The invention relates to a method for producing a deck slab using a conveyor device with a top concrete layer produced at the installation site for a bridge as well as deck slabs produced according to this method.
The production of a deck slab for a bridge using a formwork carriage is described in the “Handbuch Brücken”, section 9.3.2 “Schalung and Fertigung Betonfahrbahnplatte”, published by Gerhard Mehlhorn with the Springer-Verlag in the year 2010. There are mounted support constructions on the longitudinal bridge girder. On the top surface of the support construction, there are installed launching gantries, which provide movement of a formwork carriage in the longitudinal direction of the bridge. For the production of a construction section of the deck slab, the formwork carriage is conveyed to the installation site, being fixed there. Subsequently, the formwork for the construction section to be erected of the deck slab is moved into the scheduled position, the reinforcement is laid and concrete is being introduced. After the concrete has hardened, the formwork is then lowered and the formwork carriage is moved to a further installation site. A construction section usually has a length of 15 m to 35 m. An advantage of this method is that in the final condition, there will be present only a few sectional joints within the deck slab. A disadvantage of this method is the slow construction progress as the assembly of the formwork and the laying of the reinforcement are carried out at the installation site and the formwork will only then be removed from the formwork carriage if the concrete of the construction section last produced has sufficient rigidity. The production of the construction sections using this method is usually realized within one week, wherein the weekend is used for the concrete to harden.
The production of the deck slab for a bridge using a formwork carriage, which may be moved directly on the longitudinal bridge girder, is described in the DE 195 44 557 C1. In this method, the effort for producing the support constructions and for mounting the launching gantries is being omitted. Also in this method, there is given the disadvantage of the slow construction progress of a weekly schedule for the production of a construction section of the deck slabs.
In DE 25 20 105 A1 there are described prefabricated elements made from reinforced concrete, which are composed of a prefabricated bottom slab and at least one cross beam. In the prefabricated bottom slab, there are arranged the lower transverse reinforcement and the lower longitudinal reinforcement of the deck slab. The prefabricated elements are moved at the installation site using a crane onto the longitudinal bridge girder. Then the splice reinforcement for the lower longitudinal reinforcement, the upper longitudinal reinforcement and the upper transverse reinforcement is being laid. In the next operation, the top concrete layer is then applied. Moving the prefabricated elements at the installation site, sealing the joints in-between the individual prefabricated elements and laying of the reinforcement are time-consuming operations, which is disadvantageous for a fast construction progress in the production of the deck slab.
To accelerate construction progress, there is described in WO/2016/187634 A1 a method for producing a deck slab having prefabricated bottom slabs and a top concrete layer arranged above made from in-situ concrete for a bridge having a longitudinal bridge girder. In this method there is produced a conveyor device, which may be moved on support constructions, which are mounted on the top surface of the longitudinal bridge girder, in the longitudinal direction of the bridge. Using the conveyor device, the prefabricated slabs are transported from an assembly site to an installation site. At the installation site, the prefabricated slabs are lowered until the edges of the prefabricated slabs are supported on the longitudinal bridge girder. Upon lowering, the prefabricated slabs are still attached at the conveyor device by means of tendons. Subsequently, there is laid a reinforcement and a top concrete layer is applied. After the top concrete layer has hardened, the anchors of the prefabricated slabs are then removed from the tendons. Subsequently, the conveyor device is then moved to an assembly site to optionally pick up further prefabricated slabs. The disadvantage of the method described in WO/2016/187634 A1 is the anchoring of the tendons within the prefabricated slabs. The load capacity of the anchors of the tendons is low if anchoring of the tendons is realized within the prefabricated slabs. The load capacity of the anchors of the tendons is sufficient if anchoring of the tendons is realized at the bottom surface of the prefabricated slabs. Anchoring at the bottom surface of the prefabricated slabs, however, requires an additional operation for removing the anchors from the bottom surface of the prefabricated slabs. In the method described in WO/2016/187634 A1 it is furthermore disadvantageous that the forces arising within the tendons cause bending moments within the prefabricated slabs, which lead to high bending stress within the thin prefabricated slabs. A further disadvantage of the method described in WO/2016/187634 A1 is that the tendons may only be removed from the conveyor device after the top concrete layer has sufficient rigidity. Awaiting the hardening phase of the top concrete layer is disadvantageous for a rapid construction progress in the production of the deck slab.
Also the documents AT 520 614 A1 and KR 101 866 466 B each show methods for the production of deck slabs of a bridge. There are respectively positioned slab-like elements onto longitudinal girders of the bridge, whereupon a reinforce concrete slab will be produced thereon. The methods of these publications have the same disadvantages as the method of the publication WO/2016/187634 A1.
The publication JP 2004 116060 A discloses a method, in which there are laid prefabricated cross beams made from reinforced concrete on a longitudinal bridge girder in order to produce a deck slab. Subsequently, there are laid prefabricated slabs made from reinforced concrete on the cross beams. In the next work step, a reinforcement is laid on the prefabricated slabs and then there is applied a top concrete layer. Laying the individual cross beams and subsequently laying the individual prefabricated slabs at the installation site is time consuming and, hence, disadvantageous for a rapid construction progress.
It is thus the task of the present invention to create a method for the production of a deck slab, which provides for a faster construction progress than with methods known performing formwork and/or reinforcement works at the installation site and in which in the construction condition an easier anchoring of the tendons is possible and in which the bending stress arising in the construction condition may be better absorbed than with the method known using prefabricated bottom slabs.
The task is solved by a method for the production of a construction section of a deck slab for a bridge, wherein:
- a—there is produced at an assembly site from reinforced concrete a bottom layer composed of at least one segment and having cross beams, which are arranged at an angle of between 70° and 90° to a longitudinal axis of a longitudinal bridge girder;
- b—the bottom layer having the cross beam is transported for the construction section of the deck slab using at least one conveyor device from the assembly site to an installation site and lowered into an installation position;
- c—there is laid onto the bottom layer having the cross beams a top concrete layer for the construction section of the deck slab, wherein there is optionally laid a reinforcement to be arranged within the top concrete layer before the application of the top concrete layer;
- d—the bottom layer having the cross beam is removed for the construction section of the deck slab from the conveyor device before or after the application of the top concrete layer.
