JP3153468B2 - Construction method of concrete structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for constructing a concrete structure such as a bottom plate of an underground tank and a concrete structure.

[0002]

2. Description of the Related Art A large underground structure such as an underground tank for storing LNG or the like is constructed at a depth of about 50 m to about 60 m and a diameter of about 70 m. The bottom plate of the underground tank has a diameter of 70 m without any support and a large water pressure acts, so it is a large reinforced concrete slab with a thickness of about 10 m.

FIG. 4 is a schematic structural view of such a bottom plate 101. As shown in FIG. In FIG. 4, reference numeral 103 denotes a lower reinforcing bar, 105 denotes a middle reinforcing bar, 107 denotes an upper reinforcing bar, 109 denotes a shear reinforcing bar, 111 denotes a first concrete, 113 denotes a second concrete, and 115 denotes a first concrete 111 and a second concrete 113. Is the boundary (seam).

[0004] Reinforcing bars are arranged on the bottom slab 101 so as to resist large water pressure from the lower side.
Has a large diameter rebar of 51 mm arranged in 6 to 7 steps. Since the weight of the upper reinforcing bar 107 is large, the height is 1 in this case.
For the bottom slab of 0m, the first time concrete 111 is cast 7m,
As shown in FIGS. 6 and 7, on the upper surface of the first concrete, support bars 119 and 121 for reinforcing bars are provided.
9 and 121, the upper rebar is arranged, and the second concrete 113 is poured.

FIG. 5 is an explanatory view when the first concrete 111 is poured. Reference numeral 117 denotes a work passage / rebar support cradle. The height of the work passage / rebar support stand 117 is about 2
A work passage is provided for each m. The middle reinforcing bar 105 is arranged to prevent the upper portion of the first concrete 111 from cracking.

That is, after the lower reinforcing bar 103 and the shear reinforcing bar 109 are arranged, the work passage and the reinforcing bar support 117 are arranged.
And the middle rebar 105 is arranged with the work passage / rebar support stand 117 as a support. Then, a worker or the like passes through the inside of the work passage / rebar receiving gantry 117 and places the first concrete 111.

FIG. 6 is an explanatory view when the upper reinforcing bar 107 is arranged, and FIG. 7 is a view as seen from the direction B in FIG. After the first placement of concrete 111, 1
On the upper surface of the first concrete 111,
9 and 121 are provided, and upper and lower reinforcing bars 107 of 6 to 7 steps are arranged on the receiving stand 121, and second concrete 113 is poured.

[0008]

However, according to the conventional method, the shear reinforcing bar 109 and the pedestal 117, 1
There was a problem that workability was very poor because 19 were established. Further, since a considerable amount of steel material is used for the receiving stands 117 and 119, the cost is increased.

[0009] The present invention has been made in view of such a problem, and an object thereof is to provide good workability.
An object of the present invention is to provide a method for constructing a concrete structure capable of reducing costs.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a method of constructing a concrete structure for constructing a slab-like concrete structure by laying concrete in two parts. In the part where the first concrete is poured, a lower reinforcing bar is arranged, a plurality of shear reinforcing bars are arranged at predetermined intervals, a nut is provided at a predetermined position of the shear reinforcing bar, and an L-shaped nut is provided on the nut. A method of constructing a concrete structure, comprising: attaching steel, arranging a work passage between the L-shaped steels, arranging a middle reinforcing bar at an upper portion, and placing a first concrete.
The invention of the invention is a method of constructing a concrete structure in which concrete is cast in two parts to construct a slab-like concrete structure, comprising arranging a lower reinforcing bar and a plurality of shear reinforcing bars at predetermined intervals. Is placed, the first concrete is poured, and in the part where the second concrete is poured,
A nut is provided at a predetermined position of the plurality of shear reinforcing bars protruding above the first concrete, and a reinforcing bar receiving member is provided between the nuts so as to be supported by the plurality of shear reinforcing bars. This is a method for constructing a concrete structure, characterized by arranging an upper reinforcing bar on top and placing concrete for the second time.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. Also in the present embodiment, a bottom plate as shown in FIG. 4 is constructed. FIG. 1 is an explanatory view when the first concrete 15 of the bottom slab 1 is poured. In the present embodiment, a reinforcing bar receiver and a work passage pedestal arranged in 15 parts of the first concrete and a pedestal of a reinforcing steel bar of 31 parts of the second concrete are assembled by using the shear reinforcement 5.

