JP3415271B2 - Precast floor slab joint structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast floor slab joint structure applied to the construction of bridges and the like.

[0002]

2. Description of the Related Art At present, as a method for constructing a bridge, a precast floor slab consisting of a reinforced concrete slab and a thin steel plate pasted on the lower surface of this reinforced concrete slab is produced in advance in a factory, and these are produced on site. Generally, a construction method in which a plurality of precast slabs are juxtaposed on a bridge girder and concrete is cast into joints to fix the bridge to the bridge girder to form a roadbed is widely adopted.

The structure of the precast floor slab used in such a construction method will be described with reference to FIG. In the figure, reference numerals 1 and 2 are adjacent precast floor slabs, which are placed on the bridge girder 3. Precast floor slab 1
Has a structure in which two unit floor slabs 4 and 5 are connected with a gap 6. Each unit floor slab 4 or 5 has a structure in which a thin steel plate 8 called a skin plate having an upper surface welded with a dowel 7 is attached to the lower surface of a reinforced concrete plate 9. Here, a step portion 9a is formed in the reinforced concrete plate 9, and an end portion 8a of the skin plate 8 projects below the step portion 9a. A backing plate 10 is welded to the lower surface of the end 8a of the skin plate 8. The reinforced concrete slab 9 is composed of reinforcing bars 11 and 12 arranged in a grid pattern and a concrete slab 13. The reinforcing bar 11 is formed by projecting an end portion 14 from an end surface 9 b of the reinforced concrete plate 9. Further, the connecting member 15 and the reinforcing bar 12 are bridged in the gap 6 between the unit floor slabs 4 and 5.

The production of such a precast floor slab 1 is as follows.
On the upper surface of the skin plate 8, attach the dowel 7 to one end 8a.
After the backing metal 10 is welded to the lower surface of, the at least the lower surface of the skin plate 8 and the lower surface of the backing metal 10 are painted or plated by, for example, a method of dipping. Next, prepare two such skin plates 8 and attach them to the side surface 1.
After arranging with the gap 6 provided between 6 and 17, the skin plate 8 and 8 is used as a part of the mold to form a mold, and the connecting member 6 and the reinforcing bars 11 and 12 are arranged at predetermined positions. Then, concrete is filled in the formwork so that the concrete plate 13 has a predetermined thickness. After the concrete is solidified, the form is removed and the precast floor slab 1 is completed.

The roadbed is formed by sequentially connecting the precast floor slabs 1 having the above-mentioned construction along the bridge girders 3. A method for connecting the precast floor slabs at this time will be described with reference to FIGS. 4 and 5. In FIG. 4, the precast floor slab 2 is already fixed on the bridge girder 3 via the seal rubber 18. The next precast floor slab 1 will be connected in front of this precast floor slab 2. As a procedure of connection, when the precast floor slab 1 is installed at a predetermined position, the precast floor slab 1 remains as it is,
The ends 14, 20 of the second reinforcing bars 11, 19 collide with each other,
First of all, the end portions 1 of the reinforcing bars 11 and 19 will be an obstacle to work.
Bend all 4 and 20 upwards. Then, the precast floor slab 1 is made to enter the stat dowel 21 formed on the bridge girder 3 into the gap 6 formed in the precast floor slab 1, and the reinforced concrete slab 22 of the existing precast floor slab 2 is It is placed on the bridge girder 3 so as to form a space 23 between the end face 22b and the end face 9b of the reinforced concrete slab 9 of the precast floor slab 1 facing the end face 22b. At this time, the skin plate 24 of the precast floor slab 2
The back metal 25 attached to the precast floor slab 1,
2 of the respective skin plates 8, 24 at the ends 8a, 2
Try to block the joint between 4a.

Next, as shown in detail in FIG. 5, on the upper surface of the backing plate 25 attached to the precast floor slab 2, the gap between the skin plates 8 and 24 of the precast floor slabs 1 and 2, respectively. Molten metal as a welding material is poured into 26 to connect the skin plates 8 and 24.
As a result, a rigid connection between the skin plates 8 and 24 is achieved, and the connection strength between the precast floor slabs 1 and 2 is secured. After that, the precast floor slabs 1 and 2 rebars 11 and 1
The end portions 14 and 20 of 9 are returned straight, the required length is wrapped, the side portion of the space portion 23 is closed (not shown), and then the space portion 23 is concrete-placed, and the precast floor slab 1 2 is completed. At this time, rebar 11,1
The lap portion of 9 is embedded in concrete.

[0007]

By the way, in the connection of the precast floor slabs 1 and 2, since the molten metal is poured into the gap 26 on the upper surface of the backing metal 25 of the precast floor slab 2, the heat is applied to the backing metal. It is transmitted to the lower surface 25a of gold.
Even if the lower surface of the skin plate 8 and the lower surface of the backing plate 25 are coated at the time of factory shipment, the backing plate lower surface 25a
The surrounding paint or plating will be damaged by the heat of the molten metal. Therefore, there is a problem in that it is necessary to repaint the backing metal lower surface 25a after the completion of connection of the precast floor slabs 1 and 2. Since the backing metal lower surface 25a is the lower surface of the roadbed, it is difficult to paint, which is one of the factors that reduce the construction efficiency of the precast floor slab.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a joining structure for a precast floor slab that does not require repainting after construction and has good construction efficiency.

