JP2019127713A - Concrete member, joint, and method for connecting concrete member - Google Patents

Abstract

To provide a concrete member that can achieve weight saving by reducing thickness without changing the specifications of a joint.SOLUTION: A loop-shaped joint 20 is inclined with respect to a plane part 14 of a floor slab body 11 in lateral view by shifting an anchorage start point Zof a plane side straight part 22 and an anchorage start point Zof a bottom side straight part 23 toward the longitudinal direction of a side part 12 with respect to the floor slab body 11.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a concrete member provided with a looped joint, a looped joint provided to the concrete member, and a concrete member connecting method for connecting a concrete member provided with a looped joint It is.

  Conventionally, as a precast concrete floor slab erected on a main girder in a bridge or the like, for example, there is a concrete member described in Patent Document 1 below. The concrete member has a flat plate shape, and a loop-like reinforcing bar (hereinafter referred to as a "loop joint"), which is a joint, projects from the side toward the bridge axial direction (see FIG. 1).

  Further, for example, as in an elevated track described in Patent Document 2 listed below, there are also those in which a loop joint protrudes in the vertical direction from a columnar concrete member. That is, for example, as shown in FIG. 2, there is a case where the loop joint 220 protrudes from the upper part or the lower part of the column member 210.

  Also, for example, as shown in FIG. 3, the loop joint 320 may project from the side of the wall member 310.

  A joint structure is realized by overlapping the loop joints described above. For example, in the concrete member provided with the conventional loop joint shown in FIG. 1, FIG. 2 and FIG. 3, the thickness of the concrete member is determined by the shape of the loop joint.

Unexamined-Japanese-Patent No. 2002-227130 Unexamined-Japanese-Patent No. 2004-270150

  By the way, since the reinforced concrete floor slab (hereinafter referred to as "RC floor slab") of the old bridge in the construction year is designed based on the past standards, it may be thinner than the thickness prescribed by the current standards. In such a bridge, when the floor slab is renewed for repair or the like, if the thickness of the floor slab is designed according to the current standards, the thickness of the floor slab becomes thicker than the existing floor slab. If the renewed floor slab is thicker than the existing floor slab, the dead load will increase, and the existing steel girder and substructure will be burdened. Therefore, in the renewal construction of RC floor slabs, it is necessary to make the floor slabs lighter for renewal from the viewpoint of restriction by the load capacity of the existing steel girders and substructures and securing of the earthquake resistance of the bridge.

One way to reduce the weight of the RC floor slab is to replace it with a thin prestressed concrete floor slab (hereinafter referred to as “PC floor slab”). In the design of PC floor slabs using loop joints, the thickness of the PC floor slab is generally determined by the size of the loop joints. Here, a conventional loop joint will be described with reference to the drawings. FIG. 1 shows a conventional PC deck 110 and loop joint 120. In FIG. 1, the bending diameter of the loop joint 120 is determined by the thickness of the reinforcing bar, and the distance between the reinforcing bars facing each other in the thickness direction of the PC floor slab 110 by the bending diameter (hereinafter referred to as “rebar interval”) X Is determined. On the other hand, the minimum cover of the reinforcing bar of the concrete member is determined in accordance with the thickness of the reinforcing bar, the type of the concrete member, the environmental conditions in which the concrete member is placed, and the like. Therefore, the thickness of the PC floor slab 110 is defined by the reinforcing bar interval X, the fog to the reinforcing bar on the upper surface side of the PC floor slab 110 (hereinafter referred to as “top floor covering fog”) X ₁ , and the lower surface side of the PC floor slab head for reinforcement (hereinafter referred to as "floor layout paper side head".) obtained by the sum of X _2.

Thus, a design method is established for the PC floor slab 110 using the loop joint 120, and the thickness of the PC floor slab 110 depends on the specification of the loop joint 120. if the values of slab superior temporal X ₁ and floor layout paper side head X ₂ and the minimum value, it is possible to reduce the PC slab 110. However, in order to make the PC floor slab 110 thinner and lighter than that, it is necessary to change the specifications of the loop joint 120 to change the thickness and bending diameter of the reinforcing bar.