In FIG. 1, 3 is a lower reinforcing bar, 5 is a shear reinforcing bar, 7 is a nut, 9 is an L-shaped steel, 11 is a middle reinforcing bar, and a shear reinforcing bar 5 is a screw reinforcing bar.
They are arranged at intervals.

The lower reinforcing bar 3 is arranged, and the shear reinforcing bars 5 are arranged at intervals of 1 m to 2 m. Since the shear reinforcement 5 is a screw reinforcement, the nut 7 can be screwed into an arbitrary position.
An L-shaped steel 9 is attached to the nut 7 by welding or the like. Then, the work passage 13 is arranged between the L-shaped steel members 9, and L
The middle rebar 11 is arranged on the section steel 9. Then, the first concrete 15 is cast. Reference numeral 17 denotes a boundary (seam) between the first concrete and the second concrete. In the case of FIG. 1, the boundary 17 is the upper surface of the first concrete 15.

FIG. 2 is an explanatory view when the upper rebar 29 is arranged, and FIG. 3 is a view as seen from the direction A in FIG.
When the first concrete 15 has been placed, the shear reinforcement 5 protrudes from the boundary (upper surface) 17 of the first concrete 15. A nut 21 is screwed into the shear reinforcing steel bar 5 and reinforcing steel materials 23 and 25 are attached between the nuts.
7 is attached. Then, the upper rebars 29 of six to seven steps are arranged on the rebar receiving hardware 27. Furthermore, the second concrete 31 is cast to construct the bottom slab 1.

As described above, in this embodiment, since the shear reinforcing reinforcing bar 5 is used as a support of the working passage, the middle reinforcing bar 11 and the receiving stand of the upper reinforcing bar 29, the working passage and reinforcing bar receiving stand 117 are separately provided as in the related art. It is not necessary to provide the receiving stand 119. That is, the workability was poor because the shear reinforcement bars and the receiving stand were standing in the past, but in the present embodiment, the conventional receiving stands 117 and 119 are unnecessary by using the shear reinforcing bars 5 as the receiving stand. And workability is also improved. In addition, receiving stands 117, 11
The number of temporary steel materials for No. 9 can be reduced, and the cost can be reduced.

[0016]

As described in detail above, according to the present invention, it is possible to provide a method of constructing a concrete structure which has good workability and can reduce the cost.

[Brief description of the drawings]

FIG. 1 is an explanatory view when the first concrete 15 is poured.

FIG. 2 is an explanatory view when the upper reinforcing bar 29 is installed.

FIG. 3 is a view as seen from an arrow A in FIG. 2;

FIG. 4 is a diagram showing a schematic configuration of a bottom plate 101

FIG. 5 is an explanatory view when the first concrete 111 is poured.

FIG. 6 is an explanatory view when the upper reinforcing bar 107 is installed.

FIG. 7 is an arrow view from the direction B in FIG. 6;

[Explanation of symbols]

 1 Bottom slab 3 Lower reinforcing bar 5 Shear reinforcing bar 7 Nut 11 Middle tier 15 First concrete 21 Nut 27 Metal fitting 29 ……… upper bar 31 …… the second concrete

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E02D 29/045-29/055 E04G 21/12 E04C 5/00-5/20 E02D 27/38 E04H 7 / 18

Claims (3)

(57) [Claims] 1. Concrete is poured in two separate times,
Concrete for building slab-like concrete structures
In the method of constructing a structure, the part where the first concrete is cast
Arrange, arrange a plurality of shear reinforcement at predetermined intervals, provide a nut at a predetermined position of the shear reinforcement,
Attach the L-shaped steel to the nut and pass the work between the L-shaped steels.
A road is laid, a middle reinforcing bar is laid at the top, and the first concrete is cast.
How to build a cleat structure. 2. Casting concrete in two parts
Concrete for building slab-like concrete structures
A method of constructing a structure, comprising arranging a lower reinforcing bar and forming a plurality of shear reinforcing bars at predetermined intervals.
In the part where the concrete is placed and the first concrete is poured,
A plurality of the above-mentioned shear reinforcement protruding above the concrete
A nut is provided at a predetermined position on the reinforcing bar, and a reinforcing bar is provided between the nuts.
Set the receiving hardware so that it is supported by multiple shear reinforcing bars.
And a second concrete is placed by placing an upper rebar on the rebar receiving hardware.
How to build a cleat structure. 3. A part for placing concrete for the second time
In other words, a reinforcing material is provided between the plurality of reinforcing steel bars.
3. The concrete according to claim 2, wherein
How to build the structure.