Formwork sleeve

Abstract

A formwork sleeve for creating at least partial formwork around an installed pipe is shown, enabling the filling of a material, in particular concrete or plaster, around the pipe in the area of ​​a pipe penetration. The formwork sleeve comprises a gas-fillable inflatable body, a pipe penetration opening in which a section of the pipe can be arranged so that the formwork sleeve extends around the pipe section, a separation point extending from an outer surface to the penetration opening, and a gas inlet for pressurizing the formwork sleeve with gas. The formwork sleeve is designed to seal around the pipe and the pipe penetration when inflated, and an upper surface of the formwork sleeve forms a receiving surface for the filling material.

Description

Field of invention

[0001] The present invention relates to a formwork sleeve that can be attached around pipes, in particular sewage pipes, to make it easier to plaster or encase these pipes in concrete, and to a method for using a formwork sleeve. Background and general description of the invention

[0002] In the construction and building services sector, wall or ceiling penetrations are frequently required to install pipes, cables, or conduits. This applies equally to new construction projects for the installation of new pipes and to existing buildings where new pipes need to be laid or existing pipes replaced. These penetrations can either be pre-existing openings or, especially in existing buildings, are created by cutting the wall or ceiling to allow pipes to run from one room to an adjacent room or from one floor to another.

[0003] Once the pipework is complete, the area between the pipe and the existing masonry or ceiling section must be filled. Typically, the plasterer is only called to the site once the (sewage) pipe is fully installed. This usually means there's no opportunity to cut the pipe at any point. In any case, it can be advantageous to encase the pipe directly in the filler material.

[0004] Up to now, these openings have been laboriously sealed before being filled, for example with wooden boards and packing materials, which can take many hours for ceiling and wall penetrations. Depending on the opening, additional sealing materials such as PU foam or silicone sealant may also be required to improve watertightness. This further increases the workload and makes removing the formwork more difficult after filling. After installing conventional formwork, for example for the ceiling, it must first be tested to ensure that the formwork is watertight. The use of liquid concrete, for example, is only possible once it has been confirmed that everything is watertight. For this purpose, a quick-setting concrete (five-minute concrete) may be used first, a small amount of which is poured onto the formwork from above, initially filling and sealing any potential leaks.Instead of rapid-setting concrete, foam concrete can also be used here, which expands after being poured and thus acts as both a sealant and filler. If concrete drips onto the floor, splashes can cause significant contamination in the floor below.

[0005] German patent application DE 10 2021 110 408 A1, which describes a development by the same inventor that also describes the present invention, has already addressed this problem to some extent and shows a reusable formwork sleeve, also for the purpose of filling an area around a pipe with a filling material, requiring less rigid formwork than in known wooden formwork. In that case, an elongated body is wrapped around the pipe, secured with a strap, and then inflated to form formwork.

[0006] In contrast, DE 10 2021 102 201 A1 shows a formwork element that is embedded in the concrete and can be used as a walking surface after the concrete has hardened. This represents a fundamentally different application. Formwork in the area of ​​a pipe penetration is not provided.

[0007] German patent application DE 2 221 653 discloses a reusable formwork hollow body for the in-situ production of concrete pipes at the construction site. The formwork serves a fundamentally different purpose and also has a different structure.

[0008] The present invention therefore aims to provide a device by means of which the process of sealing and encasing pipe penetrations can be significantly accelerated and / or simplified. In a further development, it should provide a flexible and tight seal without the need for additional sealing agents such as PU foam or silicone.

[0009] In further developments of the invention, the device is designed to be reusable, easy to install and / or able to adapt to different pipe diameters and / or to different, in particular non-round, ceiling or wall openings.

[0010] The problem is solved by the invention defined in the independent claims. Dependent claims describe further developments and preferred embodiments of the invention.

[0011] To solve one, several, or all of the presented aspects of the problem, a formwork sleeve for creating at least partial encasement around an installed pipe is presented, enabling the filling material, in particular concrete or plaster, to be poured around the pipe in the area of ​​a pipe penetration (opening). The formwork sleeve comprises a fluid-fillable inflatable body with a top and a bottom, a pipe opening connecting the top and bottom in which a section of the pipe can be positioned so that the formwork sleeve extends around the pipe section, a separation point extending from an outer surface to the opening, and a fluid inlet for pressurizing the formwork sleeve with a fluid, in particular a gas. The formwork sleeve is designed to seal around the pipe and the pipe penetration when inflated.The upper side of the formwork sleeve forms a receiving surface for the filling material.

