JP5337122B2 - Precast floor slab and its installation method - Google Patents

Description

  The present invention relates to a precast floor slab and a method for installing the same.

Conventionally, as shown in FIGS. 17 (a) and 17 (b), the precast concrete floor slab body 20 is embedded in advance so as to project both ends of the looped reinforcing bar or loop strip steel plate 21 from the precast concrete floor slab body 20. Precast concrete slab with loop joint (hereinafter referred to as precast floor slab with loop joint) in which loop joint 5c formed in an arc shape from each end in the thickness direction of the floor slab is projected in both ends in the bridge axis direction. Or simply a precast floor slab or simply a floor slab) 2 is known (for example, Patent Document 1).
The precast floor slab 2 with a loop-shaped joint is a horizontally long floor slab in a direction perpendicular to the bridge axis, and such a precast floor slab 2 with a loop-shaped joint is adjacent to a girder 1 (see FIG. 10) parallel to the bridge axis direction. ) Installed with mortar as appropriate over the top.

  As shown in FIGS. 15 and 16, the floor slabs are connected to each other as shown in FIG. 15 and FIG. Alternatively, they are arranged so as to overlap (both are shifted in the direction perpendicular to the bridge axis), and reinforcing reinforcing bars 9 are inserted into the loop shape from the right angle direction of each loop joint reinforcing bar, and between the floor slabs It is a structure in which a curable material 4 made of concrete is placed in the filling portion (connecting portion 14), and the adjacent precast concrete floor slabs 2 are connected to each other at an interval (see, for example, Patent Document 1). .

JP 2005-83072 A

As shown in FIG. 15, when connecting the precast slab 2 with a loop joint adjacent in the bridge axis direction, the reinforcing bars 9 in the direction perpendicular to the bridge axis cannot be dropped into the loop joint 5c from above, Reinforcing bars 9 are arranged from one end side in the direction perpendicular to the bridge axis to the other end side in the direction perpendicular to the bridge axis in a loop-shaped space formed by the mutual loop-shaped joint 5c. As a form for arranging the reinforcing bars 9 in the direction perpendicular to the bridge axis, a form in which the long rebar 22 of the first example shown in FIGS. 10 to 12 is arranged, and a short rebar 23 as shown in FIGS. 13 to 14 are arranged. There are two forms.
The steel material used for each of the above-mentioned reinforcing bars is a reinforcing bar with a rib (node) or a (deformed) steel bar.

In the case of the form of the first example shown in FIGS. 10 to 12, the length of the floor slab 2 is the same as the length of the floor slab in the direction perpendicular to the bridge axis from the road shoulder side end or the central separator side end. The long rebar 22 is inserted into the loop-shaped space in the connecting portion 14 using a crane, an aerial work vehicle, a long rebar suspension jig, or the like.
In this case, as shown in FIG. 10 and FIG. 11, an obstacle 26 such as a soundproof wall extends over a column 25 erected or held on a support member 24 attached to the girder 1 on the side of the floor slab 2. Since these obstacles 26 interfere with the insertion work, the obstacles such as the soundproof walls are temporarily removed as shown by the dotted lines in FIG. As indicated by the arrows in the figure, the suspension is lifted in a state where it is supported by the hanging metal fittings extended from the crane, etc., and transported in the direction perpendicular to the bridge axis as indicated by the arrows. The long rebar 22 has been disposed by being disposed so as to be sent to the wire.
Although illustration is omitted, when a safety net is provided outside the support column 25, it becomes an obstacle to insertion work of the long rebar, so that the worker becomes an obstacle to the insertion work. Another worker was inserting the long rebar 22 in a state where the safety net of the part was partially turned up and an insertion work space was secured on the side of the floor slab.

