JP4954925B2 - Concrete filled steel segment - Google Patents

Description

  The present invention relates to a concrete-filled steel segment in which concrete is packed inside a steel shell, and particularly suitable for filling in a sewer, a rainwater main line, a road tunnel, etc. in which secondary lining is omitted. Regarding the steel segment.

  As a kind of segment constituting a cylindrical structure such as a shield tunnel, a concrete-filled steel segment in which concrete is packed inside a steel shell having a main girder, a skin plate, and a joint plate is known. Such a concrete-filled steel segment can obtain high rigidity when the concrete resists a compressive load and the steel shell resists a tensile load.

  FIG. 8 shows a configuration example of the concrete-filled steel segment 7. The steel segment 7 is connected with a plurality of vertical ribs 72 arranged between the main girders 71 at predetermined intervals, and the end portions of the main girders 71 are joined with a joint plate 73. A steel shell 70 is formed by connecting a skin plate 74 to the outside of the plate 73. Inside the steel shell 70 is filled concrete 75.

  In particular, when the segment 7 is manufactured, since the concrete 75 is cast after the steel shell 70 is manufactured, the filled concrete 75 contracts with time, and the steel shell 70 and the concrete 75 A gap is formed between the two, and the gap increases with time. Further, when handling after the segment is produced, the concrete 75 is wrinkled or peeled off, and a gap is formed between the steel shell 70 and the concrete 75.

  Such a concrete filling segment 7 is connected in the circumferential direction to form a segment ring, and further, this segment ring is connected in the axial direction to construct a tunnel. At this time, after actually constructing the tunnel, a so-called secondary lining, in which concrete is further cast on the inner surface, may be omitted. That is, when this secondary lining is omitted, on the inner surface side of the tunnel, the inner surface side end portion of the steel shell 70 composed of the above-mentioned filling concrete 75, the main girder 71 and the joint plate 73 is exposed. It will be.

  When a tunnel in which such secondary lining is omitted is applied to a tunnel in a corrosive environment such as a sewer, a rainwater main line, a road tunnel, etc., the steel shell 70 exposed on the inner surface side and There is a high possibility of moisture entering the gap with the concrete 75. Actually, since the steel material constituting the steel shell 70 forms a passive film with respect to the alkaline concrete 75, corrosion due to the steel material coming into contact with the concrete 75 does not occur. However, if a component that neutralizes alkali is mixed in the moisture that permeates into the gap, the above-described passive film is eroded and eventually the steel shell 70 is corroded.

  For this reason, the anticorrosion method as shown, for example in patent document 1 is proposed conventionally. In the technique disclosed in Patent Document 1, as shown in FIG. 9, a corrosion-resistant anticorrosive metal foil 83 is attached to the main girder 81 and the inner end surface 81a of the joint plate (not shown) with an adhesive. At this time, the anticorrosive metal foil 83 is produced in a groove shape, and when it is actually fitted to the inner air surface side end surface 81a, it is stuck with an electrically insulating adhesive.

  However, since the main girder 81 is curved in an arc shape, the anticorrosion metal foil 83 itself needs to be curved in an arc shape in order to fit the anticorrosion metal foil 83 therein. However, in order to make the anticorrosive metal foil 83 configured in the groove shape into a curved state, it is forced to perform difficult processing, which is expensive in manufacturing. In the disclosed technique of Patent Document 1, the anticorrosion metal foil requires special processing at the welded portion of the main girder 81, a joint plate (not shown) and the main girder, which increases the burden of labor and increases the production cost. However, there was a problem that it was impossible to escape.

  Further, in the disclosed technique of Patent Document 2, as shown in FIG. 10, the polymer cement layer 103 is provided on the surface of the steel materials 106 and 111 in contact with the concrete 112, and the concrete 112 is provided outside the polymer cement layer 103. However, the disclosed technique of Patent Document 2 has a problem that since the application area of the polymer cement layer 103 is wide, the manufacturing process is prolonged and the manufacturing cost is remarkably increased. .

  In addition, as a conventional method for preventing corrosion of a segment, a method of coating the entire inner surface of the steel shell or the vicinity of the inner surface of the segment has also been proposed, but since the coating area is wide, the manufacturing process is There was a problem that the manufacturing cost increased dramatically as the length increased.

