Patent Application
20210363720
The present disclosure relates to a formwork element for a molded wall panel.
In known fashion, when it is desired to make a molded wall, i.e. a wall made of concrete in a trench dug into the ground, this operation is carried out in successive slices, each corresponding to a molded wall panel, the panel assembly constituting the wall.
To ensure the mechanical continuity of the panels of the wall in the connection zone between two panels, a particular shape is given to the end of each panel, which allows the embedding of one end of a panel in the end of the preceding panel. This shape is obtained by means of a formwork element which generally includes a seal. More precisely, this formwork element is place at one end of the trench, before the concreting of said trench.
The present disclosure relates more particularly to a formwork element for a molded wall panel end, said formwork element extending in a longitudinal direction and comprising:
a sole plate having a first lateral edge, a second lateral edge, an outer face, an inner face bearing a caisson, said caisson leaving free, on the inner face of the sole plate, a first lateral zone, defined between the first lateral edge and the caisson, and a second lateral zone, defined between the second lateral edge and the caisson.
The first lateral edge is therefore disposed between the outer face and the inner face bearing the caisson.
One known problem is that, during the concreting step, the concrete has a tendency to bypass the formwork element. After hardening, the concrete adheres to the formwork element, which makes its extraction from the trench difficult.
To solve this problem, EP 1 039 038 teaches the use of a form stripping assistance device cooperating with the sole plate.
This form stripping assistance device consists of sacrificial rectangular elements which are disposed along the lateral edges of the sole plate, the lateral edges consisting of the end edges of the sole plate.
To accomplish form stripping, it is known to use a form stripping device, known per se, provided with form stripping hooks which are moved along the first and second lateral edges to detach the formwork element from the concrete.
If the rectangular elements described in EP 1 039 038 give complete satisfaction for trenches of small and medium depth, the inventors have noted that they were less effective for trenches of great depth, i.e. more than 40 meters.
One aim of the present disclosure is to propose a formwork element allowing the facilitation of the step of stripping forms after concreting.
To this end, the form stripping assistance device of the formwork element according to the present disclosure includes at least one first sacrificial section comprising a first portion disposed on the first lateral zone of the inner face of the sole plate.
The first portion is therefore a first sacrificial section portion which extends over the first lateral zone of the inner face of the sole plate, between the first lateral edge and the caisson. The first lateral zone is substantially parallel to the outer face.
The first sacrificial section also extends in the longitudinal direction of the sole plate.
The first portion, which may extend in the longitudinal direction of the sole plate, may allow avoiding having the concrete adhere to the inner face at the first lateral zone. In the absence of a first sacrificial section within the meaning of the present disclosure, the first lateral zone of the inner face has a large adhesion surface with the concrete, which may make disengagement of the formwork element difficult. The first sacrificial portion, which is destroyed during the passage of the hooks of the form stripping device, may have the effect of preventing, or at the very least substantially limiting, the adhesion of the concrete to the first lateral zone, which consequently facilitates the subsequent disengagement of the formwork element.
The first portion may have a width, considered in a direction transverse to the longitudinal direction of the formwork element, which is greater than one-third of the width of the first lateral zone. The width of the first portion may be greater than half the width of the first lateral zone. Additionally, the first portion may extend substantially until the caisson. One benefit may be to be able to cover the largest possible surface at the internal face of the sole plat in order to facilitate the subsequent form stripping of the formwork element.
To accomplish the form stripping of the formwork element according to the present disclosure, a form stripping device provided with a first hook formed to engage between the concrete and the inner face of the sole plate may be used, within the thickness of the first portion, so as to be able to destroy the first portion of the first sacrificial section during the vertical movement of the form stripping device.
The first sacrificial section may also include a second portion disposed on the outer face of the sole plate. The second portion is a second sacrificial section portion.
The Inventors have noted, moreover, that during concreting of a trench of great depth, the concrete can have a tendency to bypass the sole plate and come into contact with its outer face. After hardening and in the absence of a form stripping assistance device according to the present disclosure, the concrete may then adhere to the sole plate and make withdrawal of the form stripping element from the trench difficult.
