JPH09203117A - Joining method of centrifugally formed concrete filled steel pipe column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate joining of centrifugally formed concrete filled steel pipe columns having longitudinally continuous cavity parts inside. SOLUTION: A column 10 is provided with a hardened concrete body 12 inside a steel pipe 11, and a cavity part 13 to be formed during the centrifugal forming. An end face of the hardened body 12 is formed in a recessed manner from each side edge of the steel pipe 11. The columns 10 are butted in the vertical direction and temporarily attached. In the lower column 10, a plate body 18 is arranged on an upper end face of the hardened body 12 to cover an opening of the cavity part 13. Then, the steel pipes 11 are welded to each other. The mortar M is poured between the hardened bodies 12. Because the opening of the lower cavity part 13 is covered by the plate body 18, the mortar M does not flow into the cavity 12. Because the plate body 18 is loaded on the hardened body 12, it is not moved downward or dropped into the cavity part 13 by the pouring pressure or the load of the mortar M.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining centrifugally-molded concrete-filled steel tubular columns for vertically joining the centrifugally-molded concrete-filled steel tubular columns suitably used for construction and civil engineering structures.

[0002]

2. Description of the Related Art In recent years, there has been provided a centrifugally-molded concrete-filled steel pipe column in which concrete is filled into a steel pipe and the whole pipe is rotated at a high speed around its central axis to centrifugally mold the filled concrete. In such concrete columns, since the filled concrete is compacted and strengthened by a simple centrifugal molding operation, reinforcing bars are embedded in the hardened concrete and steel wires, steel rods, etc. are put in the hardened concrete. It is possible to easily and economically increase the yield strength of the hardened concrete without applying prestress.

By the way, in order to construct an architectural or civil engineering structure using such concrete columns, there is a limit to the length of the concrete columns in terms of manufacturing or transportation. Is usually used. In order to join such concrete columns, the concrete columns are temporarily fixed in a state of being abutted against each other, welded between the steel pipe edges, and then the mortar is filled with concrete from the mortar filling hole formed in the steel pipe edges. A possible method is to fill the space between the end faces of the cured body and then connect the cured body by curing it. However,
In the joining method as described above, when the mortar is filled between the end surfaces of the hardened concrete, the mortar flows down into the cavity of the hardened concrete, so that the mortar is filled more than necessary, which is uneconomical. In addition, it is difficult to confirm whether or not the mortar is reliably filled between the end faces of the cured body, which is not practical.

As a technique for solving such inconvenience,
For example, there is a technique shown in FIG. In this technique, the sheath tube 3 is inserted into the hollow portion 2 of the lower concrete column 1a,
Further, the upper concrete pillar 1b is erected on the concrete pillar 1a in a state of being abutted, and the end faces of the steel pipes 4, 4 on the abutting sides are welded to each other. To mortar M
Is a method of injecting. Reference numeral 7 is an air vent hole for letting air between the concrete hardened bodies 5, 5 escape when the mortar M is injected from the mortar injection hole 6.

As another technique for solving the above-mentioned inconvenience, there is a technique shown in FIG. 5, for example. This technology is
The filling material 8 is filled in the cavity 2 of the lower concrete column 1a, and the upper concrete column 1b is erected on the concrete column 1a in a state of being abutted, and the steel pipes 4 and 4 on the respective abutting sides are placed. After welding between the end faces, the mortar injection hole 6 is provided between the hardened concrete bodies 5, 5.
The method is to inject mortar M from. In addition,
In the description of FIG. 5, constituent elements that are substantially the same as the constituent elements of FIG. 4 have been assigned the same reference numerals.

[0006]

By the way, in the joining method shown in FIG. 4, in order to prevent the mortar M from leaking into the cavity 2, the sheath tube 3 has no gap and the inner surface of the cavity 2 does not have a gap. Must be in contact with. However, since the hollow portion 2 is generated during centrifugal molding and is not formed in contact with the surface of the mold or the like, the hollow portion 2 is not always a perfect circle, and the individual concrete The pillars 1a and 1b may have slightly different shapes. Therefore, the sheath tube 3
Even if the molding is performed with high accuracy in advance, when the sheath pipe 3 is inserted into the hollow portion 2 of the concrete column 1a, the sheath pipe 3 and the hollow portion 2
There is a possibility that a gap may be formed between the inner surface of the hollow tube 2 and the inner surface of the hollow tube 2, or the sheath tube 3 may not be properly inserted into the cavity 2.