- e—the conveyor device is moved away from the installation site and optionally conveyed to the assembly site in order to pick up there a further bottom layer having cross beams for a construction section of the deck slab.
To accelerate constructional progress, it may be advantageous to configure the bottom layer having the cross beams or a segment of the bottom layer to be load-bearing such that it may absorb its own weight and the weight of the top concrete layer and introduce these into the longitudinal bridge girder. In this case, the conveyor device may be moved away from the installation site immediately upon lowering of the bottom layer.
To enlarge the load capacity of the bottom layer, there are arranged cross beams within the bottom layer. These cross beams may be laid at the assembly site onto a formwork or a scaffolding before the production of the bottom layer. The cross beams are advantageously equipped with starter bars. In this way, a load-bearing connection of the cross beams to the bottom layer and the top concrete layer is being ensured. There may be arranged anchors for lifting the bottom layer and cladding tubes for tendons within the cross beams. The cross beams may be equipped with steel slabs to provide for a structural steel connection of the cross beams to the bottom layer or of cross beams, which are arranged in different segments. The connection between cross beams and prefabricated slabs or between two cross beams, respectively, which are arranged in different segments of the bottom layer, may be produced by welding, screwing or by starter bars and hardcore filling.
There may be arranged terminal anchors and deflection points for tendons in a cross beam. It may be advantageous to produce the top concrete layer in two operations. The second part of the top concrete layer is only produced after the first part of the top concrete layer has reached a predefined minimum rigidity. In this case, the bottom layer may be removed from the conveyor device, after the first part of the top concrete layer has reached a predefined minimum rigidity. The bottom layer may be produced having haunches and variable thickness. A segment of a bottom layer may be shifted transversally to the longitudinal axis of the longitudinal bridge girder and/or rotated in regard thereto after it has been raised at the assembly site, may be transported from the assembly site to the installation site in this shifted and/or rotated position and may then be installed at the installation site by cross shift and/or rotation into the scheduled installation position. It may be advantageous to transport the segments of the bottom layer for a construction section of the deck slabs in several transport operations from the transfer site to the installation site.
In an particularly advantageous embodiment of the present invention there is connected a bottom layer composed of at least two segments and having cross beams at the assembly site by a first top concrete layer or by other means such as, for example, screw connections, to a bottom layer composed of one segment.
In a particularly advantageous embodiment of the present invention the bottom layer having cross beams is produced at the assembly site from a segment and transported using a conveyor device composed of a front part, a rear part and at least two longitudinal girders from the assembly site to the installation site. The front part and the rear part of the conveyor device are connected to one another by means of the at least longitudinal girders. The conveyor device is moved along the bridge on support constructions. The bottom layer having the cross beams during transport from the assembly site to the installation site is arranged between the front part and the rear part and underneath the longitudinal girder of the conveyor device. Underneath the bottom layer having cross beams, there must not be arranged any constructions elements for connecting the front part and the rear part of the conveyor device during the lowering operation at the installation site. During the transport of the bottom layer from the assembly site to the installation site, it may be useful to connect the front and the rear part of the conveyor device by way of construction elements such as, e.g., ropes, which are arranged underneath the bottom layer having the cross beams, in order to enlarge the rigidity of the conveyor device.
In a preferred embodiment of the invention the conveyor device is produced from a front part, a rear part and at least two longitudinal girders. To shift the conveyor device in order to enable the production of the next construction section of the deck slab, the front part and the rear part of the conveyor device are moved on support constructions. The front and the rear part of the conveyor device are connected to one another by at least two longitudinal girders. At the longitudinal girders, there is installed a construction by means of which lifting and/or lowering of the bottom layer having cross beams, which is arranged between the front and the rear part and underneath the longitudinal girders of the conveyor device, is made possible.
The conveyor device may be configured as a frame construction or as a truss construction.
Using the method according to the invention it is made possible to produce the deck slab of bridges that are straight in plan view and have any curvature. Using the method according to the invention it is made possible to produce deck slabs having any transversal inclination and having variable width.
In a further aspect of the invention there is created a construction section of a deck slab, comprising a bottom layer composed of at least one segment and having cross beams, which are arranged at an angle of between 70° and 90° to the longitudinal axis of a longitudinal bridge girder, wherein the bottom layer is produced from reinforced concrete and wherein onto the bottom layer having cross beams there is applied a top concrete layer for the construction section of the deck slab, which optionally has reinforcement.
