JPH0393930A - Structure for increasing adhesion of reinforcement to concrete in rc or src 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 (Field of Industrial Application) The present invention relates to a structure for enhancing the adhesion of reinforcing bars to concrete in RC or SRC structures. (Prior Art) Hitherto, high-strength reinforcing bars such as SD50, SD70, and SDIOO have not been used. Therefore SD30,
Regarding ordinary reinforcing bars such as SD35, the Architectural Institute of Japan's Reinforced Concrete Structural Standards and the Building Standards Act's Construction Association do not provide any specific regulations regarding column-beam joints, other than provisions regarding the anchorage length of beam main reinforcements. There were no problems. (Problem to be solved by the invention) However, when high-strength reinforcing bars are used as in recent years, large stress is generated on the reinforcing bars, which causes the reinforcing bars to lose their adhesion to concrete and cause them to slip. This causes adhesive failure and shear failure in the bunnel zone to occur easily and pull out from the surrounding concrete, and there are severe restrictions on the attachment of beam reinforcement to the center column at the column-beam joint. , subject to constraints on beam reinforcing bar diameter.

In addition, when high-strength reinforcing bars are used in this way, large stresses are generated in the reinforcing bars as described above, and in column and beam members, adhesion of the reinforcing bars to concrete becomes a problem, making it easy for members to fail due to adhesion. The present invention was proposed in view of the above circumstances, and its purpose is to strengthen the adhesive force to concrete, prevent adhesive failure and shear failure against large forces, and protect structures. The object of the present invention is to provide a structure that enhances the adhesion of reinforcing bars to concrete in an RC or SRC structure that can ensure toughness.

(Means for Solving the Problem) In order to achieve the above object, the RC or S according to the present invention
A structure for enhancing the adhesion of reinforcing bars to concrete in RC structures is constructed by attaching anchoring hardware to the beam reinforcing bars and/or column reinforcing bars in the panel zone of beam columns in the threaded reinforcing bars of RC or SRC horizontal structures. The invention of claim 2 provides beam reinforcing bars and/or beam reinforcement at each end of the beam column.
Alternatively, anchoring hardware is attached to column reinforcing bars.

Furthermore, the invention according to claim 3 is such that a plate and a fixing metal are attached to the beam reinforcing bars and/or the column reinforcing bars at each end of the beam column.

(Function) As described above, in the present invention, by attaching the anchoring hardware to the beam reinforcing bars and/or column reinforcing bars in the panel zone consisting of beams and columns, the adhesion force of the reinforcing bars to concrete increases, and the large size of the anchoring hardware increases. This action increases the anchoring force of the reinforcing bars to the concrete. Therefore, the reinforcing bars are prevented from slipping out, shear failure in the panel zone is prevented, the rigidity and ultimate strength of the column-beam joint are both increased, and stress transmission between members is completely achieved during large deformations.

The invention as claimed in claim 2 enhances the adhesion of the reinforcing bars to concrete by using anchoring hardware attached to the ends of column reinforcing bars and/or beam reinforcing bars, and prevents adhesion failure of column and beam members by the large size of the anchoring hardware. This is to prevent In addition, the rigidity and ultimate strength of each member are increased, and stress transmission between members during large deformations is completely achieved.

According to the third aspect of the present invention, a plate is attached to the beam reinforcing bars and/or column reinforcing bars at each end of the beam column in addition to fixing metal fittings, thereby preventing adhesion failure of the column and beam members and preventing the members from being severely deformed. This ensures that stress transfer between the two parts is completely achieved.

(Example) The present invention will be explained below with reference to the illustrated example. In the example shown in FIG. 1, (A) is a column of RC structure, (B) is a beam, and in the panel zone consisting of the column and beam, column reinforcement (1) and beam reinforcement ( Nuts (3), each of which constitutes a plurality of the fixing hardware, are installed in a distributed manner on 2).

In the figure, (4) is the hoop muscle, and (5) is the stirrup muscle. Since the illustrated embodiment is constructed as described above,
The nuts (3) attached to the column reinforcing bars (1) and beam reinforcing bars (2) in the panel zone increase the adhesion of the reinforcing bars to concrete, and the nuts (3)
Due to the large size effect, the column reinforcing bars (1) and beam reinforcing bars (2) are prevented from slipping out from the panel zone.

Therefore, shear failure in the panel zone is prevented, the cross section of the member can be reduced, and the selection of the column width is not restricted by the adhesion force of the reinforcing bars passing through the beam. In addition, the rigidity and ultimate strength of the column-beam joints are both increased, and stress transmission between members during large deformations is completely achieved.

