Tower for a wind turbine made of ring-segment-shaped precast concrete elements

Abstract

Tower (1) for a wind turbine with at least one tower section (3) made of concrete, which is composed of several ring-shaped concrete segments (7) arranged one above the other, forming horizontal joints (6), wherein each concrete segment (7) is composed of at least two ring-segment-shaped precast concrete elements (9) arranged side by side, forming vertical joints (8), each having an outer surface (10), an inner surface (16) as well as an upper, a lower and two lateral contact surfaces (11, 12, 13), wherein the concrete segments (7) of the at least one tower section (3) are connected to each other in the vertical direction of the tower (1) by vertical tensioning devices, wherein the vertical joints (8) of each of two superimposed concrete segments (7) are offset from each other in the circumferential direction of the concrete segments (7), wherein a precast concrete element (9) of an upper concrete segment (7) of the two superimposed concrete segments (7) overlaps a vertical joint (8) of a lower concrete segment (7) of the two superimposed concrete segments (7), and wherein the superimposed concrete segments (7) are tensioned together by the vertical prestressing devices, in particular vertical tendons (18), in such a way that a load-bearing, friction-fit connection is created, characterized by that the precast concrete elements (9) are manufactured as precision parts using formwork, which already achieve their ready-to-install final contour through casting, without the need for any further processing step, wherein the precast concrete elements (9) are preferably cast with such high accuracy that the upper contact surface (11) and the lower contact surface (12) are aligned exactly parallel to each other without post-processing, so that no tolerance compensation measures, in particular bonding the contact surfaces with mortar, are required as planned.

Description

[0001] The present invention relates to a tower for a wind turbine with at least one concrete tower section, which is composed of several superimposed, ring-shaped concrete segments with horizontal joints. Each concrete segment is composed of at least two adjacent, ring-shaped precast concrete elements with vertical joints. The ring-shaped precast concrete elements each have an outer surface, an inner surface, and an upper, a lower, and two lateral contact surfaces. The concrete segments of the at least one tower section are connected to each other in the vertical direction of the tower by vertical tensioning devices.

[0002] Wind turbine towers are known in a wide variety of designs. Besides towers constructed using slipforming in cast-in-place concrete, steel towers and prestressed towers made of precast concrete elements are also known. During operation, the towers are subjected to considerable loads, including wind forces and excitations from the rotating rotor. Therefore, the tower design must exhibit sufficient stiffness even under extreme load conditions.

[0003] EP 1 474 579 B1 shows a tower composed of ring-shaped tower sections, each consisting of several prefabricated concrete elements. These ring-shaped tower sections are vertically braced together by tendons. To assemble the tower, the individual prefabricated concrete elements are joined on-site to form a ring-shaped section, with the vertical joints between two adjacent sections being filled with mortar. Similarly, the horizontal joints between two such sections are also filled with mortar. This ensures the tower's rigidity in both the horizontal and vertical directions. However, on-site assembly of the tower is comparatively complex. Furthermore, the individual prefabricated concrete elements are relatively large, which complicates both their transport to the construction site and their handling on-site.

[0004] EP 2 631 393 A1 also depicts a wind turbine tower composed of large, prefabricated, ring-shaped concrete segments that are vertically braced together by tensioning devices. According to one of the embodiments described therein, the individual ring-shaped concrete segments can also be connected horizontally without mortar, or the vertical joints can be dry-jointed. To achieve the necessary operational stiffness of the tower, the ring-shaped concrete segments are braced horizontally by screws or bolts. The components embedded in the prefabricated concrete elements must be provided with corresponding holes for the bolts or screws and bolted together on site.

[0005] The object of the present invention is to propose a tower made of precast concrete elements which has sufficient stiffness and allows for easy assembly of the tower on the construction site.

[0006] The problem is solved using the features of claim 1.

[0007] A tower for a wind turbine comprises at least one concrete tower section, which is composed of several superimposed, ring-shaped concrete segments connected by horizontal joints. Each concrete segment is composed of at least two adjacent, ring-shaped precast concrete elements connected by vertical joints. The precast concrete elements each have an outer surface, an inner surface, a top surface, a bottom surface, and two lateral contact surfaces. The concrete segments of the at least one tower section are connected to each other in the vertical direction of the tower, in particular only, by vertical tensioning devices.

[0008] It is now planned that the vertical joints of each pair of superimposed concrete segments are offset from one another in the circumferential direction of the concrete segments, with a precast concrete element of an upper concrete segment overlapping a vertical joint of a lower concrete segment. The superimposed concrete segments are prestressed together by vertical tendons, in particular vertical prestressing elements, such that a load-bearing, friction-fit connection is created in the horizontal direction of the tower by the precast concrete element overlapping the vertical joint. This friction-fit connection bridges the vertical joint of the lower concrete segment without the use of mortar or screws, thus achieving good stiffness in the horizontal direction and improved load-bearing capacity under bending stress.The prestressing forces of the vertical tensioning devices must be high enough to ensure that the frictional forces generated in the horizontal joints securely fix the individual precast concrete elements of a segment, even under extreme load conditions, and prevent the vertical joints from opening. Since the step of grouting the vertical joints can be omitted on the construction site, and there is no need to wait for the mortar between the joints to set, the tower can be erected very quickly and cost-effectively.

