JPH0782991A - Concrete precast floor slab - Google Patents

Abstract

PURPOSE:To make lightweight a concrete precast floor slab by arranging a plurality of steel tie plates in parallel on a flat plate-like steel bottom plate at an interval, at the same time, providing a mesh between them, and filling concrete between the bottom plate and tie plates. CONSTITUTION:A plurality of tie plates 12 are arranged on the surface of concrete 15 in the opposite side of a bottom plate 11, so that cover concrete of the concrete 15 is not required for both sides. After that, specially, the strength is promoted to the geometrical moment of inertia while thinning it, the tie plates 12 are formed in the shape of a belt, so that resistance force against bending is further promoted effectively in the case thickness is increased. In the case a floor slab 10 is used upside down, the upper surface is covered with the bottom plate 11, so that the incursion of rain water into concrete is prevented. According to the constitution, the concrete precast floor slab can be lightweight, at the same time, the strength can be promoted, the floor slab of a bridge, etc., and construction of a bridge pier can be simplified because it is thinned, and construction efficiency can be promoted to reduce cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast concrete slab made of concrete for forming a floor by continuously connecting bridges in the girder direction.

[0002]

2. Description of the Related Art Conventionally, as a floor slab of this type, as shown in FIG. 4, a rectangular plate-shaped thin steel plate 2 having a large number of dowels 1 ... There is a structure in which the steel bars 2 and the concrete 4 are integrated by disposing the reinforcing bars 3 and placing concrete 4 on the top.

However, in the case of the floor slab as described above,
A so-called fog (d) between the upper surface and the reinforcing bar 3 is always required, and thus it is difficult to form a thin shape. In the case of a bridge, for example, this problem is not only thicker but also heavier, so that members such as bridge piers also need to be made larger, resulting in an increase in cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a concrete precast floor slab suitable for bridges and the like, which can be made thin but does not impair the strength.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and a plurality of flat plate-shaped steel bottom plates are provided on a flat surface slightly separated from the bottom plates. Between the books, steel strips arranged in parallel with each other at a predetermined distance, a mesh installed between the bottom plate and the strip plate in parallel with the bottom plate and the strip plate, and between the bottom plate and the strip plate. It is characterized in that it is provided with concrete that is poured into and filled with.

According to the second aspect of the present invention, a plurality of steel strips are provided in parallel at the position of the bottom surface of the floor slab in parallel with each other, and a steel strip is provided slightly apart from the strips and covers the upper surface of the floor slab. An upper bottom plate, a mesh installed between the upper bottom plate and the strip plate in parallel with the upper bottom plate and the strip plate, and concrete poured and filled between the upper bottom plate and the strip plate. Is characterized by.

[0007]

According to the concrete precast floor slab of claim 1, the bottom plate, the mesh, the concrete and the strip plate exert stress to support the bending load. Structurally, the strip is located on the surface of the concrete, and the fog on the strip is unnecessary, so that the weight and the strength can be reduced.

According to the concrete precast floor slab of claim 2, in terms of strength, it has the same action as the concrete precast floor slab, and
Since the upper bottom plate covers the upper surface of the floor slab, it is possible to prevent rainwater and the like from entering the inside.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In the figure, reference numeral 10 is a concrete precast floor slab of the first embodiment (hereinafter, simply referred to as floor slab), 11 is a bottom plate, 12 is a strip plate, 13 is a stud dowel, 14 is a mesh, 15 is concrete, 16 is a pipe dowel. Is.

The floor slab 10 is a rectangular slab, and a plurality of flat bottom plates 11 made of steel are arranged in parallel with each other on a plane slightly separated from the bottom plates 11. Steel strip 12 and these bottom 11 and strip 12
And a mesh 14 installed in parallel between the base plate 11 and the bottom plate 11, and a concrete 15 poured and filled between the bottom plate 11 and the strip plate 12.

The bottom plate 11 is a rectangular flat plate having the same shape as the surface direction of the floor slab 10, and a large number of stud dowels 13 arranged at equal intervals are vertically provided on the surface of the strip plate 12 side. The strip 12 is a long strip, and a plurality of strips 10 are provided.
Are evenly arranged in the width direction of the bottom plate 11 and are arranged parallel to the length direction of the bottom plate 11. The stud dowel 13
Is a steel cylinder or rod-shaped member, and each strip 1
2. A number of strips 12 are evenly arranged along the length direction
And the strip plate 1 in contact with the surfaces of the bottom plate 11 facing each other.
2 and the floor board 11 are held at a constant interval.

