JPH03172440A - Filled steel pipe type concrete pillar - Google Patents

Abstract

PURPOSE:To facilitate site works and provide fine finish by laying a covering concrete consisting of PC concrete previously on the periphery of a steel pipe with buffer layers interposed, and pouring concrete into the pipe while it serves as a form. CONSTITUTION:Covering concrete 7, 7 consisting of PC concrete is previously laid on the peripheries of steel pipes 6, 6 with buffer layers 8, 8 interposed. These steel pipes 6, 6 are carried to the construction site and filled with concrete to accomplish a concrete pillar of filled steel pipe type. This greatly reduces site works such as assembly, dismantlement, etc., of the form, and also provides a fine finished condition.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a filled steel pipe concrete column in which the outer peripheral surface of the steel pipe is covered with concrete.

``Prior art'' A filled steel pipe concrete column, which is made by placing concrete inside a steel pipe, can absorb the compressive force acting in the axial direction with concrete that has a strong compressive strength, and can also withstand the compression of 1 inch to 1 inch. By suppressing radial expansion using the steel tube's confining effect (circumferential tightening is stress), a column member with high axial force can be realized.

By the way, if the steel pipes of such filled steel pipe concrete columns are exposed to the outside, in the event of a fire, etc., the steel pipes will be heated directly, which may cause the steel pipes to soften and cause the column to collapse. be.

Therefore, it may be required in the design to provide a fire-resistant covering such as concrete on the surface of this steel pipe.Also, if the steel pipe is exposed, it may be undesirable for damage protection or appearance. In such cases as well, a covering with concrete, mortar, etc. is applied.

Covering concrete such as fireproof coating is usually made by setting a formwork around the steel pipe with a certain gap, and pouring concrete etc. into the gap between the formwork and the steel pipe.
Alternatively, it can be formed by stretching a lath around the outer periphery of a steel pipe and plastering it with mortar.

``Problem to be Solved by the Invention'' However, as mentioned above, in the case of coating concrete such as fireproof coating, a formwork is provided around the steel pipe with a predetermined gap between the steel pipe and the concrete is placed in the gap between the formwork and the steel pipe. Since it is formed by casting, there is a problem in that it takes a lot of effort and time to form.

In addition, reinforcing materials such as reinforcing bars are often buried in covered concrete such as fireproof coatings, but in order to bury these reinforcing bars, it is necessary to assemble reinforcing materials such as reinforcing bars at the construction site. However, there is a problem in that this work requires a lot of effort and time.

Furthermore, since the covering concrete such as the above-mentioned fireproof coating is cast directly onto the outer circumferential portion of the steel pipe, it adheres to the steel pipe. Therefore, for example, if an axial force is applied to the concrete inside the steel pipe due to an earthquake, causing the steel pipe to displace horizontally, or if the steel pipe becomes strained in the direction in which its diameter expands, or if the steel pipe becomes distorted due to the heat of burning. In some cases, this displacement or strain is directly transmitted to the fireproof coating, and the fireproof coating absorbs this displacement or strain. This is not possible and breaks such as cracks or defects occur, which is unfavorable in terms of fire resistance and appearance, and also requires time and effort to repair.

The present invention has been made in view of the above circumstances, and allows for the construction of filled steel pipe concrete columns easily at the construction site, and furthermore, in the constructed filled steel pipe concrete columns, a certain degree of distortion in the steel pipes can be avoided in buildings. The object of the present invention is to provide a filled steel pipe concrete column that is free from the risk of cracking, destruction, or damage to the covered concrete, such as a fireproof coating, even if such occurrence occurs after the completion of the concrete column.

In the present invention, a covering concrete made of precast concrete is provided in advance around the outer periphery of the steel pipe via a buffer layer, and the inside of the steel pipe is filled using this steel pipe as a formwork. The above problem was solved by a filled steel pipe concrete column equipped with concrete 1.