Further, as described above, when the obstacle 26 such as the soundproof wall cannot be removed, as shown in FIG. 13 and FIG. By embedding and arranging a plurality of reinforcing bars 21 in the direction perpendicular to the bridge axis (seven in the case of illustration), between the adjacent large-diameter loop reinforcing bars 21 with an interval therebetween The insertion space is ensured by providing a level difference between the upper end level of the inner diameter of the loop-shaped joint 5c with the large-diameter loop-shaped reinforcing bar and the upper end level of the outer diameter of the loop-shaped joint 5c with the smaller-diameter loop-shaped reinforcing bar. In addition, two or more short rebars 23 having dimensions shorter than the length of the slab 2 in the direction perpendicular to the bridge axis are arranged in the right direction (in the case of illustration) and in the left direction (not shown), respectively. (If necessary, connect two or more short rebars 23 to the bridge axis. Close move in direction, are arranged close to the ends of the short reinforcing bars 23 adjacent to each other in series to the bridge axis perpendicular direction).
In this case, the short rebar 23 to be inserted is bent, and the rib of the short rebar 23 hits the loop joint 5 and resists, so that it may be difficult to insert manually. In this case, FIG. 13 and FIG. As indicated by an arrow in FIG. 14, the insertion work is performed while hitting the short rebar 23 to be inserted with a large hammer or the like, and there is a problem that the short rebar 23 is damaged or noise is generated by the hit.

  Further, conventionally, as shown in FIGS. 18 (a) and 18 (b), an upper joint rebar 5a and a lower joint rebar 5b projecting from the precast floor slab 2 in the bridge axis direction are arranged at intervals in the vertical direction and the bridge shaft. In the precast floor slab 2 provided with a large number of gaps in the perpendicular direction, the end surface in the bridge axis direction of the precast floor slab, the floor slab end surface 6 on the base end side of the upper joint rebar 5a, and the lower joint rebar 5b There is a technique in which the precast floor slab 2 is formed such that the floor slab end surface 6 of the overhang base end is the same inclined end surface (see, for example, Patent Document 2).

In the precast slab of the form shown in FIG. 18, the upper joint rebar 5a and the lower joint rebar 5b are a joint rebar with a crimp grip (or with an end band) in which a crimp grip (end band) 3 is provided at the tip of the joint rebar. Since the bridge axial direction end K is open between the upper joint reinforcing bar 5a and the lower joint reinforcing bar 5b, it extends in the direction perpendicular to the bridge axis from the bridge axis direction. Although there is an advantage that the reinforcing reinforcing bars 9 can be arranged, in the conventional case, after the precast floor slab is installed, the reinforcing reinforcing bar arranging method as described above is adopted. However, there is a problem that the construction cost becomes high as the length becomes longer.
In the above case, since the end surfaces in the bridge axis direction on the base end side of the upper joint rebar 5a and the lower joint rebar 5b are the same inclined surface, the lower joint rebar 5b is located below the upper joint rebar 5a. If the pre-reinforced floor slabs adjacent to each other in the bridge axis direction are arranged in order when a plurality of reinforcing bars 9 in the direction perpendicular to the bridge axis are temporarily retained between Since the front end portion of the lower joint reinforcing bar 5b in Fig. 2 interferes with the reinforcing reinforcing bar 9 disposed on the precast floor slab 2 installed in advance, the precast floor slab 2 is adjacent to each other with a gap in the direction perpendicular to the bridge axis. There is a problem that it is difficult to erection in the bridge axis direction.

In the case of the precast slab of the form shown in FIG. 17, as shown in FIGS. 8 and 9, the loop joint 5c collides with the overhanging support portion 7 for supporting the interstitial portion concrete, so that the overhanging There is a problem that the support 7 may be damaged, and when the precast floor slab 2 is slid in the bridge axis direction, the buffer layer 8 made of a sole sponge installed on the beam 1 may be damaged. There was a problem that there was.
The present invention can solve the above-mentioned conventional problems, can remove the obstacles such as the soundproof wall or can lift the safety net, can shorten the construction work period of the precast slab construction, It is an object of the present invention to provide a precast floor slab capable of reducing the construction cost and a method for installing the same.

