JP2002013209A - Method for expanding cotter member and concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cotter member which can give a sufficient earthquake- proof effect to a newly constructed concrete structure. SOLUTION: The cotter member 10 is provided with a fixing section 11 attached to an already existing member and a protruding section 12 which is protruded from the fixing section 11. Both the fixing and protruding sections 11 and 12 are made of fiber reinforced concrete using extra-light-weight concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cotter member used as a shear connector when a new concrete structure is connected to an existing member, and a method for connecting a concrete structure to an existing member to extend the member. Method.

[0002]

2. Description of the Related Art As is well known, when casting cast-in-place concrete to a PC member, a notch called a cotter or the like is provided at regular intervals on the PC member side, and this portion is used as a shear connector. In this way, the joining portions are integrated.

By the way, when connecting a new cast-in-place concrete structure to an existing member in an earthquake-resistant reinforcement of an existing building or the like, a cotter is not provided in advance for the existing member. It is necessary to arrange a member that becomes a shear connector at the joint with the body.

Therefore, in such a case, for example, a cotter member 1 as shown in FIG. 3 is bonded and arranged at a connection target position of a new structure in the existing member 2 to form a shear connector. As shown in FIG. 3, the cotter member 1 includes a fixing unit 3 fixed to the surface of the existing member 2 and a protrusion 4 projecting from the fixing unit 3. By arranging the projections 4, 4,..., Irregularities are formed on the surface of the existing member 2, and the irregularities function as a shear connector.

[0005]

However, since the above-mentioned cotter member 1 is usually formed using concrete, its shear strength may not be sufficient.
In particular, when the new structure is an earthquake-resistant wall or the like, there is a concern that even if such a cotter member 1 is used, a sufficient earthquake-proof effect cannot be expected.

Further, when the cotter member 1 as described above is formed to a predetermined size, its weight becomes very large (for example, about 19 kg), and it is extremely labor intensive to lift and attach it to a predetermined place, and the workability is increased. There was a risk of causing a decrease.

The present invention has been made in view of the above circumstances, and provides a cotter member capable of expecting a sufficient seismic effect to a newly installed concrete structure as compared with the related art. That is the task. Also,
Another object of the present invention is to provide a method for expanding a concrete structure capable of stably connecting a new concrete structure to an existing member with superior workability as compared with the related art. .

[0008]

Means for Solving the Problems To solve the above problems, the present invention employs the following means. That is,
The cotter member according to claim 1, wherein the cotter member is a cotter member that is attached as a shear connector to a position to be joined to the concrete structure in the existing member when the newly added concrete structure is connected to the existing member. And a fixing unit attached to the existing member, and a protrusion that protrudes from the fixing unit.
It is characterized in that both the fixing portion and the protruding portion are formed of fiber reinforced concrete.

[0009] With such a configuration, compared to a case where a cotter member is formed using ordinary concrete,
The shear strength between the fixing portion and the protruding portion can be secured.

[0010] The cotter member according to the second aspect is the first aspect.
2. The cotter member according to claim 1, wherein the fiber reinforced concrete is formed by mixing a fiber material into ultra-lightweight concrete.

[0011] With such a configuration, the cotter member can be made lightweight.

According to a third aspect of the present invention, there is provided a method for expanding a concrete structure by connecting a concrete structure to an existing member and expanding the concrete structure. A cotter member is mounted, and concrete is cast so as to be connected to the cotter member to form the concrete structure. As the cotter member, one formed of fiber-reinforced concrete is used. It is characterized by.

[0013] Because of such a configuration, in the method for adding a concrete structure, a constant shear strength can be expected for the cotter member. You can expect strength.

According to a fourth aspect of the present invention, there is provided a method of extending a concrete structure according to the third aspect, wherein the fiber reinforced concrete is formed by mixing a fiber material into ultra-lightweight concrete. It is characterized by having.

Thus, the weight of the cotter member can be reduced.

