JPH0448136B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a building structure constructed of columns and beams.

"Prior Art" The most common types of building structures are reinforced concrete structures (RC structures) and steel frame structures (S structures), but various other structures have also been proposed.

For example, a structure is known in which the outside of the column of a reinforced concrete structure is covered with a steel pipe, or in other words, the column is reinforced by forming a reinforced concrete column inside the steel pipe. According to this structure, the steel pipe exerts a so-called confining effect by tightening the internal concrete from the outside, so there is an advantage that the compressive strength of the concrete increases and the cross-sectional size of the column can be small. Furthermore, if steel pipes are used as formwork during concrete pouring, there is the advantage that on-site work becomes easier.

In addition, a filled steel pipe concrete structure is also known as a type of S construction. This involves using a steel pipe as the steel frame for the column, filling the inside of this steel pipe with concrete, and joining the beam steel frame to the steel pipe.

``Problems to be solved by the invention'' By the way, in the above-mentioned structure in which the columns are reinforced with steel pipes, the columns themselves inside the hard pipes are no different from conventional RC structures, and Since the steel pipes are not connected to each other, the columns inside the steel pipes bear not only compressive loads but also bending loads, which naturally requires column reinforcing bars (main bars and hoop bars). Therefore, in the above structure, although the dimensions of the columns can be made slightly smaller and the formwork construction can be omitted,
This advantage is offset by the cost of the steel pipe and the work to install the steel pipe, so it is not very effective in terms of construction cost and construction period.

Furthermore, although the above-mentioned filled steel pipe concrete structure does not require reinforcing steel work or formwork work, it is disadvantageous in terms of cost since the entire structure is basically S construction.

This invention was made in view of the above circumstances, and aims to provide a building structure that can reduce construction costs and shorten the construction period.

"Means for Solving Problems" This invention provides a building structure constructed of columns and beams, in which the beams are made of reinforced concrete, and the columns are placed under the beams on each floor. A steel pipe concrete structure is constructed in which steel pipes are vertically connected to each other by reinforcing bars via the beams and the insides of these steel pipes are filled with concrete, and furthermore, the plurality of reinforcing bars protruding from the upper ends of the steel pipes are connected upwardly. Accordingly, the steel pipe is inclined in a direction approaching the axis of the steel pipe, and a plurality of reinforcing bars are fixed to the lower inner surface of the steel pipe at predetermined intervals along the cross section of the steel pipe.

"Function" This invention is a structure in which the beams are made of reinforced concrete and the columns are made of steel pipe concrete. In addition to bearing the bending load, the concrete filled inside the steel pipe also bears the compressive load. Further, since the plurality of reinforcing bars protruding from the upper end of the steel pipe are each inclined in a direction approaching the axis of the steel pipe as they move upward, construction can be easily carried out by covering the steel pipe with another steel pipe to be connected to the steel pipe. Multiple reinforcing bars are fixed at predetermined intervals along the cross section of the steel pipes on the lower inner surface of the steel pipes to be connected, which increases the adhesion of the filled concrete and ensures a strong connection between the steel pipes. Become.

"Example" Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an elevational sectional view showing a part of the structure of this embodiment, and FIG. 2 is a perspective view showing a pillar structural member C used in constructing this structure.

In Figure 1, symbols A ₁ to _{A 3} are pillars on each floor,
B ₁ and B ₂ are beams. Beams B ₁ and B ₂ are similar to conventional reinforced concrete (RC) beams having main beam reinforcement and stirrups.

In addition, columns A ₁ to _{A 3} on each floor are equipped with unreinforced steel pipes 1 with a circular cross section placed under the beams (from the floor of that floor to the lower end of the beam on the upper floor). It is said to be constructed of steel pipe concrete filled with concrete 2. Pillars A ₁ to _{A 3} on each floor are:
The reinforcing bars 3... are connected to each other via beams _B1 or _B2 , forming columns that extend from the bottom floor to the top floor of this building as a whole. These pillars A ₁
The steel pipe 1 and the reinforcing bars 3 connecting them in ~ _A3 bear the bending load in place of the column reinforcing bars (column main bars and hoop bars) in conventional RC columns.

Next, the procedure for constructing this structure will be explained. Prior to that, the column structural member C that is effective when constructing this structure will be explained with reference to FIG. 2.

This pillar structural member (hereinafter simply referred to as a pillar member) C has the above-mentioned reinforcing bars 3 on top of the above-mentioned steel pipe 1.
... are welded and fixed in advance. In other words, this column member C has a length dimension equal to the beam bottom dimension of the floor of the building, and a diameter dimension equal to the column A ₁ ~
A plurality of reinforcing bars ₃ (eight in this example) are placed at equal intervals on the upper inner surface of the steel pipe 1 whose cross-sectional dimension is equal to A 3.
The lower part of ... is welded. These reinforcing bars 3...
... protrude from the upper end of the steel pipe 1 and extend upward, the middle portions of each are slightly bent so as to be slightly inclined inward, and their upper portions are arranged along the circumference. That is, the plurality of reinforcing bars 3 protruding from the upper end of the steel pipe 1 are each inclined in a direction closer to the axis of the steel pipe 1 as they move upward. Further, a plurality of reinforcing bars 4 (seven in this example) are fixed to the lower inner surface of the steel pipe 1 at predetermined intervals along the cross section of the steel pipe 1 by welding.