[0009] It is advantageous if the precast concrete elements of each concrete segment are connected to each other solely by friction, via the precast concrete element spanning the vertical joint, thus transferring the load. This eliminates the need for any further steps to connect the precast concrete elements or segments beyond the application of vertical prestressing, contributing to simple and cost-effective assembly. Furthermore, the tower is designed for easy dismantling. However, it is also conceivable to incorporate one or more bolted connections in addition to the friction connection, preferably designed solely as tension fasteners. These bolted connections are installed without prestressing and serve only to absorb any tensile loads that may occur.

[0010] In a first design, at least the lateral contact surfaces of the precast concrete elements are flat, meaning they form a smooth, even surface without protrusions, depressions, interlocking joints, or the like. To create the vertical joints, the contact surfaces then butt against each other. This simplifies the production of the precast concrete elements and their formwork. For this reason, the upper and lower contact surfaces can also be flat. However, it is also possible to design the upper and / or lower contact surfaces with a positioning aid, a shear interlock, or similar device.

[0011] According to another embodiment, the lateral contact surfaces of the precast concrete elements can also each have at least one, preferably two, raised contact areas. These contact areas facilitate the alignment of adjacent precast concrete elements within a concrete segment, thereby ensuring the tower's horizontal stiffness and / or improved load-bearing capacity under bending stress. At the same time, the contact areas also simplify the positioning of the individual precast concrete elements during assembly.

[0012] Furthermore, it is advantageous if the precast concrete elements have additional reinforcement or an increased reinforcement content at least at their upper end and preferably also at their lower end, particularly in a central area, relative to the width of the precast concrete elements. The additional reinforcement or the increased reinforcement content absorbs stress peaks that occur under load in the upper area of ​​the precast concrete elements, specifically below the vertical joints of the concrete segment above.

[0013] In a further development of the invention, at least the upper and lower contact surfaces of the precast concrete elements are ground smooth. This allows for the production of very precisely shaped precast concrete elements that require no further alignment or leveling work on the construction site. It can also be advantageous to grind the lateral contact surfaces to facilitate precise alignment of the precast concrete elements during assembly and to minimize vertical joints. If raised contact areas are provided on the lateral contact surfaces, it is advisable to grind these smooth to achieve precise alignment of the precast concrete elements relative to each other. In this case, the lateral contact surfaces themselves do not need to be ground smooth.

[0014] To facilitate the handling of the precast concrete elements or segments and the assembly of the tower on the construction site, it is advantageous if the precast concrete elements of each segment are connected to each other by horizontal prestressing devices. These horizontal prestressing devices can be designed as ring tendons or as bolted connections. However, it is also advantageous if the precast concrete elements of each segment are connected to each other without prestressing by tension connectors, particularly bolted connections. The bolted connections are preferably designed to serve as assembly aids during tower construction and therefore do not constitute a load-bearing connection under normal operating conditions—except under extreme loads. The bolted connections can thus be dimensioned to be comparatively small and cost-effective. Likewise, the bolted connections can be designed to merely accommodate, if necessary,serve to withstand the tensile loads that occur.

[0015] A particularly advantageous embodiment of the tower provides that the concrete segments are composed of at least three, preferably four, ring-shaped precast concrete elements designed as identical parts. The production of the tower and its precast concrete elements is facilitated by the fact that the identical precast concrete elements of at least one segment can be produced using the same formwork.

[0016] It is advantageous if at least the lateral contact surfaces, and possibly also the lateral contact areas of the lateral contact surfaces, and preferably all contact surfaces of the precast concrete elements are formwork-smooth, i.e., unworked, and preferably untreated. This eliminates the need for reworking the precast concrete elements at the precast plant or on-site, further simplifying the tower's construction. In particular, neither material removal nor build-up is required to achieve a smooth surface and compensate for tolerances in the precast concrete elements. For this purpose, the precast concrete elements are manufactured as precision parts in which the upper and lower contact surfaces are exactly parallel to each other. Likewise, the lateral contact surfaces, or at least the contact areas, if present, are precisely positioned relative to the upper and lower contact surfaces.The terms "exactly parallel" and "exactly positioned" refer to a design with such low tolerances regarding the flatness and position of the contact surfaces that no tolerance compensation measures, such as bonding the contact surfaces with mortar or the like, are required. Alternatively or additionally, the contact surfaces and / or the lateral contact areas can also be ground flat.

[0017] It is particularly advantageous if the height of the ring-shaped precast concrete elements is less than their width, preferably with the height being less than one-third, and preferably less than one-quarter, of their width. Since the diameter of wind turbines often reaches up to 10 m, at least at the base, transporting even half-shell precast concrete elements from the factory to the construction site is a complex and costly process. If the precast concrete elements are less tall than wide, preferably less than 3 m high, then, due to the division of the concrete segments into three or more precast elements, they are a size that easily allows for road transport on a width of less than 3 m.Furthermore, the relatively small size of the precast concrete elements allows them to be manufactured on-site at the construction site, eliminating the need for complex transport at the assembly location. This is particularly advantageous when the height of the ring-shaped precast concrete elements is less than 2.5 m.

[0018] It is also advantageous if the vertical tendons are unbonded and located outside the concrete cross-section of the precast concrete elements. Due to the unbonded design of the tendons, the tower can be erected very quickly. Furthermore, this significantly simplifies both the retensioning and replacement of the vertical tendons for maintenance purposes, as well as the dismantling of the tower.