According to a fifth aspect of the present invention, there is provided a method of expanding a concrete structure according to the fourth aspect, wherein the concrete structure is provided in an opening surrounded by columns and beams in a building. And the existing members are the columns and beams,
A plurality of cotter members are attached around the opening, and in the opening, a structural material constituting the earthquake-resistant wall is arranged so that a part thereof is located between the cotter members,
The earthquake-resistant wall is formed by placing concrete on the structural material.

With such a configuration, when the earthquake-resistant wall is added, the shear strength of the cotter portion is secured, and a sufficient earthquake-proof effect can be expected. Further, since the weight of the cotter member is reduced, the cotter member can be easily attached especially to the side surface of the column or the lower surface of the beam.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically illustrating an embodiment of the present invention, and reference numeral 10 indicates a cotter member.

The cotter member 10 is made by molding fiber-mixed concrete formed by mixing a fiber material into ultra-lightweight concrete. The cotter member 10 includes a fixing section 11 attached to an existing member and the like, And a protruding portion 12 protruding from the portion 11.

Such a cotter member 10 is, for example,
As shown in FIG. 2, it is used as a shear connector when an earthquake-resistant wall 17 is added in an opening 16 surrounded by upper and lower columns 14 and 14 and left and right beams 15 and 15 in a building.

In this case, the cotter member 10 is
6 are arranged over the entire surface of the pillars 14, 14 and the beams 15, 15, and the protrusion 12 is formed in the opening 16.
It is adhered in a state facing inward. Then, in this state, the reinforcing bars (structural materials) 18, 18,
Are assembled in the opening 16 such that a part thereof is located between the protruding portions 12, 12,... Of the cotter members 10, 10,. It is possible to add an earthquake-resistant wall 17 in the opening 16.

In the above-described cotter member 10, since both the fixing portion 11 and the protruding portion 12 are formed of fiber reinforced concrete, compared with the case where the cotter member 10 is formed using ordinary concrete, Fixing unit 11
Shear strength between the protrusions 12 and the protrusions 12 can be secured. As a result, it is possible to expect a better seismic effect for the newly installed earthquake-resistant wall 17 than in the past.

In particular, since the above-mentioned cotter member 10 is formed of fiber reinforced concrete using ultra-lightweight concrete, it can be made lighter in weight and has excellent handling properties as compared with the prior art. This allows
It is possible to contribute to improvement of workability.

In addition, in the above-described method of adding the earthquake-resistant wall 17, since the cotter member 10 is formed of fiber-reinforced concrete, a constant shear strength can be expected for the cotter member 10. The strength of the joint between the earthquake-resistant wall 17 and the columns 14 and the beams 15 after the addition of the earthquake-resistant wall 17 can be expected, and a highly stable earthquake-resistant wall can be realized.

In particular, in this case, since the cotter member 10 is formed of fiber-reinforced concrete obtained by mixing a fiber material into ultra-lightweight concrete, the weight of the cotter member 10 can be reduced while ensuring the strength. In addition, the workability can be improved.

Further, the above-mentioned method of adding the earthquake-resistant wall 17 is as follows.
The plurality of cotter members 10, 10,...
Are arranged in the opening 16 such that a part thereof is located between the cotter members 10, 10,... And concrete is poured into the reinforcing bar 18. It is supposed to. Here, since the strength of the cotter member 10 is ensured, it is possible to transmit a good force between the reinforcing bar 18 and the cotter member 10, thereby improving the structural stability of the earthquake-resistant wall 17 to be added. Can be secured. In addition, since the cotter member 10 is formed to be lightweight, especially the pillar 1
The cotter member 10 can be easily attached to the four side surfaces and the lower surface of the beam 15, so that the construction labor can be reduced and the safety of work can be increased.

In the above embodiment, another configuration may be adopted without departing from the spirit of the present invention. For example, the shape of the cotter member 10 is not limited to the shape shown in FIG. 1, and another shape may be adopted.

