JP6538606B2 - Construction method of floor slab and joint structure of PCa floor slab - Google Patents

Description

  The present invention relates to a method of constructing a floor slab formed by joining a pair of PCa floor slabs (precast concrete floor slabs) arranged adjacent to each other with a joint structure made of cast-in-place concrete, and a joint structure of PCa floor slabs About.

  As a floor slab of a bridge, there is one which is constructed by closely arranging a plurality of PCa floor slabs on a bridge girder so as to be aligned in the bridge axial direction, and unifying mutually adjacent PCa floor slabs. An RC loop joint is widely used as a joint structure of such a PCa floor slab (see FIGS. 15 and 16 of Patent Document 1). A PCa floor slab using RC loop joints is arranged such that a plurality of looped reinforcing bars are spaced apart in a direction perpendicular to the bridge axis and extend from the joint end face of the floor slab main body, and the looped reinforcing bars are embedded. It is formed by placing concrete. The looped rebar is curved in a circular arc in the thickness direction of the PCa floor slab, and is formed in an extension dimension overlapping with the looped rebars of the PCa floor slab arranged closely. A reinforcing bar extending in a direction perpendicular to the bridge axis is disposed inside the closed cross-sectional shape formed by the looped reinforcing bars of a pair of PCa floor slabs arranged close to each other, and in this state, the floor slabs of both PCa floor slabs An RC loop joint is constructed by placing concrete between the main bodies.

  However, in this RC loop joint, reinforcement rebars can not be arranged in advance inside the loop-like rebar before arranging the PCa floor slab, and after arranging a pair of PCa floor slabs in a predetermined position, a loop is formed. Reinforcement must be inserted inside the rebar. Therefore, the construction was complicated. Therefore, in the precast floor slab described in Patent Document 1, the loop-like reinforcing bars protruding from the floor slab main body in the bridge axis direction are replaced with upper joint reinforcing bars and lower joint reinforcing bars each having an end band (fixing portion) at the tip A floor slab body in which these joint reinforcing bars are arranged at intervals in the vertical direction and in a direction perpendicular to the bridge axis, and the upper end face of the floor slab main body serving as the projecting proximal end of the upper joint reinforcing bar becomes the projecting proximal end portion of the lower joint reinforcing bar The temporary placement accommodation groove for reinforcement bars is formed by making it dent than the lower end face of (refer to patent documents 1).

  In addition, the locking part (fixing part) protruding from the tip of the upper joint reinforcing bar is formed in a substantially half disk shape so that the upper surface is substantially flush with the upper surface of the upper joint reinforcing bar, and from the front end of the lower joint reinforcing bar There is also known a joint structure in which a protruding locking portion (fixing portion) is formed in a substantially half disk shape so that the lower surface thereof is substantially flush with the lower surface of the lower joint reinforcing bar (see Patent Document 2). In this joint structure, since the locking portion does not protrude to the concrete surface side, it is not necessary to increase the thickness of the joint portion or the PCa floor slab in order to secure the fogging of the concrete.

JP 2012-62664 A Patent No. 5700608 gazette

  However, when the precast floor slab using the joint structure of Patent Document 1 is erected, two precast floor slabs are disposed at predetermined positions adjacent to each other, and then temporarily placed in the precast temporary placement accommodation groove in advance. The reinforced reinforcing bars must be expanded between the upper joint reinforcing bars and the lower joint reinforcing bars, re-bonded to the upper joint reinforcing bars or the lower joint reinforcing bars after being placed at predetermined positions. Therefore, the placement and the binding operation of reinforcing bars at the site (that is, the placement operation) is required, and the operation is complicated.

  Further, in the joint structure of Patent Document 2, although the reinforcing rebar is not disposed at the joint portion, in the case where the reinforcing rebar is disposed between the upper joint reinforcing bar and the lower joint reinforcing bar, Patent Document 1 is a problem conventionally As in the case of the RC loop joint, after arranging a pair of PCa floor slabs in a predetermined position, reinforcement work must be performed by inserting reinforcing bars between the upper joint reinforcing bars and the lower joint reinforcing bars.

  The present invention, in view of such background, when joining a pair of PCa floor slabs arranged adjacent to each other by a joint structure, the reinforcing bar arranged between the upper joint reinforcing bar and the lower joint reinforcing bar It is an object of the present invention to provide a floor plate construction method capable of reducing on-site arrangement, binding work, and a joint structure of PCa floor plate.

  In order to solve the above problems, one aspect of the present invention is a floor slab formed by joining a pair of PCa floor slabs (8) arranged adjacent to each other by a joint structure (10) made of cast-in-place concrete. In the construction method of (4), the upper joint rebar (21U, 22U) and the lower joint rebar (21L, 22L) having the fixing portion (23) at the tip end are the upper (12U) and lower part (12U) of the joint end face (12) 12 (a step of preparing a plurality of PCa floor slabs extending from 12L) (FIG. 6, FIG. 8), and disposed under the overlapping portion of the upper joint reinforcing bars (21U, 22U) of the pair of PCa floor slabs Binding the upper reinforcement bar (25) to the upper joint bar of at least one of the PCa floor slabs (FIG. 6, FIG. 8), and the lower joint rebar (21 L) of the pair of PCa floor slabs , 22L) above the overlap of each other Bonding the lower reinforcement bar (26) to be bonded to the lower joint rebar of at least one of the PCa floor slabs (FIG. 6, FIG. 8), and arranging ahead of the pair of PCa floor slabs Placing the first PCa floor slab (8A) to be placed in a predetermined first position (P1) (FIG. 7 (A), FIG. 9 (A)); The second PCa floor plate (8B) to be arranged is at a position farther from the first PCa floor plate in plan view than the predetermined second position (P2) where the second PCa floor plate is to be arranged Step of suspending the lower joint reinforcing bar (22L) of the plate to a predetermined height at which the lower joint reinforcing bar (22L) of the first PCa floor plate is lower than the upper joint reinforcing bar (21U) (FIG. 7 (B), FIG. 9 (B)); 2) Move the PCa floor slab sideways to the first PCa floor slab side at the predetermined height The steps of disposing in the second position (FIGS. 7C to 7D and 9C), the first PCa floor slab disposed in the first position, and the disposing in the second position Concrete is placed between the second PCa floor slab (G) and the step of joining the first PCa floor slab and the second PCa floor slab together (FIG. 7 (E), FIG. 9 (D)) I assume.