That is, it is difficult to prepare in advance a sheath tube 3 which can be inserted into the hollow portion 2 without a gap. And
In order to insert the sheath tube 3 into the hollow portion 2 without a gap, the diameter of the sheath tube 3 is formed to be slightly larger than the diameter of the hollow portion 2 in advance, and the sheath tube 3 is ground on-site so that the sheath tube 3 is hollow. It is necessary to take measures such as processing so that it fits into the portion 2 or polishing the inner surface of the cavity 2 within an allowable range so that the sheath tube 3 fits into the cavity 2 properly. It becomes complicated.

If a flexible member or an elastically deformable member is used as the sheath tube 3, it is possible to deal with the cavity 2 having a somewhat different shape without polishing the sheath tube 3 on site. However, if the shape of the cavity 2 is further different, the sheath tube 3 also needs to be processed on site. Further, if the sheath pipe 3 is simply inserted into the hollow portion 2, the sheath pipe 3 may move downward from the joint between the concrete columns 1a and 1b, and if the sheath pipe 3 moves downward, ,
The injected mortar M may be exposed inside the cavity 2.

Also in the joining method shown in FIG. 5, in order to prevent the filler 8 from leaking the mortar M into the cavity 2, the filler 8 must be in contact with the inner surface of the cavity 2 without any gap. There is. It should be noted that as the material of the filler 8, a material such as rubber or rock wool that can be easily processed is assumed, but again, it is necessary to process each material in accordance with the shape of the cavity 2, which is troublesome. Further, in the joining method shown in FIG. 5, as can be seen from FIG. 5, since the mortar M is injected onto the filler 8 filled in the cavity 2, the injection pressure of the mortar M and the mortar M are increased. The load 8 presses the filling 8 downward, and the filling 8 is more likely to move downward than the sheath tube 3 shown in FIG. 4 and falls into the cavity 2. There is also the possibility of doing it.

When the filling 8 moves downward, the filling 8 at the joint portion between the concrete columns 1a and 1b.
Since the upper space is increased, it is impossible to know how much mortar should be injected to completely fill the mortar M between the upper and lower concrete hardened bodies 5 and 5 at the joint.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a centrifugally-molded concrete-filled steel tubular column capable of reliably filling mortar between the end faces of a hardened concrete body by an extremely simple operation. To provide a joining method.

[0012]

In the method for joining centrifugally-molded concrete-filled steel pipe columns according to claim 1 of the present invention, a steel pipe has a centrifugally-molded concrete hardened body, and the centrifugally-molded concrete hardened body has a hardened body. Centrifugal-molded concrete-filled steel pipe columns obtained by leaving a hollow portion in the axial direction of the steel pipe formed during centrifugal molding are connected to each other by abutting against each other. Prepared ones whose both end surfaces are respectively formed by entering from both end edges of the steel pipe, and then the centrifugally molded concrete-filled steel pipe arranged below the centrifugally-molded concrete-filled steel pipe columns to be joined to each other vertically. In the pillar, a plate is placed on the upper end surface of the centrifugally molded concrete body so as to close the upper end opening of the cavity. In addition, the centrifugally-molded concrete-filled steel pipe columns are temporarily fixed to each other in a state of being abutted on each other, and then the steel pipes of the vertically-cast agitated concrete-filled steel pipe columns are welded together. Injecting mortar between the end faces of the respective centrifugally-molded concrete hardened bodies was used as a means for solving the above problems.

According to the above construction, the centrifugally-molded concrete-filled steel pipe columns to be joined vertically are arranged with the plate body arranged on the upper end surface of the centrifugally-molded concrete hardened body so as to close the upper end opening of the cavity. Since mortar is injected between the centrifugally-molded concrete hardened bodies, it is possible to reliably prevent the injected mortar from leaking into the cavity.

