Deck joint structure

Abstract

To provide a joint structure of a floor slab capable of reducing construction cost by shortening a width between joint end faces.SOLUTION: In a joint structure of the floor slab 1, a diameter-expanding bearing member 9 having a diameter larger than the diameter of a reinforcing bar is fixed to the end of the reinforcing bar 5, and storage parts 12,12.... opened to the opposite side for storing the diameter-expanding bearing member 9 are recessed in the joint ends of the opposed floor slab members 2 and 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a joint structure for deck slabs of an elevated road, a bridge, or the like, which is formed by joining a plurality of deck members in the bridge axis direction. [Background technology]

[0002] Deterioration due to salt damage and fatigue over time has become a problem for the RC decks that make up existing elevated roads and bridges, and in recent years, replacement work for deteriorated RC decks has been widely planned and implemented.

[0003] This type of deck replacement work requires minimizing the impact on traffic, shortening the on-site work process, and quickly putting the bridge into service.

[0004] Therefore, in recent years, a construction method has been widely adopted in which the existing RC deck is replaced with multiple precast concrete deck members joined together in the axial direction of the bridge to construct the deck.

[0005] This PCa deck generally uses deck members that are prestressed in either the bridge axis direction, the direction perpendicular to the bridge axis, or both.Precast concrete deck members (hereinafter referred to as PCa deck members) manufactured in a factory are transported to the site by trailer, etc., and the deck is constructed by joining the PCa deck members one by one in the bridge axis direction.

[0006] Conventionally, loop joints have been widely used to connect the PCa deck components, with loop reinforcement bars protruding from the joint end faces of opposing deck components at a distance from each other and overlapping each other, reinforcing bars oriented perpendicular to the bridge axis (hereinafter referred to as horizontal reinforcement bars) inserted into the curved parts of the loop reinforcement bars, and filler material such as concrete or mortar is filled between the PCa deck components, with the overlapping loop reinforcement bars and horizontal reinforcement bars embedded in the filler material.

[0007] This loop joint can be made shorter in length than a lap joint by effectively utilizing the support pressure acting on the curved portion of the loop reinforcement.

[0008] However, loop joints have the drawback of being cumbersome, requiring the loop reinforcement bars protruding from the opposing joint end faces to be overlapped, and then the horizontal reinforcing bars to be inserted into the curved edge of the loop reinforcement bars. Furthermore, limitations on the bending of the reinforcing bars (a minimum bending radius is specified) mean that the joint is unsuitable for thin deck slabs.

[0009] Furthermore, in loop joints, the arrangement of the loop reinforcement and horizontal reinforcing bars between the joint end faces is dense, which presents the problem of making it difficult to compact the filler material filled between the joint end faces.

[0010] Therefore, in recent years, as an alternative to loop joints, a construction method has been used in which the ends of the reinforcing bars protruding from the opposing end faces of PCa deck components placed abutting each other at a specified distance are overlapped, and concrete is poured into that area to connect the PCa deck components.

[0011] In this type of construction method, a joint structure (gap lap joint) has been developed in which a head with a diameter larger than the diameter of the rebar is provided at the end of the rebar protruding from the end face of the PCa deck member, and the length of the overlapping part (joint length) is made shorter than conventional ones due to the combined action of the adhesion force between the rebar and concrete and the bearing resistance force acting on the head (see, for example, Patent Document 1).

[0012] Furthermore, in deck joint structures that also use this gap lap joint, by using ultra-high strength fiber reinforced concrete (mortar) as the filler material filled between the joint end faces, the adhesion between the steel bars and the concrete and the bearing resistance acting on the head are further increased, and structures have been developed that omit the steel bars arranged perpendicular to the bridge axis between the joint end faces, thereby shortening the width between the joint end faces, and that provide continuous or intermittent ridge-shaped convex shear keys perpendicular to the bridge axis at approximately the center of the thickness direction of the joint surface of the PCa deck member, thereby improving shear resistance. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-11940 Summary of the Invention [Problem to be solved by the invention]

[0014] However, in the conventional technology described above, by using ultra-high strength fiber reinforced concrete (mortar) as the filler material filled between the joint end faces, the adhesive strength between the reinforcing bars and the concrete and the bearing resistance acting on the head can be further increased, and the reinforcing bars arranged perpendicular to the bridge axis between the joint end faces can be omitted, which has the great advantage of shortening the width between the joint end faces.However, because ultra-high strength fiber reinforced concrete (mortar) is expensive, this has the problem of increasing construction costs, and further reductions in construction costs are desired.

