The invention relates to a wall formwork for the construction of walls of concrete and a method of removing concrete from an anchor hole.

A wall formwork comprises a formwork facing supported by supporting elements. The supporting elements can be longitudinal beams and cross beams. The supporting elements can be made of metal. Longitudinal beams and cross beams can form a frame for the wall formwork. Anchor holes pass through supporting elements.

The two sides of a wall that is to be constructed are delimited by wall formworks, namely by formwork facings of the wall formworks. Opposite wall formworks are held by anchor systems. The anchor rods of the anchor systems are then inserted through anchor holes in the wall formwork and attached at their ends to the elements supporting the respective formwork facings by means of locking devices in such a way that at least the tensile force acting on the anchor rods during concreting is absorbed.

In formwork technology, a distinction is made between adjustable and closing formwork. An adjustable formwork is a wall formwork which is installed first. Then the closing formwork is installed opposite the adjustable formwork. Adjustable formwork and closing formwork are connected to each other by one or more anchor systems during assembly. Concrete is poured into the space between the adjustable formwork and the closing formwork. A wall is created by the subsequent hardening of the concrete.

No concrete should enter anchor holes. To avoid this, unused anchor holes are closed with a cap in accordance with publication WO 2014/048937 A1. In addition, an anchor seal is known from WO 2014/048937 A1 , which seals a space between an anchor hole and an inserted anchor rod so that no liquid concrete can flow into the anchor hole.

From the publication DE 10 2009 010 722 A1 a sleeve is known which is inserted into anchor holes. The sleeve has a seal which, when installed, seals a space between anchor rod and anchor hole so that no liquid concrete can flow into the anchor hole. The seal is connected to the sleeve via a predetermined breaking point in order to be able to easily remove a damaged seal from the sleeve if necessary. There is a clearance between the sleeve and the anchor hole, so that the sleeve can be easily pulled out of an anchor hole after the seal has been released, namely towards the side of a wall formwork facing away from the formwork facing, i.e. outwards.

It is known from the publication DE 10 2010 011 173 A1 that an anchor hole is provided with an outer sleeve and an inner sleeve which are interlocked with each other in order to fasten them to an anchor hole in a form-fit manner. There is an elastic seal to seal a gap between an anchor rod and the anchor hole at the formwork facing. Through the seal it is intended to prevent concrete from flowing into an anchor hole.

Despite the measures known from the prior art to prevent concrete from penetrating anchor holes, concrete can still get into anchor holes if seals are damaged or if an unused anchor hole has not been closed as planned.

It is the problem to be solved to be able to remove concrete from an anchor hole of a wall formwork with little effort.

The problem to be solved is solved by a wall formwork with the features of the first claim. An accessory claim relates to a method for a removal of concrete from an anchor hole. Advantageous embodiments result from the subclaims. The invention further relates to a sleeve for wall formwork.

Claim 1 relates to a wall formwork for the construction of walls with a formwork facing and elements which support the formwork facing. The supporting elements preferably consist of metal, in particular of a steel. They are usually beams running longitudinally and transversely behind a formwork facing. Beams on the edge side can be used as frames for the formwork facing. The formwork facing is attached to the beams, for example screwed or riveted to the beams.

Anchor holes pass through supporting elements. In each anchor hole, a sleeve made of plastic is held in a force-fit and/or form-fit manner. An anchor hole therefore has a sleeve even if no anchor rod is inserted through the anchor hole. Each sleeve can therefore be held in the anchor hole by static friction, for example. The sleeve extends from one end of the anchor hole to the other end of the anchor hole. The outer face of the sleeve tightly abuts the inner face of the anchor hole, at least at the side of the formwork facing, so that no concrete can get between the sleeve and the anchor hole from the side of the formwork facing. The sleeve is preferably flush with the opposite side of the anchor hole. This means that the sleeve does not protrude from the anchor hole, nor is it set back from the anchor hole.