  According to this aspect, the upper reinforcement bar disposed below the overlapping portion of the upper joint reinforcing bars is bound in advance to the upper joint reinforcing bar of at least one PCa floor plate, and is arranged above the overlapping portion of the lower joint reinforcing bars Since the lower reinforcing bars are pre-bonded to the lower joint reinforcing bars of at least one PCa floor plate, the location and bonding work of reinforcing bars in the field can be reduced. Although reinforcement bars are prearranged in advance, the operation of arranging a pair of PCa decks arranged adjacent to each other at a predetermined position is a second PCa deck that is arranged later at a predetermined height and the first PCa By moving it to the floor slab side, it is possible to prevent the reinforcing bars from interfering with each other. In the present specification, “interference” (or “does not interfere”) does not mean that reinforcing bars are in contact with each other (or do not contact) due to deflection of reinforcing bars, etc. 2PCa It means that it is in a relative positional relationship (or not in a relative positional relationship) that hinders the movement of the floor slab.

  Further, in the above aspect, in the step of preparing the PCa floor slab (FIG. 6), the fixing portion (23) is formed in a shape projecting in the horizontal direction only.

  According to this aspect, since the fixing unit does not project upward or downward with respect to the joint rebar provided with itself, when laterally moving the second PCa floor slab arranged later to the first PCa floor slab side at a predetermined height In addition, it is possible to prevent the fixing portion from interfering with the reinforcing rebar bound to the other PCa floor slab.

  In the above aspect, in the step of binding the upper reinforcing bar (25) (FIG. 6), the upper joint reinforcing bar (22U) of the first PCa floor slab (8A) of all the upper reinforcing bars (25) And in the step of binding the lower reinforcement bar (26), all lower reinforcement bars (26) are bundled with the lower joint rebar (21L) of the second PCa floor plate (8B), and the second PCa floor In the step of hanging down the plate (8B) (FIG. 7 (B)), the lower reinforcement bar (26) does not overlap the upper reinforcement bar (25) in the height direction, and the second PCa floor plate (8B) The step of suspending the second PCa floor slab to a height at which the second PCa floats and disposing the second PCa floor slab at the second position (P2) (FIG. 7 (C) to (D)) floats the second PCa floor slab. Move the second PCa floor slab sideways Wherein the step (FIG. 7 (C)) be disposed above the second position, a structure including the second in the upper position down hanging the first 2PCa deck step (FIG. 7 (D)).

  According to this aspect, since the second PCa floor slab is horizontally moved in the floating state, the second PCa floor slab can be easily arranged.

  In the above aspect, in the step of hanging down the second PCa floor slab (8B) (FIG. 9B), the second PCa floor slab is suspended to the same height as the second position (P2), and In the step of disposing the 2PCa floor slab at the second position (FIG. 9C), the second PCa floor slab is slid and moved laterally.

  According to this aspect, the second PCa floor slab can be laterally moved and disposed at the second position regardless of which PCa floor slab the reinforcing reinforcing bars are arranged in advance.

  Furthermore, in order to solve the above problems, another aspect of the present invention is a joint structure (10) of a PCa floor slab (8), which extends in a direction perpendicular to the bridge axis in the first PCa floor slab (8A) A plurality of first upper joint rebars (21U) are spaced apart in the direction perpendicular to the bridge axis so as to extend from the upper and lower portions of the first joint end face (12A), and each have a fixing portion (23) at the tip And a plurality of first lower joint rebars (21L) and the first joint end face of the second PCa floor slab (8B) disposed close to the first PCa floor slab with a gap (G) in the bridge axial direction. The spacers are arranged at intervals in a direction perpendicular to the bridge axis so as to extend from the upper and lower portions of the opposing second bonding end surface (12B), and each has a fixing portion (23) at its tip, and the corresponding first Extension length overlapping the upper joint rebar or the first lower joint rebar Below the overlapping portions of the plurality of second upper joint rebars (22U) and the plurality of second lower joint rebars (22L) and the first upper joint rebar (21U) and the second upper joint rebar (22U) Above the overlapping portion of the upper reinforcement bar (25) extending in a direction perpendicular to the bridge axis, and the overlapping portions of the first lower joint bar (21L) and the second lower joint bar (22L) Extending lower reinforcement bar (26), first upper joint bar (21U), first lower joint bar (21L), second upper joint bar (22U), second lower joint bar (22L) A joint concrete (13) constructed in the gap so as to entrap the upper reinforcement bar (25) and the lower reinforcement bar (26), and the fixing portion is formed in a shape projecting only in the horizontal direction Configuration.

  According to this aspect, since the fixing portion does not project upward or downward with respect to the joint rebar provided with itself, even if the reinforcing rebar is arranged at a predetermined position (on one of the PCa slabs) A pair of adjacent PCa deck slabs can be positioned at a predetermined position by laterally moving the PCa deck slab, which is disposed later with respect to the PCa deck slab previously disposed at the predetermined position. Therefore, the reinforcing bar can be bound in advance to at least one joint reinforcing bar, and the arrangement of reinforcing bars at the site and the bonding operation can be reduced.

  Thus, according to the present invention, when joining a pair of PCa floor slabs disposed adjacent to each other with a joint structure, it is possible at the site of reinforcement bars disposed between the upper joint rebar and the lower joint rebar. It is possible to provide a floor plate construction method capable of reducing the arrangement of bindings, and the joint structure of PCa floor plate.

