Joint structure of floor slub and replacement method of floor slub

Abstract

To provide a joint structure between an unremoved part of an existing floor slab and a preceding renewal part of a new floor slab, which can be used for a relatively long period of time when the new floor slab is different from the existing floor slab in thickness and / or vertical position.SOLUTION: A joint structure 10 for joining an unremoved part 12a of an existing floor slab and a preceding renewal part 13a of a new floor slab includes a precast concrete connection main part 11 disposed between the unremoved part 12a and the preceding renewal part 13a. The cross-sectional shape orthogonal to the bridge-axis direction of a first section 31a having the largest slab thickness in a concrete part 31 of the connection main part 11 includes the outer contour of end surfaces 18, 26 facing the connection main part 11 in the unremoved part 12a and the preceding renewal part 13a when viewed from the bridge-axis direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a joint structure between the unremoved portion of the existing deck and the pre-renewed portion of the new deck, which is used in replacement work for decks installed on the main girders of a road bridge, in order to put the road into service after replacing the deck in a section in the bridge axis direction, and to a deck replacement method that incorporates said joint structure. [Background technology]

[0002] Conventionally, in the case of bridge deck replacement work, traffic control is implemented at night and the road is opened during the day. For this reason, various temporary structures have been proposed to temporarily suspend construction and open the road.

[0003] For example, Patent Document 1 describes a method in which temporary covering plates are erected to cover the joints between newly installed precast deck slabs, allowing vehicles to pass through without pouring concrete into the joints.

[0004] Furthermore, Patent Document 2 describes a method in which after removing part of the existing deck, a temporary lining deck is placed on the bridge girder of the removed portion, thereby temporarily allowing vehicles to pass through. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-082622 A [Patent Document 2] JP 2022-134750 A Summary of the Invention [Problem to be solved by the invention]

[0006] If a road or railway under the jurisdiction of another organization exists below the bridge under construction, it is necessary to consult with the other organization before proceeding with the construction. If the road or railway below does not completely overlap the bridge under construction in plan view, but overlaps only partially, such as when they cross, it is possible to replace the deck slab of the part excluding the part above the road or railway first, and then replace the part above the road or railway after the consultation is completed. In such cases, or due to budgetary constraints, it is expected that the construction will be carried out by replacing a certain section of the deck in the bridge axis direction first, keeping the road in service for several months, and then replacing the remaining section of the deck.

[0007] Also, when replacing decks, due to revisions to design standards, the thickness of the new deck may be designed to be thicker than that of the existing deck so that it can withstand a greater live load than at the time of construction. Also, in order to shorten the construction period, the new deck is often constructed using precast concrete members. In this case, non-shrink mortar or the like is filled between the main girders and the precast concrete members, so the vertical position of the new deck relative to the main girders is higher than the vertical position of the existing deck relative to the main girders.

[0008] However, the above-mentioned temporary structures were intended to be removed within one or several days. If they were used for a relatively long period of time, such as several months, there was a risk that malfunctions would occur in the existing deck, the new deck and / or the temporary structure due to loads generated by differences in thickness and vertical position of the new deck relative to the existing deck.

[0009] In view of the above background, the present invention aims to provide a joint structure between an unremoved portion of an existing deck slab and a pre-renewed portion of a new deck slab, which can be used for a relatively long period of time when the new deck slab differs from the existing deck slab in thickness and / or vertical position, and to provide a deck replacement construction method that incorporates said joint structure. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, one aspect of the present invention is a joint structure between an existing concrete deck (12) and a new concrete deck (13) arranged on a bridge girder (4) of a bridge (1), the joint structure comprising an unremoved portion (12a) of the existing deck, a prior renewal portion (13a) of the new deck that is installed while the unremoved portion remains, a connection main portion (11) including a precast concrete deck portion (27) arranged between the unremoved portion and the prior renewal portion, a first filler portion (14) that connects the deck portion of the connection main portion to the unremoved portion, and a second filler portion (15) that connects the deck portion of the connection main portion to the prior renewal portion, the deck portion of the connection main portion including a reinforcing bar (29) and a concrete portion (31) in which the reinforcing bar is embedded, the unremoved portion being oriented in the bridge axis direction and including the first filler portion (27) of the first deck portion (27). and the advance renewal section includes a first end face (18) connected to the second inter-renewal section, the advance renewal section including a second end face (26) facing the bridge axis direction and connected to the second inter-renewal section, the second end face differing from the first end face in thickness and / or its vertical position relative to the bridge girder, the first end face, the second end face, and the concrete part of the deck section of the connection main part each include a main body portion (12c, 25a, 31d) that determines the deck thickness and a haunch portion (12d, 25b, 31e) that bulges downward from the main body portion and connects to the upper surface of the bridge girder, and the cross-sectional shape perpendicular to the bridge axis direction of the portion (31a) of the main body portion of the concrete part of the deck section of the connection main part having the largest deck thickness includes the outer contours of the main body portion of the first end face and the main body portion of the second end face when viewed from the bridge axis direction.

[0011] According to this embodiment, the deck part of the connection main part has a cross section that includes the outer contours of the first end face and the second end face when viewed from the bridge axis direction, so the difference in cross-sectional shape can be absorbed by the connection main part, and deterioration and damage caused by the difference in cross section between the existing deck slab and the new deck slab can be suppressed even if used for a relatively long period of time such as several months to several years. Also, because the deck part of the connection main part is a precast concrete member, the construction period can be shortened.