[Operation] A steel pipe (hereinafter referred to as a PC steel pipe) is formed in advance in a factory or the like with a covering concrete made of the precast concrete described above (hereinafter referred to as a PC steel pipe), and after this is carried to the construction site, this PC steel pipe is used to By constructing filled steel pipe concrete columns, concrete coverings such as fireproof coatings can be installed.
There is no need to form 1. at the construction site, and therefore it is possible to easily construct a filled steel pipe concrete column with covered concrete. In addition, by forming the covering concrete at a predetermined distance from the outer circumferential surface of the steel pipe, it is possible to separate the steel pipe from the covering concrete such as the fireproof covering, and this allows horizontal displacement and distortion caused in the steel pipe to be removed from the fireproof covering. It is not transmitted to the covered concrete such as.

"Example" Hereinafter, an example of a filled steel pipe concrete column of the present invention will be described in detail with reference to FIGS. 1 to 3.

As shown in FIG.
It is composed of a C steel pipe 3 as a formwork and concrete 4 filled inside the formwork. ” On the bipedal base 2,
A fixing pile 5 for fixing the filled steel pipe concrete column to the slab 1 via the base 2 is removed, one end of which protrudes into the base 2, and the other end protrudes into the base 2. The end portion of the PC steel pipe 3 is deeply (buried) within the slab 1. Furthermore, reinforcing bars or the like may be provided in advance inside the PC steel pipe 3 to reinforce the concrete 4.

2. As shown in FIGS. 1 and 2, the PC steel pipe 3 consists of a steel pipe 6 and a covering concrete 7 formed with a predetermined gap from the outer peripheral surface of the steel pipe 6. A buffer layer 8 formed by filling the outer peripheral surface of the steel pipe 6 with foamed polyethylene is formed in the gap between the steel pipe 6 and the covering concrete 7.

The steel pipe 6 is cylindrical and has an unbonded layer coated with asphalt or the like on its inner peripheral surface. This unbonding treatment layer is provided to separate the steel pipe 6 and the concrete 4 when the concrete 4 is filled inside the steel pipe 6. A ring-shaped bottom portion 9 is formed to protrude outward from the outer periphery.The bottom portion 9 is fitted with a bipedal fixing stake 5, and a PC steel pipe 3 is inserted through the base 2. A fixing hole (not shown) for fixing to the slab 1 is formed.

The covering concrete 7 has a cylindrical shape with an inner diameter larger than the outer diameter of the steel pipe 6, and there are reinforcing bars IO inside.
is buried. In addition, as shown in FIGS. 1 to 3, at both ends of the covered concrete 7, there are formed holes for fastening the covered concrete side fixing fittings and the steel pipe side fixing fittings with bolts and nuts, which will be described later. A plurality of bolt fastening openings (hereinafter referred to as handball) I+, which are rectangular cutouts, are formed.

As the material of this covering concrete 7, ordinary concrete or lightweight concrete is used.

A buffer layer 8 (") is provided between the steel pipe 6 and the covering concrete 7, and as shown in FIG. This is due to the space formed by passing through the steel pipe 6, and is provided in order to absorb the horizontal displacement and strain generated in the steel pipe 6 and to prevent this strain from being transmitted to the covering concrete 7.

When filling the gap between the buffer layers 8 with a filler as a buffer material, the material is not limited to foamed polyethylene, but can be made of foamed plastics such as styrofoam or urethane foam, or soft plastics that occur in the steel pipe 6. Any material that has 4 f flexibility to absorb displacement and strain may be used. Further, the shape is not limited to a sheet-like shape, and may be filled with granular materials, or may be formed by injecting an uncured liquid into the gap between the steel pipe 6 and the covering concrete 7 and causing it to foam and harden.

As shown in FIGS. 1 and 3, the steel pipe 6 and the covering concrete 7 have a gap between the steel pipe 6 and the covering concrete 7,
That is, they are connected and fixed by a plurality of fixtures 12 formed near both ends of the buffer layer 8. These fixtures 12 are provided to fix the positional relationship between the steel pipe 6 and the covering concrete 7 when transporting the PC steel pipe 3 from the factory to the construction site.

