DE9001679U1 - Device for releasing formwork elements - Google Patents

Description

Device 2«in releasing shielding elements

The invention relates to a device for releasing formwork elements for the production of diaphragm walls from the hardened bed.;.

It is already known that steel shuttering tubes should be used when setting up sections of a diaphragm wall that are to be concreted. The shuttering tubes are lowered into the construction joint before concreting and, in the event of a collapse, are supported against the natural soil or are supported by means of certain devices. The diameter of these shuttering tubes corresponds to the thickness of the diaphragm wall. After the concrete has set, the shuttering tubes are pulled vertically upwards out of the construction joint using hydraulic devices. In order to be able to pull the shuttering tubes out of the construction joint more easily, they are sometimes also rotated around their longitudinal axis when being pulled.

Since it is very difficult to determine the best setting time for the concrete to be pulled, it often happens that the concrete has either not yet set sufficiently or is already too hard. In the first case, parts of the freshly concreted diaphragm wall collapse when the shuttering pipes are pulled, whereas in the second case, pulling the shuttering pipes is extremely difficult and sometimes even impossible. Another disadvantage of the shuttering pipes used is that even the slightest deformation makes it impossible to pull the shuttering pipes. Another disadvantage is that shuttering pipes cannot be combined with joint tapes due to the rotational movement when pulling, since part of them remain in the concreted diaphragm wall and, due to the

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rotational movement when pulling.

It is also known to use prefabricated elements when setting up diaphragm wall sections. However, these prefabricated elements are extremely unwieldy for larger diaphragm wall depths due to their weight. In addition, such prefabricated elements are very expensive to purchase.

It is also known to detach formwork planks from the hardening concrete using a wedge-like device. Such detachment naturally occurs gradually from top to bottom.

The disadvantage of such a device, which acts as a wedge, is that in addition to the considerable effort, the time required to remove such shuttering planks is very considerable in the case of greater diaphragm wall depths and can take several hours.

It is therefore the object of the present invention to provide a device for releasing formwork elements for the manufacture of diaphragm walls from the hardening concrete, with which the release process can be made significantly easier and faster. In particular, the proposed device should make it possible to release formwork elements reliably and quickly from the hardening concrete even in the case of particularly deep diaphragm walls.

The problem is solved by the features specified in the characterising part of claim 1.

Since such formwork elements have so far been regularly released from the hardening concrete by pulling them vertically and, for reasons of space, horizontal forces could not be applied to the side of the formwork element facing away from the concrete, even though such horizontal forces would best release the formwork element, this consideration led to the use of lifting devices to apply a force between the formwork element and the diaphragm wall.

Since the diaphragm wall must be considered immovable in relation to the shuttering element,
Since the applied force is supported on the concrete diaphragm wall, the formwork element can move away from the diaphragm wall if the force is sufficient, so that it can then be easily lifted out of the diaphragm wall joint.

It is advantageous that the lifting device is arranged in recesses in the formwork element, whereby the lifting device is protected against external influences with regard to damage. This means that even concrete poured from greater heights that hits the formwork element cannot destroy the lifting device.

It is also advantageous to arrange the surface of the lifting device facing the concrete essentially in the same plane as the corresponding surface of the shuttering element and
to seal the recess as much as possible. This means that the lifting device cannot be concreted into the diaphragm wall and
After the shuttering element has been released, it may no longer be possible to remove it from the diaphragm wall. In order to avoid contamination and the lifting device being encased in concrete from behind, the lifting device is advantageously equipped in such a way that it seals the recess in the shuttering element against the ingress of concrete or concrete slurry.

It is also advantageous that the lifting device consists of lifting elements that can be operated hydraulically or pneumatically. Lifting pistons are ^the preferred lifting elements. Due to the hydraulic loading and the strength of lifting elements designed like lifting pistons, large forces can be exerted on the lifting device, so that on the one hand there is no risk of lifting elements being destroyed and on the other hand it can be guaranteed that the
The shuttering element can actually be pushed away from the tied diaphragm wall.

However, it can also be advantageous to use the lifting device in

to produce special tubular, foldable hollow bodies, which can be pressurized with gaseous or liquid media to increase their volume. In contrast to the one mentioned above, such a lifting device is considerably cheaper and is particularly suitable for diaphragm wall depths in the shorter or medium range. The tubular hollow bodies are cheap and can be easily replaced.

In order to ensure that the shuttering element can be reliably detached from the diaphragm wall, it is advantageous that the lifting device is arranged over the entire length of the surface of the shuttering element. This guarantees that reliable detachment is possible even in the deepest area of the shuttering element.