In order to advantageously solve the above-mentioned problem, in the precast floor slab with the reinforcing-bar temporary storage housing groove in the direction perpendicular to the bridge axis according to the first invention, the upper joint reinforcing bar and the lower part projecting from the precast floor slab body in the bridge axis direction In the precast floor slab having a plurality of joint rebars arranged at intervals in the vertical direction and spaced in the direction perpendicular to the bridge axis, the bridge axis direction end of the floor slab body at the base end on the overhang side of the upper joint rebar The upper floor slab end face of the part is provided so as to be displaced closer to the center part in the bridge axis direction than the lower floor slab end face of the bridge axis direction end part of the floor slab body at the overhanging base end part in the lower joint reinforcing bar. A stepped portion that is continuous in a direction perpendicular to the bridge axis is provided between the end face of the upper floor slab and the end face of the lower floor slab, and the base end of each of the plurality of upper joint reinforcing bars and the bridge axis direction of the precast floor slab Steps And by, and wherein the temporary housing groove for reinforcing rebar continuous to the bridge axis perpendicular direction is formed.
In the second invention, in the precast floor slab with the reinforcing-rebar temporary storage groove in the direction perpendicular to the bridge axis according to the first invention, the stepped portion is opposed to the lower surface on the proximal end side of the upper joint reinforcing bar at a distance. And a step portion having an inclined upper surface or a flat upper surface, and one end side of the inclined upper surface or the flat upper surface is connected to the lower floor slab end surface, and on the inclined upper surface or the flat upper surface. The other end side is connected to the upper floor slab end face.
In the precast floor slab temporarily holding the reinforcing bar in the direction perpendicular to the bridge axis according to the third invention, the temporary storage groove in the precast floor slab with the reinforcing bar temporary placing groove in the direction perpendicular to the bridge axis according to the first or second invention. Further, one or a plurality of reinforcing bars in the direction perpendicular to the bridge axis are arranged and temporarily held by a temporary suspension provided on the upper joint reinforcing bar.
In the precast slab erection method of the fourth invention, the precast slab temporarily holding the reinforcing bars in the direction perpendicular to the bridge axis of the third invention is arranged across the girders spaced in the direction perpendicular to the bridge axis, Expand one or more reinforcing bars in the direction perpendicular to the bridge axis temporarily held on one of the precast slabs adjacent in the bridge axis direction to either the upper joint reinforcing bar side or the lower joint reinforcing bar side. One or a plurality of reinforcing bars in the direction perpendicular to the bridge axis, which are reinforced and bonded to the precast slab, are temporarily held on the other side of the upper joint or the lower joint It is characterized by unfolding and binding the reinforcing bar and the joint bar.

