JP2001279853A - Synthetic floor slab and half precast floor slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for manufacture and improve work efficiency while maintaining a shearing endurance force equal to that of a conventional synthetic floor slab. SOLUTION: This synthetic floor slab 1 is constituted by arranging a main reinforcing bar 4 and a distributing bar 5 on a top face of a reinforcing member welded on a surface side of a bottom steel plate 2 and then placing concrete 7. An expand metal 3 is used as the reinforcing member in the direction of the main reinforcing bar 4 so that the member can be held in the oblique direction by the expand metal used without necessitating a device exclusively for assembly, the number of reinforcing members is greatly reduced because a spacer is not required in particular, and work efficiency is improved. Moreover, since the filling property of concrete can be ensured, the shearing strength of the floor slab and the synthetic effect of concrete and the bottom steel plate can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a composite slab or a half precast slab used for a road bridge, for example.

[0002]

2. Description of the Related Art For example, RC slabs which have been conventionally used as floor slabs for road bridges have been used for 10 years under heavy traffic in recent years.
Punching shear failure has begun to occur in a few years.
In order to cope with this punching shear failure, it was necessary to shear-strengthen the RC slab, and repair and replacement of the slab required a great deal of labor and cost.

[0003] In recent years, a composite slab with a form steel plate has been developed through an RC slab with a form steel plate using truss reinforcing steel, and the fatigue durability under heavy traffic has been improved. It has become. The composite slab using the steel plate as a form is reinforced by ribs or dowels, truss bars, or the like to increase the shear durability of the slab.

[0004]

However, in the above-mentioned composite slab, the reinforcing material such as ribs, dowels, and truss bars adopt a structure welded to the bottom steel plate of the slab. Since the number of members is large, there is a problem that the time required for manufacturing is increased due to an increase in the amount of welding, and the cost must be increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to reduce the time required for production and improve work efficiency while maintaining the same shear durability as a conventional synthetic slab. It is an object of the present invention to provide a composite slab or a half-precast slab that can be used.

[0006]

In order to achieve the above-mentioned object, in the composite slab or the half precast slab of the present invention, as a reinforcing material of the composite slab or the half precast slab, the expanded slab is expanded in the direction of the main reinforcing bar. It is decided to use metal. And by doing so, the number of reinforcing members is reduced while ensuring the concrete filling property,
The shear strength of the floor slab and the effect of combining the concrete and the bottom steel plate can be secured.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Expanded metal is sold as a mold steel.
The bending process alone does not require any particular processing or assembly, and the diagonal member of the expanded metal exerts a reinforcing effect on the improvement of the shear strength, so it can be said that the reinforcing material is excellent in economic efficiency. In addition, if an expanded metal having an appropriate size is selected, there is no problem in filling the aggregate of the concrete. The composite effect of the concrete slab and the bottom steel plate can be obtained by welding the expanded metal to the bottom steel plate to prevent the slab from slipping.

The present invention has been made from this point of view. The composite floor slab of the present invention is a concrete slab in which a main reinforcing bar and a distribution bar are arranged on the upper surface of a reinforcing material welded to the surface side of a bottom steel plate. In the composite floor slab to be cast, as the reinforcing material,
Expanded metal is used in the direction of the main rebar.

Further, the half precast slab of the present invention is a half precast slab in which a main reinforcing bar and a distribution bar are arranged on an upper surface of a reinforcing material erected on the surface side of the precast slab, and then concrete is poured. As the reinforcing material,
About half of the height is embedded in the precast slab, and expanded metal is used in the direction of the main reinforcing bar.

In the composite slab and the half precast slab of the present invention, the expanded metal is used as the reinforcing material in the direction of the main reinforcing bar, so that the number of reinforcing members can be greatly reduced. Moreover, since expanded metal is used and the filling property of concrete can be ensured, the shear strength of the floor slab and the effect of combining concrete with the bottom steel plate can also be ensured.

In the composite floor slab and the half precast slab of the present invention, the expanded metal used as a reinforcing bar has one or two or more expanded metals, and the upper side is the top. A material bent into a triangular shape, a material in which two expanded metals are formed in a triangular shape having an upper side as an apex, a material in which one expanded metal is arranged in a vertical direction, or the like is used.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The synthetic floor slab of the present invention will be described below with reference to the embodiments shown in FIGS. FIG. 1 is a cross-sectional view of a road bridge using the composite floor slab of the present invention as viewed from the front side, and FIG. 2A is a diagram showing a state before the main reinforcing bars, distribution bars and concrete are cast in FIG. , (B) is an enlarged view of a part a of (a), FIG. 3 is a sectional view taken along line AA of FIG. 2 (a), FIG. 4 is a sectional view taken along line BB of FIG. 3, and FIG. 6A and 6B are sectional views showing another embodiment of FIG.

1 to 5, reference numeral 1 denotes a composite floor slab of the present invention, which comprises a bottom steel plate 2, expanded metal 3, main reinforcing bars 4, distribution bars 5, and flat ribs 6. Of these, the bottom steel plate 2 is stiffened by flat ribs 6 and concrete 7
It is used as a formwork for placing concrete and serves as a lower main reinforcing bar after the floor slab is put into service.