[0015] In view of the above-mentioned conventional problems, the present invention has been made with the object of providing a deck slab joint structure that can shorten the width between the joint end faces and reduce construction costs. [Means for solving the problem]

[0016] The feature of the invention described in claim 1 to solve the above-mentioned conventional problems is that in a deck formed by joining a plurality of deck members in the bridge axis direction, a plurality of protruding members are provided at intervals in the direction perpendicular to the bridge axis from the joint end faces of the opposing deck members. Screw-knotted rebar and protruding from the joint end surface of one of the opposing deck members. Screw-knotted rebar Between them, there is a protrusion from the joint end surface of the other deck member. Screw-knotted rebar In the joint structure of the deck slab in which a filler material is filled between the opposing deck slab members, Threaded rebar The storage section is opened on the other side into which the tip of the deck member is fitted, and is recessed in a planar arc-shaped or semi-elliptical groove shape that opens on the upper and / or lower surfaces of the deck member, The filler has a strength at least equal to or greater than that of high-strength fiber-reinforced concrete or high-strength fiber-reinforced mortar. A deck slab joint structure characterized by: The reason is that.

[0017] The invention described in claim 2 is characterized by the configuration of claim 1, as well as: Threaded rebar An expanded diameter support member having a diameter larger than the diameter of the reinforcing bar is fixed to the end of the support member, and the expanded diameter support member is accommodated in the storage section.

[0018] The invention as set forth in claim 3 is characterized in that, in addition to the configuration of claim 2, the expanded diameter support member comprises at least Threaded rebar The feature of the present invention is that the nut-type member is composed of a plurality of nut-type members which are threadedly engaged with threaded portions provided at the ends of the nut-type members.

[0019] The feature of the invention described in claim 4 is that, in addition to the configuration of claim 2 or 3, the storage section is positioned in a position where its end face side opening edge does not interfere with the bearing stress range of the expanded diameter bearing member.

[0020] The invention described in claim 5 is characterized in that, in addition to the configuration of any one of claims 1 to 4, Threaded rebar are arranged in a plurality of stages at intervals in the thickness direction of the deck slab, and adjacent ones of the joint end faces in the thickness direction of the deck slab Screw-knotted rebar The difference is that a recess or protrusion for a shear-resistant key is formed between the two.

[0021] The invention as set forth in claim 6 is characterized in that, in addition to the configuration of claim 5, the shear-resistant key recess has an arcuate or semi-elliptical shape in side view. [Effects of the Invention]

[0022] The reinforced concrete structure according to the present invention has the features of claim 1, Screw-knotted rebar By retracting the tip of the rebar into the storage section and shortening the overlap length with the other adjacent rebar between the joint end faces of the deck members, the width between the joint end faces of the joined deck members can be made shorter than before, reducing the amount of filler material to be filled between the joint end faces and thereby reducing costs.In addition, it is possible to avoid interference with the other joint member to which the rebar is joined when installing the deck members, and the adhesive area between the joint surface and the filler material is increased, improving the adhesion between the filler material and the deck members and avoiding stress concentration. Furthermore, the present invention further increases the adhesive strength between the reinforcing bars and the filler material, and the bearing resistance acting on the expanded bearing member, and further reduces the width between the joint end faces. Furthermore, since the required strength can be achieved even with high-strength fiber-reinforced concrete or high-strength fiber-reinforced mortar, material costs can be reduced accordingly.

[0023] Furthermore, in this invention, by incorporating the configuration of claim 2, in addition to the adhesive strength between the reinforcing bars themselves (straight sections) and the filler material, a compressive stress transmission area (compression strut) is formed in a predetermined direction (a direction forming a predetermined angle with the reinforcing bars) in the expanded diameter support members attached to adjacent reinforcing bars, and the expanded diameter support members support each other, so that the width between the joint end faces of the joined deck members can be made shorter than before, the amount of filler material to be filled between the joint end faces can be reduced, and costs can be saved accordingly.

[0024] Furthermore, in the present invention, by providing the configuration of claim 3, the position of the expanded diameter support member can be adjusted to an appropriate position at the work site.

