JPS611765A - Reinforcing structure of concrete structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to wall surfaces and floors in reinforced concrete structures
The invention relates to a reinforcement structure for flat plate-like members such as plates.
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[Prior art and its problems]

In conventional reinforced concrete construction, drying and shrinkage of the concrete was the main cause of cracks in flat plate-like members such as walls and floor slabs, which are surrounded by columns and beams and whose cross-sectional area changes rapidly. As countermeasures to this problem, two methods were used: one is to reduce the amount of concrete shrinkage through concrete mix design, such as the use of admixtures, and the other is to distribute reinforcement by arranging reinforcement on walls and floor slabs. Fig. 9 and Fig. 9 are drawings showing the reinforcing bar arrangement and the state of cracks in a conventional general wall and floor spa, and Fig. 1O shows the state of the reinforcing bar arrangement and cracks. FIG. In Fig. 8, the wall surface 50 between the pillars 51 and 52 is conventionally covered with reinforcing bars 53 and reinforcing bars are stretched across the pillars 51 and 52, but in reality, there is a wall near the center of the wall surface 50 in the direction of the pillars 51 and 52. Cracks 54 parallel to the pillars 51 and 52 and the wall surface 5 are generated as shown in the cross-sectional view of FIG.
Diagonal cracks 51 are also seen at the 00 person corner portions 55 and 56. For the floor slab 60 in FIG. 9, the beam 6ta,
s1b.

Reinforcement bars 63a, 6 parallel to and orthogonal to 62a, 62b
In this case, beams 61a and 61b are installed near the center of the floor slab 60, respectively.

Reinforcing bars 63a are parallel to 62a and 62b, respectively.

Cracks 64a and 64b perpendicular to 63b were observed, and also cracks 61a and 61b, respectively.

62a, 62b and the inner corner of floor stripe pro 0 also have the 10th
Cracks similar to the cracks 57 on the wall surface 54 in the figure are observed, and the current situation is that the effect of the reinforcing bars as reinforcing bars is not fully demonstrated in either case.

This means that the wall surface 50t or the floor slab 60 is constrained at its υ sides by the columns 51, 52 or beams 61a, 161b, 62a, and 62b, and the reinforcing bars 53, 63&.

Since abdominal reinforcement is used for 63b, the reinforcement 53, 63a can withstand the tensile force that occurs when concrete dries and shrinks.
, 63b, there is insufficient adhesion between the two, resulting in slippage at the interface.

There is a proportional relationship between concrete strength and adhesion), but when concrete is in its initial stage, its strength and adhesion are not fully developed, but when this is observed in an actual building, , cracks occur during the initial stage of concrete 2 to 5 days after concrete placement.
This phenomenon indicates that drying shrinkage of the concrete has already begun at the time of initial material age, and it also confirms that the weak adhesion between concrete and reinforcing bars is one of the causes of cracks. ing.

[Purpose of the invention]

This invention was developed in view of the above-mentioned structural defects, and it is possible to create a reinforced concrete structure by using reinforcing bars with end shapes that have a binding force on concrete, and by stretching the ends of the reinforcing bars onto columns or beam structures. The present invention provides a reinforcing structure that prevents cracks in wall surfaces or floor slabs, as well as large corners, and improves the quality of concrete structures.

[Structure of the invention]

In a wall or floor slab of the present invention whose sides are connected and supported by pillars or beam structures, 1800 or more bent portions are provided at both ends of the reinforcing bars, and 300 to 450 bent portions are further provided from the center of the bent portions, This is a reinforcing structure for a concrete structure, characterized in that reinforcing bars to be fully stretched are placed and buried in a wall or floor slab at a bent part that penetrates a column or beam expansion structure.

〔Example〕

Embodiments of the present invention will be explained with reference to the drawings. FIGS. 1 to 4 are front views showing the bent portions of reinforcing bars and the aspect of the bent portions, and FIG. Part 2a,
2b, and further a straight part 4 which is constant from the bent parts 2a and 2b.
1B, 41b, and a reinforcing bar 1 provided with a bent part 45&, 45b having a bending angle of 300 to 450 at the center;
In FIG. 2(A), 27,000 bent portions 4at4b are provided, and the same straight portions 4.2''t42b and bent portions 46&, as in FIG.
Fig. 3 (A) shows a reinforcing bar 30 with bent parts 4a and 4b whose tips are further lengthened.
, '-6b are provided, and a straight portion 431L similar to that in FIG.
Reinforcement bar 5 with bent portions 43b and 47a, 47b, fourth
Figure (A) shows a reinforcing bar 7 with a bent part 8ap8b formed by further bending the bent parts 5a and 5b of the reinforcing bar 5 to 360 degrees, and with straight parts 44 &, 44b and bent parts 4g &, 48b similar to those in Fig. 1. It is.

Figure 1 (B), Figure 2 (B), Figure 3 (B), Figure 4 (
B) is a detailed view of each bending part 2a, 4a, 6a, 8a.
, and FIG. 4(C) are A-A in FIG. 4(B), respectively.

