JPS6012500B2 - Construction method of reinforced concrete frame frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a reinforced concrete key frame.

Reinforced concrete IJ in reinforced concrete frame frame
It has become clear that the pillars of the main deck are easily destroyed by large earthquakes using the conventional reinforcement arrangement method, and in order to improve this,
Improvements have been made such as increasing the number of hoop reinforcements for the main reinforcing bars of columns and adding innovation to the saddle arrangement of rectangular hoop reinforcements. However, in general, in a rectangular column made of reinforced concrete, the restraining action of the hoop reinforcement does not work sufficiently in terms of the cross section, so it is not easy to improve the strength and deformability of the column. On the other hand, spiral circular hoop reinforcements or closed circular hoop reinforcements have an extremely large restraining effect on the core concrete surrounded by the main reinforcing bars and hoop reinforcements.
A reinforced concrete cylinder using this material has significantly superior strength and deformability compared to a general reinforced concrete rectangular column. In general, in reinforced concrete columns where axial force, bending moment and shear force act,
The apparent volume of the core concrete surrounded by the hoop reinforcements and main reinforcing bars expands due to cracks, etc., and the main reinforcing bars surrounded by the hoop reinforcements also deform in a direction perpendicular to the material axis. Spiral and closed circular hoop reinforcements resist this behavior by their tensile force, and therefore exhibit a significant restraining effect on the deformation of the core concrete and main reinforcing bars of the cylinder. On the other hand, rectangular hoop reinforcements used in rectangular columns have a higher degree of restraint than circular hoop reinforcements due to their shape against expansion of the core concrete and spreading of the main reinforcing bars, that is, deformation. drop during. This difference in the degree of restraint has a great influence on the quality of reinforced concrete columns. On the other hand, circular columns are less common than rectangular columns in terms of architectural design or how they fit into walls and interiors. The present invention incorporates the strength and deformability of the commonly used reinforced concrete rectangular column into the rectangular column in the construction of a reinforced concrete frame frame, and incorporates into the rectangular column the above-mentioned characteristics of a circular column using spiral or closed circular hoop reinforcement. The aim is to improve this by eliminating the defects that arise as by-products, and to provide a new, safer construction method for reinforced concrete frame frames.

That is, ``the first invention of the method for constructing a reinforced concrete frame of the present invention is to arrange the main reinforcing bars 2 of the pillar turtle along a circular design cross section, as illustrated in Figures 3 to 3. At the same time, a spiral or closed type circular hoop reinforcement 3 is arranged on the outer periphery of the reinforcement, and the above-mentioned joint reinforcement is arranged so that a reinforced concrete cylinder 4 having a predetermined concrete cover thickness d is built into the outer periphery of the reinforcement. A reinforced concrete rectangular column 5 is constructed by pouring concrete into a square or rectangular cross section of a shape close to this, and when constructing the rectangular column 5 described above, the beams 6 on the upper and lower floors of the rectangular column 5 are A slit-shaped void portion 8 is formed in the concrete cover portion 7 corresponding to the outer portion of the predetermined cover thickness d of the concrete of the above-mentioned cylinder 4 in the end cross section joining with the above-mentioned slit. It is characterized by filling or inserting a soft material into the shaped cavity 8.
The outer cross section of the reinforced concrete column of the key rigid frame constructed by the above construction method is rectangular, and although it looks like a rectangular column 5, the substance of the reinforced concrete column is that it has a cylindrical effect and is formed by spilling or closing inside the rectangular column 5. It has a built-in reinforced concrete column 4 that surrounds main reinforcing bars 2 arranged in a circle with circular hoop bars 3.

However, in the configuration in which the slit-shaped void 8 is not formed, the concrete of the compression castle is likely to fail at the critical cross section of the rectangular column 5, that is, generally at the end cross section where the rectangular column 5 connects with the beams 6 on the upper and lower floors. This has an important influence on the behavior of the rectangular column 5. That is, in a column to which an axial force acts, in combination with the compressive stress transmitted by the bending moment, compression bonding of the concrete occurs before and after the tensile yield of the main reinforcing bars 2. Particularly in columns with large rolling forces, unstable behavior is exhibited after the concrete collapses. In addition, in a rectangular column 5 that has a built-in column 4 in which the main reinforcing bars 2 arranged along a circle are surrounded by circular hoop reinforcements 3, the ratio of the area of the concrete covering part 7 to the whole cross section is large, and the pressure of the concrete in this part is large. Dense spalling causes a drawback in that the yield strength of the column is significantly reduced. The present invention aims to improve this drawback by adding a predetermined cover of the concrete of the column 4 at the critical cross section of the rectangular column 5 described above, that is, generally at the end section where the rectangular column 5 connects with the beams 6 on the upper and lower floors. A slit-shaped cavity 8 is formed in the concrete cover part 7 corresponding to the outer part of the concrete cover part 7 while leaving a thickness d (see Figs. 1 and 2), and a large compressive stress acting on the concrete of the cover part 7 is formed. The structure is such that the area of the crushed portion is reduced. In this case, the stress that should originally be borne by the cover portion 7 is transmitted to the compression main reinforcing bars and the rest of the concrete, but buckling of the main reinforcing bars 2 does not occur because the restraining force of the circular hoop reinforcements 3 is large. Therefore, except for the above-mentioned end cross section which is the dangerous cross section, the column remains a rectangular column, and the concrete's ability to bear shear force is greater than that of a rectangular column with the same cross-sectional area as the cylinder in the dangerous cross section. As mentioned above, in the method of constructing a reinforced concrete frame frame of the present invention, the influence of the concrete compression bond of the reinforced concrete column is reduced in response to bending moment, and the characteristics of the reinforced concrete column are maintained. The middle part between the upper and lower floors of the column is a rectangular column, which can satisfy design and construction requirements.

