JP2671197B2 - Reinforced concrete precast floor slab - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a precast floor slab for a bridge structure.

[0002]

2. Description of the Related Art For bridge decks, a formwork is manufactured on site, steel bars are placed on this formwork, and on-site cast floor slabs are used to place concrete. There is a precast floor slab that is made by placing reinforcing bars on the formwork, pouring concrete into it, and then bringing it to the site.

Since the precast floor slab does not require formwork, rebar arrangement, concrete placing, etc. on the site, there is a great advantage that the traffic regulation can be greatly shortened in the replacement and repair of the existing floor slab.

Precast floor slabs are usually manufactured at the factory so as to be suitable for the situation of the site such as bridge structure and working conditions.
It is divided into appropriate sizes in the axial direction and width direction of the bridge. The precast floor slabs divided into appropriate sizes are placed on the girders, and are connected to each other in the axial direction and the width direction of the bridge to be integrated. Connection of the precast floor slab in the width direction of the bridge is usually performed by connecting the upper rebar embedded in the precast slab. Specifically, as shown in FIG. 6, one of the precast floor slabs A1 and A2 adjacent to each other on the main girder C is used.
1. Cut out the end portion of No. 1 and in this cutout portion B, the upper rebar D1
Is extended and positioned, the connecting rebar E is connected to the upper rebar D2 of the other precast floor slab A2 using the joint G, and then concrete is placed in the notch B. The lower reinforcing bars F1 and F2 are not connected.

In the connection of the precast floor slabs thus made, since the lower reinforcing bars are not connected, there is a difficulty in the integration, and much work is required and the workability is not good. Therefore, it would be very convenient if one precast floor slab could be manufactured in the width direction of the bridge. However, there are some problems in providing one precast floor slab in the width direction of the bridge.

The bridge slab, whether it is a cast-in-place slab or a precast slab, usually faces the outside in the width direction of the road with the middle main girder on which it is placed as a boundary. Each has a drainage gradient. The magnitude of this gradient is
It depends on the length of the bridge deck in the width direction of the road and the number of girders.

This presents a major disadvantage to factory-made precast floor slabs. First of all, when trying to make a precast slab that is one in the width direction of the road, in each case, a large steel form frame considering the gradient toward the outside with the middle as the boundary of the site situation. Since it takes a lot of days to make the formwork, and the steel formwork made is amortized only by the individual precast floor slabs, the formwork cost is very high and economical. Has a disadvantage.

[0008]

DISCLOSURE OF THE INVENTION The present invention is to solve the problems of the economic disadvantage of the number of days and the cost of the formwork required for producing the formwork in the above-mentioned precast floor slab, and to appropriately cope with the drainage gradient. It provides a precast floor slab that can be used.

The present invention solves the above problems and provides a precast floor slab capable of appropriately responding to a drainage gradient. Therefore, the constituent requirements of the precast floor slab are the floors adjacent to each other with a space in the main girder direction. In the road width direction of the plate member, the upper reinforcing bars are continuously arranged, the adjacent floor slab members are connected, and the lower reinforcing bars are arranged on each of the adjacent floor slab members without overlapping in the space. It is characterized by that.

[0010]

Since the adjacent floor slab members have a space and are continuous only by the upper reinforcing bar, it becomes possible to bend with this space as a boundary. It can follow the drainage gradient.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a reinforced concrete precast floor slab with three main girders, and FIG. 2 is an enlarged cross-sectional view of the bridge axial direction of FIG. The precast floor slab 1 is formed by pouring concrete in a steel mold in such a manner that a space 2 is provided in the main girder direction at a position corresponding to the main girder in the middle. When pouring concrete, the upper rebar 3 and the lower rebars 4a and 4b are previously arranged in the steel form. The upper reinforcing bars 3 are concrete members 1a, 1 with the space 2 in between.
are arranged consecutively in the width direction of the road to connect b,
The lower rebars 4a and 4b are arranged on the floor slab members 1a and 1b, respectively, and are arranged in the space 2 so as not to be continuous with each other.
In this embodiment, the overlapping portions of the lower reinforcing bars 4a and 4b are formed in a key shape, but it goes without saying that they may be L-shaped or linear.

