JP4418330B2 - Bonding structure between concrete and steel - Google Patents

Description

  The present invention relates to a joint structure between a concrete material and a steel frame material. More specifically, the present invention relates to a joint structure between a concrete material and a steel frame material that facilitates the reuse of the steel frame material.

  Conventionally, in order to improve the proof stress and rigidity of a steel frame structure, the steel frame material is tightly coupled with a concrete material such as an RC slab (reinforced reinforced concrete plate) and reinforced. In this case, the concrete material is generally joined to the steel frame by a stud bolt attached to the steel frame.

  FIG. 4 shows an example of such a connection structure between a concrete material and a steel frame material (see Patent Document 1). In this coupling structure 100, as shown in FIG. 4, the male screw 101a provided at the tip of the stud bolt 101 is screwed into the female screw hole 102a provided in the upper flange of the steel frame (steel beam) 102. Thus, the stat bolt 101 is attached to the steel frame material 102. Then, the concrete material 103 is adhered to the stat bolt 101, and the concrete material 103 and the steel frame material 102 are coupled.

  As described above, conventionally, the steel structure is reinforced by firmly bonding the steel material 102 using the concrete material 103 and the stud bolt 101. Therefore, during disassembly, for example, while cutting and destroying the steel material 102 There is a problem that it is necessary to separate the concrete material 103 from the steel frame material 102, and it is difficult to reuse the steel material material 102 as it is for another building.

In order to avoid this, for example, a method of separating the steel material 102 and the concrete material 103 while holding the concrete material 103 at the joint portion may be considered. However, such work generates a large amount of noise and requires a lot of labor, and thus there are cases where construction is difficult in a residential area or the like and costs increase.
JP 2003-56127 A

  The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a joint structure of a concrete material and a steel material that can facilitate the reuse of the steel material.

The joint structure of the concrete material and the steel frame according to the present invention is characterized in that the steel frame and the concrete material are joined by a concrete fixing member fixed by brazing .

  In the combined structure of the concrete material and the steel frame of the present invention, it is preferable that a hole for fitting the concrete fixing member is provided on the surface of the steel frame.

Further, in the combined structure of the concrete material and the steel frame of the present invention, the steel frame is used as a column, the concrete material is a root-wrapped concrete, and a plurality of cavity generating members made of brazing metal in the root-wrap concrete, A predetermined arrangement with respect to the pillars, for example, may be embedded in parallel with the axial direction of the pillars.

  Furthermore, in the joint structure of the concrete material and the steel frame according to the present invention, the cavity generating member may have a predetermined shape, for example, a rod-shaped member, and the rod-shaped member may be embedded diagonally.

  According to the present invention, the concrete fixing member such as a stud bolt for binding the concrete material and the steel frame material is fixed by the low melting point metal. Therefore, at the time of dismantling, the metal is heated and melted to disassemble the concrete material and the steel frame. An excellent effect that the material can be easily separated is obtained.

  Hereinafter, although the present invention is explained based on an embodiment, referring to an accompanying drawing, the present invention is not limited only to this embodiment.

Embodiment 1
In FIG. 1, the joint structure of the concrete material and steel frame which concern on Embodiment 1 of this invention is shown.

  As shown in FIG. 1, the joint structure K includes a concrete material 2 and a steel frame so that a concrete material 2 made of RC slab is supported by a steel frame material (steel beam) 1 made of, for example, an H-shaped steel to form a floor 10. A coupling structure for coupling the material 1 is used. Here, a stud bolt (concrete fixing member) 3 is attached to the steel frame material 1, and the stud bolt 3 attached to the steel frame material 1 is embedded in the concrete material 2, and the steel frame material 1 and the concrete material 2. And are combined.

  In the coupling structure K of the embodiment, as shown in FIG. 2, the tip portion 3b of the shaft portion 3a of the stud bolt 3 is fitted into a hole 1a formed in the upper surface of the upper flange of the steel frame 1, A low melting point metal (hereinafter referred to as a weld metal) 4 is welded to the periphery, whereby the stud bolt 3 is attached to the steel frame 1. That is, the stud bolt 3 is brazed to the steel frame 1 by the weld metal 4. Here, for the weld metal 4, for example, zinc (melting point: 419 degrees Celsius) or tin (melting point: 232 degrees Celsius) is used.

  Further, in the joint structure K, at the time of disassembly, the weld metal 4 is heated and melted, and the brazed stud bolt 3 is removed from the steel frame 1. For this reason, the concrete material 2 and the steel frame material 1 can be easily separated without carrying out the work of suspending the concrete at the connecting portion or destroying the steel frame material 1. Therefore, the steel frame 1 can be reused as it is.

  Here, as a heating method for melting the weld metal 4, for example, heat generated by energization (joule heat) is used. That is, a predetermined voltage (relatively low voltage) is applied to the weld metal 4 so as to pass a large current so as to be 419 degrees Celsius or more for zinc and 232 degrees Celsius or more for tin.