[0012] In the above aspect, the reinforcing bar (29) of the deck portion (27) of the main connection portion (11) includes a first reinforcing bar (32a) that is partially embedded in the concrete portion (31) and protrudes from the concrete portion toward the unremoved portion, and the unremoved portion (12a) includes an existing concrete portion (17) and an existing protruding reinforcing bar (16a) that is partially embedded in the existing concrete portion and protrudes from the existing concrete portion toward the deck portion of the main connection portion, and the first reinforcing bar (32a) of the unremoved portion (12a) includes an existing concrete portion (17) and an existing protruding reinforcing bar (16a) that is partially embedded in the existing concrete portion and protrudes from the existing concrete portion toward the deck portion of the main connection portion, The filling portion (14) includes a joint reinforcing bar (34) connected to the existing protruding reinforcing bar (16a) and extending in the bridge axis direction, a portion of the first reinforcing bar protruding from the concrete portion, a portion of the existing protruding reinforcing bar protruding from the existing concrete portion, and a first filling concrete portion (36) in which the joint reinforcing bar is embedded, and the free ends (32d, 34a) of the joint reinforcing bar and the first reinforcing bar bulge in the radial direction, and the joint reinforcing bar and the first reinforcing bar may form an open lap joint.

[0013] According to this embodiment, the free ends of the joint reinforcing bar and the first reinforcing bar are bulged, so that the joint reinforcing bar and the first reinforcing bar are fixed not only by adhesion between the linearly extending portion and the concrete, but also by the bearing pressure of the bulging portion, thereby shortening the fixed length and shortening the length of the first spacer portion in the bridge axis direction. In addition, because the joint reinforcing bar and the first reinforcing bar form a gap lap joint, even if the actual reinforcing bar arrangement is not the same as the design drawing at the time of construction, there is no need to adjust the position of the first reinforcing bar 32a relative to the existing protruding reinforcing bar 16a at the site.

[0014] In the above-mentioned aspect, the reinforcing bar (29) of the deck slab portion (27) of the main connection portion (11) further includes a second reinforcing bar (32b) that is partially embedded in the concrete portion and protrudes from the concrete portion toward the prior renewal portion, the prior renewal portion (13a) includes a newly constructed concrete portion (25) and a stainless steel reinforcing bar (23a) that is partially embedded in the newly constructed concrete portion and protrudes from the newly constructed concrete portion toward the deck slab portion of the main connection portion to form a joint with the second reinforcing bar, and the second interfacial filling portion (15) includes a second interfacial filling concrete portion (37) that embeds the portion of the second reinforcing bar protruding from the concrete portion and the portion of the stainless steel reinforcing bar protruding from the newly constructed concrete portion.

[0015] According to this embodiment, when the unremoved portion and the main connection portion of the existing deck are removed and the subsequent renewal portion of the new deck is constructed, even if the second filling concrete portion is removed, the rust-preventive performance of the stainless steel reinforcing bars 23a embedded therein does not deteriorate. Therefore, even if the stainless steel reinforcing bars are used in conjunction with the reinforcing bars of the subsequent renewal portion, they do not adversely affect the durability of the new deck.

[0016] In the above-mentioned aspect, the outer contour of the surface facing the advance renewal section in the concrete portion of the deck portion (27) of the main connection part (11) preferably coincides with the outer contour of the second end face (26) of the advance renewal section (13a) when viewed from the bridge axis direction.

[0017] According to this aspect, the stainless steel reinforcing bar can be connected with the same structure both to the main connection part and to the part that will be placed after the main connection part is removed.

[0018] One aspect of the present invention is a method for replacing a deck (5) installed on a bridge girder (4) of a bridge (1), comprising the steps of removing a predetermined section (12b) in the bridge axis direction of the existing deck (12), constructing a preliminary renewal section (13a) of a new deck (13) in the section from which the existing deck was removed, and installing a connection main section (11) including a deck section (27) made of precast concrete between the unremoved section (12a) of the existing deck and the preliminary renewal section of the new deck, and connecting the deck section of the connection main section to the unremoved section and the preliminary renewal section. The method includes the steps of pouring concrete between the unremoved portion and the deck slab of the connection main portion to form a first interfacial filling portion (14), pouring concrete between the advance renewal portion and the deck slab of the connection main portion to form a second interfacial filling portion (15), putting the road including the unremoved portion, the advance renewal portion, and the connection main portion into service, suspending the service of the road after a predetermined period of time has elapsed since the start of service of the road, removing the unremoved portion and the connection main portion, and removing the unremoved portion and the connection main portion. and constructing a subsequent renewal section (13b) of the newly constructed deck in the section and connecting the subsequent renewal section to the preceding renewal section, wherein the deck section (27) of the main connection section (11) includes a reinforcing bar (29) and a concrete section (31) in which the reinforcing bar is partially embedded, the unremoved section includes a first end face (18) facing the bridge axis direction and connected to the first filling section, the preceding renewal section includes a second end face (26) facing the bridge axis direction and connected to the second filling section, and the second end face is a thickness and / or a vertical position relative to the bridge girder that is smaller than the first end face (13b). Unlike the above, each of the first end face, the second end face, and the concrete part of the deck part of the connection main part includes a main body portion (12c, 25a, 31d) that determines the deck thickness, and a haunch portion (12d, 25b, 31e) that bulges downward from the main body portion and connects to the upper surface of the bridge girder, and the cross-sectional shape perpendicular to the bridge axis direction of the part (31a) having the greatest deck thickness in the main body portion of the concrete part of the deck part of the connection main part includes the outer contours of the main body portion of the first end face and the main body portion of the second end face when viewed from the bridge axis direction.

