JP2006265960A - Construction method of steel concrete composite structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method of a steel undeformable concrete composite structure due to welding heat in a butting part of steel materials. <P>SOLUTION: This method constructs the steel concrete composite structure for forming welding beads 31, 32 and 33 of a plurality of layers along the butt adjacent steel plates 1 and 1, by sticking a plurality of mutually joined steel plates 1, 1, etc. to a surface of concrete 2; and comprises a first welding process of blocking up clearance of the butt part while joining the adjacent steel plates 1 and 1 by forming the welding bead 31 of at least one layer along the butt part of the adjacent steel plates 1 and 1, a concrete placing process of placing the concrete 2 on the inner surface 1a side of the steel plates 1, and a second welding process of forming the residual welding beads 32 and 33 from the outside surface 1b side of the steel plates 1 after hardening the concrete 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for constructing a steel-concrete composite structure used for, for example, walls, floors, roofs (ceilings), columns, beams and the like.

  Conventionally, a steel-concrete composite structure in which concrete is placed between steel plates arranged to face each other is known (see, for example, Patent Document 1).

  In such a steel-concrete composite structure, a steel shell unit formed by facing a pair of steel plates is manufactured in a factory or the like, and a plurality of steel shell units are connected on site, and then the concrete is placed between the pair of steel plates. It is constructed by the procedure of placing. Adjacent steel shell units are joined by abutting the steel plates together and then performing welding without a break along the abutted portion. It is necessary to perform welding. That is, a plurality of layers of weld beads are formed in the thickness direction at the butt portion between the steel plates.

JP 5-44283 A (all pages)

  However, if the welding of the butt portion between the steel plates is completed before the concrete is placed (before hardening), there is a problem that the butt portion of the steel plate is deformed by the welding heat.

  Such a problem is also a problem that applies in common even when the steel shell unit is not used (that is, when a plurality of steel plates are built on site), and further, the steel plates are arranged only on one side of the concrete. This is also a problem that applies to the construction of a so-called open sandwich type steel-concrete composite structure.

  From such a viewpoint, an object of the present invention is to provide a method for constructing a steel concrete composite structure in which deformation due to welding heat hardly occurs in a butt portion of steel materials.

  The present invention constructs a steel-concrete composite structure in which concrete is cast on one surface side of a plurality of steel materials joined together and has a plurality of layers of weld beads along the abutting portion between the adjacent steel materials. A first welding step in which at least one weld bead is formed along a butt portion between adjacent steel materials, and the gap between the butt portions is closed while joining the adjacent steel materials; and the steel material A concrete placing process for placing concrete on one surface side of the steel sheet, and a second welding process for forming a remaining weld bead from the other surface side of the steel material after the concrete is hardened. .

  The present invention is characterized in that several layers of a plurality of layers of weld beads formed along butted portions between adjacent steel materials are formed before placing concrete and the rest are formed after hardening of the concrete. is there. When the concrete is hardened and united with the steel material, the steel material is restrained by the hardened concrete. Therefore, even if there is heat input due to welding in the second welding process, the steel material is hardly deformed. That is, according to the present invention, it is possible to construct a steel-concrete composite structure with less strain than in the case of a conventional method for constructing a steel-concrete composite structure in which welding of a butt portion is completed without being restricted by concrete. As a result, it is possible to realize a smooth surface that can be applied to paint finishing or the like.

  The steel-concrete composite structure according to the present invention is used only when a planar structure such as a wall or floor is constructed by abutting a plurality of plate-shaped steel materials (steel plates) in the width direction or the vertical (height) direction. It can also be applied to constructing a rod-like structure such as a column or a beam by butting a plurality of plate-shaped steel materials (steel plates) so as to form a predetermined angle (for example, 90 degrees), Further, the present invention can also be applied to a case where a plurality of tubular steel materials (steel pipes) are continuously arranged in contact with each other in the longitudinal direction and concrete is placed inside the steel pipe to construct a pile or a column.