Further details, features and advantages of the invention become obvious from the explanations given below of exemplary embodiments schematically depicted in the drawings FIG. 1 to FIG. 39. The drawings show:
FIG. 1 a view of a first embodiment according to the invention after cross beams have been laid on a framework at an assembly site;
FIG. 2 a view of the first embodiment according to the invention after the bottom layer has been produced for a construction section of the deck slab on the framework;
FIG. 3 a view of the first embodiment according to the invention while the conveyor device is conveyed to the assembly site;
FIG. 4 a view of the first embodiment according to the invention while the bottom layer having cross beams is lowered for a construction section of the deck slab at the installation site;
FIG. 5 a vertical sectional view according to the section plane V-V indicated in FIG. 4;
FIG. 6 a vertical sectional view according to the section plane V-V indicated in FIG. 4 after the bottom layer has been lowered at the installation site;
FIG. 7 the detail A of FIG. 5;
FIG. 8 the detail B of FIG. 6;
FIG. 9 a view of the first embodiment according to the invention after the top concrete layer has been applied;
FIG. 10 a view of the first embodiment according to the invention when the conveyor device is moved from the installation site to the assembly site;
FIG. 11 a longitudinal view of the first embodiment according to the invention after the bottom layer having cross beams has been produced for a construction section of the deck slab at the assembly site;
FIG. 12 a longitudinal view of the first embodiment according to the invention after the bottom layer having cross beams has been deposited at the installation site;
FIG. 13 a longitudinal view of the first embodiment according to the invention after the deck slab has been completed;
FIG. 14 a view of a second embodiment according to the invention after the bottom layer composed of three segments and having cross beams has been produced on a formwork at an assembly site;
FIG. 15 a view of the second embodiment according to the invention after the three segments of the bottom layer having cross beams have been lowered at the installation site;
FIG. 16 a longitudinal view of the second embodiment according to the invention after a bottom layer having cross beams has been produced at the assembly site;
FIG. 17 a longitudinal view of the second embodiment according to the invention after the bottom layer having cross beams has been deposited at the installation site;
FIG. 18 a longitudinal view of the second embodiment according to the invention after the deck slab has been completed;
FIG. 19 a vertical sectional view of a third embodiment according to the invention while the bottom layer having cross beams is transported from the assembly site to the installation site;
FIG. 20 a vertical sectional view of the third embodiment according to the invention after the bottom layer having the cross beams has been lowered onto the longitudinal bridge girder and after the top concrete layer has been produced;
FIG. 21 the detail C of FIG. 19;
FIG. 22 the detail D of FIG. 20;
FIG. 23 a vertical sectional view of a fourth embodiment according to the invention after the bottom layer having cross beams has been lowered at the installation site;
FIG. 24 a vertical sectional view of the fourth embodiment according to the invention after the conveyor device has been removed from the installation site;
FIG. 25 a vertical sectional view of the fourth embodiment according to the invention after a first top concrete layer has been produced;
FIG. 26 a vertical sectional view of the fourth embodiment according to the invention after the second top concrete layer has been applied;
FIG. 27 the detail E of FIG. 23;
FIG. 28 a sectional view along the line XXVIII-XXVIII of FIG. 27;
FIG. 29 the detail F of FIG. 23;
FIG. 30 a sectional view along the line XXX-XXX of FIG. 29;
FIG. 31 a view of a fifth embodiment according to the invention after three prefabricated segments of the bottom layer having cross beams have been laid at the assembly site;
FIG. 32 a view of the fifth embodiment according to the invention after a first top concrete layer has been applied at the assembly site;
FIG. 33 a view of the fifth embodiment according to the invention while the bottom layer having cross beams and a first top concrete layer for a construction section of the deck slab are transported from the assembly site to the installation site;
FIG. 34 a view of the fifth embodiment according to the invention after the bottom layer having cross beams and a first top concrete layer for a construction section of the deck slab has been lowered at the installation site;
FIG. 35 a longitudinal view of the fifth embodiment according to the invention immediately before the bottom layer having cross beams and the first top concrete layer for a construction section of the deck slab is lifted at the assembly site;
FIG. 36 a longitudinal of the view of the fifth embodiment according to the invention after the bottom layer having cross beams and a first top concrete layer for a construction section of the deck slab has been deposited at the installation site;
FIG. 37 a longitudinal view of the fifth embodiment according to the invention after the deck slab has been completed;
FIG. 38 a view of a sixth embodiment according to the invention while the bottom layer having cross beams is transported for a construction section of the deck slab from the assembly site to the installation site and
FIG. 39 a view of a sixth embodiment according to the invention after the bottom layer having cross beams has been deposited for a construction section of the deck slab at the installation site.
The first embodiment of the method according to the invention is depicted in the FIGS. 1 to 13. According to FIG. 1, there is erected at the assembly site 31 a formwork 23 on mounting girders 20. The top surface of the formwork 23 has the same shape as a bottom surface 19 of a bottom layer 2 of a construction section. In this exemplary embodiment, in the first method step, the lower longitudinal and transverse reinforcement for the first construction section are laid on the formwork 23. For reasons of clarity, and because the embodiment of the reinforcement of deck slabs 1 having a top concrete layer 3 can be assumed as known, the reinforcement is not depicted in this exemplary embodiment. Subsequently, there are positioned on the formwork 23 three cross beams 21, which are pre-fabricated as prefabricated beams 27. The cross beams 21 are in this example arranged at an angle of 90° to the longitudinal axis of the bridge 4. In another embodiment example it would be possible that the cross beams were arranged at an angle of 80° to the longitudinal axis of the bridge. The cross beams 21 may preferably be produced from reinforced concrete.
In the longitudinal direction of the bridge 4, there are shifted longitudinal edge beams 28 to simplify in a later method step the concreting works when introducing the top concrete layer 3. The cross beams 21 as well as the longitudinal edge beams 28 are equipped with starter bars. The deck slab 1 in this embodiment example has two haunches in the final condition.
These haunches are to be reproduced already in the production of the cross beams 21 and in the production of the formwork 23.
In the next method step, concrete for the production of the bottom layer 2 is introduced according to FIG. 2. The lower longitudinal and transverse reinforcement 27 as well as the starter bars of the prefabricated beams 27 are then embedded in concrete. The bottom layer 2 is in this example produced having a constant thickness. It would also be possible to produce the bottom layer 2 having a variable thickness in order to reduce the weight of the bottom layer 2 for a construction section of the deck slab. The bottom layer 2 for the first construction section has eight recesses 16.
According to FIG. 3, a conveyor device 10 is moved in the next method step on a longitudinal bridge girder 5 to the assembly site 21. The longitudinal bridge girder 5 in the first embodiment example is composed of two steel girders 9. The steel girders 9 may be connected by transverse bracing or transverse girders, which are not depicted in this embodiment example for reasons of clarity. The conveyor device 10 is in this example composed of a spatial frame construction 49 made from steel. Alternatively, the conveyor device 10 could also be composed of a truss construction. The conveyor device 10 has eight wheels 8. Moving the conveyor device 10 is realized by a rolling process of the wheels 8 in the two lanes 7 configured on the top surface 18 of the longitudinal bridge girder 5. The two lanes 7 are each arranged in-between the bracing means 6. The conveyor device 10 may advantageously be moved to the assembly site 31 only after the reinforcement has been laid, the prefabricated beams 27 have been shifted and the concrete for the bottom layer 2 has been introduced, as the laying of the reinforcement supported by a crane and the shifting of the prefabricated beams 27 as well as the introducing of the concrete for the bottom layer 2 carried out by means of a concrete pump would be easier to realize. At the assembly site 31, additional means may make it possible that the conveyor device may drive across the cross beams 21 and the reinforcement.
