JPH0449615B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a concrete-covered truss and a method of manufacturing a floor slab using a concrete-covered truss.

Conventionally, the following methods for manufacturing concrete beams, concrete slabs, and floor slabs using these slabs using trusses, particularly reinforcing steel trusses, are known. That is, first, we use Omnia reinforcing bars in which the upper and lower chord members are connected by lattice bars, fix the Omnia plate to the bottom of the Omnia reinforcing bars, install a welded wire mesh, and then connect the upper and lower chord members of the Omnia reinforcing bars. This is an omni slab, in which the upper floor and lower floor ceiling are obtained by pouring cast-in-place concrete thicker than the floor. Next, EBS slabs are also known, in which cast-in-place concrete is poured onto a reinforcing steel slab with concrete with the concrete pouring side facing down and thicker than the height of the slab. Furthermore, filli-grain slabs are also known, which use a truss whose top chord is made of V-steel and whose lattice is made of reinforcing steel, and the truss section is placed on the flat upper floor surface and the lower side of that surface using cast-in-place concrete. The lower floor ceiling surface has projections according to the following. Others, such as built slabs, are known. These reinforcing bar trusses act as structural reinforcement for the slab and also serve as support during concrete pouring, but since the conventional construction method using trusses has problems with the strength of the top chord, they must be prepared in advance. Prevention of lateral buckling of the top chord of the truss must be taken into consideration, and solid buckling of the top chord and overall buckling are likely to occur, making it unsuitable for making long-span slabs. Furthermore, with conventional floor slabs using reinforced steel slabs, in order to obtain sufficient strength, it is necessary to pour cast-in-place concrete that is thicker than the height of the slab, and the ceiling side of the lower floor has unevenness, making it difficult to place the concrete under the upper floor. Because the sides are flat, it is not possible to make effective use of the space between the ceiling and floor, and even if there is a recess, the ceiling side is concave, which limits the effective use of wiring and piping. However, the appearance of the ceiling surface was lacking in the first place.

Therefore, the present invention provides a truss with concrete that is characterized in that concrete is fixed to the convex side of the truss having a hollow, and a concrete fixed side of the truss with concrete that is characterized in that concrete is fixed to the convex side of the truss that has a hollow. At the top, the non-concrete fixed side of the truss with concrete is fixed to the slab formwork, reinforcement is placed between the trusses with concrete that are similarly fixed to the slab formwork, and the end of the truss with concrete is fixed to the beam. A method for producing a floor slab using concrete-covered trusses, characterized in that cast-in-place concrete is placed between concrete-covered trusses to the extent that the concrete side of the concrete-covered trusses protrudes from the poured-in-place concrete surface. The present invention aims to eliminate the above-mentioned drawbacks.

The present invention will be explained below with reference to the drawings.
First, a truss with concrete will be explained with reference to FIGS. 1 and 2, which show front views. 1 is a reinforcing bar truss. The reinforcing bar truss 1 has a predetermined bulge similar to a conventional reinforcing bar truss with concrete. For example, the peeling amount is (/200~/
∞) is possible. As a result of the rounding, the central portion becomes convex upward as shown in FIG. Next, concrete 2 is cast and fixed on one side of the reinforcing bar truss 1, but since conventional trusses with concrete, especially reinforcing bar trusses with concrete, are used at construction sites with the concrete pouring side facing down, as shown in Fig. 1. Concrete was placed on the lower side of the truss, that is, on the concave side, and fixed in place while applying a constant pressure from above. However, in this invention, since the truss is used at a construction site with the concrete pouring side facing upward, there is no need to apply pressure from above the reinforcing bar truss during concrete pouring. That is, as shown in FIG. 2, the reinforcing bar truss 1 is turned upside down and set on a production bed (not shown) with the concave side facing upward. Then, concrete 2 is placed on the convex side of the reinforcing bar truss, that is, the lower side in FIG. Reinforcement truss 3 with concrete is obtained. This concrete truss is stocked at predetermined locations.

