JPH07119237A - Composite floor board - Google Patents

Abstract

PURPOSE:To surely integrate a steel plate with concrete, and insure rigidity of the steel plate. CONSTITUTION:A lattice-like rib 10 formed into squares out of lateral ribs 4 made of flat steel and longitudinal ribs 3 made of CT shape steel is arranged on a bottom steel plate 1. The lateral ribs 4 and the longitudinal ribs 3 are fitted in the slits of a plurality of pipe dowels 2 with slits arranged on the bottom steel plate 1, and crossed hereon. The bottom steel plate 1 and the pipe dowels 2, and, the pipe dowels 2 and the lateral ribs 4 and the longitudinal ribs 3 are respectively fixedly secured by welding. Concrete is placed while burying the the pipe dowels 2 and the lattice-like rib 10. The steel plate and the concrete are surely integrated through the lattice-like rib and the pipe dowels. The bottom steel plate is reinforced with the lattice-like rib so as to increase the rigidity. The bottom steel plate is welded with only the pipe dowels, and the welded place is a few so as to minify welding deformation of the bottom steel plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite floor slab made of steel plate and concrete, which is used for road bridge slabs and the like.

[0002]

2. Description of the Related Art In a composite floor slab in which concrete is cast on a steel plate, it is necessary to prevent the steel plate and the concrete from being displaced in order to integrate the steel plate and the concrete. Conventionally, the following three methods are known as this method.

(1) FIG. 6 is a perspective view showing a conventional example of a synthetic floor slab using a stud dowel as a shift preventing member. Figure 6
As shown in, the conventional synthetic floor slab is a steel plate (hereinafter,
It is composed of a plurality of stud dowels 7 arranged by welding on a "bottom steel plate" 1 and concrete 5 which is placed by embedding the stud dowels 7. In this way, the stud dowel 7 used as the shift preventing member enhances the adhesion strength between the bottom steel plate 1 and the concrete 5 (hereinafter referred to as "prior art 1").

(2) FIG. 7 is a perspective view showing a conventional example of a synthetic floor slab in which a shaped steel is used as a shift preventing member. As shown in FIG. 7, this conventional composite floor slab includes shaped steels (L-shaped steel 9) arranged on a bottom steel plate 1 in parallel with each other, and reinforcing bars 8 assembled orthogonally to the L-shaped steel 9. And L-shaped steel 9 and rebar 8 are embedded and concrete 5 is poured. The bottom steel plate 1 and the L-shaped steel 9 are fixed by welding. In this way, the L-shaped steel 9 used as the shift prevention member
The adhesion strength between the bottom steel plate 1 and the concrete 5 is increased (hereinafter referred to as "prior art 2").

(3) FIG. 8 is a perspective view showing a conventional example of a synthetic floor slab in which a grid-like rib is used as a shift preventing member. As shown in FIG. 8, this conventional synthetic floor slab has a grid-shaped rib composed of horizontal ribs 4 and vertical ribs 3 arranged in a grid on a bottom steel plate 1.
It is composed of 10 and concrete 5 which is cast by embedding the grid ribs 10. The horizontal ribs 4 and the vertical ribs 3 are made of flat shaped steel and fixed to the bottom steel plate 1 by welding. In this way, the grid-shaped ribs 10 used as the shift preventing members increase the rigidity of the bottom steel plate 1 and the adhesion strength between the bottom steel plate 1 and the concrete 5 (hereinafter, referred to as "prior art 3"). .

[0006]

However, each of the prior arts 1 to 3 has the following problems.

(1) Problems of Prior Art 1: In order to integrate the bottom steel plate 1 and the concrete 5, it is necessary to hit many stud dowels 7 as shown in FIG. There is. For example, in the case of a synthetic floor slab having a thickness of 150 to 200 mm and the bottom steel plate 1 having a plate thickness of about 6 to 12 mm,
The stud dowel 7 having a diameter of 13 mm and a length of 130 mm is conventionally required to have an interval of about 100 × 100 mm. Further, since the rigidity of the bottom steel plate 1 cannot be increased even if the stud dowels 7 are provided, it is necessary to separately support the rigidity to prevent the bottom steel plate from being caught during concrete pouring.

