JPH10292541A - Precast concrete panel for supporting floor slab and construction method of floor foundation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precast concrete panel useful for achieving the omission of small steel beams and also stiffening members without creating any shortage of strength against the lateral buckling of a large steel beam. SOLUTION: A precast concrete panel 2 is erected between mutually adjacent large beams 1 functioning as the foundation of a floor slab of a building and has both the functions of support and formwork. In this case, its both side portions respectively have a suspending wall 3 covering the side surface of the large steel beam 1, and ribs 4 connecting diagonally the large steel beam 1 to the precast concrete panel 2 are coupled to the suspending walls 3 at certain intervals in the longitudinal direction of the large steel beam 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast concrete plate for supporting a floor slab on a steel girder in a building or the like in which a steel girder is used as a girder which is a basic structural material of a building. Floor construction method.

[0002]

2. Description of the Related Art Conventionally, in order to construct a floor slab on a steel girder, a precast concrete plate or a deck plate is used to simplify installation of a floor slab formwork.
That is, as shown in FIG. 1, a steel beam 21 is bridged between adjacent steel beams 20 and a precast concrete plate 22, for example, is placed thereon. The floor slab is constructed by casting. Furthermore, since a large load may be applied to the steel girders 20 in the event of a large earthquake or the like, the steel girders may be plasticized.In particular, in order to prevent lateral buckling, between the steel girders 20 and the steel girders 21,
The stiffeners 24 are arranged in a toe shape to prevent horizontal movement of the lower flange of the steel girder.

[0003] Therefore, since a steel beam and a stiffener are required between the steel beam and the precast concrete plate, the number of steps required for steel frame processing and installation is increased. In addition, in steel structures, it is essential to coat the surface of steel with refractory materials such as rock wool in order to maintain sufficient strength in the event of a fire. is there.

On the other hand, Japanese Utility Model Laid-Open Publication No. 2-68008 discloses a structure in which steel beams are omitted.
Diagonal members for preventing lateral buckling are still required, and there is a possibility that sufficient strength against lateral buckling cannot be ensured. That is, the bolts are fastened between the diagonal members and the precast concrete plate, but it is difficult to bury the insert hardware accurately in the slab. Considering the nature, it is a long hole. This excessive bolt hole causes a decrease in the shear strength, and even if such considerations are taken, it is expected that it will be difficult to construct the floor slab and the steel beam with the accuracy that can be constructed with bolts.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention
Along with providing a precast concrete plate that helps to achieve omission of steel beams and stiffeners without causing insufficient strength against lateral buckling of steel beams,
An object of the present invention is to propose an advantageous construction method of a floor foundation using the precast concrete plate.

[0006]

SUMMARY OF THE INVENTION The present invention is provided between adjacent steel girders which form the basis of a building floor slab,
A precast concrete plate having both the function of supporting a floor slab and the function of a formwork, and both sides of the precast concrete plate have hanging walls covering the side surfaces of the steel girders. A precast concrete plate for supporting a floor slab, characterized in that ribs which are connected diagonally are provided at intervals in the longitudinal direction of the steel beam.

Here, the rib defines a space filled with mortar between the precast concrete plate and the side surface of the steel beam when the precast concrete plate is laid between adjacent steel beams.
The channel shape advantageously fits.

According to the present invention, when a floor slab is constructed on a steel girder of a building, the precast concrete plate is erected between adjacent steel girder beams, and a side wall of the steel girder is covered with a suspension wall. A method of constructing a floor slab characterized by filling a space defined by a rib and a steel girder obliquely connecting between a steel girder and a precast concrete plate with mortar. Above all,
It is preferable that the space defined by the rib and the steel girder be filled with mortar from the lower end of the steel girder to at least a height of 1/6 or more of the steel girder.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows a precast concrete plate (hereinafter, referred to as a PC plate) 2 installed between adjacent steel girders 1 made of I-beam. PC board 2
When erected on both sides between adjacent steel girders 1,
As shown in FIG. 3, a suspension wall 3 is provided along the side surface of the steel girder 1 to cover the same. Here, after the PC board 2 is erected, the side surface of the steel beam 1 is not exposed, so that it is not necessary to apply the fireproof coating to this side surface.

[0010] Further, as shown in FIG.
A plurality of ribs 4 are provided at a distance in the longitudinal direction of the steel girder 1 so as to obliquely connect the lower surfaces of the steel girder 1 and the precast concrete plate 2.

