Concrete floor slab and method for forming concrete floor slab

Abstract

To provide a concrete floor slab that can be repaired by removing a precast slab only to the extent of damage and replacing a remaining part with a new precast slab while maintaining prestress.SOLUTION: A plurality of standard parts 31 each consisting of a prescribed number of standard precast slabs 11, and a connecting precast slab 12 or a connecting part 32 made of cast-in-place concrete are alternately provided. A tension material that introduces prestress is arranged in the axial direction of a bridge girder 1 across each standard part and the connecting parts adjacent to both sides thereof. The tension material is obtained by connecting a standard part tension material 21 arranged in the standard parts and a continuous part tension material 22 arranged in the connecting part by a connector 23. Two connecting part tension materials are arranged within the connecting part so that the axial ranges of the bridge girder overlap. A joint part fixing tool 24 capable of fixing a tension force to the standard part is then arranged in the vicinity of a joint part between the standard part and the connecting part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a concrete deck formed by arranging concrete precast slabs on a bridge girder, and more particularly to a concrete deck that allows some precast slabs to be easily replaced and repaired, and a method for forming a concrete deck. [Background technology]

[0002] For the concrete deck formed on the bridge girder, multiple precast plates are arranged in the axial direction of the bridge girder and connected together. Prestress is then introduced in the axial direction of the bridge girder to firmly unite the precast plates, as disclosed in Patent Document 1, for example.

[0003] Concrete decks formed in this way may become damaged due to aging and other factors. When a concrete deck becomes damaged, it becomes necessary to restore its functionality through repairs, and the damaged precast deck is replaced. However, in concrete decks where prestress is introduced in the axial direction of the bridge girder, continuous tendons are embedded across multiple precast decks. If the tendons are cut to remove some of the precast decks, there is a risk that the prestress will be released over a wide area. For this reason, when trying to replace a precast deck, a wide area must be replaced at the same time, which requires a lot of work and costs.

[0004] In view of these circumstances, Patent Document 2 discloses a concrete floor slab that is designed to have part of the precast slab replaced later. This concrete deck is made of multiple precast concrete panels arranged on a girder, and a tension anchoring panel group consisting of three panels is provided for each span of the bridge. The tension anchoring panel group is composed of two anchoring panels and one connecting panel arranged between them, and multiple normal panels are arranged between the tension anchoring panel groups. The tendons are connected by connectors and tension is introduced sequentially, but continuous prestress is introduced to a series of normal panels and two adjacent anchoring panels on both sides, and anchoring devices are attached to both ends of these. Therefore, even if the connecting panel is removed, the prestress of the anchoring panel and the normal panel on both sides is maintained. This makes it possible to remove the connecting panel of the two tension anchoring panel groups, remove the series of normal panels between them and the adjacent anchoring panels, and replace them. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 07-102529 [Patent Document 2] Japanese Patent Application Publication No. 07-268808 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned conventional techniques have the following problems that need to be solved. When a part of a panel made of precast concrete is damaged and needs to be replaced, at least two anchoring panels, two connecting panels, and a series of normal panels between the two anchoring panels must be replaced. This does not fully address the demand to minimize the number of panels to be replaced and reduce repair costs. In addition, when installing the concrete slab, it is necessary to provide the anchoring panels with ducts for placing cap cables and anchoring blocks for fixing the tension members placed in the ducts. The cap cables are used to introduce prestress to the tension anchoring panels after the panels are replaced, and therefore ducts and anchoring blocks are provided that are not used when installing the concrete slab.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a concrete deck that can be easily repaired by limiting repair to only those areas that have been damaged and require replacement, and to provide a method for forming such a concrete deck. [Means for solving the problem]

[0008] In order to solve the above problems, the invention described in claim 1 is a concrete floor slab in which a plurality of precast slabs are arranged on a bridge girder and prestress is introduced in the axial direction of the bridge girder to join the plurality of precast slabs, the concrete slab comprising a plurality of standard sections each made of a predetermined number of standard precast slabs and a connecting section made of connected precast slabs or concrete poured on site. In the axial direction of the bridge girder are provided alternately in succession, Each standard part is arranged A tendon that introduces prestress in the axial direction of the bridge girder, Each Adjacent on both sides of the standard The above A standard portion is disposed across the connecting portion, and a standard portion is disposed in two adjacent standard portions on either side of the connecting portion. Each of the tendons is between two of the standard sections. In the connecting section, the axial direction of the bridge girder arrangement The ranges are arranged so that they overlap, The above The tension material has both ends, Adjacent to both sides of each of the standard portionsA concrete floor slab is provided which is fixed to the connecting portion by a fixing device, and in which a joint fixing device capable of fixing tension to the standard portion is disposed near the joint between the standard portion and the connecting portion.

