JPH0765367B2 - Concrete slab with tension film thin steel plate - Google Patents

Description

The present invention relates to a concrete slab with a tension film thin steel plate.

[Prior Art] Conventionally, as a method of constructing a reinforced concrete slab without using a concrete formwork or a supporting structure that supports the concrete formwork, a plurality of steel frame beams are installed side by side in parallel, and a deck plate is mounted on the steel frame beams. A method is generally known in which a flat iron plate is laid and concrete is laid on the flat iron plate to a constant thickness.

[Problems to be solved by the invention]

However, in such a construction method, when the deck plate is used as the concrete formwork, the deck plate cannot bear the tensile force in the direction of the wave, so that it is necessary to consider the orientation when installing.

On the other hand, when a flat iron plate is used as a concrete formwork, since the flat iron plate has a low rigidity in the out-of-plane direction, it is necessary to reinforce it by attaching reinforcing ribs, etc., which requires extra processing and is extremely uneconomical. Is.

Further, in any case, the concrete above the neutral axis and the steel beam become a composite material, only the bending strength on the compression side becomes large, and the bending strength on the tension side is borne by only the lower end of the steel beam. Therefore, the bending strength of the slab as a whole does not increase as expected.

The present invention has been made to solve the above problems, and is a concrete slab with a tension film thin steel sheet, which is extremely economical and has a very large bending resistance, without using a conventional formwork or supporting structure. It is intended to provide.

[Means for solving problems]

The concrete slab with a tension film thin steel plate according to the present invention is constructed by arranging a plurality of steel beams side by side at regular intervals in the width direction, suspending a membrane steel plate between the steel beams in the central portion thereof, and the both ends of the steel beam. Attached by welding to the lower flange, a plurality of tension members are attached between the steel frame beams, and, depending on the amount of suspension of the membrane steel plate on the membrane steel plate, the thickest in the central portion of the membrane steel plate, It is constructed by pouring concrete so that it becomes the thinnest in the steel beam portion.

〔Example〕

1 and 2 show an embodiment of a reinforced concrete slab with a tension film thin steel sheet according to the present invention, in which a plurality of steel frame beams 1 made of H-shaped steel are arranged at substantially equal intervals in the width direction. It is installed side by side.

In addition, a membrane steel plate 2 (thin iron plate) between the steel beams 1 and 1
Is attached to the steel beam by this membrane steel plate 2.
The entire lower side between 1 and 1 is covered.

The membrane steel plate 2 is attached by welding the left and right edge portions thereof to the lower flanges 1a, 1a of the steel frame beams 1, 1, respectively, and the central portion thereof is suspended by a certain amount in a convex curved shape.

The thickness and tensile force T of the membrane steel plate 2 are determined according to the suspension amount f of the membrane steel plate 2 so that an optimum design can be performed.

That is, when the suspension amount f of the membrane steel plate 2 is increased, the tensile force T acting on the membrane steel plate 2 is reduced, and therefore the thickness of the membrane steel plate 2 can be reduced, while the suspension amount of the membrane steel plate 2 is reduced. If f is made small, the tensile force T acting on the membrane steel plate 2 becomes large, so it is necessary to make the thickness of the membrane steel plate 2 thick.

Concrete 3 is placed on the upper side of the membrane steel plate 2 according to the amount of suspension of the membrane steel plate 2 so that it is thickest in the central part of the membrane steel plate 2 and thinnest in the steel beam 1 part. The upper flange 1b and the web of each steel beam 1 are completely embedded in the concrete 3 and completely integrated with the concrete 3.

In addition, even if an unexpectedly large tensile force is applied to the membrane steel plate 2 in the event of an earthquake, a lightweight chevron-shaped steel is used between the steel beams 1 and 1 in order to prevent vibrations and sufficiently cope with strength. A plurality of tension members 4 made of channel steel are attached.

Further, if necessary, in the concrete 3, as in the case of the conventional reinforced concrete slab, a plurality of reinforcing reinforcing bars 5, 5
Are arranged in one or two steps.

In this case, the reinforcing reinforcing bar 5 arranged on the lower side is necessary when the cross section is insufficient with only the steel beam 1 against the tensile force on the lower side of the slab due to the bending moment. There is no particular need for proof stress, rather it is more economical to do so and labor is saved in construction.

In such a configuration, with respect to the tensile force at the lower end of the slab due to the bending force having the width direction of the steel beam 1 as an axis, the steel beam 1
Since the lower flange portion 1a and the membrane steel plate 2 are integrated and resist, the tensile strength is remarkably improved.

On the other hand, the membrane steel plate 2 and the tensile member 4 resist the tensile force at the lower end of the slab due to the bending force having the longitudinal direction of the steel beam 1 as an axis. In this case, the reason why the membrane steel plate 2 suspended downwardly in a convex curved shape resists the tensile force is because the curvature of the membrane steel plate 2 is not so large, and the concrete steel plate 3 makes the membrane steel plate 2 linear. This is because the force to try is restricted.

〔The invention's effect〕

The concrete slab with the tension film thin steel plate according to the present invention has the following effects because it has the configuration described above.

A plurality of steel beams are laid side by side at regular intervals in the width direction, a membrane steel plate and a plurality of compression members are attached between the steel beams, the membrane steel plate suspends its central portion, and both ends are the steel beam. Attached to the lower flange by welding, and the concrete becomes the thickest in the central part of the membrane steel plate and the thinnest in the steel beam part depending on the suspension amount of the membrane steel plate. Since it is constructed by driving as described above, there is an effect that it can be easily and economically constructed without using a conventional formwork or supporting structure.

Also, since the central part of the membrane steel plate is attached by suspending a certain amount in the shape of a convex curved surface, it does not only work as a formwork for curing concrete immediately after placing it, but it is integrated with the steel beam after concrete hardening. It has the effect of resisting bending force.

In addition, since it is reinforced by installing multiple tension members between the steel beams, even if an unexpectedly large tensile force acts on the membrane steel plate in the event of an earthquake, etc., it is possible to sufficiently cope with the strength and improve the structural strength. I haven't had any problems.

Further, since the concrete beams are cast, the adjacent steel beams are integrally connected, and the rigidity of the slab is remarkably enhanced, so that vibration of the slab can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 show an embodiment of a concrete slab with a tension film thin steel plate according to the present invention, and FIG. 1 is a vertical sectional view of a concrete slab with a tension film thin steel plate, FIG. 2 is a perspective view showing an installed state of a membrane steel plate. 1 ... Steel beam, 2 ... Membrane steel plate, 3 ... Concrete,
4 ... Tensile member, 5 ... Reinforcing bar.

Claims (1)

[Claims] 1. A plurality of steel beams are installed side by side at regular intervals in the width direction, a membrane steel plate is suspended between the steel beams at the central part, and both ends are welded to the lower flanges of the steel beams to be mounted. , A plurality of tension members are attached between the steel beam, and, depending on the amount of suspension of the membrane steel plate on the membrane steel plate, the thickest in the central portion of the membrane steel plate, the most in the steel beam portion. A concrete slab with a tension film thin steel plate, which is made by placing concrete so as to be thin.