[0012] The joint is designed so that the formwork sleeve can be easily slid onto the pipe from the side and, once in place, encircles the pipe like a collar. For example, the joint is an area where two sections of the outer surface of the formwork sleeve lie firmly against each other when the sleeve is inflated, but can be separated when deflated, allowing the sleeve to be placed around the pipe. It is advantageous if the formwork sleeve is quite dimensionally stable when inflated, as it gains its inherent stability through inflation and thus tensioning of the inflatable body, so that in the area of ​​the joint, the outer surfaces of the inflatable body lie against each other when inflated, securely sealing the joint.This has proven to be extremely practical and time-saving in application, also because it always ensures a uniformly straight top surface of the formwork sleeve.

[0013] The separation point is therefore essentially a slit in the filler or inflator. In other words, the filler is not arranged radially around the pipe on all sides, but has a clearance area so that two outer end faces of the filler come into contact at the separation point when filled. The separation point is integrally located in the formwork sleeve or formed integrally with the filler.

[0014] The formwork sleeve can be inflated, for example, using air from a compressor or a hand pump, after it has been positioned around the pipe. For this purpose, it has a continuous opening on one side. The formwork sleeve can be opened at the opening, the two legs of the sleeve guided around the pipe until the pipe is positioned in the opening, and then the legs closed again. If the formwork sleeve is sufficiently rigid when inflated, the opening can be self-locking. An additional fastener, such as a hook-and-loop fastener, can also be attached to the opening, bridging or holding the joint together after installation on the pipe. This fastener thus serves to secure the opening after the formwork sleeve has been placed around the pipe.

[0015] The gas inlet of the formwork sleeve can include a filling connection valve to which a pressure hose can be connected for inflating the inflatable body. In other words, this can be a filling valve, particularly for connection to a compressor. Alternatively or additionally, the gas inlet can include a gas source, in particular a CO2 cartridge, which is designed to empty into the inflatable body upon depletion, thus filling it.

[0016] Furthermore, a non-stick coating or a hydrophobic material may be applied or arranged on the upper side of the formwork sleeve to minimize the adhesion of the filler material to the upper side.

[0017] The formwork sleeve can have one or more indentations on its outer surface to accommodate additional lines, such as fresh water pipes or cables, and seal them together with the pipe. The indentations can be designed to close completely as the filling pressure increases. However, if they enclose, for example, a fresh water pipe, the sleeve will also fit snugly around this pipe. The indentation can optionally be secured with a connecting element.

[0018] The formwork sleeve can have an asymmetrically arranged pipe opening. In other words, the pipe opening is located closer to one side of the formwork sleeve than to the opposite side. This arrangement is advantageous because two adjacent pipes can each be sealed with their own formwork sleeve.

[0019] The inflatable body can also have at least two chambers that can be individually filled or emptied with fluid such as gas. The formwork sleeve can therefore have different chambers, for example, inner and outer air chambers. If a narrow width is required, only the inner air chamber is filled, while the outer air chamber remains unfilled. Multiple filling valves can be provided for this purpose. A lockable cross connector can also be incorporated into the formwork sleeve.

[0020] The formwork sleeve can also include pressure sensors. The detected values ​​can be displayed, for example, as a warning signal or as a range setting with a visual indicator. The pressure sensors can preferably detect the contact pressure exerted by the pipe opening on the pipe section. This allows the correct filling pressure to be determined so that the formwork sleeve encloses the pipe with the correct pressure. Alternatively or cumulatively, the pressure sensors can detect the pressure exerted from the top of the formwork sleeve on an area surrounding the pipe passage. By detecting the contact pressure, it can be verified that the formwork sleeve provides sufficient sealing against the ceiling or wall area at its top.

[0021] A formwork sleeve according to one of the preceding claims, wherein at least the upper surface comprises a self-healing membrane. This can be a self-dividing polymer that repairs minor cracks or damage independently. This increases the service life of the formwork sleeve and / or reduces downtime due to repairs.