If concrete enters the anchor hole unintentionally, hardened concrete can be knocked out of the anchor hole relatively easily due to the sleeve, e.g. with a hammer and chisel. If there was no sleeve, concrete can usually not be knocked out of the anchor hole with a hammer and chisel. If necessary, a damaged sleeve can also be removed relatively easily afterwards, for example by knocking it out. The use of a drill bit is therefore advantageously no longer necessary.

In particular, the wall of the sleeve is completely closed. Thus, there is no opening within the wall through which concrete could pass. This further improves the ability to knock concrete out of the anchor hole relatively easily with a hammer and chisel.

In an advantageous embodiment, the sleeve has a flange on the side of the formwork facing. By the flange it is prevented that the sleeve is pulled out from the side opposite the formwork facing. During concreting, the sleeve cannot be pushed out of the anchor hole with improved reliability.

The flange is located in particular in a recess of the formwork facing. The flange does not rest on the formwork facing. Instead, the flange rests on a supporting element. Then, the formwork facing can adjoin laterally at the flange. It is advantageous if the flange is flush with the formwork facing.

Alternatively, the flange is located in an enlargement of the anchor hole. The flange then rests on the bottom of the enlargement. It is advantageous that the flange is flush with the anchor hole. The surface of the flange and the edge of the anchor hole which are then visible then form a common plane. Then, the formwork facing can adjoin laterally at the edge of the anchor hole. The formwork facing is then advantageously flush with the anchor hole. The surface of the formwork facing and the edge of the anchor hole which are then visible then form a common plane.

The diameter of the recess advantageously corresponds to the diameter of the flange in such a way that an essentially closed surface is provided. Between the flange and the formwork facing there is therefore preferably no gap into which concrete could flow.

In an advantageous embodiment there are one or more anchor holes, which are closed by a cap on the side of the formwork facing. In particular, the cap is held in a force-fit and/or form-fit manner on the sleeve. Particularly, the cap can be removed without tools. With this embodiment, the number of anchor rods used can be adapted to the actual requirements in order to speed up assembly and disassembly.

In one embodiment of the invention, the circumferential surface of the sleeve has grooves on the outer face. The grooves preferably run parallel to the longitudinal axis of the sleeve in order to be able to insert a sleeve into an anchor hole with particularly little effort. The grooves preferably extend to the end of the sleeve which is opposite the formwork facing. The grooves preferably reach to the end of the sleeve which is at the formwork facing without reaching this end. There is then a section that is free of grooves and which has a smooth surface. This makes it possible to provide a tight joint at the formwork facing in which no concrete can flow. However, excessive force is avoided to easily remove and insert a sleeve from the anchor hole for replacement when necessary.

In one embodiment, the sleeve has one or more laterally outwardly projecting projections which are engaged with holes in the inner wall of an anchor hole to fix the sleeve in the anchor hole in a form-fit manner. By knocking it out, it is still possible to remove such a sleeve from an anchor hole if necessary, in order to be able to replace a damaged sleeve with an undamaged one. In particular, the projections run ramp-shaped towards the formwork facing to facilitate insertion of the sleeve into the anchor hole from the side of the formwork facing. Instead of projections, other form-fit elements can also be provided. For example, a flexible lug can be provided as a form-fit element, which protrudes from the outer face of the sleeve at an angle of less than 90°. In particular, the sleeve is manufactured in one piece. The sleeve may have been manufactured in one piece by injection moulding.

The sleeve has in one embodiment a seal on the side on which the formwork facing is located, the seal consisting in particular of an elastomer and thus of an elastic material. In particular, the seal reduces the inner diameter on the side of the formwork facing. An opening leading here into the sleeve is therefore smaller than the other internal diameter of the sleeve. This creates a particularly tight connection between an anchor rod inserted through it and the sleeve, in order to prevent concrete from flowing into the sleeve in an improved manner. The seal is basically made of a plastic which is more elastic compared to the plastic of which the sleeve is made. The plastic of the sleeve is otherwise basically a hard plastic.