[0025] Furthermore, in the present invention, by providing the configuration of claim 4, the expanded diameter bearing member can preferably exert bearing resistance.

[0026] Furthermore, in the present invention, by providing the configuration of claim 5, it is possible to improve shear resistance.

[0027] Furthermore, in the present invention, by incorporating the configuration of claim 6, the adhesive area between the joint surface and the filler material is increased, improving the shear strength between the filler material and the deck member, and also making it possible to avoid stress concentration. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a plan view showing an example of a joint structure of a deck according to the present invention. FIG. [Figure 2] FIG. [Figure 3] FIG. 2 is a plan view showing the state before filling with the filler material. [Figure 4] 3. (a) is a cross-sectional view taken along line AA in FIG. 3, and (b) is a cross-sectional view taken along line BB in FIG. [Figure 5] FIG. 10 is a plan view showing an example in which an expanded diameter bearing member is provided at the tip of a reinforcing bar in a deck slab joint structure according to the present invention. [Figure 6] This is a schematic rebar arrangement diagram to explain the effect of bearing resistance when an expanded diameter bearing member is provided at the tip of the above rebar. [Figure 7] FIG. 10 is a partially enlarged plan view showing another example of the diameter expansion support member of the same. [Figure 8] FIG. 2 is a vertical cross-sectional view showing the state when the deck member is installed. [Figure 9] (a) is a longitudinal cross-sectional view showing an embodiment of a deck slab joining structure equipped with the above-mentioned convex portion for shear key, and (b) is a longitudinal cross-sectional view showing an embodiment of a deck slab joining structure that uses both the same concave portion for shear key and the convex portion for shear key. [Figure 10] Graphs showing the results of bending load tests to confirm the effectiveness of the deck slab joint structure of the present invention, where (a) is a graph showing the relationship between vertical load and vertical displacement for a joint length of 8D, (b) is a graph showing the relationship between vertical load and vertical displacement due to the same repeated load, and (c) is a graph showing the relationship between the number of repeated loads and maximum crack width. [Figure 11] Graphs showing the results of the bending load test of the same specimen, where (a) is a graph showing the relationship between vertical load and vertical displacement for a joint length of 6D, (b) is a graph showing the relationship between vertical load and vertical displacement due to the same repeated load, and (c) is a graph showing the relationship between the number of repeated loads and the maximum crack width. DETAILED DESCRIPTION OF THE INVENTION

[0029] Next, an embodiment of a joining structure for a deck slab according to the present invention will be described based on the examples shown in Figures 1 to 11. In the figures, reference numeral 1 denotes a deck slab 1, and reference numerals 2 and 3 denote deck members that constitute the deck slab 1.

[0030] This deck 1 is composed of multiple deck members 2, 3 made of precast concrete that have been manufactured in advance in a factory or the like, and is constructed by arranging each deck member 2, 3 in the bridge axis direction on a steel girder 4 and joining each deck member 2, 3 that is adjacent in the bridge axis direction to each other.

[0031] In this embodiment, the bridge axis direction refers to the extension direction of the deck that constitutes an elevated road, bridge, etc., and the direction perpendicular to the bridge axis refers to the direction that is perpendicular to the bridge axis direction and parallel to the width direction of the deck that constitutes an elevated road, bridge, etc. Also, the deck thickness direction refers to the direction that is perpendicular to the bridge axis direction and perpendicular to the deck plane.

[0032] As shown in Figures 1 and 2, the joint structure of this deck slab 1 comprises a plurality of reinforcing bars 5, 5... that protrude in the bridge axis direction at intervals from the joint end faces of the opposing deck members 2, 3, respectively, and the reinforcing bars 5, 5... that protrude from the joint end face of one opposing deck member 2 are arranged between the reinforcing bars 5, 5... that protrude from the joint end face of the other deck member 3, and filler material 6 is filled between the opposing deck members 2, 3.

[0033] The deck members 2, 3 comprise a concrete deck body 7, reinforcing bars 5, 5... embedded inside the deck body 7 in the bridge axis direction, and prestressing steel members (not shown) arranged in either the bridge axis direction or a direction perpendicular to the bridge axis of the deck body 7, or both, with the prestressing steel members providing prestress in either the bridge axis direction, the direction perpendicular to the bridge axis, or both. Note that the reference numeral 8 in the figure denotes reinforcing bars embedded in the deck body 7 and arranged in the direction perpendicular to the bridge axis.