[0022] The formwork sleeve can further include an integrated heating system to promote the hardening of the infill material in contact with the formwork sleeve. The heating system can have heating wires embedded in the top of the formwork sleeve, which can heat the infill material lying directly on the formwork sleeve.

[0023] The pipe opening can have an adapter piece on its inner side to adapt to different pipe types or diameters. These adapter pieces can be made of a compressible material, allowing each adapter piece to cover a range of pipe diameters.

[0024] The formwork sleeve can be shaped like a shell when filled. In other words, the outer edges protrude higher than the inner adhesive sleeve or pipe opening, which secures the formwork sleeve to the pipe. This results in greater contact pressure against the ceiling or wall. This can be achieved by making the material of the upper surface of the formwork sleeve shorter than the underside, meaning the upper surface has a smaller surface area than the underside. With correct positioning, the upper surface will still appear nearly flat when installed on a ceiling or wall, but the outer edges of the formwork sleeve will exert greater pressure against the ceiling or wall. This deformation of the formwork sleeve creates a prestressing force.

[0025] Furthermore, a method for enclosing a pipe penetration around an already installed pipe is defined, comprising the following steps. First, a formwork sleeve is placed around the pipe, specifically as described above. This is followed by positioning the formwork sleeve adjacent to the pipe penetration. A gas-fillable inflatable element (filling element) is inflated with gas until the formwork sleeve and pipe penetration opening are tightly pressed against the pipe, as well as against the wall or ceiling surrounding the pipe penetration. Once the formwork sleeve is prepared in this way, the construction site is ready for filling the penetration. Therefore, filling material, especially concrete or plaster, is applied to the top of the pressurized formwork sleeve and around the pipe within the pipe penetration. The filling material then hardens.After the filling material has solidified or hardened, the inflatable element is deflated, thus separating the top of the formwork sleeve from the filling material. This step has proven particularly practical, as a rigid formwork sleeve would adhere permanently to the concrete and be almost impossible to remove. By releasing the gas from the formwork sleeve, however, the top can be easily and quickly peeled off the filling material. The inflatable sleeve can therefore be deflated after use, making the material flexible and allowing it to be easily removed from the concrete, even in tight installation spaces. The formwork sleeve can then be removed from the pipe.

[0026] The formwork sleeve is placed around the pipe and, in the case of a ceiling penetration, pushed up against the ceiling from below. A filling port may be provided to inflate the formwork sleeve using a compressor. The port should be oriented downwards or away from one side of the pipe. The sleeve is inflated, clamping itself very tightly to the pipe. It can be inflated to, for example, 6 bar. Once the formwork sleeve is at the correct height, it seals against the pipe on the inside and presses against the ceiling on the surface, thus sealing the entire ceiling penetration. Concrete can then be poured onto the top surface from above.

[0027] For example, a release agent can be applied to the surface before the concrete is poured to further reduce adhesion to the concrete. The formwork sleeve can have a technical fabric surface, such as a PVC woven fabric. This increases its tear resistance. The surface should be tear-resistant because the concrete can compress as it sets, thus exerting stress on the surface. Since the concrete typically bonds at the top, resistance to cracking is advantageous.

[0028] In the case of a wall penetration or opening, plaster is used instead of liquid concrete. Thanks to the formwork collar, the plaster can simply be "thrown" against the collar from the opposite side. The collar ideally forms a flat surface on its upper side, which, if correctly positioned, requires no further work. The plaster adheres to the collar and grips the wall opening. This allows the area around the pipe to be filled in a single step, without the need for complex formwork or multiple visits from the plasterers, who would otherwise have to apply several coats. Instead, the formwork collar enables this to be done in a single operation in less time.

