JPS6138299B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel assembled steel reinforced semi-precast concrete slab, a method for manufacturing the same, and a slab construction method using the same.

Recently, there has been a demand for long span slab systems in apartment complexes, supermarkets, etc.

In response to this type of need, a slab construction method using semi-precast concrete plates reinforced with prefabricated reinforcing bars that can also be used as formwork has already been developed. It was impossible to construct the span without support due to insufficient bending strength and bending rigidity.

The present invention has been made in view of the above-mentioned circumstances in order to realize an unsupported length span slab construction method, and the details thereof will be explained below based on the drawings.

First, the gist of the assembled reinforcing bar-reinforced semi-precast concrete version of the present invention is that in the conventional assembled reinforcing bar-reinforced semi-precast concrete version 1 shown in FIG. Although it is involved in the bending strength, we focused on the fact that it does not contribute much because the degree is related to the cross-sectional area of the upper chord muscle, and as shown in Figure 2, the upper chord muscle 2a is supported by a precast concrete block 3 with a predetermined cross section, and its cross-sectional area is greatly increased. The bending strength and bending rigidity of the slab can be greatly increased without requiring any changes, and the unsupported length span slab construction method has become possible.

The assembled reinforcing reinforcing semi-precast concrete slab 6 of the present invention constructed as described above was used in the first and second
The following describes the results of a design using the dimensions shown in the figure and a performance comparison between the two.

That is, assuming Young's modulus is 7.56, for conventional plate 1, stiffness I = 2208 (cm ⁴ ) section modulus on the tension side Z _t = 669 (cm ³ ) section modulus on the compression side Z _c = 211 (cm ³ ) Regarding plate 6 of the present invention, I = 6767 (cm ⁴ ) Z _t = 1514 (cm ³ ) Z _c = 587 (cm ³ ), and compared to the conventional one,
The rigidity is approximately 3 times higher, the tension side section modulus is 2.25 times, and the compression side section modulus is 2.5 times, making it possible to temporarily install without support even over long spans.

Further, the results of the bending experiments for both are shown graphically in FIG.

A method of manufacturing the plate of the present invention having the above configuration will be described below.

First, as shown in Fig. 4, the lower end reinforcement 4 and the assembly reinforcement 2 are placed on the bed 7, as in the conventional one.
Next, the steel plate form 8 for configuring the precast concrete block 3 is assembled at a predetermined position of the assembly reinforcing bar 2, and then the concrete layer 5 and the block 3 are poured. It is something.

Incidentally, after solidification, the iron plate form 8 may be removed from the mold or may be left as is.

Part 2 is as shown in FIGS. 5a and 5b, first, a bed 10 is provided with partition walls 9, . . . for forming blocks.
With the assembled reinforcing bars 2 held upside down and placed on top, concrete is poured for block 3,
A combined body 11 of assembled reinforcing bars 2 and blocks 3 is made,
(Fig. a) Next, this combined body 11 is assembled to the lower reinforcement 4 placed on the bed 7, and then concrete layer 5 is poured (Fig. b).

A slab construction method using the assembled reinforcing reinforcing semi-precast concrete slab 6 of the present invention described above will be explained with reference to FIG. 6, which shows its cross-sectional configuration.

Figure a shows the case where the plate 6 is housed in the slab,
In the figure, reference numeral 12 indicates the slab top reinforcement placed on the block 3 of the slab 6 installed adjacent to the beam, and reference numeral 13 indicates the post-cast concrete layer that will be placed afterwards.

Incidentally, 14 indicates a hollow portion which may be provided as needed.

In addition, Figure b shows the case where the top of the plate 6 is the top of the slab. In this case, although not shown, the reinforcement of the upper end reinforcement 12 as shown in Figure A is placed in a predetermined manner at /4 of the peripheral edge of the slab. This must be done while ensuring the thickness of the cover.

As described above, according to the present invention, an unsupported long span slab construction method becomes possible.

[Brief explanation of the drawing]

FIGS. 1 and 2 are longitudinal cross-sectional views of a conventional semi-precast concrete plate reinforced with reinforcing steel according to the present invention, and FIG.
The figure is a graph of a bending experiment, FIGS. 4 and 5 are diagrams explaining the plate manufacturing procedure of the present invention, and FIG. 6 is a diagram explaining the slab construction method of the present invention. 2... Assembly reinforcing bar, 2a... Top chord bar, 3... Concrete block, 2b... Bottom chord bar, 4... Bottom end bar, 5... Concrete layer, 7... Bed, 8... Iron plate formwork, 10
... Bet, 11... Combined body, 12... Upper end muscle, 13...
Post-cast concrete layer.

Claims (1)

[Scope of Claims] 1. A semi-precast concrete plate reinforced with prefabricated reinforcing bars, characterized in that a precast concrete block of a predetermined cross section is supported by the top chord of the prefabricated reinforcing bars. Edition. 2. Place the lower end reinforcement and assembly reinforcing bars on the bed, then assemble the steel plate formwork for configuring the precast concrete block at the predetermined position of the assembly reinforcing bars, and then start pouring concrete for the slab part and the block. A method for manufacturing an assembled reinforcing bar reinforced semi-precast concrete block comprising a precast concrete block having a predetermined cross section held by the top chord of an assembled reinforcing bar. 3 Place the assembled reinforcing bars in an upside-down position on a bed with a partition wall for forming a concrete block, and pour concrete for the block to create a combination of the assembled reinforcing bars and the block. Next, the combined body is assembled to the lower end reinforcement placed on the bed, and the slab portion is then concreted. A method for manufacturing semi-precast concrete plates reinforced with prefabricated reinforcing steel. 4 An assembled reinforcing reinforcing semi-precast concrete block consisting of a precast concrete block of a predetermined cross section held by the top chord of the assembled reinforcing steel is erected adjacently between the beams as a waste form, and the top chord of the predetermined slab A semi-precast reinforced semi-precast reinforced concrete structure in which a precast concrete block of a predetermined cross section is supported by the top chord of the assembled reinforcing steel, characterized in that after the reinforcing bars have been placed, post-cast concrete is poured into the slab. Unsupported length span slab construction method using concrete slabs.