The schematic perspective view which shows the assembly state of the PCa floor slab which concerns on embodiment Longitudinal section of joint structure of PCa floor slab according to the embodiment III-III sectional view in FIG. 2 IV-IV sectional view in FIG. 2 Head bar (A) side surface shown in FIG. 2, (B) flat surface, (C) front view (A) Top view of PCa floor version according to the first embodiment, (B) Side view Explanatory drawing of the construction procedure of the floor edition according to the first embodiment (A) Top view of PCa floor version according to the second embodiment, (B) Side view Explanatory drawing of the construction procedure of the floor edition which concerns on 2nd Example

  Hereinafter, with reference to the drawings, a method of constructing the floor slab 4 using the joint structure 10 of the PCa floor slab 8 and the PCa floor slab 8 according to the embodiment of the present invention will be described in detail.

  FIG. 1 is a schematic perspective view showing an assembled state of a bridge 1 to which a joint structure 10 of a PCa floor slab 8 according to the embodiment is applied. As illustrated, the bridge 1 includes a pair of bridge piers 2 (only one bridge pier 2 is shown in the drawing) spaced apart in the bridge axial direction, and a bridge girder 3 bridged between the pair of bridge piers 2. , And the floor plate 4 constructed on the bridge girder 3. The bridge 1 may be used as a road bridge and may be used for other purposes. One or both of the pair of bridge piers 2 may be abutments. The bridge girder 3 is arranged on the bridge pier 2 via a bearing 5. In the present embodiment, the bridge girder 3 is configured by three parallel parallel girder 6 extending in the bridge axial direction and a not-shown inclined structure connecting the girder 6 adjacent to each other in the bridge axial direction. .

  The floor slab 4 is constructed using a plurality of PCa floor slabs 8 each constituting a floor slab portion divided in the bridge axis direction. Specifically, the floor slab 4 sequentially arranges a plurality of PCa floor slabs 8 in the bridge axial direction with a gap G between them, sequentially constructing a joint structure 10 between a pair of PCa floor slabs 8 adjacent to each other. It is constructed by connecting a plurality of PCa floor versions 8. All illustrated PCa floor slabs 8 have the same shape. The PCa floor slab 8 of different shape or size may be used at the start end and the end of the bridge girder 3 and joints. Although illustration is omitted, on the upper surface of the bridge girder 3, studs for fixing floor slabs are implanted. On the other hand, fixing holes 9 for fixing the PCa floor slab 8 to the bridge girder 3 are formed at positions corresponding to the studs of the PCa floor slab 8 by receiving the studs and filling the filling material in that state. There is.

  FIG. 2 shows a longitudinal cross section around the joint structure 10 of the PCa floor slab 8 as seen through concrete. As shown in FIG. 1 and FIG. 2, the PCa floor slab 8 (8A, 8B) includes a reinforced concrete floor slab main body portion 11. The floor slab main body 11 is in the form of a plate having a generally rectangular shape that is long in the direction perpendicular to the bridge axis in plan view. One end face and the other end face of the floor slab main body 11 in the bridge axis direction become joint end faces 12 (12A, 12B) with the PCa floor slab 8 disposed close to each other in the bridge axis direction. Hereinafter, the PCa floor slab 8 located on the left side in FIG. 2 and previously disposed at a predetermined position on the bridge girder 3 is referred to as the first PCa floor slab 8A, and is located on the right side in FIG. The PCa floor slab 8 arranged at a predetermined position on the bridge girder 3 adjacent to 8A will be referred to as a second PCa floor slab 8B. When the two are not distinguished, they are simply referred to as the PCa floor plate 8. The end face on the second PCa floor plan 8B side (right side in FIG. 2) of the first PCa floor plan 8A disposed first is referred to as the first bonding end face 12A, and the first PCa of the second PCa floor plan 8B disposed later The end face on the floor slab 8A side (left side in FIG. 2) is referred to as a second bonding end face 12B. When the two are not distinguished from each other, they are simply referred to as bonding end faces 12.

  As shown in FIG. 2, the joint end face 12 of the PCa floor slab 8 extends in the direction perpendicular to the bridge axis, and extends substantially vertically in the direction of the bridge axis with respect to the joint surface lower portion 12L and the joint surface lower portion 12L. The bonding surface upper portion 12U extends substantially vertically at the recessed position, and the bonding surface lower portion 12L and the bonding surface upper portion 12U are connected, and the bonding surface middle portion 12M extends obliquely. Thereby, the gap G (FIG. 1) between the first joint end face 12A of the first PCa floor slab 8A and the second joint end face 12B of the second PCa floor slab 8B arranged at the predetermined position is wider at the upper part than at the lower part. It has become. Concrete is cast in this gap G and hardened to form joint concrete 13.

  The PCa floor slab 8 includes a plurality of first upper joint reinforcing bars 21U and a plurality of first lower joint reinforcing bars 21L integrally provided on the floor slab main body 11 so as to extend from the first joint end surface 12A, and a second joint. A plurality of second upper joint reinforcing bars 22U and a plurality of second lower joint reinforcing bars 22L integrally provided on the floor slab main body 11 so as to extend from the end face 12B are provided. Hereinafter, the first upper joint reinforcing bar 21U and the first lower joint reinforcing bar 21L are collectively referred to as a first joint reinforcing bar 21, the second upper joint reinforcing bar 22U and the second lower joint reinforcing bar 22L are combined, and the second joint reinforcing bar 22 The first joint rebar 21 and the second joint rebar 22 are collectively referred to as joint rebars 21 and 22. The joint rebars 21 and 22 extend in the bridge axial direction. A fixing portion 23 protruding in the radial direction from the tip is integrally provided on all joint reinforcing bars 21 and 22. Details of the fixing unit 23 will be described later.

