JPH10102654A - Method of manufacturing floor slab PC plate with small beams - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide a method of manufacturing a floor slab PC plate with small beams, which can design a cross-sectional dimension of a steel beam supporting a floor slab to be small. A stud bolt is attached to one flange of a steel beam. The steel beam 1 is suspended and supported between the pair of mounts 3 with the stud bolt 2 side facing downward. Next, the formwork 4 is suspended from the steel beam 1. The main bars 13 for slabs are arranged in the formwork 4. Next, concrete 15 is cast into the formwork 4. And the floor slab P with small beams manufactured as described above
Turn the C-version over and use it between the girders.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floor slab PC with small beams in which steel beams are integrally joined with floor slab concrete.
The present invention relates to a plate manufacturing method.

[0002]

2. Description of the Related Art The construction of a floor slab in a steel structure building is generally performed by the following construction.

That is, as shown in FIG. 7 which is a plan view, a steel beam 51 is suspended between opposing beams 50 of a steel beam 50 arranged in a lattice shape. Both ends in the longitudinal direction are respectively joined to the girders 50 by pin support.

After the steel beams 51 are installed, as shown in FIG. 8, a deck plate 52 is laid between the beams, stud bolts 53 are struck on upper flanges of the steel beams 51, and a reinforcing bar for floor slabs is further provided. After arranging the reinforcements such as 54, concrete 55 is poured and a floor slab is constructed.

[0005]

When a floor slab is constructed as described above, the steel beam 51 is provided with fixed loads such as a steel frame own weight, a deck plate 52, a floor slab concrete 55, and a floor finishing material. Each weight is applied, and is further loaded.

[0006] Generally, the steel beam 5 is so designed that these loads can be received only by the cross section of the steel beam 51.
Although the cross-sectional design of No. 1 is performed, conventionally, it is necessary to select the cross-section of the adopted steel beam 51 that can tolerate the fixed load and the load from the no-load state. There is a problem that the cross-sectional dimension required for the beam 51 is large.

After the poured concrete 55 has hardened, the concrete 55 and the steel beam 51 are integrated with each other, so that the composite beam of the steel beam 51 and the floor slab concrete 55 is not subjected to the load. In some cases, a cross-sectional design is made, but there is a similar problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method of manufacturing a floor slab PC plate with small beams that can design a required cross-sectional dimension of a small steel beam. It is an issue.

[0009]

In order to solve the above-mentioned problems, a method of manufacturing a floor slab PC plate with small beams according to the present invention comprises: Supporting both ends in the longitudinal direction in a downward direction, suspending a formwork for floor slab concrete from the steel beam, and before and after the suspension, reinforcing concrete is provided in the formwork, and then concrete is removed. It is characterized by being cast and manufactured.

[0010] Supporting both ends of the steel beam in the longitudinal direction means supporting the steel beam under the same condition as that at the time of permanent installation or in a state close to that at the time of permanent installation. According to the invention,
Until the steel beams are supported upside down from the installation state of the main building and the concrete poured into the formwork hardens,
It supports the weight of concrete and the weight of concrete, which is a fixed load only in the steel cross-section, but when the concrete hardens and the concrete and steel are integrated, a composite beam is formed, which is the reverse of that at the time of permanent construction. The direction prestress is introduced into the steel beam.

In addition, by introducing the above-mentioned prestress into the steel beam, the prestress in the compression direction is introduced into the concrete itself by the stress transmitted from the steel beam.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. First, a method for manufacturing a floor slab PC plate with small beams will be described.

First, a stud bolt 2 serving as a shear connector is driven into one flange portion of a target steel beam 1 and the stud bolt 2 is attached. Next, as shown in FIG. 1, the steel beam 1 is suspended and supported between the pair of gantry 3 with the stud bolt 2 side facing downward. FIG. 1 shows only some of the stud bolts 2.

Each of the pedestals 3 includes a column 3a made of a shaped steel to be erected and an overhang 3b projecting laterally from the pillar 3a toward the other gantry 3. 3b, a bolt hole for fixing the small beam 1 is formed.

Then, the steel beam 1 is attached to the overhang 3b.
Under the same support conditions as at the time of main construction. That is, both ends in the longitudinal direction of the web portion 1a of the steel beam 1 are bolted to the overhang portion 3b.

Next, the formwork 4 is suspended from the steel beam 1. The bottom plate portion of the formwork 4 is configured by reinforcing a floor finishing panel 5 with a flat deck panel 6. The side portion 7 is installed on the bottom plate portion so as to form a PC plate as shown in FIG. 3 which is a plan view. That is, the manufactured PC plate has a rectangular shape in plan view, but the vicinity of both ends of the steel beam 1 is cut away to form a concave portion 8 when viewed from above. The recess 8 serves as an opening when the steel beam 1 is attached to the girder 9.

As shown in FIG. 2, the hanging member mounting bracket 10 mounted on the upper surface of the bottom plate of the formwork 4 is provided.
The form 4 is suspended from the upper flange 1b of the steel beam 1 by a wire rope 11 whose both ends are connected to each other.

Next, the length of the wire rope 11 is adjusted by a turnbuckle 12 interposed in the middle of the wire rope 11, and the distance between the lower flange 1c of the steel beam 1 and the panel 5 of the formwork 4 is reduced. , So as to be equal to the target floor slab thickness.

Next, the main reinforcement 1 for the slab is placed in the form 4.
Arrange 3 bars. This arrangement may be performed before the form 4 is suspended from the steel beam 1. Next, concrete 15 is cast into the formwork 4. In addition, in order to suppress the shaking of the formwork 4 during concrete casting, it is preferable to provide a pressing member that presses the side of the formwork 4 from the lateral direction.