The fixing devices 12 include a plurality of steel pipe-side fixing fittings 13 provided on the outer circumferential surface of the steel pipe 6, and a plurality of fixing fittings 13 disposed on the inner circumferential surface of the covered concrete 7 at positions corresponding to these steel pipe-side fixing fittings 13. Covered concrete side fixing fittings 14..., steel pipe side fixing fittings 13..., and fireproof concrete side fixing fittings 1
It consists of bolts and nuts 15 for fastening 4 and .

The steel pipe side fixing fitting 13 is a plate-shaped member that protrudes outward from the outer circumferential surface near both ends of the steel pipe 6, and has a long hole formed in the radial direction of the steel pipe near its tip. .

Further, the covering concrete side fixing fitting 14 is an L-shaped plate-shaped member housed in the hand hole 11 formed at both ends of the covering concrete 7, and one end thereof is connected to the opening of the hand hole 11. Covering concrete 7 from the opposite end
The other end, which is buried inside, extends from the hand hole 11 toward the buffer layer 8 side. The end of the covering concrete-side fixing fitting 14 on the buffer layer 8 side is arranged such that its surface faces the surface of the steel pipe-side fixing fitting 13 and the respective surfaces are in contact with each other. A hole is formed in the vicinity of the tip of the covered concrete side fixing metal fitting 14 at a position corresponding to approximately the center of the long hole of the steel pipe side fixing metal fitting.

A bolt is inserted into the elongated hole of the bipedal steel pipe side fixing fitting 13 and a hole of the covered concrete side fixing fitting 14 opposite to this steel pipe side fixing fitting 13. That is, the steel pipe side fixing fitting 13 and the covered concrete side fixing fitting 14 are connected by bolts and nuts 15.

The fastening strength between the steel pipe side fixing fitting I3 and the covered concrete side fixing fitting 14 using the bolt/nut 15 is as follows:
When the pipe is transported to a construction site etc., the steel pipe side fixing bracket 13
The bolts of the two-leg bolt/nut 15 are tightened to the extent that they do not shift in the elongated hole, and after construction is completed at the construction site as described later, axial force is applied to the concrete 1-4 inside. The bolts are fastened to such an extent that when the steel pipe 6 is strained in the direction in which its diameter expands, the bolt can be displaced within the elongated hole of the steel pipe side fixing fitting 13.

Further, the position of the hunt hole 11 on the bottom 9 side of the covered concrete 1 and 7 can be arranged so as to match the position of the fixing hole (not shown) formed in the bottom 9 of the double continuous steel pipe 6. preferable. This is because by arranging the hand hole 11 in this manner, the work of fastening the end of the fixing pile 5 protruding from the base 2 to this fixing hole can be performed within the hunt hole II.

Next, a method of constructing this PC steel pipe 3 will be explained.

First, a plurality of steel pipe side fixing fittings 13 are attached to the outer circumferential surface near both ends of the steel pipe 6 by welding or the like.

This attachment position is preferably between a fixing hole formed in the bottom 9 of the steel pipe 6 and the like.

Next, a sheet of foamed polyethylene is wound around the outer peripheral surface of the steel pipe 6 to form a buffer layer 8. After forming the buffer layer 8 in this manner, the reinforcing bars 10 are assembled around the buffer layer 8 by connecting linear vertical reinforcing bars extending in the axial direction of the steel pipe 6 and ring-shaped horizontal reinforcing bars extending in the circumferential direction by welding or the like. Here, a rectangular notch for the hunt pole 11 is formed in advance at both ends of the assembled cylindrical reinforcing bar lO, and one end of the covering concrete side fixing fitting 14 is further formed in this part. The parts are fixed to the corresponding reinforcing bars by welding, etc. The cutout for the hunt hole 11 is located at a position 1δ between the steel pipe fixing fittings 13, and furthermore, the cutout for the steel pipe fixing fittings 13...
4 are disposed at positions facing and abutting against the surface of the steel pipe side fixing fitting 13 described in 1.

