Reinforced concrete column structure, and construction method of the same

Abstract

To provide a reinforced concrete column structure that enables relatively easy joining of a base portion and a precast concrete column member.SOLUTION: A reinforced concrete column structure 1 comprises a foundation 10 and a precast concrete column member 20 joined to the foundation 10. A convex cotter portion 40 is formed on an upper surface of the foundation 10, and a recess 24 is formed on a lower end surface of the column member 20. The cotter portion 40 is fitted into the recess 24, and a lower end portion of a column main reinforcement 22 of the column member 20 is located inside the column member 20.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a reinforced concrete column structure including a base portion and a precast concrete (PC) column member, and a method for constructing the reinforced concrete column structure.

Background Art

[0002] Conventionally, the following structures have been proposed as methods for joining precast concrete members (see Patent Documents 1 and 2). Patent Document 1 shows a joining structure between a reinforced concrete column member and a reinforced concrete support body that supports the column member. A recess is formed on the upper surface of the support body, and the column foot portion of the column member is fitted into the recess to form a joint portion. A groove is provided on the surface side of the support body in the joint portion to block the force transmitted between the inner wall surface of the recess and the side surface of the column foot portion side of the column member.

[0003] Patent Document 2 shows a lifting mechanism provided in a columnar body extending in the vertical direction. The lifting mechanism includes an upper plate fixed to the lower surface of the upper body, a lower plate fixed to the upper surface of the lower body, a shear key protruding from the upper surface of the lower plate and slidably inserted in a vertical direction through a through hole provided in the upper plate, and a buffer material disposed between the upper plate and the lower plate and absorbing the vertical impact.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a reinforced concrete column structure and a construction method thereof that can join a base portion and a precast concrete column member relatively easily.

Means for Solving the Problems

[0006] As a reinforced concrete column structure including a base portion and a PC column member joined to this base portion, the inventors install the column member on the base portion while fitting a recess formed on the lower end surface of the column member into a convex cotter portion formed on the base portion, without fixing the column main reinforcement of the column member inside the base portion. As a result, it is not necessary to arrange the column main reinforcement inside the base portion, and since part of the work of arranging the column main reinforcement is reduced, the base portion and the column member can be joined relatively easily, and it is possible to shorten the construction period. The reinforced concrete column structure of the first invention (for example, the reinforced concrete column structure 1 described later) is a reinforced concrete column structure including a base portion (for example, the foundation 10 described later) and a precast concrete column member (for example, the column member 20 described later) joined to the base portion, wherein the base portion is a foundation, a slab, or a lower floor column, a convex cotter portion (for example, the cotter portion 40 described later) is formed on the upper surface of the base portion, a recess (for example, the recess 24 described later) is formed on the lower end surface of the column member, the cotter portion is fitted into the recess, and the lower end portion of the column main reinforcement (for example, the column main reinforcement 22 described later) of the column member is located inside the column member.

[0007] According to this invention, a convex cotter portion is formed on the base portion, which is a foundation, a slab, or a lower floor column, a recess is formed on the lower end surface of the column member, and the base portion and the column member are joined by fitting the cotter portion of the base portion into the recess of the column member. By fitting the cotter portion and the recess, it is not necessary to fix the column main reinforcement of the column member inside the base portion, and the base portion and the precast concrete column member can be joined relatively easily. In addition, since it is not necessary to arrange the column main reinforcement inside the base portion, part of the work of arranging the column main reinforcement can be reduced, and the construction period can be shortened.

[0008] In the reinforced concrete column structure of the second invention, a vertical steel material (for example, the vertical steel material 41 described later) extending upward from the base portion is embedded in the cotter portion, and a post-cast portion (for example, the floor slab 15 described later) formed by post-casting concrete is provided on the upper surface of the base portion. The column leg portion of the column member is characterized by being embedded in the post-cast portion of the base portion.

[0009] According to this invention, since the column leg portion of the column member is embedded in the post-cast portion of the base portion, the joint strength between the base portion and the column member is increased. Therefore, a reinforced concrete column structure excellent in seismic performance can be provided. In addition, since the vertical steel material extending upward from the base portion is embedded inside the cotter portion, the vertical steel material resists against the horizontal shear force acting on the joint portion between the base portion and the column member, in addition to the cotter portion and the concave portion. Therefore, the shear resistance of the joint portion between the base portion and the column member can be improved.

