JPH0215706B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a precast concrete slab equipped with 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.

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, synthetic external walls, etc. that have the necessary strength as a 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.

However, Omnia bars and Kaiser bars both have one upper chord member a and two lower chord members b made of reinforcing bars.
The diagonal members C were connected by reinforcing bars bent in an approximately inverted V shape or zigzag shape, and were joined using welding methods such as spot welding and flashback welding, and were extremely expensive. This is the key to adopting the Omnia version construction method.

In view of this current situation, we provide a precast concrete slab with a three-dimensional truss that has the same advantages as the omnia version without using omnia reinforcement or kaiser reinforcement. and a pair of linear plate portions parallel to the linear plate portion located on both sides thereof, a number of inclined plate portions are provided parallel to each other and located obliquely to these linear plate portions. The provided expanded metal is bent into a substantially inverted V-shape from the straight plate part in the center, and this expanded metal and a similar expanded metal with the inclined plate part in the opposite direction are overlapped and integrated. A certain feature of a three-dimensional truss is that its lower chord is located in the middle of the precast concrete slab in the thickness direction, and the upper chord is buried so that it protrudes from the plane.

Embodiments of the present invention will be described below with reference to 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. 6A, one strip-shaped iron plate 1 is formed with intermittent slits 4 in a substantially V-shape, with straight plate parts 2, 3, etc. left in the center and both sides.
In order to accommodate the A cross-sectional abbreviation U with a length similar to that of 4
A letter-shaped rib 6 is formed.

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. 4, the ribs 5, 5' of the central linear plate parts 2, 2' and the ribs 5, 5' of the linear plate parts 3, 3' on both sides fit together, respectively. and,
Both 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 in terms of strength, and the three-dimensional truss A is manufactured. In FIG. 4, reference numerals 6' are ribs having a substantially U-shaped cross section formed on the inclined plate portions 7', which bulge in a direction opposite to the direction in which the ribs 6 bulge.

Therefore, the inclined plate parts 7, 7' of the expanded metals 8, 8' stacked on the inside and outside become diagonal members c... which are continuous in a zigzag shape when viewed from the side, and the upper chord member a and the two lower chord members b... It has a double structure with two linear plate parts overlapping each other.

Then, a plurality of three-dimensional trusses A manufactured in this manner 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 version B, and the upper chord members a are located in the middle part of the precast concrete version B. A precast concrete slab B is constructed by being buried in a state protruding from one side of B, and equipped with a three-dimensional truss A. 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.

The present invention has the above-mentioned configuration and is economical because it uses a three-dimensional truss manufactured using two pieces of expanded metal instead of the expensive Omnia bars and Kaiser bars. The lower chord material has a structure in which two straight plate parts of both expanded metals overlap, so even if thin and lightweight iron plates are used, sufficient strength can be ensured.
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 could be realized at a low cost.

[Brief explanation of drawings]

Figures 1 and 2 show conventional examples; Figure 1 is a perspective view of the Omnia muscle, Figure 2 is a perspective view of the Kaiser muscle, and Figures 3 to 6 A, B, and C are examples of the present invention. An example is shown, FIG. 3 is a perspective view of the three-dimensional truss, and FIG.
The figure is a sectional view of the space truss, FIG. 5 is a sectional view of a precast concrete plate equipped with the space truss, and FIGS. 6A, 6B, and 6 are process diagrams of the manufacturing method. 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. A three-dimensional truss made by overlapping and integrating metal with the lower chord located in the middle in the thickness direction of the precast concrete slab and the upper chord protruding from one side. Precast concrete version.