The second portion may allow prevention of the concrete, having bypassed the first lateral edge of the sole plate from adhering to the outer face of the sole plate. Thanks to the technology of the present disclosure, the concrete which bypasses the first lateral edge of the sole plate would, at most, adhere against the second portion of the first sacrificial element. This second portion, to which the concrete may possibly have adhered, can then be destroyed during subsequent digging of the adjacent trench. The excavated fragments of concrete and of the second portion can then be removed by pumping during the excavation of the adjacent trench. This may have the effect of reducing the adhesion between the concrete and the sole plate, which may facilitate the subsequent extraction of the formwork element from the trench.
Considered in a direction transverse to the longitudinal direction, the width of the second portion may be greater than the width of the first portion. One benefit may be to cover a surface of the outer face which is greater than the surface of the first lateral zone.
Additionally, the thickness of the second portion may be substantially equal to the thickness of the first portion.
The first sacrificial section may also include a third portion disposed along the first lateral edge, the third portion being fastened to the first and second portions of the first sacrificial section. The third portion is a third sacrificial section portion.
The third portion may have the effect of preventing the concrete from adhering to the first lateral edge. It may also facilitate the engagement of the form stripping hands.
The first form stripping hand of the form stripping device may be formed to move vertically within the thickness of the third portion, which may have the effect of destroying the third portion during the vertical movement of the form stripping device. This may allow detaching the first vertical edge of the concrete, and consequently, possibly facilitating the withdrawal of the formwork element from the trench.
The first, second and third portions may form a single unitary part.
The first sacrificial element may therefore be one-piece. One benefit may be to be able to easily and rapidly assemble the first sacrificial element to the sole plate. This may also facilitate the manufacture of the first sacrificial element.
The thickness of the third portion may be substantially equal to the thickness of the first portion.
Additionally, the distance between the first and second portions may be substantially equal to the thickness of the sole plate.
It will therefore be understood that the first sacrificial element may clasp the first lateral edge of the sole plate, which may allow prevention of the concrete from adhering to the sole plate.
Considered in a direction transverse to the longitudinal direction, the width of the second portion may be greater than one-third and less than half the width of the sole plate. One benefit may be to leave a passage for the flow of mud during the placement of the formwork element in the trench.
The first sacrificial section may consist of a brittle material, so that it can easily be destroyed or shredded by the form stripping device. It is also understood that the first sacrificial section, for example the second portion, is destroyed during the digging of the adjacent trench.
The brittle material may have a density comprised between 10 and 60 kg/m3, possibly comprised between 15 and 45 kg/m3.
The first sacrificial section may be made of polystyrene.
In other words, at least the first section may consist of a brittle material, polystyrene for example.
The formwork element according to the present disclosure may also include a fastening device for fastening the first sacrificial section to the sole plate.
The fastening device may include one or more slender elements, such as wires, straps or small cross-section cables, which clasp the formwork element in order to hold the first sacrificial section with the sold plate during the introduction of the formwork element into the trench and during concreting. Shims may be disposed between the caisson and the slender elements in order to avoid crushing of the seal. The fastening devices may be dimensioned to be split during the passage of the form stripping device or during the digging with mud of the adjacent trench. The residues are removed from the trench by pumping or by a skip during the excavation of the adjacent trench.
The fastening device may also include a holding device to hold the first sacrificial section against the outer face of the formwork element. The fastening device may consist of a brittle or splittable material. This holding device may comprise one or more plates, of wood for example, extending along the second portion.
The holding device may include a spacer portion to maintain a longitudinal space between two adjacent formwork elements. One benefit may be to ensure the alignment of the sections while reducing the necessary quantity of polystyrene.
The fastening device may include at least one breakable rod which passes through and holds the sole plate in a sandwich together with the first and second portions of the first sacrificial section, the rod extending perpendicular to the outer face of the sole plate.
