JP2003113644A - Building method of precast concrete-made vertical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the building work of a precast concrete-made vertical member. SOLUTION: A recessed part 13 having an area wider than a built-up point A is formed on the upper surface of the concrete 11 of a connection part 10. A spacer 15 is placed in the built-up point A, and mortar 16 is poured into the recessed part 13. A PC column 20 is set in the built-up point A through a spacer 15 so that the main bar 12 of the connection part 10 is inserted under the joint 23 of the PC column 20. At this time, two or more joints 23 are mutually independent by the mortar 16, and the mortar 16 is spread over between the lower end circumference of the PC column 20 and the periphery of the recessed part 13. The positional adjustment of the PC column 20 is then carried out. Mortar 25 is then injected through the respective injection ports 23x of the joints 23 to fill their inner spaces 23a. The mortar 16 is flowable in the positional adjustment of the PC column 20, but harder than the mortar 25 in the injection of the mortar 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mounting a vertical member made of precast concrete in a lower structure part.

[0002]

2. Description of the Prior Art Made of precast concrete (hereinafter referred to as P
An example of a conventional method in which a column (referred to as C) (vertical member) is built in a joint section (lower structure section) made of cast-in-place concrete will be described.

The PC columns are a plurality of joints which are embedded in the lower end of concrete and whose internal space is opened to the lower end surface of the concrete, and which are vertically embedded in concrete and whose lower end is inserted or inserted into the upper part of the joint. And a plurality of main bars connected to each other. This joint has an inlet and an outlet above it, and these inlet and outlet are open to the side of the concrete. On the other hand, the main bar projects vertically upward from the concrete top surface of the joint.

When the PC pillar is built, hard mortar is applied to the concrete upper surface of the joint in advance. next,
Place the PC pillar on the floor mortar. At this time, the upper end portion of the main bar protruding from the upper surface of the joint concrete is inserted into the lower portion of the joint of the PC column. As a result, the PC pillars and the main bars of the joint portion are aligned in the same straight line and face each other in the joint. Immediately after this, the tilt adjustment and horizontal position of the PC column are adjusted, and finally, mortar is injected into each of the joints, and the main bars are connected by hardening thereof.

In the above method, since the mortar is hard, PC
When the inclination or horizontal position of the column is adjusted, there is a possibility that joint breakage (a state where the mortar is not completely filled) may occur between the lower end surface of the PC column and the concrete surface of the joint.

Therefore, the method disclosed in Japanese Patent Publication No. 4-52815 was developed. The structures of the PC column and the connection portion used in this method are the same as those of the above-mentioned conventional technique. However, no floor mortar is provided. In detail,
A spacer is placed on the concrete top surface of the joint, and a PC column is placed on it. At this time, the point where the upper and lower main bars face each other in the joint is the same as in the above-mentioned conventional technique. Next, the tilt adjustment and horizontal position adjustment of the PC column are performed. Further, a mold is provided on the outer periphery of the PC column, thereby closing the gap (joint part) between the lower surface of the PC column and the upper surface of the joint section. Finally, the joint is filled with mortar from the injection port formed in the mold, and further injection is continued to spread the mortar into the inner spaces of all joints connected to the joint.

[0007]

SUMMARY OF THE INVENTION In the method of the above publication,
Since the relatively soft mortar is poured into the joint after the position adjustment, the problem of joint breakage has been solved, but it takes skill and time to install the formwork on the outer circumference of the PC column without any gap, and one more note It also took skill to spread the mortar injected from the inlet to all joints. Japanese Patent Laid-Open No. 8-930
48, JP-A-10-147978, JP-A-2000-
The method disclosed in each publication of No. 352110 is also based on the same idea, and the same inconvenience occurred.

[0008]

A first aspect of the present invention is a method of building a vertical member made of precast concrete in a concrete lower structure portion, wherein the vertical member is embedded in a lower end portion of concrete. A plurality of tubular joints whose internal space is opened to the lower end surface of concrete,
It is embedded in concrete and extends vertically, and the lower end has a plurality of main bars inserted or connected to the upper part of the joint, and the joint has an inlet and an outlet above it. The outlet is opened to the side of the concrete, and the above-mentioned lower structure part is formed by vertically projecting a plurality of main bars from the planned construction site on the upper surface of the concrete,
(A) On the upper surface of the lower structure portion, there is provided an accommodating portion having a larger area than the planned installation position of the vertical member and having an open upper part, and a spacer is placed at the planned installation position and the accommodating part The mortar is housed in a space above the spacer, and (b) the main bar of the lower structure is inserted into the lower part of the joint of the vertical member, and the vertical member is planned to be installed in the lower structure through the spacer. , Thereby making the inner spaces of the joints independent of each other in the mortar housed in the housing part and spreading the mortar between the lower end outer periphery of the vertical member and the housing part periphery, and Adjust the position of the vertical member placed at the planned insertion location, and (d) fill the internal space by injecting mortar from each of the inlets of the above independent joints, and The mortar accommodated in the accommodating portion of the lower structure portion is connected to the vertical member and the main bars of the lower structure portion through the mortar and the joint at least when the position of the vertical member is adjusted. It is characterized in that it is soft and has fluidity so that it can be avoided, and is harder than the injected mortar when the mortar is injected into the joint.