[0010] A construction method of a reinforced concrete column structure of the third invention is a construction method of a reinforced concrete column structure (for example, the reinforced concrete column structure 1 described later) including a base portion (for example, the foundation 10 described later) and a precast concrete column member (for example, the column member 20 described later) joined to the base portion. The method includes a step of constructing a base portion which is a foundation, a slab, or a lower floor column and has a convex cotter portion (for example, the cotter portion 40 described later) formed on the upper surface (for example, steps S11 and S12 described later), a step of preparing a column member having a concave portion (for example, the concave portion 24 described later) formed on the lower end surface, suspending the column member from above the base portion, and fitting the cotter portion of the base portion into the concave portion of the column member (for example, step S13 described later), and a step of injecting a filler (for example, the one described later) into the gap between the base portion and the column member to join the base portion and the column member (for example, step S15 described later).

[0011] According to the present invention, a cotter part is formed on a base part which is a foundation, a slab, or a lower-story column, a recess is formed on the lower end surface of a column member, and the column member is joined to the base part by fitting the recess of the column member into the cotter part of the base part. Thereby, the base part and the precast concrete column member can be joined relatively easily. In addition, since it is not necessary to arrange the main column reinforcing bars inside the base part, a part of the work of arranging the main column reinforcing bars can be reduced, and the construction period can be shortened.

Effects of the Invention

[0012] According to the present invention, it is possible to provide a reinforced concrete column structure and a construction method thereof that can join a base part and a precast concrete column member relatively easily.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

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Figure 8

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Figure 10

Figure 11

Figure 12

Embodiment for Carrying out the Invention

[0014] The present invention is a reinforced concrete column structure including a base portion and a PC column member joined to the base portion. While fitting a recess formed on the lower end surface of the column member into a convex cotter portion formed on the base portion, it is a reinforced concrete column structure in which the column member is installed on the base portion. In this reinforced concrete column structure, since the main column bars of the column member are not fixed inside the base portion, a part of the bar arrangement work of the main column bars is reduced, so that the base portion and the column member can be joined relatively easily, and the construction period can be shortened. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1(a) is a longitudinal sectional view of a reinforced concrete column structure 1 according to an embodiment of the present invention. FIG. 1(b) is a side view of a column member 20 constituting the reinforced concrete column structure 1. The reinforced concrete column structure 1 includes a foundation 10 as a base portion, a precast concrete column member 20 joined to the foundation 10, and a steel beam member 30 joined to the upper end portion of the column member 20.

[0015] FIG. 2 is an enlarged view of a portion (the foundation 10 and the column foot portion of the column member 20) surrounded by a broken line A of the reinforced concrete column structure 1 in FIG. 1. FIG. 3 is a C-C sectional view of the foundation 10 in FIG. 2. FIG. 4(a) is a D-D sectional view of the column member 20 in FIG. 2. FIG. 4(b) is an E-E sectional view of the column member 20 in FIG. 2. The foundation 10 includes an X-direction foundation beam 11 extending substantially horizontally in the X direction, a Y-direction foundation beam 12 extending substantially horizontally in the Y direction intersecting the X-direction foundation beam 11, a foundation beam intersection portion 13 where the X-direction foundation beam 11 and the Y-direction foundation beam 12 intersect, and a footing 14 supporting the foundation beam intersection portion 13. The foundation 10 includes a concrete body 16, main beam reinforcement bars 17 arranged inside the concrete body 16, and stirrups 18 wound around the main beam reinforcement bars 17 at predetermined intervals.

[0016] On the upper surface of the foundation beam intersection part 13, a convex cotter part 40 is formed. In the cotter part 40, a vertical steel material 41 extending upward from the foundation beam intersection part 13 is embedded. On the upper surface of the foundation beam intersection part 13, a floor slab 15 as a cast - in - place part is constructed by casting concrete later. The column feet of the column member 20 are embedded in this floor slab 15.

