JP2009174249A - Reinforcing structure and reinforcing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing structure of a concrete member and a reinforcing method for the concrete member for obtaining excellent reinforcement effect simply and inexpensively. <P>SOLUTION: This reinforcing structure 1 is provided with a building foundation 10 being the existing concrete member, reinforcing bars 21 arranged on a surface of the building foundation 10, and polymer cement mortar 22 applied on the surface of the building foundation 10 while including the reinforcing bars 21 in its inside. A groove 13 having depth of 1/2 of diameter of the reinforcing bar 21 or more is formed at positions corresponding to the reinforcing bars 21 and the reinforcing bars 21 are arranged while a part of cross section of the reinforcing bar 21 is inserted into the groove 13 on the surface of the building foundation 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a reinforcing structure and a reinforcing method for an existing concrete member.

At present, the foundation of detached houses is basically a reinforced concrete foundation with shear reinforcement bars.
However, among the foundations of existing buildings, there are many unfounded concrete foundations and concrete foundations that are not properly arranged due to the construction based on the old Building Standard Law. It is necessary to reinforce such building foundations in order to ensure the desired earthquake resistance.

  Conventionally, as a method for reinforcing a foundation of a building, there is a case where the cross-sectional area of a member is increased by increasing the strength of shear strength by hitting reinforced concrete.

  Reinforced structure with reinforced concrete consists of installation of anchors to integrate the existing part (existing concrete member) and the new part (reinforced concrete part), rebar reinforcement, formwork installation, concrete placement However, it was constructed by concrete curing, and had the problem that it took time and labor to perform the construction.

  Therefore, conventionally, a method of reinforcement using polymer cement mortar has been disclosed as a reinforcing structure that can be constructed by simple construction and can reduce the work period and cost.

For example, in Patent Document 1, as shown in FIG. 5, the reinforcement structure 101 of the building foundation 110 includes reinforcement reinforcement 121 along the rising portion 111 of the existing building foundation 110 and application of polymer cement mortar. By doing so, the one that widens the cross-sectional shape of the rising portion 111 and enhances the shear strength is disclosed.
In addition, the reinforcement structure using a polymer cement mortar is employ | adopted for the reinforcement of not only the foundation (building foundation 110) of a detached house but all concrete members.
JP 2006-233671 A

  However, since the conventional reinforcing structure 101 uses a relatively expensive polymer cement mortar, there is a problem that the cost may increase when the reinforcing area is large.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to propose a reinforcing structure and a reinforcing method for a concrete member that can obtain an excellent reinforcing effect simply and inexpensively. .

  In order to solve such problems, the reinforcing structure of the present invention includes an existing concrete member, a reinforcing bar arranged on the surface of the existing concrete member, and the existing concrete member in a state including the reinforcing bar therein. A polymer cement mortar coated on the surface of the existing concrete member, the surface of the existing concrete member having a depth of 1/2 or more of the reinforcing bar diameter at a position corresponding to the reinforcing bar. A groove is formed, and the reinforcing bar is arranged in a state where a part of the cross section is inserted into the groove.

According to such a reinforcing structure, it is possible to reduce the thickness of the polymer cement mortar to be applied while securing the covering thickness necessary for the reinforcing bar by embedding the reinforcing bar in the groove. Therefore, the material cost can be reduced by reducing the amount of the entire polymer cement mortar used.
Moreover, since the adhesion area of the polymer cement mortar and the surface of the existing concrete member becomes large because the groove is formed on the surface of the existing concrete member, a more excellent adhesion effect can be obtained.

  Further, the reinforcing method of the present invention includes a step of forming a groove on the surface of an existing concrete member, a step of arranging reinforcing bars along the groove, the groove is filled and the reinforcing bar is embedded. And a step of applying polymer cement mortar to the surface of the existing concrete member, and the reinforcing bar is arranged in a state where a part of the cross section is inserted into the groove.

  According to such a reinforcing method, it is possible to improve the earthquake resistance of the existing concrete member by simple construction.

  According to the reinforcing structure and the reinforcing method of the present invention, it is possible to obtain an excellent reinforcing effect simply and inexpensively.

Preferred embodiments of the present invention will be described below with reference to the drawings. In the description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted.
Here, FIG. 1 is a perspective view showing the reinforcing structure according to the first embodiment, and FIG. 2 is an enlarged sectional view of the reinforcing structure shown in FIG. FIGS. 3A and 3B are perspective views showing respective steps of the reinforcing method according to the first embodiment. FIG. 4 is a perspective view showing a reinforcing structure according to the second embodiment.

<First Embodiment>
In the first embodiment, as shown in FIG. 1, a reinforcing structure 1 that reinforces an existing low-rise housing foundation (hereinafter simply referred to as “building foundation”) 10 will be described.

