JPH09151613A - Reinforcement structure for existing concrete columnar body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability performance and fire resisting performance as working ability without increasing the dead weight of a concrete columnar body more than it is required. SOLUTION: The reinforcement structure for existing concrete columnar body has a plurality of shear reinforcements 13 consisting of linear bodies 13 wound around an existing concrete columnar body 11 at fixed intervals; a net-shaped body 14 provided so as to wrap the existing concrete column 11 on the shear-reinforcements 13; and mortar 15 sprayed toward the concrete column 11 from the upper sides of the shear reinforcements 13 and the net- shaped body 14. Tension force may be introduced into the linear body 13, or a mortar thickness indicating jig having a thickness guide to prescribe the fixed sprayed thickness of the mortar 15 may be provided between the shear reinforcements 13 and the existing concrete column.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reinforcing structure for an existing concrete columnar body.

[0002]

2. Description of the Related Art There are the following conventional examples of reinforcing structures for existing concrete pillars, that is, existing concrete pillars such as bridge piers and buildings. Steel plate reinforced structure: A steel plate is wrapped around the circumference of a concrete column,
It is formed by filling non-shrink mortar between the steel plate and the concrete column. RC reinforced structure: A main reinforcement and a shear reinforcement are provided on the outer periphery of a concrete column, a form is installed on the outer periphery, concrete is placed in the form, and the form is removed after the concrete is hardened. Fiber-reinforced structure: A reinforcing fiber such as carbon fiber is attached to the outer periphery of a concrete column to form it.

[0003]

However, in the above-mentioned conventional steel plate reinforcing structure, since the weight of the steel plate is large, there is a problem that a lifting machine or the like is required and the work efficiency is low. Further, in the RC reinforced structure, the weight of the concrete column is increased due to the added concrete, so that the load weight of the foundation may become larger than the allowable value. Further, the fiber-reinforced structure has a problem that the durability performance and fire resistance performance of the reinforcing fiber for a long period of time are not sufficiently high.

The present invention has been made in order to solve the above problems, and its purpose is to provide good workability, durability of a concrete columnar body without unnecessarily increasing, and durability and fire resistance. It is to provide a reinforcing structure for an existing concrete columnar body having excellent performance.

[0005]

The present invention has been made in view of the above-mentioned object, and its gist is to provide a plurality of shear reinforcing bars composed of linear bodies wound at a predetermined interval on an existing concrete columnar body. , A reinforcing structure for an existing concrete columnar body, which comprises a mesh body provided so as to wind an existing concrete column above these shear reinforcing bars, and a mortar sprayed onto the existing concrete column from above these shear reinforcing bars and mesh bodies It is in.

Here, the above-mentioned linear body wound around the existing concrete columnar body at a predetermined interval restrains the fractured concrete to some extent when the concrete is ruptured by an external force such as an earthquake, so that the deformability of the concrete columnar body is improved. Any material that can be improved can be used, and for example, a reinforcing rod, a steel wire, a rope made of carbon fiber, and a rope formed by twisting steel wire and carbon fiber can be used.

Further, the rebar spacing of the shear reinforcing bar can be appropriately determined. For example, it is also possible to arrange the bars with a narrower interval at locations where a large moment acts, and on the other hand, to arrange the bars at relatively large intervals at a location with a small moment.

Further, the reticulate body may be any one as long as it can improve the adhesion of the sprayed mortar to the existing concrete columnar body. For example, a wire net, a net made of carbon fiber, a lath or a plastic net is used. it can.

In the existing concrete columnar reinforcing structure of the present invention, a tension force may be introduced into a plurality of shear reinforcing bars wound at a predetermined interval on the existing concrete columnar body, thereby increasing the restraining force for concrete, It is possible to enjoy the advantage of improving the deformation performance against an earthquake or the like.

In the reinforced structure of an existing concrete columnar body of the present invention, a mortar thickness indicator provided with a thickness guide for defining a predetermined spraying thickness of the mortar between the shear reinforcing bar and the existing concrete column. You may provide a tool. Here, the mortar thickness indicating jig can be formed by a long member and a plurality of protruding pieces (thickness guides) provided so as to be orthogonal to the axial direction thereof. As the long member, for example, a long member formed of a flat steel, an angle steel material, a steel rod, or a resin material other than steel in the same shape as these steel materials may be used. Further, the protruding piece may be designed to indicate the surface position of the sprayed mortar at any position such as the tip portion or the intermediate portion, and when it is specified at the intermediate portion of the protruding piece, it is projected from the mortar surface after spraying the mortar. Only the part is removed and the remaining part is sprayed and embedded in the mortar.On the other hand, when instructing with the tip of the protruding piece, place it at the same height as the tip of the protruding piece or at a position slightly higher than the tip of the protruding piece. Form the surface of the spray mortar and embed all the protruding pieces in the spray mortar.