  Moreover, the concrete may include not only coarse aggregates but also coarse aggregates (mortar). Moreover, you may embed a reinforcing bar etc. in concrete.

  When a steel concrete structure is constructed according to the procedure of the present invention, it is possible to obtain a steel concrete composite structure in which the deformation due to welding heat is small at the butt portion of the steel material.

  Hereinafter, the best mode for carrying out a steel-concrete composite structure (hereinafter simply referred to as “composite structure”) according to the present invention will be described in detail with reference to the accompanying drawings. In the following, the case where the composite structure is applied to a “wall” is illustrated, but in addition to the frame of a building structure such as a floor, roof (ceiling), pillar, beam, etc., a road floor slab, a bridge pier, and a buried tunnel Needless to say, the present invention can be applied to a structure of a civil engineering structure such as a body or a segment of a shield tunnel.

  As shown in FIG. 1A, the composite structure according to the present embodiment has a plurality of plate-shaped steel materials (hereinafter referred to as “steel plates”) 1, 1,. 1), and a plurality of layers (in this embodiment, three layers) along the abutting portion between the adjacent steel plates 1 and 1, as shown in FIG. 1 (b). It has weld beads 31, 32, 33.

  The composite structure according to this embodiment is a so-called full sandwich type composite structure in which the steel plates 1 are attached to both surfaces of the concrete 2.

  The steel plate 1 is made of a plate material mainly composed of iron or a plate material made of an aluminum alloy, and a plurality of shear connectors 11, 11,... Are fixed to the inner surface 1a (the surface attached to the concrete 2). The shear connector 11 is made of a steel headed stud having a head formed at one end of a shaft portion, and is fixed to the inner surface 1a of the steel plate 1 by stud welding or the like. The shape of the fore edge (groove) of the steel plate 1 is not particularly limited. For example, the shape when it is abutted against the edge of another steel plate 1 is an I shape, a V shape, a U shape, or the like. It can shape | mold so that it may become.

  Concrete 2 is mainly composed of cement, aggregate (fine aggregate, coarse aggregate) and water, but admixtures such as blast furnace slag, fly ash, steel fiber, water reducing agent, fluidizing agent, etc. It goes without saying that these admixtures may be kneaded. The concrete 2 may be a mortar that does not contain coarse aggregate.

  The weld beads 31, 32, 33 are stacked in the thickness direction of the steel plate 1. Of the three layers of weld beads 31, 32, 33, the weld bead 31 formed on the inner surface 1 a side of the steel plate 1 (attachment surface side with the concrete 2) is formed before placing the concrete 2. The remaining weld beads 32 and 33 formed on the weld bead 31 are formed after the concrete 2 is placed.

  Next, a method for constructing a synthetic structure will be described in detail. In addition, in this embodiment, as shown in FIG. 2, the case where the steel shell unit U formed by facing a pair of steel plates 1 and 1 is manufactured in a factory etc. is illustrated. .. Are fixed to the steel plate 1.

<Building process>
First, a plurality of steel shell units U, U,... Are connected at the site, and the steel plates 1, 1 that are adjacent to each other in the width direction or height (longitudinal) direction are abutted.

<First welding process>
Next, as shown in FIG. 3 (a), a weld bead 31 (see FIG. 3 (b)), which is the first layer, is formed along the abutting portion of the adjacent steel plates 1 and 1, and the adjacent steel plates are formed. The gap between the butted portions is closed while joining 1 and 1. More specifically, as shown in FIG. 3 (b), the backing material 12 is applied from the one surface side (the inner surface 1a side) to the abutting portion of the steel plates 1 and 1, and then the other surface side of the steel plate 1. Welding is performed from the (outer surface 1b side) so as to have a thickness of about one third of the thickness of the steel plate 1 to form a weld bead 31.

<Concrete placing process>
Subsequently, as shown in FIG. 4, concrete 2 is placed on the inner surface 1 a side of the steel plate 1. In this embodiment, fresh concrete 2 is placed between a pair of opposing steel plates 1 and 1 to make the space between the steel plates 1 and 1 dense.