[0019] For a tower prestressed between a top support and a bottom support by means of vertical tendons routed outside the concrete cross-section, it is also advantageous if the tower section has at least one integrally formed projection on its inner wall between the top support and the bottom support, against which at least one of the vertical tendons rests. This allows the at least one tendon to be easily fixed to the inner wall by friction against the projection, thus preventing undesired lateral movement of the tendons.

[0020] It is advantageous if the projection has a rectangular cross-section. This simplifies the production of the tower or tower section, as a projection with a rectangular cross-section can be easily integrated into the formwork, and the tower section can be easily demolded. Furthermore, any harmful effects of the projection on the tendons in the installation area can be minimized. However, it is also conceivable to round off the corners or edges of the rectangular cross-section facing the interior of the tower. Other cross-sectional shapes, such as trapezoidal, semicircular, triangular, etc., are also possible, with rounded corners being advantageous in these cases as well.

[0021] Following a particularly advantageous further development, the projection extends around the entire inner circumference of the tower section. This allows vertical tendons to be positioned at any desired point along the inner circumference of the tower section. Especially when the tower section is precast, such a precast element can be used for different towers with varying numbers of tendons.

[0022] However, it is also possible that only individual, bracket-like projections are arranged at the same height around the inner circumference of the tower section. This can be particularly advantageous for tower sections that are prestressed with only a few tendons distributed around the circumference. Similarly, in a precast tower section, it is conceivable that each precast element is provided with such a single, bracket-like projection. In this case, it is again advantageous if the projections have a concave recess facing the interior of the tower. This ensures that the tendons are particularly well fixed in their transverse direction and simultaneously protected from damaging influences.

[0023] In a further advantageous embodiment, it is provided that at least one tendon rests against at least one projection at a deflection angle. This creates a particularly high frictional force between the tendon and the projection, thus holding the tendon in a particularly favorable manner. Furthermore, such a design ensures that the tendons remain in contact with the projection even when the tower section is subjected to bending stress, e.g., from wind forces.

[0024] According to another refinement, it is advantageous if the tower section has several projections molded onto its inner wall at different heights. This allows the vertical tendons to be fixed to the inner wall of the tower section two or more times along their length, which is particularly beneficial for very tall tower sections exceeding 80 m in height.

[0025] It is particularly advantageous if the tower section has at least one ring-shaped concrete segment to which at least one projection is molded. The tower section is composed of several superimposed, ring-shaped concrete segments, with horizontal joints, and can therefore be constructed using precast elements. The at least one concrete segment with the projection can also be prefabricated.

[0026] Furthermore, it is advantageous if the at least one concrete segment with the projection is composed of at least two adjacent, ring-shaped precast concrete elements. The projection is formed on at least one of the precast concrete elements. This allows tower sections with large diameters, e.g., 4 m and above, to be manufactured using precast construction methods and transported by road. It is particularly advantageous if each of the ring-shaped precast concrete elements of a concrete segment has a projection, so that the tower section as a whole has a circumferential projection.

[0027] Further advantages of the invention are described with reference to the exemplary embodiments shown below. These show: Fig. 1. A tower of a wind turbine with a tower section made of concrete in an overview view, Fig. 2 a schematic representation of a tower section with horizontal and vertical joints, Fig. 3 a ring-segment-shaped precast concrete element in a view from the inside, Fig. 4 a tower prestressed with vertical tendons made of several ring-shaped concrete segments arranged one above the other in a broken, schematic sectional view, Fig. 5 a tower section with a concrete segment composed of four ring-segment-shaped precast concrete elements, in a top view, Fig. 6 another embodiment of a ring-segment-shaped precast concrete element in a front view from the inside, as well as Fig. 7 the ring-segment-shaped precast concrete element of the Fig. 6 in a top view Fig. 8 a tower prestressed with vertical tendons made of several ring-shaped concrete segments arranged one above the other according to a second embodiment in a sectional view, Fig. 9 a ring-shaped concrete segment with a projection in a schematic sectional view, Fig. 10 a ring-segment-shaped precast concrete element with a projection in a top view, Fig. 11 another embodiment of a ring-segment-shaped precast concrete element with a projection in a top view, Fig. 12 another embodiment of a ring-segment-shaped precast concrete element with several projections in a top view as well as Fig. 13 Another embodiment of a ring-segment-shaped precast concrete element with several projections in a top view.

[0028] Fig. Figure 1 shows a tower 1 for a wind turbine with at least one tower section 3 made of concrete. The tower 1 is erected in the usual manner on a foundation 2 and is designed as a hybrid tower, meaning that a further tower section 4 made of steel is arranged on the tower section 3 made of concrete, with the two sections 3 and 4 being connected to each other by means of a transition piece 5. However, contrary to the illustration shown, it is also possible for the tower to comprise only one or more tower sections 3 made of concrete, which can also be designed in different ways. In this case, the tower section 3 made of concrete is conical; however, it is also possible for one or more tower sections 3 made of concrete to be cylindrical, as shown in Fig. 4 shown, or to combine a conical tower section 3 made of concrete with a cylindrical tower section 3 made of concrete.

[0029] The concrete tower section 3 shown here consists of several ring-shaped concrete segments 7 arranged one above the other, each with horizontal joints 6 forming a vertical joint. Each of the concrete segments 7 of tower section 3 in turn consists of at least 3 ring-shaped precast concrete elements 9, which are arranged side by side in the circumferential direction of the individual concrete segments 7 with vertical joints 8 forming a vertical joint.