  The first upper joint rebar 21U extends from the joint surface upper portion 12U of the first joint end surface 12A, and is disposed at a predetermined interval in the direction perpendicular to the bridge axis. The first lower joint rebar 21L extends from the lower joint surface 12L of the first joint end face 12A, and has the same position in the direction perpendicular to the bridge axis with the first upper joint rebar 21U at a predetermined distance in the direction perpendicular to the bridge axis. Is located in The second upper joint rebar 22U extends from the joint surface upper portion 12U of the second joint end surface 12B, and is disposed at a predetermined interval in the direction perpendicular to the bridge axis. The second lower joint rebar 22L extends from the joint surface lower portion 12L of the second joint end face 12B, and has the same position in the direction perpendicular to the bridge axis with the second upper joint rebar 22U at a predetermined distance in the direction perpendicular to the bridge axis. Is located in

  3 shows a III-III cross section in FIG. 2, and FIG. 4 shows an IV-IV cross section in FIG. In FIG. 3 and FIG. 4, hatching of concrete is omitted. As shown in FIGS. 2 to 4, the second joint rebar 22 is disposed at a position different from that of the first joint rebar 21 in the direction perpendicular to the bridge axis. More specifically, the second joint rebar 22 is disposed at the center of the first joint rebar 21 adjacent to each other in the direction perpendicular to the bridge axis. The first lower joint rebar 21L and the second lower joint rebar 22L have an extension length in which the major part overlaps with each other in the bridge axial direction. In addition, the first upper joint rebar 21U and the second upper joint rebar 22U also have an extension length in which most of them overlap in the bridge axial direction.

  As shown in FIG. 2 and FIG. 3, below the first upper joint reinforcing bar 21U and the second upper joint reinforcing bar 22U, they are disposed at predetermined intervals in the bridge axis direction and extend in the bridge axis perpendicular direction A plurality of upper reinforcement bars 25 (upper main bars) are arranged. The upper reinforcement bar 25 is a through bar having a length extending over all of the first upper joint bar 21U and the second upper joint bar 22U, and is disposed both inside the floor slab body 11 and inside the joint concrete 13 Ru. Since PC steel wire (not shown) is disposed in the floor slab main body 11 along the direction perpendicular to the bridge axis, the upper reinforcement rebar 25 in the floor slab main body 11 is the upper reinforcement rebar 25 in the joint concrete 13. It is thinner than that. In the present embodiment, five upper reinforcing bars 25 are disposed inside the joint concrete 13. The central three upper reinforcing bars 25 are disposed at the overlapping portion of the first upper joint reinforcing bar 21U and the second upper joint reinforcing bar 22U, and the two upper reinforcing bars 25 at both ends are the first upper joint reinforcing bar 21U and It is arrange | positioned out of the overlapping part with 2nd upper joint reinforcement 22U.

  As shown in FIGS. 2 and 4, above the first lower joint rebar 21L and the second lower joint rebar 22L, they are disposed at predetermined intervals in the bridge axis direction and extend in the direction perpendicular to the bridge axis A plurality of lower reinforcement bars 26 (bottom main bars) are arranged. The lower reinforcement bars 26 are through bars having a length extending over all the first lower joint reinforcement bars 21L and the second lower joint reinforcement bars 22L, and are disposed both inside the floor slab body 11 and inside the joint concrete 13 Ru. In the lower reinforcement bar 26 as well, the PC steel wire is disposed only in the floor slab main body portion 11, so that the diameter is smaller in the floor slab main body portion 11 than in the joint concrete 13. In the present embodiment, three lower reinforcing bars 26 are disposed inside the joint concrete 13. The three lower reinforcing bars 26 are disposed at the overlapping portion of the first lower joint reinforcing bar 21L and the second lower joint reinforcing bar 22L.

  As shown in FIG. 5, the fixing unit 23 has a flat shape that protrudes horizontally in the horizontal direction with respect to the joint rebars 21 and 22 and does not protrude in the vertical direction. The height (thickness) of the fixing portion 23 is equal to the diameter of the joint reinforcing bars 21 and 22, and the upper surface 23U and the lower surface 23L are aligned with the upper and lower ends of the joint reinforcing bars 21 and 22, respectively. The rear surface 23B on the joint reinforcing bar 21 and 22 side of the fixing unit 23 is a rectangular plane extending vertically, and the joint reinforcing bars 21 and 22 vertically extend from the center thereof. A front surface 23F on the projecting end side of the fixing unit 23 extends in parallel with the rear surface 23B, and four inclined surfaces 23S formed by chamfering are disposed around the front surface 23F. The front surface 23F is a rectangle substantially congruent with the rear surface 23B obtained by reducing the length of each side of the rear surface 23B to about one third, and the four inclined surfaces 23S are formed so as to align the rear edges. Therefore, the inclination angle with respect to the central part of the upper and lower inclined surfaces 23S is a value (about 45 degrees) larger than the inclination angle with respect to the central part of the left and right inclined surfaces 23S.

  The fixing unit 23 is formed into the above-described shape by heating the tips of the joint reinforcing bars 21 and 22 after the manufacture of the joint reinforcing bars 21 and 22 and hot forging. Alternatively, the fixing portion 23 may be formed into the above shape at the time of manufacturing the joint rebars 21 and 22, or may be formed as a separate member and be joined to the tips of the joint rebars 21 and 22 after manufacturing the joint rebars 21 and 22. Good. The fixing portion 23 transmits the bearing pressure to the joint concrete 13 when a compressive force or a tensile force in the bridge axial direction is applied to the joint rebars 21, 22 by radially projecting to the joint rebars 21, 22. The fixing force of the joint reinforcements 21 and 22 to the joint concrete 13 is improved.

  Next, the construction procedure of the floor slab 4 to which a pair of PCa floor slabs 8 arranged adjacent to each other by such a joint structure 10 is joined will be described.

  First, with reference to FIG. 6 and FIG. 7, Example 1 of the construction method of the floor slab 4 will be described.