The formwork element may also include at least one second sacrificial section including a first portion disposed on the second lateral zone.
It is therefore understood that the first portions of the first and second sacrificial sections may extend on either side of the caisson, for example in the longitudinal direction of the formwork element.
The second sacrificial section may also include a second portion disposed on the outer face of the sole plate. The second portion of the second sacrificial section may be identical to the second portion of the first sacrificial section.
The second portions of the first and second sections may cover at least two-thirds of the width of the outer face.
The second portions of the first and second sacrificial sections may have two lateral skies, parallel to the longitudinal direction, the two lateral sides being spaced from one another in a direction transverse to the longitudinal direction so as to create a longitudinal channel between the first and second sacrificial sections.
This longitudinal channel may therefore be delimited between the two lateral sides and the outer face. It may allow the flow of mud during the placement of the formwork element in the trench.
As disclosed above, the second portions may be destroyed during the digging of the adjacent trench and removed from the trench by pumping.
The second sacrifidal section may include a third portion disposed along the second lateral edge, the third portion being fastened to the first and second portions of the second sacrificial section. The second sacrificial portion may be one-piece.
The second sacrificial section may be identical to the first sacrificial section, the first and second sacrificial sections extending on either side of the caisson.
The form stripping assistance device may include a plurality of first sacrificial sections disposed one after the other in the longitudinal direction of the formwork element.
The first sacrificial sections may extend over substantially the entire length of the sole plate.
In known fashion, the formwork element may also include a seal which is fastened to the caisson. The seal has a first portion initially disposed at the inside of the caisson and a second portion extending outside the caisson. The seal is substantially perpendicular to the outer face of the sole plate. The second portion of the seal is engaged with the concrete of the first panel after hardening. During withdrawal of the formwork element from the trench, the seal remains in the trench integral with the first panel, the first portion then extending into the adjacent trench.
The present disclosure also relates to a formwork system including a formwork element according to the present disclosure, and a form stripping device including at least one first form stripping hand configured to be moved longitudinally along the first lateral zone of the inner face of the sole plate so as to break at least the first portion of the first sacrificial section.
The form stripping device may be mounted at the end of a digging tool, a skip for example.
The form stripping device may include a second form stripping hand, symmetric with respect to the first form stripping hand, so as to destroy simultaneously the first portions of the first and second sacrificial sections during the vertical movement of the form stripping hands.
The form stripping device may also comprise a movement device for moving the first form stripping hand vertically in the trench along the two lateral skies of the sole plate.
The present disclosure also relates to a form stripping method of a formwork element according to the present disclosure, said formwork element being placed at the end of a first trench filled with concrete, method in which, after hardening, a form stripping hand is moved along the length of the sole plate so that the form stripping hand breaks at least the first portion of the first sacrificial section, then the formwork element is withdrawn from the trench.
Optionally, before movement of the form stripping hand, a second trench may be dug under mud adjacent to the first trench while cutting away the second portions of the first and second sacrificial sections, the segment fragments then being removed by pumping or by the skip during the excavation of the adjacent trench.
Finally, the present disclosure relates to a method for creating a molded wall in the ground, comprising the following steps:
The present disclosure will be better understood upon reading the description that follows of an implementation method given by way of a non-limiting example, with reference to the appended drawings, in which:
One embodiment of a formwork element 10 conforming to the present disclosure will be described by reference to
The formwork element 10 includes a sole plate 12, preferably made of steel, which has a first lateral edge 14 and a second lateral edge 16, the first and second lateral edges 14, 16 also extending in the longitudinal direction A. Furthermore, the sole plate 12 has an outer face 18 which is planar. In this example, the sole plate has a length of 700 cm and a width of 144 cm. The outer and inner faces are substantially parallel.
The sole plate also has an inner face 20, more visible in
As can be noted in
In this example, the first and second lateral zones 30, 32 are planar and extend in the longitudinal direction A. The width I of the sole plate, considered in a direction transverse to the longitudinal direction A, is on the order of 144 centimeters, while the widths I1, I2 of the first and second lateral zones is on the order of 37 centimeters.