A second aspect of the present invention is the method for assembling a vertical member made of precast concrete according to the first aspect, wherein the accommodating portion is recessed from the upper surface of the lower structure portion. A third aspect of the present invention is the precast concrete vertical member erection method of the second aspect, wherein the accommodating portion is partitioned by the concrete base material of the lower structure portion.

According to a fourth aspect of the present invention, in the method for assembling a vertical member made of precast concrete according to the first aspect, the accommodating portion of the lower structure portion is placed on the upper surface of the concrete of the lower structure portion and on it. It is divided by a separate formwork.

A fifth aspect of the present invention is the method for assembling a vertical member made of precast concrete according to any of the first to fourth aspects, wherein the level of mortar raised by placing the vertical member on a spacer corresponds to the depth of the accommodating portion. The method for building a vertical member made of precast concrete according to any one of claims 1 to 4, wherein the supply amount of the mortar to the accommodation portion is determined so as to be the same or shallower than this.

[0012]

DETAILED DESCRIPTION OF THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. In this embodiment,
The PC pillar 20 as a PC vertical member is built in the joint portion 10 as a lower structure portion.

As shown in FIG. 1, the joint portion 10 constitutes a joint portion between an existing lower PC column and a PC beam (neither is shown), and as shown in FIG. Beaten concrete 11 and top surface 1 of this concrete 11
1a (hereinafter referred to as a slab surface) and a plurality of main bars 12 that vertically project upward. In addition, this main line 12
The main bar of the lower PC column extends and is located in the vicinity of the four corners and four sides of the plan square built-in planned site A within the range.

On the slab surface 11a, a recess 13 (accommodation portion) having an area larger than that of the planned location A is formed. The concave portion 13 has a square planar shape, and has a horizontal bottom surface 13a and a peripheral edge composed of four inclined edge surfaces 13b. The concave portion 13 is formed when the concrete 11 is cast in place and is defined by the base material of the concrete 11. That is, the bottom surface 13a and the edge surface 13b of the recess 13 are exposed surfaces of the base material of the concrete 11. The four edge surfaces 13b of the concave portion 13 surround the planned building location A, and the upper edges of these edge surfaces 13b are equidistant from the respective edges of the planned building location A.

On the other hand, the PC pillar 20 is made of concrete 2
1 and a plurality of main bars 22 and a plurality of tubular joints 23 embedded in the concrete 21. The concrete 21 has a square cross section, and the main bars 22 are vertically arranged near the corners and sides thereof. The joint 23 is vertically embedded in the lower end of the concrete 21 at a position corresponding to the main bar 22. The lower end surface of the concrete 21 has an opening 21a formed of a tapered hole.
Is formed, and the lower end of the internal space 23a of the joint 23 is opened to the lower end surface of the concrete 21 through the opening 21a.

Although the joint 23 is of a known structure and will not be described in detail, a large number of annular ribs (not shown) are formed on its inner wall surface at intervals in the axial direction. The lower end of the main bar 22 of the PC column 20 is inserted into the upper portion of the internal space 23a of the joint 23. In the vicinity of the lower end and the upper end of the joint 23, there are an inlet 23x and an outlet 2 which are continuous with the internal space 23a.
3y are formed, and these are opened to the side surface through openings 21x and 21y formed in the side surface of the concrete 21.

A method of installing the PC column 20 in the joint section 10 will be described in detail. First, as shown in FIG. 1, a plurality of spacers 15 obtained by cutting a thick iron plate are placed on a planned build-up location A on the bottom surface 13a of the recess 13 of the joint 10.

Next, the semi-hardened high-strength mortar 16 is supplied into the recess 13. The level of the mortar 16 is higher than that of the spacer 15. The mortar 16 has fluidity in a semi-hardened state, but does not flow out because it is housed in the recess 13.

After the mortar 16 is supplied to the concave portion 13, the PC column 20 is placed on the spacer 15 so that the PC pillar 20 coincides with the planned location A as shown in FIG. At this time, the upper end of the main bar 12 of the connection part 10 is PC
It enters the lower portion of the joint 23 through the opening 21 a of the column 20. As a result, the main bars 22 of the PC columns 20 and the main bars 12 of the joint section 10 face each other coaxially in the joint 23. The height of the PC column 20 is determined by the height of the upper surface of the spacer 15.