[0034] The reinforcing bars 5, 5 . . . are threaded reinforcing bars, deformed reinforcing bars, etc., and are embedded in the deck body 7 with their tips protruding from the joint end surface of the deck body 7.

[0035] The reinforcing bars 5, 5... are arranged in multiple upper and lower tiers (two upper and lower tiers in this embodiment), and are arranged so that the reinforcing bars 5, 5... are offset from each other by a pitch in the direction perpendicular to the bridge axis by the deck members 2, 3 that are joined to each other, so that the reinforcing bars 5, 5... that protrude in the bridge axis direction from the joint end face of one of the opposing deck members 2 in the upper and lower two tiers are arranged between the reinforcing bars 5, 5... that protrude in the bridge axis direction from the joint end face of the other deck member 3.

[0036] In other words, the ends of the reinforcing bars 5, 5... that protrude from the joint end surfaces of the deck slab members 2, 3 that are joined to each other are arranged with a predetermined gap (gap) between the reinforcing bars 5, 5... and are overlapped by a predetermined length in the longitudinal direction (joint length), so that the axial force acting on each reinforcing bar 5, 5... is transmitted via the filler material 6.

[0037] The protruding length of these reinforcing bars 5, 5 . . . is longer than the distance d between the joint end faces of both deck slab members 2, 3, so that the tip ends thereof can be accommodated within storage sections 12, 12 .

[0038] As shown in FIG. 5, the reinforcing bar 5 may have an expanded diameter bearing member 9 with a diameter larger than the diameter of the reinforcing bar fixed to the tip thereof.

[0039] The expanded diameter support member 9 uses a commonly used plate nut or circular anchor plate (EG anchor plate), etc., and is formed in a disk shape with a diameter larger than the diameter of the reinforcing bars 5, 5..., and is fixed to the tip of the reinforcing bars 5, 5... by screwing or welding.

[0040] Furthermore, as shown in Figure 6, the expansion support member 9 may be composed of multiple (a pair in this embodiment) nut-type members 10, 11 screwed onto the threaded portion 5a provided at least at the end of the reinforcing bar 5, in which case at least one of the multiple nut-type members 10, 11 (nut-type member 10 in this embodiment) can be tightened to another adjacent nut-type member (nut-type member 11 in this embodiment) to fix the reinforcing bar 5 in a predetermined position.

[0041] As shown in Figure 6, the position of the expanded diameter support member 9 is such that the corresponding expanded diameter support portions of adjacent reinforcing bars 5, 5... are arranged in the direction in which the support resistance force X acts (a direction forming a predetermined angle with the reinforcing bars 5), so that the expanded diameter support members 9 of adjacent reinforcing bars 5, 5... can support each other.

[0042] The deck body 7 is formed as a flat plate with a predetermined thickness, and has a plurality of storage sections 12, 12... recessed at intervals perpendicular to the bridge axis, which open to the opposing deck members 2, 3 to be joined to the joint ends at both ends in the bridge axis direction.

[0043] That is, at the joint end of the deck body 7, convex portions 13, 13... are formed between adjacent storage sections 12, 12... with the joint end surface as the apex, and the storage sections 12, 12... and the convex portions 13, 13... form an uneven shape in a plan view, and the ends of the reinforcing bars 5, 5... protrude approximately horizontally in the direction of the bridge axis from the apex of the convex portions 13, 13..., which are the joint end surfaces.

[0044] The storage sections 12, 12... are formed as concave grooves that open to the upper and lower surfaces of the deck members 2, 3 in a plan view, i.e., have an arc-shaped or semi-elliptical cross section parallel to the deck plane, and as shown in Figures 3 and 4, the reinforcing bars 5 protruding from the convex portions 13 that form the joint end surfaces of the deck members 2, 3 to be joined during the joining work can be stored in the storage sections 12, 12... without interfering with the joint end surfaces of the opposing deck members 3, 2.

[0045] Furthermore, the configuration of the storage sections 12, 12... is not limited to this embodiment, and for example, the cross section of the storage sections 12, 12... may be a bottomed groove shape with an open upper surface side of the deck members 2, 3 and a closed lower end side.