According to the present disclosure, the formwork element 10 also includes a form stripping assistance device 40 which cooperates with the sole plate 12. This form stripping assistance device 40 includes a plurality of first sacrificial sections 42, as well as a plurality of second sacrificial sections 44. The first and second sacrificial sections, when they are mounted on the sole plate, extend in this example in the longitudinal direction of said sole plate.
As can be noted in
It is understood, by reference to
The first portions are disposed over the first lateral zone 30 of the inner face 20 of the sole plate 12.
In this example, the first, second and third portions form a single part. In other words, the first sacrificial section 42 is one-piece. The same is true of the second sacrificial section 44.
In this example, the first sacrificial section 42 consists of a brittle material, in this example, it is polystyrene, the density of which is comprised between 15 and 45 kg/m3.
Furthermore, it is noted that the spacing e2 between the first and second portions 50, 52 of the first sacrificial section 42 corresponds substantially to the thickness e1 of the sole plate 12.
By means of the detail of
The width d1 of the first portion 50 is configured in such a manner that, when the first sacrificial section 42 is mounted on the sole plate 12, the first portion 50 covers the first lateral zone 30.
By means of
Referring to
The same is true of the second portion 52′ of the second sacrificial section 44.
Referring to
This longitudinal channel 60 facilitates the flow of the digging mud during the placement of the formwork element in the trench.
Referring again to
Likewise, the third portion 54′ of the second sacrificial section 44 is disposed along the second lateral edge 16 when the second sacrificial section is mounted on the sole plate 12.
To retain the first and second sacrificial sections 42, 44 with the sole plate 12, the formwork element 10 also includes a fastening device 70, which, in this example, appears in the form of straps 72 which clasp the sole plate, the caisson and the sacrificial sections. In the example illustrated, two straps 72 have been provided to retain a pair consisting of a first sacrificial section and a second sacrificial section. Naturally, without departing from the scope of the present disclosure it is possible to provide a different number of straps, particularly depending on the length of the sacrifidal sections. As illustrated in
Referring to
These figures therefore illustrate the creation of a molded wall in top view, the plane of the sheet corresponding to the horizontal plane.
In
The first trench 102 has a substantially rectangular shape which conventionally includes a first longitudinal end 104. In
In
During this step, concrete is substituted for the mud 102. Generally, and as shown schematically in
After the hardening of the first concrete panel, a second trench 110 is dug adjacent to the first trench 102. As can be understood by means of
Then, by means of a form stripping device including a first form stripping hand 120 and a second form stripping hand 122, illustrated in
Considered in a substantially horizontal plane, each of the first and second hands has the shape of a hook composed of a first part and a second part perpendicular to the first part. The first part is configured to engage in the thickness of the first portion 50, while the second part is configured to engage in the thickness of the third portion 54.
Within the meaning of the present disclosure, the formwork element and the form stripping device constitute a formwork system.
To this end, the first and second form stripping hands 120, 122 are lowered vertically along the first and second lateral zones of the sole plate 12 from the ground surface, so as to engage in the thickness of the first and third portions, this in order to break said first and third portions of the first and second sacrificial sections 42, 44. The passage of the first and second form stripping hands 120, 122 over the inner face of the sole plate is facilitated by the presence of the first portions 50, 50′ of the first and second sacrificial sections 42, 44 which are rapidly shredded during the movement of the first and second form stripping hands. Also accomplished, as illustrated in
The formwork element is then withdrawn from the ground, so that the mud fills the space which was previously occupied by the formwork element 10, as illustrated in
Then, the second trench 104 is filled with concrete so as to obtain, after hardening, a second concrete panel. Thus a molded wall is obtained consisting of the first and second adjacent concrete panels. It is noted that the first portion 28a of the seal 28 engages with the hardened concrete of the second portion 104, in order to form the watertight seal between the two concrete wall elements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1855779 | Jun 2018 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2019/051578 | 6/26/2019 | WO | 00 |