[0009] In this concrete slab, even if the connecting parts between the multiple standard parts are removed, the tension of the tendons is fixed to the standard parts by the joint fixing devices. Therefore, when damage occurs to the precast slab, even if the standard part including the damaged part and the connecting parts adjacent to both sides are removed, the remaining area of ​​the concrete slab can maintain a prestressed state. Then, it is possible to repair the damaged concrete slab by placing a new standard precast slab after the removed standard part and forming a connecting part by placing a new connecting precast slab or by casting newly in place concrete.

[0010] The invention of claim 2 is a concrete floor slab described in claim 1, wherein the tension member comprises a standard tension member arranged in the standard section, and a connection section tension member connected to the standard tension member by a connector and arranged in the connection section, the standard section tension member is fixed to the standard section by the joint section fixing device with a tensioning force being introduced, and the connection section tension member is fixed to the connection section by the fixing device with a tensioning force being introduced.

[0011] This concrete deck allows for efficient repairs by partially replacing the precast slab, and when forming the concrete deck, standard sections or connecting sections can be constructed simultaneously over a wide area, allowing for efficient construction when forming a concrete deck over a long distance.

[0012] The invention of claim 3 is a concrete floor slab described in claim 1, wherein the tension member is continuous from the standard section to the connecting section, and both ends are fixed to the connecting section by the fixing device with tension applied, and the joint fixing device is attached near the joint between the standard section and the connecting section so as to fix the tension of the tension member to the standard section.

[0013] This concrete deck allows efficient repairs by partially replacing the precast deck. In addition, the tension rods are continuous from the standard section to the joint section, which reduces the number of joints of the tension rods when forming the concrete deck, and also reduces the number of tensioning operations, making it possible to reduce construction costs.

[0014] The invention according to claim 4 provides a standard section in which a plurality of standard precast slabs are arranged in succession on a bridge girder, In the axial direction of the bridge girder forming a plurality of standard sections at intervals; and introducing prestress in the axial direction of the bridge girder into each standard section by tensioning the standard section tendons arranged in each standard section; Both ends of the standard section tendon are fixed to the standard section by joint fixing devices; A connecting precast plate is disposed between the standard portions, and adjacent to both sides of the connecting precast plate The above Connecting a connecting section tendon to each of the standard section tendons arranged in the standard section; A tension member is connected between the two standard sections and to each of the two standard section tendons. Both connecting tendons are in the axial direction of the bridge girder. The placement range in Arrange them so that they overlap at least partially, The connected precast panels and Adjacent The above Fill the gap between the standard section and the concrete with mortar or concrete. The linked precast panels The standard part and Forming a jointed joint The present invention provides a method for forming a concrete floor slab by introducing tension into the connecting portion tendons connected to the standard portion tendons so that the tendons are fixed to the connecting portion, and the connecting portion is joined to both of the standard portions adjacent to each other on both sides so as to become one body.

[0015] This method for forming a concrete slab makes it possible to form a concrete slab that can be repaired efficiently by replacing a portion of the precast slab. When constructing a new concrete slab, multiple standard sections can be formed in parallel, and multiple connecting sections between these standard sections can be formed in parallel, making it possible to carry out efficient work.

[0016] The invention according to claim 5 comprises: arranging a plurality of standard precast slabs constituting a first standard section in succession on a bridge girder, and arranging a first connecting precast slab adjacent to the end; arranging a first tendon continuing from the first standard section to the first connecting precast slab, and introducing tension to fix both ends; at the joint between the first standard section and the first connecting precast slab, a joint fixing device is attached to the continuous portion of the first tendon to which tension has already been introduced so as to be fixed to the standard precast slab side; arranging a plurality of standard precast slabs constituting a second standard section on the side of the first connecting precast slab opposite to the side adjacent to the first standard section, and arranging a second connecting precast slab at the end; arranging a second tendon such that the axial arrangement range of the first tendon and the bridge girder overlap within the first connecting precast slab and continuing to the second connecting precast slab; The present invention provides a method for forming a concrete floor slab, in which tension is introduced into a second tension member to fix both ends to a first connecting precast plate and a second connecting precast plate, and at the joint between the standard precast plate constituting the second standard section and the first connecting precast plate and the second connecting precast plate, a joint fixing device is attached to the second tension member so that it can be fixed to the standard precast plate.

[0017] This method of forming a concrete deck allows the standard section and the connecting section to be formed sequentially in the axial direction of the bridge girder, and prestress can be efficiently introduced to both the standard section and the connecting section by means of the tendons that are continuous with the standard section and the connecting section. In addition, because joint fasteners are attached to the tension members at the joints between the connecting parts and the standard parts, if damage occurs to the precast slab, the prestress in the remaining standard part is maintained even if the precast slab is removed from the limited area including the damaged area. This makes it possible to create a concrete slab that can be efficiently replaced in the limited area and repaired at low cost.