When the plate is placed on the upper end surface of the centrifugally hardened concrete of the lower centrifugally-molded concrete-filled steel tubular column, when pressure or load is applied to the mortar on the plate. Moreover, the plate body does not move downward in the cavity or fall. vice versa,
By applying pressure or load on the plate body, the plate body is pressed against the upper end surface of the hardened centrifugally molded concrete, preventing a gap between the plate body and the hardened centrifugally molded concrete can do.

Further, as a work for preventing the mortar from leaking into the cavity, the plate body is simply placed on the upper end surface of the hardened centrifugally molded concrete, and it is extremely easy to join the steel tube columns filled with the centrifugally molded concrete. You can Further, the plate body basically has a shape that can be inserted into the steel pipe and can close the opening of the hollow portion, and can be manufactured extremely easily.

Further, in a building, a compression force is mainly applied to the columns, but if the plate body has a sufficient bearing strength, it is not possible to transmit the compression force at the joint between the columns. There is no problem, and it is possible to secure the necessary and sufficient strength as a pillar. When injecting mortar, injection holes may be provided at the joints of the steel pipes of the centrifugally-molded concrete-filled steel pipe columns to be joined in the same manner as in the conventional example, or the centrifugally-molded concrete-filled steel pipes arranged on the upper side. An injection pipe or the like may be inserted from the upper opening side of the pillar.

The plate may be of any type as long as it has sufficient bearing strength as described above. For example, a metal plate such as a steel plate, a precast concrete plate,
A high strength synthetic resin plate or the like can be used. Further, when the plate body bends during mortar injection, the required injection amount of mortar in the joint may change, so the plate body does not bend significantly due to pressure or load during injection of the mortar, that is, , Must have high rigidity.

Further, as the material constituting the centrifugally cast concrete-filled steel tube column such as the centrifugally cast concrete hardened body, the steel pipe, and the mortar, and the material necessary for joining other than the plate body, the same materials as those in the conventional art can be used. The material is not particularly limited, and known materials can be used.

In the method of joining a centrifugally-molded concrete-filled steel pipe column according to a second aspect of the present invention, the front-rear, left-right width of the plate is smaller than the front-rear, left-right inner width of the steel pipe, and at least the plate is The means for solving the above-mentioned problems is that one side edge has a length such that the other side edge portion is in a state of completely covering the opening of the cavity while the one side edge is in contact with the inner surface of the steel pipe.

According to the above construction, when the plate body is arranged on the upper end surface of the centrifugally-molded concrete hardened body so as to close the upper end opening of the hollow portion, mortar is injected even if the plate body is displaced. In this case, the mortar does not flow into the cavity. That is, since the upper end surface of the hardened centrifugally molded concrete is in a state of being surrounded by the steel pipe, the placed plate body cannot move to the outside of the steel pipe, and one side edge of the plate body contacts the inner surface of the steel pipe. At that stage, the plate cannot move any further. In this state, if the other side edge portion of the plate body covers the opening of the cavity, the mortar will not flow into the cavity even if the position of the plate body deviates to the maximum.

Even if the plates are displaced, if the space between the hardened centrifugally molded concrete is filled with the mortar and the plates without a gap, sufficient compression force can be transmitted as described above. It is possible and there is no problem in the strength of the pillar.
In addition, if the shape of the plate corresponds to the cross-sectional shape of the inside of the steel pipe and is slightly smaller than the above-mentioned cross-sectional shape, the position where the plate is arranged does not shift, and it is necessary to pay attention to the installation of the plate. Therefore, the plate body can be easily installed.

If the shape of the plate body corresponds to the cross-sectional shape of the inside of the steel pipe and is slightly smaller than the above-mentioned cross-sectional shape, most of the injected mortar is filled in the plate body. Since the plate body can be pressed against the upper end surface of the hardened concrete by the load of the mortar, the mortar can be reliably prevented from flowing into the cavity. Furthermore, since most of the mortar injected as described above is filled on the plate body, the mortar injected around the plate body does not wrap around and push up the plate body by buoyancy or the like. It is possible to reliably prevent the mortar from flowing into the cavity.