According to the first invention, in the precast floor slab with the reinforcing reinforcing bar temporary storage groove in the direction perpendicular to the bridge axis according to the first invention, the upper joint reinforcing bar and the lower joint reinforcing bar protruding from the precast floor slab body in the bridge axis direction are vertically moved. A precast floor slab arranged at intervals and at a distance perpendicular to the bridge axis, and an upper floor slab at the bridge axis direction end of the floor slab body at the base end portion of the overhang side of the upper joint reinforcing bar The upper floor slab is provided such that the end surface is displaced closer to the center portion in the bridge axis direction than the lower floor slab end surface of the bridge axis direction end portion of the floor slab body at the base end portion on the overhanging side of the lower joint reinforcing bar. A stepped portion is provided between the end face and the end face of the lower floor slab in a direction perpendicular to the bridge axis, and a base end portion of each of the upper joint reinforcing bars, and the stepped portion in the bridge axis direction of the precast floor slab, Bridge axis Temporary storage slots for reinforcing reinforcing bars that are continuous in the angular direction are formed, so the space between the girders where the precast floor slabs should be installed with the reinforcing reinforcing bars placed and temporarily held in the temporary storage slots for reinforcing reinforcing bars Even if the bridge is erected in the direction of the bridge axis, the tip of the joint reinforcement in the precast slab that is installed downstream is reinforced in the direction perpendicular to the bridge axis. Since there is no interference with the reinforcing bars, the precast floor slab can be transported with the reinforcing bars, and the reinforcing bars can be transported at the same time as the precast floor slabs. Because it is attached to the precast floor slab, handling of the reinforcing steel bar is improved, and the precast floor slab including the reinforcing steel bar can be installed easily in a short construction period. Effects such can be inexpensive can be obtained.
In the second invention, in the precast floor slab with the reinforcing-rebar temporary storage groove in the direction perpendicular to the bridge axis according to the first invention, the stepped portion is opposed to the lower surface on the proximal end side of the upper joint reinforcing bar at a distance. And a step portion having an inclined upper surface or a flat upper surface, and one end side of the inclined upper surface or the flat upper surface is connected to the lower floor slab end surface, and on the inclined upper surface or the flat upper surface. Since the other end is connected to the end face of the upper floor slab, according to the second invention, the reinforcing bar is arranged on the inclined upper face or the flat upper face on the floor slab end on the lower side of the upper joint reinforcing bar. As a result, it is possible to obtain an effect that the reinforcing reinforcing bars can be arranged and transported and installed on the precast floor slab so as not to protrude from the floor slab end on the base end side of the lower joint reinforcing bar.
In the precast floor slab that temporarily holds the reinforcing bar in the direction perpendicular to the bridge axis according to the third invention, the temporary storage groove in the precast floor slab with the reinforcing bar temporary storage groove in the direction perpendicular to the bridge axis according to the first or second invention. In addition, one or a plurality of reinforcing bars in the direction perpendicular to the bridge axis are arranged and temporarily held by temporary suspensions provided on the upper joint reinforcing bars, so that the reinforcing reinforcing bars can be easily attached to a large number of upper connecting reinforcing bars. Effects such as being able to be supported are obtained.
In the precast slab erection method of the fourth invention, the precast slab temporarily holding the reinforcing bars in the direction perpendicular to the bridge axis according to the third invention is constructed across the girders spaced in the direction perpendicular to the bridge axis and the bridge. One or a plurality of reinforcing bars in the direction perpendicular to the bridge axis, which can be easily installed without interfering with an interval in the axial direction, and temporarily held on one of the precast floor slabs adjacent in the bridge axis direction One or a plurality of joint reinforcing bars in the direction perpendicular to the bridge axis, which are expanded on either the upper joint reinforcing bar side or the lower joint reinforcing bar side to bind the joint reinforcing bars together and are temporarily held by the other precast slab Is expanded to either the upper joint reinforcing bar side or the lower joint reinforcing bar side to bind the joint reinforcing bars to each other, so that the reinforcing reinforcing bars are connected to the upper joint from one and the other precast slabs adjacent to each other in the bridge axis direction. Easily placed on the reinforcing bar side and the lower joint reinforcing bar side to easily bind the reinforcing bars and reinforcing bars of the precast floor slabs adjacent to each other in the bridge axis direction. Thus, it is possible to obtain an effect that a construction method for a precast floor slab with a low construction cost can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a precast floor slab with a joint reinforcing bar temporary accommodation groove in a direction perpendicular to a bridge axis according to an embodiment of the present invention, wherein (a) is a plan view and (b) is a front view. It is the sectional view on the aa line of Fig.1 (a). (A) is a top view which shows the precast slab which temporarily hold | maintained the joint reinforcement of a bridge axis orthogonal direction, (b) is a front view of (a). It is a front view which expands and shows a part of FIG.3 (b). (A) is a precast floor slab that temporarily holds the joint rebar in the direction perpendicular to the bridge axis, and is arranged across the adjacent beams in the direction perpendicular to the bridge axis so that the joint rebar has an overlap in the bridge axis direction. The front view which shows a state, (b) expand | deploys several reinforcement reinforcement bars of the direction perpendicular to a bridge axis from the state of (a) to the upper joint reinforcement side and the lower joint reinforcement side respectively at intervals in the bridge axis direction. It is a front view which shows the state arrange | positioned. FIG. 6B is a plan view showing a state in which reinforcing bars are arranged so as to extend in the direction perpendicular to the bridge axis across the joints of adjacent precast slabs in the plan view of FIG. It is a top view which shows the state which filled the joint part of the floor slab adjacent to a bridge axis direction from the state shown in FIG. 6 with concrete or a non-shrink mortar. It is explanatory drawing in the case of installing the precast concrete floor slab with a conventional loop-shaped joint arranged in series in the bridge axis direction. In the case shown in FIG. 8, the loop joint in one precast concrete floor slab with a loop joint interferes with the overhang bearing part in the other precast concrete floor slab with a loop joint and damages the overhang bearing part. It is a vertical front view which shows the state which exists. It is the partially longitudinal front view seen from the bridge axis direction for demonstrating the 1st example in the case of arrange | positioning the joint reinforcement of a bridge axis orthogonal direction between the floor slabs adjacent to a bridge axis direction. It is a figure which expands and shows a part of FIG. It is a top view for demonstrating the 1st example in the case of arrange | positioning the joint reinforcement of a bridge axis orthogonal direction between the floor slabs adjacent to a bridge axis direction. It is the partially longitudinal front view seen from the bridge-axis direction for demonstrating the 2nd example of the connection method of the adjacent PCa floor slab which has a conventional loop joint. It is the figure which expanded a part of 2nd example shown in FIG. 13, and was seen from the front. It is the vertical side view seen from the bridge axis perpendicular direction which shows the conventional connection structure of floor slab which arranged the reinforcing bar of the bridge axis perpendicular direction in the connection part between floor slabs. It is a vertical side view which shows the normal state which filled the connection part of the conventional floor slab shown in FIG. 15 with the concrete. An example of a precast floor slab is shown, Comprising: (a) is a top view, (b) is a longitudinal front view. The other example of a precast floor slab is shown, Comprising: (a) is a top view, (b) is bb sectional drawing of (a). It is explanatory drawing for showing the difference of the joint space | interval when it is set as the connection structure of the precast floor slab of this invention, and the connection structure of the conventional precast slab.