The expanded metal 3 serves as a dowel member for connecting the bottom steel plate 2 and the concrete 7, and for example, as shown in FIG. 4 and FIG. The bottom plate 2 is bent and welded to the surface side of the bottom steel plate 2 so as to be in the direction of the main reinforcing bar 4, and serves to combine the bottom steel plate 2 and the concrete 7. In the embodiment shown in FIGS. 1 to 5, one expanded metal 3 forms one reinforcing surface. However, one expanded metal 3 forms two or more reinforcing surfaces. 6 (a), one in which one expanded surface is formed by two expanded metals 3 as shown in FIG. 6 (a), or one as shown in FIG. 6 (b).
Needless to say, a reinforcing surface may be formed by arranging a plurality of expanded metals 3 vertically, for example.

The height of the expanded metal 3 welded to the front side of the bottom steel plate 2 is adjusted during bending according to the arrangement height of the main reinforcing bars 4 and the distribution bars 5. From the above,
In the synthetic floor slab 1 of the present invention, the expanded metal 3 also has a role as a substitute for the spacer when the main reinforcing bars 4 and the distribution bars 5 are arranged.

As shown in FIG. 3, the bottom surface of the composite floor slab 1 of the present invention forms an opening 9 on the main girders 8, 8 which are erected at predetermined intervals. The flange 8a of the main girder 8 and the composite floor slab 1 of the present invention are connected by the expanded metal 3 by the hardening of the concrete 7 by casting.

At this time, in this embodiment, for example, an angle iron 10 is welded to the bottom steel plate 2 over the opening 9 on the main girder 8 in the same horizontal plane as the bottom steel plate 2 as shown in FIG. The continuity of the bottom steel plate 2 is maintained. Although not shown, a bolt is screwed into the angle iron 10 and the amount of screwing of the bolt is adjusted so that the angle iron 1 can be installed when the floor slab is erected.
It is desirable to be able to set 0 to a predetermined height.

Since the synthetic floor slab 1 of the present invention is divided into blocks and transported to the site, the width of the blocks is set to a size that can be transported, and the standard for land transportation is, for example, 3 m. As the joint 12 between the blocks of the composite floor slab 1, for example, a butt joint structure using a high-strength bolt for friction joining or a torcia-type high-strength bolt is adopted. In addition, 11 in FIG.
Indicates an asphalt pavement on the surface side of the concrete 7.

In the composite slab 1 of the present invention, since the expanded metal 3 is used as the reinforcing material in the direction in which the main reinforcing bars 4 are arranged, a conventional composite slab using a reinforcing material such as a rib, a dowel or a truss bar is used. , The number of reinforcing members can be significantly reduced. Further, since the expanded metal 3 is used, the filling property of the concrete 7 can be secured, and the shear strength of the floor slab and the effect of combining the concrete 7 and the bottom steel plate 2 can be secured.

Although illustration is omitted, in the half precast slab, the expanded metal is buried in the slab of the precast portion used as a substitute for the formwork so that about half of its height is cast in place. Can be combined with the floor slab.

[0021]

As described above, in the composite slab and the half precast slab of the present invention, expanded metal is used as the reinforcing material in the direction of the main reinforcing bar, and therefore, a dedicated assembly device such as a truss bar is used. The expanded metal to be used can be bent without requiring a metal.

The composite slab and the half precast slab of the present invention do not require a spacer or the like, and are reinforced in comparison with conventional composite slabs using reinforcing materials such as ribs, dowels, and truss bars. Since the number of members can be greatly reduced, work efficiency is improved.

Further, in the composite slab and the half precast slab of the present invention, since the expanded metal is used, the filling property of the concrete can be ensured, so that the shear strength of the slab and the effect of combining the concrete and the bottom steel plate can be obtained. Can also be secured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view as viewed from the front side of a road bridge using a composite floor slab of the present invention.

2 (a) is a view showing a state before placing a main reinforcing bar, a distribution bar and concrete in FIG. 1, and FIG. 2 (b) is a view of FIG.
It is a part enlarged view.

FIG. 3 is a view taken along the line AA in FIG. 2 (a).

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a sectional view taken along line CC of FIG. 3;

FIGS. 6A and 6B are views showing another embodiment of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite floor slab 2 Bottom steel plate 3 Expanded metal 4 Main reinforcing bar 5 Distribution bar 7 Concrete

Claims (5)

[Claims] 1. A composite floor slab in which a main reinforcing bar and a distribution bar are arranged on the upper surface of a reinforcing member welded to the surface side of a bottom steel plate and then concrete is cast, wherein the reinforcing member is in the direction of the main reinforcing bar.
A synthetic floor slab characterized by using expanded metal. 2. A half precast slab in which a main reinforcing bar or a force bar is arranged on an upper surface of a reinforcing material erected on the surface side of the precast slab and then concrete is cast, wherein the precast slab is used as the reinforcing material. A half precast floor slab characterized by using expanded metal in the direction of the main rebar, with about half of the height embedded. 3. The composite floor slab according to claim 1, wherein the expanded metal to be used is bent into a triangular shape having an upper side as an apex. 4. The composite slab according to claim 1, wherein the expanded metal to be used is formed in a triangular shape having two vertices on the upper side. . 5. The composite floor slab according to claim 1, wherein one of the expanded metals to be used is arranged vertically, and the half precast floor slab according to claim 2.