JPH03217540A - Column and slab jointing construction in flat slab structure - Google Patents

Abstract

PURPOSE:To prevent shear fracture from being generated, and lighten weight, and facilitate work by arranging the reinforcing bars of specified lengths in a state that the bars are mounted on hoop bars arranged on a column/slab crossing section and in a state that the reinforcing bare pass the dangerous cross-sectional areas of the shear fracture. CONSTITUTION:A plurality of main bars 2a arranged vertically on a flat slab structure 1 with a column 2 set vertically on a slab 3 in the vertical direction are provided with hoop bars 26 in the horizontal direction and at specified intervals L1 in the vertical direction in a state that the main bars 2a are connected to the hoop bars 2b. After that, a plurality of the reinforcing bars 6 of length L2 are horizontally arranged in a state that the bars 6 are mounted on the respective hoop bars 26 in a cross section 1a and in a state that the bars 6 pass the cross section 1a and both the end sections pass dangerous cross- sectional area surfaces CS to be generated on the peripheries of the cross section 1a and the column 2. As a result, shear fracture is previously prevented from being generated, and weight is lightened, and handling and work are facilitated, and the reliability of the execution of the work can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a). The invention relates to a column-slab joint structure in a flat slab structure in which reinforcing members can be easily installed (b). Conventional technology Fig. 2 is a front view showing a conventional column/slab joint structure, and Fig. 3 is a plan view of Fig. 2.

Conventionally, in the flat slab structure 1, shear failure (punching failure) occurs near the intersection 1a between the column 2 and the slab 3.
Since there is a risk of this occurring, as shown in FIGS. 2 and 3, a reinforcing steel frame 5 assembled in the shape of a grid was installed to penetrate the column 2 to provide shear reinforcement.

(C). Problems to be Solved by the Invention However, the reinforcing steel frame 5 has the drawback that it is not only complicated and time-consuming to process, but is also heavy and requires a lot of manpower to install. In addition, it is not only necessary to provide special strong temporary fixing means to support the reinforcing steel frame 5 after installation until the concrete is poured, but also when concrete is poured, the reinforcing steel frame 5 must be There is a disadvantage that it is difficult for the concrete to move around the lower part, and the filling performance of the concrete at the intersection 1a is deteriorated.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a column-slab joint structure for a flat slab structure that is easy to install, lightweight, and has good concrete filling properties. It is. (d). Means for solving the problem, that is, the present invention has a slab (3), the slab (3)
A plurality of main reinforcements (2a) are provided in the vertical direction, and a plurality of hoop reinforcements (2b) are connected to the main reinforcements (2a).
In a flat slab structure (1) on which columns (2) are erected, reinforcing bars (6) of a predetermined length are placed on hoop bars (2b) provided at the column-slab intersections (1a). It is configured such that it is placed on the ground and passes through the critical cross section (CS) of punching failure.

Note that the numbers in parentheses are for convenience and indicate corresponding elements in the drawings, and therefore, this description is not limited to the descriptions on the drawings. r (e) below
．． The same applies to the column "Effect".

(e). Effect With the above-described configuration, the present invention provides that the reinforcing bars (6) are connected to the columns (
2) acts to support shear forces in the critical section (OS) of the surrounding slab (3);

(f). Example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a front view showing one embodiment of a column-slab joint structure in a flaso h-slab structure according to the present invention.

As shown in FIG. 1, the furanotoslap structure 1 has a slab 3 constructed horizontally, and columns 2 are vertically erected on the slab 3. A plurality of main reinforcements 2a are installed vertically on the pillar 2, and hoop reinforcements 2b are provided horizontally on the main reinforcements 2a at predetermined intervals L1 in the vertical direction to connect the main reinforcements 2a. (In FIG. 1, only the hoop lines 2b at the column-slab intersection 1a are shown for ease of understanding.) At the intersection 1a,
A plurality of reinforcing bars 6 having a length L2 are provided horizontally on each hoop bar 2b provided in the intersection la, and each reinforcing bar 6 has a central portion located at the intersection la. It is installed in such a way that its both ends pass through the intersection 1a and the dangerous cross section CS that occurs around the pillar 2.

Since the flat slab structure 1 has the above configuration, the reinforcing bars 6 support the shear stress that leads to shear failure occurring in the critical cross section CS of the slab 3, and prevents punching failure of the slab 3. .

(g). Effects of the Invention As explained above, according to the present invention, the slab 3 is provided,
In a flat slab structure 1 in which a plurality of main reinforcements 2a are vertically provided on the slab 3, and a pillar 2 is provided with a plurality of hoop reinforcements 2b connected to the main reinforcements 2a, the pillars 2 are erected. The reinforcing bar 6a is connected to the column/slab intersection 1a.
The intersection 1a between the column 2 and the slab 3 of the flat slab structure 1 is constructed so that it is placed on the hoop reinforcement 2b provided in The shear stress generated in the surrounding slab 3 is effectively supported by the reinforcing bars 6, making it possible to prevent punching failure from occurring.

In addition, the reinforcing bar 6 is lighter than the steel frame, and its installation is extremely easy, as the reinforcing bar 6 is simply placed on the hoop bar 2b, and the temporary fixing means can also be wire, etc. It is easy to work and can be done with a simple one.

In addition, since the reinforcing bars 6 are linear members, unlike the case where the reinforcing steel frame 5 is used, they do not block the column-slab intersection la, and can be placed in the slab 3 and intersection 1a. This prevents as much as possible from hindering the flow of concrete, and when pouring concrete, it is possible to maintain good fillability of concrete at the column-slab intersection 1a, resulting in highly reliable construction.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the column-slab joint structure in a flat slab structure according to the present invention, Fig. 2 is a front view showing a conventional column-slab joint structure, and the younger brother 3 is the same as Fig. 2. FIG. 1... Flat slab structure 1a... Intersection 2... Column 2a... Main reinforcement 2b... Hoop reinforcement 3... Slab 6... Reinforcement CS... Dangerous section

Claims (1)

[Scope of Claims] A flat slab structure with columns including a slab, a plurality of main reinforcements provided vertically on the slab, and a plurality of hoop reinforcements connected to the main reinforcements. In the above, the column and slab structure in a flat slab structure is constructed by installing reinforcing bars of a predetermined length on hoop bars provided at the intersection of the column and slab, and passing through the cross section at risk of punching failure. Slab-jointed structure.