  In addition, in any of the above methods, it is not possible to follow the gap formed at the boundary between the steel plate and the concrete such as main girders, vertical ribs, and joint plates, which can be generated during concrete shrinkage and handling, and water and ions enter the gap, resulting in a result. As a result, there is a problem that the corrosion resistance of steel plates such as main girders, vertical ribs, and joint plates in a range where metal foil or coating is not applied cannot be secured.

Furthermore, since the steel plate and the concrete such as the main girder and joint plate are in surface contact with each other, the gap generated at the boundary surface between the steel plate and the concrete such as the main girder and joint plate reaches the skin plate of the steel shell. In many cases, the surface of the steel plate not subjected to corrosion protection on the skin plate side may be corroded only by preventing corrosion only in the area close to the inner surface of the segment.
JP 7-82992 A JP-A-2005-232815

  Accordingly, the present invention has been devised in view of the above-described problems, and is a concrete filling that can realize corrosion prevention of a steel segment in which a concrete is filled in a steel shell at a lower cost and more effectively. The aim is to provide a steel segment.

  In order to solve the above-mentioned problems, the present inventor, after earnest research, in the concrete-filled steel segment, the corrosion of the steel shell is mainly caused by the neutralization of alkali. It was found that the corrosion of the steel shell can be prevented only by preventing the components that neutralize the alkali from being mixed into the gaps formed between the steel shells. In addition, this knowledge has provided the elastic body that covers the main girder and the interface between the joint plate and the concrete from the surface, thereby preventing the corrosion of the steel segment in which the concrete is packed inside the steel shell at a lower cost and It was found that it can be effectively realized.

That is, the concrete-filled steel segment according to claim 1 connects between a main girder that forms both side surfaces, a skin plate that covers at least an outer peripheral surface side between the main girder, and an end of the main girder. In a concrete-filled steel segment in which concrete is packed inside a steel shell having a joint plate, the boundary surface between the main girder and / or the joint plate and the concrete and the inner surface of the tunnel Characterized in that the elastic body covers the main girder and / or the joint plate even when the gap between the main girder and the joint plate and the concrete is increased. To do.

  Further, the concrete-filled steel segment according to claim 2 is the invention according to claim 1, wherein the elastic body is a resin or polymer cement having a zero-span elongation at break elongation of 0.5 mm or more. It is characterized by.

  Further, the concrete-filled steel segment according to claim 3 is the invention according to claim 1, wherein the elastic body is an epoxy resin, a tar epoxy resin, a vinyl ester resin, a silicon resin, a polyurethane resin, a fluororesin, an acrylic resin. A resin comprising any one of a rubber resin, a polybutadiene rubber-based resin, a chloroprene rubber-based resin and a polyester resin or a combination of two or more of them, or a polymer mainly composed of at least one of the above resins and cement. It is made of cement.

  The concrete-filled steel segment according to claim 4 is the invention according to any one of claims 1 to 3, wherein the elastic body has a film thickness of at least 50 μm or more.

  The concrete-filled steel segment according to claim 5 is the invention according to any one of claims 1 to 4, wherein the main girder and / or the joint plate is a web and at least an inner surface of the web. The elastic body covers a boundary surface between the flange formed on the inner surface and the concrete filled from the surface.

  In the present invention having the above-described configuration, the main girder and the interface between the joint plate and the concrete are covered with an elastic body from the surface. The gap increases due to the shrinkage and handling of the concrete, but the elastic body elastically deforms following the increase in the gap, so the gap is always shielded from the outside or from the outside (the inside of the tunnel). It becomes possible to suppress entry of corrosion factors such as moisture and various ions.

  In the present invention that can effectively prevent moisture and various ions from entering the gap, it is possible to prevent moisture and various ions from adhering to the main girder and joint plate exposed in the gap. As a result, it is possible to prevent or suppress corrosion of the steel plates constituting the main beam and the joint plate.

  Hereinafter, as a best mode for carrying out the present invention, a concrete filled steel segment in which concrete is packed inside a steel shell will be described in detail with reference to the drawings.

  The concrete-filled steel segment that is the subject of the present invention is a steel segment in which steel-filled concrete is filled in a steel shell produced by assembling or casting a steel plate, and concrete is filled in the steel shell. It is a synthetic segment.

  Hereinafter, as a best mode for carrying out the present invention, a segment connecting structure for connecting a plurality of segments in a staggered manner will be described in detail with reference to the drawings.