In addition to the above-described structure, the mortar thickness indicating jig has a long member, a supporting member provided so as to be orthogonal to the axial direction thereof, and a surface position of the sprayed mortar supported by the tip of the supporting member. It may also be formed with a surface indicating member (thickness guide) for indicating.

In the existing concrete columnar reinforcing structure of the present invention, a reinforcing bar arrangement guide for defining the arrangement of the shear reinforcing bar is formed in the mortar thickness indicating jig, and the reinforcing bar arrangement guide and the thickness guide are provided. Mix in the same jig,
Thereby, the reinforcing bar arrangement instruction jig and the mortar thickness instruction jig may be used together.

In the reinforcing structure of the existing concrete columnar body of the present invention, a plurality of shear reinforcing bars, a mortar thickness indicating jig, and a mesh body are preassembled to form a reinforcing material assembly having a predetermined size. It is also possible to install a plurality of assemblies on the existing concrete pillars and connect them. At this time, a single shear reinforcing bar that winds the concrete columnar body is formed in a shape that is divided into two or more parts, and the mortar thickness indicating jig is a long member and a plurality of parts that are projected from this. The reinforcing material assembly is formed by fixing the divided shear reinforcing bars to the mortar thickness indicating jig at a predetermined interval by fixing the mesh body on the outer periphery of the fixed shear reinforcing bars. can do. When connecting such reinforcing material assemblies, the ends of the split shear reinforcements are joined together in a conventional manner, i.e., the ends are wrapped and welded, or the ends are placed in a coupler. To fill in with adhesive or to drive a wedge into the coupler.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a reinforcing structure for an existing concrete columnar body of the present invention. In FIG. 1, in the reinforcing structure, a plurality of reinforcing bars as shear reinforcing bars 13 are wound around an existing concrete column 11, a wire net 14 is fixed onto the shear reinforcing bars 13, and the shear reinforcing bars 13 and 14 are embedded. Thus, the sprayed mortar 15 is sprayed on the existing concrete column to form the sprayed mortar 15.

The shear reinforcing bars 13 are arranged with a narrow gap in the portion of the existing concrete column 11 where a large moment acts, and are arranged in a relatively large gap in a portion where the acting moment is small. For example, in the upper and lower ends of the pier (not shown), more shear reinforcement bars 1 are provided at narrow intervals.
3 are arranged, and the bars are arranged in the middle part at relatively large intervals. Further, by introducing a tension force into the shear reinforcing bar 13, it is possible to strengthen the restraining force with respect to the existing concrete column.

The spray mortar 15 is made of a spray mortar material (trade name: Shot Patch II) disclosed in Japanese Patent Application No. 7-48263 of the applicant of the present application, and a shear reinforcing bar 13 and a wire net 14 are embedded therein. Spray it to a thickness of about 10 mm. For example, when the shear reinforcement bar 13 with a diameter of about 13 mm is wound around a concrete column with a cross-sectional dimension of about 90 × 90 cm, the spray mortar 15 is 40 mm from the surface of the concrete column.
Spray up to a certain thickness.

The above reinforcing structure may be provided with a mortar thickness indicating jig 12 as shown in FIG. 2 in order to control the sprayed mortar to a predetermined thickness during construction. That is, the mortar thickness indicating jig 12 includes an angle steel material 12b and a plurality of projecting pieces 12a projecting from the top of the angle steel material 12b at predetermined intervals, and the projecting pieces 12a are the angle steel material 12b.
It is fixed so as to be at the same angle with respect to the two sides, and the length is formed so that the tip is positioned at the surface height of the spray mortar 15 or slightly lower than the surface height. In addition, the protruding piece 12a
Are provided at the same intervals as the reinforcing bar 13 of the shear reinforcing bar 13, the shear reinforcing bar can be arranged by using the protruding piece 12a as a mark, and the work efficiency is improved.

Such a mortar thickness indicating jig 12 is shown in FIG.
And as shown in FIG. 4, the angle steel material 12b is arrange | positioned in contact with the four corners of the existing concrete pillar 11, and each shear reinforcement bar 13 passes above or below the protrusion piece 12a, and the mortar thickness instruction | indication jig 12 is shown. From the top of the existing concrete pillar 11
The reinforcing structure of the present invention can be formed by winding the mortar 15 onto the shear reinforcing bar 13, fixing the wire net 14 on the shear reinforcing bar 13, and spraying the sprayed mortar 15 to a predetermined thickness with the protruding piece 12a as a mark.