In the method for joining centrifugally-molded concrete-filled steel tubular columns according to claim 3 of the present invention, when the plate body is arranged on the upper end surface of the centrifugally-molded concrete hardened body, the plate body and the centrifugally-molded concrete hardened body are joined together. Pressing the plate body against the centrifugally hardened concrete with the mortar thinly sandwiched between them was the means for solving the above problems.

According to the above construction, the plate body and the centrifugally-molded concrete hardened body are brought into close contact with each other by the mortar, and the plate-like body is obtained even if the upper end surface of the centrifugally-molded concrete hardened body is not in a smooth state. It is possible to prevent a gap from being generated between the centrifugally-molded concrete hardened body and the hardened body. Therefore, when the upper end surface of the centrifugal molded concrete hardened body is not smooth, a gap is generated between the plate body and the centrifugal molded concrete hardened body, and it is possible to prevent mortar from leaking from the gap, The gap can surely prevent the transmission of the above-mentioned compression force from being hindered.

Further, when the plate and the hardened centrifugally molded concrete are brought into close contact with each other by mortar, the plate does not shift even if a slight external force is applied to the plate, and the plate is displaced. Thereby, it is possible to prevent the mortar from flowing out. Further, when the mortar is injected around the plate body at the time of mortar injection, even if a force such as buoyancy that pushes up the plate body is applied, the plate body and the centrifugally-molded concrete hardened body are mortar-like as described above. Since they are in close contact with each other, it is possible to prevent the plate body from rising and the mortar from flowing out.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for joining centrifugally-molded concrete-filled steel tubular columns according to the present invention will be described in detail below with reference to the drawings. First, a centrifugally-molded concrete-filled steel tubular column (hereinafter abbreviated as a concrete column) 10 as shown in FIG. 1 is prepared. The concrete pillar 10 is composed of a square steel pipe 11 and a concrete hardened body 12 provided inside the steel pipe 11. The concrete hardened body 12 is formed by centrifugal molding, whereby the concrete pipe 10 is formed in the axial direction of the steel pipe 11. The hollow portion 13 formed along is left as it is. The steel pipe 11 has a taper portion 14 for welding formed on one edge thereof (edge on the lower end side when standing upright). The hardened concrete body 12 is formed such that both end surfaces thereof enter from both end edges of the steel pipe 11, respectively, whereby mortar filling portions 15 (spaces filled with mortar) are formed at both end portions of the concrete column 10. There is. In addition, the concrete hardened body 12
The length where both end faces of the steel pipe 11 enter from the both end edges of the steel pipe 11 is a length that can avoid the thermal influence when welding between the steel pipes 11 as described later, and thus the mortar filling portion 15 is It also has the function of avoiding the influence of heat during welding. Further, when the steel pipes 11 and 11 are welded to each other, the steel pipes 11 and 11 contract slightly, but by providing the mortar filling portion 15, the concrete hardened bodies 12 and 12 in the steel pipes 11 and 11 are provided. Are not in direct contact with each other.
A contraction amount of 1 can be absorbed.

In order to manufacture such a concrete pillar 10, a conventionally well-known centrifugal molding method can be adopted.
That is, the steel pipe 11 is inserted into a cylindrical (cylindrical) rotary body having an appropriate through-hole for externally inserting the steel pipe 11, and the steel pipe 11 is filled with concrete before hardening. A method of supporting a roller of a known centrifugal force molding machine and rotating the roller at a high speed to perform centrifugal molding, or fixing both ends of the steel pipe 11 to a rotating body and rotating the rotating body at a high speed to perform centrifugal molding. The method of doing is adopted.