(2) Problems of Prior Art 2: In the composite floor slab shown in FIG. 7, the L-shaped steel 9 is effective for increasing the rigidity of the bottom steel plate 1. However, the bottom steel plate 1 has an L-shaped steel 9
Since the fillets are continuously welded, the bottom steel plate 1 is likely to undergo welding deformation. Therefore, it is necessary to correct the deformed bottom steel plate 1 or increase the plate thickness of the bottom steel plate 1 so as to reduce welding deformation.

(3) Problems with Prior Art 3: Prior art 2 shown in FIG. 7 has a unidirectional shift prevention function,
Prior art 3 shown in FIG. 8 is an example of a synthetic floor slab in which the horizontal ribs 4 and the vertical ribs 3 are arranged in a quadrangular lattice shape so as to have a shift preventing function in two directions. Such a grid rib 10,
Although it is effective in increasing the rigidity of the bottom steel plate 1 and integrating with the concrete 5, in addition to the problem that welding deformation is more likely to occur than in the prior art 2, the welding work at the intersection of the horizontal rib 4 and the vertical rib 3 is also performed. Is complicated and the workability is poor.

Further, when the prior art 3 is applied to a road bridge deck, a tensile force is repeatedly applied to the bottom steel plate 1 by the load of the traffic vehicle, so that if the number of welded parts with the bottom steel plate 1 increases on the tension side, the steel material There is also a problem that the fatigue strength of is extremely reduced.

Therefore, an object of the present invention is to solve the above-mentioned problems, to ensure the reliable integration of a steel plate and concrete, to eliminate the need for steel plate rigidity reinforcement, and to improve workability during concrete pouring. It is to provide a synthetic floor slab that can.

[0012]

[Means for Solving the Problems] We have conducted extensive studies to solve the above problems. As a result, they have found that the above-mentioned problems can be solved by changing the shape of the stud dowel and the welding method of the grid ribs.

The present invention has been made on the basis of the above-mentioned findings, and a steel plate, a slip prevention member disposed on the steel plate, and the slip prevention member embedded in the steel plate are placed. In the composite floor slab made of concrete, the shift preventing member is arranged at predetermined intervals on the steel plate, has a plurality of slits, and has a plurality of slit gibber and slits of the slit gibber. By a plurality of shaped steels fitted, consisting of grid-shaped ribs arranged in a grid on the steel plate, the steel plate and the dowel with slit, and the dowel with slit and the shaped steel are fixed by welding. It is characterized in that

[0014]

The ribs forming the grid-like rib intersect at the slit-provided dowel, and the grid-like rib and the bottom steel plate are connected via the slit-provided dowel at the intersection. The shearing force generated at the interface between the concrete and the bottom steel plate is transmitted to the grid-shaped ribs, and is further transmitted to the bottom steel plate through the dowel with slit.

The bottom steel plate is reinforced with grid-like ribs, and the rigidity increases in two or arbitrary directions.

In order to minimize the number of welded portions with the bottom steel plate, only the dowel with slit is welded to the bottom steel plate. Since there are few welding points, there is little welding deformation of the bottom steel plate.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1] FIGS. 1 to 5 are drawings showing Embodiment 1 of a synthetic floor slab of the present invention. FIG. 1 is a perspective view showing a state before placing concrete, and FIG. 2 is concrete. 1 is a transverse cross-sectional view in the direction orthogonal to the member axis of FIG. 1, and FIG. 3 and FIG. 4 are perspective views showing a method of joining a pipe pipe with slits and ribs.

As shown in FIG. 3 and FIG. 4, in this embodiment, a slitted pipe dowel (hereinafter referred to as "pipe dowel") 2 in which four slits 11 are provided in a round steel pipe is used as the slitted dowel. Each of the slits 11 is provided in a predetermined length in consideration of the rib height from the upper end of the pipe dowel 2 and in parallel with the axis of the round steel pipe. The pipe dowels 2 are arranged on the bottom steel plate 1 at predetermined intervals with the slits 11 being perpendicular to the bottom steel plate 1, as shown in FIG.
Both are fixed by welding. 6b is a stud weld. The welding method may be either fillet welding or stud welding.

The lateral ribs 4 made of shaped steel (flat steel) are attached in the same direction as the direction perpendicular to the member axis (the direction indicated by the arrow in FIG. 1). The ends of the lateral ribs 4 are fitted in the slits 11 of the pipe dowel 2 as shown in FIG. 3, and the ends of the lateral ribs 4 and the pipe dowels 2 are fixed by fillet welding. 6a is a fillet weld. In addition,
L-shaped cross-section steel may be used as the lateral ribs.

