JPH10237825A - Method of reinforcing concrete structure and reinforcing bar fixing jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constrain swelling of parallel opposed surfaces of a skeleton by engagingly locking a reinforcing bar arranged on the outer surface of the skeleton to a constraining bar inserted to a through-hole, engagingly fixing a hook on the reinforcing bar, and connecting a plurality of the hooks to both ends of a through-bolt substituted for a constraining bar. SOLUTION: In a construction method of reinforcing a concrete structure 1 having an oval sectional skeleton by constructing a concrete for reinforcing 3 on an existing skeleton concrete 2 to extend the section, a through-hole 5 is bored between opposed parallel surfaces, a through-bolt 12 is inserted thereto, and reinforcing bar engaging fixing jigs 11 are screwed and constrained to both the ends thereof on the existing wall body outer surface. The reinforcing bar fixing jig 11 has two fixing arms having hooks on the tips, and a reinforcing bar 4 is engagingly fixed to the hooks. Thus, the number of through-holes to be bored in the concrete structure can be minimized, a constraining bar is dispensed with, and the hook having the reinforcing bar fixed thereto by a bolt can be firmly fixed to the skeleton outer surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing an existing structure having two substantially parallel opposed surfaces, for example, an existing concrete structure such as a bridge pier having a rectangular or oval cross section and its use. The present invention relates to a reinforcing bar fastening jig.

[0002]

2. Description of the Related Art Reinforcement for improving the earthquake resistance of existing bridges such as piers is required. As such a reinforcing method, a steel plate or a precast concrete panel is attached around a columnar skeleton such as a bridge pier, and concrete is filled between the skeleton and the reinforcement, or a reinforcing bar is arranged on the outer surface of the skeleton to increase the concrete. There is a method of hitting. In this case, when the columnar section is circular, the reinforcing structure works effectively.However, in the case of a columnar body having a rectangular or oval cross section, the protrusion of the parallel facing surface must be restricted. An effective reinforcing structure is not obtained, and it is necessary to form a horizontal hole penetrating the frame, insert a restraining bar, hook both ends of the bar, and attach the reinforcing bar.

As a method of arranging the restraining muscles, a method of forming a through-slit by a water jet in a skeleton and arranging the same is also proposed in Nikkei Construction in 1995 (November 10, 1995), and is provided at an arbitrary position. Although there is an advantage that a slit can be provided, there is a problem that the cost of forming the slit is enormous. On the other hand, although the freedom of arrangement is slightly lost, through-holes are drilled in the existing concrete skeleton by horizontal boring with a concrete drill, and as described above, penetrating through the through-holes and penetrating restraint bars, In general, a technique of restraining the reinforcing bars to prevent the overflow of the overcast concrete is prevented. However, this method also requires
There is a problem in that the number of the through-holes increases, and the time and effort for forming an effective hook at the end of the inserted reinforcing bar require a large cost.

[0004] As one means for solving this problem, there is a method in which several reinforcing bars are collectively held by a rigid steel frame or the like. However, a thick concrete cover required for embedding the holding steel frame is required. However, the thickness of the thickened concrete increases, which is uneconomical.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a technique for restraining protrusion of parallel opposing surfaces of a skeleton of a concrete structure having an existing rectangular or oval cross section, and a through hole for a restraining muscle. Method that reduces the number of drilling holes, does not require hooking of the end of the restraining bar, and can secure the reinforcing effect by the minimum required concrete cover thickness and the reinforcing bar used for it The purpose is to develop jigs.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been developed to achieve the above-mentioned object. The present invention is directed to a method in which a hole penetrating a skeleton is formed in an existing concrete structure, and a reinforcing bar disposed on the outer surface of the skeleton is provided. In a reinforcing method in which concrete is added to a surface layer portion of a skeleton by being locked to a restraining bar inserted into a through hole, hooks are engaged with the reinforcing bar, and a plurality of hooks are attached to both ends of a through bolt replacing the restraining bar. A method for reinforcing a concrete structure characterized by joining. ADVANTAGE OF THE INVENTION According to this invention, while the number of the through holes drilled in the concrete structure can be significantly reduced, the formation of the hooks of the restraining bars is unnecessary, and the hooks with the reinforcing bars fastened to the outer surfaces of the skeleton by the bolts are strong. Can be established. In this case, a normal steel bolt may be used as the bolt. In particular, when a PC steel rod is used, the bolt can be strongly coupled with a small number of bolts, and a small-diameter through hole is used. It is efficient because it is sufficient to pierce.

[0007] As a jig which can be suitably used for carrying out the above-mentioned method, there are provided a supporting plate having a bolt through hole which is in contact with an outer surface of a skeleton of an existing concrete structure, and a plurality of fixing members which are fixed to the supporting plate and engage reinforcing bars. Consisting of a hook and
It is preferable to use a jig for fastening a reinforcing bar of a concrete structure.
This reinforcing bar fixing jig can securely connect the reinforcing bars, hold the reinforcing bars at a certain position from the surface of the structure to be reinforced, and secure a constant covering in the reinforced concrete. There is also an effect that it is possible to do this reliably.