At this time, until the cast concrete 15 hardens, its own weight and concrete 15
Is applied, and the load is received by the cross section of the steel beam 1
The steel beam 1 is in a state in which a downward vertical load (upward load in the present state) is applied.

When the concrete 15 hardens in this state, the concrete 15 and the steel beam 1 are integrated to form a composite beam, and the load is applied to the steel beam 1. In other words, a vertical prestress is introduced into the steel beam 1 (vertically upward in the case of permanent installation).

In addition, since the prestress is introduced into the steel beam 1, a stress in the compression direction is applied to the concrete 15, and the prestress in the compression direction is also applied to the concrete 15.

Next, the wire rope 11 as a hanging material is removed, and the small beam 1 steel frame is removed from the gantry 3. This means that the floor slab PC plate P with small beams has been manufactured.

Next, the floor slab PC with small beams manufactured as described above is used.
Construction of a floor slab using the plate P will be described. The PC slab P with small beams manufactured as described above is turned over, and the PC slab P is suspended between the girders 9 as shown in FIG. 3, that is, with the floor slab side up. That is, while placing both sides of the PC plate P in the longitudinal direction on the girders 9,
The web portion 1a of the steel beam 1 is joined to the web portion 1a of the girder 9. In FIG. 3, the reinforcing bar 13 protruding from the floor slab PC plate P is omitted, and actually, as shown in FIGS. 4 and 5, the reinforcing bar 13 protrudes.

As shown in FIG. 5 and FIG. 6, the joint between the girder 9 and the girder 1 is
Attachment is carried out by joining the bolts or rivets to the bolts. At this time, since the concrete 15 portions at both ends of the steel frame beam 1 in the PC plate P are notched, even if the steel frame beam 1 is integrated with the concrete 15 in advance, the joining is performed in the conventional manner. It can be implemented similarly.

Further, the construction of the floor slab is completed by placing concrete 15 in the slab portion 19 between the attached PC plates P. As a result of the upward pre-stress being applied to the steel beam 1 attached as described above in the state of permanent installation, the stress generated in the beam 1 due to the fixed load or the load after the installation is the same as that of the conventional example. It becomes smaller than the case. Therefore, it is possible to design the cross section of the small beam 1 smaller than before. That is, the sectional size of the steel beam 1 can be reduced, and the amount of steel frame can be reduced.

Also, floor slab concrete 1 of PC version P
Since the compressive force is applied in advance to the five portions, the tensile force generated in the concrete 15 is reduced as compared with the conventional case, and cracks are less likely to occur.

Further, while the floor slab concrete 15 and the steel beam 1 are integrated, only the slab portion between the PC plates P as shown in FIG. On-site casting amount is reduced. For this reason, the construction of the floor slab is simple and quick.
In addition, in cold regions, this leads to an effect that the cost of curing is reduced.

Further, the PC plate P is prepared at the time of manufacture by using the floor surface form 4
Since the upper surface is automatically pressed by its own weight, there is also an effect that the ironing work for floor finishing is reduced.

In the method of manufacturing the PC plate P described above, the form 4 is hung by attaching the end of the wire rope 11 which is a form hanger to the bottom of the form 4. A portion 10 of the material is embedded in concrete 15, but is not limited to this.

For example, the end of the wire rope 11 may be connected to the upper part of the side plate 7 of the formwork 4 so that a part of the hanging material is not buried in the cast concrete 15.
Further, the hanging member is directly in contact with the upper flange portion 1b of the steel beam 1; however, a metal fitting for fixing the wire rope 11 to the flange portion 1b is provided between the flange portion 1b and the hanging member. Is also good.

Further, in the above description, an example in which the steel beam 1 is attached to the gantry 3 under the same conditions as when the main beam is installed, but the flange of the steel beam 1 is attached to the overhang 3b. Both ends of the steel beam 1 in the longitudinal direction may be supported by other means such as supporting the portion 1b by hooking.

[0033]

As described above, the floor is constructed by using the floor slab PC plate with small beams manufactured by the method of manufacturing the floor slab PC plate with small beams of the present invention.
The load that can be supported by a steel beam with the same cross section is increased more than before. Therefore, the cross section of the steel beam can be designed to be smaller than before, and there is an effect that the amount of steel frame used for the building can be reduced accordingly.

Further, the floor slab PC with small beams manufactured as described above is used.
By using the slab, the pre-stress in the compression direction is introduced into the floor slab concrete part at the time of main construction, the tensile force applied to the concrete is reduced than before, and the floor concrete is less likely to crack There is also an effect.

[Brief description of the drawings]

FIG. 1 shows a floor slab P with small beams according to an embodiment of the present invention.
It is a side view for explaining the manufacturing method of C version.

FIG. 2 is a diagram for explaining suspension of a formwork from a steel beam according to the embodiment of the present invention.

FIG. 3 is a plan view showing a state in which a floor slab PC plate with small beams is erected between girders.

FIG. 4 is a side view showing a state between laid PC plates.

FIG. 5 is a partially enlarged view of a floor slab PC version with small beams supported by large beams.

FIG. 6 is a side view showing a joint between a large beam and a small beam.

FIG. 7 is a diagram showing a relationship between a large beam and a small beam.

FIG. 8 is a diagram for explaining a conventional floor slab construction.

[Explanation of symbols]

 PPC version 1 steel beam 2 stud bolt 3 gantry 4 formwork 5 floor finishing panel 6 flat deck panel 9 girder 11 wire rope 13 rebar

Claims (1)

[Claims] 1. A steel beam to which a shear connector is attached is supported at both longitudinal ends thereof with the shear connector side facing downward, and a formwork for floor slab concrete is suspended from the steel beam, A method for producing a floor slab PC plate with small beams, wherein concrete is cast after producing reinforcement in a formwork before and after the suspension.