That is, in the concrete-attached truss of this invention, concrete is fixed to the convex side of the hollowed truss, that is, the reinforcing bar truss 1 of this embodiment. The cross section of the completed reinforcing bar truss with concrete is shown in Fig. 3a, which represents the cross section A-A in Fig. 2, and about half of the reinforcing bar truss part may be exposed from the concrete, but as shown in Fig. 3b, The degree of exposure is even better.

This invention is used with the concrete fixed side facing up, but in that case, the truss reinforcements on the compression side, which have lower strength than tension, are fixed with concrete, so the cross-sectional strength of the slab is improved. Therefore, it is possible to make slabs with longer spans than before, and when manufacturing according to the present invention, there is no need for the process of pressing force from above, which was required when manufacturing conventional slabs with concrete. Next, a method for manufacturing a floor slab using this concrete-attached truss will be explained. The stocked concrete reinforced truss 3 is loaded onto a truck or the like and transported to a construction site, as shown in FIG. The reinforcing bar truss 3 with concrete has the convex side, that is, the concrete placement side, as the upper side as shown in FIG. 5, and then fixes the reinforcing bars 1 on the non-concrete placement side, that is, the reinforcing bar exposed side, to the slab formwork 4. . A spacer 5 is used for fixation. Similarly, slab reinforcement 6 is placed between the reinforcing bars of other concrete-attached reinforcing bars truss fixed to the slab formwork 4. Next, the reinforcing bars at the ends of the concrete-attached reinforcing bar truss are fixed onto the girders 8 via the girder main reinforcements 7, as shown in FIGS. 6 and 7. In this embodiment, the reinforced concrete truss 3 is fixed to the main beam, but it may also be fixed to the small beam. Beam side forms 9 are set on both sides of the girder 8. Next, cast-in-place concrete 10 is placed as shown in FIG. It is sufficient to pour concrete in such an amount that the concrete side of the reinforcing steel truss 3 with concrete protrudes from the cast-in-place concrete surface. This is not necessary because the concrete truss has a cross-sectional strength greater than that of a conventional truss. When the formwork is removed, a floor slab 11 as shown in FIG. 9 is obtained which has a flat ceiling surface on the lower floor and a concave portion on the lower surface of the upper floor. Piping and wiring are installed in the recess, and a floor plate 13 is fixed onto the floor slab 11 via a joist 12.

Therefore, with this invention, it is possible to significantly save on-site work, and since the compression side truss reinforcement is fixed with concrete, the cross-sectional performance of the slab is improved, making it possible to make the slab longer, and the inverted rib (beam) structure Therefore, the ceiling surface on the lower floor is flat, and piping and wiring can be installed under the floor on the upper floor.It also has a soundproofing effect and is effective for buildings such as apartments with low floor heights.

[Brief explanation of the drawing]

1 and 2 are front views of a concrete truss according to an embodiment of the present invention, FIGS. 3a and 3b are sectional views taken along line A-A in FIG. 2, and FIGS. Figure 6,
FIG. 7, FIG. 8, and FIG. 9 are explanatory views of an embodiment of the method of manufacturing a floor slab using concrete-attached trusses. 1...Reinforced truss, 2...Concrete, 3...
...Reinforced truss with concrete, 4...Slab formwork, 5...Spacer, 6...Slab reinforcement, 7...
Beam main reinforcement, 8... Beam, 9... Beam side formwork, 10...
...Cast-in-place concrete, 11...Floor slab, 12
...joist, 13...floorboard.

Claims (1)

[Scope of Claims] 1. A truss with concrete, characterized in that concrete is fixed to the convex side of the truss having a hollow. 2. A truss with concrete that is hollow and has concrete fixed to its convex side, with the concrete fixed side facing up, a slab formwork fixed to the non-concrete fixed side of the truss with concrete, and concrete fixed to the slab formwork in the same way. At the same time, the ends of the truss with concrete are fixed to the beam, and the concrete side of the truss with concrete is placed between the concrete trusses to the extent that it protrudes from the cast-in-place concrete surface. A method for manufacturing a floor slab using a truss with concrete characterized by pouring concrete.