  FIG. 1 shows an example of a shield tunnel 3 to which a concrete-filled steel segment according to the present invention is applied. As shown in FIG. 1, the shield tunnel 3 is constructed by assembling a lining body in which a plurality of arc-shaped segments 4 are connected in a ring shape at a segment joint portion 65 on the inner surface of the tunnel. In this shield tunnel, in order to improve the structural yield strength and rigidity of the shield tunnel 3 as a whole, the segments 4 are connected in a staggered manner between the adjacent segment rings, and the segment rings are connected in the axial direction E. , Making this connection more robust. In order to actually form the shield tunnel 3, concrete may be cast at the bottom to form a flat floor f.

  As shown in FIG. 2, the segment 4 connects the two main girders 11 that form both side surfaces, the skin plate 12 that covers at least the outer peripheral surface side between the main girders 11, and the ends of the main girders 11. A steel shell 10 having a joint plate 13 and having vertical ribs 14 provided between the main girders 11 is provided. The steel shell 10 is filled with concrete as will be described later.

  The main girder 11 is formed in a shape divided in the circumferential direction of the segment ring, and has a shape curved with a predetermined curvature. This main girder 11 is obtained by processing a steel plate. The main girder 11 may be formed with joints, bolt insertion holes 22 and the like (not shown) for connecting with other segments 4 adjacent in the axial direction at a predetermined pitch.

  The joint plate 13 is extended in a substantially vertical direction with respect to the two main girders 11, is processed in advance to a length that allows connection between the ends of the main girders 11, and is fixed by welding. The joint plate 13 is provided with a bolt insertion hole 21 for constituting a segment ring by connecting with another segment 4 adjacent in the circumferential direction.

  The skin plate 12 is fixed to the main girder 11, the vertical rib 14 and the joint plate 13 by welding. This skin plate 12 forms the outer peripheral side steel plate of the segment ring, and is configured in a shape curved into a cylindrical peripheral surface shape.

  The vertical ribs 14 are arranged with a predetermined interval between the main beams 11. The vertical ribs 14 are arranged in a direction substantially parallel to the joint plate 13. The vertical ribs 14 are fixed to the main beam 11 and the skin plate 12 by welding. In the example shown in FIG. 2, the height of the vertical ribs 14 is set so as to be lower than the main beam 11 and the joint plate 13, but is not limited thereto, and is substantially the same height. You may make it comprise so that it may become.

  FIG. 3 shows a state in which concrete 23 is packed in the steel shell 10 having the above-described configuration. FIG. 4A shows the FF ′ cross section in FIG.

  The concrete 23 is poured from the inner surface of the steel shell 10 and is solidified to be filled in the steel shell 10. At this time, as shown in FIG. 4, the concrete 23 to be filled is inclined upward inward from the contact position with the inner peripheral surface side end surface 11a of the main girder 11 and forms a horizontal plane therefrom. However, the present invention is not limited to this. It may be filled so that the inner peripheral surface side end surface 11a of the main girder 11 and the inner surface of the concrete 23 have the same height.

  Moreover, in this invention, as shown to Fig.4 (a), the elastic body 18 which coat | covers the clearance gap 19 produced in the boundary surface of the main girder 11 and the concrete 23 or the boundary surface from the surface is further provided. That is, the elastic body 18 is attached so as to straddle between the inner peripheral surface side end surface 11 a of the main girder 11 of the steel shell 10 and the inner surface of the concrete 23.

  Further, as shown in FIG. 4B, the elastic body 18 may cover the boundary surface between the joint plate 13 and the concrete or the gap 19 generated on the boundary surface from the surface.

  Further, as shown in FIG. 4C, the elastic body 18 may cover the boundary surface between the longitudinal ribs 14 and the concrete 23 or the gap 19 generated on the boundary surface from the surface.

  This elastic body 18 is made of a material having a high ductility and a relatively low elastic modulus, and is made of a water-stopping material capable of preventing or suppressing permeation of water and various ions. As the required ductility, it is sufficient that a value of about 0.5 mm is obtained with zero span elongation, and preferably 1 mm or more is more sufficient. This ductility index is determined by the Japan Highway Public Research Institute's “Quality Standards Test for Concrete Coating Materials”. Two plates are placed next to each other without any gaps, and a material is applied or pasted onto these plates. And then pulling after curing. When this index satisfies 0.5 mm or more, even if the gap between the inner surface of the main girder and the joint plate and the inner empty surface of the above-filled concrete is expanded due to the contraction of the concrete or the handling of the segment, The coating can always block the boundary surface between the main girder and the joint plate and the concrete or the gap formed on the boundary surface from the ingress of moisture and various ions.