  First, as shown in FIG. 6, a plurality of PCa floor slabs 8 in which the upper reinforcement bar 25 and the lower reinforcement bar 26 are bound to the joint bars 21 and 22 are prepared. The upper reinforcement bar 25 and the lower reinforcement bar 26 may be arranged later with respect to the PCa floor plate 8 manufactured in a factory etc., and the concrete of the floor plate main body 11 in the factory etc. producing the PCa floor plate 8 May be bound to the joint rebars 21 and 22 prior to casting. When this PCa floor plate 8 is placed at a predetermined position on the bridge girder 3, it becomes the second PCa floor plate 8b, and after it is placed on the bridge girder 3, the next PCa floor plate 8 is a predetermined one on the bridge girder 3. When placed in the position, it becomes the first PCa floor slab 8A. The PCa floor slab 8 is provided with a plurality of first upper joint reinforcing bars 21U and a plurality of first lower joint reinforcing bars 21L on the side of the first joint end face 12A on the right side in the drawing, and a plurality of pieces on the side of the second joint end face 12B on the left side in the drawing. A second upper joint reinforcing bar 22U and a plurality of second lower joint reinforcing bars 22L are provided.

  On the first joint rebar 21 side, four below the first upper joint rebar 21U (all three below the portion overlapping the second upper joint rebar 22U of the PCa floor plate 8 disposed close to each other and its left outside Upper reinforcement rebars 25 are arranged in advance. On the second joint reinforcing bar 22 side, one upper reinforcing bar on the lower side of the second upper joint reinforcing bar 22U (one on the right outside of the portion of the PCa floor plate 8 disposed close to the first upper joint reinforcing bar 21U overlapping) 25 reinforcements in advance, and 3 lower reinforcement rebars 26 above the second lower joint rebar 22L (all three above the portion overlapping with the first lower rebar 21L of the PCa floor plate 8 arranged closely) In advance.

  Next, as shown in FIG. 7A, the PCa floor slab 8 thus arranged is disposed as a first PCa floor slab 8A at a predetermined first position P1 on the bridge girder 3 (FIG. 1). Arrangement of the PCa floor plate 8 is performed by a crane. An imaginary line shown on the right side of the first PCa floor slab 8A indicates a predetermined second position P2 at which the second PCa floor slab 8B is to be disposed.

  Thereafter, as shown in FIG. 7 (B), another PCa floor plate 8 is lifted by a crane as the second PCa floor plate 8B, and moved from the first PCa floor plate 8A to a position farther than the second position P2 in plan view. Then, the second lower joint reinforcing bar 22L of the second PCa floor slab 8B is suspended to a predetermined height lower than the first upper joint reinforcing bar 21U of the first PCa floor slab 8A.

  Here, the predetermined height will be described on the assumption that the second PCa floor slab 8B is disposed completely at the same height as the first PCa floor slab 8A, and the floor slab 4 extends horizontally. With the predetermined height in the present embodiment, the second PCa floor slab 8B floats in the air (that is, the second PCa floor slab 8B is not in contact with the bridge girder 3 higher than the second position P2), and the fixing unit 23 It does not overlap in the height direction with the upper reinforcement bar 25 and the lower reinforcement bar 26 which are prearranged, and the height is not. Specifically, the upper end of the lower reinforcing bar 26 on the second lower joint bar 22L has a lower height than the lower end of the upper reinforcing bar 25 below the first upper joint bar 21U.

  When the second PCa floor slab 8B is lowered to this height, the second PCa floor slab 8B can be moved in the lateral direction without causing the reinforcing bars 21, 22, 25, 26 to interfere. Therefore, as shown in FIG. 7C, the second PCa floor slab 8B is horizontally moved to the side of the first PCa floor slab 8A in a floating state to be disposed above the second position P2. This lateral movement may be performed by a crane, or may be performed using tools such as human power and a lever block (registered trademark).

  After arranging the second PCa floor slab 8B above the second position P2, as shown in FIG. 7D, the second PCa floor slab 8B is hung and disposed at the second position P2. At this time, the reinforcing bars 21, 22, 25, 26 do not interfere with each other. Thereby, a gap G is formed between the first joint end face 12A of the first PCa floor slab 8A and the second joint end face 12B of the second PCa floor slab 8B, and the second upper joint rebar 22U of the second PCa floor plan 8B is the second The first lower joint reinforcing bar 21U of the 1PCa floor plate 8A is overlapped in the bridge axial direction, and the second lower joint reinforcing bar 22L of the second PCa floor plate 8B is overlapped with the first lower joint rebar 21L of the first PCa floor plate 8A in the bridge axial direction. As necessary, the upper reinforcement bar 25 is also bound to the second upper joint rebar 22U, and the lower reinforcement bar 26 is also bound to the first lower joint rebar 21L.

  Thereafter, the formwork 31 is assembled under the gap G, and concrete is poured into the gap G and hardened as shown in FIG. 7E, thereby the first upper joint rebar 21U and the first lower joint rebar The joint concrete 13 in which 21 L, the second upper joint rebar 22U and the second lower joint rebar 22L are wound is constructed. After the joint concrete 13 hardens, the formwork 31 is removed. Thereby, the joint structure 10 of the above-described configuration made of cast-in-place concrete is constructed, and the floor slab 4 formed by joining a pair of PCa floor slabs 8 arranged adjacent to each other by the joint structure 10 is constructed.

  According to the construction method of the floor slab 4 according to the present embodiment described above, the following operational effects can be obtained.

  That is, in the present embodiment, as shown in FIG. 6 and FIG. 7B, the three upper reinforcing bars 25 disposed below the overlapping portion of the upper joint bars 21U and 22U are used as the first PCa floor slab 8A. Together with the first upper joint rebar 21U of the first joint, and the three lower reinforcing bars 26 disposed above the overlapping portion of the lower joint rebars 21L and 22L together with the second lower joint rebar 22L of the second PCa floor plate 8B Keep it. Therefore, the arrangement | positioning in the field of reinforcement rebar 25 and 26 and a binding operation can be reduced.