  As shown in FIG. 1, the reinforcing structure 1 includes an existing building foundation (existing concrete member) 10 and a reinforcing portion 20 formed on the surface of the building foundation 10. The reinforcing portion 20 includes reinforcing bars 21 arranged on the surface of the building foundation 10 and polymer cement mortar 22 coated on the surface of the building foundation 10 with a predetermined thickness in a state including the reinforcing bars 21 inside. It is prepared for.

  As shown in FIG. 1, the building foundation 10 is a reinforced concrete member formed by a rising portion 11 and a footing portion 12 in an inverted T-shaped cross section. In the present embodiment, reinforcement is performed by integrally forming the reinforcing portion 20 on the surface of the rising portion 11. In addition, the structure of the building foundation 10 which can apply the reinforcement structure 1 is not limited, It can apply to all concrete building foundations. The building foundation 10 may be an unreinforced concrete member.

As shown in FIGS. 1 and 2, on the surface of the rising portion 11, grooves 13 are vertically formed in two steps along the longitudinal direction corresponding to the reinforcing bars 21 (reinforcing main bars 21 a).
The groove 13 has a depth of 1/2 or more of the reinforcing bar diameter of the reinforcing bar 20 (reinforcing main bar 21a) and a width (reinforcing main bar) that is about 1 cm larger than the reinforcing bar diameter D of the reinforcing bar 20 (reinforcing main bar 21a). The width is formed so that a gap of about 5 mm is formed above and below 21a. The width of the groove 13 is not limited and can be set as appropriate.

  In the present embodiment, the cross-sectional shape of the groove 13 is formed in a rectangular shape, but may be a semicircular shape, for example, and the cross-sectional shape of the groove 13 is not limited. Further, the dimensions such as the width and depth of the groove 13 are not limited and can be set as appropriate.

  The reinforcing bar 21 is a reinforcing bar embedded in the reinforcing part 20 in a state where a predetermined covering thickness C is secured. The reinforcing bar 21 has a reinforcing reinforcing bar 21a that is arranged along the longitudinal direction (lateral direction) of the rising portion 11 and a shear reinforcing bar 21b that is arranged in a direction (vertical direction) perpendicular to the reinforcing main bar 21a. ing.

  As shown in FIG. 2, the reinforcing main bars 21 a are arranged in a state where a part of the cross section (substantially half in the present embodiment) is inserted into the groove 13. On the other hand, the shear reinforcement bars 21b are arranged so as to intersect with the reinforcement main bars 21a in a state where the shear reinforcement bars 21b are in contact with the surface of the reinforcement main bars 21a opposite to the rising portions 11 thereof.

  In this embodiment, as shown in FIG. 2, the reinforcing bars 21 are arranged using anchors 23 arranged at the intersections between the reinforcing main bars 21a and the shear reinforcing bars 21b. In addition, although the structure of the anchor 23 is not limited, a post-construction anchor is used in this embodiment. Further, the anchor 23 may be used as necessary, and may be omitted.

  The polymer cement mortar 22 is applied so as to cover the surface of the rising portion 11 so that the reinforcing bars 21 are embedded.

In the present embodiment, the thickness of the polymer cement mortar 22 is set as a covering thickness C of the reinforcing bar 21 to a thickness that can secure 2D (twice the diameter of the reinforcing bar) or more from the surface of the shear reinforcing bar 21b.
Moreover, the reinforcement part 20 is aiming at the improvement of joining property with the standing part 11 by filling the polymer cement mortar 22 also into the groove | channel 13. FIG.

In this embodiment, the polymer cement mortar 22 has a bending strength of 6 N / mm ² or more, a compressive strength of 20 N / mm ² or more, an adhesive strength of 1 N / mm ² or more, and an adhesive durability of 1 N / mm ² or more. However, the strength and the like of the polymer cement mortar 22 are not limited.

Next, a reinforcing method according to the first embodiment will be described.
The reinforcing method according to the present embodiment includes a grooving step, a bar arrangement step, and a coating step.

  The grooving step is a step of forming the groove 13 by cutting the surface of the rising portion 11 as shown in FIG.

  The groove 13 is formed by using a groove cutter (not shown), and the surface of the rising 11 is cut along the longitudinal direction to obtain a predetermined width (rebar diameter D + 1 cm) and depth (rebar diameter D / A groove 13 having 2) is formed. The configuration of the groove cutter is not limited, and may be appropriately selected from known cutters.

  As shown in FIG. 3B, the reinforcing bar is a step of arranging reinforcing bars 21 including reinforcing main bars 21a and shear reinforcing bars 21b along the surface of the rising portion 11 where the grooves 13 are formed.

