and most of all eliminates washouts.

Moreover, washouts are eliminated completely thanks to the provision of corner elements that can be mated with the panels and bear the thrust of the concrete casting without the need for important shoring.

Another advantage of the invention resides in that closure elements have been conceived which plug the walls at the sides of doors and windows, allowing to pour the concrete even from levels that are intermediate with respect to the height of the wall thanks to the partial plugging of the sides.

Another advantage of the formwork according to the invention is that it eliminates any thermal bridge, since the ends of the metal reinforcement 2 of the wall are embedded in the insulation.

Another advantage of the device resides in the shape of the elements that can be mated, of the male-female type, which have a semicircular cross- section that facilitates the pairing of the modules without creating fragile points.

Another advantage of the invention is that with the absence of fragile points and with the elimination of washout phenomena, it is possible to erect buildings adapted to be built in seismic regions.

Another advantage of the formwork according to the invention resides in that the provision of such perimetric walls simplifies the placement and installation of the floor slabs needed to close the building.

Another advantage is that the method for assembly of the formwork is simple to provide and requires limited labor, and this, thanks to the use of materials that are used normally and of means that are easily commercially available, makes the device according to the invention commercially convenient.

In practice it has been found that the invention thus described allows to provide a formwork for the erection of walls of civil and office buildings that is extremely functional, allows easy assembly and ensures excellent support for the thrust of the concrete casting, greatly limiting washout phenomena.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. All the details may further be replaced with other technically equivalent elements.

In practice, the materials used, as well as the dimensions, may be any according to requirements so long as they are consistent with the constructive aim and objects. The disclosures in Italian Patent Application No. AR2008A000028 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A formwork for erecting walls of buildings, comprising modular blocks (10) that have at least one metal reinforcement (2), characterized in that a first part (202) of said metal reinforcement (2) is arranged inside said modular blocks (10) and a second part of said metal reinforcement (2) is arranged outside said modular blocks (10).

2. The formwork according to claim 1, characterized in that said modular blocks (10) comprise at least one male element (101) and at least one female element ( 102), said at least one male element (101) of a first modular block providing mating for said at least one female element (102) of a second modular block.

3. The formwork according to claims 1 or 2, characterized in that said at least one metal reinforcement (2) comprises at least one folded part (201 ) in its outer part and means for connection between said modular blocks (10).

4. The formwork according to claims 1 and 3, characterized in that said connection means comprise a pair of tubular elements (203), each of which is fixed to the intersection of said at least one folded part (201) of two distinct said modular blocks (10) and a connector element (204) which engages said pair of tubular elements (203).

5. The formwork according to claims 1 and 2, characterized in that said modular blocks (10) comprise panels (11) which have said at least one male element (101) and said at least one female element (102) each arranged in mutually opposite lateral faces.

6. The formwork according to claims 1 and 2, characterized in that said modular blocks (10) comprise at least one internal comer element (12) provided with said at least one male element (101) and said at least one female element (102), in at least two of its mutually adjacent lateral faces.

7. The formwork according to claims 1 and 2, characterized in that said modular blocks (10) comprise at least one external corner element (13), provided with said at least one male element (101) and said at least one female element ( 102) in at least two of its lateral faces and supports at least one corner connection (21) for engagement with said at least one metal reinforcement (2).

8. The formwork according to claim 7, characterized in that said corner connection (21) comprises a central region (210), which is inserted partially in said at least one external corner element (13), metal flaps (21 1) which have a first edge associated with said central region (210) and a second edge which is internal to said at least one external corner element (13), and a second tubular element (212) for mating with a second connector (213).

9. The formwork according to claims 1 and 2, characterized in that it comprises at least one closure element (14), which has a lateral face that has at least the same length as the final thickness of the wall to be provided, and further having said at least one male element (101) and said at least one female element (102) on the inner side (141) with respect to said formwork, and provided with an anchoring element (22) for connection to said at least one metal reinforcement (2).

10. The formwork according to claim 9, characterized in that said anchoring (22) comprises a central supporting part (221 ) for a pair of metal sheets (225), which is partially internal to said at least one closure element (14) and has at least one hole (224), two supporting wings (222) connected to said central part (221) which are internal to said closure element (14) and a hook (223) which engages, at one of its ends, said at least one hole (224) and is fixed, in its other end, to said connecting element (204).

1 1. A method for providing a formwork for erecting walls of buildings, comprising the steps that consist in:

- arranging side by side at least one external sequence and at least one internal sequence of modular blocks (10), supported by at least one metal reinforcement (2) that is inserted partially inside them, said sequences forming a gap between mutually opposite panels (11), through which portions of said metal reinforcements (2) protrude; - mutually engaging a plurality of mutually opposite metal reinforcements

(2); - performing a first pouring of concrete within said gap.