To carry out such a centrifugal molding method, first,
As shown in FIG. 2, both ends of the steel pipe 11 are closed with a mold 16 having a predetermined thickness, that is, a thickness corresponding to a length capable of avoiding a thermal effect at the time of welding between the steel pipes 11, 11. Fill a predetermined amount of green concrete. The formwork 16 is provided with a fresh concrete inlet and a hole (not shown) that serves as a dehydration path from the fresh concrete. Further, the steel pipe 11 is preliminarily formed with a hole 17 for injecting mortar at one end thereof. The formation position of the hole 17 is, of course, on the end edge side of the steel pipe 11 with respect to the end surface of the hardened concrete body 12 to be formed.

Next, the steel pipe 11 is rotated around its axis at a high speed, the filled concrete is centrifugally molded, and the concrete is cured and cured to obtain the concrete column 10 shown in FIG. Then, in order to connect and join the concrete columns 10 obtained in this way, first, as shown by the chain double-dashed line in FIG. It is arranged on the upper end surface of 12 to close the opening of the cavity 13. The plate member 18 has sufficient bearing strength and has a mortar (see FIG. 3).
A material having a rigidity that does not bend when filled with M) is preferably used, and specifically, a steel plate, a precast concrete plate, a high-strength synthetic resin plate, or the like is used.

The shape of the plate 18 is substantially equal to the cross-sectional shape of the inside of the steel pipe 11, and is slightly smaller than the cross-sectional shape of the inside of the steel pipe 11 so that it can be easily arranged in the steel pipe 11. It is small. Since the plate body 18 substantially covers the upper end surface of the hardened concrete body 12 due to the above-described shape of the plate body,
When the injection of the mortar M from the injection hole 17 is started, most of the mortar M is placed on the plate 18, and the load of the mortar M is applied to the plate 18. Therefore, the mortar M does not wrap around to the side edge of the outer periphery of the plate body 18 and push up the plate body 18 due to buoyancy or the like, and it is possible to reliably prevent the mortar M from flowing into the cavity 13. .

Further, due to the above-described shape of the plate body 18, the plate body is in a state of substantially being fitted inside the steel pipe 11, and the plate body can hardly be moved left and right and front and rear. It is possible to reliably prevent the mortar M from flowing into the cavity 13 without shifting from the opening of the cavity 13. The shape of the plate body 18 is not necessarily limited to the above shape, and may be any size that can be inserted into the steel pipe 11 and that can close the opening of the cavity 13. .

However, if the size of the plate body 18 is small, when the position of the plate body 18 is deviated, the opening of the cavity 13 is opened in the plate body 1.
8 can no longer be covered, the mortar M in the cavity 13
Since there is a possibility that the plate body 18 will flow in, the width (diameter of the plate body 18) of the plate body 18 on the left, right, front and rear is shorter than the inner width of the steel pipe 11,
In addition, at least one side edge of the plate body 18 has the steel pipe 11
It is preferable that the other side edge portion be in a state of completely covering the opening of the hollow portion 13 while being in contact with the inner surface.

The upper end surface of the hardened concrete body 12 is a smooth flat surface when the mold 16 having sufficient rigidity is used, and when the flat body 18 is placed, the hardened body 18 and the hardened concrete body are It is unlikely that there will be a gap between the upper end surface of 12.

However, if there is a possibility that a gap will occur between the plate body 18 and the upper end surface of the concrete hardened body 12, there will be a gap between the plate body 18 and the upper end surface of the concrete hardened body 12. In order to reliably prevent the occurrence of the above, when arranging the plate body 18 on the upper end surface of the concrete hardening body 12, for example, by applying mortar to the upper end surface of the concrete hardening body 12, the plate body 18 and the concrete hardening body It is preferable that the mortar is thinly sandwiched between the upper end surface of the body 12 and the plate body 18 is pressed against the hardened concrete body 12.

By arranging the plate body 18 in this manner, the plate body 1
8 adheres to the upper end surface of the hardened concrete body 12, and the plate body 1
8 and the upper end surface of the concrete hardened body 12 can be reliably prevented from occurring, and even if the shape of the plate body 18 is smaller than the inner diameter of the steel pipe 11, the plate body 18 moves so as to shift. It is possible to prevent the plate body 18
Can be prevented from being pushed up by buoyancy or the like when the mortar M is injected.