[0030] The concrete segments 7 of the at least one tower section 3 made of concrete are connected to each other by vertical prestressing devices, in particular vertical tendons 18, as can be seen in particular from the Fig. 4. At the top of tower 1, a nacelle and a rotor of the wind turbine can be arranged in the usual manner (not shown here). In addition to the tower section 3 shown, in which the individual concrete segments 7 are composed of several precast concrete elements 9, further tower sections 3 may be present in which the concrete segments 7 are designed as complete rings. This is particularly advantageous for conical towers 1, in which the upper concrete segments 7 have a smaller diameter.

[0031] Fig. Figure 2 shows a tower section 3 with horizontal joints 6 and vertical joints 8 in a schematic, abbreviated detail view. It is evident that each concrete segment 7 of the tower section 3 consists of at least two precast concrete elements 9, which are joined together by forming a vertical joint 8. Furthermore, it is evident that each precast concrete element 9 has an upper contact surface 11, a lower contact surface 12, and two lateral contact surfaces 13. The lateral contact surfaces 13 are provided with raised contact areas 14, which abut each other in the horizontal direction of the tower 1 or the concrete segment 7. Fig. Figure 3 shows a single, such ring-segment-shaped precast concrete element 9 in a view from the inside 16.

[0032] For reasons of better visibility, in Fig. 2. The contact areas 14 are shown slightly spaced apart and also protruding particularly strongly. In reality, however, in the fully assembled tower 1, the contact areas 14 are mounted flush and protrude only slightly from the lateral contact surfaces 13. Furthermore, the horizontal joints 6 are visible, which are shown completely closed, corresponding to the state after the application of the vertical prestressing.

[0033] As now shown in the schematic longitudinal section of the Fig. The tower section 3, made of concrete, is vertically prestressed by vertical tendons 18, which connect the individual, superimposed concrete segments 7. The vertical tendons 18 are unbonded and located outside the concrete cross-section of the precast concrete elements 9 within the interior 24 of the tower, thus facilitating easy installation. The concrete segments 7 are connected to each other in the vertical direction of the tower 1 only by the vertical tendons 18. The vertical tendons 18 are fixed to a base support, preferably the foundation 2, of the tower 1 and extend at least to the end of the respective tower section 3 made of concrete, where they are preferably connected to a head support, for example, at the transition piece 5 (see figure 4). Fig. 8) are specified. In this case, the vertical tendons 18 are guided through sheathing tubes 17 in the foundation 2.

[0034] In order to make the horizontal joints 6 as narrow as possible or to close them completely, the upper and lower contact surfaces 11, 12 of the precast concrete elements can be ground smooth. The contact surfaces 11, 12 therefore exhibit such low tolerances with regard to both their flatness and their parallelism to each other that, at least after the application of prestressing by the vertical tendons 18, the horizontal joints 6 are almost completely closed. The lateral contact surfaces 13 and their contact areas 14 (see figure) are also closed. Fig. 2 and Fig. 3) can therefore be ground down to make the vertical joints as narrow as possible. Grinding the contact surfaces also facilitates the assembly of the tower section, as the high accuracy regarding the position of contact surfaces 11, 12, 13 eliminates the need for any further alignment work. Alternatively, instead of grinding the contact surfaces 11, 12, 13, it is also possible to manufacture the precast concrete elements as precision parts, as shown by the Fig. 5 - 7 will be explained.

[0035] As can now be seen again from the Fig. As shown in Figure 2, the precast concrete elements 9 of each concrete segment 7 are connected horizontally by a friction-fit, load-bearing connection through the prestressing force of the vertical tendons 18 and the precast concrete elements 9 of the above concrete segment 7 that overlap the vertical joints 8. For the assembly of the tower section 3, the precast concrete elements 9 are therefore simply placed loosely on top of those of the below concrete segment 7 and positioned against their lateral contact surfaces 13 so that the vertical joints 8 are largely closed. The precast concrete elements 9 of the above concrete segment 7 are then positioned so that the vertical joints 8 are offset relative to the below concrete segment 7 and the precast concrete elements 9 of the uppermost concrete segment 7 overlap the vertical joints 8 of the belowmost concrete segment 7.If the concrete segments 7 are composed of two precast concrete elements 9, the precast concrete elements 9 of the superimposed concrete segments 7 are preferably offset from each other by 90°. However, other offset angles, for example only 45°, are also possible. Subsequently, the vertical tendons 18 are inserted and prestressed. The vertical tendons 18 are prestressed with such a high prestressing force that the resulting frictional force in the horizontal joints 6 prevents the precast concrete elements 9 from moving apart in the horizontal direction and thus prevents the vertical joints 8 from opening.

[0036] The tower 1 achieves good horizontal stiffness and improved load-bearing capacity under bending stress through the abutting of the lateral contact surfaces 13 or their contact areas 14. If the contact surfaces 13 are provided with the raised contact areas 14, the positioning of the individual precast concrete elements 9 during assembly is also facilitated. Preferably, the precast concrete elements 9 have at least one contact area 14 on each lateral contact surface 13, by means of which they contact a lateral contact area 14 of an adjacent precast concrete element 9 in the assembled state. If two contact areas 14 are provided on a lateral contact surface 13 of a precast concrete element 9, it is also sufficient if only one of the contact areas 14 contacts a contact area 14 of an adjacent precast concrete element 9 in the vertical joint.

