JP4603413B2 - Corrugated steel web girder manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a corrugated steel web girder using corrugated steel sheets for the web.

  Conventionally, as a method of joining corrugated steel plates to upper and lower floor slab concrete in corrugated steel web girders, flange plates are welded to the upper and lower ends of the corrugated steel plates, stud gibbles are welded to the flange plates, and stud gibels are implanted. A stud joining method is known in which corrugated steel plates and upper and lower floor slab concrete are joined via a flange plate.

However, since such a stud joining method is costly, it is excellent in workability and economy, and the corrugated steel sheet and the upper and lower floor slab concrete are joined by embedding the corrugated steel sheet in the upper and lower floor slab concrete. A buried bonding method has been developed and put into practical use. As the embedded joining method, for example, a plurality of holes are formed in the vicinity of the upper and lower end portions of the corrugated steel sheet, through-penetrating rebars are inserted into the holes, and constrained reinforcing bars are welded to the upper and lower end portions of the corrugated steel sheet. A method of joining by embedding in concrete is known (for example, see Non-Patent Document 1).
Kazuyuki Mizuguchi, 5 others, Design and construction of Motoya Bridge-Corrugated steel sheet web PC box girder bridge by overhang construction method, "Bridge and foundation", Construction books, Inc., September 1, 1998, Vol. 32, No. 9, p. 2-10

  By applying the embedded joining method as the joining method between the corrugated steel sheet and the upper and lower floor slab concrete in the corrugated steel web girder, as described above, it can be constructed at lower cost and more efficiently than when the stud joining method is applied. .

  In general, corrugated steel sheets are corrugated by bending with a press, but it is difficult to bend the steel sheets according to the designed dimensions, so the original size of the corrugated steel sheets produced is less than the designed dimensions. Errors may occur. Therefore, when manufacturing corrugated steel sheet web girders by embedding corrugated steel sheets in the upper and lower floor slab concrete by embedding and joining method, the corrugated plate of the concrete form for placing the upper and lower floor slab concrete is made into the corrugated shape of the corrugated steel sheet. In order to make it match, it is necessary to work the finely adjusted slat plate in accordance with the corrugated shape of the corrugated steel sheet on the basis of the original size of the corrugated steel sheet, resulting in poor productivity. In addition, there is a difficulty in processing the siding board in the field without a gap between the side surface of the corrugated steel sheet and the siding board. There is a risk of leakage from the gap.

  Moreover, in the corrugated steel web girder manufactured by applying the above-described embedding method, the side surface of the corrugated steel sheet embedded in the upper and lower floor slab concrete is in direct contact with the upper and lower floor slab concrete. In general, it is known that the adhesive force between a steel member and a concrete member is weak, and there is a possibility that adhesion failure may be caused at a joint portion between the side surface of the steel plate and the upper and lower floor slab concrete. Furthermore, there is a possibility that water such as water droplets or rain water adhering to the corrugated steel sheet due to condensation flows into the joining portion and penetrates.

  In view of the above circumstances, the present invention completely prevents the cast concrete from leaking between the side surface of the corrugated steel sheet and the slats, and processes the slats on the spot according to the corrugated shape of the corrugated steel sheets. An object of the present invention is to provide a method for manufacturing a corrugated steel web girder with improved productivity.

  The manufacturing method of the corrugated steel sheet web girder of the present invention that achieves the above object, in producing corrugated steel sheet web girders by embedding corrugated steel sheet webs in the upper and lower floor slab concrete by an embedded joining method, The concrete is placed by interposing a member that closes the gap between the concrete formwork and the siding plate.

  Here, the “member that closes the gap” in the present invention is provided with a mounting portion on the side of the gap plate, interposed between the mounting portion and the side surface of the corrugated steel plate, It is a long member that is crimped to eliminate gaps, and refers to, for example, an elastic material, rubber, plastics, or a cushioning material having elasticity.

  The method for manufacturing a corrugated steel web girder according to the present invention is for placing concrete through a member that closes the gap between the side surface of the corrugated steel sheet and the dam plate. Therefore, according to the method for manufacturing the corrugated steel web girder of the present invention, due to the above-described factors, an error occurs between the original dimension of the corrugated steel sheet and the designed dimension. Even if a gap is generated between the two, the above-mentioned member closes the gap, so that the concrete that has been placed is completely prevented from leaking, and the scallop is made into the corrugated shape of the corrugated steel sheet on site. This eliminates the need to work together and improves productivity. In addition, when an elastic material, rubber, or a member having elasticity is applied as the “member for closing the gap”, the corrugated steel sheet has shifted from the specified position, for example, when placing concrete. Even so, it is possible to avoid the occurrence of a gap due to the deformability of this member.

