JPH0335458B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a precast concrete material having a three-dimensional truss, which is used to form a composite slab, a composite exterior wall, etc. by strongly bonding and integrating with cast-in-place concrete. It concerns concrete slabs.

[Conventional technology]

In recent years, in construction work, with the aim of saving labor and shortening the construction period, the so-called Omnia version construction method is used, in which Omnia version is used as a formwork and concrete is poured on-site to construct composite slabs, composite external walls, etc. that have the strength required for the structure. is being carried out.

This Omnia version is the first three-dimensional truss that is buried on one side of the precast concrete version in order to ensure the cross-sectional performance of the version in a semi-finished state and to connect it with cast-in-place concrete when constructing composite slabs. It uses the Omnia muscle shown in the figure and the Kaiser muscle shown in Figure 2, and has excellent strength characteristics.

[Problem to be solved by the invention]

Omnia bars and Kaiser bars are both composed of reinforcing bars made of one upper chord member a and two lower chord members b, which are connected by reinforcing bars bent in an approximately inverted V shape or zigzag shape to form diagonal member c. , spot welding, flashback welding, and other welding methods, which are extremely expensive, and this is the bottleneck in adopting the Omnia version method.

In view of the current situation, the present invention provides a precast concrete slab equipped with a three-dimensional truss that has the same advantages as the omnia slab without using omnia reinforcement or Kaiser reinforcement.

[Means to solve the problem]

The technical means taken by the present invention to achieve the above object are as follows. That is, in the precast concrete slab equipped with the three-dimensional truss according to the present invention, there is a space between a linear plate part located in the center and a pair of linear plate parts parallel to the linear plate part located on both sides of the linear plate part. , an expanded metal having a large number of inclined plate parts that are parallel to each other and located diagonally with respect to these linear plate parts is bent into a substantially inverted V-shape from the central linear plate part, and this expanded metal A three-dimensional truss made by overlapping and integrating a similar expanded metal with the inclined direction of the inclined plate part reversed, and crimping the central linear plate part of both expanded metals to a deformed reinforcing bar placed inside the expanded metal. , the lower chord of which is located in the middle of the precast concrete slab in the thickness direction,
The top chord is embedded with the upper chord protruding from one side.

[Effect]

According to the above configuration, the top chord of the three-dimensional truss, which protrudes from the concrete surface and requires strength, is a composite structure of the overlapping portion of the linear plates of two expanded metal plates and deformed reinforcing bars. Because of this, great strength can be obtained.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In the figure, A is a three-dimensional truss, and B is a precast concrete plate equipped with a three-dimensional truss.

The space truss A mentioned above is manufactured as follows. That is, as shown in FIG.
... are inserted, and in order to increase the rigidity, ribs having a substantially U-shaped cross section are inserted over the entire length of the linear plate portions 2, 3... 5 are formed, and ribs 6 having a substantially U-shaped cross section and having a length comparable to the length of the slits 4 are also formed on the plate portion located between the slits 4.

Next, as shown in FIG. 6B, the strip iron plate 1 is stretched in the width direction, and a linear plate part 2 located in the center and a pair of parallel linear plate parts 3 located on both sides...
and parallel to each other and linear plate portions 2, 3...
A large number of short inclined plate portions 7 located obliquely to the
An expanded metal 8 provided with... is manufactured, and this is bent into a substantially inverted V-shape from the straight plate portion 2 at the center, as shown in FIG. 6C.

On the other hand, an expanded metal 8' in which the direction of inclination of the inclined plate part 7' is reversed is manufactured by the same method as the expanded metal 8 described above from a band-shaped iron plate having slits in opposite directions.

