JPS5873650A - Apparatus for reinforcing opening 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 The present invention relates to an opening reinforcement device for a reinforced concrete structure, a steel-framed reinforced concrete structure, or a prestressed concrete structure (hereinafter referred to as a reinforced concrete structure, etc.). The present invention relates to a reinforcing device for an opening such as a duct.

Conventionally, when arranging an opening such as a duct in a reinforced concrete structure, in order to reinforce the strength of the structure at the opening, reinforcing reinforcing bars were placed densely around the opening in addition to regular reinforcing bars. The striation method has been widely used. This conventional construction method had drawbacks such as regular reinforcing bars, especially main bars, and reinforcing bars being intricately intertwined, making it difficult to install reinforcing bars, resulting in insufficient concrete surrounding the concrete and prolonging the construction period. Furthermore, in the case of beams of steel-framed reinforced concrete structures, it is also known to attach a steel plate or the like to a normal steel member of a duct penetration part and to fix the steel plate to a sleeve by welding or the like. However, in conventional construction methods that use steel plates, the dimensions of the reinforcing steel plates are usually determined by the arrangement of the steel members, so the amount of reinforcing steel plates becomes quite constant, which significantly increases the amount of steel used. However, there were drawbacks such as the need for skilled workers for a long time to weld the steel frame members and reinforcing steel plates at the construction site.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art all at once by providing an improved opening reinforcement device for reinforced concrete structures and the like.

In order to achieve the above object, the opening reinforcement device for reinforced concrete structures, etc. according to the present invention includes a hollow steel cylindrical member, a steel plate member integrally connected to the outer surface of the peripheral wall of the cylindrical member, and a steel plate member from the periphery of the steel plate member. It is characterized by having a protruding rod-like projection.

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This rod-shaped projection may be used in place of the fixing part of the cross-section reinforcement, it may be connected to the main reinforcement of the crotch section, or it may be welded to the steel beam.

In a preferred embodiment of the present invention, the cylindrical member, the steel plate member, and the rod-shaped projection are integrally formed by casting or welding. Furthermore, portions of the steel plate member that are unnecessary in terms of strength may be removed. Preferably, the cylindrical member is cylindrical.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1st
The figure shows a plan view of one embodiment of the present invention, and FIG. 2 shows a cross section taken along the line 1--H in FIG.

The opening reinforcing device 1 of this embodiment includes a rectangular steel plate member 3 integrally coupled to the outer surface of the peripheral wall of a hollow cylindrical member 2 made of steel, and a rod-shaped protrusion protruding from the periphery of the steel plate member to the side opposite to the cylinder member 2. It has 4. The cylindrical member 2 is formed, for example, by casting or cutting a seamless tube. The cross-sectional shape of the cylindrical member 2 is not limited to a circular shape, but may be rectangular, polygonal, Th, etc., depending on the shape of the opening of a reinforced structure such as a duct, etc. Any other cross-sectional shape may be used. □: The steel plate member 3 functions as a reinforcing bar that has been commonly used in the past, and whereas the reinforcing steel plate in the above-mentioned steel reinforced concrete structure had a shape determined by the arrangement of steel frames. The shape and thickness of the steel plate member 3 according to the present invention are determined in consideration of the flow of force acting on an opening in a reinforced concrete structure or the like to be reinforced. Preferably, as shown in FIG. 1, a portion of the steel plate member 3 that does not require strength -L is removed to reduce the amount of the opening reinforcing device 1. The steel plate member 3 can be integrally formed with the cylinder member 2 or can be integrally connected to the cylinder member 2 by welding. Further, the steel plate member 3 is arranged in a direction perpendicular to the central axis C of the cylindrical member 2, as shown in FIG. be combined.

The rod-shaped protrusion 4 is for facilitating the connection between the opening reinforcing bag arrangement and the reinforcing bars or steel frame (not shown) of the structure.
It is arranged so as to protrude from the periphery of the steel plate member 3 to the opposite side of the cylindrical member 2 on the surface of the steel plate member 3, that is, on a plane perpendicular to the above-mentioned central axis C. The rod-shaped projection 4 is, for example, cast integrally with the cylindrical member 2 and the steel plate member 3, or is integrally connected to the steel plate member 3 by welding.

Fig. 3 shows an embodiment in which the steel plate member 3 is made circular and parts unnecessary for its strength are removed, and Fig. 4 shows an embodiment in which the cylindrical member 2 has a rectangular cross section and the steel plate member 3 is rectangular. .

In use, the opening reinforcing member l is attached to a concrete formwork (not shown) so that the cylindrical member 2 itself serves as an opening for a duct, etc., or attached to a separately attached opening forming member (not shown). The cylindrical member 2 is coupled. Thereafter, the rod-shaped projection 4 is connected to the reinforcing bars or steel frame (not shown) of the structure by welding, bending, or other known connection methods. Then, if concrete is laid by a known method, a strongly reinforced concrete structure opening will be formed.