[0019] According to this embodiment, the deck part of the connection main part has a cross section that includes the outer contours of the first end face and the second end face when viewed from the bridge axis direction, so the deck part of the connection main part can absorb differences in cross-sectional shape, and deterioration and damage caused by differences in the cross sections of the existing deck and the new deck can be suppressed even after a relatively long period of use of several months to several years. In addition, because the deck part of the connection main part is a precast concrete member, the construction period can be shortened. Effect of the Invention

[0020] According to the above aspects, in cases where the newly constructed deck differs from the existing deck in terms of thickness and / or vertical position, a joint structure can be provided between the unremoved portion of the existing deck and the pre-renewed portion of the newly constructed deck, which can be used for a relatively long period of time, and a deck replacement construction method incorporating this joint structure can be provided. [Brief description of the drawings]

[0021] [Figure 1] Side view of a bridge according to an embodiment [Diagram 2] FIG. 1 is a perspective view of a joint structure according to an embodiment, as viewed from above; [Diagram 3] FIG. 1 is a partially sectional perspective view of a bonding plate according to an embodiment; [Figure 4] An explanatory diagram showing the deck replacement method according to the embodiment (before construction) [Diagram 5] An explanatory diagram showing the replacement method of the deck according to the embodiment (partial removal of the existing deck) [Figure 6] An explanatory diagram showing the replacement method of the deck according to the embodiment (installation of the advance renewal part of the new deck) [Figure 7] An explanatory diagram showing the replacement method of the floor slab according to the embodiment (reinforcing bar joint between the existing floor slab and the joint slab) [Figure 8] An explanatory diagram showing the replacement method of the deck according to the embodiment (construction of the filling part) [Figure 9] An explanatory diagram showing the replacement method of the deck according to the embodiment (removal of the remaining part of the existing deck and the main connection part) [Figure 10] An explanatory diagram showing the replacement method of the deck according to the embodiment (installation of the subsequent renewal part of the new deck) [Figure 11]An explanatory diagram showing the replacement method of the deck according to the embodiment (removal of the second interfitting part) [Figure 12] An explanatory diagram showing the replacement method of the deck according to the embodiment (installation of the subsequent renewal part of the new deck) [Figure 13] An explanatory diagram showing the replacement method of the deck according to the embodiment (construction of the filling part) [Figure 14] FIG. 1 is a perspective view of a joint structure according to an embodiment, as viewed from below; 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 side view of a bridge 1 to which this embodiment is applied. As shown in Fig. 1, the bridge 1 is a road bridge including an abutment 2, a pier 3, a bridge girder 4 supported by the abutment 2 and the pier 3, a deck 5 provided on the bridge girder 4, and a pavement 6 laid on the upper surface of the deck 5. The bridge girder 4 has a steel truss as a main girder. The deck 5 is made of reinforced concrete. The deck replacement work is a work to remove the deck 5 and the pavement 6 and to lay a new deck 5 and pavement 6 on the existing bridge girder 4.

[0023] A road 7 is provided below the bridge 1 so as to intersect with the bridge 1 in plan view. Scaffolding (not shown) for the bridge 1 deck replacement work needs to be installed above the road 7 as well. When installing scaffolding above the road 7, the road 7 needs to be closed to traffic in case materials fall, but this requires time for consultation with the administrator of the road 7. Therefore, in the construction according to this embodiment, the deck 5 on the right side of the page in FIG. 1 is replaced first, the construction is suspended and the bridge 1 is temporarily put into service, and after the consultation is completed, the bridge 1 is taken out of service and the deck 5 on the left side of the page in FIG. 1, including the part above the road 7, is replaced.

[0024] Fig. 2 is a perspective view of a connection structure 10 according to an embodiment, and Fig. 3 is a partially sectional perspective view of a connection main part 11 according to an embodiment. As shown in Figs. 2 and 3, the connection structure 10 includes an unremoved part 12a of an existing deck 12 (see Fig. 4), a preceding renewal part 13a of a new deck 13 (see Fig. 13), a connection main part 11 arranged between the unremoved part 12a and the preceding renewal part 13a, a first space-filling part 14 that connects the connection main part 11 to the unremoved part 12a, and a second space-filling part 15 that connects the connection main part 11 to the preceding renewal part 13a.

[0025] The existing deck 12 is made of reinforced concrete and includes existing rebars 16 and an existing concrete section 17 in which the existing rebars 16 are embedded (see FIG. 4). The unremoved section 12a of the existing deck 12 has a first end face 18 facing the connection main section 11 in the bridge axis direction (see FIG. 6). A plurality of existing protruding rebars 16a protrude from the first end face 18 (see FIG. 6). As shown in FIG. 2, an existing wall balustrade 19 is erected at both ends of the existing deck 12 in the bridge width direction. The existing deck 12 includes a main body section 12c that defines the deck thickness and has a flat plate shape, and a haunch section 12d that bulges downward from the bottom surface of the main body section 12c so as to extend in the bridge axis direction and connects to the top surface of the main girder of the bridge girder 4 (see FIG. 14). The first end surface 18 includes a surface of the main body portion 12c and a surface of the haunch portion 12d.