[0018] The invention according to claim 6 provides a standard section in which a plurality of standard precast slabs are arranged in succession on a bridge girder, In the axial direction of the bridge girder forming a plurality of standard sections at intervals; and introducing prestress in the axial direction of the bridge girder into each standard section by tensioning the standard section tendons arranged in each standard section; The standard section tendon is fixed to the standard section by a joint fixing device, Adjacent Two Between the standard parts, the Standard section Connecting each of the tendons to a connecting tendon; Both of the connecting portion tendons are The bridge girder is arranged so that the axial direction of the bridge girder is overlapped, and concrete is poured between the standard parts so that the standard parts are in close contact with one of the standard parts and separated from the other to form a connecting part, and the standard parts in close contact with the connecting part are arranged so that the concrete is poured between the standard parts so that the concrete is poured between the standard parts and the connecting part. The above The present invention provides a method for forming a concrete floor slab, comprising the steps of: introducing tension into the connecting section tension member connected to the standard section tension member so as to fix it to the connecting section, and joining the connecting section to one of the adjacent standard sections so as to become one unit; then filling the space between the other of the adjacent standard sections and the connecting section with mortar or concrete; introducing tension into the other of the connecting section tension member so as to fix it to the connecting section, and joining the connecting section to the other of the adjacent standard sections so as to become one unit.

[0019] In the concrete deck formed in this way, standard section tendons are fixed to each standard section, and when damage occurs to the joints formed with the precast slabs or cast-in-place concrete, the precast slabs can be replaced or the concrete can be replaced in a limited area including the damaged area, allowing for efficient repairs. In addition, when tension is introduced into the connection tendons arranged in the connection, one of the connection tendons is tensioned and joined to one of the standard sections, while it is separated from the other standard section. This allows prestress to be effectively introduced into the connection by one of the connection tendons. Then, when one of the connection tendons is tensioned and then joined to the other standard section and the other connection tendon is tensioned, the amount of prestress introduced is limited by the restraining force of the already joined standard section, but the prestress introduced by both connection tendons can be more effectively introduced than when both connection tendons are tensioned after joining to both adjacent standard sections. Effect of the Invention

[0020] As described above, in the concrete slab of the present invention, it is possible to remove only the damaged area and repair the remaining part while maintaining the prestress. In addition, in the method of forming a concrete slab of the present invention, it is possible to provide a concrete slab that can be repaired by removing a part of it while maintaining the prestress of the remaining part. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic perspective view showing a configuration of a bridge having a concrete deck of the present invention. [Diagram 2] 1 is a schematic cross-sectional view in the axial direction of a bridge having a concrete deck according to one embodiment of the present invention, and a schematic cross-sectional view showing an enlarged portion of the concrete deck of the bridge. [Diagram 3] 3 is a schematic cross-sectional view showing an enlarged view of the boundary between a standard portion and a joint portion of the concrete floor slab shown in FIG. 2. [Figure 4] FIG. 4 is a schematic diagram showing a process for forming the concrete deck shown in FIG. 2 and FIG. 3. [Diagram 5] FIG. 4 is a schematic diagram showing a process for forming the concrete deck shown in FIG. 2 and FIG. 3. [Figure 6]1 is a schematic cross-sectional view in the axial direction of a bridge having a concrete deck according to another embodiment of the present invention, and a schematic cross-sectional view showing an enlarged portion of the concrete deck of this bridge. [Figure 7] 7 is a schematic cross-sectional view showing an enlarged view of the boundary between a standard portion and a joint portion of the concrete floor slab shown in FIG. 6. [Figure 8] FIG. 8 is a schematic diagram showing a process for forming the concrete deck shown in FIGS. 6 and 7. [Figure 9] FIG. 8 is a schematic diagram showing a process for forming the concrete deck shown in FIGS. 6 and 7. [Figure 10] FIG. 8 is a schematic diagram showing a process for forming the concrete deck shown in FIGS. 6 and 7. [Figure 11] 1 is a schematic cross-sectional view in the axial direction of a bridge having a concrete deck according to another embodiment of the present invention, and a schematic cross-sectional view showing an enlarged portion of the concrete deck of this bridge. [Figure 12] 12A and 12B are schematic cross-sectional views showing an example in which the joint portion of the concrete floor slab shown in FIG. 11 is formed by another process, and schematic cross-sectional views showing the process of forming this joint portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic perspective view showing the configuration of a bridge having a concrete deck of the present invention, and Fig. 2 is a schematic cross-sectional view in the axial direction of a bridge having a concrete deck according to one embodiment of the present invention, and a schematic cross-sectional view showing an enlarged portion of the concrete deck of the bridge. This bridge is used as a road bridge, and consists of concrete precast slabs 10 arranged on bridge girders 1 supported by piers 2 or abutments 5, which are then connected and fixed to the bridge girders 1 to form the concrete deck 3. Three types of precast slabs are used: a standard precast slab 11 that constitutes the standard part of the concrete deck, a connecting precast slab 12 that constitutes the connecting part, and an end precast slab 13 that is placed at the end of the bridge girders, and each precast slab is provided with multiple ducts 14 in the axial direction of the bridge girders 1. Prestress in the axial direction of the bridge girders 1 is introduced into the concrete deck 3 by tensioning and fixing the tendons inserted through these ducts.