In the illustrated embodiment, the steel plate member 3 is disposed perpendicular to the central axis C of the cylindrical member 2, but the steel plate member 3 may be arranged at a suitable angle with respect to the cylindrical member 3, if necessary.

Alternatively, the steel plate member 3 itself may be appropriately bent.

Hereinafter, the present invention will be explained in more detail with reference to Example 1.

! LL The first opening reinforcement device for a circular opening in a reinforced concrete structure in which reinforcing bars with a nominal diameter of 32 mm are arranged vertically and horizontally.
As shown in the figure, the steel plate member 3 is made into a square, and its detailed shape is determined as follows.

i. The thickness of the steel plate member 3 is determined based on the calculation results of the load stress. If the load stress cannot be calculated, the thickness of the steel plate member 3 can be set to 16 mm or more, which is half the diameter of the main reinforcement.

11. Determine the length of one side of the square steel plate member 3 based on the calculation result of stress concentration distribution. If the stress concentration distribution cannot be calculated, the length of one side of the square steel plate member 3 can be set to about twice the diameter of the opening in the reinforced concrete structure to be reinforced.

Step 111: Determine the required cross-sectional area of the square steel plate member 3 based on the stress distribution calculation results 1. Remove unnecessary portions from the viewpoint of strength as shown in FIG. If the stress distribution cannot be calculated,
The cross-sectional area of the ring-shaped portion of the steel plate member that is in contact with the tube-shaped section in Figure 1 is 23.82 cm (= 3
X 7.94) With the above, the cross-sectional area of the vertical and horizontal band-like parts on the outside of the ring-like part in Figure 1 can be made larger than the total cross-sectional area of the horizontal reinforcement and vertical reinforcement of the reinforced concrete structure.

1v, the cross-sectional area of each rod-shaped projection 4 is the cross-sectional area of the main reinforcement 7.94c
m or more, the interval between the bar-shaped protrusions 4 is determined based on the interval between the main bars, and the length of the bar-shaped protrusion 4 is determined in consideration of connection with the reinforcing bars.

The opening reinforcing device 1 having the shape and dimensions determined as above is cast.

The effects obtained by the aperture reinforcing device of the present invention having the structure described above are listed below.

(1) Since there is no need to arrange reinforcing bars at the construction site, complicated on-site reinforcement work can be omitted.

(2) Any shape of opening can be easily accommodated simply by selecting the shape of the cylindrical member.

(3) Even if the stress concentration is large, it can be easily dealt with simply by increasing the thickness of the steel plate member or adding reinforcing ribs to the steel plate member.

(4) An aperture reinforcing device of uniform quality with reliable stress transmission and a large reinforcing effect can be produced at a low cost in a factory.

(5) Compared to conventional open reinforcing steel plates for steel-framed reinforced concrete structures, workability is improved due to the cylindrical member and rod-shaped protrusions, and the weight is reduced because the dimensions of the steel plate members are not constrained by the steel frame arrangement. In particular, if parts unnecessary for strength are removed, further weight reduction can be achieved.

(6) For a structure having an electromagnetic wave shielding effect, it is possible to easily provide an opening reinforcing device that maintains the effect.

[Brief explanation of drawings]

FIG. 1 is a plan view of one embodiment of the present invention, FIG. 2 (1) is a sectional view taken along line 1--2 in FIG. 1, and FIGS. 3 and 4 are plan views of other embodiments. ...Opening reinforcement device, 2...Cylinder member, 3...
Steel plate member, 4... Rod-shaped projection, C... Center axis line. Patent Applicant Kajima Corporation Patent Application Agent Patent Attorney Ichitorei Tsugube Figure 1 Figure 1 Figure 2 Figure 3 Association Figure 4

Claims (1)

[Claims] (1) A hollow steel cylindrical member, a steel plate member integrally connected to the outer surface of the peripheral wall of the cylindrical member, and a rod-shaped projection protruding from the periphery of the steel plate member. A device for reinforcing openings in concrete structures. (2. The opening reinforcing device as set forth in claim 1, characterized in that unnecessary portions of the steel plate member in terms of strength are removed. (3) The opening reinforcing device as set forth in claim 1. In the reinforcing device, the opening reinforcing device is characterized in that the cylinder member, the steel plate member, and the bar-like protrusion are integrally cast. An opening reinforcing device characterized in that a member, a steel plate member, and a rod-shaped projection are integrally welded. (5) In the opening reinforcing device according to claim 1, the cylindrical member has a hollow cylindrical shape. An opening reinforcement device featuring: