Formwork element provided with sacrificial sections

Abstract

A formwork element for a molded wall panel end, 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; a form stripping assistance device cooperating with the sole plate. The form stripping assistance device 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.

Claims

1. 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; a form stripping assistance device cooperating with the sole plate; wherein the form stripping assistance device includes at least one first sacrificial section comprising a first sacrificial section first portion disposed on the first lateral zone of the inner face of the sole plate, the first sacrificial section first portion being comprised of a brittle material.

2. The formwork element according to claim 1, wherein the first sacrificial section further includes a first sacrificial section second portion disposed on the outer face of the sole plate.

3. The formwork element according to claim 2, wherein, considered in a direction transverse to the longitudinal direction, the width of the first sacrificial section first portion is greater than one-third of the width of the first lateral zone, preferably greater than half the width of the first lateral zone.

4. The formwork element according to claim 2, wherein the first sacrificial section further includes a first sacrificial section third portion disposed along the first lateral edge, the first sacrificial section third portion being fastened to the first sacrificial section first and second portions of the first sacrificial section.

5. The formwork element according to claim 4, wherein the first sacrificial section first, second and third portions form a single unitary part.

6. The formwork element according to claim 2, wherein, considered in a direction transverse to the longitudinal direction, the width of the first sacrificial section second portion is greater than one-third of the width of the sole plate.

7. The formwork element according to claim 1, wherein the first sacrificial section is comprised of a brittle material.

8. The formwork element according to claim 7, wherein the brittle material has a density comprised between 10 and 60 kg/m.sup.3, preferably comprised between 15 and 45 kg/m.sup.3.

9. The formwork element according to claim 7, wherein the first sacrificial section is made of polystyrene.

10. The formwork element according to claim 1, further including a fastening device for fastening the first sacrificial section to the sole plate.

11. The formwork element according to claim 1, further including at least one second sacrificial section including a second sacrificial section first portion disposed on the second lateral zone.

12. The formwork element according to claim 11, wherein the second sacrificial section further includes a second sacrificial section second portion disposed on the outer face of the sole plate.

13. The formwork element according to claim 12, wherein the first sacrificial section further includes a first sacrificial section second portion disposed on the outer face of the sole plate, and wherein the first sacrificial section second portion and the second sacrificial section second portion of the first and second sacrificial sections have two lateral sides, parallel to the longitudinal direction, the two lateral sides being distant from one another in a direction transverse to the longitudinal direction so as to create a longitudinal channel between the first sacrificial section second portion and the second sacrificial section second portion of the first and second sacrificial sections.

14. The formwork element according to claim 12, wherein the second sacrificial section includes a second sacrificial section third portion disposed along the second lateral edge, the second sacrificial section third portion being fastened to the second sacrificial section first and second portions of the second sacrificial section.

15. The formwork element according to claim 1, wherein the form stripping assistance device includes a plurality of first sacrificial sections disposed in the longitudinal direction.

16. A formwork system including: 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; a form stripping assistance device cooperating with the sole plate; wherein the form stripping assistance device includes at least one first sacrificial section comprising a first sacrificial section portion disposed on the first lateral zone of the inner face of the sole plate, the first sacrificial section portion being comprised of a brittle material; 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 sacrificial section portion of the first sacrificial section.

17. A form stripping method of a formwork element comprising: providing 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; a form stripping assistance device cooperating with the sole plate; wherein the form stripping assistance device includes at least one first sacrificial section comprising a first sacrificial section first portion disposed on the first lateral zone of the inner face of the sole plate, the first sacrificial section portion being comprised of a brittle material, the first sacrificial section also including a first sacrificial section second portion disposed on the outer face of the sole plate; placing said formwork element at the end of a trench filled with concrete, moving a form stripping hand along the length of the sole plate so that the form stripping hand breaks at least the first sacrificial section first portion of the first sacrificial section, and withdrawing the formwork element from the trench.