  Here, in the manufacturing method of the corrugated steel web girder according to the present invention, the concrete mold supports the reaction force on the left and right frames of the concrete mold and presses the side surfaces of the corrugated steel from both sides. It is preferable to provide a positioning member that fixes the relative position between the corrugated steel sheet and its concrete formwork.

  According to the manufacturing method of the corrugated steel web girder provided with such a positioning member, the corrugated steel plate is fixed at a predetermined related position. Further, when an elastic material, rubber, or a member having elasticity is applied as the “member for closing the gap”, for example, when placing concrete, the corrugated steel sheet is displaced from the specified relational position. Is prevented.

  In the method of manufacturing a corrugated steel web girder according to the present invention, it is further preferable that the positioning member has a position adjusting mechanism for adjusting a relative position between the corrugated steel plate and the frame of the concrete formwork.

  When the positioning member has such a position adjusting mechanism, the corrugated steel sheet can be positioned more accurately at a predetermined related position. As such a position adjusting mechanism, a wedge, a screw jack or the like may be used.

  Further, in the method for producing a corrugated steel sheet web girder according to the present invention, after applying an adhesive to the side of the steel sheet embedded in the upper and lower floor slab concrete of the corrugated steel sheet, and attaching powder particles to the adhesive It is also a preferred form to assemble concrete forms for upper and lower floor slabs.

  By attaching the granular material to the adhesive applied to the side surface of the steel plate, the surface area of the side surface of the steel plate is increased. Therefore, in the corrugated steel web girder manufactured by embedding the corrugated steel sheet with powder particles attached to the steel sheet side surface in the upper and lower floor slab concrete by the embedded joining method, the joint part between the steel sheet side surface and the upper and lower floor slab concrete As the adhesion surface area increases, the adhesion force due to the meshing between the granular material and the concrete increases, and an adhesion force equal to or greater than the tensile strength of the concrete is ensured at this joint. As a result, it is possible to prevent the adhesion between the side surface of the steel plate and the concrete from being cut off at the joined portion. Moreover, since the water shielding effect in a joining part is acquired by ensuring such adhesive force, it prevents that water permeate | transmits into the joining part by the factor mentioned above, and corrosion resistance improves.

  Furthermore, as the method for producing the corrugated steel web girder of the present invention, various types of adhesives can be used. In particular, epoxy resin adhesives are suitable, and the granular material has strength. It is more preferable to use silica sand or fine sand which is high and excellent in biting property.

  According to the method for manufacturing a corrugated steel web girder of the present invention, since the concrete is placed through a member that closes the gap between the side surface of the corrugated steel sheet and the siding plate, it is completely possible that the placed concrete leaks. In addition, it is unnecessary to perform the work of processing the weir plate in accordance with the corrugated shape of the corrugated steel sheet in the field, which improves productivity.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 3 is a cross-sectional view of a corrugated steel web girder manufactured by applying one embodiment of a method for producing a corrugated steel web girder according to the present invention, and FIG. 4 is a side view of the corrugated steel web girder shown in FIG. FIG. 5 is a perspective view of the corrugated steel sheet seen through from the upper floor slab concrete side of the corrugated steel web girder shown in FIG.

  Hereinafter, the process of manufacturing the corrugated steel web girder 1 using the corrugated steel 10 shown in FIGS. 3 to 5 for the web will be described. The corrugated steel web girder 1 of the present embodiment is formed by embedding the corrugated steel sheet 10 in the upper floor slab concrete 21 and the lower floor slab concrete 22 as a joining method of the corrugated steel sheet 10 and the upper and lower floor slab concrete 21 and 22. An embedded joining method for joining the corrugated steel sheet 10 and the upper and lower floor slab concrete 21 and 22 is applied.

  First, using a press machine (not shown), the corrugated steel sheet 10 is manufactured by bending the steel sheet according to the designed dimensions to perform corrugation.

  Next, for example, a hot dip galvanizing process is performed on the corrugated steel sheet 10 manufactured in the pressing process as necessary (steel sheet surface treatment process).