  Then, as shown in FIG. 7A, the first PCa floor slab 8A is disposed prior to the predetermined first position P1, and as shown in FIG. 7B, the first PCa floor slab 8A is flatter than the second position P2. The second PCa floor slab 8B is suspended to a predetermined height at which the second lower joint rebar 22L of the second PCa floor slab 8B is lower than the upper joint rebar 21U of the first PCa floor slab 8A at a position distant from the first PCa floor slab 8A After being lowered, as shown in FIGS. 7C and 7D, the second PCa floor slab 8B is moved laterally to the first PCa floor slab 8A side at a predetermined height and disposed at the second position P2. Therefore, although the reinforcing bars 25 and 26 are prearranged, the operation of arranging the pair of PCa floor slabs 8 arranged adjacent to each other at a predetermined position interferes with each other between the reinforcing bars 21, 22, 25 and 26. You can do it without Finally, as shown in FIG. 7E, concrete is cast between the first PCa floor slab 8A disposed at the first position P1 and the second PCa floor slab 8B disposed at the second position P2. , The first PCa floor plate 8A and the second PCa floor plate 8B are joined together.

  Further, in the present embodiment, as shown in FIG. 5 and FIG. 6, when preparing the PCa floor plate 8, the fixing portion 23 is formed in a shape projecting only in the horizontal direction. Therefore, when the second PCa floor slab 8B to be arranged later is moved laterally to the first PCa floor slab 8A side at a predetermined height, the fixing unit 23 interferes with the reinforcing rebars 25 and 26 bound to the other PCa floor slab 8 Being prevented.

  Furthermore, as shown in FIG. 6, when previously binding the upper reinforcing bars 25, all three upper reinforcing bars 25 disposed below the overlapping portion are used as the second upper joint bars of the first PCa floor slab 8A. When bundling with 22 U and bundling the lower reinforcing bars 26 in advance, all three lower reinforcing bars 26 are bundled with the second lower joint bar 22L of the second PCa floor plate 8B. Then, as shown in FIG. 7B, when suspending the second PCa floor slab 8B, the lower reinforcement bar 26 does not overlap with the upper reinforcement bar 25 in the height direction, and the second PCa floor slab 8B is When the second PCa floor slab 8B is suspended to a floating height and the second PCa floor slab 8B is disposed at the second position P2, as shown in FIG. 7C, the second PCa floor slab 8B is floated. After the second PCa floor slab 8B is laterally moved and arranged above the second position P2, as shown in FIG. 7D, the second PCa floor slab 8B above the second position P2 is suspended. Therefore, the arrangement operation of the second PCa floor plate 8B accompanied by the lateral movement is easy.

  Next, with reference to FIG. 8 and FIG. 9, Example 2 of the construction method of the floor slab 4 will be described.

  First, as shown in FIG. 8, a plurality of PCa floor slabs 8 in which the upper reinforcing bar 25 and the lower reinforcing bar 26 are bound to the joint bars 21 and 22 are prepared. As in the first embodiment, the upper reinforcement bar 25 and the lower reinforcement bar 26 may be arranged later with respect to the PCa floor plate 8 manufactured at a factory etc., and the floor at the factory etc. producing the PCa floor plate 8 The joint reinforcing bars 21 and 22 may be bound before the concrete of the plate body 11 is cast.

  On the first joint rebar 21 side, one upper reinforcement rebar under the first upper joint rebar 21U (one on the left outside of the portion of the PCa floor plate 8 disposed close to the second upper joint rebar 22U overlapping with the second upper rebar) Arrange 25 in advance. On the second joint reinforcing bar 22 side, four below the second upper joint reinforcing bar 22U (all three below the portion overlapping the first upper joint reinforcing bar 21U of the PCa floor plate 8 disposed closely and its right outside Upper reinforcing rebar 25 of one of the two) in advance, and three above the second lower joint rebar 22L (3 above the portion overlapping with the first lower joint rebar 21L of the PCa floor slab 8 arranged close) The lower reinforcement bar 26 of all the books is arranged in advance.

  Next, as shown in FIG. 9A, the PCa floor slab 8 thus arranged is disposed as a first PCa floor slab 8A at a predetermined first position P1 on the bridge girder 3 (FIG. 1). Arrangement of the PCa floor plate 8 is performed by a crane. An imaginary line shown on the right side of the first PCa floor slab 8A indicates a predetermined second position P2 at which the second PCa floor slab 8B is to be disposed.

  Thereafter, as shown in FIG. 9 (B), another PCa floor plate 8 is lifted by a crane as the second PCa floor plate 8B, and moved from the first PCa floor plate 8A to a position farther than the second position P2 in plan view. Then, the second lower joint reinforcing bar 22L of the second PCa floor slab 8B is suspended to a predetermined height lower than the first upper joint reinforcing bar 21U of the first PCa floor slab 8A.

  Here, the predetermined height will be described on the assumption that the second PCa floor slab 8B is disposed completely at the same height as the first PCa floor slab 8A, and the floor slab 4 extends horizontally. The predetermined height in the present embodiment is the same height as the second position P2 (that is, the height at which the second PCa floor slab 8B contacts or is placed on the bridge girder 3). When the second PCa floor slab 8B is disposed at this height, the height (upper and lower ends do not overlap with the upper reinforcing rebar 25 and the lower reinforcing rebar 26 in which the fixing portion 23 is prearranged) in the height direction It is the height which becomes the same height. Specifically, the upper end of the upper reinforcement bar 25 below the second upper joint bar 22U coincides with the lower surface 23L of the fixing portion 23 of the first upper joint bar 21U, and the lower reinforcement bar 26 on the second lower joint bar 22L The lower end has a height that matches the upper surface 23U of the fixing portion 23 of the first upper joint rebar 21U.