[0023] The bridge girder 1 is made up of multiple steel girders 81 arranged in parallel and connected by cross beams 82, and each steel girder 81 has an upper flange 83, a lower flange 84, and a web 85 that connects them vertically. A slip prevention member 86 for fixing the precast slab is provided on the upper surface of the upper flange.

[0024] The precast slabs 10 are formed in advance in a factory or production yard by pouring concrete, and have a predetermined dimension in the axial direction of the bridge girder 1. The dimension perpendicular to the axis of the bridge girder corresponds to the width of the road. These precast slabs 10 may have prestress introduced in the direction perpendicular to the axis of the bridge girder 1, and the prestress may be introduced by either the pretensioning method or the posttensioning method.

[0025] These precast slabs 10 are arranged on the bridge girder in the axial direction of the bridge girder, connected together, and fixed to the steel girder 4 with anti-slip members 86. Adjacent precast slabs may be connected with a synthetic resin adhesive or the like, or the precast slabs may be arranged with gaps of about 10 mm to 40 mm between them and connected by filling the gaps with non-shrink mortar.

[0026] As shown in Fig. 2(a), the concrete deck is formed by alternating standard sections 31 formed by continuously arranging a plurality of standard precast slabs 11 and connecting sections 32 consisting of one connected precast slab in the axial direction of the bridge. In this embodiment, three standard precast slabs 11 are arranged in one standard section, but the number of arrangements can be set appropriately in advance. Note that end precast slabs 13 are arranged at the ends of the bridge girder 1 instead of the standard precast slabs.

[0027] The standard precast slab 11 is provided with a plurality of ducts 14 through which tendons are inserted in the axial direction of the bridge girder. These ducts 14 are formed in a straight line substantially parallel to the upper and lower surfaces at the approximate center of the thickness of the standard precast slab. On the other hand, the connected precast slab 12 has a thickened portion for enabling tensioning and fixing of the tendons. Also, a notch 12a is provided at both ends joined to the standard precast slab 11, and the tendons are exposed within the notch. The duct 15 formed in the connected precast slab 12 has one end opening within the notch 12a, and the other end opening below the adjacent standard precast slab 11 on the opposite side. The opening within the notch 12a is provided at a position facing the duct 14 of the adjacent standard precast slab 11. The ducts 15 are formed so as to cross each other from the notches 12a provided at both ends toward the opposite sides. An end precast slab 13 placed at the end of the bridge girder has a linear duct formed therein so as to be continuous with the standard precast slab 11. In addition, these precast panels have the necessary reinforcing bars arranged appropriately, but these are not shown in Figures 2, 3, etc.

[0028] The tendons for introducing prestress into the precast slabs 10 arranged as described above are a series of tendons that penetrate the standard section and the connecting sections on both sides of the standard section. Each tendon is made up of a standard section tendon 21 arranged in the standard section and a connecting section tendon 22 arranged in the connecting sections on both sides, which are connected by a connector 23. The standard section tendon 21 has both ends fixed to the standard section precast slabs by joint fixing devices 24 with tension applied. The connecting section tendon 22 has one end connected by a connector 23 to the end of the standard section tendon 21 fixed to the standard precast slab 11, and is fixed to the connecting precast slabs 12 by a fixing device 25 with tension applied from the other end. At the end of the bridge girder 1, an end precast plate 13 is used instead of the standard precast plate, and the standard section tendon 21 is fixed to the end precast plate 13 by a joint fixing device 24.

[0029] The standard section tendons 21 and the connecting section tendons 22 are made of steel strands, and as shown in Fig. 3, the joint section fixing device 24 uses a wedge. This joint section fixing device 24 has a bearing plate 24a arranged in close contact with the standard precast slab 11, a wedge holding member 24b which is a cylindrical member whose inner diameter gradually expands, and a wedge 24c which is pressed between the standard section tendons 21 inserted into the hollow hole of the wedge holding member 24b and the inner peripheral surface of the wedge holding member 24b. This joint section fixing device 24 is used to fix the standard section tendons 21 at both ends of the standard section, and is also used to fix them to the end precast slabs 13.

[0030] On the other hand, the connector 23 includes a wedge holding member 23a having a hollow hole through which the connecting portion tendon 22 is inserted, a wedge 23b pressed between the connecting portion tendon 22 and the inner peripheral surface of the wedge holding member 23a, and a connecting member 23c connecting the wedge holding member 23a and a wedge holding member 24b for fixing the standard portion tendon 21, as shown in Fig. 3. The connecting member 23c is a substantially cylindrical member having a flange portion 23d that protrudes from one end so as to narrow the inner diameter, and a female thread portion formed on the inner peripheral surface near the other end. The female thread portion of the connecting member 23c is screwed together with a male thread formed on the outer peripheral surface of the wedge holding member 24b for fixing the standard portion tendon 21. The wedge retaining member 23a attached to the connecting portion tension member 22 is accommodated in the hollow hole and abutted against the flange portion 23d to engage with it, thereby connecting the standard portion tension member 21 and the connecting portion tension member 22.