Then, connect both expanded metals 8 and 8' to the third
As shown in FIG. and,
The two expanded metals 8, 8' are stacked so that the upper ends and lower ends of the inclined plate parts 7, 7' are aligned with each other, respectively, and the straight plate parts 2, 2', 3 are formed.
..., 3'... are integrated by spot welding at appropriate intervals for strength, and both expanded metal parts 8,
The deformed reinforcing bars 10 are arranged inside the central straight plate parts 2, 2' at 8', and the deformed reinforcing bars 10 are placed by pressing both the straight plate parts 2, 2' from the outside.
A space truss A is manufactured in which the upper chord member a has a composite structure of both linear plate portions 2, 2' and the deformed reinforcing bar 10. 6' in FIGS. 3 and 4 are ribs with a substantially U-shaped cross section formed on the inclined plate portion 7'.
The ribs 6 are bulged in a direction opposite to the direction in which the ribs 6 are bulged.

Therefore, the inclined plate parts 7, 7' of the expanded metals 8, 8' stacked on the inside and outside become diagonal members c that are continuous in a zigzag shape when viewed from the side, and the upper chord member a is formed by overlapping two straight plate parts. It becomes a composite structure of the joined part and the deformed reinforcing bar 10, and the two lower chord members b... are 2
It has a double structure of overlapping linear plates.

As shown in Fig. 5, a plurality of three-dimensional truss A manufactured in this way are arranged parallel to each other, and the lower chord members b are located at the middle part in the thickness direction of the precast concrete slab B, and the upper chord members A is buried in a state protruding from one side of a precast concrete version B, and a precast concrete version B including a three-dimensional truss A is constructed. In the figure, 9 is the meshwork muscle.

In addition, in the above embodiment, the expanded metal 8,
8' were stacked so that the upper ends and lower ends of the inclined plate parts 7 and 7' were aligned with each other, but by shifting the positions of the upper ends and the lower ends of the inclined plate parts 7 and 7', May be overlapped.

〔Effect of the invention〕

The present invention has the above-mentioned configuration, and uses a three-dimensional truss manufactured using two pieces of expanded metal and deformed reinforcing bars instead of expensive Omnia bars and Kaiser bars, so it is economical, and especially suitable for concrete surfaces. The upper chord of the three-dimensional truss, which protrudes from the ground and requires great strength, has a composite structure of the overlapping part of two linear plates of both expanded metals and deformed reinforcing bars, so we used thin and lightweight iron plates. However, sufficient strength can be ensured, and material costs can be reduced. Therefore, a precast concrete slab equipped with a three-dimensional truss that has the same advantages as the Omnia slab can be realized at a low cost.

[Brief explanation of the drawing]

FIGS. 1 and 2 show conventional examples, with FIG. 1 being a perspective view of the muscle of Omnia, and FIG. 2 being a perspective view of the muscle of Kaiser. 3 to 6 A, B, and C show embodiments of the present invention, FIG. 3 is a perspective view of the space truss, FIG. 4 is a sectional view of the space truss, and FIG. 5 is a cross-sectional view of the space truss. The cross-sectional views of the precast concrete slab provided in FIGS. 6A, 6B, and 6C are explanatory diagrams of the expanded metal manufacturing process. 2, 2'... linear plate part, 3, 3'... linear plate part, 7, 7'... inclined plate part, 8, 8'... expanded metal, A... three-dimensional truss, B...... Precast concrete version, a...Top chord member, c...Diagonal member.

Claims (1)

[Claims] 1. Between a linear plate located in the center and a pair of linear plates parallel to the linear plate located on both sides thereof, a line parallel to each other and oblique to these linear plates is provided. An expanded metal with a large number of inclined plate parts located at the central part is bent into a substantially inverted V shape from a straight plate part in the center, and this expanded metal and a similar expanded metal with the inclined direction of the inclined plate parts reversed. The three-dimensional truss is made by overlapping and integrating metal and crimping the center linear plate of both expanded metals to deformed reinforcing bars placed inside, and the lower chord is the middle of the precast concrete slab in the thickness direction. A precast concrete slab with a three-dimensional truss located at the top of the wall with the top chord protruding from one side.