The bottom layer 2 having the cross beams 21 and the longitudinal edge beams 28 is lifted from the conveyor device 10 after the concrete has hardened and is then transported from the assembly site 31 to the installation site 32.
FIG. 4 shows in a view that the bottom layer 2 is lowered at the installation site 32. In FIG. 4, there is depicted a state immediately before supporting the bottom layer 2 onto the longitudinal bridge girder 5. The weight of the bottom layer 2 having the cross beams 21 is in this condition introduced by the tendons 11 into the conveyor device 10. The bottom layer 2 having the cross beams 21 and the longitudinal edge beams 28 may be classified as a ribbed base plate 26 in a statics point of view. The net weight of the bottom layer 2 is introduced via a structural bending action in the bottom layer 2 into the cross beams 21 and in the edge regions also partly into the longitudinal edge girders 28. The cross beams 21 absorb the weight of the bottom layer 2 and of the longitudinal edge girder 28 and transmit it to the anchors 14. Within the anchors 14, the net weight of the ribbed base plate 26 is transmitted to the lower end points 13 of the tendons 11.
The upper end points 12 of the tendons 11 are attached to the conveyor device 10. The conveyor device 10 is positioned at the installation site 32 such that the recesses 16 are arranged above the bracing means 6 arranged at the top surface 18 of the longitudinal bridge girder 5. The wheels 8 may be blocked after the precise positioning of the conveyor device 10 at the installation site 32 to prevent the conveyor device 10 from rolling away. Fixing the conveyer device 10 at the installation site 32 may also be realized by way of a temporary connection of the conveyor device 10 to the longitudinal bridge girder 5 or by other measures.
In FIG. 5 there is depicted a vertical section through the conveyor device 10 positioned at the installation site 32. The ribbed base plate 26 is situated at a superelevated position, as during the movement of the conveyor device 10 from the assembly site 31 to the installation site 32 there should be prevented any collision with the bracing means 6. The wheels 8 of the conveyor device 10 are arranged in the lanes 7 configured between the bracing means 6 on the top surface 18 of the longitudinal bridge girder 5. The weight of the conveyor device 10 and of the ribbed base plate 26 is transmitted from the wheels 8 to the longitudinal bridge girder 5.
A sectional view corresponding to FIG. 5 after the ribbed base plate 26 has been lowered is depicted in FIG. 6. After being lowered, the ribbed base plate 26 is supported on the longitudinal bridge girder 5. Depending on the basic geometrical dimensions of the ribbed base plate 26, the configuration of the reinforcement and the dimensions of the cross beams 21, the ribbed base plate 26 may be supported on the longitudinal bridge girder 5 in such a way that the tendons 11 will be completely relieved. It would, however, also be possible to support the ribbed base plate 26 on the longitudinal bridge girder 5 in such a way that only a part of the weight of the ribbed base plate 26 is supported on the longitudinal bridge girder 5 and that the remaining part of the weight of the ribbed base plate 26 is absorbed by the tendons 11 and introduced into the conveyor device 10.
FIG. 7 shows in a detailed view a wheel 8 of the conveyor device 10, which is arranged between the bracing means 6 in a lane 7 on the top surface 18 of longitudinal bridge girder 5. Strips 22 are adhered onto the top surface 18 of the longitudinal bridge girder 5. The strips 22 may, for example, be made from an elastomeric material. In a cross beam 21, there is installed an anchor 14 for connection to the lower end point 13 of a tendon 11. This anchor 14 is composed of a steel slab 35 and a threaded nut 36, which is welded to the top surface of the steel slab 35. At the outer surface of the threaded nut 36 there is attached a sleeve tube 37. At the lower end point 13 of the tendon 11 there is configured a thread providing for attachment of the tendon 11 within the anchor 14.
FIG. 8 shows a detailed view corresponding to FIG. 7 after the ribbed base plate 26 has been lowered and the ribbed base plate 26 has been supported on the top surface 18 of the longitudinal bridge girder 5. When transmitting the weight of the ribbed base plate 26 from the conveyor device 10 onto the longitudinal bridge girder 5, the strips 22 are pressed together. Pressing these strips 22 together makes it possible to compensate for any constructional inaccuracy between the bottom surface 19 of the bottom layer 2 and the top surface 18 of the longitudinal bridge girder 5. A second important function of the strips 22 is the production of a sealing between the bottom surface 19 of the bottom layer 2 and the top surface 18 of the longitudinal bridge girder 5. The gap 24 between the bottom surface 19 of the bottom layer 2 and the top surface 18 of the longitudinal bridge girder 5 corresponding in height to the thickness of the strips 22 pressed together should be filled with grout or concrete to ensure protection against corrosion of the top surface 18 of the longitudinal bridge girder 5.
According to FIG. 9, a top concrete layer 3 is applied onto the lowered ribbed base plate 26. The surface of the ribbed base plate 26 should be made as rough as possible such that there is given rise to a good bracing effect within the joint between the ribbed base plate 26 and the top concrete layer 3. The weight of the top concrete layer 3 is in this working step transmitted to a smaller extent via the structural bending action of the ribbed base plate 26 to the two steel girders 9 of the longitudinal bridge girder 5 and to a larger extent via the tendons 11 into the conveyor device 10. The weight of the top concrete layer 3 that is absorbed by the conveyor device 10 will be introduced via the wheels 8 into the longitudinal bridge girder 5.