[0037] However, the contact surfaces 13 can also be designed as smooth, flat surfaces without contact areas 14, as in Fig. Figure 5 illustrates this. Since the cohesion of the individual precast concrete elements 9 of a concrete segment 7 is primarily or even exclusively due to the frictional forces in the horizontal joints 6, the contact areas 14 are not strictly necessary. For the same reason, it is also harmless to the stiffness of the tower 1 if the vertical joints 8 open slightly under load or if, due to assembly tolerances, a vertical joint 8 remains completely open. In any case, due to the load-bearing connection provided by the prestressing force of the vertical tendons 18, neither grouting nor bolting of the vertical joints 8 is required.

[0038] However, due to the lack of connection between the individual precast concrete elements 9 of a concrete segment 7, significant stress peaks can occur under load in the area of ​​the precast concrete elements 9 of the underlying concrete segment 7 located below a vertical joint 8. According to the illustration of the Fig. 2. The precast concrete elements 9 are therefore provided with additional reinforcement 15 or increased reinforcement content at their upper end in the area below the vertical joint 8, which is usually located in the middle of the precast concrete elements 9 depending on the offset angle.

[0039] In order to manufacture and assemble tower section 3 of a wind turbine in a particularly simple manner on the construction site, the following is required according to the design according to Fig. Section 5 provides that the ring-segment-shaped precast concrete elements 9 are designed as exact identical parts. This allows for simple production of the precast concrete elements 9 with as few formwork elements as possible. It is advantageous if the individual concrete segments 7 are composed of three or more precast concrete elements 9 instead of two. This makes the individual precast concrete elements 9 smaller and therefore easier to transport to the construction site or to produce on-site using portable formwork.

[0040] To facilitate the handling of the precast concrete elements 9 on the construction site and their positioning on the respective underlying concrete segment 7, the individual precast concrete elements 9 are joined to form a concrete segment 7 by means of horizontal screw connections 19, as shown in the present illustration. For this purpose, two screws 20 are offset vertically at each vertical joint 8 and inserted at an angle into the joint from the inside. The screw connections are easily accessible from the inside 16 via recesses 22, so that the screw connections 19 can be easily installed and, if necessary, easily removed again. Each screw connection 19 includes a dowel 21, which is cast into a lateral contact surface 13 of a precast concrete element 9, and a screw 20, which is inserted into the dowel 21 through the recess 22 of an adjacent precast concrete element 9.

[0041] The bolts 19 are intended as assembly aids and do not serve for force transmission during normal operation. They only serve for force transmission in extreme cases, such as high wind loads. The bolts 19 make it possible to fix several precast concrete elements 9 of a concrete segment 7 together and handle them as a single component. The concrete segment 7 can thus be quickly and easily assembled at the assembly site using the bolts 19 and placed onto the existing tower section 3. The bolts 19 are designed to support the self-weight of the resulting component. The precast concrete elements 9 are therefore connected to each other even before the vertical tendons 18 are tensioned and are thus secured during the assembly of the tower section 3.The screw connections 19 can be left in the precast concrete element after completion of the tower in order to save the step of removal or to ensure the inherent stability of the tower in the event of maintenance, for example when replacing vertical tendons 18, or during dismantling.

[0042] Fig. Figure 6 shows a precast concrete element 9 suitable for such a tower section 3 in a front view from the inside 16 and Fig. 7 in a top view. The precast concrete element 9 has an outer surface 10, an inner surface 16, an upper contact surface 11, a lower contact surface 12, and two lateral contact surfaces 13. Just like the precast concrete element of the Fig. These precast concrete elements 9 can also have contact areas 14. However, the contact surfaces 13 can also be designed as completely flat surfaces. The height H of the ring-segment-shaped precast concrete elements 9 is significantly less than their width B. Preferably, the height H of the precast concrete elements is less than 3 m. The precast concrete elements 9 can therefore be transported in a horizontal position without exceeding the maximum permissible road transport width. It is therefore particularly advantageous if the precast concrete elements 9 have a height of less than 2.50 m, as they can then be transported with conventional transport vehicles. The height of the precast concrete elements 9 is oriented in the transverse direction of the transport vehicle. It is particularly advantageous that, due to their shell-like design, the precast concrete elements 9 are stackable and thus several precast concrete elements 9 can be transported on top of each other.

[0043] The precast concrete elements 9 are manufactured as precision parts using formwork (not shown). This means that the precast concrete elements 9 achieve their ready-to-install final contour directly from the casting process, without requiring any further processing. The precast concrete elements 9 are cast with such high precision that the upper contact surface 11 and the lower contact surface 12 are perfectly parallel to each other without any post-processing. Likewise, the two lateral contact surfaces 13 are precisely perpendicular to the upper and lower contact surfaces 11 and 12, and are aligned at a precise angle to each other. The angle between the two lateral contact surfaces 13 of each precast concrete element 9 is 120° for three precast concrete elements 9 per concrete segment 7, and 90° for four precast concrete elements 9 per concrete segment 7.

[0044] The formwork (not shown) for manufacturing the precast concrete elements comprises two end formwork panels and two side formwork panels, each of which can be adjusted independently of the main formwork panel. Subsequent work to ensure the parallel alignment of any two opposing contact surfaces 11, 12 is therefore unnecessary. Likewise, the orientation of the lateral contact surfaces 13 to the upper and lower contact surfaces 11, 12 is so precisely designed that no leveling compound needs to be applied to the vertical joints when assembling several precast concrete elements 9 to form a ring-shaped concrete segment 7.