The plate member 18 has a shape, for example,
Even if it is made to match the inner cross-sectional shape of the steel pipe 11 as described above, there is no need to process the steel pipe 11 into an accurate shape, and it is easy to mold it if it has a shape that can be put into the steel pipe 11. You can In addition, since it is not necessary to form the plate body 18 in accordance with the inner cross-sectional shape of the steel pipe 11 accurately, if the plate body 18 is formed in advance in the steel pipe 11 with a small size, the plate body 18 is formed in the steel pipe 11. When arranging the body 18, there was a slight error in the shape of the plate body 18,
There is no possibility that the plate body 18 cannot be inserted into the steel pipe 11, and there is no possibility that the plate body 18 is inserted into the steel pipe 11 by making modifications such as cutting the plate body 18 on site. . The plate 18 is arranged on the upper end side of the lower steel pipe 11, in this example, on the opposite side of the mortar injection hole 17 previously formed in the steel pipe 11.

Next, as shown in FIG. 3, the concrete pillar 10 is erected with the side on which the plate 18 is arranged facing upward, and another concrete pillar 10 is further laid on the concrete pillar 10, the lower end portion of which and the concrete pillar. Stand so that the upper ends of 10 are butted against each other. In addition, the lower concrete pillar 1
The plate 18 may be arranged after 0 is set.

Next, these concrete columns 10, 10
The steel pipes 11 and 11 are temporarily fixed on each surface by four temporary fixing members 19. The temporary fixing member 19 is a conventionally known member, and is a plate member 19a, 19a attached to the end portion of each of the steel pipes 11, 11 on the joining side, and these plate members 19
Connecting plate 19b for connecting a and 19a with bolts
It consists of: The plate member 19a is formed with a notch 19c at the end of the steel pipe 11 on the side where the steel pipes are abutted, so that a gap is formed between the plate member 19a and the steel pipe 11, and the temporary fixing member 19 is formed by the notch 19c. Welding between the steel pipes 11, 11 can be performed also in the disposed portion.

Next, the steel pipes 11 and 11 at the joint portion
The gap is welded by utilizing the taper portion formed on the edge of the steel pipe 11. At this time, since the end surface of the hardened concrete body 12 is spaced from the welded portion, that is, the edge of the steel pipe 11 by a distance not affected by heat, it is not adversely affected by heat generated by welding. After that, temporary fixing material 1
9 is removed, and the steel pipe 11 of the concrete pillar 10 on the upper side is further removed.
From the mortar injection hole 17 formed in the
Inject.

In this case, the mortar-filled portion, that is, the volume of the mortar-filled portions 15, 15 of the concrete columns 10, 10 is calculated in advance, and the amount of mortar slightly larger than the amount corresponding to this volume is calculated. Inject M. Then, since the plate member 18 is arranged on the upper end opening of the hollow portion 13 of the lower concrete pillar 10 and the hollow portion 13 is closed, the injected mortar M is the hollow portion of the lower concrete pillar 10. It does not flow down into 13 and fills the mortar filled portion.

Further, the mortar-filled portion communicates with the cavity 13 of the upper concrete column 10, and the cavity of the upper concrete column 10 is open to the atmosphere, so that no air vent hole is required. Then, a predetermined amount of mortar M is injected, and when a part of the mortar M rises into the cavity 13 of the upper concrete column 10 in calculation as shown in FIG. 3, the injection of the mortar M is finished, Mortar M injected by closing the injection hole 17 with a plug or the like
Curing and curing, which completes the bond.

The concrete columns 10 and 10 can be joined not only between the two columns shown in FIG. 3 but also between a large number of concrete columns 10 and 10 by the same method. The plate body 18 may be arranged on the upper end of the cavity 13 of the concrete pillar 10 which is newly located below, and the plates 18 may be sequentially joined in the same manner as described above. And
Concrete columns 10 and 10 joined in this way
The pillars are fireproofed by sticking or spraying a fireproof coating on them. The fireproof coating material is made of a material that is lightweight and has excellent fireproof performance, such as gypsum board, various chemical boards, mats and spraying materials. The fireproof coating material may be pasted or sprayed on the outer peripheral surface of the steel pipe 11 in a factory after the hardened concrete 12 is centrifugally molded.