[0026] A new wall parapet 20 is erected on both ends in the bridge width direction of the new deck 13 (see Fig. 13) (the existing wall parapet 19 and the new wall parapet 20 are omitted from Figs. 3 to 13). The new deck 13 may be constructed by manufacturing the deck portion and the new wall parapet 20 as separate precast concrete members and joining them together on-site, or may be constructed using a precast concrete member in which the deck portion and the new wall parapet 20 are integrated. The connection PCa deck member 21 arranged adjacent to the connection main part 11 in the advance renewal part 13a of the new deck 13 includes, in the part constituting the new deck 13, bridge axis perpendicular direction reinforcing bars 22 extending in the bridge width direction (direction perpendicular to the bridge axis) and arranged in two upper and lower tiers, bridge axis direction reinforcing bars 23 extending in the bridge axis direction and arranged in two upper and lower tiers, tension members 24 extending in the bridge width direction and arranged in two upper and lower tiers, and a newly constructed concrete part 25 in which the bridge axis perpendicular direction reinforcing bars 22, the bridge axis direction reinforcing bars 23, and the tension members 24 are embedded. For example, if the length of the connection PCa deck member 21 in the bridge axis direction is set to about 2 m, it is preferable to select the number of tension members 24 to be arranged so as to satisfy the design conditions and arrange them separately on the top and bottom. The newly constructed concrete section 25 has a flat plate shape with a predetermined deck thickness and includes a main body section 25a that is rectangular in plan view, and a haunch section 25b that bulges downward from the underside of the main body section 25a so as to extend in the bridge axis direction and is connected to the upper surface of the main girder of the bridge girder 4 via non-shrink mortar (not shown) (see Figure 14).

[0027] Both ends of the bridge axis direction reinforcing bar 23 in the bridge axis direction protrude in a loop shape from the newly constructed concrete portion 25. The newly constructed concrete portion 25 has a second end face 26 facing the main connection portion 11 in the bridge axis direction. When salt damage countermeasures are required, the portion of the bridge axis direction reinforcing bar 23 protruding from the second end face 26 is composed of a stainless steel reinforcing bar 23a. The stainless steel reinforcing bar 23a is, for example, a stainless steel deformed bar for reinforced concrete as specified in JIS G 4322. The stainless steel reinforcing bar 23a is connected to another steel bar forming a part of the bridge axis direction reinforcing bar 23 in the newly constructed concrete portion 25. The portion of the bridge axis direction reinforcing bar 23 other than the stainless steel reinforcing bar and the bridge axis transverse reinforcing bar 22 are preferably made of a steel bar for reinforced concrete as specified in JIS G 3112 that has been coated with epoxy resin. The second end face 26 includes the surface of the main body portion 25a and the surface of the haunch portion 25b.

[0028] The tendons 24 are made of PC steel bars, PC steel wires or PC steel strands, or fiber-reinforced plastics such as aramid fiber, carbon fiber or glass fiber, and apply prestress to the newly constructed concrete section 25. In order to reduce the burden on the construction site, it is preferable that the prestress by the tendons 24 be introduced by a pretensioning method at a precast concrete manufacturing plant.

[0029] The main connection part 11 includes a deck slab part 27 and a wall balustrade part 28 erected on both ends of the deck slab part 27 in the bridge width direction. The deck slab part 27 is a precast concrete member, and the wall balustrade part 28 is a cast-in-place concrete member. In the deck slab part 27, the main connection part 11 includes reinforcing bars 29, tendons 30 extending in the bridge width direction, and concrete parts 31 in which the reinforcing bars 29 and tendons 30 are embedded. The reinforcing bars 29 include reinforcing bars 22 perpendicular to the bridge axis arranged in two upper and lower rows extending in the bridge width direction, and bridge axis direction reinforcing bars 32 extending in the bridge axis direction. The bridge axis direction reinforcing bars 32 include a first reinforcing bar 32a protruding from the concrete portion 31 toward the unremoved portion 12a, a second reinforcing bar 32b protruding in a loop shape from the concrete portion 31 toward the prior renewal portion 13a, and a third reinforcing bar 32c protruding from the concrete portion 31 toward the unremoved portion 12a above the first reinforcing bar 32a. The main portions of the bridge axis direction reinforcing bars 32 are arranged in two tiers, upper and lower.

[0030] The first reinforcing bars 32a are arranged in two tiers, one above the other, at the same height as the existing protruding reinforcing bars 16a of the unremoved portion 12a in the design drawing of the existing deck 12, but offset in the bridge width direction, and extend in the bridge axis direction. The base end of the first reinforcing bar 32a is embedded in the concrete portion 31, and the free end of the first reinforcing bar 32a protruding from the concrete portion 31 forms a bulging portion 32d that bulges in the radial direction. The bulging portion 32d is preferably in the shape of a truncated cone that tapers toward the unremoved portion 12a. The second reinforcing bar 32b is provided so as to form a loop joint with the stainless steel reinforcing bar 23a of the connecting portion PCa deck member 21. The portion of the third reinforcing bar 32c protruding from the concrete portion 31 is inclined downward with respect to the bridge axis direction.

[0031] The tendon 30 may have a configuration similar to that of the tendon 24 of the connection portion PCa deck member 21.