[0009]

In order to solve the above problems, the present invention employs the following configurations. That is, in the joining structure of the precast floor slabs according to claim 1, a plurality of precast floor slabs having skin plates made of thin steel plates attached to the lower surface of the reinforced concrete slab are juxtaposed, and between the end faces of the reinforced concrete slabs of each precast slab. A space portion is formed, the skin plate end portion of each precast floor slab is projected along the lower surface of the space portion, and a reinforcing bar is projected from the end surface of the reinforced concrete plate of each precast floor slab, and the lower surface of the skin plate end portion. A backing metal that closes the joint between these skin plate ends is placed between
In a joint structure of a precast floor slab in which concrete is cast in a state where the reinforcing bars are embedded in the space portion, a connection projecting toward the opposite skin plate end portions on the upper surface of the skin plate end portion. The auxiliary steel plates for welding are welded, and the tip portions of these auxiliary steel plates for connection are welded to each other. Further, in the joining structure of the precast floor slab according to claim 2, in the joining structure of the precast floor slab according to claim 1, a heat insulating material is interposed between the auxiliary steel plate for connection and the end surface of the skin plate. It is characterized by being.

[0010]

In the joint structure of precast floor slabs according to the first aspect of the present invention, when connecting the adjacent precast floor slabs, the connecting auxiliary steel plate attached to the skin plate is welded at its tip. This achieves a rigid connection between the skin plates of adjacent precast floor slabs, eliminating the need to use molten metal to connect the skin plates,
Therefore, the coating or plating on the lower surface of the skin plate and the lower surface of the backing metal is not damaged by the heat of the molten metal,
It is not necessary to repaint the bottom surface of the skin plate and the bottom surface of the backing plate. In the joint structure of the precast floor slab according to claim 2, since the heat during welding of the auxiliary connecting steel plate is blocked by the heat insulating material interposed between the auxiliary connecting steel plate and the end surface of the skin plate, There is no paint or plating damage on the bottom surface of the skin plate and the backing metal,
There is no need for repainting.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a roadbed of a bridge to which the present invention is applied. The configuration of FIG. 1 differs from the configuration of FIG. 4 which is a conventional example in that precast floor slabs 27 and 28 are connected with auxiliary steel plates 29 for connection, respectively. , 30 are the ends 8 of the skin plates 8, 24
Since only the points are provided on the upper surface side of a and 24a and the other configurations are the same as those in FIG. 4, the same reference numerals are given to the same portions, and the description thereof will be omitted. FIG. 2 is a diagram showing in detail the auxiliary steel plates 29, 30 for connection in FIG.
In the figure, connecting auxiliary steel plates 29 and 30 are the upper surfaces 31 of the end portions 8a and 24a of the skin plates 8 and 24, respectively.
They are welded at 32 and are provided so as to project toward the facing skin plate end portions 24a and 8a, respectively. A plurality of such connecting auxiliary steel plates 29 and 30 are provided along the ends 8a and 24a of the skin plates 8 and 24, respectively.

The precast floor slab 27 is manufactured by using the dowel 7 on the upper surface of the skin plate 8, the backing plate 10 on the lower surface of one end 8a, and the connecting auxiliary steel plates 29 on the upper surfaces of both ends 8a.
After welding, the entire surface of the skin plate 8, the dowel 7, the backing plate 10 and the auxiliary steel plate 29 for connection is galvanized by dozing. Two such skin plates 8 are prepared, and the work after arranging them with the gap 6 provided between the side surfaces 16 and 17 is performed in the same procedure as the conventional example.

Next, a method of forming a roadbed to which the joining structure of the precast floor slab of the present invention is applied will be described. The roadbed is formed by the precast floor slabs 27, 2 having the above-mentioned configuration.
This is done by sequentially connecting 8 along the bridge girder 3.
A method of connecting the precast floor slabs 27 and 28 at this time will be described with reference to FIGS. 1 and 2. In FIG. 1, a precast floor slab 28 is already fixed on the bridge girder 3 via a seal rubber 18. This precast floor slab 28
The next precast floor slab 27 will be connected in front of. As a connecting procedure, the end portions 1 of the reinforcing bars 11 and 19 are connected.
The work of bending all 4 and 20 upward and placing the precast floor slab 27 at a predetermined position is the same as the conventional example.

As shown in detail in FIG. 2, the auxiliary steel plates 29, 30 for connection are respectively the skin plate 8,
By welding the tip portions 33 and 34 protruding from 24 to each other, a rigid connection between the adjacent skin plates 8 and 24 is achieved, and a connection strength between the adjacent precast floor slabs 27 and 28 is secured. After that, precast floor slab 2
After the end portions 14 and 20 of the reinforcing bars 11 and 19 of 7 and 28 are returned straight, the required length is wrapped, and the side portion of the space portion 23 is closed (not shown), concrete is poured into the space portion 23. Then, the connection of the precast floor slabs 27 and 28 is completed. At this time, the lap portions of the reinforcing bars 11 and 19 are embedded in the concrete.