According to FIG. 10, there is installed in the next step a device 15 for moving the conveyor device 10 on the top concrete layer 3, once the top concrete layer 3 has reached a predetermined minimum rigidity. Then in the next step of the method according to the invention the tendons 11 are disassembled. A complete disassembly of the tendons 11, which is depicted in FIG. 10, is not absolutely essential. Releasing the connections between the lower end points 13 of the tendons 11 and the anchors 14 installed in the ribbed base plate 14 is sufficient to introduce the entire weight of the deck slab 1 via a structural bending action into the longitudinal bridge girder 5 and to relax the conveyor device 10. Following the transfer of weight of the ribbed base plate 26 and the top concrete layer 3, which together form a construction section of the deck slab 1, the weight of the conveyor device 10 is shifted from the wheels 8 onto the device 15 for moving the conveyor device 10 on the second top concrete layer 3. This shift may, for example, as depicted in FIG. 10, be realized by lifting and turning over the wheels 8. Subsequently, the conveyor device 10 may be moved by means of the device 15 for moving the conveyor device 10 on the top concrete layer 3 to the assembly site 31 to optionally pick up there a further ribbed base plate 26.
A bridge 4, which comprises two abutments 33, five pillars 34 and one longitudinal bridge girder 5, is depicted in FIG. 11 to FIG. 13. The conveyor device 10 is moved by way of winches to the assembly site 31, which is here arranged above one of the two abutments 33. At the assembly site 31, the ribbed base plate 26, which is composed of the bottom layer 2, the cross beams 21 and the longitudinal edge beams 28, is attached at the conveyor device 10 by means of tendons 11. The ribbed base plate 26 is lifted to prevent any contact with the bracing means 6 mounted on the longitudinal bridge girder 5 when the conveyor device 10 is moved in the longitudinal direction of the bridge 4 and to make it possible that a construction section already completed of the deck slab 1 may be driven on. To make it possible to drive over the construction sections already completed of the deck slab 1 it is necessary to install the device 15 for moving the conveyor device 10 on a top concrete layer 3.
According to FIG. 12 the conveyor device 10 and the ribbed base plate 26 attached thereto are moved in the next method step from the assembly site 31 to the projected installation site 32. At the installation site 32, the ribbed base plate 26 is lowered until the bottom layer 2 rests on the top surface 18 of the longitudinal bridge girder 5. Then the top concrete layer 3 may be applied. After the top concrete layer 3 has hardened, there is installed a device 15 for moving the conveyor device 10 on the top concrete layer 3, the tendons 11 are released from the anchors 14 in the prefabricated slabs 2 and the conveyor device 10 is conveyed to the assembly site 31 such that the ribbed base plate 26 may there be received for the next construction section.
In this embodiment example, the ribbed base plate 26 is attached to the conveyor device 10 by means of tendons 11, while the top concrete layer 3 is being applied. Only once the top concrete layer 3 has hardened, the ribbed base plate 26 is removed from the conveyor device 10. Alternatively, it would also be possible to configure the ribbed base plate 26 to be so rigid such that it would be able to carry its own net weight and the weight of the top concrete layer 2. A ribbed base plate 26 such configured would make it possible that the connection between the ribbed base plate 26 and the conveyor device 10 is released immediately after the ribbed base plate 26 has been lowered and the conveyor device 10 could be moved back to the assembly site 31. This would enable the acceleration of the production of the deck slab 1. In this case, however, there should be installed makeshift lanes 7 on the ribbed base plate 26 such that it would be possible for the conveyor device 10 to drive on the ribbed base plate 26.
The assembly site 31 is in the first embodiment example situated on an abutment 33. It may also be advantageous to move the assembly site 31 onto the bridge 4, after the first sections of the deck slab 1 have been produced. It may also be advantageous to provide more than one assembly site 31 to enable longer hardening of the concrete of the bottom layer 2. According to FIG. 13, the remaining sections of the deck slab 1 of the bridge 4 are produced using the method according to the invention. Subsequently, the bridge 4 is then completed in the usual manner by applying a sealing onto the surface of the top concrete layer 3 and by subsequently applying a deck cover.
In this exemplary embodiment, the weight of the ribbed base plate 26 on the top concrete layer 3 is introduced from the wheels 8 into the longitudinal bridge girder 5. Alternatively, it would also be possible to install supports and to lift the wheels 8 before the top concrete layer 3 is introduced. This may also be of advantage as the supports may be accommodated in the recesses 16 having smaller dimensions than the recesses 16 required for the accommodation of the wheels 8.
A second embodiment of the method according to the invention is depicted in the FIGS. 14 to 18. According to FIG. 14, there are produced on an assembly site 31 on a framework 23 three segments 17 of a bottom layer 2 having cross beams 21, which are arranged in the transverse direction in regard to the longitudinal axis of the longitudinal bridge girder 5. In the three segments 17 of the bottom layer 2, there are contained the lower longitudinal and transverse reinforcement, the shear reinforcement and a part of the upper longitudinal and transverse reinforcement. For reasons of clarity, the reinforcement is not depicted in this embodiment example. Support constructions 29 are arranged between the segments 17. The support constructions 29 are composed of steel tubes welded to the mounting girders 20. At the upper end points of the support constructions 29, there are mounted launching gantries 30. The launching gantries 20, for example, are configured as roller bearing or slide bearing such that a conveyor device 30 may be shifted on the launching gantries 30 in the longitudinal direction along the longitudinal bridge girder 5 and on the assembly site 31.
After the concrete of the bottom layer 2 has hardened, a conveyor device 10 will be moved to the assembly site 31, the three segments 17 of the bottom layer 2 will be attached using tendons 11 to the conveyor device 10, will be lifted and transported to the installation site 32. According to FIG. 15, the three segments 17 of the bottom layer 2 are lowered at the installation site 32 in such a way that the edges of the segments 17 are supported on the steel girders 9 of the longitudinal bridge girder 5.
FIG. 15 shows that there are formed by the three segments 17 of the bottom layer 2 two cantilevering slabs and a slab arranged between the two steel girders 9 of the longitudinal bridge girder 5. These three slabs should be separated from one another to make it possible to convey the conveyor device 10 in the longitudinal direction of the bridge 4 and to lower the bottom layer 2.