In one embodiment of the invention, the sleeve has an internal thread. The internal thread creates a fastening possibility for such anchor holes, through which no anchor rod is pushed. It can then be screwed in from the side opposite the formwork facing, for example, a screw to be able to fasten something.

In the following, the invention is further explained using figures.

The figures show:

Figure 1 : section through wall formworks installed opposite each other;

Figure 2: enlarged section from Figure 1 ;

Figure 3: Sleeve;

Figure 4: Sleeve with latching element;

Figure 5: Sleeve with latching elements and seal;

Figure 6: Sleeve with cap as cover;

Figure 7: Sleeve with internal thread and latched latching elements;

Figure 8: Sleeve with flange in funnel-shaped enlargement of the anchor hole;

Figure 9: Sleeve with flange in step-shaped enlargement of the anchor hole;

Figure 10 Sleeve with resilient locking element. Figure 1 shows a section through wall formworks installed opposite each other for the construction of walls with a formwork facing 1 and elements 2 which support the formwork facing. The elements 2 are beams made of steel.

Anchor holes 3 pass through the supporting elements 2. In each anchor hole 3, a sleeve 4 made of plastic is held in a force-fit manner. Each sleeve 4 is therefore held in the anchor hole 3 by static friction. The sleeve 4 extends from one end of the anchor hole 3 to the other end of the anchor hole 3. On the outer face, each sleeve 4 is flush with the anchor hole 3. The inner wall of each anchor hole 3 is therefore completely covered by the sleeve 4. The outer face of each sleeve 4 tightly borders the inner face of the anchor hole 3 at the side of the formwork facing so that no concrete can flow between the sleeve 4 and the anchor hole 3 from the side of the formwork facing.

Each sleeve 4 has a flange 5 on the side of the formwork facing which rests on the beam 2. Therefore, the sleeves 4 cannot be pulled outwards out of the anchor hole 3. The flange 5 is flush with the formwork facing 1. Thus, the flange 5 neither protrudes from the formwork facing 1 nor is it set back from the formwork facing 1. The flange 5 is located in a recess of the formwork facing 1. The gap between the flange 5 and the formwork facing 1 is minimal, so that no concrete or almost no concrete can flow in. This allows a correspondingly evenly smooth surface of a concrete wall to be produced even in the area of the anchor holes.

Each circumferential surface of the sleeves 4 has grooves 6 on the outer face (see the enlarged illustration in Figure 2, which shows section V of Figure 1 ). The grooves 6 run parallel to the longitudinal axis of each sleeve 4. The grooves 6 extend towards the outside, i.e. to the end opposite the formwork facing. The grooves 6 therefore reach up to the locking devices 7, which connect the anchor rod 8 to the wall formworks.

The anchor rod 8 is inserted through the anchor holes 3 and protrudes on both outer sides. At the both ends of the anchor rod 8 there is a thread 9, respectively, onto which the locking devices 7 are screwed. The section between the two threads 9 has a smooth surface or a sleeve with a smooth surface so that the anchor rod 8 can be pulled out after concreting. The grooves 6 reach close to the end which lies at the formwork facing 1 , without reaching this end. This leaves a tight connection 10 between an outer face of each sleeve 4 and the inner face of the associated anchor hole 3, into which concrete cannot flow.

Figure 3 shows the sleeve 4 in a perspective view. Sleeve 4 is manufactured in one piece. Thus, no parts have been manufactured separately from each other and then joined together to form the sleeve.

Figure 4 shows a sleeve 4 manufactured in one piece, which additionally has one or more latching elements 11. The one or more latching elements 11 protrude outwards and thus form projections. The one or more latching elements 11 can latch in corresponding recesses in the anchor hole. This allows the sleeve 4 to be held in an anchor hole in a form-fit manner. Latching elements 11 can be arranged distributed around the sleeve circumference. Latching elements 11 are preferably arranged above the grooves 6. Since the material of the sleeve, too, is elastic to a certain degree, the latching elements can be made of a solid material. In this case, the latching elements are therefore not resiliently protruding lug.