  When the second PCa floor slab 8B is lowered to this height, the second PCa floor slab 8B can be moved in the lateral direction without causing the reinforcing bars 21, 22, 25, 26 to interfere. Therefore, as shown in FIG. 9C, the second PCa floor slab 8B is slid on the bridge girder 3 and laterally moved to the side of the first PCa floor slab 8A to be disposed at the second position P2. At this time, even if the reinforcing bars 21, 22, 25, 26 come into contact with each other, the reinforcing bars 21, 22, 25, 26 do not interfere with each other. When the reinforcing bars 21 22 25 26 are in contact with each other, specifically, when the fixing portion 23 contacts the upper reinforcing bar 25 or the lower reinforcing bar 26, inclined surfaces 23 S are formed at the upper and lower ends of the front surface 23 F of the fixing portion 23. Since it is formed, the upper reinforcement bar 25 or the lower reinforcement bar 26 is guided by the inclined surface 23S and passes below or above the fixing portion 23. This lateral movement may be performed using a tool such as a seat or a lever block (registered trademark) for reducing sliding resistance. In addition, in order to reliably prevent interference between the fixing portion 23 and the upper reinforcing bar 25 or the lower reinforcing bar 26, the second upper joint bar 22U and the second on the side to which the upper reinforcing bar 25 and the lower reinforcing bar 26 are bound. Temporary binding may be performed so that the ends of the lower joint reinforcing bars 22L are close to each other.

  Thereby, a gap G is formed between the first joint end face 12A of the first PCa floor slab 8A and the second joint end face 12B of the second PCa floor slab 8B, and the second upper joint rebar 22U of the second PCa floor plan 8B is the second The first lower joint reinforcing bar 21U of the 1PCa floor plate 8A is overlapped in the bridge axial direction, and the second lower joint reinforcing bar 22L of the second PCa floor plate 8B is overlapped with the first lower joint rebar 21L of the first PCa floor plate 8A in the bridge axial direction. As necessary, the upper reinforcing rebar 25 is also bound to the first upper joint rebar 21U, and the lower reinforcing rebar 26 is bound to the first lower joint rebar 21L.

  After that, the formwork 31 is assembled below the gap G, and concrete is poured into the gap G and hardened as shown in FIG. 9D, so that the first upper joint rebar 21U and the first lower joint rebar The joint concrete 13 in which 21 L, the second upper joint rebar 22U and the second lower joint rebar 22L are wound is constructed. After the joint concrete 13 hardens, the formwork 31 is removed. Thereby, the joint structure 10 of the said structure is constructed | assembled.

  Also in the second embodiment, as shown in FIGS. 8 and 9B, the three upper reinforcing bars 25 disposed below the overlapping portion of the upper joint reinforcing bars 21U and 22U are used as the second upper joint reinforcing bars 22U. By bonding three lower reinforcing bars 26 arranged above the overlapping portion of the lower joint bars 21L and 22L together with the second lower joint bar 22L, the site of the reinforcing bars 25 and 26 The arrangement in the second embodiment is the same as that of the first embodiment in that the binding operation can be reduced.

  Further, as shown in FIGS. 5 and 8, when preparing the PCa floor plate 8, the fixing portion 23 is formed in a shape projecting only in the horizontal direction, as shown in FIG. 9C. When the second PCa floor slab 8B is moved laterally, interference with the upper reinforcing rebar 25 and the lower reinforcing rebar 26 of the fixing portion 23 on the first PCa floor slab 8A side is prevented, and the upper and lower reinforcing rebars 25 and 26 are the second joint rebar 22 It becomes possible to arrange the second PCa floor slab 8B bound in the predetermined position.

  Furthermore, in the present embodiment, when the second PCa floor slab 8B is suspended, as shown in FIG. 9B, the second PCa floor slab 8B is suspended to the same height as the second position P2, and the second PCa floor is suspended. When placing the plate 8B in the second position P2, as shown in FIG. 9C, the second PCa floor plate 8B is slid and moved laterally. Therefore, the second PCa floor slab 8B can be laterally moved and disposed at the second position P2 regardless of which PCa floor slab 8 the reinforcing reinforcing bars 25 and 26 are arranged in advance.

  And in this embodiment, as shown in Drawing 2-Drawing 4, joint structure 10 is prolonged from the upper part and the lower part of the 1st joined end face 12A which extends in the direction perpendicular to the bridge axis in the 1st PCa floor slab 8A. The first upper joint rebar 21U and the plurality of first lower joint rebars 21L, each having a fixing portion 23 at their tips, are arranged at intervals in the direction perpendicular to the bridge axis, and the first PCa floor slab 8A with respect to the bridge Spaced in the direction perpendicular to the bridge axis so as to extend from the upper and lower portions of the second bonding end surface 12B opposite to the first bonding end surface 12A of the second PCa floor slab 8B closely spaced with a gap G in the axial direction A plurality of second upper joint reinforcing bars 22U and a plurality of second upper joint reinforcing bars 22U each having a fixing portion 23 at the tip and having an extension length overlapping with the corresponding first upper joint reinforcing bar 21U or first lower joint reinforcing bar 21L. Lower joint rebar 22L The upper reinforcement rebar 25 extending in the direction perpendicular to the bridge axis below the overlapping portion of the first upper joint rebar 21U and the second upper joint rebar 22U, and the first lower joint rebar 21L and the second lower joint rebar 22L Lower reinforcement bar 26 extending in a direction perpendicular to the bridge axis above the overlapping portion, first upper joint bar 21U, first lower joint bar 21L, second upper joint bar 22U, second lower joint bar 22L, upper reinforcement bar The joint concrete 13 constructed in the gap G so as to entrap the 25 and the lower reinforcement bar 26 is provided, and the fixing portion 23 is formed in a shape that protrudes in the horizontal direction only.

  Therefore, even if a part of the upper reinforcing rebar 25 and the lower reinforcing rebar 26 is arranged in advance, as described in the first and second embodiments, the rebars 21, 22, 25, 26 do not interfere with each other. The second PCa floor slab 8B can be moved laterally and disposed at a predetermined second position P2.