  Next, an epoxy resin adhesive 30 (see FIGS. 7 and 8) is applied to the side surfaces 11 and 12 (see FIG. 6) of the corrugated steel sheet 10 in the portions embedded in the upper and lower floor slab concrete 21 and 22. Then, silica sand 40 (see FIGS. 7 and 8) is attached to the epoxy resin adhesive (silica sand attaching step). The epoxy resin adhesive 30 is an example of the adhesive of the present invention, and the silica sand 40 is an example of the granular material of the present invention. In addition, the detailed description regarding this silica sand adhesion process is mentioned later.

  Next, the upper and lower floor slab concrete shown in FIGS. 3 and 4 is applied to the corrugated steel plate 10 in which the silica sand 40 (see FIGS. 7 and 8) is attached to the steel plate side surfaces 11 and 12 (see FIG. 6) in the silica sand attaching step. After assembling concrete molds for placing 21 and 22, placing reinforcing bars, PC steel, sheaths, etc. at predetermined positions, concrete is placed (concrete placing step).

  Here, with reference to FIG. 1, FIG. 2, the said concrete placement process is explained in full detail.

  FIG. 1 is a cross-sectional view showing a state in which concrete forms of upper and lower floor slabs are assembled with corrugated steel sheets, and upper and lower floor slab concretes are placed, and FIG. It is an enlarged view of the boundary part with the dam plate.

  FIG. 1 shows the upper and lower floors of a corrugated steel sheet 10 (see FIGS. 7 and 8) in which silica sand 40 (see FIGS. 7 and 8) is attached to the side surfaces 11 and 12 (see FIG. 6) of the steel sheet. The state where the concrete formwork 50 of the plate is assembled and the upper and lower floor slab concrete 21 and 22 is placed is shown. Further, FIG. 2 shows a boundary portion between the corrugated steel plate 10 shown in FIG. 1 and the slat plate 51 of the concrete mold 50.

  As shown in FIGS. 1 and 2, a mounting portion 511 is provided on the slat plate 51 of the concrete mold 50. As an example of a member that closes the gap, a cushioning material 60 having elasticity is attached to the attachment portion 511. The buffer material 60 is attached to the attachment portion 511 in a state where the upper and lower surfaces and one side surface are constrained and compressed.

  In the above-described pressing process in which corrugation is performed by bending with a press machine, it is difficult to bend the steel sheet according to the designed dimensions. Therefore, the original size of the corrugated steel sheet 10 manufactured in this pressing process is Errors may occur for the designed dimensions. However, when the concrete mold 50 to which the cushioning material 60 is attached is assembled in this way, the cushioning material 60 is crimped to the side surface of the corrugated steel sheet 10, so that a gap is generated between the side surface of the corrugated steel sheet 10 and the dam plate 51. Even so, the cushioning member 60 closes the gap. Therefore, it is possible to completely prevent the placed concrete from leaking, and it is not necessary to work the siding plate 51 in accordance with the corrugated shape of the corrugated steel plate 10 at the site, thereby improving productivity. Further, for example, even when the corrugated steel sheet 10 is displaced from a predetermined position when placing concrete, it is possible to avoid the occurrence of a gap due to the deformability of the cushioning material 60.

  As shown in FIGS. 1 and 2, the corrugated steel sheet 50 is formed by supporting the reaction force on the left and right frames 52 of the concrete mold 50 and pressing the side surfaces of the corrugated steel sheet 10 from both sides. A positioning member 70 is provided for fixing a relative position between the concrete mold 10 and the concrete mold 50. Here, after the corrugated steel sheet 10 is arranged at a predetermined position, the corrugated steel sheet 10 is fixed to the concrete formwork 50 with bolts 80 by fixing the positioning members 70 respectively pressing the side surfaces of the corrugated steel sheet 10 from both sides. Fixed in position. For this reason, the corrugated steel sheet 10 is prevented from being displaced from a predetermined relational position, for example, when placing concrete.

  In this embodiment, the example in which the relative position of the corrugated steel sheet 10 is fixed by fixing the positioning member 70 to the concrete mold 50 with the bolt 80 is shown. For example, the frame 50 may have a position adjusting mechanism such as a wedge or a screw jack that adjusts the position of the frame 50 relative to the frame 52. When the positioning member 70 has such a position adjusting mechanism, the corrugated steel sheet 10 can be positioned more accurately at a predetermined related position.

  Here, with reference to FIGS. 6-8, the said silica sand adhesion process is explained in full detail.