  The present invention has been proposed in view of the above situation. That is, weight reduction can be realized by reducing the thickness without changing the specification of the joint, and the tolerance of the arrangement of the joint can be expanded, and an area not occupied by the joint can be secured. An object of the present invention is to provide a concrete member that can effectively use this region, a joint that can reduce the weight of the concrete member, and a concrete member connection method that can appropriately connect the concrete member.

  In order to achieve the above object, the concrete member according to the present invention is a concrete member provided with a loop-like joint on the side of the concrete member main body, viewed from the side of the concrete member main body, and the joint is Further, it is inclined with respect to the flat portion of the concrete member main body.

  The concrete member according to the present invention is characterized in that the thickness of the concrete member body is determined by the degree of inclination of the joint.

  The joint according to the present invention is a loop-shaped joint provided on the side portion of the concrete member main body, and is inclined with respect to the flat portion of the concrete member main body as viewed from the side of the concrete member main body. It is characterized by

  A concrete member connection method according to the present invention is provided in a side portion of a concrete member main body, and is a loop shape that is inclined with respect to a flat portion of the concrete member main body as viewed from the side of the concrete member main body. It is a concrete member connection method which connects a concrete member which has a joint, One side of a guide member which is longer than thickness of the concrete member between the joints of the 1st concrete member which is the concrete member which is already installed Attaching the second concrete member which is the concrete member to be connected to the first concrete member, and making the joint of the second concrete member face the other part of the guide member; By bringing the member closer to the first concrete member, the second concrete Through a procedure for placing said fitting of said fitting and said first concrete member of members alternately, and wherein the.

  In the concrete member according to the present invention, the joint is inclined with respect to the flat portion of the concrete member body as viewed from the side of the concrete member body. That is, since the joint is inclined, the vertical width occupied by the joint becomes narrow in the thickness direction of the concrete member body, and the concrete member becomes thinner accordingly. On the other hand, the reinforcing bar interval of the joint is the same as when the joint is not inclined. Therefore, based on the conventional design method, weight reduction can be implement | achieved by making a concrete member thin, without changing the specification of a coupling. In addition, even when a joint having a large diameter is used, the vertical width occupied by the joint is narrowed in the thickness direction of the concrete member main body because the joint is inclined. Therefore, the diameter of the joint can be increased without changing the thickness of the concrete member, and the required load bearing capacity can be ensured. In addition, since the joint is inclined, a region not occupied by the joint is increased on the side surface, and this region can be used effectively.

  In the concrete member according to the present invention, the thickness of the concrete member body is determined by the degree of inclination of the joint. That is, the greater the degree of inclination, the thinner the concrete member. Therefore, weight reduction can be realized by thinning the concrete member.

  The joint according to the present invention is inclined with respect to the flat portion of the concrete member body as viewed from the side of the concrete member body. Therefore, weight reduction can be realized by thinning the concrete member without changing the specifications of the joint.

  The concrete member connecting method according to the present invention comprises: a procedure for attaching one portion of a guide member which is longer than the thickness of the concrete member between joints of the first concrete member which is an existing concrete member, and the first concrete member The procedure of making the joint of the second concrete member which is a concrete member to be connected to the other face the other part of the guide member, and bringing the second concrete member close to the first concrete member along the guide member And a procedure of alternately arranging the joints of the members and the joints of the first concrete member. That is, when the first concrete member and the second concrete member are connected by interposing the guide member, the contact between the first concrete member and the second concrete member, the joint of the first concrete member and the second concrete member Contact with the joint and contact between each concrete member and each joint are hindered. Therefore, it is possible to properly connect the concrete member while avoiding breakage.