  As shown in FIG. 2, the reinforcing main bars 21 a are arranged along the grooves 13 formed in the grooving step, and are arranged in a state where approximately half of the cross section of the reinforcing main bars 21 a is inserted into the grooves 13. . In the present embodiment, the reinforcing main bars 21a are arranged with a predetermined gap (2 mm in this embodiment) opened from the bottom surface of the groove 13, but the reinforcing main bars 21a may be in contact with the bottom surface of the groove 13. Good.

As shown in FIGS. 2 and 3 (b), the shear reinforcement bars 21b are arranged in contact with the reinforcement main bars 21a so as to intersect the reinforcement main bars 21a. In this embodiment, the reinforcing bars 21 (reinforcement reinforcing bars 21a and shear reinforcing bars 21b) are assembled without reducing the strength of the reinforcing bars by the welded reinforcing bars, but the assembling method is not limited to the reinforcing bars 21, for example. You may assemble by bundling.
In the present embodiment, the reinforcing bars 21 are fixed using the anchor 23 having one end embedded in the rising portion 11.

  The coating step is a step of applying polymer cement mortar 22 to the surface of the rising portion 11 where the reinforcing bars 21 are arranged, and the thickness is such that the reinforcing bars 21 are filled with the grooves 13 and a predetermined covering thickness C can be secured. And

  In this embodiment, the application of the polymer cement mortar 22 is performed in three stages of base coating, first layer coating, and second layer coating. It is not limited.

  The undercoating is an operation of spraying the polymer cement mortar 22 with a thickness of about 2 to 3 mm on the surface of the rising portion 11 along with the filling of the groove 13, and to improve the adhesion between the rising portion 11 and the reinforcing portion 20. Do as purpose. The undercoating of the polymer cement mortar 22 is not limited to spraying and may be performed by applying.

  In the first layer coating, the polymer cement mortar 22 is applied to the extent that the reinforcing bar 21 is buried, and is an operation performed so that no cavity is generated around the reinforcing bar 20.

  The second layer coating is an operation for applying the polymer cement mortar 22 and finishing the surface of the reinforcing portion 20 so that the designed thickness of the reinforcing portion 20 can be secured.

  As described above, according to the reinforcing structure and the reinforcing method according to the first embodiment, the reinforcing portion 20 is arranged in a state where the reinforcing main reinforcement 21a is inserted into the groove 13, and therefore the thickness of the polymer cement mortar 22 is reduced. Is possible. Therefore, the cost can be reduced by reducing the amount of the relatively expensive polymer cement mortar 22.

  Further, since the reinforcing part 20 is filled with the polymer cement mortar 22 in the groove 13 as well, it has excellent bending stress transmission and can perform high-quality reinforcement.

  Moreover, since the bonding area is increased by the groove 13, the building foundation 10 and the reinforcing portion 20 are more firmly integrated.

In addition, unlike conventional thickened concrete, construction can be performed easily without the need for work steps such as installation of molds, curing of concrete, and removal of molds.
Moreover, since the width of the groove 13 is formed to be about 1 cm larger than the reinforcing bar diameter D, a gap of 5 mm can be secured between the groove and the reinforcing bar, and the filling property of the polymer cement 22 into the groove 13 is improved. While improving, it becomes easy to push the reinforcing bar 21 into the groove | channel 13, and it is excellent in workability | operativity.

<Second Embodiment>
In 2nd Embodiment, as shown in FIG. 4, the reinforcement structure 2 which reinforces the wall member 30 which is an existing concrete structure is demonstrated.

  As shown in FIG. 4, the reinforcing structure 2 includes an existing reinforced concrete wall member (existing concrete member) 30 and a reinforcing portion 40 integrally formed on the surface of the wall member 30. The reinforcing portion 40 includes reinforcing bars 41 arranged along the surface of the wall member 30, and a polymer cement mortar 42 coated with a predetermined thickness on the surface of the wall member 30 with the reinforcing bars 41 included therein. And is configured.

  The configuration of the existing concrete member to which the reinforcing structure 2 can be applied is not limited to the wall member 30 and can be applied to any concrete member. The wall member 30 may be an unreinforced concrete member.

As shown in FIG. 4, a plurality of rows of grooves 31, 31,... Are formed on the surface of the wall member 30 in the vertical direction corresponding to the reinforcing bars 41 (vertical bars 41 a).
The groove 31 has a depth of 1/2 or more of the reinforcing bar diameter of the reinforcing bar 40 (vertical bar 41a), and a width (vertical bar 41a) larger by about 1 cm than the reinforcing bar diameter of the reinforcing bar 40 (vertical bar 41a). Are formed on the left and right sides of each of them so that a gap of about 5 mm is formed. The width of the groove 31 is not limited and can be set as appropriate.

  In the present embodiment, the cross-sectional shape of the groove 31 is formed in a rectangular shape, but may be a semicircular shape, for example, and the cross-sectional shape of the groove 31 is not limited. Also, the dimensions such as the width and depth of the groove 31 are not limited and can be set as appropriate.