Next, a formwork is constructed around this reinforcing bar IO, and a buffer layer 8 is
Covering concrete 7 is formed by pouring concrete between the mold and the mold.

At the same time, cover concrete 1/side fixing metal fittings 14
The end of the side fixed to the reinforcing bar IO is buried, and the covering concrete side fixing fitting 14 is fixed to the covering concrete 1-7.

1 After forming the covering concrete 7 in this way, the formwork is removed. Next, insert your hand through the hunt hole 11 and attach the steel pipe side fixing fitting 13 and the covered concrete side fixing fitting 1.
4 are fastened using a bolt nut 15 so that the fastening strength is as described above. Furthermore, covered concrete 7
By finishing the surface, the PC steel pipe 3 is formed.

Next, fill steel pipe concrete using this PC steel pipe 3)
The construction procedure for the pillars will be explained.

First, in a factory etc., a PC steel pipe 3 is
form. Next, after carrying this PC steel pipe 3 to a construction site, it is erected on the base 2 of the slab 1. When installing the PC upright on the base 2, place the PC so that one end of the fixing stake 5 protruding above the base 2 is inserted into the fixing hole in the bottom 9 of the steel pipe 6.
The steel pipes 3 are arranged and erected. Next, by bolting one end of the fixing pile 5 and the fixing hole in the hand hole 11, the PC steel pipe 3 is fixed to the slab l via the base 2.

After the PC steel pipe 3 is erected on the slab l, concrete 4 is cast and filled into the PCC steel pipe 3, and if necessary, mortar etc. is filled into the hand ball 11.
The construction of the filled steel pipe concrete columns will be completed.

In the filled steel pipe concrete column obtained in this way, the positional relationship between the steel pipe 6 and the covering concrete 7 is
- Since the I:IC steel pipe 3 is fixed by , the positional relationship between the covering concrete 7 and the steel pipe 6 does not shift when the IC steel pipe 3 is carried to the construction site. Therefore, a gap between the steel pipe 6 and the covering concrete 7 is ensured even when the pipe is transported to a construction site.

In addition, if an axial force is applied to the concrete 4 after the filled steel pipe concrete column is constructed, and distortion occurs in the direction in which the diameter of the steel pipe 6 expands, the bolt/nut 15 of the fixture 12 will fix the steel pipe side. Since the metal fitting 13 moves in a shifted manner within the elongated hole, the strain generated in the steel pipe 6 is not transmitted to the covering concrete 7. Therefore, even if the steel pipe 6 is distorted, the covering concrete 7 can be prevented from cracking or chipping.

Next, another embodiment of the filled steel pipe concrete column of the present invention will be described with reference to FIGS. 4 and 5.

This filled steel pipe concrete column differs from the above embodiments in three points: the shape of the fixture, the position of the handball 11 in the covering concrete 7, and the buffer layer 8.

In this embodiment, the fixture is as shown in FIG.
The bottom side fixture 24, most of which is housed in the hand hole 11 of the covered concrete 7, and the covered concrete 1
・A plurality of single-shaped spacers 25 attached to the inner circumferential surface of 7. Here, in this embodiment, the hand hole 11 is formed only at the end on the bottom 9 side of the covering concrete 7, unlike the above embodiment.

The two-legged bottom side fixture 24 includes a steel pipe side fixture 26 attached to the outer periphery of the steel pipe 6 near the end on the bottom 9 side, and a covered concrete side fixture 27 formed in the hand hole 11 of the covered concrete 7. , and bolts and nuts 15 for fastening these fixtures.

1. The steel pipe side fixture 26 is a rectangular plate attached to the outer circumferential surface of the steel pipe 6 so as to protrude outward, and is bent at a right angle at approximately the center and extends in the circumferential direction (hereinafter referred to as This circumferentially extending portion is referred to as a bent portion 28.) A hole for the port nut 15 is formed approximately at the center of the bent portion 28.