As shown in FIG. 4, the vertical ribs 3 made of shaped steel {T-shaped cross-section steel (hereinafter referred to as "CT-shaped steel (cut T-shaped steel)")} are provided in the slit 11 of the pipe dowel 2 in the lateral direction. It is fitted orthogonally to the rib 4. The vertical ribs 3 and the pipe dowels 2 are fixed to each other by fillet welding. As the vertical rib, flat steel, L-shaped steel, perforated steel (not shown), or the like may be used. The horizontal ribs 4 and the vertical ribs 3 are not welded to the bottom steel plate 1. The horizontal ribs 4 and the vertical ribs 3 arranged in this way form a grid rib 10 arranged in a quadrangle, as shown in FIG.

On the bottom steel plate 1, a pipe dowel 2 as described above is provided.
If a shift prevention member consisting of the grid rib 10 is provided,
A predetermined frame is placed and concrete 5 is poured. As a result, a synthetic floor slab as shown in FIG. 2 is manufactured. If the height of the concrete is the same as the height of the ribs, the grid-shaped ribs act as a frame and it is not necessary to provide a frame.

[Embodiment 2] FIG. 5 is a perspective view showing a second embodiment of the present invention before pouring concrete. As shown in FIG. 5, in the present embodiment, a pipe dowel 2 having six slits in a round steel pipe is used as the dowel with slits, and a rib 8 made of a shaped steel (flat steel) is used. Rib 8 in the slit of 2
This is different from the first embodiment in that the grid-shaped ribs 10 having a zigzag grid shape are formed by fitting the ridges and arranging them so as to intersect each other in a triangle.

In the present invention, by disposing the pipe dowel at an arbitrary position, the lattice ribs are arranged in a triangular shape,
It is possible to freely set a rectangle, hexagon, etc.

[0025]

As explained above, according to the present invention, the following industrially useful effects are brought about.

With respect to the shearing force generated between the bottom steel plate and the concrete, the pipe dowels and ribs can be arbitrarily arranged, and an excellent floor slab structure that is synthetically integrated in two directions or in any direction can be provided.

Since the bottom steel plate is reinforced by the grid ribs, supporting work for the purpose of reinforcing the bottom steel plate is unnecessary. Also, if the height of the concrete is made the same as the height of the ribs, the grid-shaped ribs act as a formwork, and it is not necessary to provide a predetermined formwork for concrete placement, and the workability of concrete placement is improved. Is improved.

Since there are few welding points with the bottom steel plate, welding deformation of the bottom steel plate is small. In addition, the residual strain after welding is small, and it is possible to suppress the decrease in fatigue strength of the steel plate on the tensile side.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention before pouring concrete.

FIG. 2 is a transverse cross-sectional view in the direction perpendicular to the member axis of FIG. 1 in which concrete is poured.

FIG. 3 is a perspective view showing a method of joining a pipe dowel with a slit and a rib.

FIG. 4 is a perspective view showing a method of joining a pipe dowel with a slit and a rib.

FIG. 5 is a perspective view showing a second embodiment of the present invention before pouring concrete.

FIG. 6 is a perspective view showing a conventional example of a synthetic floor slab using a stud dowel as a shift preventing member.

FIG. 7 is a perspective view showing a conventional example of a synthetic floor slab using shaped steel as a shift preventing member.

FIG. 8 is a perspective view showing a conventional example of a synthetic floor slab in which lattice-shaped ribs are used as shift preventing members.

[Explanation of symbols]

 1 Bottom steel plate 2 Pipe dowel with slit 3 Vertical rib 4 Horizontal rib 5 Concrete 6a Fillet weld 6b Stud weld 7 Stud dowel 8 Rib 9 L-shaped steel 10 Lattice rib 11 Slit 11

Claims (1)

[Claims] 1. A composite floor slab comprising a steel plate, a slip prevention member disposed on the steel plate, and concrete cast by embedding the slip prevention member on the steel plate, wherein the slip prevention member is , A plurality of slits having a plurality of slits arranged at predetermined intervals on the steel plate, and a plurality of shaped steels fitted in the slits of the slitting gibber, thereby forming a grid pattern on the steel plate A composite floor slab, wherein the steel plate and the dowel with slit, and the dowel with slit and the shaped steel are fixed by welding.