When the precast floor slabs 27 and 28 are connected, the tip portions 33 and 34 of the connecting auxiliary steel plates 29 and 30 are welded to each other as described above, and the adjacent skin plates 8 and
A rigid connection between 24 is achieved. This ensures the connection strength between the adjacent precast floor slabs 27, 28,
The work of pouring the molten metal between the skin plates 8 and 24 is no longer necessary. Therefore, the zinc plating on the lower surface of the skin plate 8 and the lower surface of the backing metal 25 is not damaged,
The work of applying repainting is unnecessary, and construction efficiency improves.

In the above embodiment, the backing metal 25
Was welded to the skin plate 24, but the backing metal 25, which was previously welded to the dowel 36 shown in FIG.
The backing metal 25 may be attached by entwining.
At this time, the lower surface of the backing metal 25 is galvanized after the welding of the dowel 36.

Further, in the above embodiment, the auxiliary steel plates 29, 30 for connection and the end faces 8a, 2 of the skin plates 8, 24 are formed.
The effect of the present invention can be more remarkably realized by interposing the heat insulating material 37 made of asbestos between 4a and 4a. At this time, as shown in FIG. 3, heat at the time of welding the tip end portions 33, 34 of the connecting auxiliary steel plates 29, 30 is cut off by the heat insulating material 37, so that the lower surface of the skin plates 8, 24 and the backing plate. There is no damage to the zinc plating on the lower surface of the gold 25, and there is no need to repaint.

Although zinc plating is shown as an example of coating or plating in the above embodiments, the present invention is not limited to zinc plating, and various coatings or plating can be applied. Although asbestos is exemplified as the heat insulating material, the heat insulating material is not limited to asbestos, and various heat insulating materials can be used.

[0019]

According to the joining structure of precast floor slabs as claimed in claim 1, when the adjacent precast slabs are connected, the skin plates of the adjacent precast slabs are stiffened by welding the tips of the auxiliary steel plates for connection. Since the bond is achieved and the connection strength of the precast floor slab is ensured, it is not necessary to use molten metal to bond the skin plate, therefore
Since the coating or plating on the lower surface of the skin plate and the lower surface of the backing metal is not damaged by the heat of the molten metal, and there is no need to re-paint, a precast floor slab with good construction efficiency can be obtained. Further, according to the joint structure of the precast floor slab according to claim 2, by using the heat insulating material just below the welded portion, the coating or plating on the lower surface of the skin plate and the lower surface of the backing metal is not damaged by the influence of welding. None at all
A higher effect can be obtained.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention and is a perspective view showing a roadbed of a bridge to which the present invention is applied.

FIG. 2 is a perspective view showing a main part of a roadbed of the bridge shown in FIG.

FIG. 3 is a perspective view showing another example of the main part of the roadbed of the bridge shown in FIG. 1.

FIG. 4 is a perspective view showing a conventional example of a roadbed of a bridge.

5 is a perspective view showing a main part of the roadbed of the bridge shown in FIG. 4. FIG.

[Explanation of symbols]

8 ... Skin plate, 8a ... Skin plate end, 9 ...
Reinforced concrete plate, 9b ... Reinforced concrete plate end surface,
10 ... Backing metal, 11 ... Reinforcing bar, 19 ... Reinforcing bar, 22 ... Reinforced concrete plate, 22b ... Reinforced concrete plate end face, 23
... space, 24 ... skin plate, 24a ... skin plate end, 25 ... backing metal, 27 ... precast floor slab, 2
8 ... Precast floor slab, 29 ... Auxiliary steel plate for connection, 30 ...
Connection auxiliary steel plate, 33 ... Tip part, 34 ... Tip part, 37 ...
Insulation.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-57702 (JP, A) JP-A-4-300080 (JP, A) Actual opening Sho-58-33501 (JP, U) Actual opening Sho-57- 41911 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) E01D 19/12 E01D 1/00 E04B 5/00 E04B 1/60 503

Claims (2)

(57) [Claims] 1. A plurality of precast floor slabs each having a skin plate made of a thin steel plate attached to the lower surface of a reinforced concrete slab are juxtaposed, and a space is formed between the end faces of the reinforced concrete slabs of each precast floor slab. The end of the skin plate is projected along the lower surface of the space, the reinforcing bar is projected from the end surface of the reinforced concrete slab of each precast floor slab, and the joint between the skin plate ends is located between the lower surfaces of the skin plate end. In a joint structure of a precast floor slab in which a backing metal that closes is arranged, and concrete is cast in a state where the reinforcing bars are embedded in the space portion, the skin plates facing each other on the upper surface of the skin plate end portion. The connecting auxiliary steel plates protruding toward the end are welded, and the tips of these connecting auxiliary steel plates are welded to each other. Precast floor slab joint structure characterized by being 2. The precast floor slab joining structure according to claim 1, wherein a heat insulating material is interposed between the connection auxiliary steel plate and the skin plate end surface. Construction.