  As an example of the elastic body 18, a resin or polymer cement having zero span elongation of 0.5 mm or more may be applied.

  Examples of the elastic body 18 include any one of an epoxy resin, a tar epoxy resin, a vinyl ester resin, a silicon resin, a polyurethane resin, a fluororesin, an acrylic rubber resin, a polybutadiene rubber resin, a chloroprene rubber resin, and a polyester resin. Or a mixed resin obtained by combining two or more of these resins, or a polymer cement containing as a main component at least one of the above resins and a cement.

  The elastic body 18 may be made of a resin-based paint. That is, by mixing a resin, it is expected that the ductility is enhanced and the elastic modulus is kept low. Before applying these paints, it is desirable that the zinc rich primer is previously deposited in the application region of the main beam 11.

  Also, as an alternative to applying such resin paint, selected from the group consisting of polyurethane adhesives, natural rubber adhesives, synthetic rubber adhesives, silicone adhesives, acrylic adhesives, and polymer cements thereof The elastic body 18 may be configured by at least one kind.

  These materials are generally suitable for use as the elastic body 18 of the present invention because they are excellent in stretch performance as well as water stopping performance.

  FIG. 5 shows an example in which caulking materials 31 and 32 are applied as another example of the elastic body 18. In FIG. 5 (a), a relatively thin caulking material 31 is straddled from the inner peripheral side end surface 11a of the main girder (outer main girder) 11 to the inner surface of the concrete 23, and the caulking material 31 is This is coated by injecting into the gap 19. FIG. 5B shows an example in which a relatively thick caulking material 32 is straddled from the inner peripheral side end face 11 a of the main girder (outer main girder) 11 to the inner empty surface of the concrete 23. In this way, the surface of the caulking material 32 may be configured to cover the same height as the flat surface 23a of the concrete 23 to form the same flat surface.

  The caulking materials 31 and 32 are made of synthetic rubber, silicon rubber, or the like, both of which are made of an elastic material that has a low elastic coefficient, is rich in ductility, and exhibits water-stopping properties.

  When the segment 4 having the above-described configuration is actually manufactured, the concrete 23 is placed after the steel shell 10 is manufactured. At this time, a gap 19 is generated between the steel shell 10 and the concrete 23 due to shrinkage with time of the filled concrete 23 or impact during handling. 4 and 5, the gap 19 between the inner peripheral surface side end face 11b of the main girder (outer main girder) 11 and the concrete 23 is not present when the concrete 23 is placed. However, the concrete 23 gradually contracts with the passage of time, and the gap 19 increases with time. Further, when the segment is handled after the concrete is hardened, a gap 19 may be generated between the main beam 11 and the concrete 23 due to, for example, an impact. As a result, a gap 19 of about 0.1 to 0.3 mm may be finally formed.

  When covering with the elastic body 18 and the caulking materials 31 and 32 is performed after the gap 19 is formed, the gap 19 is straddled and attached as in the above-described example. As a result, the gap 19 is covered with the elastic body 18 and the caulking materials 31 and 32, and water and various ions can be prevented from entering the gap 19.

  Further, when the covering with the elastic body 18 and the caulking materials 31 and 32 is performed before the gap is increased, it is actually adhered to the boundary surface between the concrete 23 and the main girder 11 that are not separated from each other. Thereafter, even when the gap 19 between the concrete 23 and the main beam 11 suddenly occurs due to shrinkage of concrete or due to impact or the like, the elastic body 18 elastically deforms following the increase in the gap, so the gap 19 Can always be shielded from the outside, and the water-stopping property can be maintained.

  In general, when a component that neutralizes alkali is mixed in the adhering water, the passive film on the surface of the main girder 11 formed between the alkaline concrete 23 is eroded, and thus the main girder 11 is constituted. The steel plate to be corroded will be corroded. In particular, when the replacement of water and various ions is fast, the corrosion rate becomes large. However, in the present invention that can effectively prevent moisture and various ions from entering the gap 19, it is possible to prevent and suppress moisture and various ions from adhering to the main beam 11 exposed in the gap 19. . As a result, it is possible to prevent and suppress the corrosion of the steel plates constituting the main beam 11.

  In the present invention, not all the gaps 19 need to be filled. It is sufficient that the gap 19 can be always shielded from the ingress of moisture and various ions from the outside. Since it is not completely filled, the present invention can prevent the corrosion of the segment at low cost.