In the present invention, the mortar thickness indicating jig 12, the shear reinforcing bar 13 and the wire net 14 may be preassembled as the reinforcing material assembly 20 as shown in FIG. That is, the shear reinforcing bar 14a is formed in a U shape, and each mortar thickness indicating jig 12 is brought into contact with the inside of the two corners of the shear reinforcing bar 14a so that a binding wire (not shown) is formed.
Then, the reinforcing material assembly 20 is formed by fixing it to the projecting piece 12a and fixing the wire netting 14 to the outside of the shear reinforcing bar 14a.

And, such a reinforcing material assembly 20 is
A pair of symmetrically formed shear reinforcement bars 14
The a is abutted on the existing concrete column and the tips are arranged so as to overlap each other, and the tips are fixed by welding. After welding the shear reinforcing bar 14a, the wire mesh 14 at the joint is fixed to the shear reinforcing bar 14a, and the spray mortar 15 is sprayed in the same manner as described above, whereby the reinforcing structure of the present invention is completed.

FIG. 6 shows a graph obtained by calculation in order to compare the deformation performances of the existing concrete columns provided with the reinforcing structure of the present invention and other existing concrete columns. "Unreinforced" shown by the alternate long and short dash line in Fig. 6 means a cross-sectional size of 800 x 800 mm, a main bar ratio of 2.48% and a stirrup ratio of 0.05
% Of the existing concrete columns without any reinforcing structure. The "rolled steel plate" shown by the dotted line means that a clearance of 50 mm is secured around the existing "non-reinforced" concrete column, and the thickness is 6 mm.
It means a conventional steel plate reinforcing structure for an existing concrete column, which is formed by winding the steel plate in (1) and filling the clearance with non-shrink mortar. Furthermore, the "reinforcement structure of the present application" means that reinforcing bars having a diameter of 16 mm are wound around the existing "non-reinforced" concrete columns at intervals of 100 mm, and a diameter of 5 mm is placed on the reinforcing bars.
It means a reinforcing structure of an existing concrete column of the present invention by fixing a wire net formed in a 50 mm mesh with the steel wire of No. 3, and spraying a mortar having a thickness of 40 mm. From the graph of FIG. 6 obtained under the above conditions, it can be seen that the “reinforcement structure of the present application” has substantially the same deformability as that of “rolled steel plate” and about 4.1 times that of “non-reinforced”.

Next, an embodiment different from those of FIGS. 1 to 5 will be described with reference to FIGS. 7 to 13. FIG. 7 is a front view showing a reinforcing structure of an existing concrete columnar body of the present invention,
8 is a sectional view taken along line VIII-VIII in FIG. 7, FIG. 9 is a sectional view of a circle IX portion in the reinforcing structure shown in FIG. 7, and FIG. 10 is a member used as a mortar thickness indicating jig. 11 (a) is a side view showing the circle X in FIG.
It is a cross-sectional view showing a mortar thickness indicating jig in a portion,
FIG. 11B is a sectional view showing the reinforcing bar arrangement guide in the circle X portion of FIG.

In the reinforcing structure shown in FIG. 7, chamfered portions 11 'are formed at the four corners of an existing rectangular concrete column 11, and mortar thickness indicating jigs 22 are arranged on the chamfered portions 11'. From above, the shear reinforcing bar 23 is wound around the existing concrete column 11, and further, the wire netting 14 and the spray mortar 15 are provided in the same manner as the reinforcing structure of FIG.

By forming the chamfered portion 11 'as described above, there is an advantage that the gap between the shear reinforcing bar 23 and the surface of the rectangular concrete column 11 can be reduced. That is, when the shear reinforcing bar 23 is bent to be wound around the rectangular concrete column 11, the bent portion is formed in a shape having a certain curvature or more and cannot be formed at a right angle.
When this bent portion is brought into contact with the four corners of the rectangular concrete column 11 at right angles, a gap is created between the bent portion and the surface of the rectangular concrete column 11, and the mortar thickness indicating jig 2 is provided at the four corners of the right angle.
When 2 is provided, this gap is enlarged. However,
In the present invention, the chamfered portion 11 'is formed according to the curvature of the bent portion of the shear reinforcing bar 23, and the mortar thickness indicating jig 22 is provided on the chamfered portion 11'. The thickness of the tool 22 is absorbed by the chamfered portion 11 ′, and the shear reinforcing bar 23 and the rectangular concrete pillar 11 are absorbed.
The gap with the surface of is reduced.