[0046] Furthermore, the positions of the storage sections 12, 12... are shifted perpendicular to the bridge axis by the pitch of the reinforcing bars 5, 5... due to the deck members 2, 3 that are joined to each other, so that the ends of the reinforcing bars 5, 5... protruding from the end faces of the convex sections 13, 13... overlap by the length of the joint and the tips of the reinforcing bars 5, 5... are contained within the storage sections 12, 12...

[0047] Furthermore, when each storage section 12, 12... is equipped with an expanded diameter support member 9 at the tip of the reinforcing bar 5, the distance from the joint end face to the apex in the bridge axial direction, specifically, the depth equal to the radius in the case of an arc-shaped section or the minor axis radius or major axis radius in the case of a semi-elliptical cross section, is set to be greater than the axial length of the expanded diameter support member 9, and the opening edge on the end face side (top surface of the convex portion 13) is positioned so as not to interfere with the support stress range of the expanded diameter support member 9.

[0048] Furthermore, as shown in Figures 2 and 4, the deck body 7 has a concave recess 14 for a shear resistance key formed between adjacent reinforcing bars 5, 5... in the deck thickness direction of the joint end surface, i.e., in the center of the deck thickness direction of the convex portion 13.

[0049] This recess 14 for the shear resistance key has a cross section parallel to the side surface of the deck slab that is arc-shaped or semi-elliptical when viewed from the side, and by filling this recess 14 for the shear resistance key with filler material 6, the shear resistance is increased.

[0050] Furthermore, the shape of the recess 14 for the shear resistance key is not limited to the above-mentioned arc-shaped or semi-elliptical shape, and for example, it may be formed as a recess whose cross section perpendicular to the bridge axis is trapezoidal or rectangular, and instead of the recess 14 for the shear resistance key, as shown in Figure 8(a), a convex portion 15 for the shear resistance key may be provided that protrudes from approximately the center of the deck thickness direction of the end face of the convex portions 13, 13..., or as shown in Figure 8(b), a recess 14 for the shear key may be provided on one of the opposing joint ends and a convex portion 15 for the shear key may be provided on the other.

[0051] The filling material 6 is, for example, a material containing special steel fibers and having high strength. 100~120N It is made of high-strength fiber-reinforced concrete or high-strength fiber-reinforced mortar, and has high tensile strength and toughness, making it possible to omit reinforcing steel bars perpendicular to the bridge axis between the joining deck members 2, 3. Note that high-strength fiber-reinforced concrete or high-strength fiber-reinforced mortar, or even stronger concrete or mortar, may also be used for the filler material 6.

[0052] Furthermore, the high-strength fiber reinforced concrete or high-strength fiber reinforced mortar is suitably filled into the storage sections 12, 12..., the shear-resisting key recesses 14, and the gaps between the reinforcing bars 5, 5...

[0053] The joint structure of the deck 1 configured in this manner stores the tips of the reinforcing bars 5, 5..., which do not contribute much to the adhesion strength with the filler material 6, in the storage sections 12, 12..., thereby narrowing the distance between the joint end faces of the joined deck members 2, 3, and making the joint length shorter (about 1 / 2 to 1 / 3) than that of a general lap joint.

[0054] Furthermore, in the joint structure of this deck slab 1, storage sections 12, 12... that are semicircular or semi-elliptical in plan view are provided at the joint ends, which increases the bonding area between the joint surface and the filler material, improves the adhesion between the filler material and the deck slab components, and also prevents stress concentration, thereby dispersing the occurrence of cracks when repeated loads are applied.

[0055] Furthermore, in the joint structure of this deck slab 1, by using concrete or mortar with a strength at least equal to that of high-strength fiber-reinforced concrete or high-strength fiber-reinforced mortar as the filler material 6, high tensile strength and high toughness can be obtained, and reinforcing steel bars oriented perpendicular to the bridge axis between the joined deck slab members 2, 3 can be omitted.

[0056] Furthermore, in this deck slab joint structure, by providing expanded diameter bearing members 9 at the ends of the reinforcing bars 5, 5..., in addition to increasing the bond strength between the reinforcing bars 5, 5... themselves (straight sections) and the filler 6, as shown in Figure 6, a bearing resistance force X acts on the compressive stress transmission area (compression strut) of the expanded diameter bearing members 9 attached to adjacent reinforcing bars 5, 5... in a specified direction (a direction forming a specified angle with the reinforcing bars 5, 5...), and the expanded diameter bearing members 9, 9 support each other, so the joint length can be reduced to about one-third of that of a general lap joint.

[0057] In this case, in the joining structure of this deck slab 1, the expanded diameter support member 9 is stored in the storage section 12, 12... formed at the joining end of the mating deck slab members 2, 3 to be joined, and the distance between the joining end faces of the joined deck members 2, 3 can be narrowed by that distance.

[0058] Next, the results of an experiment conducted to confirm the effects of the deck slab joint structure according to the present invention will be shown. Note that the same components as those in the above-mentioned embodiment will be assigned the same reference numerals and their explanations will be omitted.

[0059] The experiment involved subjecting the test specimens for each case shown in the table below to 10 repeated loads at the deck's operating load, followed by a monotonically increasing bending load test, and comparing the bending rigidity, bending strength, and crack width after cracking for each test specimen.

[0060] [Table 1] As a result, it was confirmed that for a joint length of 8D, the test specimens (Case 3-1, Case 3-3) equipped with a storage section 12 exhibited sufficient performance in terms of bending rigidity (inclination), bending strength (peak), and crack width (not increasing rapidly), regardless of whether or not an expanded diameter support member 9 was installed.

[0061] Furthermore, as shown in FIG. 10, it was confirmed that when the storage section 12 was provided (Case 3-3), the bending rigidity after cracking was superior compared to when the storage section 12 was not provided (Case 3-5).

[0062] Furthermore, in the case of a joint length of 6D, as shown in Figure 11, in the case where the reinforcing bar 5 does not have an expanded diameter support member 9 (Case 2-1), there are concerns about bending strength. However, in the case where an expanded diameter support member 9 consisting of a plate nut is provided at the end of the reinforcing bar 5 (Case 2-3), it was confirmed that sufficient performance was demonstrated in terms of bending rigidity, bending strength, and crack width, even when the distance between the joint end faces of the deck members 2 and 3 was 100 mm.

[0063] In the above-described examples, the filling material used is one having a strength equal to or greater than that of high-strength fiber-reinforced concrete or high-strength fiber-reinforced mortar, but ordinary concrete or mortar may also be used as the filling material. [Explanation of symbols]

[0064] 1 floor slab 2,3 Deck members 4 steel girder 5. Reinforced concrete 6 Filling material 7 Deck body 8 Horizontal Stripes 9 Expanded diameter bearing member 10,11 Nut-type member 12 Storage area 13 Convex part 14 Shear-resistant key recess 15 Shear resistance key protrusion

Claims

1. A deck formed by joining multiple deck members in the bridge axis direction, A deck joint structure in which a plurality of threaded reinforcing bars protrude at intervals from the joint end faces of opposing deck members in a direction perpendicular to the bridge axis, and the threaded reinforcing bars protruding from the joint end face of one opposing deck member are arranged between the threaded reinforcing bars protruding from the joint end face of the other deck member, and filler material is filled between the opposing deck members, At the joint ends of the opposing deck members, a storage section that opens to the other side and into which the tip end of the threaded reinforcing bar fits is recessed in the shape of a circular arc or semi-elliptical groove in a plan view, opening on the upper and / or lower surfaces of the deck members, A deck slab joint structure characterized in that the filler has a strength at least equal to or greater than that of high-strength fiber-reinforced concrete or high-strength fiber-reinforced mortar.

2. A deck slab joining structure as described in Claim 1, in which an expanded diameter support member having a diameter larger than the diameter of the rebar is fixed to the end of the screw-jointed rebar, and the expanded diameter support member is contained in the storage section.

3. 3. The deck slab joining structure according to claim 2, wherein the expanded diameter support member is composed of a plurality of nut-type members screwed onto threaded portions provided at the ends of at least the threaded reinforcing bars.

4. 4. The deck slab joining structure according to claim 2 or 3, wherein the storage section is arranged at a position where its end face side opening edge does not interfere with the bearing stress range of the expanded diameter bearing member.

5. A deck joint structure described in any one of claims 1 to 4, wherein the threaded reinforcing bars are arranged in multiple rows at intervals in the deck thickness direction, and a recess or protrusion for a shear resistance key is formed between adjacent threaded reinforcing bars in the deck thickness direction at the joint end face.

6. The deck slab joint structure according to claim 5, wherein the recess for the shear resistance key is arc-shaped or semi-elliptical in side view.

Images