The lower end of the PC column 20 enters the recess 13 (being below the slab surface 11a), and is immersed in the mortar 16 while being mounted on the spacer 15 (while floating from the bottom surface of the recess 13). As a result, the gap between the lower end surface of the PC column 20 and the bottom surface 13a of the recess 13, that is, the joint portion,
It will be filled with mortar 16. Moreover, since the level of the mortar 16 rises and enters the opening 21a of the PC column 20, the internal spaces 23a of the plurality of joints 23 are independent from each other. A part of the mortar 16 spreads between the outer peripheral surface of the lower end of the PC column 20 and the edge surface 13b of the recess 13 to completely close the joint. The supply amount of the mortar 16 is predetermined so that the level of the mortar 16 in this state is below the slab surface 11a.

After the PC column 20 is placed on the spacer 15, the inclination and the horizontal position of the PC column 20 are adjusted (position adjustment) in a short time. At this time, since the mortar 16 is in a semi-hardened state and has fluidity, it can follow the PC column 20 whose position is adjusted, and it is possible to avoid the occurrence of joint cracks.

After the position adjustment, it is left for several hours to wait for the hardening of the mortar 16 to proceed. After that, as shown in FIG. 3, the mortar 25 is injected at a predetermined pressure from the injection port 23x of each joint 23 using an injection machine (not shown). The mortar 25 reaches the discharge port 23y after filling the internal space 23a. The mortar 25 is discharged from the worker 23
When y is reached, it is confirmed that the filling of the mortar 25 is completed, and the injection work is finished.

The injection pressure of the mortar 25 is also applied to the mortar 16 in the joint portion, but since the mortar 16 is harder than the mortar 25 at the time of injection, it does not leak to the outside from the joint portion. The hardness at the time of supplying the mortar 16 to the recess 13 and the hardness at the time of injecting the mortar 25 are
It may be about the same. Due to the hardening of the mortar 25, the main bars 12 and 22 are connected to each other via the mortar 25 and the joint 23, and the building of the PC column 20 into the joint portion 10 is completed.

In the above embodiment, since the mold is not required to be formed due to the mortar 16 having fluidity, and the mold need not be removed, the work can be simplified. Also,
Since the injection work of the mortar 25 is not performed collectively for all the joints 23 but individually, it is not necessary to check the state of the other joints 23 when the injection work for one joint 23 is performed, and skill is required. do not do.

Since the amount of mortar injected into each joint 23 is small, it is possible to prevent air entrapment and ensure a high connection strength. Also, the mortar 16 at the joint and the joint 2
Different materials can be used for the mortar 25 of No. 3 corresponding to the joint portion and the joint 23, respectively. That is, the mortar 16 in the joint portion can be made of a material having the same strength as that of the concrete 21 of the PC column 20, and the mortar 25 of the joint 23 can be made of a material having a predetermined strength and easily injected.

Further, since the concave portion 13 for accommodating the mortar 16 is defined by the base material of the concrete 11,
The adhesiveness with the mortar 16 is good, and the bonding strength between the PC column 20 and the joint portion 10 can be increased. further,
Since the lower end of the PC column 20 is inserted into the concave portion 13 of the concrete 11 of the joint portion 10, the shear strength of the joint portion can also be increased. Furthermore, the mortar 16 has a slab surface 1
Since it is not higher than 1a, it is not necessary to remove the mortar 16 at the end.

Next, another embodiment of the present invention will be described. In these other embodiments, the components corresponding to those in the first embodiment are denoted by the same reference numerals in the drawings, and the description thereof will be omitted. In the second embodiment shown in FIG. 4, in the PC column 20, the joint 23 ′ different from that of the first embodiment is the concrete 21.
Embedded in. The upper portion of this joint 23 'is a female screw portion 23z, and the inner space 23a is formed in the lower portion. The lower end portion of the main bar 22 made of a screw rebar is connected to the female screw part 23z of the joint 23 'by screwing. The upper end portion of the main bar 12 of the connection part 10 is connected to the joint 23 via the injection mortar 25 as in the first embodiment, and is further connected to the main bar 22. Each step of the building method is the first
The description is omitted because it is the same as the embodiment.

In the third embodiment shown in FIG. 5, the slab surface 1
1a is flat and does not have a recess as in the first and second embodiments. Instead, the planned location A
A frame 30 is provided so as to surround the. Either the frame 30 or the spacer 15 may be installed first. Frame 3
The inner peripheral surface of 0 and the slab surface 11a define a housing portion 13 '. The area of the accommodating portion 13 'is larger than the planned construction area A. After that, the supply of the mortar 16, the installation of the PC column 20, the position adjustment, and the injection of the mortar 25 are performed as in the first embodiment. Since the frame 30 is separated from the place where the PC pillar 20 is to be built, no skill is required for its installation work.
In this embodiment, the mortar 16 around the PC column 20 is finally removed.