[0032] The upper surface of the concrete portion 31 in the deck portion 27 extends in a plane at the same vertical position as the upper surface of the preceding renewal portion 13a with respect to the bridge girder 4 (see FIG. 1). The concrete portion 31 includes a first section 31a provided on the unremoved portion 12a side in the bridge axis direction and having a predetermined thickness, a second section 31b provided on the preceding renewal portion 13a side in the bridge axis direction and having the same thickness as the preceding renewal portion 13a, and an intermediate section 31c provided between the first section 31a and the second section 31b and having an inclined lower surface so as to connect the lower surface of the first section 31a and the lower surface of the second section 31b. As shown in FIG. 3 and FIG. 14, the concrete portion 31 includes a main body portion 31d that defines the deck thickness in each of the first to third sections 31a to 31c, and a haunch portion 31e that bulges downward from the main body portion 31d, extends in the bridge axis direction, and is connected to the upper surface of the main girder of the bridge girder 4 via non-shrink mortar (not shown). In the first section 31a, the lower surface of the main body 31d extends in a plane at the same vertical position as the lower surface of the main body 12c of the first end surface 18 of the unremoved section 12a with respect to the bridge girder 4. In addition, in the first section 31a to the third section 31c, the lower surface of the haunch 31e is higher in the vertical direction than the lower surface of the haunch 12d of the unremoved section 12a with respect to the bridge girder 4 (see FIG. 1) to provide a gap between the upper surface of the main girder of the bridge girder 4 and the lower surface of the main girder 31e for filling a filler (not shown) such as non-shrink mortar, and extends in a plane at the same vertical position as the lower surface of the haunch 25b of the preceding renewal section 13a. The lower surface of the main body 31d in the second section 31b extends in a plane at the same vertical position as the lower surface of the main body 25a of the preceding renewal section 13a with respect to the bridge girder 4 (see FIG. 1). The side surface of the haunch portion 31e of the second section 31b is located outward in the bridge width direction from the haunch portion 25b of the preceding renewal section 13a. Therefore, the first section 31a is the portion with the greatest deck thickness in the deck section 27 of the main connection section 11, and the cross-sectional shape perpendicular to the bridge axis direction of the main body portion 31d of the first section 31a includes the outer contour of the main body portion 12c of the first end face 18 of the unremoved section 12a and the main body portion 25a at the second end face 26 of the preceding renewal section 13a when viewed from the bridge axis direction.

[0033] As shown in Figures 3 and 7, the first filling section 14 includes a bridge axis perpendicular reinforcing bar 22 extending in the bridge width direction, a mechanical joint 33 attached to the protruding end of the existing protruding reinforcing bar 16a protruding from the unremoved section 12a, a joint reinforcing bar 34 attached to the mechanical joint 33 at its base end, a bridge axis direction reinforcing bar 35 arranged overlapping with a third reinforcing bar 32c protruding from the concrete section 31 of the main connection section 11, and a first filling concrete section 36 poured between the unremoved section 12a and the concrete section 31 of the main connection section 11, in which the bridge axis perpendicular reinforcing bar 22, the protruding portion of the existing protruding reinforcing bar 16a, the mechanical joint 33, the joint reinforcing bar 34 and the bridge axis direction reinforcing bar 35 are embedded.

[0034] The free end of the joint reinforcing bar 34 forms a bulging portion 34a that bulges in the radial direction. The bulging portion 34a preferably has a truncated cone shape that tapers toward the concrete portion 31 of the main connection part 11. The joint reinforcing bar 34 forms an open lap joint with the first reinforcing bar 32a that protrudes from the concrete portion 31 of the main connection part 11.

[0035] The upper surface of the first concrete filling section 36 is inclined downward toward the unremoved section 12a so as to connect the upper surface of the concrete section 31 of the connection main section 11 and the upper surface of the unremoved section 12a. The bridge axis direction reinforcing bar 35 has a portion along this upper surface. The lower surface of the first concrete filling section 36 is located on an extension plane of the lower surface of the concrete section 31 of the first section 31a of the connection main section 11. Also, a haunch portion is formed in the first concrete filling section 36 on an extension line of the haunch portion 31e of the connection main section 11, and its lower surface is located above the lower surface of the haunch portion 12d of the unremoved section 12a (see FIG. 14). Non-shrink mortar (not shown) is filled in the portion of the difference in height between the vertical positions of the lower surfaces of the haunch portions 25b and 31e.

[0036] As shown in FIG. 3, the second interfacial filling section 15 includes the bridge axis perpendicular reinforcing bar 22 and the second interfacial filling concrete section 37, which is cast between the advance renewal section 13a and the concrete section 31 of the connection main section 11 and embeds the bridge axis perpendicular reinforcing bar 22, the portion of the stainless steel reinforcing bar 23a protruding from the advance renewal section 13a, and the portion of the second reinforcing bar 32b protruding from the concrete section 31. The upper surface of the second interfacial filling concrete section 37 is located on an extension plane of the upper surface of the advance renewal section 13a and the upper surface of the concrete section 31 of the connection main section 11. The lower surface of the second interfacial filling concrete section 37 is located on an extension plane of the lower surface of the advance renewal section 13a and the lower surface of the concrete section 31 of the second section 31b in the connection main section 11. Therefore, the second interfacial filling concrete section 37 has a flat plate shape with a predetermined thickness except for the haunch portion on the main girder. A first wall high transom filling portion 14a is erected at both ends of the first inter-spaced portion 14 in the bridge width direction, and a second wall high transom filling portion 15a is erected at both ends of the second inter-spaced portion 15 in the bridge width direction.

[0037] A replacement method for the deck slab 5 (see FIG. 1) according to the embodiment will be described with reference to FIGS.

[0038] As shown in Figure 4, the existing deck 12 is divided in the bridge axis direction into an unremoved portion 12a extending from one end in the bridge axis direction to a predetermined position, and a previously removed portion 12b extending from the predetermined position to the other end in the bridge axis direction.