[0031] The fixing device 25 for fixing the connecting portion tension member 22 has a support plate 25a, a wedge holding member 25b, and a wedge 25, similar to the fixing device 23 for fixing the standard portion tension member 21, but this fixing device 25 has a male thread formed on the outer peripheral surface of the wedge holding member 25b, and is provided with a nut 25d that is twisted onto the outer peripheral surface of the wedge holding member 25b. This nut 25d is capable of gripping the wedge holding member 25b and tightening the connecting portion tension member 22 to the support plate 25a in a tensioned state.

[0032] Such a concrete deck can be formed by the following steps. As shown in Fig. 4(a), standard precast slabs 11 are arranged in predetermined positions on bridge girder 1. That is, a predetermined number of standard precast slabs 11 are arranged in an area that is to be left open to form connecting portions 32 and used as standard portions 31. Mortar is then filled between adjacent standard precast slabs 11 in one standard portion, and standard portion tendons 21 are inserted into ducts 14 formed in the standard precast slabs 11. These standard portion tendons 21 are tensioned and fixed at both ends of the standard portion by joint portion fixing devices 24.

[0033] Thereafter, as shown in Fig. 4(b), the connected precast slabs 12 are placed between the standard sections 31 in which prestress has been introduced by the tension of the standard section tendons 21. Then, as shown in Fig. 5(a), the connection section tendons 22 are inserted into the ducts 15 of the connected precast slabs 12 that open on the lower side of the standard precast slabs 11. The ends of the connection section tendons 22 are connected by connectors 23 to the standard section tendons 21 fixed to the standard section precast slabs in the notches 12a formed on the ends of the connected precast slabs 12. Then, the notches 12a formed in the connected precast slabs 12 are filled with concrete, and after it hardens, the connection section tendons 22 are tensioned and fixed on the lower side of the standard precast slabs 11 as shown in Fig. 5(b).

[0034] In such a concrete slab 3, when damage occurs only in the connected precast slabs 12, only the connected precast slabs 12 are removed, and when damage occurs in the standard portion 31, the standard precast slab 11 of the standard portion 31 and the connected precast slabs 12 on both sides are removed and replaced, allowing repairs to be made. At this time, even if the connecting portion tendons 22 connected by the connectors 23 are removed, the standard portion tendons 21 are fixed to the standard precast slab 11 by the joint fixing devices 24, and the prestress of the remaining standard portion 31 is maintained. Then, after new standard precast slabs and connected precast slabs are placed, prestress can be introduced in the same way as when the concrete slab was formed, and the concrete slab can be repaired. Furthermore, when constructing such a new concrete floor slab 3, if the area to be newly constructed is long, the formation of the standard sections and the formation of the connecting sections can each be carried out simultaneously over a wide area, enabling efficient construction.

[0035] FIG. 6 is a schematic cross-sectional view in the axial direction of a bridge having a concrete deck 4 according to another embodiment of the present invention, and a schematic cross-sectional view showing an enlarged portion of the concrete deck of this bridge. 2 and 3, this concrete slab 4 has standard sections 41 formed by arranging a plurality of standard precast slabs 51 and connecting sections 42 formed by one connected precast slab 52, which are alternately arranged in the axial direction of the bridge. Similarly, for the tendons 54 that introduce prestress into the precast slabs arranged as described above, a series of tendons 54 are used for each standard section 41 so as to penetrate the standard section 41 and the connecting sections 42 on both sides of the standard section 41. As shown in FIG. 6(b), these tendons 54a are arranged so that the tendons 54b arranged in the adjacent standard sections overlap with the tendons 54b arranged in the connected precast slab 52 in the axial direction of the bridge girder.

[0036] However, in this concrete slab, unlike the concrete slab 3 shown in Figures 2 and 3, a series of tension members 54 are continuous from one connecting part 42-1 to the other connecting part 42-2 without being connected. Both ends of this tension member 54 are fixed to the connected precast slabs 52-1, 52-2 by fixing devices 55 while tension is being introduced. As shown in Figures 6(b) and 7, an intermediate fixing device 56 is attached to the joint between the connected precast slabs 52 and the standard precast slab 51 as a joint fixing device so that the tension of the tension member 54 can be transmitted to the standard precast slab 51. However, the tension of the tension member 54 is not transmitted to the standard precast slab 51 through this intermediate fixing device 56, but the tension member 54 is continuously introduced with approximately the same tension before and after the intermediate fixing device 56. When the fixing of the end of the tension member 54 is released, the tension of the tension member 54 can be transmitted to the standard precast slab 51 and fixed. The intermediate fixing device 56 is attached within a notch 52a formed in the interconnecting precast slab 52, and this notch 52a is filled with concrete after tension is introduced into the tendon 54 and the intermediate fixing device 56 is attached to the tendon.