18. A method for creating a molded wall in the ground, comprising the following steps: providing 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; a form stripping assistance device cooperating with the sole plate; wherein the form stripping assistance device includes at least one first sacrificial section comprising a first sacrificial section first portion disposed on the first lateral zone of the inner face of the sole plate, the first sacrificial section first portion being comprised of a brittle material, the first sacrificial section also including a first sacrificial section second portion disposed on the outer face of the sole plate; digging a first vertical trench of rectangular cross section in the ground, the first trench having a first longitudinal end; placing said framework element in the first trench, in proximity to the longitudinal end; filling the first trench with concrete so as to form a first concrete panel; after the hardening of the first concrete panel, digging a second trench adjacent to the first trench, while cutting away the first sacrificial section second portion of the first sacrificial element; moving a first form stripping hand vertically within the thickness of the first sacrificial section first portion so as to break said first sacrificial section first portion; withdrawing the formwork element from the first trench; filling the second trench with concrete so as to form a second concrete panel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) 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:

(2) FIG. 1 is a perspective view of an embodiment of a formwork element according to the present disclosure provided with a form stripping assistance device;

(3) FIG. 2 is an exploded view of the formwork element of FIG. 1, illustrating the placement of the first and second sacrificial sections;

(4) FIG. 3 is a top view of the formwork element of FIG. 1;

(5) FIG. 4 is a front view of the formwork element of FIG. 1 which includes several form stripping assistance devices;

(6) FIG. 5 is a back view of the formwork element of FIG. 4; and

(7) FIGS. 6A to 6H illustrate the method for creating a molded wall according to the present disclosure by means of a formwork system according to the present disclosure.

DETAILED DESCRIPTION

(8) One embodiment of a formwork element 10 conforming to the present disclosure will be described by reference to FIGS. 1 to 5. As will be explained in more detail below, the formwork element 10 is intended to be disposed at one end of a vertical trench formed in the ground S. As can be noted in FIG. 1, the formwork element 10 extends in a longitudinal direction A. In operation, the longitudinal direction A is vertical.

(9) 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.

(10) The sole plate also has an inner face 20, more visible in FIG. 3, which bears a caisson 22. This caisson 22 is, in this example, welded to the inner face of the sole plate. The caisson 22 has the shape of a bell which extends in the longitudinal direction A, along substantially the entire length of the sole plate. The caisson 22 has a vertex 22a distant from the inner face of the sole plate, which comprises a seal carrier 24 to which is fastened a watertight seal 26 which extends in the longitudinal direction A of the sole plate. This watertight seal 26 has a first portion 26a which extends inside the caisson 22, and a second portion 26b which extends outside the caisson. The first portion 26a is inserted into a longitudinal slot 28 which is formed in the seal carrier 24.

(11) As can be noted in FIG. 3, the caisson 22 leaves free, on the inner face 20 of the sole plate 12, a first lateral zone 30 which is defined between the first lateral edge 4 and the caisson 22. The caisson 22 also leaves free on the inner face 20 of the sole plate a second lateral zone 32 which is defined between the second lateral edge 16 and the caisson 22. The first and second lateral zones 30, 32, also visible in FIG. 5, are parallel to the outer face 18.

(12) 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 I.sub.1, I.sub.2 of the first and second lateral zones is on the order of 37 centimeters.

(13) 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.

(14) As can be noted in FIG. 2, the first and second sacrificial sections 42, 44 have substantially the same shape and the same dimensions, so that we will limit ourselves to describing in detail the first sacrificial section 42.

(15) It is understood, by reference to FIGS. 1 and 2 that the first sacrificial section 42 comprises a first portion 50, a second portion 52, parallel to the first portion 50, and a third portion 54 which is perpendicular to the first and second portions 50, 52. Each of the first and second portions 50, 52, 54 has the shape of a plate which extends in a longitudinal direction B, which is parallel to the longitudinal direction A when the first section is mounted to the sole plate.

(16) The first portions are disposed over the first lateral zone 30 of the inner face 20 of the sole plate 12.

(17) 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.

(18) 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/m.sup.3.

(19) Furthermore, it is noted that the spacing e.sub.2 between the first and second portions 50, 52 of the first sacrificial section 42 corresponds substantially to the thickness e.sub.1 of the sole plate 12.

(20) By means of the detail of FIG. 2, it is noted that the first portion 50 has a width d.sub.1, considered in a direction perpendicular to the third portion 54. Likewise, the portion 52 has a width d.sub.2, considered in a direction perpendicular to the third portion 54. The width d.sub.2 of the second portion 52 is larger than the width d.sub.1 of the first portion 50.

(21) The width d.sub.1 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.

(22) By means of FIG. 3, it is understood that the same is true of the first portion 50′ of the second sacrificial section 44.