[0039] As shown in Figures 4 and 5, workers remove the pre-removal portion 12b of the existing deck 12. The pre-removal portion 12b is removed, for example, by cutting the pre-removal portion 12b into blocks of a predetermined size with a concrete cutter (not shown) and removing the cut blocks with a lifting machine (not shown). The workers pull out the cut surface by a water jet method or the like so that the end of the existing protruding rebar 16a protrudes from the first end face 18.

[0040] Next, as shown in FIG. 6, on the bridge girder 4 (see FIG. 1) from which the existing deck 12 has been removed, the worker places the deck part 27 of the connection main part 11 in a position adjacent to the unremoved part 12a, places the connection part PCa deck member 21 in a position adjacent to the deck part 27 of the connection main part 11, and places multiple general part PCa deck members 38 in the remaining section. The general part PCa deck member 38 is configured in the same manner as the connection part PCa deck member 21, except that the stainless steel rebar 23a is not used for the bridge axial direction rebar 39. The deck part 27 of the connection main part 11, the connection part PCa deck member 21, and the general part PCa deck member 38 are manufactured in a precast concrete factory, transported to the construction site, and placed in a predetermined position by a lifting machine (not shown). The connection PCa deck member 21 and the adjacent general PCa deck member 38 are arranged so that the portions of the bridge axis direction reinforcing bars 23, 39 that protrude from the newly constructed concrete portion 25 form a loop joint. Adjacent general PCa deck members 38 are also arranged so that the portions of the bridge axis direction reinforcing bars 39 that protrude from the newly constructed concrete portion 25 form a loop joint. After the connection PCa deck member 21 and the general PCa deck member 38 are arranged in predetermined positions, non-shrink mortar (not shown) is filled between the bottom surfaces of their haunch portions 25b (see FIG. 14) and the top surface of the bridge girder 4 (see FIG. 1).

[0041] FIG. 7(A) shows a part of the deck section 27 of the unremoved section 12a and the main connection section 11. As shown in FIG. 7(B), after placing the deck section 27 in a predetermined position, the worker connects the mechanical joint 33 to the free end of the existing protruding rebar 16a protruding from the first end face 18 of the unremoved section 12a. Next, as shown in FIG. 7(C), the worker connects the base end of the joint rebar 34 to the mechanical joint 33 so that the bulging portion 34a faces the concrete portion 31 of the deck section 27. Next, as shown in FIG. 7(D), the worker places the bridge axis direction rebar 35, which is placed overlapping the third rebar 32c protruding from the concrete portion 31 of the deck section 27, between the unremoved section 12a and the concrete portion 31 of the deck section 27.

[0042] Next, as shown in Fig. 8, workers place reinforcing bars 22 perpendicular to the bridge axis between the concrete part 31 of the deck part 27 of the main connection part 11 and the first end face 18 of the unremoved part 12a and pour concrete, thereby forming the first interfitting part 14. In addition, workers place reinforcing bars 22 perpendicular to the bridge axis between the concrete part 31 of the deck part 27 and the newly constructed concrete part 25 of the connection part PCa deck member 21 and pour concrete, thereby forming the second interfitting part 15.

[0043] In addition, a third filling section 40 is provided between the newly constructed concrete sections 25 of the adjacent joint PCa slab members 21 and the general PCa slab members 38, and between the newly constructed concrete sections 25 of the adjacent general PCa slab members 38. The third filling section 40 includes the bridge axis perpendicular direction reinforcing bars 22 extending in the bridge width direction, and a third filling concrete section 41 that is poured between the adjacent newly constructed concrete sections 25 and buries the parts of the bridge axis perpendicular direction reinforcing bars 22 and the bridge axis direction reinforcing bars 39 that protrude from the newly constructed concrete sections 25. A worker places the bridge axis perpendicular direction reinforcing bars 22 and pours concrete between the adjacent newly constructed concrete sections 25 to form the third filling section 40.

[0044] Next, workers lay pavement 6 on the deck 5 including the unremoved portion 12a and the prior renewal portion 13a (see FIG. 1). It is preferable that the pavement 6 be laid on top of the existing pavement 6 near the first interfill portion 14 in the unremoved portion 12a so that the slope caused by the difference in height between the top surface of the unremoved portion 12a and the top surface of the prior renewal portion 13a is gentle. At this stage, construction is temporarily suspended and the bridge 1 is temporarily put into service.

[0045] When the consultation between the administrator of the bridge 1 and the administrator of the road 7 is completed and preparations are made to replace the deck 5 on the left side of the paper in FIG. 1, including the part above the road 7, by installing scaffolding for deck replacement above the road 7, the bridge 1 will be suspended from service (see FIG. 1). As shown in FIG. 9, workers remove the unremoved part 12a of the existing deck 12, the connection main part 11, and the first interfacial filling part 14. The removal is performed in the same manner as the preceding removal part 12b. The cutting surface provided in the bridge width direction closest to the preceding renewal part 13a side is the boundary surface between the second interfacial filling part 15 and the concrete part 31 of the connection main part 11 or a surface in the vicinity thereof, so as not to cut the bridge axis direction reinforcing bars 39 of the connection part PCa deck member 21.