[0037] In this concrete slab, steel strands are also used for the tendons 54, and as shown in Fig. 7, the fixing device 55 has a support plate 55a, a cylindrical wedge holding member 55b through which the tendons 54 are inserted, a wedge 55c that is pressed between the wedge holding member 55b and the tendons 54, and a nut 55d that is twisted onto the outer circumferential surface of the wedge holding member. The intermediate fixing device 56 has a support plate 56a, a wedge holding member 56b, and a wedge 55c.

[0038] Such a concrete deck 4 can be formed, for example, as follows. As shown in Fig. 8(a), an end precast slab 53, a standard precast slab 51, and a connecting precast slab 52-1 are arranged starting from the end of the bridge girder 1. Then, as shown in Fig. 8(b) and Fig. 10(a), a tendon 54-1 is inserted through the ducts formed in these precast slabs. At this time, a support plate 56a of the intermediate fixing device is fixed to the surface of the standard precast slab 51 that is joined to the connecting precast slab 52 so that it matches the position of the duct. It is also desirable to temporarily fix the wedge retaining member 56b to the support plate 56a with an adhesive or the like.

[0039] Tension is applied to the inserted tendon 54-1 by a jack or the like, and both ends are fixed at the positions where the duct of the connected precast slab 52-1 and the duct of the end precast slab 53 open. Thereafter, by operating within the notch 52a provided in the connected precast slab 52 at the joint between the connected precast slab 52-1 and the standard precast slab 51, the temporary fixation of the wedge retaining member 56b adhered to the support plate 56a is released, and a wedge 56c is pushed in between the wedge retaining member 56b and the tendon 54-1. It is preferable to push the wedge 56c in strongly using a jack or the like.

[0040] Next, as shown in Fig. 9(a), a plurality of standard precast slabs 51 constituting the second standard part 41-2 are arranged at a position adjacent to the connected precast slab 52-1 on the opposite side of the standard part 41-1 to which tension is introduced, and a second connected precast slab 52-2 is arranged ahead of them. Then, as shown in Fig. 9(b) and Fig. 10(b), a tension member 54-2 is inserted into the duct so as to penetrate the standard precast slab 51 constituting the second standard part 41-2 and the two connected precast slabs 52-1, 52-2 adjacent to each other on both sides. At the joint between the connected precast slabs 52 and the standard precast slabs 51, the tension member 54-2 is inserted into the bearing plate 56a and the wedge retaining member 56b in the same manner as when the tension member 54-1 was inserted into the first standard part 41-1. Tension is applied to the tendon 54-2, and both ends are fixed to the connecting precast slabs 52-1 and 52-2 on both sides of the second standard section 41-2. Then, a wedge 56c is pressed between the wedge retaining member 56b and the tendon 54-2 at the joint between the connecting precast slabs 52-1 and 52-2 and the second standard section 41-2.

[0041] In this manner, the precast plates are sequentially connected by repeating the process of arranging the multiple standard precast plates 51 that form the standard portion, arranging the connected precast plates 52, inserting the tendons 54, tensioning the tendons 54, and attaching the intermediate fasteners 56. In addition, concrete is filled into the notches 52a provided in the connected precast plates 52 at the joints between the standard precast plates 51 and the connected precast plates 52. Through these steps, the concrete deck 4 can be formed.

[0042] When damage occurs in a portion of such a concrete slab 4 and it becomes necessary to replace the precast slab for repair, only the damaged connected precast slab 52, or the standard precast slab 51 of the damaged standard section 41 and the connected precast slabs 52 on both sides of it, are removed. Then, even if the tension members 54 arranged in the portion to be removed are cut, the intermediate fixing devices 56 arranged in the joints between the standard section to be left and the connecting section to be removed transmit the tension to the standard precast slab 51, and the tension members 54 are fixed in place. Therefore, it becomes possible to replace the precast slabs in the damaged portions and repair the portion of the concrete slab 4 to be left while maintaining the prestress.

[0043] FIG. 11 is a schematic cross-sectional view in the axial direction of a bridge having a concrete deck according to another embodiment of the present invention, and a schematic cross-sectional view showing an enlarged portion of the concrete deck of this bridge. 2 and 3, this concrete slab 6 has a standard section 61 formed by continuously arranging multiple standard precast slabs 71, and connecting sections 62 formed between the multiple standard sections 61, but in this concrete slab 6, the connecting sections 62 are formed from concrete poured on-site. The concrete of the connecting sections 62 is poured so as to be in close contact with the standard sections 61 on both sides, as shown in Figure 11(b).

[0044] The tendons that introduce prestress into this concrete deck 6 are a series of tendons that penetrate each standard section 61 and the connecting sections 62 on both sides of it, similar to the concrete deck 3 shown in Figures 2 and 3. These tendons are arranged so that the range in the axial direction of the bridge girder overlaps with the tendons arranged in adjacent standard sections within the connecting sections 62.

[0045] The tension members are made up of standard section tension members 74 and connecting section tension members 75, and both ends of the standard section tension members 74 are fixed to the standard precast slab 71 constituting the standard section 61 by joint section fixing devices as shown in Figure 11 (b), and connecting section tension members 75 are connected to the standard section tension members 74 by connectors 76. The connecting section tension members 75 are tensioned below the thickened section provided in the connecting section 62, and are fixed by fixing devices 77.

[0046] In this type of concrete floor slab 6, the standard precast slabs 71 of the standard sections 61 are arranged, and the standard section tendons 74 are arranged, tensioned, and fixed to introduce prestress into the standard sections 61. Thereafter, formwork is installed in the area that will become the connecting sections 62, and connecting section tendons 75 are arranged and connected to the already fixed standard section tendons 74 by connectors 76. Then, concrete is poured for the connecting sections 62 so as to embed the connecting section tendons 75 inserted into the sheaths. After this concrete has hardened, the connecting section tendons 75 are tensioned and fixed, allowing prestress to be introduced into the connecting sections 62 as well.

[0047] In addition, the concrete 72 of the connecting portion 62 may be poured so as to be in close contact with one of the adjacent standard portions 61-1 as shown in Figures 12(a) and 12(b), and a gap 79 may be formed with the other standard portion 61-2, and this gap 79 may later be filled with concrete 78 or mortar. When pouring the concrete 72 in the connecting portion 62 in this manner, the connecting portion tendon 75 is tensioned as follows. After the concrete 72 of the connecting part 62 is poured and hardened, tension is applied to the connecting part tendon 75-1 connected to the standard part tendon 74 arranged in the standard part 61-1 on the side where the concrete 72 of the connecting part 62 is in close contact, as shown in Figure 12(b), and the concrete 72 of the connecting part 62 is fixed. Then, concrete 78 or mortar is filled into the gap 79 formed between the other standard part 61-2 and the concrete 72 of the connecting part 62, so that the concrete 72 of the connecting part 62 and the other standard part 61-2 are made to be integrally continuous. Then, after the filled concrete 78 or mortar is hardened, the other connecting part tendon 75-2 is tensioned and fixed, as shown in Figure 12(c).

[0048] Pouring concrete 72 in connecting portion 62 and tensioning connecting portion tendon 75 in this way makes it possible to reduce the difficulty in introducing prestress into connecting portion 62 due to the constraint of previously formed standard portion 61-1. In particular, when repairs to this concrete slab 6 become necessary and connecting portion 62 is removed, pouring concrete for a new connecting portion and tensioning the tendon placed in this new connecting portion in the above-mentioned procedure makes it possible to introduce prestress effectively.

[0049] The concrete slab and the method for forming a concrete slab described above are embodiments of the present invention, and the concrete slab and the method for forming a concrete slab according to the present invention can be implemented by modifying the form as appropriate within the scope of the present invention. [Explanation of symbols]

[0050] 1: Bridge girder, 2: Bridge pier, 3: Concrete slab, 4: Concrete slab, 5: Abutment, 6: Concrete slab, 10: Precast plate, 11: Standard precast plate, 12: Connected precast plate, 12a: Notch in connected precast plate, 13: End precast plate, 14: Duct in standard precast plate, 15: Duct in connected precast plate, 21: standard section tension member, 22: connection section tension member, 23: connector, 23a: wedge retaining member, 23b: wedge, 23c: connection member, 23d: flange portion of connection member, 24: joint section fixing device, 24a: support plate, 24b: wedge retaining member, 24c: wedge, 25: fixing device, 25a: support plate, 25b: wedge retaining member, 25c: wedge, 25d: nut, 31: Standard part of concrete floor slab, 32: Joint part of concrete floor slab, 41: Standard part of concrete floor slab, 42: Connection part of concrete floor slab, 51: standard precast plate, 52: connected precast plate, 52a: notch provided in connected precast plate, 53: end precast plate, 54: tension member, 55: fastener, 55a: bearing plate, 55b: wedge retainer, 55c: wedge, 55d: nut, 56: intermediate fastener, 57: concrete filled in the notch, 61: Standard part of concrete floor slab, 62: Joint part of concrete floor slab, 71: Standard precast slab, 72: Concrete in connecting section, 74: Standard tension member, 75: Connection tension member, 76: Connector, 77: Fixture, 78: Concrete to fill gap, 79: Gap between concrete in connecting section and standard section, 81: Steel girder, 82: Cross girder, 83: Upper flange, 84: Lower flange, 85: Web, 86: Slip-stop member