[0045] Due to the small dimensions of the precast concrete elements 9 and consequently also of the associated formwork, the precast concrete elements 9 can be manufactured directly at the assembly site or at least very close to it. This eliminates the need for complex transport operations, which often require the construction of new access roads and the clearing of paths. Once the tower 1, or the planned towers 1, are fully erected at the assembly site, the formwork can simply be transported to the next assembly site and used there again for the on-site production of precast concrete elements 9. Thus, despite on-site production, the precast concrete elements 9, or the towers 1, can be manufactured economically.

[0046] Fig. Figure 8 shows another version of a tower 1 in a schematic cross-sectional view. Just like the one in Fig. The tower section 3 shown in Figure 4 is constructed from several ring-shaped concrete segments 7 arranged one above the other. These stacked concrete segments 7 are connected by vertical tendons 18, which extend between a head bearing (here again a transition piece 5) and a foot bearing (here again the foundation 2). The vertical tendons 18 are fastened at least at one of their two ends, but preferably at both ends, by means of a tension anchor and are thus retensionable. The vertical tendons 18 also run outside the concrete cross-section of the concrete segments 7 in the interior space 24, which is enclosed by the inner wall 23 of tower section 3. The inner wall 23 is composed of the individual inner surfaces 16 of the individual concrete segments 7 or of the individual precast concrete elements 9 of the concrete segments 7 (see Figure 4). Fig. 10-12) together. The individual concrete segments 7 can be formed in one piece in a ring shape or, as previously mentioned, based on the Fig. 2-7 described, composed of several ring-segment-shaped precast concrete elements 9.

[0047] Only tower section 3 of tower 1 is shown here. Of course, another tower section 3, 4 made of concrete or steel can also be arranged on this tower section 3, which then, together with tower section 3 shown here, forms tower 1 for the wind turbine. The vertical joints 6 between the individual concrete segments 7 are also visible here. For the sake of clarity, only the outer surface 10 and the inner surface 16 of the individual concrete segments 7 are labeled in this illustration. Naturally, these also each have an upper contact surface 11, a lower contact surface 12, and, if the concrete segments 7 are made of precast concrete elements 9, lateral contact surfaces 13, as described in the previous figures. The same applies to the following Fig. 9-12, on which, for the sake of clarity, only the described components or features were labelled.

[0048] How now the Fig. According to the present illustration, one of the concrete segments 7, which can be removed from the formwork, has a projection 25 on its inner surface 16, against which the vertical tendons 18 rest. The vertical tendons 18 can thus be fixed to the inner wall 23 or to the projection 25 by means of frictional forces, thereby reducing the free oscillation length of the vertical tendons 18 and preventing undesired lateral movements. It is therefore possible to construct even very tall towers 1 without additional, active intermediate fastening of the tendons 18. The concrete segment 7 or precast concrete element 9 with the projection 25 can be manufactured in a particularly simple manner, as the projection 25 can be easily integrated into the formwork. Furthermore, assembly on the construction site is also simplified, since no additional assembly steps are required for this intermediate fastening of the vertical tendons 18.Rather, it is sufficient to fix the vertical tendons 18, for example, at their head bearing, unwind them downwards, and anchor them at their foot bearing. The vertical tendons 18 are automatically guided over the projection 25 and, after tensioning, during which a clamping force is applied to the vertical tendons 18, are fixed to it by friction. A particular advantage is that such a fixation of the vertical tendons 18 to a projection 25 is applicable to various tower section 3 or tower 1 designs. Thus, the integrated projection 25 can be used not only in conjunction with single-piece ring-shaped concrete segments 7, but also with concrete segments 7 composed of several precast concrete elements 9. Furthermore, it is also possible to provide such a projection 25 on a cast-in-place concrete tower.

[0049] Only two vertical tendons 18 are shown here as examples. It is understood that in a real tower section 3, at least three, but usually a large number of vertical tendons 18 are arranged distributed around the inner circumference of the tower section 3. The vertical tendons 18 can be distributed equidistantly around the inner circumference, or individual groups of vertical tendons 18 can be formed, also distributed equidistantly around the inner circumference, with gaps between such groups. However, configurations are also possible in which one vertical tendon 18 extends alongside the next, so that the entire inner circumference of the tower section 3 is covered with vertical tendons 18.

[0050] The projection 25, as shown in the present illustration, extends around the entire inner circumference of tower section 3 or concrete segment 7. It can therefore be used in any tower 1 with any number and arrangement of vertical tendons 18. Furthermore, a tower section 3 is shown here in which only one projection 25 is provided on the inner wall 23. Of course, it is also possible to arrange another projection 25 at a different height relative to the first projection 25 on the inner wall 23 in order to achieve better fixation of the vertical tendons 18 in very tall towers 1. It should also be understood that the present illustration with only five concrete segments 7 is merely an example and that actual tower sections 3 are constructed from significantly more concrete segments 7 or precast concrete elements 9.

[0051] Fig. Figure 9 shows a cross-section of a single-piece, ring-shaped concrete segment 7, which also has a projection 25 on its inner side 16. In contrast to the illustration of the Fig. In this arrangement, the vertical tendons 18 are guided over at least one projection 25 at a deflection angle α. By bearing at a deflection angle α, particularly high contact forces can be generated on the tendons 18, resulting in exceptionally strong fixation due to high frictional forces. Naturally, such a guidance of the vertical tendons 18 at a deflection angle α is also possible in combination with segment-shaped precast concrete elements 9 or a cast-in-place concrete tower.