It has proven to be particularly advantageous that the lifting device is arranged over a large area and centrally on the surface of the shuttering element. Due to this proposed arrangement, the lifting device does not generate any torque in the shuttering element and is advantageously positioned on the strongest part of the shuttering element.

It is also advantageous that the lifting device consists of individual lifting devices that are distributed over the length and width of the shuttering element, whereby the individual lifting devices can also have different dimensions. This makes it possible to apply individual force to certain points on the shuttering element. A failure of one or other lifting device can also be compensated for by using several individual lifting devices, since the remaining lifting devices will usually be sufficient to reliably release the shuttering element from the diaphragm wall.

It is advantageous that the lifting device or devices can be operated via supply lines arranged inside the formwork element. This prevents the supply lines from becoming jammed somewhere in the diaphragm wall joint between the formwork element and the ground or supports.

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The advantageous possibility of operating the lifting devices individually or jointly means, on the one hand, that it is possible to work in an energy-saving manner and, on the other hand, to compensate for the failure of individual lifting devices.

It is particularly advantageous that the surface of the shuttering element facing the concrete and the corresponding surfaces of the lifting device or devices are made of concrete-repellent material and/or are treated with appropriate concrete-repellent agents before concreting. The use of the material mentioned or the treatment of the aforementioned surfaces has the advantage that the pressure applied to the lifting device or devices can be kept to a minimum, since the concrete cannot stick to the corresponding surfaces of the shuttering element or the lifting device. The shuttering element can therefore be detached from the diaphragm wall with little effort, and no damage to the diaphragm wall head occurs.

It has proven to be advantageous that the lifting distances of the lifting device or the lifting devices have a length of 1 to 15 cm. With the specified lifting distances it is guaranteed that the formwork elements can be lifted out of the diaphragm wall joint safely and reliably. Due to the relatively short lifting distances, the costs for the lifting device are reduced accordingly. In addition, simple lifting devices can also be used for shorter lifting distances.

Due to the proposed device, it is advantageously possible for the shuttering element to have a longitudinal recess on its surface facing the concrete to accommodate a joint tape. Such a joint tape, which should be arranged over the entire length of the shuttering element if possible, serves as connecting reinforcement for an adjoining section of the diaphragm wall. Such joint tapes

prevent relative movements between the individual diaphragm wall sections and in particular prevent uneven setting of the individual diaphragm wall sections. Since the proposed lifting device can also be divided into individual lifting devices, which can then be distributed as desired over the entire surface of the shuttering element, it is possible to leave a continuous longitudinal strip free on the surface of the shuttering element, into which the aforementioned recess can be inserted to accommodate a joint tape. This advantageous introduction of a joint tape into the diaphragm wall joint is not possible, for example, with the known shuttering tubes due to the rotational movement that occurs when pulling.

To ensure that the concrete or concrete slurry that has been introduced cannot penetrate into the recess provided for the joint tape in the formwork element and contaminate or clog it, the joint tape has a thickened cross-section in an advantageous design. This also ensures that the joint tape is not damaged when the formwork element is pushed away, which can happen if concrete or concrete slurry that has penetrated between the recess and the joint tape has already set.

As a rule, the formwork element is supported against the natural ground during the concreting process, i.e. the slot that is subsequently excavated for the new diaphragm wall section has not yet been created. To ensure that the existing diaphragm wall section and the subsequent excavation for the next diaphragm wall section are in line, an advantageous design provides a further recess on the side of the formwork element opposite the concrete, which extends over the entire length of the formwork element. This recess then serves as a guide for an excavation tool, which then carries out the subsequent slot excavation. If the excavation tool and its guide are inserted into the recess when the formwork element has not yet been removed, no displacement of the formwork element can occur, so that the desired alignment is guaranteed.

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However, it is also possible to insert the excavation tool guide into the recess provided for it only after the formwork element has been removed. In order to avoid displacement of the formwork element, measures may be required to prevent the formwork element from moving sideways. The desired alignment is not only necessary to maintain a specified direction. It is also necessary so that the formwork element does not get stuck on the edge of the subsequent slot created by a displacement, so that the formwork element has no room to move away from the concrete diaphragm wall. Even the slightest lateral displacement of the subsequent slot is enough to significantly hinder the removal of the formwork element or even make it impossible. The recess provided in conjunction with the excavation tool ensures that the soil in front of the formwork element is removed over the full length of the formwork element.