The reinforcing bars referred to in the present invention are horizontal bars (loop bars) that surround the structure and are arranged horizontally.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a concrete structure 1 having an oval shaped skeleton. A method of constructing an extra-strength concrete 3 on an existing skeleton concrete 2, enlarging a cross section, piercing a through-hole 5 between opposing parallel surfaces, inserting a through-bolt 12, and attaching and reinforcing reinforcing bars to both ends. The tool 11 is screwed and restrained on the outer surface of the existing wall. As shown in FIG. 4, the reinforcing bar fastening jig 11 has two fastening arms 15 each having a hook 16 at the tip, and the reinforcing bar 4 is fastened to the hook 16.

FIG. 2 is a view (front view) taken along the line AA of FIG.
This shows a state in which two reinforcing bars 4 are fixed by one reinforcing bar fixing jig 11. FIG. 3 is a view (side view) taken on line BB of FIG. 1. Bolt 12 inserted in through hole 5
Has a reinforcing bar fastening jig 11 connected to both ends thereof. FIG. 4 is a perspective view of the reinforcing bar fastening jig 11 of the embodiment. A hook plate (an engaging arm) 15 for locking the reinforcing bar 4 is integrally formed with a supporting plate 13 having a bolt through hole 14. Is formed. This integral formation may be performed, for example, by welding. FIG. 5 is a front view of the reinforcing bar fastening jig 11. The bolt 12 is screwed with a nut 18 via a washer 17. The tightening force of the nut at this time may be such that the bolt nut is tightened with an impact wrench or the like so as to apply several tons of tension to the bolt so that the support plate 13 is pressed against the wall surface of the existing structure.

FIG. 6A is a cross-sectional view of a structure according to a conventional locking technique.
A hook is formed at the tip of the bracket, and the reinforcing bar 4 is locked to the hook. FIG. 6B is a cross-sectional view of an example in which the present invention is applied to the same structure, and is a detailed comparative explanatory diagram of the same scale. In the embodiment of FIG. 6B, one through hole 5
The reinforcing bar fastening jig 11 is connected with the bolt 12 inserted through the
As shown in FIG.
This shows that half the number of perforations in the conventional example shown in FIG.

The through bolt 12 of the present invention needs to have a cross-sectional area twice or more that of the conventional restraining bar 21. For example, in the case of a conventional reinforcing bar of 16 mmφ, a 25 mm
φ may be used, and if a PC steel rod is used, it may be about 15 mmφ. Although the present embodiment has been described with reference to an example of reinforcing a concrete structure (pier) having an oval cross section, the present invention can be similarly applied to a structure having a rectangular or square cross section.
Further, in the case of a square cross section, it is effective if the through bolts penetrating between the opposing parallel surfaces are arranged to be orthogonal to each other.

[0013]

According to the method of the present invention, the number of through holes is reduced by half as compared with the conventional method, and labor such as hooking of the end of the restraining muscle is not required. In addition, the reinforcing bar attachment jig also functions as a spacer for reinforcing bars, and the spacing of the reinforcing bars from the existing wall can be precisely arranged. There are ancillary effects such as good.

[Brief description of the drawings]

FIG. 1 is a sectional view of a concrete structure according to an embodiment.

FIG. 2 is a view (front view) taken along the line AA of FIG. 1;

FIG. 3 is a view (side view) taken along arrow BB in FIG. 1;

FIG. 4 is a perspective view of a reinforcing bar fixing jig of the embodiment.

FIG. 5 is a front view of the reinforcing bar fixing jig of the embodiment.

6A is a sectional view of a conventional locking technique, and FIG. 6B is a sectional view of an embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 (Concrete) structure 2 Existing skeleton concrete 3 Upholstered concrete 4 Reinforcing bar 5 Through hole 11 Reinforcing bar fixing jig 12 Through bolt 13 Support plate 14 Bolt insertion hole 15 Hook plate (Mounting arm) 16 Hook 17 Washer 18 Nut 21 Restraint

Claims (3)

[Claims] 1. A hole penetrating a skeleton is formed in an existing concrete structure, and a reinforcing bar disposed on an outer surface of the skeleton is locked to a restraining bar inserted through the through hole, and concrete is added to the surface layer of the skeleton. A method of reinforcing a concrete structure, comprising: hooking a hook to a reinforcing bar, and connecting a plurality of hooks to both ends of a through bolt instead of the restraining bar. 2. The method for reinforcing a concrete structure according to claim 1, wherein the through bolt is a PC steel rod. 3. A concrete structure comprising: a support plate having a bolt through-hole in contact with an outer surface of a skeleton of an existing concrete structure; and a plurality of hooks fixed to the support plate and engaged with reinforcing bars. Jig for fastening reinforcement bars.