[0046] Next, as shown in Fig. 10, workers use a lifting machine (not shown) to install multiple general PCa deck members 38 on the bridge girder 4 (see Fig. 1) of the newly removed section, except for the one closest to the preceding renewal section 13a. Although not shown, in the succeeding renewal section 13b, similarly to the preceding renewal section 13a, the general PCa deck members 38 are arranged so that the parts of the bridge axis direction reinforcing bars 39 protruding from the newly constructed concrete section 25 form loop joints between the adjacent general PCa deck members 38. After the arrangement, non-shrink mortar (not shown) is filled between the lower surface of the general PCa deck member 38 and the upper surface of the bridge girder 4 (see Fig. 1).

[0047] Next, as shown in Figures 10 and 11, the worker removes the second interfacial concrete portion 37 using a water jet method or the like, thereby exposing the portion of the stainless steel reinforcing bar 23a that was embedded in the second interfacial concrete portion 37.

[0048] Next, as shown in FIG. 12, the worker places the last general PCa slab member 38 between the preceding renewal section 13a and the general PCa slab member 38 already installed in the succeeding renewal section 13b. The last general PCa slab member 38 is also placed so that the portion of the bridge axis direction reinforcing bar 39 protruding from the newly constructed concrete section 25 forms a loop joint with the stainless steel reinforcing bar 23a of the adjacent connection PCa slab member 21 and the bridge axis direction reinforcing bar 39 of the adjacent general PCa slab member 38. After placement, non-shrink mortar (not shown) is filled between the bottom surface of the general PCa slab member 38 and the top surface of the bridge girder 4 (see FIG. 1).

[0049] Next, as shown in Figure 13, workers place reinforcing bars 22 perpendicular to the bridge axis between the newly constructed concrete sections 25 of the adjacent connection section PCa deck members 21 and general section PCa deck members 38, and between the newly constructed concrete sections 25 of the adjacent general section PCa deck members 38, and pour concrete to form the third interfacial section 40. In this way, the new deck 13 is constructed. Workers lay the pavement 6 (see Figure 1) on the new deck 13.

[0050] The effects of the above embodiment will be described with reference to FIGS.

[0051] The cross section perpendicular to the bridge axis direction of the first section 31a of the deck portion 27 of the connection main part 11 has a shape in the main body portion 31d that encompasses the outer contours of the main body portion 12c of the unremoved portion 12a of the existing deck 12 and the main body portion 25a of the advance updated portion 13a of the new deck 13 when viewed from the bridge axis direction. Therefore, the deck portion 27 of the connection main part 11 can absorb the differences in cross-sectional shapes, and even when used for a relatively long period of time, such as several months to several years, deterioration and damage due to differences in the cross sections of the existing deck 12 and the new deck slab 13 can be suppressed.

[0052] Furthermore, since the outer contour of a cross section perpendicular to the bridge axis direction of the main body part 31d in the second section 31b of the deck part 27 of the connection main part 11 matches the outer contour of the main body part 25a at the second end face 26 of the newly constructed concrete part 25 of the connection part PCa deck member 21 when viewed from the bridge axis direction, the connection part PCa deck member 21 can be connected in the same structure to both the connection main part 11 forming the connection structure 10 and the general part PCa deck member 38 forming the newly constructed deck 13. In other words, there is no need to change the shape of the stainless steel reinforcing bar 23a after removing the second interfacial concrete part 37.

[0053] Since the first reinforcing bar 32a and the joint reinforcing bar 34, which form a gapped lap joint, have bulges 32d, 34a at their free ends, they are fixed not only by adhesion between the straight part of the reinforcing bar and the concrete, but also by the support pressure of the bulges 32d, 34a, so that the fixed length can be shortened and the length of the first interfitting section 14 in the bridge axis direction can be shortened. In addition, the existing reinforcing bars 16 are not necessarily arranged according to the design drawings, and their exact positions are unknown, but the joint reinforcing bar 34 connected to the existing protruding reinforcing bar 16a forms a gapped lap joint with the first reinforcing bar 32a of the deck slab section 27 of the main connection section 11, so that it is not necessary to adjust the position of the first reinforcing bar 32a relative to the existing protruding reinforcing bar 16a.

[0054] The second concrete filling section 37 is removed when the subsequent renewal section 13b is constructed. When salt damage countermeasures are required, epoxy resin-coated rebars are often used as rebars in the concrete slab to enhance rust-prevention performance. When removing the second concrete filling section 37 by water jet construction or the like, if the rebars embedded therein are epoxy resin-coated rebars, the paint peels off and the rust-prevention performance deteriorates. The stainless steel rebars 23a embedded in the second concrete filling section 37 do not deteriorate in rust-prevention performance even when subjected to water pressure or the like for removing the second concrete filling section 37, and the durability of the new slab 13 is not adversely affected even when used in conjunction with the bridge-axis direction rebars 39 of the subsequent renewal section 13b.

[0055] Not only the connection PCa deck member 21 and the general PCa deck member 38, but also the deck member 27 of the main connection part 11 are precast concrete members, so that on-site labor can be reduced and construction time can be shortened.