[0052] Fig. Figure 10 shows a ring-segment-shaped precast concrete element 9, which can be assembled together with other ring-segment-shaped precast concrete elements 9 to form a ring-shaped concrete segment 7. The ring-segment-shaped precast concrete element 9, like the one in Fig. 7 shown above an outer surface 10, an inner surface 16, two lateral contact surfaces 13 and an upper contact surface 11. A lower contact surface 12 (see Fig. 2-4) is not visible in the present illustration. The ring-segment-shaped precast concrete element 9, in turn, has a projection 25 on its inner side 16, which is preferably similar to the one in the Fig. 8 and Fig. The projection 25 shown in Figure 9 is designed in a bracket-like or flange-like manner and preferably has a rectangular cross-section. Preferably, the edges of the rectangular cross-section facing the interior 24 are rounded to prevent damaging effects of the projection 25 on the vertical tendons 18.

[0053] Preferably, several such ring-segment-shaped precast concrete elements 9, four such precast concrete elements 9 as shown in the present illustration, are assembled to form a concrete segment 7, resulting in a circumferential, flange-like projection 25. However, it is also conceivable, particularly with more than four ring-segment-shaped precast concrete elements 9 per concrete segment 7, that only some of the ring-segment-shaped precast concrete elements 9 have such a projection. During the assembly of the tower section 3, these precast concrete elements 9 are then arranged such that the projections 25 are located where vertical tendons 18 are later to be inserted.

[0054] Fig. Figure 11 shows another embodiment of a precast concrete element 9, in which a bracket-like projection 25 does not extend over the entire inner surface 16. Such an embodiment can be advantageous, for example, for demolding and contributes to the fact that the lateral contact surfaces 13 can be formed flat or machined, for example, by grinding, in a particularly simple manner. Here, too, it is conceivable to group several vertical tendons 18 together, with the group of tendons 18 then extending in the area of ​​the projection 25, while no vertical tendons 18 are arranged in the area of ​​the inner surface 16 outside the projections 25.

[0055] Fig. Figure 12 shows another embodiment of a ring-segment-shaped precast concrete element 9, in which several projections 25 are arranged at the same height, but distributed over the inner circumference of the precast concrete element 9 on the inner surface 16. The projections 25 are again provided in the areas of the tower section 3 where the subsequent arrangement of vertical tendons 18 is planned. Of course, it would also be conceivable to provide a ring-shaped concrete segment 7 with such multiple projections 25 distributed over its inner circumference.

[0056] Fig. Figure 13 shows another embodiment of a ring-segment-shaped precast concrete element 9 with several projections 25 distributed around the inner circumference of the precast concrete element 9 and arranged on the inner side 16. However, the projections 25 are not flat on their side facing the interior 24 of the tower, unlike those of the Fig.12, but instead feature a concave recess facing the interior 24. The tendons 18 rest at the lowest point of the concave recess and are thus particularly well fixed in their transverse direction, or are automatically returned to their original position after any deflection. This design is particularly advantageous for wire tendons.

[0057] In summary, the construction of the present tower 1, with its concrete segments 7 made up of several precast concrete elements 9, is simplified by the fact that the individual precast concrete elements 9 can be easily positioned and no complex connections of the vertical joints 8 or the precast concrete elements 9 of a concrete segment 7 are required. The assembly of the precast concrete elements 9 into concrete segments 7, and the assembly of the concrete segments 7 into a concrete tower section 3, without the need for grout, is facilitated by the high-precision manufacturing of the precast concrete elements 9 as identical parts. Due to the grout-free design of the horizontal and vertical joints, as well as the bondless guidance of the vertical tendons, the assembly, maintenance, and dismantling of the tower are simplified. The fixing of the vertical tendons 18 to the projection 25 contributes to the simple production of the concrete segments 7 or the precast concrete elements 9, as well as to the simple assembly of the tower section 3. Reference symbol list 1 tower 2 Foundation 3 Tower section made of concrete 4 tower sections made of steel 5 transition piece 6 Horizontal joint 7 concrete segments 8 Vertical joint 9 Precast concrete element 10 Outside 11 upper contact surface 12 lower contact surface 13 lateral contact surfaces 14 Contact area 15 Additional reinforcement 16 Inside 17 Sheathing tube 18 Vertical tendon 19 screw connection 20 screws 21 dowels 22 Recess for screw connection 23 Inner wall 24 Interior 25 lead H height B Width α Deflection angle QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 1 474 579 B1

[0003] EP 2 631 393 A1

[0004]