It is a side view of the bending part seen from BB, CC, and DD.

FIG. 5 is a partially cross-sectional perspective view showing the reinforcing bars 13 placed and buried in the wall surface 10 supported on two sides by columns 11 and 12, and FIG. This is the reason. In this embodiment, the bent portions 1a and 2b and the bent portions 45 & 45 explained in FIG.
The reinforcing bar 13 has a bent part 15 at the tip and a bent part 1 from the center of the bent part 15.
4, the bent part 15 at the tip penetrates into the structure of the pillars 11 and 12, and the straight part 16 between the bent part 14 and the bent part 15 is connected to the pillar 11.
．． The inside corner 17 formed at the contact point between the corner 12 and the wall surface 10 is placed and buried in the wall surface 10 so as to be perpendicular to the direction of the bisector of the corner angle. 22a.

Reinforcement bars 2 perpendicular to the floor slab 20 supported by 22b
4.25 is a partially sectional perspective view showing a state in which the 4.25 is placed and buried. In this embodiment as well, the reinforcing bars 24 and 25 having the bent portions 2a and 2b and the bent portions 45 and 45b as explained in FIG. 1 are used. 28, 29, and a bent part 26 at the center of the bent part.
．． 27, and the bent portions 28 and 29 at the tips are the beams 21a and 2.
1b, 22a, 22b structure and bends 26.27
The straight parts 3.0 and 31 between the curved parts 28 and 29 are the seventh
The 6 beams 21a, 2
1b, 22a.

22b and the large corner 32 formed at the contact point of the floor slab 20.
33 is placed and buried in the floor slab 20 so as to be perpendicular to the direction of the bisector of the corner angle.

[Action of the invention]

In order to prevent cracks in concrete structures, the contact area between the concrete and the reinforcing bars is the dominant factor, and this technical concept can be applied as a fixing ability when the concrete reaches a predetermined strength. However, at the initial age of the concrete, the projected area of the reinforcing bars in the direction of drying shrinkage of concrete has resistance to shrinkage.
Furthermore, reinforcing bars, bent portions at both ends, and reinforcing bars having fixed shapes that have high rigidity against deformation at bent portions are extremely effective in preventing cracks.

In the present invention, both ends of the reinforcing bars are bent by 1,800 degrees or more to provide high rigidity against undoing and slipping due to tensile force, and the bent portions have a large projected area in the direction of drying shrinkage of concrete. In addition, the reinforcing bars are provided with bent portions so that the bent portions can be effectively penetrated and fixed into highly rigid structures such as columns and beams, so that they act extremely effectively as reinforcement against cracks. At the same time, for cracks in large corners, by appropriately selecting the bending angle of the bent part and the length of the straight part, reinforcement can be arranged at right angles to the bisector of the corner. This provides a reinforced structure that is also effective in preventing cracks.

〔Effect of the invention〕

As explained above, the reinforcing structure of the present invention has a simple structure and is effective in preventing cracks in large corners and on the surfaces of walls and floor slabs, not only at the initial stage but also after solidification. In addition, since the shape is extremely simple, it is easy to fill with concrete, and by arranging reinforcing bars with different end lengths, the structure is even more strongly stretched and effectively prevents cracks. It becomes a reinforced structure.

[Brief explanation of the drawing]

Figure 1 (A), (B), (C) to Figure 4 (A
), (B), and (C) are a front view, a detailed view of a bent part, and a side view showing four types of reinforcing bars, and FIG. Figure 6 is a partial cross-sectional perspective view showing the reinforcement arrangement of the floor slab between the beams, Figure 7 is a sectional view showing the reinforcement arrangement of the wall surface, and Figure 8 is the conventional wall reinforcement arrangement and the state of cracks. FIG. 9 is a plan view showing the reinforcement arrangement and cracks in a conventional floor slab, and FIG. 10 is a cross-sectional view showing the reinforcement arrangement and cracks in a wall surface. 1.3, 5, 7, 13, 24, 25... reinforcing bar 2at2
b+4at4b+6't6bt8"+8b, 15
, 28, 29...Bending portion 10...Wall surface
11.12-...Column 14.26, 27°45B,
45b, 41, 46b, 47&. 47 b, 48 a, 48 b --- bent part 16°3G, 31.41a, 41b, 42a, 42
b. 43 & , 43 b , 44 a , 44 b
...Straight section 17.32.33...Inner corner section 20
... floor sump 2.1 & , 2 l b , 22
a, 22 b... Beam No. 6 #A Fura No. 7 m Purchase 811

Claims (1)

[Claims] In a wall or floor slab whose sides are joined and supported by pillars or beam structures, a bent portion of 180° or more is provided at both ends of the reinforcing bars, and a bent portion of 30° to 45° is provided from the center of this bent portion. This is a reinforcing structure for a concrete structure, characterized in that a bent part is provided, and reinforcing bars, which are stretched by the bent part penetrating the column or beam structure, are arranged and buried in the wall or floor slab.