[0029] The invention is described in more detail below with reference to exemplary embodiments and the figures, wherein identical and similar elements are partially provided with the same reference numerals and the features of the different exemplary embodiments can be combined with one another. Brief description of the characters

[0030] It shows: Fig. 1 Perspective view of a formwork sleeve, Fig. 2 Top view of a formwork sleeve, Fig. 3 Side view of a formwork sleeve, Fig. 4 Perspective view of another embodiment of a formwork sleeve, Fig. 5 Top view of a formwork sleeve, Fig. 6 Schematic representation of a formwork sleeve arranged on a pipe, Fig. 7 Another schematic representation of a formwork sleeve arranged on a pipe, Fig. 8 Another schematic representation of another embodiment of a formwork sleeve arranged on a pipe, Fig. 9 Another schematic representation of an embodiment of a formwork sleeve arranged on a pipe, Fig. 10 Schematic representation of an embodiment of two formwork sleeves, each arranged on a pipe, Fig. 11 Flowchart of a method for using a formwork sleeve. Detailed description of the invention:

[0031] Referring to the Fig. 1Figure 1 shows a perspective view of the underside 12 of a formwork sleeve 10, the underside 12 having a gas connection 20. A pipe passage opening 30 with an inner wall 32 is arranged in the center of the formwork sleeve 10, with a separation point 40 extending from an outer surface 14 to the inner wall 32 of the pipe passage opening 30. The formwork sleeve 10 can be arranged around a pipe, preferably in its uninflated state. If the formwork sleeve 10 is not fully inflated but soft and malleable, the arrangement on the section 52 of the pipe 50 can be carried out more easily. It is also possible to move the formwork sleeve 10 along the pipe extension direction 58 until the formwork sleeve 10 is finally arranged on the desired section 52.

[0032] Fig. 2Figure 1 shows the formwork sleeve in a top view of the underside 12. A closure 42 is arranged on the circumferential outer surface 14, which is designed to be detachable from the outer surface 14. After the formwork sleeve 10 is arranged around the pipe 50, the closure 42 can be used to secure the joints 40. The closure 42 thus prevents the formwork sleeve 10 from bulging in the area of ​​the joints 40 and potentially failing to provide sufficient sealing in this area. In other words, the closure 42 absorbs a clamping force that ensures the joint 40 remains sealed. With reference to Fig. 3 A formwork sleeve is shown in side view, showing an exemplary extent of the closure 42. In a simple example, the closure 42 can be designed as a retaining strap, for example as a hook and loop fastener.

[0033] Fig. 4Figure 1 shows another embodiment of the formwork sleeve with a round shape, which can advantageously adapt to the installation situation. The same reference numerals denote the same elements described above.

[0034] With Fig. 5 In this example, a top view of the upper surface 16 of the round embodiment is shown. A coating 15 is arranged on the upper surface, which reduces the adhesion with the filler material. For example, this could be a hydrophobic material or a coating 15 comprising a water-repellent layer.

[0035] Furthermore, in the with Fig. 5In the example shown, heating wires 35 of a heating device 34 are sewn into the upper surface 16. These heating wires can be switched on after the formwork sleeve 10 has been filled with gas, allowing the filling material applied to the formwork sleeve 10 to dry more quickly by means of the heating wires 35. The heating wires 35 are supplied with power via an inward-facing electrical connection 36. For example, a power storage device (not shown) can also be integrated into the formwork sleeve 10 to provide power to the heating device 34.

[0036] Referring to the Fig. 6The fully inflated formwork sleeve 10 is shown, which is arranged on a pipe 50 and forms a formwork for a schematically depicted opening 62 in a wall or floor slab 60 from one side. If, in this example, the opening is a floor slab 60, the formwork sleeve 10 forms the opening 62 in the floor slab 60 from below. Thanks to the internal pressure, the formwork sleeve 10 encloses a pipe section 52 so tightly that it cannot slip. Nevertheless, when the formwork sleeve 10 is uninflated, it is very easy to position it on the correct pipe section 52. In the correct position, the formwork sleeve 10 also encloses the opening 62, with its upper surface 16 pressing against the floor slab 60 on the outer surface 14.If necessary, the formwork sleeve 10 can be cup-shaped to better press against the floor slab 60, which means that the outer surface 14 is closer to the floor slab 60 than the pipe passage opening 30. For example, this can be achieved by making the top surface 16 shorter or narrower than the bottom surface 12.

[0037] The pipe section 51 is to be surrounded or encased in a filling material within the opening 62. Thanks to the use of the formwork sleeve 10, this filling material can be introduced into the opening 62 as soon as the formwork sleeve is inflated and presses against the floor slab or wall 60.