  Although the description of the specific embodiment is finished above, the present invention can be widely modified and implemented without being limited to the above embodiment. For example, in Example 1, all (six) of the upper reinforcing rebar 25 and the lower reinforcing rebar 26 arranged at the overlapping portion of the joint rebars 21 and 22 are arranged in advance in one side of the PCa floor slab 8, Only some of them may be arranged in advance. In this case, although the upper reinforcement bar 25 or the lower reinforcement bar 26 must be arranged after the arrangement of the PCa floor slab 8, the number of the reinforcement bars 25 is reduced, which makes the operation relatively easy. Further, in the second embodiment, all (six) of the upper reinforcement bar 25 and the lower reinforcement bar 26 in the overlapping portion are arranged on the second PCa floor slab 8B, but a part or all of them are the first PCa floor slab You may arrange to 8A. When the upper reinforcing bar 25 and the lower reinforcing bar 26 are arranged on both the first PCa floor plate 8A and the second PCa floor plate 8B, the upper reinforcing bar 25 and the lower reinforcing bar 26 on the proximal side of the joint bars 21 and 22 are bound It is good to do. This makes it possible to shorten the distance over which the second PCa floor slab 8B has to slide in the lateral direction. In addition, the specific configuration or arrangement of each member or portion, the number, the angle, the procedure, and the like can be appropriately changed without departing from the scope of the present invention. On the other hand, not all of the components shown in the above embodiment are necessarily essential, and can be selected as appropriate.

4 floor version 8 PCa floor version 8A 1st PCa floor version 8B 2nd PCa floor version 10 joint structure 11 floor version main body 12 joint end face 12A 1st joint end face 12B 2nd joint end face 12L lower joint surface 12U upper joint surface 13 joint concrete 21 1st joint reinforcing bar 21L 1st lower joint reinforcing bar 21U 1st upper joint reinforcing bar 22 2nd joint reinforcing bar 22L 2nd lower joint reinforcing bar 22U 2nd upper joint reinforcing bar 23 fixing part 25 upper reinforcing bar 26 lower reinforcing bar G gap P1 first position P2 second position

Claims (5)

A method of constructing a floor slab comprising joining a pair of PCa floor slabs arranged adjacent to each other by a joint structure made of cast-in-place concrete,
Preparing a plurality of PCa deck slabs in which upper joint rebars and lower joint rebars having fixing portions at their tips extend from the upper and lower portions of the joint end surface;
Pre-bundling the upper reinforcing rebar disposed below the overlapping portion of the upper joint reinforcing bars of the pair of PCa floor slabs with the upper joint reinforcing bars of at least one of the PCa floor slabs;
Pre-bundling a lower reinforcing rebar disposed above the overlapping portion of the lower joint reinforcing bars of the pair of PCa floor slabs with the lower joint reinforcing bars of at least one of the PCa floor slabs;
Placing the first PCa floor slab to be placed ahead of the pair of the PCa floor slabs in a predetermined first position;
Of the pair of PCa decks, a second PCa deck to be placed later is separated from the first PCa deck in plan view than a predetermined second position where the second PCa deck should be placed. Suspending the lower joint reinforcing bar of the second PCa floor slab to a predetermined height lower than the upper joint reinforcing bar of the first PCa floor slab at a position;
Moving the second PCa floor slab laterally to the first PCa floor slab side at the predetermined height, and arranging the second PCa floor slab at the second position;
Concrete is cast between the first PCa floor slab arranged at the first position and the second PCa floor slab arranged at the second position, and the first PCa floor slab and the second PCa floor slab are A method of constructing a floor slab, comprising the steps of:   The method for constructing a floor slab according to claim 1, wherein, in the step of preparing the PCa floor slab, the fixing portion is formed in a shape projecting only in the horizontal direction. In the step of previously binding the upper reinforcing rebar, all the upper reinforcing rebars are bound to the upper joint rebar of the first PCa floor plate,
In the step of previously binding the lower reinforcing rebar, all the lower reinforcing rebars are bound to the lower joint rebar of the second PCa floor plate,
In the step of suspending the second PCa floor slab, the second PCa floor slab is suspended so that the lower reinforcement bar does not overlap with the upper reinforcement bar in the height direction and the second PCa floor slab floats.
Placing the second PCa floor slab in the second position comprises:
Moving the second PCa floor slab laterally with the second PCa floor slab floating, and disposing the second PCa floor slab above the second position;
The method for constructing a floor slab according to claim 1 or 2, further comprising the step of suspending the second PCa floor slab above the second position. In the step of suspending the second PCa floor slab, the second PCa floor slab is suspended to the same height as the second position,
The method for constructing a floor slab according to claim 2, wherein the step of disposing the second PCa floor slab at the second position includes sliding the second PCa floor slab and moving it laterally. A plurality of first PCa floor slabs are spaced apart in a direction perpendicular to the bridge axis so as to extend from upper and lower portions of a first joint end face extending in the direction perpendicular to the bridge axis in the first PCa floor slab 1 upper joint rebar and multiple first lower joint rebars,
The bridge shaft so as to extend from the upper and lower portions of the second bonding end surface facing the first bonding end surface of the second PCa floor slab closely arranged with a gap in the bridge axial direction with respect to the first PCa floor slab A plurality of second upper joint rebars spaced apart in a perpendicular direction, each having a fixing portion at its tip, and having an extension length overlapping the corresponding first upper joint rebar or the first lower joint rebar And a plurality of second lower joint rebars,
An upper reinforcing bar extending in a direction perpendicular to the bridge axis below the overlapping portion of the first upper joint bar and the second upper joint bar;
A lower reinforcing bar extending in a direction perpendicular to the bridge axis above the overlapping portions of the first lower joint reinforcing bar and the second lower joint reinforcing bar;
Joint concrete constructed in the gap so as to wind in the first upper joint reinforcing bar, the first lower joint reinforcing bar, the second upper joint reinforcing bar, the second lower joint reinforcing bar, the upper reinforcing bar and the lower reinforcing bar Equipped with
The joint structure of a PCa floor slab characterized in that the fixing portion is formed in a shape projecting only in the horizontal direction.

Images