    Next, the present invention will be described in detail based on the illustrated embodiment.

  1 and 2 show a precast floor slab 2 with a joint reinforcing bar temporary accommodation groove in a direction perpendicular to the bridge axis according to an embodiment of the present invention. FIG. 1 (a) is a plan view and FIG. 1 (b). Is a front view, and FIG. 2 is a sectional view taken along line aa in FIG.

  A steel tubular body 3 is fitted to both ends of a reinforcing bar having a predetermined length, and a crimping grip (end band) 10 that is crushed and deformed and fixed by crimping to the reinforcing bar is formed. An upper joint rebar 5a and a lower joint rebar 5b composed of rebars (joint rebars with end bands) are configured.

Since the upper joint rebar 5a and the lower joint rebar 5b made of a joint rebar with a crimping grip do not require hot working such as thermoforming on the rebar, a commercially available inexpensive rebar can be used. A commercially available inexpensive member can also be used for the body 3, and the length of the steel tubular body 3 is also flexible. Further, compared to the case of using a custom-made reinforcing bar having a diameter-expanded end part that gradually expands the end part of the reinforcing bar, the upper joint reinforcing bar 5a and the lower joint reinforcing bar 5b, which are joint reinforcing bars with a crimp grip used in the present invention, are used. Various commercially available reinforcing bars and steel cylinders can be used, and the degree of freedom of production is remarkably high, and the production is also easy.
The upper joint rebar 5a and the lower joint rebar 5b, which are joint rebars with a crimping grip as described above, are located at predetermined positions on the upper and lower parts of the floor slab, and the crimping grips 10 are at both ends in the bridge axis direction. The concrete is placed and hardened so as to be positioned and embedded so as to embed an intermediate portion of the reinforcing bar, thereby forming a precast concrete floor slab 2 with a crimped grip joint.