[0038] With regard to the Fig. 7Another embodiment of the formwork sleeve 10 is shown, which now has a built-in gas source 22, such as a CO2 cartridge. The gas source 22 can independently pressurize the formwork sleeve 10 upon activation. Furthermore, this embodiment includes a cutout 44 through which another pipe or cable 54 can be passed and sealed to the formwork sleeve 10. The pipe 54 is, for example, a fresh water pipe that passes through the formwork sleeve 10 at the through-opening 46. The cutout 44, like the joints 40, can have a closure 42. However, since the cutout 44 is significantly shorter, it can also be designed to seal without a closure 42.The sewage pipe 50 and the fresh water pipe 54 are thus jointly encased in the opening 62 with filling material, with the formwork sleeve 10 completely sealing the opening from below.

[0039] With Fig. 8 Another embodiment of the formwork sleeve 10 is shown, wherein the cut 44 has an angle so that different installation positions of the further line 54 can be accommodated, and the formwork sleeve 10 maintains its tightness and reliable formwork even in different installation positions. A filling connection 20 is arranged on the underside of the formwork sleeve 10, which can, for example, be designed to receive compressed air from a commercially available air compressor in order to pressurize the formwork sleeve 10.

[0040] Further referring to Fig. 9Figure 10 shows a further embodiment of the formwork sleeve 10, which has two separate filling chambers or inflation chambers 18, 19, separated by a partition 17. The separate filling chambers 18, 19 allow a single formwork sleeve 10 to cover a variety of applications. In confined spaces, it may be advantageous to fill only the inner filling chamber 18. However, if a larger opening 62 needs to be covered, the outer filling chamber 19 can also be filled, thus covering different application requirements with just one formwork sleeve 10. For example, the outer filling chamber 19 can also be attached to the partition 17 using fasteners such as a zipper.

[0041] In a simple case with only one filling chamber, the outer wall of the inflation body 18, 19 is also the casing of the formwork sleeve 10, so that the inflation body 18, 19 is not a separate component. Rather, in this case, the interior formed by the formwork sleeve 10 is simultaneously the inflation body 18, 19. For this purpose, the casing of the formwork sleeve 10 can have a gas-impermeable coating on the inside or be made of a gas-impermeable material.

[0042] Finally, referring to the Fig. 10 Figure 1 shows another embodiment in which two pipes 50, 55 are to be filled with filling material in close proximity to each other in a common opening 62. For such installation situations, it can be advantageous if the respective pipe passage opening 30 is arranged asymmetrically on the formwork sleeve 10. As shown in Figure 1 Fig. 10As can be seen, in this case it is provided that the formwork sleeves 10, 11 can be rotated so that the sleeve 10 in the direction of the closely adjacent second pipe 55 only applies a small amount of material to the pipe 50, so that the second formwork sleeve 11 can nestle against the first formwork sleeve 10 at a contact surface 13 and the opening 62 is thereby sealed.

[0043] Now referring to the Fig. 11A flowchart for procedure 100, which uses the formwork sleeve 10, 11, is explained. As a rule, the procedure 100 presented here follows the laying of a pipe 50, meaning that the pipe 50 is already fully installed before this procedure begins. The formwork sleeve 10 can, of course, also be attached to a pipe 50 that is still free at one end. This would be even simpler, as no separation point 40 would then be necessary. However, such an installation situation is not the norm, which is why the complications described above arise. In any case, the first step of the procedure is to place the formwork sleeve 10 around the pipe 50. Typically, for this step 110, the sleeve 10 is emptied or at least partially emptied, so that it is flexible, soft, and easy to handle. In particular, the sleeve 10 is movable along the pipe 50 at the time of step 110.If the sleeve 10 is not already perfectly positioned in step 110, in step 120 the formwork sleeve 10 is positioned adjacent to the opening 62 or the pipe penetration through the masonry or the floor slab. During positioning in step 120, a mark can be made on the pipe 50 using a spirit level or a suitable tool, aligning it with the wall or floor slab 60, for example, the underside of the floor slab 60. The sleeve 10 can then be easily aligned with this mark, for example, directly below the floor slab 60. The position of the sleeve 10 also depends on the shape of the top 16 of the sleeve 10.For example, if the collar 10 is cup-shaped, i.e., the outer edge lifts upwards, it may be useful to position the collar 10 slightly below the floor slab 60, and yet the outer edges will seal tightly around the opening 62 against the floor slab 60.

