JPH0642180A - Prestressed concrete double t-type floor slab with tension chord member - Google Patents

Abstract

PURPOSE:To make a slab possible to be largely spanned in keeping its length constant intact by forming the slab into a double T-type sectional form while curving it upward, installing a tension chord member in space between fulcrums of the slab, and setting up a bundle member between the slab and the tension chord member. CONSTITUTION:A roof slab 1 is curved upward at the specified curvature, and made into a double T-type sectional form where a slab 1a and plural beams 1b parallelly installed are made up as one body. Prestressed concrete is taken into the roof slab 1 at need for reinforcement, so precast steel is inserted into concrete at a lower end of the beam 1b. A tension chord member 2 is installed in space between two fulcrums in the short side direction of the roof slab 1 at the lower side of this slab 1, and a central part of the tension chord member 2 is supported on the slab 1 by a bundle member 3. Therefore axial tension is mainly acting on the roof slab 1, a structurally disadvantageous bending stress is sharply reduced and, what is more, only tensile force acts on the tension chord member 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prestressed concrete double T type slab with a string material constructed as a roof slab or a floor slab of a building.

[0002]

2. Description of the Related Art Conventionally, in order to enable a floor slab to have a large span, the floor slab is a double T-shaped slab (joist slab) and PC is placed in the concrete of the floor slab. A method of introducing prestress by inserting a steel material has already been implemented by on-site construction or computerization.

[0003]

However, even with this type of floor slab, there is a limit to the expansion of the span, and the weight of the floor slab must be increased because the slab must be increased in order to achieve a large span. However, there was a problem that the slabs became bigger and there were design problems.

The present invention has been made in order to solve the above problems, and provides a prestressed concrete double T-type slab with a tension string material, which makes it possible to increase the span of the slab while keeping the slab's fault constant. The purpose is to

[0005]

A prestressed concrete double T-shaped slab with a stringed material according to the present invention comprises a slab having a double T-shaped cross section and is curved upward, and a stringed material is installed between fulcrums of the slab. Moreover, a bundle member is installed between the slab and the stringed string member.

[0006]

1 to 3 show an embodiment of a prestressed concrete double T type slab with a stringed string material according to the present invention, FIG. 1 is a vertical sectional view of a roof slab, and FIG. 2 is a detailed view of part A in FIG. 3 is a detailed view of a portion B in FIG.

In the drawing, reference numeral 1 is a roof slab, 2 is a tension string material installed between fulcrums of the roof slab 1, 3 is a tension string material 2
A bundle material that supports an intermediate portion of the above, and reference numeral 4 is a roofing material made of a metal plate or the like.

The roof slab 1 has a double T-shaped cross-section which is curved upward with a constant curvature and which is integrally formed with a plurality of beams 1b installed in parallel with the slab 1a (also called a joist slab). Say).

If necessary, a PC steel material (not shown) is inserted into the concrete at the lower end of the beam 1b in order to introduce prestress to the roof slab 1 to reinforce it.

The roof slab 1 is made of cast-in-place reinforced concrete or precast reinforced concrete, and in any case, it has a non-reinforced structure by using reinforcing fibers such as carbon fibers instead of reinforcing reinforcing bars. Sometimes.

The string members 2 are installed below the roof slab 1 between fulcrums in the short side direction of the roof slab 1, and both ends thereof are rotatably connected to anchor members 5 embedded in the concrete of the floor slab 1. ing.

Further, the stringed chords 2 are erected at predetermined intervals depending on the size of the slab, and the central portion of each stringed chord 2 is supported by the floor slab 1 by the bundle 3. It should be noted that PC steel material or the like is used for the string material 2 and steel frame material or the like is used for the bundle material 3.

In such a structure, the roof slab 1 has a double T-shaped cross section, is curved upward with a constant curvature, and is reinforced by the stringed string member 2 so as to maintain the curved state. As a result, the axial force (compression) acts mainly on the roof slab 1, and the structurally disadvantageous bending stress is significantly reduced. Further, only the tensile force acts on the tension string material 2. Therefore, it becomes possible to increase the span of the roof slab while keeping the fault of the roof slab 1 constant.

[0014]

The present invention is configured as described above, the slab is configured to have a double T-shaped cross section, is curved upward with a constant curvature, and is reinforced so as to maintain the curved state by the stringed string material. As a result, the axial force (compression) acts mainly on the slab, and the structurally disadvantageous bending stress is significantly reduced. Further, only tensile force acts on the stringed material. Therefore, it is possible to increase the span of the slab while keeping the fault of the slab constant.

It is also possible to improve the workability by using a reinforcing fiber such as carbon fiber in place of the reinforcing reinforcing bar to form an unreinforced structure.

Further, since it is not necessary to increase the size of the slab, the design problem can be solved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of a prestressed concrete double T type floor slab with a tension chord material according to the present invention.

FIG. 2 is an enlarged detailed view of a portion A in FIG.

3 is an enlarged detailed view of a B part in FIG. 1. FIG.

[Explanation of symbols]

1 ... Roof slab, 2 ... Stranded string material, 3 ... Bundle material, 4 ... Roofing material.

Claims (1)

[Claims] 1. A slab having a double T-shaped cross-section, curved upward, erected a string material between fulcrums of the slab, and installing a bundle between the slab and the string material. A prestressed concrete double T-shaped slab with a characteristic string material.