  Alternatively, the weld metal 4 may be melted by so-called high frequency induction heating. The high-frequency induction heating is a method in which a coil to which a high-frequency alternating current is applied is brought close to a metal, and an eddy current is generated on the surface of the metal, thereby heating the metal.

  Alternatively, the weld metal 4 may be heated and melted with a gas burner.

  As described above, according to the coupling structure K of the first embodiment, the stud bolt 3 is attached to the steel frame 1 using the welding metal 4 having a low melting point, and the concrete material 2 and the steel frame 1 are coupled by the stud bolt 3. Is done. For this reason, at the time of dismantling, the concrete material 2 and the steel frame material 1 can be easily separated simply by heating and melting the weld metal 4.

  Therefore, the steel frame material 1 can be separated from the concrete material 2 without damage, and the steel frame material 1 can be reused as it is, for example, as a beam of another building.

  Moreover, since it is not necessary to hang concrete during demolition, it is possible to reduce noise and pollution of the demolition work.

  Further, since the stud bolt 3 is fitted into the hole 1a on the upper surface of the steel frame 1, it can receive a force acting in a direction parallel to the joint surface between the steel frame 1 and the concrete material 2 due to the engagement relationship. Therefore, as long as it is applied to a structure in which a force (particularly, a pulling force) in a direction perpendicular to the joint surface does not act, a problem of strength does not occur.

  The weld metal 4 is not limited to zinc or tin, but may be various low melting point metals (for example, solder). In addition, tin has a lower melting point than zinc. Therefore, it is more advantageous to use tin for disassembly. However, since the unit price of tin is 7 to 8 times that of zinc, zinc is the most suitable for practical use. It can be said that.

Embodiment 2
FIG. 3 shows a second embodiment of the present invention. The coupling structure K1 of the second embodiment is obtained by modifying the first embodiment, and is applied when reinforcing the column base portion of the steel pipe column 1A. Is done.

  That is, as shown in FIG. 3, the coupling structure K1 is applied when the concrete material 2A for root winding is coupled to the column base of the steel pipe column 1A as the steel frame material. Here, in the joint structure K1, a metal wire (cavity generating member) 14 made of a required number of low melting point metals (for example, zinc and tin) is provided inside the concrete material 2A in order to facilitate destruction during dismantling. It is assumed that it is embedded in a predetermined manner. For example, the metal wires 14 are embedded at a predetermined interval so as to be parallel to the axial direction along diagonal lines L1 and L2 of the cross section of the concrete material 2A. The metal wires 14 are not limited to the above, and can be appropriately arranged.

  With this configuration, at the time of dismantling, the metal wire 14 is heated and melted, so that “su” can be artificially generated inside the concrete material 2A. For this reason, the concrete material 2A can be destroyed with only a slight impact. Therefore, it can be easily separated from the concrete material 2A without damaging the steel pipe column 1A.

  Note that the steel pipe column 1A and the concrete material 2A are joined by a stud bolt 3A attached to the outer peripheral surface of the steel pipe column 1A, and a hole (not shown) in which the shaft tip of the stud bolt 3A is provided on the outer peripheral surface of the steel pipe column. It is the same as in the first embodiment in that the metal 4A having a low melting point is welded around the hole and the stud bolt 3A is brazed to the steel pipe column 1A.

  As described above, according to the second embodiment, the stud bolt 3A used for joining the steel pipe column 1A and the concrete material 2A is brazed by the weld metal 4A made of a low melting point metal and attached to the steel pipe column 1. In addition, since the metal wire 14 made of the same low melting point metal is embedded in the concrete material 2A in a predetermined manner, the welded metal 4A and the metal wire 14 can be easily melted from the steel pipe column 1A by heating and melting. 2A can be removed. Thereby, it becomes easy to reuse the steel pipe column 1A as the steel frame as it is.

  The present invention can be applied to various buildings having a joint structure of a concrete material and a steel frame material.

It is sectional drawing which shows typically the joint structure of the concrete material and steel frame which concern on Embodiment 1 of this invention. It is an enlarged view of the principal part of the joint structure. It is sectional drawing which shows typically the joint structure of the concrete material of Embodiment 2 of this invention, and a steel frame material. It is sectional drawing which shows typically the connection structure of the conventional concrete material and steel frame material.

Explanation of symbols

K, K1 Bonding structure 1, 1A Steel frame 2, 2A Concrete 3, 3, A Stud bolt (concrete fixing member)
4, 4A Weld metal (low melting point metal)
14 Cavity generating member

Claims (4)

A combined structure of a concrete material and a steel frame, characterized in that the steel frame and the concrete material are combined by a concrete fixing member fixed by brazing . The joint structure of a concrete material and a steel frame according to claim 1, wherein a hole for fitting a concrete fixing member is provided on the surface of the steel frame. Steel frames are used as pillars, concrete materials are used as root winding concrete,
3. The joint structure of concrete material and steel structure according to claim 1, wherein a plurality of cavity generating members made of brazing metal are embedded in the necklace concrete in a predetermined arrangement with respect to the columns. . The joint structure of a concrete material and a steel frame according to claim 3, wherein the cavity generating member has a predetermined shape.

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