Note that the nut (3) may be attached only to the column reinforcing bar (1) or only to the beam reinforcing bar (2), if necessary.
In the embodiment shown in Fig. 2, a plurality of nuts (3) are distributed and attached to the column head and column base portions of the column reinforcing bars (1), which are connected to the threaded reinforcing bars. Multiple nuts (3) are distributed and attached to the end of the reinforced beam reinforcing bar (2). According to the embodiment, the increase in the adhesion force of the column and beam reinforcing bars (1), (2)' to the concrete by the nut (3) and the large action of the nut (3) result in the increase in the strength of each of the reinforcing bars (1) and (2). Breaking out of the concrete is prevented, adhesion failure of the column (A) and beam (B) members is prevented, the rigidity and ultimate strength of each member are increased, and stress transmission between members during large deformations is completely achieved. It will be done.

Figure 3 shows an RC consisting of columns (a) and beams 6) as shown in Figure 4.
The load-deformation curve shows the relationship between the deformation δ and the load Q when a load Q is applied to a structural specimen.The solid line shows the case without the nut (3), and the dotted line shows the nut (3) attached to the column and beam reinforcement. It is shown that the toughness of the structure was improved by the example of the present invention.

Note that the nut (3) is attached only to the column reinforcing bar (1) or only to the girth reinforcing bar (2) as necessary.

In the figure, parts equivalent to those of the above embodiment are given the same reference numerals.

In the embodiment shown in FIG.
6) and fasten them with nuts (3)' (see Figure 6). Each of the reinforcing bars (
1) Due to the increase in adhesion to concrete in (2) and the large action of play (6), each of the reinforcing bars (1) (
2) is prevented from coming off, adhesion failure is prevented, and toughness is improved.

Figures 7, 8, and 9 show when the plate (6) is placed at the end of the test piece (C), and when the plate (6) is placed at the end of the test piece (C), respectively.
Fig. 10 shows the fracture state when the plate (6) is placed in the center of the test piece (C) and when the plate (6) is not placed on the test piece (C). (
C), Fig. 11 shows each test device for the test specimen with the plate (6) arranged in the center, and Fig. 12 shows the load-deformation curve of each of the test specimens and the test specimen without the plate (6) as a control example. shows.

Note that, if necessary, the plate (6) may be attached only to the column reinforcing bars (1) or only to the beam reinforcing bars (2).

In the drawings, parts equivalent to those of the above embodiments are given the same reference numerals.

(Effects of the Invention) As described above, the present invention, in a solid reinforcement of an RC or SRC structure, attaches fixing hardware to the beam reinforcement and/or column reinforcement in a panel zone consisting of beams and columns to integrate them with concrete, This system aims to transmit stress between the concrete and the reinforcing bars, prevent shear failure in the panel zone, reduce the cross section of the member, and improve toughness.

According to the invention of claim 2, by attaching fixing hardware to the beam reinforcing bars and/or column reinforcing bars at each end of the beam column, it is possible to prevent adhesion failure of the column and beam members and improve toughness. .

According to the third aspect of the present invention, plates and fixing hardware are attached to the girdle reinforcing bars and/or column reinforcing bars at each end of the beam and column to prevent adhesion failure of the beam and column members and improve toughness. This increases the shear strength of the column capital, column base, and beam end.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a structure for increasing the adhesion of reinforcing bars to concrete in an RC or SRC structure according to the present invention, and FIG. 2 is a longitudinal cross-sectional view showing another embodiment of the present invention. Fig. 3 is a load-deformation relation diagram showing the test results, Fig. 4 is a front view showing the test specimen and test method, Fig. 5 is a longitudinal sectional view showing still another embodiment of the present invention, Fig. 6 is a perspective view showing the plate attachment part, FIGS. 7, 8, and 9 are explanatory diagrams showing the failure status of various test specimens, and FIGS. 10 and 11 show the test specimens and test methods, respectively. Explanatory diagram,
FIG. 12 is a relationship diagram of load and deformation showing the test results. (A)...Column, (B)...Beam, (1)...
...Column reinforcing bars, (2)...Beam reinforcing bars, (3)...
・Nut, (6)...Plate.

Claims (3)

[Claims] (1) In threaded reinforcing bars of RC or SRC structure,
Enhancing the adhesion of reinforcing bars to concrete in an RC or SRC structure, characterized in that fixing hardware is attached to beam reinforcing bars and/or column reinforcing bars in a panel zone consisting of beams and columns, and the fixing hardware is integrated with concrete. Law. (2) RC or SRC characterized in that fixing hardware is attached to the beam reinforcing bars and/or column reinforcing bars at each end of the beam column.
A structure that enhances the adhesion of reinforcing steel to concrete in structures. (3) A structure for enhancing adhesion of reinforcing bars to concrete in an RC or SRC structure according to claim 2, wherein plates and fixing hardware are attached to beam reinforcing bars and/or column reinforcing bars at each end of the beam column.