The loop joint is expanded and shown in the conventional PC floor slab, (a) is a front transparent view of the PC floor slab, (b) is a side view of the PC floor slab. The column member provided with the conventional loop joint is shown, (a) is a perspective view, (b) is an AA sectional view of (c), (c) is a front view, (d) is a side view. . The wall member provided with the conventional loop joint is shown, (a) is a perspective view, (b) is a top view, (c) is a front view, (d) is AA sectional drawing of (c). . It is an appearance perspective view of a concrete member concerning a first embodiment of the present invention. The external appearance of the concrete member which concerns on 1st embodiment of this invention is shown, (a) is a top view, (b) is a side view, (c) is a front view. The joint of the concrete member according to the first embodiment of the present invention is shown enlarged. (A) (c) (e) is a front view of the concrete member, (b) (d) (f) is a concrete member Side view of FIG. It is an enlarged side view of the concrete member which concerns on the modification of 1st embodiment of this invention. A part of construction process of the concrete member concerning a first embodiment of the present invention is shown, and (a) and (b) are construction process explanatory views in case a concrete member is made a floor slab. It is construction process explanatory drawing in which a part of construction process of the floor slab by the concrete member connection method which concerns on 1st embodiment of this invention was shown. It is construction process explanatory drawing in which a part of construction process of the floor slab by the concrete member connection method which concerns on 1st embodiment of this invention was shown. The joint is expanded and shown in the state where the concrete member concerning a first embodiment of the present invention was connected, and (a) (c) (e) is a front transparent view of a concrete member, (b) (d) ( f) is a side view of the concrete member as viewed from the filling portion. The appearance of a concrete member according to a second embodiment of the present invention is shown, (a) is a perspective view, (b) is a plan view, (c) is a front view, and (d) is an AA cross section of (c). FIG. The external appearance of the concrete member which concerns on 3rd embodiment of this invention is shown, (a) is a perspective view, (b) is AA sectional drawing of (c), (c) is a front view, (d) is a side view FIG.

  Below, the concrete member concerning the first embodiment of the present invention, a joint, and the concrete member connection method are explained based on a drawing. 4 and 5 show the appearance of the floor slab 10 as a concrete member. In the following description, assuming that it is used for a bridge, the bridge axial direction is a side. The direction perpendicular to the bridge axis is the longitudinal direction and the front or back. The vertical direction is the upper and lower sides in the thickness direction, the upper surface is the plane, and the lower surface is the bottom. Moreover, although a floor slab is demonstrated as an example of a concrete member below, the concrete member of this invention is not limited to a floor slab, The block-shaped precast concrete general is included in general. In addition, since the cast-in-place concrete and precast concrete may be joined, the concrete member includes the cast-in-place concrete in this case.

  The floor slab 10 is precast concrete, and as shown in FIGS. 4 and 5, a plurality of joints 20 are attached to both sides 12 of the floor slab main body 11 formed in a substantially rectangular flat plate shape. . As shown in FIG. 5C, the side portions 12 of the floor slab main body 11 are inclined in the thickness direction, and protrude sideward as it goes downward. The both side portions 12 may be straight without being inclined in the thickness direction. Moreover, the lower part of the floor slab main body 11 protrudes toward both sides rather than the side part 12, and what is called a jaw part may be formed.

As shown in FIGS. 4 and 5, the joint 20 has a loop shape and is arranged in the longitudinal direction of the floor slab body 11. More specifically, the joint 20 is a U-shaped reinforcing bar, and straight plane-side straight portions 22 and bottom-side straight portions 23 extend in parallel from both ends of the curved curved portion 21. A part of both the straight portions 22 and 23 is embedded and fixed in the floor slab body 11. As shown in FIG. 5 (b), the joint 20, and a fixing start part _{Z 23} of the fixing starting portion _{Z 22} and the bottom side straight portion 23 of the flat side straight portion 22 with respect to the floor plate body 11, the side 12 The joint 20 is inclined with respect to the flat surface portion 14 (or the bottom surface portion 15) of the floor slab body 11 when viewed from the side. In other words, as shown in FIG. 4, when a surface including the curved portion 21 and both straight portions 22 and 23 is an imaginary surface V in an arbitrary joint 20, the imaginary surface V and the planar portion 14 are included. And intersect. The angles θ ₁ and θ ₂ formed by the virtual surface V and the flat portion 14 are not right angles but are obtuse or acute angles. Therefore, as shown in FIG. 5A, in the joint 20, the bottom-side straight portion 23 is visible in a plan view.

  In the floor slab 10 configured as described above, the thickness of the floor slab body 11 is determined by the degree of inclination of the joint 20. Here, the relationship between the thickness of the floor slab main body 11 and the degree of inclination of the joint 20 will be described based on the drawings. FIG. 6 is an enlarged view of the joint 20 in various floor slabs 10 with different degrees of inclination of the joint 20.

  As shown in FIG. 6, in the joint 20, the diameter of a circle inscribed in the bending portion 21 (hereinafter referred to as “inscribed circle diameter”) is D. In accordance with the degree of inclination of the joint 20, the projected reinforcing bar interval Y (excluding the thickness of the reinforcing bar) projected in the longitudinal direction increases or decreases, and thereby the thickness of the floor slab 10 is determined. As shown in FIGS. 6A and 6B, for example, when the degree of inclination is 75 degrees, the projected reinforcing bar interval Y when the inscribed circle diameter D is 1 is about 0.96, It is smaller than the inscribed circle diameter D. The thickness of the reinforcing bar, the thickness of the upper side of the floor slab and the thickness of the lower side of the floor slab are added to the projected reinforcing bar interval Y, and the thickness T of the floor slab 10 is about compared with the case where the joint 20 is not inclined. 2% thinner.

  As shown in FIGS. 6C and 6D, for example, when the degree of inclination is 60 degrees, the projected reinforcing bar interval Y when the inscribed circle diameter D is 1 is about 0.84, It is smaller than the inscribed circle diameter D. The thickness of the reinforcing bar, the thickness of the upper side of the floor slab and the thickness of the lower side of the floor slab are added to the projected reinforcing bar interval Y, and the thickness T of the floor slab 10 is about compared with the case where the joint 20 is not inclined. 8% thinner.

  As shown in FIGS. 6E and 6F, for example, when the degree of inclination is 45 degrees, the projected reinforcing bar interval Y when the inscribed circle diameter D is 1 is about 0.66, It is smaller than the inscribed circle diameter D. The thickness of the reinforcing bar, the thickness of the upper side of the floor slab and the thickness of the lower side of the floor slab are added to the projected reinforcing bar interval Y, and the thickness T of the floor slab 10 is about compared with the case where the joint 20 is not inclined. 17% thinner.

  As described above, as the degree of inclination of the joint 20 increases, the floor slab body 11 is formed thinner. When the degree of inclination of the joint 20 increases, the floor slab body 11 forms a non-occupied region that is not occupied by the joint 20 in the side portion 12. Here, the non-occupied area will be described based on the drawings. FIG. 7 shows unoccupied areas.

  As shown in FIG. 7, when the joint 20 is inclined, the side portion 12 is spaced from the longitudinal end of the floor slab body 11 and the joint 20 at the extreme end in the longitudinal direction. The unoccupied region 13 that is a region not occupied by the joint 20 is formed. In the unoccupied region 13, for example, a reinforcing bar 16 is arranged. The width of the unoccupied region 13 changes according to the degree of inclination. 7 (a) corresponds to the floor slab 10 of FIG. 6 (c) (d), and FIG. 7 (b) corresponds to the floor plank 10 of FIG. 6 (e) (f).

  Next, as a concrete member connection method of the present embodiment, a floor slab erection method in the case of laying the floor slab 10 will be described with reference to the drawings. 8 to 11 show the construction process by the floor slab erection method.

  As shown in FIG. 8, the floor slab 10 is installed on the main beam 1 and arranged in the bridge axis direction. There are various methods for bringing the second floor slab 10 b connected to the first floor slab 10 a closer to the first floor slab 10 a already installed on the main girder 1. For example, as shown in FIG. 8A, after the second floor slab 10b is placed on the main girder 1, the second floor slab 10b is slid along the main girder 1 in the bridge axial direction, There is a method of bringing it close to the first floor slab 10a. On the other hand, as shown in FIG. 8B, when the second floor slab 10b is floated and the second floor slab 10b is lowered, there is a method of overlapping the joint 20b on the joint 20a of the first floor slab 10a. . However, in any method, when the floor slabs 10a and 10b, the joints 20a and 20b, and the floor slabs 10a and 10b contact the joints 20a and 20b, the floor slab main body 11 or the joints 20a and 20b may be damaged.

  Therefore, in the floor slab installation method, a plate member 30 as a guide member is used as shown in FIG. The plate member 30 has a substantially rectangular shape, is longer than the thickness of the floor slabs 10a and 10b, is thinner than the distance between the joints 20a and 20b, and is shorter than the length of the joints 20a and 20b. The plate member 30 has a lower part 32 as one part below the half and an upper part 31 as the other part above the half. The plate-like member 30 is made of a material having little friction and little resistance due to contact with the joints 20a and 20b, or such a process is performed. The guide member is not limited to a rectangle, for example, A shape formed by rounding corners of a rectangle to form a round shape, an oval shape, an oval shape, or the like may be used.