(23) Referring to FIGS. 3 and 4, it is noted that when the first sacrificial section is mounted on the sole plate, the second portion 52 is disposed on the outer face of said sole plate. The first sacrificial section 42 covers at least one-third of the width I of the sole plate 12.

(24) The same is true of the second portion 52′ of the second sacrificial section 44.

(25) Referring to FIGS. 3 and 4, it is noted that the second portions 52, 52′ of the first and second sacrificial sections 42, 44 have two lateral sides 52a, 52a′, which are parallel to the longitudinal direction A. These two lateral sides 52a, 52a′ are distant from one another—in a direction transverse to the longitudinal direction A—by a distance f, in this example on the order of 10 cm. This allows creating a longitudinal channel 60 between the second portions 52, 52′ of the first and second sacrificial sections 42, 44.

(26) This longitudinal channel 60 facilitates the flow of the digging mud during the placement of the formwork element in the trench.

(27) Referring again to FIGS. 2 and 3, it is noted that the third portion 54 of the first sacrificial section 42 extends along the first lateral edge 14 when the first sacrificial section 42 is mounted to the sole plate 12. In this example, the third portion is supported against the first lateral edge of the sole plate.

(28) 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.

(29) 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 sacrificial sections. As illustrated in FIG. 3, in order to protect the watertight seal 26 against crushing, it is possible to provide shims 73 disposed on either side of the seal between the caisson 22 and the straps 72.

(30) Referring to FIGS. 4 and 5, it is noted that the formwork element includes a plurality of first sacrificial sections 42 which are disposed one after the other in the longitudinal direction A, as well as a plurality of second sacrificial sections 44 which are also disposed one after the other in the longitudinal direction A. In this non-limiting example, the pluralities of first and second sacrificial sections 42, 44 are disposed end to end. By means of FIGS. 6A to 6H, an example of a method for creating a molded wall 100 in the ground S will now be described. In this example, the molded wall 100 consists of two concrete panels. Without departing from the scope of the present disclosure, the molded wall obtained by the implementation of the method according to the disclosure can obviously include additional concrete panels.

(31) These figures therefore illustrate the creation of a molded wall in top view, the plane of the sheet corresponding to the horizontal plane.

(32) In FIG. 6A, a first trench 102 is illustrated, which is dug into the ground S by means of a machine known per se, for example a rotary cutting drum cutter. Digging is carried out under mud, i.e. digging mud is injected into the trench during the accomplishment of the excavation, while pumping the mud in order to remove the fragments of excavated soil.

(33) The first trench 102 has a substantially rectangular shape which conventionally includes a first longitudinal end 104. In FIG. 6B, the first trench 102 is illustrated in which has been inserted a formwork element 10 according to the present disclosure. As is observed in FIG. 6B, the longitudinal direction of the formwork element 10 extends vertically, while the outer face 18 of the sole plate 12 is directed toward the end 104 of the first trench 102.

(34) In FIG. 6C, the first concrete panel is illustrated, obtained by filling the first trench 102 with concrete.

(35) During this step, concrete is substituted for the mud 102. Generally, and as shown schematically in FIG. 6C, it is possible for concrete to bypass the first and second lateral edges 14, 16 of the sole plate 12 to lodge between the formwork element 10 and the end 104 of the first trench 102. The thin layer of concrete which can interpose itself between the formwork element and the end 104 of the first trench 102 is labeled 106.

(36) 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 FIG. 6D, the second trench 110 is dug in the continuation of the end 104 of the first trench 102. During the digging operation of the second trench 110, the digging tool used cuts away the second portions 52, 52′ of the first and second sacrificial elements 42, 44 so that, during the digging of the second trench, the second portions 52, 52′ are destroyed and removed from the trench by pumping. There too, the digging is accomplished under mud.

(37) Then, by means of a form stripping device including a first form stripping hand 120 and a second form stripping hand 122, illustrated in FIG. 6E, a form stripping method is implemented to strip the formwork element.

(38) 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.

(39) Within the meaning of the present disclosure, the formwork element and the form stripping device constitute a formwork system.

(40) 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 FIG. 6F, is a traction movement in a direction perpendicular to the outer face 18 so as to detach the formwork element 10 from the concrete panel. This also has the effect of freeing the seal 28, the second portion 26b of which remains integral with the first concrete panel.

(41) 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 FIG. 6G.

(42) 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.