[0044] The gas-fillable inflatable body 18, 19 is then inflated with a suitable gas, for example, to a predetermined pressure in step 130. In any case, the inflation of the gas-fillable inflatable body 18, 19 continues until the formwork sleeve 10 presses tightly against the pipe 50 in the area of ​​the pipe penetration opening 30. By pressing against the pipe 50, the formwork sleeve 10 becomes self-supporting and is held or supported by the pipe 50 without requiring any additional support. Furthermore, the formwork sleeve 10 also presses against the area surrounding the pipe penetration 62. The opening or pipe penetration 62 is thus sealed or enclosed from one side, for example, the underside in the case of a floor penetration. In the hands of a professional, this process can be completed in just a few minutes - thus saving many hours of working time compared to the current state of the art.

[0045] Once the opening or pipe penetration 62 is formed in this manner in step 130, in step 140, filler material, in particular concrete or plaster, is applied to the top surface 16 of the pressure-filled formwork sleeve 10. In other words, concrete or plaster is placed around the pipe in the pipe penetration or opening 62. The formwork sleeve 10 is sufficiently rigid to support the applied concrete on its top surface. If necessary, it may be advantageous to first apply a lightweight material such as lightweight concrete or a small amount of a fast-setting material, such as rapid-setting concrete, to the formwork sleeve 10 and allow it to set. This allows an additional hard layer to be applied to the top surface 16 of the formwork sleeve 10, which, together with the formwork sleeve 10, supports the further application of filler material.In this case, it can even be advantageous for the first material (expanded concrete or rapid-setting concrete) to form a certain bond with the upper surface 16 of the formwork sleeve 10. This creates a load-bearing bond between the upper surface 16 of the formwork sleeve 10 and the first layer of filler material. Finally, the entire opening or pipe passage 62 is filled with filler material.

[0046] Once the lower part of the filler material has sufficiently solidified or hardened, the formwork sleeve 10 can be vented in step 150, which also makes the upper surface 16 soft and malleable. In its vented state, the formwork sleeve 10 can then be detached from the filler material 64. Since the formwork sleeve 10 no longer seals tightly around the pipe 50, it can now simply be removed from the pipe 50 in step 160. If the formwork sleeve 10 has been used correctly, the process is thus complete. Ideally, it is also unnecessary to further process the filler material 64, as both the underside and the upper surface of the filler material 64 have formed smooth and even surfaces.

[0047] The present description contains a large number of aspects which, individually or together with others, can define essential aspects of the invention(s).

[0048] It is evident to those skilled in the art that the embodiments described above are to be understood as examples and that the invention is not limited to them, but can be varied in many ways without departing from the scope of the claims. Furthermore, it is evident that the features, regardless of whether they are disclosed in the description, the claims, the figures, or elsewhere, also individually define essential components of the invention, even if they are described together with other features. In all figures, the same reference numerals represent the same objects, so that descriptions of objects that may only be mentioned in one figure, or at least not with respect to all figures, can also be applied to those figures and embodiments with respect to which the object is not explicitly described in the description. Reference symbol list

[0049] 10 Formwork collar 11 Another formwork collar 12 Underside 13 Contact surface 14 Outer side 15 Repellent layer 16 Top side 17 Partition wall 18 First filling chamber 19 Second filling chamber 20 Gas valve 22 Gas source 30 Pipe penetration opening 32 Inner side 34 Heating system 35 Heating wires of the heating device 36 Electrical connection 40 Disconnection point 41 Disconnection points in outer filling chamber 42 Closure or retaining strap 44 Cutout 46 Opening for further pipe or cable 50 Pipe 51 Pipe section in floor slab 52 Pipe section in pipe penetration opening of the formwork collar 54 Further pipe or cable 58 Pipe direction 60 Wall or floor slab 62 Penetration 64 Filling material 70 Pressure sensor 72 Pipe contact pressure sensors 74 Surface contact pressure sensor 100 Method for using a formwork sleeve