The covering concrete side fixture 27 has a rectangular plate shape, and one end is embedded and fixed in the fireproof covering from the end face opposite to the opening of the hand hole, and the other end is It is disposed so as to face and abut the bent portion 28 of the steel pipe side fixture 26. Furthermore, holes for fastening with bolts and nuts 15 are formed at positions corresponding to the holes of the bent portion 28 of the covered concrete side fixture 27.

The two-shaped spacer 25 has a rectangular planar shape and a substantially Z-shaped vertical cross section, and is a covered concrete side plate that is buried parallel to the axial direction in the covered concrete 7 and fixed. 29, and a connecting plate 30 that is bent at an obtuse angle from the covered concrete side plate 29 of 5 and extends from inside the covered concrete 7 into the buffer layer 8.
and a steel pipe side plate 31 which is formed by bending the connecting plate 30 at an obtuse angle so as to be substantially horizontal with the covered concrete side plate 29 and extending along the axial direction of the outer peripheral surface of the steel pipe 6. The steel pipe side plate 31 is pressed against the outer circumferential surface of the steel pipe 6 by the urging force of the connecting plate 30 and is in contact with the outer circumferential surface of the steel pipe 6.

The 1-shaped spacers 25 are arranged at approximately equal intervals in the circumferential direction and the axial direction on the inner circumferential surface of the covering concrete 7,
installed.

These double-shaped spacers 25 are provided in order for the steel pipe side plate 3 to urge the steel pipe 6 toward its center, thereby positioning the steel pipe and the covering concrete.

Further, the buffer layer 8 in this embodiment is different from the above embodiments in that it is not filled with foamed plastic or the like, and the buffer layer 8 has a space.

Next, a method for manufacturing the PC steel pipe 3 in this example will be explained.

First, cylindrical reinforcing bars 10 for reinforcing the covered concrete 1 and 7 are assembled. Next, the covered concrete side fixture 27 and the covered concrete side plate 29 of the single-shaped spacer 25 are fixed to predetermined positions of the reinforcing bars 7 by welding or the like. Next, a formwork is built around the reinforcing bars 10 and concrete is cast to fix the covering concrete side fixtures 27, and further to form a cylindrical covering concrete 7 with double-shaped spacers 25 fixed to the inner peripheral surface. do. At the same time, a hunt hole 11 is formed at the end of the bottom 9 of the covering concrete 7.

Next, the covering concrete 7 is lowered from the "1" end side of the steel pipe 6 which has been erected on the floor etc. in advance, so that the steel pipe 6 is inside the covering concrete 7, and the covering concrete 7 is lowered into the steel pipe. The outer periphery of 6 is surrounded by covering concrete 1-7.

At this time, the steel pipe side fixture 26 and the covered conocrete side fixture 27 are attached to the steel pipe 6 in advance on the bottom 9 side.
Finely adjust the position of the covering concrete 7 in the circumferential direction so that they are in opposing positions. Next, the PC steel pipe 3 is formed by fastening these ring-concrete-side fixtures 27 and steel pipe-side fixtures 26 in the hand hole II with a porto-nara I.15.

The I)C steel pipe 3 thus formed is constructed into a filled steel pipe concrete column in the same manner as in the first embodiment described above.

In this embodiment, since the Z-shaped spacer 25 is used to fix the positional relationship between the steel pipe 6 and the covering concrete 7, the action of the Z-shaped spacer 25 prevents the spacer from getting caught on the steel pipe 6. Smoothly.”
Two continuous PC steel pipes 3 can be constructed.

In addition, the filled steel pipe concrete column of this example is made of steel pipe 6
The positional relationship between the and covering concrete 7 is Z-shaped spacer 2
5 and the bottom side fixing part 24. Therefore, when manufacturing the PC steel pipe 3, after forming the covering concrete 7 in advance, this covering concrete 7 is attached to the steel pipe 6.
It can be covered around the area. Therefore, since only the covering concrete 7 can be manufactured separately in advance, it is preferable to manufacture it in a factory or the like.