  First, the lower part 32 of the plate member 30 is attached between the joints 20a of the first floor slab 10a, and the plate member 30 is leaned against the joint 20a. Next, the upper portion 31 of the plate member 30 is attached between the joints 20b of the second floor plate 10b by causing the joint 20b of the second floor plate 10b in a floating state to face the upper portion 31 of the plate member 30. . In this state, the joint 20a of the first floor plate 10a is in contact with the back side of the plate member 30, and the joint 20b of the second floor plate 10b is in contact with the front side of the plate member 30. Finally, the second floor slab 10 b is lowered along the plate member 30. At that time, since the joints 20a and 20b of the floor slabs 10a and 10b separate the plate member 30, contact is prevented. As shown in FIG. 10, the second floor slab 10b is arranged horizontally to the first floor slab 10a, and the joints 20b of the second floor slab 10b and the joints 20a of the first floor slab 10a are alternately arranged. Be done. In addition, the plate member 30 is removed after construction.

As shown in FIG. 11, in a state where the joints 20a and 20b of the floor slabs 10a and 10b are overlapped, a plurality of main bars 2 are arranged orthogonally to the joints 20a and 20b. By placing the concrete 4 in the space filling portion 3, the floor slabs 10a and 10b are connected to each other through the joints 20a and 20b. The thinner the floor slabs 10a and 10b, the smaller the amount of concrete 4 to be cast. In FIG. 11, the degree of inclination of the joints 20a and 20b is represented by the angle between the main bar 2 and the joint 20a, but since the main bars 2 are generally arranged horizontally, FIGS. 4 and 5 can be obtained. It does not differ from the formed angles θ ₁ and θ ₂ shown in (b). Accordingly, the floor slabs 10a and 10b shown in FIG. 11 are the same as the floor slab 10 shown in FIG.

  As described above, the floor slab 10 and the joint 20 are configured, and a floor slab erection method using the floor slab 10 is realized. Next, the effects of the present embodiment will be described.

According to this embodiment, the joint 20 includes a fixing starting portion Z ₂₃ of the fixing starting portion Z ₂₂ and the bottom side straight portion 23 of the flat side straight portion 22 with respect to the floor plate body 11, longitudinally oriented sides 12 The joint 20 is inclined with respect to the flat surface portion 14 (or the bottom surface portion 15) of the floor slab body 11 as viewed from the side (see FIG. 5B). That is, since the joint 20 is inclined, the projected reinforcing bar interval Y occupied by the joint 20 in the thickness direction of the floor slab body 11 is narrower than the inscribed circle diameter D (see FIG. 6). The floor slab 10 becomes thinner. On the other hand, the reinforcing bar interval of the joint 20 is the same as when the joint 20 is not inclined. Therefore, weight reduction can be realized by thinning the floor slab 10 without changing the specification of the joint 20 based on the conventional design method. Further, even when the joint 20 having a large diameter is used, the vertical width occupied by the joint 20 is reduced in the thickness direction of the floor slab body 11 because the joint 20 is inclined. Therefore, the diameter of the joint 20 can be increased without changing the thickness of the floor slab body 11, and a required load bearing capacity can be ensured. Furthermore, the tolerance | permissible_range of arrangement | positioning of the coupling 20 can be expanded.

  According to the present embodiment, the thickness of the floor slab main body 11 is determined by the degree of inclination of the joint 20. That is, as the degree of inclination of the joint 20 increases, the floor slab main body 11 is formed thinner. Therefore, weight reduction can be realized by making the floor slab 10 thin. For example, the thickness of the joint 20 is "D22" and the degree of inclination is 55, as compared with the case where the size of the joint 20 is "D19" and the degree of inclination is 90 degrees. When the angle is between 57 degrees and 57 degrees, the thickness of the floor slab body 11 is the same. That is, the joint 20 can be thickened without changing the thickness of the floor slab.

  According to the present embodiment, with the degree of inclination of the joint 20 being increased, the side portion 12 is opened between the longitudinal end of the floor slab body 11 and the longitudinal end 20 of the joint. An unoccupied region 13 which is a region not occupied by the joint 20 is formed (see FIG. 7). Therefore, for example, the reinforcing bars 16 can be arranged in the unoccupied region 13.