Claims

1. Formwork sleeve (10) for preparing at least a partial formwork around a laid pipe (50), so that a filling material (64), in particular concrete or plaster, can be filled around the pipe in the area of ​​a pipe passage (62), comprising a fluid-fillable filling body (18, 19), a pipe passage opening (30) in which a section (52) of the pipe can be arranged, so that the formwork sleeve extends around the pipe section, a separation point (40) extending from an outer surface (14) to the pipe passage opening, a fluid inlet (20, 22) for pressurizing the formwork sleeve with a fluid, in particular a gas such as compressed air, wherein the formwork sleeve is prepared in such a way as to seal around the pipe and the pipe passage in the pressurized state and wherein a top surface (16) of the formwork sleeve forms a receiving surface for receiving the filling material.

2. Formwork sleeve (10) according to the preceding claim, wherein the fluid inlet (20, 22) comprises a filling connection valve (20) to which a pressure hose for filling the filling body (18, 19) can be connected, or wherein the fluid inlet comprises a gas source (22), in particular a CO2 cartridge, which is arranged such that it empties into the filling body when emptied and thus fills it.

3. Formwork sleeve (10) according to one of the preceding claims, wherein the upper surface (16) is arranged such that, in the inflated state, it forms a uniform, in particular continuous or flat, receiving surface for receiving the filling material.

4. Formwork sleeve (10) according to one of the preceding claims, further comprising a connecting means (42) for securing the separation point (40) after the formwork sleeve has been folded around the pipe (50).

5. Formwork sleeve (10) according to one of the preceding claims, further comprising a non-stick coating (15) or hydrophobic material on the top surface (16) of the formwork sleeve to reduce the adhesion of the filler mass (64) to the top surface.

6. Formwork sleeve (10) according to one of the preceding claims, characterized by the fact that the formwork sleeve has one or more indentations (44) on its outer side (14) which can accommodate one or more additional lines (54), such as fresh water pipes or cables, and seal them together with the pipe (50).

7. Formwork sleeve (10) according to one of the preceding claims, characterized by an asymmetrically arranged pipe passage opening (30) in the fill body (18, 19), designed in such a way that two closely adjacent pipes (50, 55) can be sealed with their own formwork sleeve (10, 11).

8. Formwork sleeve (10) according to one of the preceding claims, characterized by the fact thatthe packing body (18, 19) has at least a first and a second chamber which can be individually filled or emptied with fluid, in particular gas.

9. Formwork sleeve (10) according to one of the preceding claims, further comprising a pressure sensor system (70, 72, 74), wherein the pressure sensor system in particular detects the contact pressure exerted by the pipe passage opening (30) on the pipe section (52) and / or wherein the pressure sensor system in particular detects the pressure exerted by the top (16) of the formwork sleeve on an area surrounding the pipe passage (62).

10. Formwork sleeve (10) according to one of the preceding claims, wherein at least the upper surface (16) comprises a self-healing membrane.

11. Formwork sleeve (10) according to one of the preceding claims, further comprising an integrated heating system (34) for promoting the hardening of the filling material adhering to the formwork sleeve, wherein the heating system in particular comprises heating wires (35) embedded in the top of the formwork sleeve.

12. Formwork sleeve (10) according to one of the preceding claims, wherein the pipe opening (62) has an adapter piece for adapting to different pipe types or pipe diameters.

13. Method (100) for enclosing a pipe passage (62) around an already laid pipe (50), comprising the following steps: applying (110) a formwork sleeve (10), in particular according to one of the preceding claims, around the pipe; arranging (120) the formwork sleeve adjacent to the pipe passage; filling (130) a fluid-fillable filling body (18, 19) with a fluid, in particular a gas, until the formwork sleeve is tightly pressed against the pipe and / or the area surrounding the pipe passage (62); applying (140) filling material (64), in particular concrete or plaster, to a top surface (16) of the pressurized formwork sleeve and around the pipe in the pipe passage; after the filling material has solidified or hardened, emptying (150) the filling body, in particular by venting, and thus releasing the top surface of the Remove the formwork sleeve from the filler material, (160) remove the formwork sleeve from the pipe.

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