[0056] Although the description of the specific embodiment has been completed above, the present invention is not limited to the above embodiment and modified examples, and can be modified in a wide range of ways. The main girder may be a steel structure other than a truss, such as an I-girder or a box girder. [Explanation of symbols]

[0057] 10: Connection structure 11: Main connection part 12: Existing deck 12a: Unremoved section 12c: Main body 12d: Haunch 13: New deck 13a: Advance update part 14: 1st filling section 15:Second filling section 16a: Existing protruding rebar 17: Existing concrete section 18: First end surface 21: PCa slab joint 23a: Stainless steel rebar 25: Newly constructed concrete section 25a: Main body 25b: Haunch 26: Second end face 29: Reinforcement bar 31: Concrete section 31a: First Section 31b: Second Section 31d: Main body 31e: Haunch 32a: First rebar 32b: Second rebar 32d:bulge 33: Mechanical coupling 34: Reinforced concrete joint 34a:bulge 36: First concrete filling section 37: Second concrete filling section 38: General PCa deck member 40: 3rd filler section

Claims

1. A joint structure between an existing concrete deck and a new concrete deck placed on the bridge girder of a bridge, An unremoved portion of the existing deck; A pre-renewal portion of the new deck that is installed with the unremoved portion remaining; A connection main section including a precast concrete deck section arranged between the unremoved section and the advance renewal section; A first space filling portion that connects the deck portion of the connection main portion to the unremoved portion; A second filler section that connects the deck section of the connection main section to the advance renewal section; Equipped with The deck portion of the main connection portion includes a reinforcing bar and a concrete portion in which the reinforcing bar is embedded, The unremoved portion includes a first end surface facing the bridge axis direction and connected to the first filling portion, The advance renewal portion includes a second end surface facing the bridge axis direction and connected to the second filling portion, The second end surface is different from the first end surface in thickness and / or vertical position relative to the bridge girder, Each of the first end surface, the second end surface, and the concrete portion of the deck portion of the connection main portion includes a main body portion that defines a deck thickness and a haunch portion that bulges downward from the main body portion and is connected to the upper surface of the bridge girder, A joint structure in which the cross-sectional shape perpendicular to the bridge axis direction of the part of the main body part of the concrete part of the deck slab of the connection main part, which has the greatest deck thickness, includes the outer contours of the main body part of the first end face and the main body part of the second end face when viewed from the bridge axis direction.

2. The reinforcing bars of the deck portion of the connection main portion include a first reinforcing bar that is partially embedded in the concrete portion and protrudes from the concrete portion toward the unremoved portion, The unremoved portion includes an existing concrete portion and an existing protruding rebar that is partially embedded in the existing concrete portion and protrudes from the existing concrete portion toward the deck portion of the connection main portion, The first interfacial filling portion includes a joint reinforcing bar that is connected to the existing protruding reinforcing bar and extends in the bridge axis direction, a portion of the first reinforcing bar that protrudes from the concrete portion, a portion of the existing protruding reinforcing bar that protrudes from the existing concrete portion, and a first interfacial filling concrete portion in which the joint reinforcing bar is embedded, The joint structure according to claim 1 , wherein free ends of the joint reinforcing bar and the first reinforcing bar bulge in a radial direction, and the joint reinforcing bar and the first reinforcing bar form a gap lap joint.

3. The reinforcing bars of the deck section of the connection main section further include a second reinforcing bar partially embedded in the concrete section and protruding from the concrete section toward the preceding renewal section, The advance renewal portion includes a newly constructed concrete portion and a stainless steel reinforcing bar that is partially embedded in the newly constructed concrete portion, protrudes from the newly constructed concrete portion toward the deck portion of the connection main portion, and forms a joint with the second reinforcing bar; The joint structure described in claim 1, wherein the second interfacial filling portion includes a second interfacial filling concrete portion that embeds a portion of the second reinforcing bar protruding from the concrete portion and a portion of the stainless steel reinforcing bar protruding from the newly constructed concrete portion.

4. A joint structure as described in claim 3, wherein the outer contour of the surface facing the prior renewal portion in the concrete portion of the deck slab of the main connection portion coincides with the outer contour of the second end face of the prior renewal portion when viewed in the bridge axis direction.

5. A method for replacing decks installed on bridge girders, A step of removing a predetermined section in the bridge axis direction of the existing deck; A step of constructing a pre-renewal portion of a new deck in the section from which the existing deck has been removed; a step of installing a connection main section including a precast concrete slab section between the unremoved section of the existing slab and the advance renewal section of the new slab, and connecting the slab section of the connection main section to the unremoved section and the advance renewal section, the step including pouring concrete between the unremoved section and the slab section of the connection main section to form a first inter-space section, and pouring concrete between the advance renewal section and the slab section of the connection main section to form a second inter-space section; A step of putting into service a road including the unremoved section, the advance renewal section, and the connection main section; A step of ceasing service of the road after a predetermined period of time has elapsed since the start of service of the road; removing the unremoved portion and the main connection portion; constructing a subsequent renewal section of the new deck in the section from which the unremoved section and the main connection section have been removed, and connecting the subsequent renewal section to the preceding renewal section; Equipped with The deck portion of the connection main portion includes a reinforcing bar and a concrete portion in which the reinforcing bar is partially embedded, The unremoved portion includes a first end surface facing the bridge axis direction and connected to the first filling portion, The advance renewal portion includes a second end surface facing the bridge axis direction and connected to the second filling portion, The second end surface is different from the first end surface in thickness and / or vertical position relative to the bridge girder, Each of the first end surface, the second end surface, and the concrete portion of the deck portion of the connection main portion includes a main body portion that defines a deck thickness and a haunch portion that bulges downward from the main body portion and is connected to the upper surface of the bridge girder, A deck replacement construction method in which the cross-sectional shape perpendicular to the bridge axis direction of the part of the main body part of the concrete part of the deck section of the connection main part having the greatest deck thickness includes the outer contours of the main body part at the first end face and the main body part at the second end face when viewed from the bridge axis direction.

Images