Furthermore, in this embodiment, the axial positional relationship between the steel pipe 6 and the covering concrete 7 is determined by the bottom side fixing part 24.
and fix the radial position using the Z-shaped spacer 25.
Since the PC steel pipe 3 is fixed at the construction site, the positional relationship between the covering concrete 7 and the steel pipe 6 does not shift when the PC steel pipe 3 is delivered to the construction site. Therefore, even when the steel pipe is delivered to the construction site,
A gap 4 to the buffer layer 8 between the concrete and the covering concrete 7 is ensured.

Furthermore, even if an axial force is applied to the concrete 4 after the filled steel pipe concrete column is constructed, and distortion occurs in the direction in which the diameter of the steel pipe 6 expands, the Z-shaped spacer 25 will prevent the steel pipe 6 from moving in the radial direction. Since it is biased inward,
Can it easily absorb radial strain? Also, in the bottom side fixing part 24, the covering concrete side fixing tool 2
7 can absorb strain and radial strain. Further, when a horizontal displacement occurs due to an external force such as an earthquake, the displacement can be absorbed by the bottom fixing member 24. Therefore, the strain or displacement generated in the steel pipe 6 is not transmitted to the covering concrete 7, and the occurrence of cracks, chips, etc. in the covering concrete 7 can be prevented.

``Effects of the Invention'' - As explained above, the present invention provides a steel pipe (PC steel pipe) in which a covering concrete made of Bregeast concrete is preliminarily provided on the outer periphery of the steel pipe via a buffer layer, and a molded steel pipe for forming the steel pipe. Since it is a filled steel pipe concrete column, it is characterized by having concrete filled inside it, so a PC@tube is formed in advance in a factory etc., and after it is delivered to the construction site, the inside of the PC@tube is filled with concrete. By pouring concrete, filled steel pipe concrete can be easily constructed on site.

Therefore, the conventional work to form covered concrete, such as assembling formwork, pouring concrete, and removing formwork, or the work of assembling reinforcing bars to reinforce covered concrete, etc., can be significantly reduced. be able to.

Furthermore, in the filled steel pipe concrete column obtained by the present invention, a buffer layer is provided between the steel pipe and the covering concrete, so that the steel pipe and the covering concrete are separated. Therefore, it may be exposed to other external forces during an earthquake, or
C When an axial force is applied to the concrete inside the steel pipe, causing displacement in the horizontal direction or strain in the direction in which the diameter of the steel pipe expands, or due to a sudden change in room temperature such as during a fire, the steel pipe may be strained. Even if such displacement or strain occurs, the buffer layer absorbs this strain, so that the displacement or strain is not transmitted to the covering concrete. Therefore, cracks, chips, etc. do not occur in the covered concrete, the appearance of the filled steel pipe concrete column is not impaired, and there is no need for the cost and effort of repairs.

Furthermore, since the surface finishing of the fireproof coating can be done in a factory or the like, there is no need to finish the surface of the coated concrete 5 at the construction site. Furthermore, since surface finishing can be done in a factory or the like, the finished surface of the filled steel pipe concrete column is in good condition.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing a filled steel pipe concrete column of the present invention, Fig. 2 is a schematic perspective view showing a PC steel pipe used in the invention, and Fig. 3 is a schematic sectional view showing a fixture used for the PC steel pipe. , FIG. 4 is a schematic cross-sectional view showing another embodiment of the present invention, and FIG. 5 is a cross-sectional view thereof taken along the arrows. 3...PCj14 pipe, 4...Concrete, 6...Steel pipe, 7...Fireproof coating, buffer layer.

Claims (1)

[Claims] A filled steel pipe concrete column comprising a steel pipe in which a covering concrete made of precast concrete is preliminarily provided on the outer periphery of the steel pipe via a buffer layer, and concrete filled inside the steel pipe using the steel pipe as a formwork. .