However, according to the construction method of the present invention, the reinforced concrete column can maintain sufficient strength and large deformability, unlike general conventional rectangular columns, even under Takafuji pressure that exceeds the balance key force. It is. As shown in FIGS. 5 and 6, the slit-shaped void 8 is filled with a soft material 9 due to the finish of this part of the structure, fire resistance, etc.
to be filled or inserted.

Incidentally, in pouring concrete for the columns, it is also possible to set the gill material 9 in advance in the formwork. Furthermore, as illustrated in FIG. 4, the cover portion 7 of the rectangular column described in the above-mentioned construction method is provided with vertical reinforcing bars 10 with a relatively small diameter that are unrelated to the burden of the principal stress, mainly to reinforce the spalling of this portion. In actual construction, it is desirable to arrange reinforcing reinforcing bars for the horizontal reinforcing bars i1 or both. Next, the second invention of the method for constructing a reinforced concrete frame frame of the present invention is as follows:
As illustrated in Fig. 7, the main reinforcing bars 2 of the columns are arranged along the outer edge of a double-circular design cross section in which multiple circles continue in one direction, with some overlapped, and in each of the above circles. On the other hand, spiral or closed circular hoop reinforcements 3 are arranged so that the main reinforcing bars 2 along the circle are inscribed, and reinforced concrete with a predetermined concrete cover thickness d' is placed around the outer periphery of the reinforcement. In order to create a built-in double cylinder column 12 (in this case two cylinders partially overlapping each other), concrete is poured into a rectangular cross section surrounding the above-mentioned reinforcement to form a reinforced concrete rectangular column 5'. and when constructing the rectangular column 5' described above, a predetermined cover thickness d of the concrete of the double circular column 12 is applied at the end section where the rectangular column 5' joins the beams on the upper and lower floors. 'A slit-shaped cavity 8' is formed in the concrete covering part 7' which corresponds to the outer part of ', and the above-mentioned slit-shaped cavity 8 is
' is characterized by filling or inserting a soft material.

In addition, in the concrete cover part 7' of the rectangular column 5',
It is desirable to arrange reinforcing reinforcing bars, such as longitudinal reinforcing bars or transverse reinforcing bars, or both, which have a relatively small diameter and are unrelated to the burden of principal stress. In the first aspect of the present invention, in the structure of a reinforced concrete frame frame, when a rectangular column needs to have a rectangular cross section for design or structural mechanics reasons, the outside part of the gate post 4 is placed on both sides of the rectangular column in the longitudinal direction. This creates a large concrete cover, which is both uneconomical and structurally inconvenient.

This second invention has a multi-cylindrical column 12 built into the rectangular rectangular column 5'.
The second invention can eliminate the drawbacks of the construction method of the invention in which the use of concrete for columns becomes uneconomical and causes structural inconvenience. Note that the second invention naturally has the same effects as the first invention.

[Brief explanation of the drawing]

The attached drawings are for explaining aspects of the present invention by way of examples, and FIGS. 1 to 6 show the first invention of the present invention, and FIG. 1 is a side view of a reinforced concrete column according to the first invention.
Figure 2 is a cross-sectional view taken along line A-A in Figure 1, Figure 3 is a cross-sectional view taken along line B-B in Figure 1, and Figure 4 corresponds to Figure 3. It is a cross-sectional view showing two examples in which reinforcing reinforcing bars are arranged in the overlapping portion. Next, Fig. 5 is a side view of the main part of the reinforced concrete column according to the first invention, and shows a case in which soft material is filled or inserted into the slit-shaped void, and Fig. 6 is a side view of the main part of the reinforced concrete column according to the first invention.
- It is a cross-sectional view along the C line. Next, FIG. 7 is a cross-sectional view of a slit-shaped cavity of a reinforced concrete column according to the second aspect of the present invention. 1... Column, 2... Main reinforcing bar, 3... Circular hoop bar, 4... Cylinder, 5, 5'...
Rectangular column, 6... Beam, 7, 7'... Cover part, 8,
8'...Gap, 9...European material, '0...Vertical reinforcing bar,
11...Horizontal reinforcement, 12...Double cylinder, d, d'...Predetermined cover thickness. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. The main reinforcing bars of a column are arranged along a circular design cross section, and spiral or closed circular hoop reinforcements are arranged around the outer periphery of the reinforcing bars. A rectangular column of reinforced concrete is created by pouring concrete into a square or rectangular cross-section of a shape close to this, surrounding the above-mentioned reinforcement so that it has a built-in reinforced concrete column having a cover thickness; When constructing a rectangular column, a slit-shaped slit is placed in the concrete cover part that corresponds to the outer part of the predetermined cover thickness of the concrete of the above-mentioned column at the end cross section where the rectangular column connects with the beam on the upper and lower floors. 1. A method for constructing a reinforced concrete frame frame comprising: forming a void, and filling or inserting a soft material into the slit-like void. 2 The main reinforcing bars of the columns are arranged along the outer edge of a double circular design cross section in which multiple circles continue in one direction, with some overlapped, and the main reinforcing bars are arranged along the circle for each of the above circles. Spiral or closed circular hoop reinforcements are arranged so that they are inscribed in each, and the above reinforcement arrangement is such that a double cylinder of reinforced concrete with a predetermined concrete cover thickness is built in around the outer periphery of the reinforcement arrangement. A reinforced concrete rectangular column is created by pouring concrete into a rectangular cross section encasing the rectangular column, and when constructing the above rectangular column, the above-mentioned A slit-like void is formed in the concrete cover part that corresponds to the outer part of the predetermined cover thickness of the double cylinder concrete, and the above-mentioned slit-like void is filled or filled with a soft material. A method for configuring a reinforced concrete frame frame characterized by inserting.