Then, in the precast concrete floor slab 2 with a crimped grip joint according to the present invention, the upper joint rebar 5a and the lower joint rebar 5b made of the joint rebar with the above-mentioned crimp grip are connected to the precast reinforced concrete floor slab or prestressed thereto. It is applied to the joint reinforcement of precast reinforced concrete floor slabs.
And the upper floor slab end surface 11 of the bridge axial direction end part which consists of the vertical side surface in the base end side of the overhanging side in the upper joint reinforcing bar 5a is the bridge axis direction of the floor slab body in the overhanging base end part of the lower joint reinforcing bar 5b. The upper floor slab end surface 11 is provided at a base end side of the upper joint reinforcing bar 5a, and is disposed so as to be displaced closer to the center portion in the bridge axis direction than the lower floor slab end surface 12 formed of the vertical side surface of the end portion. A step portion 13 having an inclined surface or a flat surface 6 continuous in a direction perpendicular to the bridge axis is provided between the bottom floor slab end surface 12 and the base end portion of the upper joint reinforcing bar group by the above-mentioned multiple upper joint reinforcing bars 5a. And the stepped portion 13 including the inclined surface or the flat surface 6 in the bridge axis direction in the precast floor slab 2, the temporary storage grooves 15 for the joint reinforcing bars in the direction perpendicular to the bridge axis are continuously provided in the direction perpendicular to the bridge axis. Formed to extend There is a precast slab 2 that was.

In the precast floor slab 2 of the present invention, as shown in FIG. 3, the temporary storage housing groove 15 on the lower side of each upper joint reinforcing bar 5a in the bridge axis direction has a reinforcing reinforcing bar as shown in FIG. One or a plurality of wires 9 are arranged so as to extend in the direction perpendicular to the bridge axis, and are temporarily held by a temporary holder 16 such as a steel wire or a wire to be suspended from the proximal end side of the upper joint rebar 5a. Has been placed.
In the illustrated form, the temporary holding tool 16 made of steel wire is arranged so as to be held from the front and back of the entire reinforcing reinforcing bar 9 so that both ends of the steel wire are wound around each other on the upper joint reinforcing bar 5a. The reinforcing reinforcing bars 9 are securely fixed to the upper joint reinforcing bars 5a.

As described above, the precast reinforced concrete floor slab 2 is appropriately transported in a state in which the reinforcing steel bars 9 are temporarily held, and is arranged across the girders, and is installed in series in the bridge axis direction. The precast floor slab 2 adjacent in the direction is installed with the gap of the predetermined padding portion 14 being maintained.
Thereafter, a frame (not shown) is disposed across the precast slabs 2 adjacent to each other in the bridge axis direction, the temporary holder 16 is removed, and as shown in FIGS. 5B and 6. As described above, the reinforcing reinforcing bars 9 in the bridge axis direction and the other reinforcing reinforcing bars 9 are respectively arranged on the lower side of the upper joint reinforcing bar 5a or on the upper side of the lower connecting reinforcing bar 5b, so that the reinforcing reinforcing bar 9 and the upper joint reinforcing bar 5a or the lower joint reinforcing bar 5b. Secure with a wire or the like.

  Then, as shown in FIG. 7, each precast floor slab is filled with concrete (or curable material 4 such as non-shrink mortar) in the interstitial portion 14 and, as appropriate, stud studs fixed to the girders 1 are embedded. By filling the recesses 2 with the curable material, the precast floor slabs 2 adjacent to each other in the bridge axis direction and the girder 1 are integrated.

  Between the upper floor slab end surface and the lower floor slab end surface, an inclined surface continuous in a direction perpendicular to the bridge axis or a flat surface may be used. The base end portion of the upper joint rebar 5a and the end of the precast floor slab 2 in the bridge axis direction may be used. The temporary storage groove 15 that is continuous in the direction perpendicular to the bridge axis may be provided in the portion, and the temporary storage groove 15 having a substantially rectangular shape or the like is formed as a schematic cross-sectional form.