The mortar thickness indicating jig 22 is shown in FIG.
As shown in (a), a plurality of bolts 25a and a plurality of round steel as the bar arrangement guide 28 are provided on one surface of the flat bar 24 (see FIG. 10) protruding at predetermined intervals, and the plurality of bolts 25a are provided. A channel material 25d (see FIG. 12) in which a hole (not shown) to be penetrated is formed in one flange, and a surface indicator 26 as a thickness guide that is attached to the other flange of the channel material 25d, Fixing nuts 25b and 25c for fixing the channel material 25d to the plurality of bolts 25a
And

In such a mortar thickness indicating jig 22, a hole (not shown) is formed in the flat steel 24, and an anchor bolt (not shown) is passed through the hole to make the mortar thickness indicating jig 22. 22 is fixed to the chamfer 11 '. Further, the length of the flat steel 24 is formed slightly shorter than the length of the pillar to be reinforced, so that the flat steel 24 does not come into contact with the upper and lower ends of the pillar, that is, a non-reinforced area of about 2 to 5 cm. Form. Further, the channel material 25d and the surface indicating material 26
The length of is approximately the same as that of the flat steel 24. Furthermore,
The surface indicator 26 is made of an elastic material such as rubber,
It is formed using plastic or foam.

The shear reinforcing bar 23 has a pair of shapes such that the opposite ends 11a and 11b of the rectangular concrete column 11 can be connected by abutting each other, that is, the shape as shown in FIG. The shear reinforcing bars 23a and 23b may be formed, or a pair of shear reinforcing bars (not shown) may be formed in the same "U" shape. The shear reinforcing bars 23a and 23b having such a shape are arranged on the bar arrangement guide 28 projecting from the mortar thickness indicating jig 22.
Temporarily place it on top of each other and put the ends together to make a coupler 2.
7 and connect to the bar arrangement guide 28 with a binding wire or the like. Further, as shown in FIG. 7, the shear reinforcing bars 23 are arranged at narrow intervals in the upper and lower end sections of the column 11 where a large moment acts, and are arranged at relatively large intervals in an intermediate section where a small moment acts. .

Further, an epoxy resin or high-strength non-shrink mortar is injected into the coupler 27 connecting the abutted ends. Such shear reinforcements 23a, 2
The coupler 27 connecting the 3b may be arranged such that, for example, as shown in the lower end section of FIG. 7, the couplers 27 of the shear reinforcing bars that are vertically adjacent to each other are staggered in the same facing surface, or As shown in the upper end section of FIG. 7, the couplers 27 of the shear reinforcing bars that are vertically adjacent to each other may be arranged on different facing surfaces.

Next, a construction procedure in the embodiment shown in FIGS. 7 to 13 will be described. First, the surface treatment of the existing concrete pillar 11 is performed. In this step, dirt or the like that adversely affects the adhesion of the spray mortar 15 is removed with a sander or a wire brush, and the four corners of the existing concrete pillar 11 are scraped off to form a chamfered portion 11 '.

Next, the flat steel plate 24 of the member shown in FIG. 10 is brought into contact with the chamfered portion 11 ', and this is fixed by an anchor bolt (not shown). And the shear reinforcement bars 23, 2
3a and 23b are temporarily placed on the bar arrangement guide 23, the ends thereof are butted against each other and the coupler 27 is fitted, and the shear reinforcing bars 23, 23a and 23b are connected to the bar arrangement guide 23 by a binding wire (not shown). Then, the coupler 27 is filled with epoxy resin.

A predetermined number of shear reinforcement bars 23, 23a, 23b
After arranging, the mounting process of the surface indicator 26 as a thickness guide is performed. In this step, first, a fixing nut 25b is screwed into each of a plurality of bolts 25a protruding from the flat steel 24, then a hole formed in one flange of the channel member 25d is inserted into the bolt 25a, and The fixing nut 25b is screwed to fix the channel member 25d, and finally, the surface indicator 26 is attached to the remaining flange of the channel member 25d.

After the step of attaching the surface indicating material 26, a base material (sealer) for preventing the existing concrete pillars 11 from absorbing the water content of the spray mortar 15 is applied to the surface of the existing concrete pillars 11, and then, The spraying of the spraying mortar 15 is performed in two layers. The spray mortar 15 of the first layer is sprayed to a thickness such that the shear reinforcing bars 23, 23a, 23b can cover it, and then the wire net 14 or the synthetic resin net is attached on the first layer.
The spraying mortar 15 of the second layer is sprayed from above the wire netting 14 or the synthetic resin net while the height of the surface indicator 26 is used as a mark, and the surface thereof is leveled with a metal iron or the like.