[0028]

As described above, in the cotter member according to the first aspect, since both the fixing portion and the protruding portion are formed of fiber reinforced concrete, the cotter member is formed by using ordinary concrete. The shear strength between the fixing portion and the protruding portion can be ensured as compared with the case where it is formed. This makes it possible to ensure the strength and stability of the concrete structure to be added, as compared with the related art.

Since the cotter member according to the second aspect is formed of fiber reinforced concrete using ultra-lightweight concrete, it can be configured to be lighter than conventional and has excellent handling properties. Therefore, it is possible to contribute to improvement of workability.

According to a third aspect of the present invention, in the method of adding a concrete structure, a cotter member formed of fiber-reinforced concrete is used as a cotter member used when joining a concrete structure to be added to an existing member. A certain level of shear strength can be expected, and this will ensure the strength of the joint between the existing member and the concrete structure to be added, and realize a highly stable earthquake-resistant wall. Become.

According to a fourth aspect of the present invention, the cotter member is formed of fiber reinforced concrete obtained by mixing a fiber material into ultra-lightweight concrete. Can be achieved, and the workability can be improved.

According to a fifth aspect of the present invention, there is provided a concrete structure adding method, wherein a plurality of cotter members are attached around the opening.
In the opening, a reinforcing bar is arranged so that its end is located between the cotter members, and concrete walls are cast into the reinforcing bar to form an earthquake-resistant wall. In this case, since the strength of the cotter member is ensured, it is possible to transmit a good force between the end of the reinforcing bar and the cotter member, thereby securing the structural stability of the earthquake-resistant wall to be added. can do. In addition, since the cotter member is formed to be lightweight, it is possible to easily attach the cotter member to the column side surface or the lower surface of the beam as compared with the related art, and it is possible to reduce the construction labor. In addition, work safety can be increased.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a cotter member according to an embodiment of the present invention.

FIG. 2 is an elevation view showing one step of a method of adding a shear wall using the cotter member shown in FIG.

FIG. 3 is a vertical sectional view of a conventional cotter member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cotter member 11 Fixing part 12 Projecting part 14 Column 15 Beam 16 Opening 17 Earthquake-resistant wall 18 Steel bar (structural material)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) E04G 23/02 E04G 23/02 D (72) Inventor Yutaka Saito 2-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F Term (reference) 2E002 EB13 FA04 FB03 HA02 HB09 JA01 JA02 JB09 MA01 MA09 2E125 AA04 AA14 AA54 AB12 AE04 AE07 BA07 BB09 BB12 BD00 BD06 BE02 BE08 BF01 CA81 EA33 2E176 AA01 BB28

Claims (5)

[Claims] When a newly added concrete structure is connected to an existing member, the cotter member is attached as a shear connector to a position of the existing member to be joined to the concrete structure, A cotter member comprising: a fixing portion attached to an existing member; and a projecting portion projecting from the fixing portion, wherein both the fixing portion and the projecting portion are formed of fiber-reinforced concrete. 2. The cotter member according to claim 1, wherein the fiber reinforced concrete is formed by mixing a fiber material into ultra-lightweight concrete. 3. A method for connecting a concrete structure to an existing member and expanding the structure, wherein a cotter member is attached to a joining target position of the concrete structure in the existing member, and the cotter member is attached to the cotter member. The concrete structure is formed by casting concrete so as to be connected to form the concrete structure, and using a cotter member made of fiber-reinforced concrete. 4. The method according to claim 3, wherein the fiber reinforced concrete is formed by mixing a fiber material into ultra-lightweight concrete. Expansion method. 5. The method for adding a concrete structure according to claim 4, wherein the concrete structure is an earthquake-resistant wall that is added inside an opening surrounded by columns and beams in the building, and The existing member is the column and the beam, a plurality of cotter members are attached around the opening, and a structural material constituting the earthquake-resistant wall is partially provided between the cotter members in the opening. Placed so that
A method of adding a concrete structure, wherein the earthquake-resistant wall is formed by placing concrete on the structural material.