For this reason it is also not possible to lay the entire reinforcement at the assembly site 31. The upper transverse reinforcement required for connecting the cantilevering slabs and the slab arranged between the steel girders 9 of the longitudinal bridge girder 5 may only be laid at the installation site 32 after the bottom layer 2 has been lowered.
A bridge 4 comprising two abutments 33, five pillars 34 and one longitudinal bridge girder 5 is depicted in the illustrations FIGS. 16 to 18. As shown in FIG. 16, the support constructions 29 are mounted on the longitudinal bridge girder 5 and on the assembly site 31, which is situated on one of the two abutments 33. The conveyor device 10, which is configured as a spatial frame construction 49, is moved with the aid of winches to the assembly site 31, which is here arranged above one of the two abutments 33. At the assembly site 31, the bottom layer 2 is attached by means of tendons 11 to the conveyor device 10. The bottom layer 2 is mounted in a lifted superelevated position to prevent any contact with the bracing means 6 mounted on the longitudinal bridge girder 5 when conveying the conveyor device 10 in the longitudinal direction of the bridge 4 and to make it possible to drive on the top concrete layer 3 of construction sections already completed of a deck slab 1.
According to FIG. 17, the conveyor device 10 and the bottom layer 2 suspended therefrom are moved from the assembly site 31 to the scheduled installation site 32 in the next method step. At the installation site 32, the bottom layer 2 is lowered until the edges of the segments 17 of the bottom layer 2 rest on the upper flanges of the steel girders 9 of the longitudinal bridge girder 5. Then the top concrete layer 3 may be applied. After the top concrete layer 3 has been hardened, the tendons 11 are released from the bottom layer 2 and the conveyor device 10 is conveyed to the assembly site 31, such that the bottom layer 2 may be mounted for the next construction section at the conveyor device 10.
The assembly site 31 is situated in this embodiment example on an abutment 33. It may also be advantageous that the assembly site 31 is moved to the bridge 4 after the first sections of the deck slab 1 have been produced.
According to FIG. 18 all support constructions 29 are removed after the production of the deck slab 1 by cutting off the steel profiles in the vicinity of the surface of the top concrete layer 3. Subsequently, the bridge 4 is completed in the usual manner by applying a sealing onto the surface of the top concrete layer 3 and by subsequently applying a deck cover.
A third embodiment of the method according to the invention is depicted in the illustrations FIGS. 19 to 22.
FIG. 19 shows a vertical section through a conveyor device 10, which is configured as a spatial frame construction 49, and through a bottom layer 2 composed of three segments 17, during the transport from the assembly site 31 to the installation site 32. The conveyor device 10 is moved on launching gantries 30, which are mounted on support constructions 29. The three segments 17 of the bottom layer 2 are produced at the assembly site 31 having cross beams 21. Within the cross beams 21, there are installed cladding tubes 38, which are installed in the bracing wire produced in a later step.
During transport to the installation site 31, the segment 17 arranged between the steel girders 9 is in a raised position to prevent collision with the bracing means 6 welded to the steel girders 9 and the construction sections already completed of the deck slab 1. The segment 17 depicted in FIG. 19 at the left hand-side is in a raised and laterally shifted outwards position during the transport of the bottom layer 2 to the installation site 32 in order prevent a collision of the cross beams 21 with the support constructions 28 and the bracing means 6. The segment 17 depicted in FIG. 19 at the left-hand side is in a raised and turned position during the transport of the bottom layer 2 to the installation site 32 to prevent a collision of the cross beams 21 with the support construction 29 and the bracing means 6.
At the installation site 32, the three segments 17 of the bottom layer 2 are brought into the scheduled position. According to FIG. 20, there is required lowering the segment 17 arranged in-between the steel girders 9, lowering and shifting transversally to the right the segment 17 arranged in FIG. 19 at the left-hand side as well as lowering and turning the segment 17 arranged in the FIG. 19 at the right-hand side. The scheduled position depicted in FIG. 20 is reached when the upper edges of the cross beams 21 are in a horizontal position and when the front faces of the cross beams 21 touch. Using the method according to the invention it is also possible to reach a different position of the segments, for exampling having a constant transversal inclination, in the scheduled final position.
According to FIG. 21, a conveyor device 10 is mounted on launching gantries 30. The launching gantries 30 are, for example, configured as roller bearings or as sliding bearings such that the conveyor device 10 may be shifted in the longitudinal direction along the longitudinal bridge girder 5 of the bridge 4. The launching gantries 30 are attached at the upper end points of support constructions 29. The support constructions 29, which herein are configured as steel profiles, are connected in a flexurally rigid manner to the upper flanges of the steel girders 9 of the longitudinal bridge girder 5. The bottom layer 2 is depicted in FIG. 21 in a raised or superelevated, respectively, position and in FIG. 2 in a lowered position. In the superelevated position, the bottom layer 2 should be raised so much so that it is possible to drive on the bracing means 6 and the top concrete layer 3 of construction sections already completed. In the lowered position according to FIG. 22, the wheels of the bottom layer 2 are supported on the upper flanges of the steel girders 9 of the longitudinal bridge girder 5. FIG. 21 shows that within the cross beams 21, which are connected to the segments of the bottom layer 2, there are arranged cladding tubes 38.
According to FIG. 22, the segment depicted at the left-hand side of FIG. 19 of the bottom layer 2 is moved as far to the right until the front faces of the cross beams 21 touch one another. If the front faces of the cross beams 21 have been very accurately produced or post-finished, then contact splice may be performed. Alternatively, also the production of a splice connection with a coupling of the cladding tubes 38 and a grouting joint would be possible. After the segments of the bottom layer 2 have been accurately aligned, the top concrete layer 3 is produced. Subsequently, bracing wires 39 are inserted into the cladding tubes 38. By tensioning the bracing wires 39, a transverse preload may be applied onto the deck slab 1.