<Second welding process>
Then, as shown in FIG. 5A, after the concrete 2 is hardened, the remaining weld beads 32 and 33 are formed from the outer surface 1 b side of the steel plate 1. More specifically, as shown in FIG. 5B, the outer surface of the first weld bead 31 has a thickness of about one third of the thickness of the steel plate 1 at the butt portion of the steel plates 1 and 1. The second-layer weld bead 32 is formed by welding from the outer surface 1b side of the steel plate 1, and the outer surface of the second-layer weld bead 32 has a thickness of about one third of the plate thickness of the steel plate 1. Thus, welding is performed from the outer surface 1b side of the steel plate 1 to form a third-layer weld bead 33.

  As described above, several layers (in this embodiment, one layer) of the multiple layers of weld beads 31, 32, 33 formed along the abutting portions of the adjacent steel plates 1, 1 are placed in concrete. When the former is formed and the rest is formed after the concrete 2 is hardened, a composite structure with less strain is constructed than in the conventional method of constructing a steel-concrete composite structure in which the welding of the butt portion is completed without any constraint by the concrete. As a result, it is possible to realize a smooth surface that can be applied to finish painting. That is, when the concrete 2 is hardened and integrated with the steel plate 1, the steel plate 1 is restrained by the hardened concrete 2, so even if there is heat input due to welding in the second welding process, the steel plate 1 is hardly deformed. .

  In the present embodiment, the three layers of weld beads 31, 32, 33 are formed at the abutting portions of the steel plates 1, 1. However, the present invention is not limited to this, and although not shown, the two layers of weld beads are omitted. Or four or more weld beads may be formed.

  In the present embodiment, one layer of weld beads 31 is formed before the concrete 2 is placed, and the remaining two layers of weld beads 32 and 33 are formed after the concrete 2 is hardened. However, the present invention is not limited to this. Alternatively, two layers of weld beads 31 and 32 may be formed before the concrete 2 is placed, and the remaining one layer of weld beads 33 may be formed after the concrete 2 is cured. In addition, although illustration is abbreviate | omitted, when forming four or more layers of weld beads, if at least one layer of weld beads is formed before the concrete 2 is placed, and the remaining weld beads are formed after the concrete 2 is cured. Good. The number of layers of weld beads to be formed before placing the concrete 2 may be determined in consideration of the plate thickness of the steel plate 1 and the magnitude of the side pressure of the concrete 2.

  In this embodiment, a full sandwich type composite structure in which a plurality of steel plates 1, 1,... Are connected to both sides of the concrete 2 is illustrated, but the present invention is not limited to this. Although omitted, the above-described construction method can also be applied when constructing an open sandwich type composite structure in which a plurality of steel plates are connected to only one side of the concrete 2.

(A) is sectional drawing of the steel concrete composite structure which concerns on embodiment of this invention, (b) is an enlarged view of the butt | matching part of steel plates. It is a perspective view for demonstrating the construction method of the steel concrete composite structure which concerns on embodiment of this invention. (A) is a perspective view for demonstrating a 1st welding process, (b) is sectional drawing similarly. It is a perspective view for demonstrating a concrete placement process. (A) is a perspective view for demonstrating a 2nd welding process, (b) is sectional drawing similarly.

Explanation of symbols

1 Steel plate 2 Concrete 31, 32, 33 Weld bead

Claims (1)

A method of constructing a steel-concrete composite structure in which concrete is cast on one side of a plurality of steel materials joined to each other and having a plurality of layers of weld beads along the abutting portion between the adjacent steel materials. ,
A first welding step of forming at least one weld bead along the abutting portion between adjacent steel materials, and closing the gap between the abutting portions while joining the adjacent steel materials;
A concrete placing step of placing concrete on one side of the steel material;
And a second welding step of forming a remaining weld bead from the other surface side of the steel material after the concrete is hardened.

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