It is particularly advantageous that the recess tapers towards the open slot that forms on the side of the formwork element facing away from the concrete. Due to this taper, the guide of the excavation tool can be designed in such a way that, once it has been inserted into the recess from above, it can no longer leave the recess but is held in it. The excavation tool is then released either by lifting the excavation tool vertically or at specially provided points along the length of the recess, where the slot is widened accordingly.

It is also advantageous if the recess is filled with an easily deformable material before the diaphragm wall is concreted so that the recess is not blocked by gravel or concrete slurry when the diaphragm wall is concreted. During the concreting process, it is often unavoidable that gravel falls from above onto the peeling element or spreads from below.

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into the recess. The easily deformable material thus prevents clogging and, due to its consistency, does not hinder the insertion of the guide into the recess.

The invention is further described below with reference to drawings.

Fig. 1 shows a schematic cross-section through a partition element,

Fig. ? schematically a cross section through ^in formwork

element ^r.its execution type, &idiagr;

Fig. 3 shows a schematic cross-section through a formwork element, which is pushed away by the hardened concrete,

Fig. 4 schematically shows the top view of the formwork surface of a formwork element,

Fig. 5 a longitudinal section through the formwork element according to Fig. 4 in the area of the cube elements,

Fig. 6 shows a schematic cross section through a shuttering element of a further embodiment and

Fig. 7 shows a schematic cross section through a shuttering section.

element in the detachment process from hardened concrete

and with an excavator mounted at the rear- &iacgr;

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Identical reference symbols in the drawings also refer to identical parts, so that subsequent figures can be referred to previously described figures.

Fig. 1 shows a schematic cross-section of a formwork element 1 as it is arranged in the construction joint 8, transverse to its longitudinal direction, before concreting.

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On the side of the formwork element 1 facing the concrete, lifting devices are arranged, which are located in recesses 10. The lifting devices consist of foldable hollow bodies 2, such as rubber hoses or textile hoses, such as fire hoses. The lifting devices end with their surface facing the concrete with the adjacent formwork surface of the formwork iron 1, so that a flat formwork surface 5 is created. The lifting devices are powered by supply lines 6 inside the formwork element 1.

In the sealing surface 5 there is a further recess 3 running in the middle in the longitudinal direction for the detachable accommodation of a joint strip 4. The thickening in the middle of the cross section of the joint strip 4 ensures on the one hand that the joint strip 4 is securely clamped in the recess 3 during the work process and also prevents the penetration of concrete or concrete slurry into the recess 3. Likewise, the lifting devices are also sized in such a way that they prevent the penetration of concrete or concrete slurry into the corresponding recesses 10.

Fig. 2 corresponds essentially to Fig. 1, although pistons 9 are provided as lifting devices, which can be extended and retracted in a similar way to hydraulic cylinders. What was said about the hollow bodies 2 applies to their design in the retracted state according to Figs. 1 and 2, namely the formation of a flat formwork surface 5 and the prevention of contamination of the recesses 10.
The recesses 10 serve as guides for the pistons

Fig. 3 shows how the hollow bodies 2 and pistons 9 work when the formwork element 1 is to be released from the hardened concrete 7. A release force is required that relieves the adhesive stresses between the formwork element 1 and the hardened concrete 7 that arose between the formwork surface 5 of the formwork element and the concrete 7 during the setting of the concrete 7.

are, exceeds. Depending on the pressure to be applied, the pistons 9 of the lifting devices can be made of metal, plastic, rubber, wood or even concrete-like materials. Fig. 3 also shows how the detachment takes place using the lifting devices, with a gaseous or liquid medium being fed into the hose-like hollow bodies 2 via the supply line 6, which thereby increases their volume. The increase in volume of the hollow bodies 2 is caused by the folded state in which they were introduced into the recess Î&. In the case of rubber hoses, the increase in volume is also caused by the material. The pistons 9 are pressed out of the recesses 10 against the concrete 7 via the corresponding supply lines 6 in a known manner.

From Fig. 3 it can also be seen how the joint tape 4 remains in the hardened concrete 7 after the concrete 7 has hardened and the formwork element 1 has been pushed away and is released from the recess 3.