The mesh 14 is constructed by fixing main ribs 17 arranged along the length direction of the floor slab 10 and distribution muscles 18 arranged along the width direction of the floor slab 10 to each other. ing. A large number of main bars 17 are evenly arranged in the width direction of the floor slab 10, and are fixed to the upper surfaces of the force distribution bars 18 in a erected state. A large number of distribution muscles 18 are evenly arranged in the width direction of the floor slab 10 and are arranged in parallel with the installation surfaces of the bottom plate 11 and the strip 12 by welding to the side ends of the strip 12 of the stud dowel 13. Has been done.

Concrete 15 includes a bottom plate 11 and a strip plate 12.
And is filled between them by filling, and the stud dowel 13, the mesh 14, and the pipe dowel 16 are embedded and integrated with each other. The concrete 15 forms a surface flush with the outer surface of the strip 12. The pipe dowel 16 is a hollow cylindrical steel pipe and is vertically welded to the surface of the bottom plate 11 on the side of the strip plate 12. The welding position of the pipe dowel 16 is
It is the center of a quadrangle formed by four stud dowels 13 adjacent to each other.

The operation and effect of the floor slab 10 will be described below. Since the floor plate 10 includes the bottom plate 11 and the strip plate 12, the floor plate 10 is lighter than the conventional floor plate shown in FIG. Is high. That is, a plurality of strips 12 are provided on the opposite side of the bottom plate 11.
Is disposed on the surface of the concrete 15, so that fogging of the concrete 15 is not required on both sides, and therefore, although it is possible to reduce the thickness, it is possible to improve the proof stress particularly in the second moment of area. Further, since the strip 12 is strip-shaped, increasing the thickness can more effectively improve the resistance to bending, and can suppress the increase in cost associated with the use of steel material to a low level. .

From these facts, the floor slab 10 has the strip 12
Since it is possible to reduce the weight and improve the strength by the action of, for example, by applying it to a bridge, the floor slab thickness of the bridge can be reduced and the structural materials such as bridge piers that support the load can be simplified. It is possible to improve efficiency and reduce construction costs.

FIG. 3 shows a floor slab 20 according to a second embodiment of the present invention. The floor slab 20 has a structure in which the floor slab 10 of the first embodiment is turned upside down. The bottom plate 11 in is configured as the upper bottom plate 21.

According to this floor slab 20, the same operational effect as that of the floor slab 10 of the first embodiment is obtained, and since the upper surface is covered with the upper bottom plate 21, the ingress of rainwater or the like is prevented. As a result, the crack width is prevented from increasing due to the invading water, and the life is extended, and the cost for maintenance and the like is reduced.

[0018]

As described above, according to the first aspect of the present invention.
According to the concrete precast floor slab of claim 2, the weight is promoted while the strength is improved,
Particularly, it has an excellent effect that it can be made thin and is suitable for a bridge or the like. Further, particularly in the floor slab of claim 2,
Since the upper surface is covered with the upper bottom plate, the intrusion of rainwater and the like into the inside is prevented, and the increase of the crack width due to the intruding water is suppressed, which extends the life and reduces the cost of maintenance and the like.

[Brief description of drawings]

FIG. 1 is a partial perspective view of a first embodiment of the present invention.

FIG. 2 is a sectional view of the same embodiment.

FIG. 3 is a sectional view of a second embodiment of the present invention.

FIG. 4 is a side sectional view showing a conventional floor slab.

[Explanation of symbols]

 10, 20 Floor slab 11 Bottom plate 12 Strip plate 14 Mesh 15 Concrete 20 Floor slab 21 Top bottom plate

Claims (2)

[Claims] 1. A concrete precast floor slab that is joined to form a road surface slab of a bridge or the like, wherein a flat steel bottom plate and a plurality of predetermined spaces are provided on a plane slightly separated from the bottom plate. Steel strips that are spaced apart and arranged in parallel to each other, a mesh that is installed between the bottom plate and the strip plate in parallel with the bottom plate and the strip plate, and is placed and filled between the bottom plate and the strip plate. A precast floor slab made of concrete, which comprises: 2. A concrete precast floor slab that is joined to form a road surface slab of a bridge or the like, and a plurality of steel strips that are arranged in parallel at the position of the bottom surface of the floor slab, A steel upper bottom plate which is provided slightly apart from the plate and covers the upper surface of the floor slab, a mesh installed between the upper bottom plate and the strip plate in parallel with the upper bottom plate and the strip plate, and the upper bottom plate and the strip plate. A precast concrete slab made of concrete, which comprises a concrete poured into a space between the board and the plate.