  The reinforcing bar 41 is a reinforcing bar embedded in the reinforcing part 40 in a state where a predetermined covering thickness is secured. The reinforcing bars 41 are assembled in a lattice shape by vertical bars 41a and horizontal bars 41b. The configuration of the reinforcing bar 41 is not limited. In the present embodiment, the reinforcing bars 41 are assembled with welded reinforcing bars without lowering the strength of the reinforcing bars, but the assembling method of the reinforcing bars 41 is not limited and may be performed by bundling.

  The longitudinal bars 41a are arranged in a state where a part of the cross section (half in the present embodiment) is inserted into the groove 31 (see FIG. 2). On the other hand, the horizontal bars 41b are arranged so as to intersect the vertical bars 41a in a state where the horizontal bars 41b are in contact with the surface of the vertical bars 41a opposite to the wall member 30.

  The polymer cement mortar layer 42 is formed by applying the polymer cement mortar 42 to the surface of the wall member 30 in a state including the reinforcing bars 41.

In the present embodiment, the thickness of the polymer cement mortar 42 is set as the covering thickness C of the reinforcing bar 41 so as to ensure a thickness of 2D (twice the diameter of the reinforcing bar) or more from the surface of the horizontal bar 41b.
Moreover, the reinforcement part 40 is improving the joining property with the wall member 30 because the polymer cement mortar 42 is filled also into the groove | channel 31. FIG.

  In addition, since the polymer cement mortar 42 used in this embodiment is the same as that shown in the first embodiment, detailed description thereof is omitted.

  Moreover, since the construction of the concrete structure reinforcement structure according to the second embodiment is performed in the same manner as the reinforcement method shown in the first embodiment, detailed description thereof is omitted.

As mentioned above, according to the reinforcement structure 2 and the reinforcement method which concern on this embodiment, it becomes possible to improve the earthquake resistance of the existing wall member simply and cheaply.
Further, since the reinforcing bars 41 are arranged with the vertical bars 41a inserted in the grooves 31, the thickness of the polymer cement mortar 42 can be reduced. Therefore, the cost can be reduced by reducing the amount of the polymer cement mortar 42 used for reinforcing the wall member 30 with a large construction area.

  Moreover, according to the reinforcement structure 2, since the proof stress of a wall member can be increased, it becomes possible to reinforce an existing structure without shielding an opening, such as a steel brace.

  In addition, since the effect by the reinforcement structure of the concrete structure which concerns on 2nd Embodiment is the same as the content shown in 1st Embodiment, detailed description is abbreviate | omitted.

As mentioned above, although preferred embodiment was described about this invention, this invention is not limited to said each embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention.
For example, the concrete structure to which the reinforcing structure and the reinforcing method of the concrete structure of the present invention can be applied is not limited to a building foundation or a wall member. For example, an existing beam member can be applied to any concrete member such as a column. Is possible.

  The method for applying the polymer cement mortar is not limited, and may be appropriately performed by known means.

It is a perspective view which shows the reinforcement structure of the concrete structure which concerns on suitable embodiment of this invention. It is an expanded sectional view of the reinforcement structure of the concrete structure shown in FIG. (A) And (b) is a perspective view which shows each process of the reinforcement method of the concrete structure concerning 1st Embodiment. It is a perspective view which shows the reinforcement structure of the concrete structure concerning other suitable embodiment of this invention. It is a figure which shows the reinforcement structure of the conventional concrete structure, Comprising: (a) is a perspective view, (b) is an expanded sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Reinforcement structure 10 Building foundation 11 Standing part 13 Groove 20 Reinforcement part 21 Reinforcement reinforcement 21a Reinforcement reinforcement 22 Polymer cement mortar 30 Wall member 31 Groove 40 Reinforcement part 41 Reinforcement reinforcement 41a Longitudinal reinforcement 42 Polymer cement mortar

Claims (2)

Existing concrete members,
Reinforcing bars arranged on the surface of the existing concrete member;
A polymer cement mortar coated on the surface of the existing concrete member in a state of including the reinforcing bar inside, a reinforcing structure comprising:
On the surface of the existing concrete member, a groove having a depth of 1/2 or more of the reinforcing bar diameter of the reinforcing bar is formed at a position corresponding to the reinforcing bar,
The reinforcing structure is characterized in that the reinforcing bars are arranged in a state where a part of a cross section is inserted into the groove. Forming a groove on the surface of an existing concrete member;
Arranging reinforcing bars along the grooves;
Applying the polymer cement mortar to the surface of the existing concrete member so that the groove is filled and the reinforcing bar is embedded, and a reinforcing method comprising:
The reinforcing method is characterized by arranging the reinforcing bars in a state where a part of the cross section is inserted into the groove.

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