Claims

[1] Tower (1) for a wind turbine with at least one tower section (3) made of concrete, which is composed of several ring-shaped concrete segments (7) arranged one above the other, forming horizontal joints (6), wherein each concrete segment (7) is composed of at least two ring-segment-shaped precast concrete elements (9) arranged side by side, forming vertical joints (8), each having an outer surface (10), an inner surface (16) as well as an upper, a lower and two lateral contact surfaces (11, 12, 13), wherein the concrete segments (7) of the at least one tower section (3) are connected to each other in the vertical direction of the tower (1) by vertical tensioning devices, wherein the vertical joints (8) of each of two superimposed concrete segments (7) are offset from each other in the circumferential direction of the concrete segments (7), wherein a precast concrete element (9) of an upper concrete segment (7) of the two superimposed concrete segments (7) overlaps a vertical joint (8) of a lower concrete segment (7) of the two superimposed concrete segments (7), and wherein the superimposed concrete segments (7) are tensioned together by the vertical prestressing devices, in particular vertical tendons (18), in such a way that a load-bearing, friction-fit connection is created, characterized by , that the precast concrete elements (9) are manufactured as precision parts using formwork, which already achieve their ready-to-install final contour through casting, without the need for any further processing step, wherein the precast concrete elements (9) are preferably cast with such high accuracy that the upper contact surface (11) and the lower contact surface (12) are aligned exactly parallel to each other without post-processing, so that no tolerance compensation measures, in particular bonding the contact surfaces with mortar, are required as planned. [2] Tower (1) for a wind turbine with at least one tower section (3) made of concrete, which is composed of several ring-shaped concrete segments (7) arranged one above the other, forming horizontal joints (6), wherein each concrete segment (7) is composed of at least two ring-segment-shaped precast concrete elements (9) arranged side by side, forming vertical joints (8), each having an outer surface (10), an inner surface (16) as well as an upper, a lower and two lateral contact surfaces (11, 12, 13), wherein the concrete segments (7) of the at least one tower section (3) are connected to each other in the vertical direction of the tower (1) by vertical tensioning devices, wherein the vertical joints (8) of each of two superimposed concrete segments (7) are offset from each other in the circumferential direction of the concrete segments (7), wherein a precast concrete element (9) of an upper concrete segment (7) of the two superimposed concrete segments (7) overlaps a vertical joint (8) of a lower concrete segment (7) of the two superimposed concrete segments (7), and wherein the superimposed concrete segments (7) are prestressed together by the vertical prestressing devices, in particular vertical tendons (18), such that a load-bearing, friction-fit connection is created, characterized by , that the precast concrete elements (9) have additional reinforcement (15) at least at their upper end in an area lying below the vertical joint (8). [3] Tower (1) for a wind turbine with at least one tower section (3) made of concrete, which is composed of several ring-shaped concrete segments (7) arranged one above the other, forming horizontal joints (6), wherein each concrete segment (7) is composed of at least two ring-segment-shaped precast concrete elements (9) arranged side by side, forming vertical joints (8), each having an outer surface (10), an inner surface (16) as well as an upper, a lower and two lateral contact surfaces (11, 12, 13), wherein the concrete segments (7) of the at least one tower section (3) are connected to each other in the vertical direction of the tower (1) by vertical tensioning devices, wherein the vertical joints (8) of each of two superimposed concrete segments (7) are offset from each other in the circumferential direction of the concrete segments (7), wherein a precast concrete element (9) of an upper concrete segment (7) of the two superimposed concrete segments (7) overlaps a vertical joint (8) of a lower concrete segment (7) of the two superimposed concrete segments (7), and wherein the superimposed concrete segments (7) are prestressed together by the vertical prestressing devices, in particular vertical tendons (18), such that a load-bearing, friction-fit connection is created, characterized by , that the lateral contact surfaces (13) of the precast concrete elements (9) each have at least two raised contact areas (14) by means of which they contact a lateral contact area (14) of an adjacent precast concrete element (9) in the assembled state and that the precast concrete elements (9) of each concrete segment (7) are connected to each other by horizontal tensioning devices, wherein the horizontal clamping means are preferably designed as screw connections (19) and the screw connection points are accessible from the inside (16) via recesses (22), so that the screw connections (19) can be easily attached or, if necessary, easily removed. [4] Tower according to one of claims 1 to 2, characterized by , that the precast concrete elements (9) of each of a concrete segment (7) are connected to each other only by means of the frictional connection by means of the precast concrete element (9) that crosses the vertical joint (8). [5] Tower according to one of claims 1 to 2, characterized by , that at least the lateral contact surfaces (13) of the precast concrete elements (9) are flat and butt against each other to form the vertical joints (8). [6] Tower according to any one of the preceding claims, characterized by that the precast concrete elements (9) also have additional reinforcement (15) at their lower end, in particular in a central area. [7] Tower according to any one of the preceding claims, characterized by , that the precast concrete elements (9) of each of a concrete segment (7) are connected to each other by horizontal tensioning devices and / or tension connecting devices, in particular screw connections (19), wherein the screw connections (19) are preferably designed in such a way that they serve as assembly aids in the manufacture of the tower (1) and / or serve to absorb extreme loads. [8] Tower according to any one of the preceding claims, characterized by that the concrete segments (7) are composed of at least three, preferably four, ring-segment-shaped precast concrete elements (9) designed as identical parts. [9] Tower according to any one of the preceding claims, characterized by, that the height (H) of the ring-shaped precast concrete elements (9) is less than the width (B) of the ring-shaped precast concrete elements (9), wherein preferably the height (H) of the ring-shaped precast concrete elements (9) is less than one third, preferably less than one quarter, of the width (B) of the ring-shaped precast concrete elements (9). [10] Tower according to the preceding claim, characterized by that the height (H) of the ring-shaped precast concrete elements (9) is less than 3 m, particularly preferably less than 2.5 m. [11] Tower according to any one of the preceding claims, characterized by , that the vertical tendons (18) are unbonded and guided outside a concrete cross-section of the precast concrete elements (9).

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