In such a joining method between the concrete columns, since the cavity 13 is closed by the plate body 18, the injected mortar does not flow down into the cavity 13, and therefore the injected mortar is prevented. Can be reliably filled between the end surfaces of the hardened concrete body 12. In addition, since the mortar can be reliably filled in this way, the volume between the end faces of the concrete hardening body 12 is calculated in advance, and the mortar injection amount is controlled based on this calculated amount. Can be reliably filled with mortar. In the above embodiment, the steel pipe 11 has a square shape, but other shapes such as a circular shape, a triangular shape, a pentagonal shape or more, and an oval shape may be used.

[0044]

As described above, according to the method for joining centrifugally-molded concrete-filled steel pipe columns according to the first aspect of the present invention, the upper-end surface of the hardened centrifugally-cast concrete blocks the upper end opening of the cavity. Since the mortar is injected between the centrifugally hardened concrete-filled steel tube columns that are joined to each other in the state where the plate body is placed in the space, the injected mortar leaks into the cavity. Can be reliably prevented.

Further, when the plate body is placed on the upper end surface of the centrifugally hardened concrete-hardened body of the lower centrifugally-molded concrete-filled steel tubular column, pressure or load is applied when the mortar is filled on the plate body. Moreover, the plate body does not move downward in the cavity or fall. vice versa,
By applying pressure or load on the plate body, the plate body is in a state of being pressed against the upper end surface of the centrifugally molded concrete hardened body, and prevents a gap from being formed between the centrifugally molded concrete hardened body and the plate body. can do.

Further, as a work for preventing the mortar from leaking into the cavity, the plate body is simply placed on the upper end surface of the hardened centrifugally molded concrete, and it is extremely easy to join the steel tube columns filled with the centrifugally molded concrete. You can Further, the plate body basically has a shape that can be inserted into the steel pipe and can close the opening of the hollow portion, and can be manufactured extremely easily. In addition, in a building,
Although a compressive force is mainly applied, if the plate has sufficient bearing strength, there will be no problem in transmitting the compressive force at the joint between the columns, and the necessary and sufficient strength for the columns will be secured. be able to.

According to the method for joining centrifugally-molded concrete-filled steel tube columns according to claim 2 of the present invention, when a plate body is arranged on the upper end face of the centrifugally-molded concrete hardened body so as to close the upper end opening of the cavity. Moreover, even if the plate body is displaced, when the mortar is injected, the mortar does not flow into the cavity. That is, since the upper end surface of the centrifugally molded concrete hardened body is covered with the steel pipe, the arranged plate body cannot move to the outside of the steel pipe, and one side edge of the plate body contacts the steel pipe. Therefore, the position of the plate does not shift further. In this state, if the side edge portion of the plate body covers the opening of the hollow portion, the mortar will not flow into the hollow portion.

Even if the plates are displaced, if the space between the centrifugally-molded concrete hardened bodies is filled with the mortar and the plates without a gap, sufficient compression force can be transmitted as described above. It is possible and there is no problem in the strength of the pillar.
Also, if the shape of the plate body corresponds to the cross-sectional shape of the inside of the steel pipe and is slightly smaller than the above-mentioned cross-sectional shape, the position of the plate body does not shift and the plate body can be easily installed. Can be

Further, if the shape of the plate body corresponds to the cross-sectional shape inside the steel pipe and is slightly smaller than the above-mentioned cross-sectional shape, most of the injected mortar will be filled in the plate body. Since the plate body can be pressed against the upper end surface of the hardened concrete by the load of the mortar, the mortar can be reliably prevented from flowing into the cavity. Furthermore, since most of the mortar injected as described above is filled on the plate body, the mortar injected around the plate body does not wrap around and push up the plate body by buoyancy or the like. It is possible to reliably prevent the mortar from flowing into the cavity.