. 4 shows a view of the schematically shown formwork surface 5 of the formwork element 1 with an exemplary arrangement of different pistons 9, 9'. In the middle of the formwork surface 5 of the formwork element 1, the recess 3 for receiving the joint tape 4 can be seen, which does not extend all the way to the lower end of the formwork element 1. The arrangement shown makes it possible to guide the lower piston 9' over the middle area of the formwork surface 5 and thus to form a large area over the entire width. In this way, a central and large-area force can be applied in the foot area of the formwork element 1 during the detachment process. The pistons 9 are arranged in pairs and on both sides of the recess 3.

Fig. 5 is a schematic longitudinal section in the area of the pistons 9,9' according to Fig. 4. The supply lines 6 to «&Ggr;&Kgr;&bgr;&Pgr;&Pgr;&eacgr;&Pgr;, vjiir uic KOiucm 7, 9 ' &ngr;"&thetas;&idiagr;&Ggr;3&Ogr;&Ggr;(5&THgr;

9' is shown in the extended state. The dashed lines show the positions that the pistons 9 can reach when extended. Depending on the number of supply lines, the pistons 9,9' can be supplied separately or partially together.

Fig. 6 corresponds to Figures 1 and 2, whereby the shuttering element 1 shown differs from those previously described only in that an additional guide groove 11 is provided on the side of the shuttering element facing away from the construction joint 8 and facing the ground. The guide groove 11 is arranged approximately in the middle and extends over the entire length of the shuttering element 1.

The purpose of the guide groove 11 can be seen from Fig. 7. A guide 12 of an excavation tool is guided in it so that the subsequent construction joint runs parallel to the side surfaces of the concrete diaphragm wall, so that the soil in front of the shuttering element 1 is reliably removed. Seen in cross section, the guide groove 11 tapers in the direction of the excavation tool 13, so that a guide 12, for example, which is circular or elliptical in the end area, is held securely in the guide groove 11. Fig. 7 shows a position of the shuttering element 1 in which it has already been released from the hardened concrete 7 by means of the pistons 9. The joint tape 4 remains in the hardened concrete 7.

Claims (13)

. Device for releasing formwork elements for diaphragm wall production from hardened concrete, characterized in that that at least one lifting device is arranged on the surface of the shuttering element (1) facing the concrete (7), which, when actuated, generates forces between the shuttering element (1) and the hardened concrete (7) so that the shuttering element (1) is pushed away from the hardened concrete (7), that the lifting device consists of at least one hydraulically or pneumatically actuated piston (9,9'), which is arranged and guided in a recess (10) of the shuttering element (1), and that the surface of the piston (9,9') facing the concrete (7) in its initial position lies essentially in a plane with the formwork surface (5) of the shuttering element (1) and seals the recess (10). 2. Device according to claim 1, characterized in that that the lifting device is arranged over the entire length of the formwork surface (5) of the formwork element (1). 3. Device according to claim 1 or 2, characterized in that that the lifting device is arranged over a large area and centrally on the formwork surface (5) of the formwork element (1). I I ti* I ItIl · 1 · I &igr; · · t · It i< * t · · -13- 4. Device according to one of claims 1 to 3, characterized in that several lifting devices are provided, which are arranged distributed over the length and width of the formwork surface (5) of the formwork element (1), whereby the individual lifting devices can have different dimensions. 5. Device according to one of claims 1 to 4, characterized in that supply lines (6) arranged inside the shuttering element (1) are connected to the lifting devices. 6. Device according to one of claims 1 to 5, characterized in that the lifting devices can be loaded individually or together. 7. Device according to one of claims 1 to 6, characterized in that the formwork surface (5) of the formwork element (1) and the surfaces of the lifting devices facing the concrete (71) are made of concrete-repellent material. 8. Device according to one of claims 1 to 7, characterized in that the lifting paths of the lifting devices have a length of 1 to 15 cm. 9. Device according to one of claims 1 to 5 or 7, characterized in that the formwork element (1) for receiving a joint tape (4) has a longitudinal recess (3) on its surface facing the concrete (7). The * * - 1 10. Device according to claim 9, characterized in that the joint tape (4) has a thickening in its cross section in order to seal the recess (3) against penetrating material, in particular concrete or concrete slurry. 11. Device according to one of claims 1 to 5, 7 or 9, characterized in that the shuttering element (1) has on its side opposite the concrete a guide groove (11) which extends over the entire length of the shuttering element (1) or at least a large part thereof. 12. Device according to claim 11, characterized in that the guide groove (11) tapers in cross section in the direction of the open slot formed on the side of the formwork element (1) facing away from the concrete (7). 13. Device according to claim 11 or 1Z, characterized in that the guide groove (11) can be filled with an easily deformable material before the diaphragm wall is concreted.