The first
To construct the structure shown in the figure, first erect column member C ₁ on the lowest floor of the building, and arrange beam reinforcing bars to intersect with the middle part of the reinforcing bars 3 of column member C ₁ . . Then, a beam formwork and a floor formwork (both not shown) are attached, and concrete 2 is poured inside these formworks and inside the steel pipe 1. As a result, the column A ₁ on the floor, the beam B ₁ on the floor above it, and the floor (not shown) are formed, and the upper portions of the reinforcing bars 3 of the column member C ₁ protrude onto the beam B ₁ .

Then, the reinforcing bar 3 protruding from the beam B ₁
Place the lower part of another column member C ₂ over it. At this time, since the upper portions of the reinforcing bars 3 are bent inward, the steel pipe 1 can be easily placed over them. Then, in the same way as above, construct beam reinforcing bars, beam formwork, and floor formwork on the top of the column member _C2 , pour concrete 2, and connect the column _A2 of this floor, the floor above it, and the beam _B2. and form the floor.

By doing this, the lower part of the steel pipe 1 of the column member C ₂ and the reinforcing bars 3 of the column member C ₁ on the lower floor are wrapped,
They are structurally connected together by the adhesive force of the concrete 2. Moreover, since the inner surface of the steel pipe 1 is made into a non-smooth surface by the reinforcing bars 4, the adhesion force is increased and the connection is sufficiently strong.

By repeating the above steps in sequence, the columns are extended to the upper floors, beams and floors are formed, and the entire structure is constructed.

As explained above, this structure consists of a steel pipe 1
and the reinforcing bars 3 that connect them...
Since it bears the bending load instead of the column reinforcing bars in RC columns, it is only necessary to fill the inside of the steel pipe 1 with unreinforced concrete, and the assembly of reinforcing bars (column main bars, hoop bars) in conventional RC columns is easy. No construction work is required. In addition, the columns A ₁ to _{A 3} on each floor can be extremely easily connected using lap joints by simply overlapping the reinforcing bars 3 and the lower part of the steel pipe 1, and there is no need for formwork for the columns. Compared to constructing conventional RC columns or columns reinforced with steel pipes,
Work on site is significantly reduced and construction period can be shortened.

Furthermore, this structure is advantageous in terms of construction cost when compared to conventional steel frame structures or filled steel pipe concrete structures because the beams B ₁ and B ₂ are made of RC structures.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, precast concrete beams may be used for beams B ₁ and B ₂ , and in this case, the construction period can be further shortened. Also, in the above column A ₁ ~
Although the cross-sectional shape of _A3 , that is, the cross-sectional shape of the steel pipe 1, is circular, it is not limited to circular and may be square.

Furthermore, in the column member C used above, the adhesion of the concrete 2 was increased by welding the reinforcing bars 4... to the inner surface of the lower part of the steel pipe 1, but instead of attaching the reinforcing bars 4..., for example, steel pipe 1
A ribbed steel pipe having ribs formed on the inner surface itself may be used. Note that the reinforcing bars 4...or ribs may be omitted if sufficient adhesion of the concrete 2 to the steel pipe 1 can be expected, but if this cannot be expected, then only the lower part of the steel pipe 1 should be omitted. Instead, it may be provided over the entire length.

"Effects of the Invention" As explained in detail above, in this invention, the beam is made of reinforced concrete and the column is made of steel pipe concrete, so the column can be constructed by simply filling the inside of the steel pipe with unreinforced concrete. This eliminates the need for assembling column reinforcing bars or column formwork when constructing conventional RC columns. Therefore, compared to constructing conventional RC columns or columns reinforced with steel pipes, on-site work is significantly reduced and the construction period can be shortened. It has the effect of being able to do it. Furthermore, since the beam is made of reinforced concrete, it is advantageous in terms of cost compared to the case where the entire structure is made of steel frame or filled steel pipe concrete.

Furthermore, since the plurality of reinforcing bars protruding from the upper end of the steel pipe are inclined in a direction that approaches the axis of the steel pipe as they move upward, it is possible to easily cover other steel pipes to be connected during construction. In addition to having the effect of further reducing the work burden, multiple reinforcing bars are fixed to the inner surface of the lower part of the steel pipe at predetermined intervals along the cross section of the steel pipe, increasing the adhesion of the filled concrete. This also has the effect of making the connection between the steel pipes connected together stronger.

[Brief explanation of drawings]

1 and 2 are diagrams showing an embodiment of the present invention, in which FIG. 1 is an elevational sectional view showing a part of the structure of this embodiment, and FIG. 2 is a diagram showing the construction of this structure. FIG. 2 is a perspective view (partially cut away) of a structural member for a column used for the construction. A ₁ , A ₂ , A ₃ ... Column, B ₁ , B ₂ ... Beam, C ... Structural member for column, 1 ... Steel pipe, 2 ... Concrete,
3...Reinforced steel.

Claims (1)

[Claims] 1. In a building structure constructed of columns and beams, the beams are made of reinforced concrete, and the columns are constructed by connecting steel pipes placed under the beams on each floor through the beams with a plurality of reinforcing bars. A steel pipe concrete structure is constructed in which the steel pipes are connected to each other in the vertical direction and filled with concrete, and each of the plurality of reinforcing bars protruding from the upper end of the steel pipe is inclined in a direction approaching the axis of the steel pipe as it goes upward. and a plurality of reinforcing bars are fixed to the lower inner surface of the steel pipe at predetermined intervals along the cross section of the steel pipe.