The present invention is not limited to the above embodiment, and various forms can be adopted. For example, the PC vertical member may be a wall panel. In this case, the lower structure is the joint between the floor slab and the wall panel. The mortar supplied to the accommodating portion of the lower structure may be harder than the semi-cured state of the first embodiment, or may be softened to increase the fluidity. The point is that it should be soft enough not to cause joint cracks when adjusting the position of the vertical member, and should be harder than this injected mortar when injecting mortar into the joint.

It is preferable that the spacer installation work at the planned installation location precedes the mortar supply work to the accommodating portion, but the order of both may be reversed. The spacer may be hard-coated mortar in the shape of a dumpling. The same kind of mortar may be used for the joint mortar and the joint mortar.

[0031]

As described above, according to the first aspect of the present invention, when the position of the vertical member is adjusted, since the mortar in the joint portion has fluidity, joint cracking is prevented. It can be avoided. Further, since the mortar in the joint is harder than the injected mortar when the mortar is injected into the joint, it does not leak out from the joint. Further, since it is not necessary to install the formwork so as to close the joint portion, the installation work can be simplified. Further, since the mortar injection into the joint is not performed all at once but individually, it is not necessary to check the state of the other joints during the injection work into one joint, and no skill is required.

According to the second aspect of the present invention, the work of installing and removing the mold for the mortar is completely unnecessary, and the work can be further simplified. According to the third aspect of the present invention, since the concave portion that accommodates the mortar is defined by the concrete body, the adhesiveness with the mortar is good and the joint strength can be increased. According to the fourth aspect of the present invention, a mold is used for the joint mortar, but this mold does not close the joint and is away from the planned site of construction, so that no skill is required for installation work. . According to the fifth aspect of the present invention, the mortar does not project from the upper surface of the lower component, and the work of removing the mortar can be omitted.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an initial stage in a method of building a PC column according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view showing the next step of the method.

FIG. 3 is a vertical sectional view showing a final step of the method.

FIG. 4 is a vertical cross-sectional view showing a method of building a PC column according to a second embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view showing a method of building a PC column, which constitutes a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Joint part (lower structure part) 11 Concrete 12 Main bar 13 Recessed part (accommodation part) 13 'Storage part 15 Spacer 16 Mortar 20 PC pillar (vertical member made of precast concrete) 21 Concrete 22 Main bar 23, 23' Joint 23a Internal space 23x inlet 23y outlet 25 mortar 30 frame A

Claims (5)

[Claims] 1. A method of building a vertical member made of precast concrete in a concrete lower structure part, wherein the vertical member is embedded in a lower end portion of concrete and an internal space is opened to a lower end surface of the concrete. A plurality of tubular joints, and a plurality of main bars that are embedded in concrete and extend vertically and the lower end is inserted or connected to the upper part of the joint, and the joint has an inlet and an outlet above it. The inlet and outlet are open to the side surface of the concrete, and the lower structural part is formed by vertically projecting a plurality of main bars from a planned construction site on the upper surface of the concrete. On the upper surface of the vertical member, a housing part having a larger area than the planned installation site of the vertical member and an open upper part is provided, and a spacer is placed at the planned installation site. Mortality is accommodated in the accommodating portion to a level exceeding the spacer, and (b) the main bar of the lower structural portion is inserted into the lower portion of the joint of the vertical member, and the vertical member is erected in the lower structural portion via the spacer. Placed in a place to be embedded, thereby making the inner spaces of the plurality of joints independent from each other in the mortar housed in the housing part, and spreading the mortar between the lower end outer circumference of the vertical member and the housing part peripheral edge,
(C) Adjusting the position of the vertical member placed on the above-mentioned built-in location, (d) filling the internal space by injecting mortar from each injection port of the above independent joint, and hardening the mortar, The vertical member and the main bars of the lower structure portion are connected to each other via a mortar and a joint, and the mortar housed in the housing portion of the lower structure portion can avoid at least joint breakage when adjusting the position of the vertical member. A method for building a vertical member made of precast concrete, which is moderately soft and has fluidity, and is harder than the injected mortar when pouring mortar into the joint. 2. The method for building a vertical member made of precast concrete according to claim 1, wherein the accommodating portion is recessed from the upper surface of the lower structure portion. 3. The housing portion is partitioned by a concrete base material of the lower structure portion.
The method for building a vertical member made of precast concrete according to 1. 4. The accommodating portion of the lower structure portion is defined by an upper surface of concrete of the lower structure portion and a separate formwork placed thereon. How to build vertical members made of precast concrete. 5. The amount of mortar supplied to the accommodating portion is determined such that the level of the mortar increased by placing the vertical member on the spacer is equal to or shallower than the depth of the accommodating portion. The method for building a vertical member made of precast concrete according to any one of claims 1 to 4, which is characterized in that.