The grooves 6 shown in Figure 4 run parallel to the longitudinal axis of the sleeve 4 and reach the end of the sleeve 4 that does not have a flange, so that the sleeve 4 can be inserted into an anchor hole with this end.

Figure 5 shows a section through a sleeve 4 which, compared to the sleeve 4 shown in Figure 4, additionally has seal. The seal is mounted on the flange 5 and has an upwardly protruding annular bead 12 and an inwardly directed annular sealing lip 13 projecting laterally from it. The seal is made of an elastic plastic material. The protruding bead 12 can provide a tight connection between a cap and the flange 5 so that an unused anchor hole can be closed particularly reliably by a cap. The inwardly directed sealing lip 13 can provide a particularly tight connection to an anchor rod inserted through it, as the sealing lip 13 reduces the internal diameter of the "sleeve" component.

Figure 5 illustrates that the latching elements 11 run ramp-shaped towards the flange 5 and thus ramp-shaped towards the formwork facing when the sleeve is inserted in an anchor hole. A cap 14, which closes the opening of the sleeve 4 on the side of the flange 5, is shown in figure 6. This can be connected to the sleeve 4 in a force-fit and/or form-fit manner.

Sleeve 4 may have an internal thread 14 as shown in Figure 7. As the sleeve 4 cannot be pulled outwards out of a wall formwork, the internal thread 15 can be used very reliably for fixing other components. The internal thread 15 is preferably limited to one half of the sleeve, so that the internal thread does not excessively hinder concrete from being knocked out.

The internal thread 15 is preferably located in the half of the sleeve facing away from the side of the formwork facing, i.e. on the outside of the wall formwork. Concrete enters this area last, so that it is advantageous to limit the internal thread to the half at the outside.

The internal thread 15 is used in one embodiment to fasten a cap 14. A thread is then also attached to the cap 15, which can be screwed into the internal thread 15. The cap 15 can thus cover an unused anchor hole 3 particularly reliably.

Figure 7 also shows latching elements 11 which are latched in recesses 16 of the supporting element 2.

Concrete can be knocked out of sleeve 4 relatively easily due to the plastic material. As the sleeve 4 is made of plastic, it can be knocked out of an anchor hole 3 even if latching elements 11 are latched in recesses of the anchor hole 3.

Figure 8 shows a configuration with a flange 5 of the sleeve 4, which is located in an enlargement 17 of the anchor hole 3. The enlargement 17 is funnel-shaped. The inner diameter of the anchor hole 3 thus increases in the area of the enlargement 17. The flange 5 rests on the bottom of the enlargement 17 and thus on the funnel-shaped wall of the enlargement 17. The flange 5 is flush with the anchor hole 3. The then visible surface of the flange 5 and the then visible edge of the anchor hole 3, i.e. the surface of the supporting element 2 adjacent to the enlargement 17, form a common plane. The formwork facing 1 is laterally adjacent to the visible edge 18 of the anchor hole 3. The formwork facing 1 is flush with the anchor hole 3. The surface of the formwork facing 1 and the edge 18 of the anchor hole 8 which are then visible then form a common plane. A flat surface is then formed by the flange 5, the visible edge 18 of the anchor hole 3 and the adjacent formwork facing 1. The formwork facing 1 extends into a step-shaped recess 19 of the supporting element 2 and is thus held by the supporting element 2.

The extension 17 can also be step-shaped, for example, as shown in figure 9.

Figure 10 shows a sleeve 4 manufactured in one piece which comprises one or more latching elements 1 1. The one or more latching elements 11 protrude outwards and thus form projections. Above each latching element 11 there is a slot 20. This allows each latching element 1 1 to pivot resiliently relative to the sleeve, which facilitates inserting the sleeve 4 into an anchor hole. The latching elements 11 in this configuration are therefore elastically flexible relative to the rest of the sleeve.