Claims

1. A concrete deck in which a plurality of precast slabs are arranged on a bridge girder and a plurality of the precast slabs are joined by introducing prestress in the axial direction of the bridge girder, A plurality of standard sections, each of which is made of a predetermined number of standard precast slabs, and connecting sections formed of connecting precast slabs or concrete poured on site are provided alternately in a continuous manner in the axial direction of the bridge girder, Tendons that are arranged for each standard section and introduce prestress in the axial direction of the bridge girder are arranged across the adjacent connecting sections on both sides of each standard section, The tendons arranged in the two standard parts adjacent to each other across the connecting part are arranged so that their arrangement ranges in the axial direction of the bridge girder overlap within the connecting part between the two standard parts, A concrete floor slab characterized in that both ends of each of the tension members are fixed to the connecting portions adjacent to both sides of each of the standard portions by fixing devices, and a joint fixing device capable of fixing a tension force to the standard portion is arranged near the joint between the standard portion and the connecting portion.

2. the tension member includes a standard section tension member disposed in the standard section, and a connection section tension member connected to the standard section tension member by a connector and disposed in the connection section, the standard portion tendon is fixed to the standard portion by the joint portion fixing device in a state where tension is applied thereto, The concrete floor slab according to claim 1, characterized in that the connection portion tendon is fixed to the connection portion by the fixing device with tension applied thereto.

3. the tension member is continuous from the standard portion to the connecting portion, and both ends are fixed to the connecting portion by the fixing device in a state where tension is applied; A concrete floor slab as described in claim 1, characterized in that the joint fixing device is attached near the joint between the standard portion and the connecting portion so as to fix the tension of the tension member to the standard portion.

4. A plurality of standard sections, in which a plurality of standard precast panels are arranged in succession, are formed on the bridge girder at intervals in the axial direction of the bridge girder; A prestress in the axial direction of the bridge girder is introduced to each standard section by the tension of the standard section tendons arranged for each standard section, and both ends of the standard section tendons are fixed to the standard sections by joint fixing devices, A connecting precast plate is placed between the standard parts, a connecting section tendon is connected to each of the standard section tendons arranged in the standard sections adjacent to both sides of the connected precast slab, and both of the connecting section tendons connected to the two standard section tendons between the two standard sections are arranged so that at least a part of the arrangement range in the axial direction of the bridge girder overlaps; Filling mortar or concrete between the connecting precast slab and the adjacent standard portion to form a connecting portion where the connecting precast slab is joined to the standard portion; A method for forming a concrete floor slab, characterized in that tension is introduced into the connecting section tension member connected to the standard section tension member so as to fix the connecting section to the connecting section, and the connecting section is joined to both of the adjacent standard sections on both sides so as to become one united.

5. A plurality of standard precast panels constituting a first standard section are arranged continuously on the bridge girder, and a first connecting precast panel is arranged adjacent to the end portion; A first tendon is disposed so as to extend from the first standard section to the first connected precast slab, and tension is introduced to fix both ends of the tendon; At the joint between the first standard section and the first connected precast slab, a joint fixing device is attached to the continuous portion of the first tendon to which tension has already been introduced so as to be fixed to the standard precast slab side; A plurality of standard precast panels constituting a second standard portion are arranged on the side opposite to the side adjacent to the first standard portion of the first connected precast panel, and a second connected precast panel is arranged at the end portion; A second tendon is disposed in the first connecting precast slab such that the first tendon and the axial direction of the bridge girder overlap each other within the first connecting precast slab and continue to the second connecting precast slab; A tension force is introduced into the second tendon to fix both ends to the first connected precast slab and the second connected precast slab; A method for forming a concrete floor slab, characterized in that a joint fixing device is attached to the second tension member at the joint between the standard precast plate constituting the second standard section and the first connecting precast plate and the second connecting precast plate so that it can be fixed to the standard precast plate.

6. A plurality of standard sections, in which a plurality of standard precast panels are arranged in succession, are formed on the bridge girder at intervals in the axial direction of the bridge girder; A prestress is introduced in the axial direction of the bridge girder to each standard section by tension of a standard section tendon arranged for each standard section, and the standard section tendon is fixed to the standard section by a joint fixing device; Between two adjacent standard sections, a connecting section tendon is connected to each of the standard section tendons arranged in both standard sections, and both connecting section tendons are arranged so that their arrangement ranges in the axial direction of the bridge girder overlap; A connecting portion is formed between the standard portions by pouring concrete so that the connecting portion is in close contact with one standard portion and spaced apart from the other standard portion; a tension force is introduced into the connection portion tendon connected to the standard portion tendon disposed in the standard portion in close contact with the connection portion, so that the connection portion is fixed to the connection portion, and the connection portion is joined to one of the adjacent standard portions so as to be integrated; Then, fill the gap between the other of the adjacent standard parts and the connecting part with mortar or concrete; A method for forming a concrete floor slab, characterized in that a tension force is introduced into the other of the connecting portion tendon to fix it to the connecting portion, and the connecting portion is joined to the other of the adjacent standard portion so as to become one body.

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