Here, the formwork forming the precast floor slab does not need to take into consideration the magnitude of the drainage gradient from the middle girder-corresponding portion toward both outer sides, so that the bottom surface of the precast floor slab is not considered. Since it is formed so as to be flat, it is possible to manufacture precast floor slabs of various sizes simply by changing the positions of the side plates.

In this way, as a whole, the upper reinforcing bars 3 are continuously arranged in the road width direction of the adjacent floor slab members 1a and 1b having the space 2 in the main girder direction, and the adjacent floor slab members 1 are arranged.
a and 1b are connected and adjacent floor slab members 1a, 1
A reinforced concrete precast floor slab is formed in which the lower reinforcing bars 4a and 4b are arranged in the space 2 so as not to be continuous with each other and are superposed on each other.

FIG. 3 is a perspective view showing an example in which the precast floor slab according to the present invention is installed on three main girders, and FIG. 4 is an enlarged cross-sectional view of the main part thereof. In the figure, first, the precast floor slab 1 is placed on each main girder 5 via a haunch member 6 made of L steel material integrated on both sides of the flange by welding or the like. Here, the space 2 of the precast floor slab 1 is located in the middle main girder 5 and imparts a drainage gradient to the floor slab members 1a, 1b toward the outside in the bridge width direction. Floor slab member 1a,
Since 1b has a space 2 and is continuous only by the upper reinforcing bar 3, it is possible to follow the drainage gradient. Then, concrete is poured into the space 2 to integrate the precast floor slab 1 and the main girder 5. In this embodiment, the ground covering 9 is processed separately and attached to both sides of the precast floor slab 1. In addition, 7 is a sponge packing and 8 is a stud bolt.

FIG. 5 is a schematic view showing an embodiment in which the present invention is applied to a bridge having five main girders. The precast floor slab 1 is formed with a drainage gradient toward the outside with the space 2 in the upper equivalent part of the central main girder 51 as a boundary. Here, the method of manufacturing the precast floor slab 1 and the method of placing the precast floor slab 1 on the girders 51, 52, 53 are the same as those in the above-described embodiment.

[0016]

Since the present invention has been made as described above,
It has the following effects. (1) Since the adjacent floor slab members have a space and are continuous only by the upper reinforcing bar, it becomes possible to bend with this space as a boundary, in the opposite direction of the adjacent floor slab members or in a different size. Can follow the drainage gradient of. (2) Since adjacent floor slab members have a space and are continuous only by the upper reinforcing bar, bending is possible with this space as a boundary, so the formwork of one precast floor slab is created in the width direction. Also in this case, it is not necessary to consider the drainage gradient.
Therefore, the mold frame may be formed flat along the bottom surface of the precast floor slab, so that it is possible to manufacture various sizes of precast floor slabs simply by changing the positions of the side plates. Therefore, the manufacturing period of the mold can be shortened and the cost can be reduced. (3) Since the lower rebars located in the spaces of the adjacent floor slabs are overlapped with each other, the concrete is cast in the spaces to strengthen the integrity. (4) Adjacent floor slab members are continuous in the width direction of the bridge by the upper reinforcing bars, so the labor of connecting the precast floor slabs divided in the width direction of the bridge is omitted. be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a precast floor slab according to the present invention.

FIG. 2 is an enlarged cross-sectional view of FIG. 1 viewed in the bridge axis direction.

FIG. 3 is a perspective view showing an example in which a precast floor slab according to the present invention is installed on three main girders.

FIG. 4 is an enlarged sectional view of a main part of FIG.

FIG. 5 is a schematic cross-sectional view showing an example in which a precast floor slab according to the present invention is installed on five main girders.

FIG. 6 is a cross-sectional view showing a conventional example of a method of connecting precast floor slabs that are divided in the bridge width direction and adjacent to each other.

[Explanation of symbols]

 1 Brecast floor slab 1a Floor slab member 1b Floor slab member 2 Space 3 Upper rebar 4a Lower rebar 4b Lower rebar 5 Main girder

Claims (1)

(57) [Claims] 1. An upper reinforcing bar is continuously arranged in the road width direction of adjacent floor slab members having a space in the main girder direction to connect the adjacent floor slab members and to lower each adjacent floor slab member. A reinforced concrete precast floor slab characterized by arranging side reinforcing bars in the above-mentioned space so as not to be continuous with each other.