  According to the present embodiment, the lower portion 32 of the plate member 30 is attached between the joints 20a of the first floor slab 10a, and the plate member 30 is erected on the joint 20a. Next, the upper portion 31 of the plate member 30 is attached between the joints 20b of the second floor plate 10b by causing the joint 20b of the second floor plate 10b in a floating state to face the upper portion 31 of the plate member 30. . Finally, the second floor slab 10 b is lowered along the plate member 30. At that time, since the joints 20a and 20b of the floor slabs 10a and 10b separate the plate member 30, contact is prevented. Therefore, the floor slab 10 can be appropriately installed while avoiding breakage. In addition, the thinner the floor slabs 10a and 10b, the smaller the amount of concrete 4 to be placed in the padding portion 3.

  The present invention may have a configuration in which the joint 41 projects from the side surface portion of the wall member 40 as the concrete member and the joint according to the second embodiment shown in FIG. 12. In addition, since the structure of the wall member 40 and the coupling 41 is the same as that of 1st embodiment, description is abbreviate | omitted.

  In the connection method of the second embodiment, the plate-like member 30 is used as in the first embodiment. In this case, one side of the plate-like member 30 on the front side or the rear side of the half is one part, and the other is the other part. In addition, since the connection method is the same as that of 1st embodiment, description is abbreviate | omitted.

  The present invention may have a configuration in which the joint 51 projects from the upper or lower portion of the column member 50 as the concrete member and the joint according to the third embodiment shown in FIG. In addition, since the structure of the column member 50 and the coupling 51 is the same as that of 1st embodiment, description is abbreviate | omitted.

  In the connection method of the third embodiment, the plate-like member 30 is used as in the first embodiment. The configuration of the plate member 30 is the same as that of the second embodiment. In addition, since the connection method is the same as that of 1st embodiment, description is abbreviate | omitted.

  The second embodiment and the third embodiment also have the same effects as the first embodiment.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited to the said embodiment. And, in the present invention, various design changes can be made without departing from the matters described in the claims.

1 Main Girder 2 Main Reinforcement 3 Spacing Section 4 Concrete 10 Floor Slab (Concrete Member)
10a First floor slab (first concrete member)
10b Second floor slab (second concrete member)
11 Floor slab body (concrete member body)
DESCRIPTION OF SYMBOLS 12 Side part 13 Unoccupied area | region 14 Plane part 15 Bottom face part 16 Reinforcement 20, 20a, 20b Joint 21 Curved part 22 Plane side linear part 23 Bottom face side linear part 30 Plate member (guide member)
31 Upper part 32 Lower part 40 Wall member (concrete member)
41, 51 Joint 50 Column member (concrete member)
DESCRIPTION OF SYMBOLS 110 PC floor plate 120, 220, 320 Loop joint 210 Column member 310 Wall member D Inscribed circle diameter T Thickness V Virtual surface X Rebar interval X ₁ Floor version upper side fog X ₂ floor version lower side fog Y Projected reinforcing bar interval Z ₂₂ , Z ₂₃ fixing starting point angle formed by θ ₁ and θ ₂

Claims (4)

In a concrete member provided with a looped joint on the side of the concrete member body,
When viewed from the side of the concrete member body, the joint is inclined with respect to a flat portion of the concrete member body,
A concrete member characterized by that. The thickness of the concrete member body is determined by the degree of inclination of the joint,
The concrete member according to claim 1. In the loop joint provided on the side of the concrete member body,
As seen from the side of the concrete member body, it is inclined with respect to the flat portion of the concrete member body.
A joint characterized by that. A concrete member that is provided at a side portion of the concrete member main body and that connects a concrete member having a loop-shaped joint that is inclined with respect to a plane portion of the concrete member main body as viewed from the side of the concrete member main body. A connection method,
Between the joints of the first concrete member that is the existing concrete member, a procedure for attaching one part of the guide member that is longer than the thickness of the concrete member;
A step of causing the joint of the second concrete member, which is the concrete member to be connected to the first concrete member, to face the other portion of the guide member;
A step of alternately arranging the joint of the second concrete member and the joint of the first concrete member by bringing the second concrete member close to the first concrete member along the guide member; Pass,
A method for connecting concrete members.

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