As shown in FIGS. 4 and 5, the ribs 4 are provided when the PC board 2 is laid between adjacent steel girders 1.
Since the channel shape is open to the side surface of the steel beam 1, a triangular prism-shaped space 5 is formed between the side surface of the steel beam 1 and the rib 4. On the other hand, a mortar introduction hole 6 is provided on the upper surface of the rib 4, and the mortar 7 is filled into the space 5 from the mortar introduction hole 6, whereby the rib 4 is firmly connected to the steel beam 1 and a stiffener for the rib 4 is provided. As a result, a structure that effectively suppresses lateral buckling of the steel girder 1 is obtained.

Next, a method of constructing a floor slab using the PC board 2 will be described with reference to FIG. First, the figure
As shown in (a), a PC board 2 is erected between adjacent steel girders 1 installed at predetermined intervals, as shown in FIG. Thereafter, as shown in FIG. 1C, the mortar 7 is filled into the space 5 between the steel girder 1 and the rib 4 through the introduction hole 6 of the PC board 2.

Here, it is preferable that the mortar 7 is filled from the lower end of the steel girder 1 to at least 1/6 or more of the girder structure and to a height at which the stud bolt can sufficiently exert the strength and the fog can be removed. This is because the lateral buckling of a beam having a short H-shaped section is determined by out-of-plane warpage of the 1/6 section on the compression side. In addition, it is preferable to install a stud bolt 8 on the lower flange of the steel girder 1 to be filled with mortar as shown in FIG.

After filling the mortar 7 between the steel girder 1 and the rib 4, as shown in FIG. 3D, the PC board 2 is used as a mold and concrete is cast on it.
Construction of the floor slab 9 is completed. Here, as shown in FIGS. 3 and 4, a stud bolt is
It is preferable to install concrete at 10 and to cast concrete.

Lastly, it is necessary to provide a fire-resistant coating on the exposed surface of the steel material. The steel girder 1 which is the only steel material in the above configuration is covered with the suspension wall 3 of the PC plate 2 on the side surface. Further, since the upper surface is covered with the floor slab 9, only the remaining lower surface needs to be provided with the fireproof coating 11.

[0016]

By using the PC board of the present invention for the construction of a floor foundation, the omission of steel beams and stiffeners, which has been indispensable in the past, is realized, and at the same time, the side surfaces of the steel beam are left. Since it is covered with the suspension wall, the man-hour required for steel frame processing and installation, and furthermore, the man-hour for fireproof coating can be significantly reduced. Moreover, even if the steel beam and the stiffener are omitted, the strength of the large beam against lateral buckling is maintained at a necessary and sufficient level.

[Brief description of the drawings]

FIG. 1 is a view showing a basic structure of a conventional floor slab.

FIG. 2 is a view showing a state where a precast concrete plate is erected between steel girders.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is a sectional view taken along line CC of FIG. 2;

FIG. 6 is a diagram showing a procedure for constructing a floor slab.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel girder 2 Precast concrete board 3 Suspended wall 4 Rib 5 Space 6 Introducing hole 7 Mortar 8 Stud bolt 9 Floor slab 10 Stud bolt 11 Fireproof coating

Claims (4)

[Claims] 1. A precast concrete plate which is installed between adjacent steel girders as a foundation of a floor slab of a building and has a function of supporting a floor slab and a formwork. A floor slab having a suspension wall that covers a side surface of a girder, and a rib that diagonally connects between the steel girder and the precast concrete plate is provided on the suspension wall at intervals in a longitudinal direction of the steel girder. Precast concrete board for support. 2. The rib according to claim 1, wherein when the precast concrete plate is laid between adjacent steel girders, the rib defines a space filled with mortar between the ribs and the side of the steel girders. The precast concrete plate for supporting the floor slab according to the above. 3. When a floor slab is constructed on a steel girder of a building, the precast concrete plate according to claim 1 is erected between adjacent steel girder beams and a side wall of the steel girder is suspended by a suspension wall. A method of constructing a floor foundation, characterized in that a mortar is filled in a space defined by a rib and a steel girder that obliquely connects between a steel girder and a precast concrete plate while covering the steel girder. 4. A space defined by a rib and a steel girder,
The method for constructing a floor foundation according to claim 3, wherein the mortar is filled from a lower end of the steel girder to at least a height of 1/6 or more of the steel girder.