According to FIG. 22, the steel profiles of the support constructions 29 are embedded into concrete when applying the top concrete layer 3. The tendons 11 are protected by means of a sheath tube 37 against direct contact with the top concrete layer 3. This enables removal of the tendons 11 after the top concrete layer 3 has been hardened and re-use of the tendons 11 in the next construction section. The steel profiles are cut off in the vicinity of the surface of the top concrete layer 3 after the top concrete layer 3 has been hardened and the launching gantries 30 have been disassembled.
A fourth embodiment of the method according to the invention is depicted in the illustrations FIGS. 23 to 30.
FIG. 23 shows a vertical section through a conveyor device 10, which is configured as a spatial frame construction 49, and a bottom layer 3 composed of three segments 17 at the installation site 32. The three segments 17 of the bottom layer 2 are attached at the conveyor device 10 by means of tendons 11. The segments 17 are in this embodiment example not supported on the longitudinal bridge girder 5 composed of two prestressed concrete beams 40 but rather positioned next to the prestressed concrete beams 40. This has the advantage that the longitudinal bridge girder 5 may be configured having a larger statically effective depth. After the bottom layer 2 having cross beams 21 has been positioned as scheduled, the three segments 17 are connected to one another via the prestressed concrete beams 40 by means of structural steel connections. In order to realize the structural steel connection, there are installed steel panels 42 within the cross beams 21. At the installation site 32, these steel panels 42 are connected to one another in a flexurally rigid manner with additional steel panels 35 and screw connections 41. After the three segments 17 have been connected in a flexurally rigid manner, the tendons 11 are relaxed and dismantled. The conveyor device 10 is no longer required at the installation site 32 and may be moved back to the assembly site 31.
FIG. 24 shows the installation site 32 after removal of the conveyor device 10.
In the next working step according to FIG. 25, the support constructions 29 and the launching gantries 30 are removed at the installation site. A first top concrete layer 3 is applied onto the bottom layer 2. The weight of the top concrete layer 3 is introduced from the bottom layer 2 into the cross beams 21 and from these to the prestressed concrete beams 40. The structural steel connection of the cross beams 21 should be able to absorb any stresses arising. If the first top concrete layer 3 reaches a predetermined concrete compression strength, there is applied according to FIG. 26 onto the first top concrete layer 3 a second top concrete layer 3. After the concrete of the top concrete layers 3 has hardened, the bottom layer 2, the cross beams 21, the first top concrete layer 3 and the second top concrete layer 3 are to be considered a construction component produced in a monolithic way, in combination forming the deck slab 1.
The detail E of FIG. 23 is depicted in FIG. 27 and FIG. 28, showing the structural steel connection of the two cross beams 21. In the two cross beams 21, there are installed steel panels 42 projecting beyond the front faces of the cross beams 21. Upon lowering the bottom layer 2 and the cross beams 21, the steel panels 42 are supported on the prestressed concrete beams 40. Subsequently, there is produced by using two steel slabs 35 and screw connections 41 a flexurally rigid connection of the two cross beams 21.
An alternative embodiment for producing a flexurally rigid connection of the two cross beams 21 is shown in the FIG. 29 and the FIG. 30. There is installed in the prestressed concrete beam 40 a steel panel 42. Front faces 43 are welded to the steel panel 42 at the left and right side. At the front faces of the cross beams 21, there are attached front faces 43 made from steel, which are connected by means of starter bars not depicted in the cross beams 21. Upon lowering the bottom layer 2 having the embedded cross beams 21, there is produced a flexurally rigid connection of the cross beams 21 with the prestressed concrete beam 40 by way of the screw connections 41. Such a connection may also be advantageous if only cantilevering segments 17 are to be connected to a longitudinal bridge girder 5 having a box-section-like cross-section.
A fifth embodiment of the method according to the invention is depicted in the illustrations FIG. 31 to FIG. 37.
According to FIG. 31 at the assembly site 31 three prefabricated elements 47 are laid on mounting beams 20. Each prefabricated element 47 is composed of three prefabricated slabs 50 and one cross beam 21 configured as prefabricated beam 27 and connecting the three prefabricated slabs 50 one to another. The bottom layer 2 is formed in this mounting state of three segments 17.
In the next working step, there is laid a reinforcement onto the bottom layer 2 and there is produced a first top concrete layer on the prefabricated slabs 50. The three segments 17 of the bottom layer 2 are joined to one segment 17 by the first top concrete layer 3. FIG. 32 shows the state at the assembly site 31 after the first top concrete layer 3 has been produced.
FIG. 33 shows the transport of the bottom layer 2 having cross beams 21 and a first top concrete layer 3 for a construction section of the deck slab 1 from the assembly site 31 to the installation site 31. The transport is carried out using a conveyor device 10. The conveyor device is composed of a front part 44 and a rear part 45, which are configured as frame constructions 49. The front part 44 and the rear part 45 of the conveyor device 10 are connected to one another by way of two longitudinal girders 46. The conveyor device 10 is moved in the longitudinal direction of the bridge 4 on support constructions 29, which are situated on longitudinal bridge girder 5, which is in this example composed of two steel girders 9. The weight of the bottom layer 2 having the cross beams 21 and the first top concrete layer 3 is introduced in this transport state into six tendons 11. The lower end points 13 of the tendons 11 are arranged within the cross beams 21. The upper end points 13 of the tendons 11 are attached at the top surface of hydraulic hollow piston jacks 48. During transport, the bottom layer 2 having the cross beams 21 and the first top concrete layer 3 is in a raised position to prevent any contact of the cross beams 21 with the bracing means 6, which are not depicted in FIG. 33 for reasons of clarity and mounted on the longitudinal bridge girder 5, and to make it possible to drive on construction sections already completed of the deck slab 1. FIG. 33 shows that the pistons 51 of the hollow piston jacks 48 are in an extracted position in order to be able to transport the bottom layer 2 having the cross beams 21 and the first top concrete layer in a raised position.