  In the illustrated embodiment, one end side on the lower level side of the inclined upper surface or flat upper surface is connected to the lower floor slab end surface 12, and the other end on the upper level side of the inclined upper surface or flat upper surface. Since the side is connected to the end surface of the upper floor slab, the shape of the end surface of the precast floor slab in the bridge axial direction end can be a simple cross-sectional shape, and the lower joint reinforcement 5b in the precast floor slab The lower thickness dimension can also be increased, and the rigidity can be improved.

  In the above-described embodiment, a plurality of reinforcing bars 9 in the direction perpendicular to the bridge axis are arranged in the temporary storage groove 15 in the precast floor slab 2 with the joint reinforcing bar temporary storage groove in the direction perpendicular to the bridge axis, and the upper joint reinforcement described above. The temporary holding 16 made of steel wire provided in 5a showed a form of temporary holding so as to be suspended from the upper joint rebar 5a, but when carrying out the present invention, an inclined surface or flat surface 6 on the floor slab side, The upper joint reinforcing bar 5a and the temporary holding 16 may jointly hold the reinforcing reinforcing bar 9 temporarily.

  Next, the construction method of the precast floor slab of the present invention will be described. The precast floor slab 2 temporarily holding the joint reinforcing bars in the direction perpendicular to the bridge axis as shown in FIG. 3 is appropriately lifted by a crane or the like, or already connected. The crane is lifted by a simple crane that runs on the existing precast slab 2 and is installed over a plurality of girders 1 that are parallel to each other at an interval in the direction perpendicular to the bridge axis. A plurality of reinforcing bars 9 in the direction perpendicular to the bridge axis temporarily held on the precast floor slab 2 are placed on either the upper joint reinforcing bar 5a side or the lower joint reinforcing bar 5b side so as to have a predetermined interval in the bridge axis direction. The joint reinforcing bars and the reinforcing reinforcing bars 9 are unfolded and a plurality of reinforcing reinforcing bars 9 in a direction perpendicular to the bridge axis temporarily held on the other precast slab 2 are connected to the upper joint so as to be spaced at a predetermined interval in the bridge axis direction. The bridge is constructed so that the upper joint rebar 5a or the lower joint rebar 5b and the reinforcing rebar 9 are fixed to each other by a wire or the like by binding or welding to the other side of the hand rebar 5a or the lower joint rebar 5b. The precast floor slabs 2 are sequentially installed in series in the axial direction, and a formwork is appropriately disposed between adjacent floor slabs in the bridge axial direction, and the padding portion 14 is made of concrete (or non-shrink mortar). The curable material 4 is filled and solidified so that the precast floor slabs 2 adjacent in the bridge axis direction are connected and integrated.

  In addition, as shown in the upper and lower sides of FIG. 19, in the case of the precast floor slab 2 provided with the joint reinforcing bar 5 (5a, 5b) with an end band used in the present invention, the width of the precast floor slab when producing this is as follows. , The width of the factory production line + the joining width (≦ transportable width) can be assigned with this floor slab width L. Therefore, than the case of the floor slab width L2 of the precast floor slab 2 having the loop joint 5, The number of floor slabs can be reduced, and the required steps for slab erection can be shortened.

When practicing the present invention, the precast floor slab 2 may be a floor slab in which a joint is provided at the upper and lower portions in the thickness direction on one end side in the bridge axis direction.
Further, when the present invention is carried out, when a plurality of reinforcing bars 9 are simultaneously handled and supported by the upper joint reinforcing bar 5a or the lower joint reinforcing bar 5b, the plurality of reinforcing reinforcing bars 9 are temporarily bound by a steel wire or the like. Thus, the temporary joint 16 may be supported by the upper joint rebar 5a or the lower joint rebar 5b. In this case, after removing the temporary binding with the steel wire and the temporary holder 16, the reinforcing reinforcing bars 9 may be deployed in the bridge axis direction.
The number of reinforcing bars 9 arranged in the temporary storage groove 15 may be one or a plurality of reinforcing bars 9 such as two or four, and the reinforcing bars 9 arranged in one temporary storage groove 15. The number of reinforcing bars 9 may be different from the number of reinforcing bars 9 arranged in the other temporary storage groove 15.
In the figure, reference numeral 18 denotes a convex portion provided at a position corresponding to the girder on the lower side of the floor slab 2.