[0017] The column member 20 is a rod - shaped member extending in the vertical direction, and includes a concrete body 21, vertical column main reinforcement bars 22 arranged inside the concrete body 21, and stirrup bars 23 wound around the vertical column main reinforcement bars 22 at predetermined intervals. As shown in FIG. 2, the lower end part of the column main reinforcement bar 22 is located inside the column member 20 and does not protrude downward from the lower end surface of the column member 20. Moreover, a concave part 24 is formed on the lower end surface of the concrete body 21 of the column member 20. The cotter part 40 of the foundation 10 is fitted into this concave part 24, and the gap between the foundation 10 and the column member 20 is filled with non - shrinkage mortar 25.

[0018] FIG. 5(a) is an enlarged view of the portion (the column head part of the column member 20 and the steel - framed beam member 30) surrounded by the broken line B of the reinforced concrete column structure 1 in FIG. 1. FIG. 5(b) is a view taken along the line F - F of the reinforced concrete column structure 1 in FIG. 5(a). FIG. 6 is a cross - sectional view taken along the line G - G of the column member 20 in FIG. 5(a). At the upper end part of the column member 20, a joint plate 26 extending upward and a stiffening member 27 for stiffening this joint plate 26 are provided. At the lower part of the joint plate 26, headed studs 28 are provided at predetermined intervals and are embedded in the concrete body 21 of the column member 20.

[0019] The steel frame beam member 30 includes an X-direction steel frame beam 31 that extends substantially horizontally in the X direction, a Y-direction steel frame beam 32 that extends substantially horizontally in the Y direction and intersects the X-direction steel frame beam 31, and a steel frame beam intersection portion 33 where the X-direction steel frame beam 31 and the Y-direction steel frame beam 32 intersect. At the steel frame beam intersection portion 33, a joining plate 34 that extends downward and a stiffening member 35 that stiffens the joining plate 34 are provided. The joining plate 34 of the steel frame beam member 30 and the joining plate 26 of the column member 20 are sandwiched between a pair of splice plates 36 and joined by bolts 37 and nuts 38.

[0020] Hereinafter, the procedure for forming the cotter portion 40 on the upper surface of the foundation 10 will be described with reference to the flowchart of FIG. 7. Specifically, as shown in FIG. 8, a precast concrete cotter member 42 is prepared, and the cotter portion 40 is formed by fitting this cotter member 42 into the recess 44 on the upper surface of the foundation 10 (see FIG. 10). A through hole 43 that penetrates vertically is formed in the cotter member 42, and the inner diameter of this through hole 43 is larger than the outer diameter of the vertical steel material 41. First, the vertical steel material 41 is buried and constructed in the foundation 10 in advance. As a result, the vertical steel material 41 protrudes upward from the upper surface of the foundation beam intersection portion 13.

[0021] In step S1, as shown in FIG. 9(a), the upper surface of the foundation beam intersection portion 13 and the periphery of the vertical steel material 41 are chiseled to form the recess 44. In step S2, as shown in FIG. 9(a), non-shrink mortar 46 is poured into this recess 44 and leveled to form a bottom surface 45 for placing the cotter member 42. The height of the cotter member 42 can be adjusted by appropriately adjusting the amount of non-shrink mortar poured into the recess 44. In step S3, as shown in FIG. 9(b), while inserting the vertical steel material 41 into the through hole 43, the cotter member 42 is placed on the bottom surface 45 of the recess 44. In step S4, as shown in FIG. 9(b), the horizontal positioning of the cotter member 42 is performed. Since the inner diameter of the through hole 43 of the cotter member 42 is larger than the outer diameter of the vertical steel material 41, the horizontal position adjustment of the cotter member 42 is easy. In step S5, as shown in FIG. 10, non-shrink mortar 47 is filled into the gap between the cotter member 42 and the recess 44, and the gap between the vertical steel material 41 and the through-hole 43 of the cotter member 42 to fix the cotter member 42 to the recess 44. Thereby, the cotter part 40 is formed on the upper surface of the foundation 10.

[0022] Hereinafter, the procedure for constructing the reinforced concrete column structure 1 will be described with reference to the flowchart of FIG. 11. In step S11, as shown in FIG. 12(a), the foundation 10 is constructed. In step S12, the cotter part 40 is formed on the foundation 10 by the procedures of the above-described steps S1 to S5. In step S13, as shown in FIG. 12(a), the column member 20 is prepared, and this column member 20 is lifted and suspended from above the foundation 10, and the cotter part 40 of the foundation 10 is fitted into the recess 24 of the column leg part of the column member 20. In step S14, as shown in FIG. 12(b), the steel frame beam member 30 is joined to the column head part of the column member 20, and the embedding of the column member 20 is adjusted. In step S15, as shown in FIG. 2, non-shrink mortar 25 is filled into the gap between the foundation 10 and the column member 20 to join the foundation 10 and the column member 20. In step S16, the floor slab 15 is constructed by post-casting, and the column leg part of the column member 20 is embedded in the floor slab 15.