  In particular, when the segment 4 to which the present invention is applied is a tunnel that omits so-called secondary lining and is applied to a tunnel in a corrosive environment such as a sewer, a rainwater main line, a road tunnel, etc., the humidity However, in the present invention, the gap 19 can be completely shielded by the covering of the elastic body 18, so that the gap 19 can be completely shielded. In the case where the main girder 11, the joint plate 13, and the vertical ribs 14 are exposed on the inner surface of the tunnel, the vertical ribs 14 can be more effectively prevented from corrosion by the same means. It becomes possible. That is, the present invention has a particularly remarkable effect when applied to a tunnel that omits secondary lining and is in a corrosive environment such as a sewer.

  In the present invention, it is not necessary to fill all the gaps 19, and it is sufficient that the gaps 19 can be always shielded from the ingress of moisture and various ions from the outside. When it is not necessary to fill all the gaps 19, it is possible to perform the corrosion prevention of the segments at a lower cost.

  In particular, in the present invention, since the elastic body 18 has only to be attached or applied along the boundary surface between the main girder 11, the joint plate 13 and the longitudinal rib 14 and the concrete 23, the elastic body 18 is attached. The contact area and the application area can be minimized, the manufacturing process can be shortened, the burden of labor can be reduced, and the manufacturing cost can be reduced. Moreover, since the application area of the elastic body 18 can be reduced, it leads also to reduction of material cost.

  In the present invention, it is desirable that the elastic body 18 has a film thickness of at least 50 μm. The reason for this is that even when the gap 19 is finally increased to about 0.1 to 0.3 mm, the elastic body 18 is formed with a film thickness of 50 μm or more so that the film follows the increase in the gap 19. This is because elastic deformation can be performed while reducing the thickness, and the gap 19 can be prevented from being exposed to the surface of the segment 4. However, it is preferably 100 μm or more in order to suppress variations in construction. The maximum film thickness of the elastic body 18 is preferably 2 to 3 mm or less in the case shown in FIG. 5A from the viewpoint of ensuring the manufacturing cost and the inner surface smoothness, as shown in FIG. In the case shown, it is preferable to set the thickness below the concrete surface.

  Incidentally, in addition to the case where the main girder 11 is the outer main girder as described above, in the case where a middle main girder (not shown) extended in the circumferential direction at the center of the steel shell 10 is provided, in other words, the main girder 11 In the case of forming the middle main girder as well, similarly, by covering the gap (boundary surface) with the concrete 23 with the elastic body 18, the middle main girder (not shown) can be protected at a lower cost. .

  In the above-described example, the case where the main girder 11 is covered with the elastic body 18 from the inner peripheral surface side end surface 11a to the inner surface of the concrete 23 has been described as an example. However, the present invention is not limited to this case. For example, as shown in FIGS. 6A and 6B, the elastic body 18 may be covered from the surface with respect to the boundary surface between the joint plate 13 and the concrete 23 or the gap 29 generated on the boundary surface. . The gap 29 generated at the time of contraction and handling after placing the concrete 23 can be sealed by the elastic body 18, and the anticorrosion of the joint plate 13 by improving the water-stopping property can be realized.

  In addition, the present invention has an advantage in that moisture and various ions can be shielded by coating with an extremely simple work process such as applying or sticking the elastic body 18.

  The present invention can also be applied to the case where the main girder 40 includes the web 41, the inner air surface side flange 42a, and the outer peripheral surface side flange 42b as shown in FIG. Between the main girders 40, a skin plate 12 covering the outer peripheral surface side is laid and filled with concrete 23 inside.

  Here, the elastic body 18 covers from the surface a boundary surface between the flange 42a formed on the inner air surface side and the concrete 23 or a gap generated on the boundary surface. 7A illustrates the case where the elastic body 18 is covered over the entire surface of the flange 42a (the inner peripheral surface side end surface 51). However, the elastic body 18 is not limited to this case. Any coating area may be used as long as it covers at least the boundary surface between the flange 42a (inner peripheral surface side end surface 51) and the concrete 23 or a gap formed on the boundary surface.

  FIG. 7B shows an example in which a taper 52 is formed on the concrete 23 so that the side surface 53 of the end surface 51 on the inner peripheral surface side of the flange 42a is exposed on the surface. In such a case as well, the elastic body 18 is similarly covered from the surface of the boundary surface between the flange 42a and the concrete 23 (taper 52) or the gap formed on the boundary surface.