  FIG. 6 is a side view of a corrugated steel sheet showing a side surface of the steel plate of the portion embedded in the upper and lower floor slab concrete shown in FIGS. 3 and 4, and FIG. 7 is an epoxy resin system on the side surface of the steel sheet shown in FIG. FIG. 8 is a longitudinal sectional view of a corrugated steel sheet to which an adhesive is applied and silica sand is attached, and FIG. 8 is an enlarged view of the corrugated steel sheet side surface of the corrugated steel sheet shown in FIG.

  FIG. 6 shows a part of the corrugated steel sheet 10. 6 are embedded in the upper and lower floor slab concrete 21 and 22 of the corrugated steel web girder 1 shown in FIG. 3 and FIG. It is the steel plate side of the part to be done.

  As shown in FIGS. 7 and 8, an epoxy resin adhesive 30 is applied to the steel plate side surfaces 11 and 12 of the corrugated steel plate 10 shown in FIG. In addition, the application amount and application method of the epoxy resin adhesive 30 depend on the regulations of the epoxy resin adhesive to be used. In the present embodiment, “Alpron D-12” (trade name) (Nippon Resin Co., Ltd .: Adhesive for raising concrete and mortar joints) is used as the epoxy resin adhesive 30, and this adhesive is 0.3 It is applied with a coating thickness of about 2.0 mm.

  Further, as shown in FIGS. 7 and 8, the particle diameter of about 0.2 mm to 5.0 mm from above the applied epoxy resin adhesive 30 within the effective bonding time of the epoxy resin adhesive 30. Sprinkle silica sand 40 having As the epoxy resin adhesive 30 is cured, the dispersed silica sand 40 is attached to the epoxy resin adhesive. If the particle size is less than 0.2 mm, the effect of meshing with concrete is small, and if it exceeds 5.0 mm, the balance between the size and the adhesive force is not appropriate.

  By attaching the silica sand 40 to the epoxy resin adhesive 30 applied to the steel plate side surfaces 11 and 12 of the corrugated steel plate 10 in the silica sand attaching step described above, the surface areas of the steel plate side surfaces 11 and 12 are increased. Silica sand is preferable because it has high strength and a constant particle size, and is excellent in biting and reproducibility into concrete to be placed.

  The corrugated steel web girder 1 (see FIGS. 3 to 5) of the present embodiment is manufactured by applying the embedded joining method as described above, and the corrugated steel plate 10 has upper and lower floor slab concrete 21 and 22. The buried steel plate side surfaces 11 and 12 and the upper and lower floor slab concrete 21 and 22 are in direct contact with each other.

  In general, it is known that the adhesion between a steel member and a concrete member is weak. Since the silica sand 40 is attached to the steel plate side surfaces 11 and 12 of the corrugated steel plate 10 of the present embodiment in the silica sand attaching step, the corrugated steel plate 10 with the silica sand 40 attached to the steel plate side surfaces 11 and 12 is embedded by a bonding method. Adhesive surface area at the joint between the steel plate side surfaces 11 and 12 and the upper and lower floor slab concrete 21 and 22 in the corrugated steel web girder 1 embedded in the upper and lower floor slab concrete 21 and 22 (see FIGS. 3 to 5). Will increase. Furthermore, the adhesion force due to the meshing between the silica sand 40 and the concrete is increased, and an adhesion force equal to or higher than the tensile strength of the concrete is ensured at the joint portion.

  As a result, the adhesion between the steel plate side surfaces 11 and 12 and the upper and lower floor slab concrete 21 and 22 is prevented at this joint portion. Further, since such an adhesion force is ensured, a water shielding effect at the joint portion is obtained, so that water such as water droplets and rainwater adhering to the corrugated steel plate due to condensation may flow into the joint portion and penetrate. It is blocked and the corrosion resistance is improved.

  Finally, the concrete cast in the concrete placing process is cured and the concrete formwork 50 is removed to produce the corrugated steel web girder 1 shown in FIGS.

  In the above-described embodiment, the example in which the member that closes the gap is an elastic cushioning material has been described. However, the member that closes the gap is not limited to this, and for example, an elastic material or rubber As long as it is interposed between the attachment portion and the side surface of the corrugated steel plate, such as plastics, it can be crimped to the side surface of the corrugated steel plate to eliminate the gap.