[0023] According to the present embodiment, there are the following effects. (1) By forming the convex cotter part 40 on the foundation 10, forming the recess 24 on the lower end surface of the column member 20, and fitting the cotter part 40 of the foundation 10 into the recess 24 of the column member 20, the foundation 10 and the column member 20 are joined. Due to the fitting of the cotter part 40 and the recess 24, it is not necessary to fix the column main reinforcement 22 of the column member 20 inside the foundation 10, and the foundation 10 and the precast concrete column member 20 can be joined relatively easily. In addition, since it is not necessary to arrange the column main reinforcement 22 inside the foundation 10, a part of the work of arranging the column main reinforcement 22 can be reduced, and the construction period can be shortened.

[0024] (2) Since the column base of the column member 20 is embedded in the floor slab 15 of the foundation 10, the joint strength between the foundation 10 and the column member 20 is increased. Therefore, a reinforced concrete column structure excellent in seismic performance can be provided. In addition, since the vertical steel material 41 extending upward from the foundation 10 is embedded inside the cotter part 40, the vertical steel material 41 resists against the horizontal shear force acting on the joint part between the foundation 10 and the column member 20, in addition to the cotter part 40 and the recessed part 24. Therefore, the shear strength of the joint part between the foundation 10 and the column member 20 can be improved.

[0025] Note that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention. For example, in the present embodiment, the cotter part 40 is provided on the upper surface of the foundation 10 and the cotter part 40 is fitted into the recessed part 24 of the column member 20. However, the present invention is not limited to this, and a cotter part may be provided on the upper surface of a slab or a lower floor column, and the cotter part may be fitted into the recessed part 24 of the column member 20.

Explanation of reference numerals

[0026] 1... Reinforced concrete column structure 10... Foundation (base part) 11... X-direction foundation beam 12... Y-direction foundation beam 13... Foundation beam intersection 14... Footing 15... Floor slab (cast-in-place part) 16... Concrete body 17... Main beam reinforcement 18... Stirrup 20... Column member 21... Concrete body 22... Main column reinforcement 23... Hoop 24... Recessed part 25... Non-shrink mortar 26... Joint plate 27... Bracing member 28... Stud 30... Steel beam member 31... X-direction steel beam 32... Y-direction steel beam 33... Steel beam intersection 34... Joint plate 35... Bracing member 36... Splice plate 37... Bolt 38... Nut 40... Cotter part 41... Vertical steel material 42... Cotter member 43... Through hole 44... recess 45... bottom surface of the recess 46, 47... non-shrinking mortar

Claims

1. A reinforced concrete column structure comprising a base portion and a precast concrete column member joined to the base portion, wherein the base portion is a foundation, a slab, or a lower floor column, a convex cotter portion is formed on the upper surface of the base portion, a concave portion is formed on the lower end surface of the column member, the cotter portion is fitted into the concave portion, and a lower end portion of the main reinforcement bars of the column member is located inside the column member. A reinforced concrete column structure characterized by this.

2. A vertical steel material extending upward from the base portion is embedded in the cotter portion, a cast-in-place portion formed by casting concrete in a cast-in-place manner is provided on the upper surface of the base portion, and the column base portion of the column member is embedded in the cast-in-place portion of the base portion. The reinforced concrete column structure according to Claim 1, characterized by this.

3. A method for constructing a reinforced concrete column structure comprising a base portion and a precast concrete column member joined to the base portion, the step of constructing a base portion, which is a foundation, a slab, or a lower floor column, having a convex cotter portion formed on its upper surface, the step of preparing a column member having a concave portion formed on its lower end surface, suspending the column member from above the base portion, and fitting the cotter portion of the base portion into the concave portion of the column member, and the step of injecting a filler into the gap between the base portion and the column member to join the base portion and the column member. A method for constructing a reinforced concrete column structure characterized by comprising these steps.

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