1 Digit 2 Precast slab (Precast concrete slab)
3 Steel tubular body 4 Curable material (concrete)
5a Upper joint rebar 5b Lower joint rebar 5c Loop joint 6 End surface (inclined surface or flat surface)
7 Overhang support 8 Buffer layer 9 Reinforcing bar 10 Crimp grip (end band)
11 End face of upper floor slab 12 End face of lower floor slab 13 Step 14 Filling part between floor slabs (connecting part)
DESCRIPTION OF SYMBOLS 15 Temporary storage accommodation groove | channel 16 Temporary holding tool 18 Protruding part 20 Precast concrete floor slab main body 21 Loop-shaped rebar or loop strip steel plate 22 Long rebar 23 Short rebar 24 Support member 25 Strut 26 Obstacle

Claims (4)

  In the precast floor slab, the upper joint reinforcing bars and the lower joint reinforcing bars extending in the bridge axis direction from the precast floor slab body are arranged at intervals in the vertical direction, and the upper joint reinforcing bars are provided with a plurality of intervals in the direction perpendicular to the bridge axis. The upper floor slab end surface of the bridge slab body end of the floor slab body at the base end of the overhanging side of the bottom slab is lower than the end of the bottom floor slab of the bridge slab end of the floor slab body at the base end of the bottom joint A plurality of upper joints are provided so as to be displaced closer to the center part in the bridge axis direction, and provided with a stepped portion extending in a direction perpendicular to the bridge axis between the end face of the upper floor slab and the end face of the lower floor slab. The bridge shaft perpendicular direction characterized in that a temporary storage housing groove for reinforcing reinforcing bars is formed by the base end portion of the reinforcing bar and the step portion in the bridge axis direction in the precast slab. Reinforcing steel bars Precast slab with every receiving groove.   The stepped portion is a stepped portion having an inclined upper surface or a flat upper surface so as to be opposed to the lower surface on the proximal end side of the upper joint reinforcing bar with a space therebetween, and the stepped portion on the inclined upper surface or the flat upper surface The bridge according to claim 1, wherein one end side is connected to the lower floor slab end surface, and the other end side of the inclined upper surface or flat upper surface is connected to the upper floor slab end surface. Precast floor slab with reinforced reinforcing bar temporary storage groove in the direction perpendicular to the axis.   One or more reinforcing bars in the direction perpendicular to the bridge axis are arranged in the temporary storage groove in the precast floor slab with the reinforcing bar temporary storage groove in the direction perpendicular to the bridge axis according to claim 1 or 2, A precast floor slab that temporarily holds reinforcing bars in the direction perpendicular to the bridge axis, which is temporarily held by a temporary suspension provided on the upper joint reinforcing bars.   The precast slab temporarily holding the reinforcing bars in the direction perpendicular to the bridge axis according to claim 3 is arranged across the girders spaced in the direction perpendicular to the bridge axis and one of the precast slabs adjacent in the bridge axis direction. One or a plurality of reinforcing bars in the direction perpendicular to the bridge axis temporarily held on the upper joint reinforcing bar side or the lower joint reinforcing bar side are developed to bind the reinforcing reinforcing bar and the joint reinforcing bar, and the other precast One or more reinforcing bars in the direction perpendicular to the bridge axis temporarily held on the floor slab are deployed on either the upper joint reinforcing bar side or the lower joint reinforcing bar side to bind the reinforcing bar and the joint reinforcing bar. A precast floor slab installation method.

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