  In this example, the main girder has an H cross-sectional shape, but the flange on the outer peripheral surface side is not a necessary condition. Further, the cross-sectional shape of the main girder may be L-shaped or U-shaped. The above example is an example of the outer main girder, but the same configuration can be applied to the middle main girder.

  In such a segment having the main girder 40, even if a gap is generated between the inner peripheral surface side end face 52 of the flange 42a and the concrete 23 due to shrinkage of the cast concrete 23 or an impact during handling. Since the elastic body 18 is covered, the elastic body 18 can be elastically deformed following this, and as a result, the water-stopping property can be maintained, and the corrosion resistance of the steel material can be improved at a low cost.

  In addition, the elastic body 18 has any of epoxy resin, tar epoxy resin, vinyl ester resin, silicon resin, polyurethane resin, fluororesin, acrylic rubber resin, polybutadiene rubber resin, chloroprene rubber resin, and polyester resin. Metal foil, especially high corrosion-resistant metal on the polymer cement (the inner surface of the tunnel) that contains at least one of the above resins or a mixed resin that is a combination of two or more of the above resins and cement. It is also possible to affix a metal foil consisting of the following: In this case, it is more effective to prevent the penetration of water and various ions from the inner surface of the tunnel into the boundary surface between the steel shell and the concrete or the gap generated at the boundary surface. Needless to say.

It is a figure which shows the example of the shield tunnel to which the segment made from the concrete filling steel which concerns on this invention is applied. It is a figure for demonstrating the structure of the segment to which this invention is applied. It is a figure which shows the state which filled the concrete with respect to the steel shell. It is FF 'sectional drawing in FIG. It is a figure which shows the example which applied the caulking material as a substitute of an elastic body. It is a figure which shows the example which coat | covered the elastic body from the surface with respect to the interface (gap) of a joint board and concrete. It is a figure which shows the example which applied this invention with respect to NM segment. It is a figure which shows the structural example of the segment made from a concrete filling steel in the past. It is a figure for demonstrating a prior art. It is a figure for demonstrating another prior art.

Explanation of symbols

3 Shield tunnel 4 Segment 7 Concrete filled steel segment 10 Steel shell 11 Main girder
11a Inner peripheral surface side end surface 11b Inner side surface 12 Skin plate 13 Joint plate 14 Vertical rib 18 Elastic body 19 Gap 21 Segment joint bolt insertion hole 22 Ring joint bolt insertion hole 23 Concrete 29 Gap 31, 32 Caulking material 40 Main girder 41 Web 42 42a 42b Flange 51 Inner peripheral side end surface 52 of main girder flange Side surface 53 of inner peripheral surface side end surface of main girder flange Taper 65 Segment joint part 71 Main girder 72 Vertical rib 73 Joint plate 74 Skin plate 70 Steel shell 75 Filling Concrete 81 Main girder 83 Anticorrosive metal foil 103 Polymer cement layer 106, 111 Steel 112 Concrete

Claims (5)

Concrete is packed inside a steel shell having a main girder that forms both side surfaces, a skin plate that covers at least the outer peripheral surface between the main girder, and a joint plate that connects between the ends of the main girder. In the concrete filled steel segment,
An elastic body that covers a boundary surface between the main girder and the joint plate or the concrete and the concrete from the inner surface of the tunnel;
A concrete-filled steel segment characterized in that the elastic body follows and covers even when the gap between one or both of the main beam and the joint plate and the concrete is increased . The concrete-filled steel segment according to claim 1, wherein the elastic body is a resin or polymer cement having a zero-span elongation at break elongation of 0.5 mm or more. The elastic body is an epoxy resin, tar epoxy resin, vinyl ester resin, silicon resin, polyurethane resin, fluorine resin, acrylic rubber resin, polybutadiene rubber resin, chloroprene rubber resin, or polyester resin, or 2 3. The concrete-filled steel segment according to claim 1, comprising a mixed resin in which two or more kinds are combined, or a polymer cement mainly composed of at least one of the above resins and cement. The concrete-filled steel segment according to any one of claims 1 to 3, wherein the elastic body has a thickness of at least 50 µm or more. The main girder and / or joint plate has a web and a flange formed on at least the inner surface of the web,
The concrete according to any one of claims 1 to 4, wherein the elastic body covers a boundary surface between the flange formed on the inner surface side and the concrete packed in the middle from the surface. Filled steel segment.

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