According to the method for joining centrifugally-molded concrete-filled steel tubular columns according to claim 3 of the present invention, the plate body and the centrifugally-molded concrete hardened body are brought into close contact with each other by mortar, and the centrifugally-molded concrete hardened body Even if the upper end surface is not in a smooth state, it is possible to prevent a gap from being formed between the plate body and the centrifugally molded concrete hardened body. Therefore, when the upper end surface of the centrifugal molded concrete hardened body is not smooth, a gap is generated between the plate body and the centrifugal molded concrete hardened body, and it is possible to prevent mortar from flowing out from the gap, It is possible to prevent the transmission of the compressive force from being hindered by the gap.

Further, when the plate and the hardened centrifugally molded concrete are brought into close contact with each other by mortar, the plate does not shift even if a slight external force is applied to the plate, and the plate is displaced. Thereby, it is possible to prevent the mortar from flowing out. Further, when the mortar is injected around the plate body at the time of mortar injection, even if a force such as buoyancy that pushes up the plate body is applied, the plate body and the centrifugally-molded concrete hardened body are mortar-like as described above. Since they are brought into close contact with each other, the plate body does not float up, and the mortar can be prevented from flowing out.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of a centrifugally-molded concrete-filled steel tubular column used in the present invention.

FIG. 2 is a vertical cross-sectional view for explaining a method for manufacturing the centrifugally-molded concrete-filled steel tubular column shown in FIG.

FIG. 3 is a sectional view of an essential part showing a joint structure between centrifugally-molded concrete-filled steel pipe columns obtained by the joining method of the present invention.

FIG. 4 is a cross-sectional view of essential parts showing an example of a conventional joint structure between centrifugally-molded concrete-filled steel pipe columns.

FIG. 5 is a sectional view of an essential part showing an example of a conventional joint structure between centrifugally-filled concrete-filled steel tubular columns.

[Explanation of symbols]

 10 Centrifugal-molded concrete-filled steel pipe columns 11 Steel pipes 12 Hardened concrete 13 Cavities 18 Plates

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shigeru Yoshino 2-10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd. (72) Satoshi Miyaki 2--10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd. (72) Inventor Katsumi Naka Naka 2-10-10 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd.

Claims (3)

[Claims] 1. A centrifugally-formed concrete-filled steel pipe having a centrifugally-formed concrete hardened body inside a steel pipe, and leaving a hollow portion in the axial direction of the steel pipe formed at the time of the centrifugally-formed concrete hardened body. A method for joining centrifugally-molded concrete-filled steel pipe columns in which columns are butted and connected to each other, wherein both ends of the centrifugally-molded concrete-hardened body inside the steel pipe enter from both end edges of the steel pipe as the centrifugally-molded concrete-filled steel pipe columns. Then, in the centrifugally-molded concrete-filled steel tubular columns arranged below the centrifugally-molded concrete-filled steel tubular columns joined to each other, the upper end surface of the centrifugally-cast concrete hardened body The plate body so as to close the upper end opening of the hollow part, and the centrifugal molding concrete filling. After temporarily fixing the steel pipe columns to each other in a state of being abutted on each other, and then welding the steel pipes of the centrifugally molded concrete-filled steel pipe columns that are abutted to each other, the centrifugally molded concrete-hardened body of each of these centrifugally-molded concrete-filled steel pipe columns A method for joining centrifugally-molded concrete-filled steel pipe columns, characterized by injecting mortar between the end faces of the. 2. The front-rear, left-right width of the plate body is smaller than the front-rear, left-right inner width of the steel pipe, and at least one side edge of the plate body is in contact with the inner surface of the steel pipe, and the other side edge part But,
The method for joining centrifugally-molded concrete-filled steel tubular columns according to claim 1, wherein the method has a length such that the opening of the cavity is completely covered. 3. When the plate body is placed on the upper end surface of the centrifugally-molded concrete hardened body, the plate body is centrifugally-molded with a thin mortar sandwiched between the plate body and the centrifugally-molded concrete hardened body. The method for joining centrifugally-molded concrete-filled steel pipe columns according to claim 1 or 2, wherein the method is to press the hardened concrete.