  Moreover, although the adhesive agent of this invention demonstrated the example which is an epoxy resin adhesive in embodiment mentioned above, the adhesive agent of this invention is not restricted to this, It is with respect to both a steel plate and concrete. And any adhesive having strong adhesiveness.

  In the above-described embodiment, the example in which the granular material of the present invention is silica sand has been described. However, the granular material of the present invention is not limited to this, and for example, has high strength and biting property. Fine sand or the like may be used as long as it has a particle size that maximizes the adhesion surface area between the cast concrete and the powder. In addition, since there exists a possibility that it may fall at the time of construction when using a very large granular material, what has a particle size of 5 mm or less is preferable.

  Further, in the above-described embodiment, in order to secure the adhesion between the corrugated steel plate and the upper and lower floor slab concrete, the silica sand deposition process is introduced. The present invention can be applied to various uses that require adhesion between the members. Specific examples of applications to which this technique can be applied include the joining of corrugated steel sheets of the corrugated steel web girder described above and concrete, for example, joining of steel pipes and concrete of steel-concrete composite truss bridges, steel The part where the strut is embedded in concrete, the joint part in the steel-concrete composite structure, the joint part between the steel pipe and concrete of the steel pipe arch bridge, the joint part between steel and concrete in the main tower where the steel shell cell is embedded And a part where a steel pipe column is embedded in concrete.

It is sectional drawing which shows the state by which the concrete form of the upper and lower floor slab was assembled with the corrugated steel plate, and the upper and lower floor slab concrete was laid. It is an enlarged view of the boundary part of the corrugated steel plate shown in FIG. It is sectional drawing of the corrugated steel web girder manufactured by applying one Embodiment of the manufacturing method of the corrugated steel web girder of this invention. FIG. 4 is a side view of the corrugated steel web girder shown in FIG. 3. FIG. 5 is a perspective view of the corrugated steel sheet seen from the upper floor slab concrete side of the corrugated steel sheet web girder shown in FIG. 4. It is a side view of the corrugated steel sheet in which the steel plate side surface of the portion embedded in the upper and lower floor slab concrete shown in FIGS. 3 and 4 is shown. It is a longitudinal cross-sectional view of the corrugated steel sheet in which an epoxy resin adhesive is applied to the side surface of the steel sheet shown in FIG. It is an enlarged view of the steel plate side surface of the corrugated steel plate shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Corrugated steel web girder 10 Corrugated steel plate 11,12 Steel plate side surface 21 Upper floor slab concrete 22 Lower floor slab concrete 30 Epoxy resin adhesive 40 Silica sand 50 Concrete formwork 51 Slat board 511 Mounting part 52 Frame 60 Buffering material 70 Positioning member 80 Bolt

Claims (6)

When manufacturing corrugated steel web girder by embedding corrugated steel web in upper and lower floor slab concrete by embedding and joining method, elastic material, rubber, plastics are placed in the gap between the side of corrugated steel and the crest of concrete formwork. And a member that closes the gap while absorbing an error that occurs between the original size of the corrugated steel sheet and the design dimension of the corrugated steel sheet, consisting of any of cushioning materials having elasticity , A positioning member is attached to the concrete mold to support the reaction force on the left and right frames of the concrete mold and to press the side surfaces of the corrugated steel from both sides to fix the relative position of the corrugated steel and the concrete mold. A method of manufacturing a corrugated steel web girder characterized by casting concrete.   2. The corrugated steel sheet web according to claim 1, wherein a member for closing the gap is interposed in a gap between a side surface of the corrugated steel sheet and a slat of the concrete formwork in a state where the member is compressed. Girder manufacturing method. The method for manufacturing a corrugated steel web girder according to claim 1 or 2 , wherein the positioning member has a position adjusting mechanism for adjusting a relative position between the corrugated steel plate and the frame of the concrete formwork . The adhesive is applied to the side of the steel plate in the portion of the corrugated steel sheet embedded in the upper and lower floor slab concrete, and after the powder is attached to the adhesive, the concrete form of the upper and lower floor slab is assembled. Item 4. A method for producing a corrugated steel web girder according to any one of Items 1 to 3. 5. The method for producing a corrugated steel web girder according to claim 4 , wherein the adhesive is an epoxy resin adhesive, and the granular material is silica sand or fine sand . 6. The method for producing a corrugated steel web girder according to claim 4 , wherein the granular material has a particle size of 0.2 mm to 5.0 mm .

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