According to FIG. 34, the pistons 51 of the hollow piston jack 48 are retracted at the installation site 32 to be able to lower the bottom layer 20 having the cross beams 21 and the first top concrete layer 3 into the scheduled final position. Immediately following the lowering operation, the lower end points 13 of the tendons 11 may be released and the conveyor device 10 may be moved from the assembly site 32 to the installation site 31 to pick up there a further bottom layer 2 having cross beams 21 and a first top concrete layer 3 for a further construction section of the deck slab 1. At the installation site 32, immediately after the conveyor device 10 has left or at a later point of time, there may be laid the starter bars to a neighbouring construction sections and the second top concrete layer 3 may be applied. The weight of the additional reinforcement and of the second top concrete layer 3 is absorbed by the bottom layer 2, the cross beams 21 and the first top concrete layer 3. In order to reach the goal of the bottom layer 2, the cross beams 21 and the two top concrete layers 3 in the final condition of the deck slab 1 behaving like a construction section produced in one pour, it is necessary to configure the surfaces rough and to provide the necessary starter bars.
A bridge 4 comprising two abutments 33, five pillars 34 and one longitudinal bridge girder 5 is depicted in the illustrations FIG. 35 to FIG. 37. As shown in FIG. 35, the support constructions 29 are mounted on the longitudinal bridge girder 5 and the assembly site 31, which is situated on one of the two abutment 33. The conveyor device 10 is composed of a front part 44 and a rear part 45, which are connected to one another by two longitudinal girders 46. On the assembly site 31, the bottom layer 2 having the cross beams 21 and the first top concrete layer 3 is raised by extracting the pistons 51 of the six hollow piston jacks 48. The bottom layer 2 having the cross beams 21 and the first top concrete layer 3 is arranged in this condition between the front part 44 and the rear part 45 and underneath the longitudinal girders 46 of the conveyor device 10.
According to FIG. 36, the bottom layer 2 having the cross beams 21 and the first top concrete layer 3 is moved in the next method step from the assembly site 31 to the installation site 32. At the installation site 32, the bottom layer 2 having the cross beams 21 and the first top concrete layer 3 is lowered until the cross beams 31 are supported on the top surface 18 of the longitudinal bridge girder 5. To enable the lowering operation of a bottom layer 2 composed of a segment 17 and having cross beams 21 and a first top concrete layer 3 at the installation site 32, there must not be arranged any construction elements for connecting the front part 44 and the rear part 45 of the conveyor device 10 underneath the segment 17.
Immediately following the lowering operation, the lower end points 13 of the tendons 11 may be released from the cross beams 21 and the conveyor device 10 may be moved from the installations site 32 back to the assembly site 31 to pick up there a further bottom layer 2 having cross beams 32 and a first top concrete layer 3 for a further construction section of the deck slab 1.
In this embodiment example it is particularly advantageous that at the installation site 32 it is not necessary to wait for the top concrete layer 3 to harden. The conveyor device 10 may be moved away from the installation site 32 immediately after the bottom layer 2 having the cross beams 21 and the first top concrete layer 3 has been lowered. In this way it is possible to produce one construction section of the deck slab 1 per day. Producing the second top concrete layer 3 is independent of the bottom layer 2 having cross beams 31 and first top concrete layer being laid and may be realized at any point of time.
According to FIG. 37, after the production of the deck slab 1, all support constructions 29 are removed by cutting off the steel profiles in the vicinity of the surface of the top concrete layer 3. Subsequently, the bridge 4 is completed in the usual manner by applying a sealing onto the surface of the top concrete layer 3 and subsequently applying a deck cover.
A sixth embodiment of the method according to the invention is depicted in the illustrations FIG. 38 and FIG. 39.
The bottom layer 2 having cross beams 21 is produced at the assembly site 31 on a framework 23. The bottom layer 2 having cross beams 21 is composed in this embodiment example of one segment 17, as the three cross beams 21 extend across the entire width of the deck slab 1 to be produced and, in this way, a continuous construction component is being developed. FIG. 38 shows the transport of the bottom layer 2 having cross beams 21 for a construction section of the deck slab 1 from the assembly site 31 to the installation site 32. In this embodiment example raising the bottom layer 2 having the cross beams 21 is realized by extracting the pistons 51 of the hollow piston jacks 48, which are arranged between the longitudinal girders 46 and the front part 44 or the rear part 45, respectively, of the conveyor device 10.
According to FIG. 39, the pistons 51 of the hollow piston jacks 48 are retracted at the installation site to be able to lower the bottom layer 2 having the cross beams 21 into the scheduled final position. Immediately after depositing the bottom layer 2 having the cross beams 31 at the installation site 32, the lower end points 13 or the upper end points 12 of the tendons 11 may be released and the conveyor device 10 may be moved to the assembly site to pick up a further bottom layer 2 having cross beams 21 for a further construction section of the deck slab 1.
LIST OF REFERENCES
1 deck slab
2 bottom layer
3 top concrete layer
4 bridge
5 longitudinal bridge girder
6 bracing means
7 lane
8 wheel
9 steel girder
10 conveyor device
11 tendon
12 upper end point of a tendon
13 lower end point of a tendon
14 anchor
15 device
16 recess
17 segment of a bottom layer
18 top surface of a longitudinal bridge girder
19 bottom surface of a bottom layer
20 mounting girder
21 cross beam
22 strip
23 formwork
24 gap
25 bottom surface of a bottom layer
26 ribbed base plate
27 prefabricated beam
28 longitudinal edge beam
29 support construction
30 launching gantry
31 assembly site
32 installation site
33 abutment
34 pillar
35 steel slab
36 threaded nut
37 sleeve tube
38 cladding tube
39 bracing wire
40 prestressed concrete beam
41 screw connection
42 steel panel
43 front slab
44 front part of a conveyor device
45 rear part of a conveyor device
46 longitudinal girder of a conveyor device
47 prefabricated element
48 hollow piston jack
49 frame construction
50 prefabricated slab
51 piston
Patent Application
20230160160