The day after the spraying mortar 15 was constructed, as shown in FIG.
As shown in FIG.
By peeling it off from the surface of the sprayed mortar 15 and filling the concave portion on the surface of the sprayed mortar 15 with the mortar, the reinforcing structure of the existing concrete columnar body of the present invention is completed. Here, the surface indicator 26 is removed from the surface of the sprayed mortar 15, but the reinforcing structure of the present invention is
The present invention is not limited to this, and for example, a surface treatment material such as mortar may be applied onto the surface indicator material 26 so that water does not penetrate to the channel material 25d while the surface indicator material 26 is buried in the spray mortar 15. Is also good.

[0034]

According to the present invention, since a plurality of shear reinforcing bars are wound around an existing concrete columnar body, a mesh body is fixed on the shear reinforcing bars, and then sprayed mortar is sprayed to form a reinforcing structure. The reinforcement material is lighter and easier to handle than the reinforcement structure using the steel plate. Further, the sprayed mortar covering the shear reinforcement bars improves durability and fire resistance, and the net-like body improves the adhesion of the sprayed mortar to the columnar bodies.

Further, in the present invention, since the shear reinforcing bar improves the structural yield strength and the mortar is sprayed only to a thickness that can cover the shear reinforcing bar, the weight of the reinforcing structure itself can be reduced. This is possible, and it is possible to prevent the problem that the weight of the concrete columnar body increases and the load on the foundation becomes too large as in the conventional RC reinforcing structure.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a reinforcing structure for an existing concrete columnar body of the present invention.

FIG. 2 is a perspective view showing a mortar thickness indicating jig.

FIG. 3 is a perspective view showing a state in which a mortar thickness indicating jig and a shear reinforcing bar are installed on an existing concrete columnar body.

FIG. 4 is a cross-sectional view when a mortar thickness indicating jig is added to the existing concrete columnar reinforcing structure of the present invention.

FIG. 5 is a perspective view of a reinforcing material assembly used in a reinforcing structure for an existing concrete columnar body of the present invention.

FIG. 6 is a graph comparing the existing concrete columnar reinforcing structure of the present invention with a conventional example in terms of deformation performance.

FIG. 7 is a front view showing a reinforcing structure for an existing concrete columnar body of the present invention, which is different from FIG.

8 is a cross-sectional view taken along the line VIII-VIII in the reinforcing structure shown in FIG.

9 is a sectional view of a circle IX portion in the reinforcing structure shown in FIG.

FIG. 10 is a side view of members constituting a mortar thickness indicating jig.

11A is a cross-sectional view showing a mortar thickness indicating jig in a circle X part of FIG. 8, and FIG. 11B is a cross-sectional view showing a reinforcing bar arrangement guide in the circle X part of FIG.

FIG. 12 is a perspective view of one member constituting a mortar thickness indicating jig.

FIG. 13 is an explanatory sectional view showing a construction procedure of the mortar thickness indicating jig of FIG. 11 (a).

[Explanation of symbols]

 11 Existing Concrete Column 12 Mortar Thickness Indicating Tool 12a Projecting Piece (Thickness Guide) 13,23 Shear Reinforcing Bar (Linear Body, Shear Reinforcing Bar) 14 Wire Mesh (Reticulated Body) 15 Spray Mortar 24 Reinforcing Bar Arrangement Guide 26 Surface Indicator member (thickness guide)

Claims (4)

[Claims] 1. A plurality of shear reinforcing bars consisting of linear bodies wound at a predetermined interval on an existing concrete columnar body, a mesh body provided so as to wind an existing concrete column on the shear reinforcing bars, and these shearing bars. Reinforcement structure of an existing concrete columnar body comprising reinforced mortar and mortar sprayed on the existing concrete column from above. 2. The reinforcing structure for an existing concrete columnar body according to claim 1, wherein a tension force is introduced into the linear body. 3. A mortar thickness indicating jig having a thickness guide that defines a predetermined spraying thickness of the mortar is provided between the shear reinforcing bar and the existing concrete column. Reinforcement structure of existing concrete columns. 4. The reinforcing structure for an existing concrete columnar body according to claim 3, wherein a reinforcing bar arrangement guide that defines the arrangement of the shear reinforcing bar is formed in the mortar thickness indicating jig.