JP2015200097A - Steel plate for concrete mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the strength of a building frame by controlling the spreading of steel plates due to lateral pressure generated during concrete casting and improving the adhesive strength of concrete on the steel plates.SOLUTION: A permanent column mold 1A is constructed using a plurality of column steel plate units 10 made by assembling a plurality of column steel plates 11 and covering the outer surface with a fiber sheet F, and a column 1 is erected by casting concrete C in the column mold 1A. Vertical ribs 8 and horizontal ribs 9 that have first protrusions 81,91 and second protrusions 91,92 are formed along the edge of the column steel plate 11, and a reinforcing bar is fixed as a reinforcement on an inner surface 13 of a main plate 12.

Description

  The present invention relates to a steel sheet for concrete formwork that is suitable for use mainly in building a frame of a concrete structure such as a building.

  For buildings such as columns and beams in buildings made of reinforced concrete or steel frames and reinforced concrete, formwork according to the outer shape of the building is constructed with concrete plywood at the site, and reinforcing bars and steel frames are installed inside the formwork as necessary. From this state, a construction method is known in which concrete is placed inside the formwork and the concrete plywood of the formwork is removed after curing the concrete (Patent Document 1).

  However, with this conventional method, it is necessary to remove the formwork, which is troublesome in terms of construction and increases the construction cost. Also, concrete plywood is usually lauan wood, which is used to cut and use raw wood. Has environmental problems. Therefore, a method has been considered in which a plurality of steel plates are used as a mold, and after the concrete is cast, the steel plates are left as permanent molds without being removed. When the steel plate is used as a concrete formwork in this way, the above-mentioned problems that have occurred in the case of concrete plywood are cleared, and there is an advantage that the steel plate becomes a part of the strength member and leads to an improvement in the strength of the frame.

JP 2011-094476 A

  However, when concrete is placed inside a formwork constructed using steel plates, the concrete pressure acts as a side pressure that pushes from the inside to the outside and works to spread the steel plates outwards, and the steel plates deform outwards. The problem of blistering is likely to occur. Moreover, since the adhesive force of the concrete with respect to the inner surface of a steel plate is low, there exists a possibility that concrete may peel from a steel plate, and there existed a surface which obstruct | occluded the strength improvement of the housing by a steel plate.

  The present invention has been made in view of the above circumstances, and the main technical problem thereof is that the spread of the steel sheet due to the lateral pressure generated at the time of placing the concrete is suppressed, and the adhesion strength of the concrete to the steel sheet is improved and both of them are improved. An object of the present invention is to provide a steel plate for concrete formwork in which the strength of the frame is improved by promoting the integration.

  A concrete formwork steel sheet according to claim 1 of the present invention is a steel sheet used as a permanent formwork for concrete in building or reinforcing a concrete frame, and projects from the inner surface to which the concrete contacts. A reinforcing material is provided.

  According to the steel sheet for concrete form according to claim 1, the steel sheet is reinforced by the reinforcing material, and thereby the spread of the steel sheet due to the lateral pressure generated at the time of placing concrete is suppressed. In addition, the anchoring effect that the concrete is fixed to the steel plate through the reinforcing material by embedding the reinforcing material in the concrete is obtained, as a result, the adhesion strength of the concrete to the steel plate is improved and the integration of both is promoted, The strength of the housing is improved.

  The steel plate according to claim 1, wherein the reinforcing material is a reinforcing bar, and includes a plurality of reinforcing bars fixed to the steel plate so as to extend in the horizontal direction and / or the vertical direction along the inner surface. (Claim 2). In addition, the reinforcing material is in a rod shape or a plate shape, and includes a form in which the reinforcing material is fixed to the inner surface in a state of standing on the inner surface.

  Next, the steel sheet for concrete formwork according to claim 4 of the present invention is a steel sheet used as a permanent formwork of concrete by combining a plurality when combining or reinforcing a concrete frame. A rib formed at an end of the main plate portion, wherein the rib protrudes inward from the main plate portion and a second protrusion further protrudes inward from the first protrusion portion. It is characterized by having.

  According to the steel sheet for concrete formwork according to claim 4, the steel sheet is reinforced by the ribs, and thereby the spread of the steel sheet due to the lateral pressure generated during the concrete placing is suppressed. Moreover, the anchor effect by a rib is acquired because a rib is embed | buried in concrete, As a result, the adhesion strength of the concrete with respect to a steel plate improves, integration of both is accelerated | stimulated, and the intensity | strength improvement of a housing is achieved. In particular, since the rib has the second projecting portion, the movement of the concrete in the direction away from the inner surface of the steel plate is prevented, and the integration of the concrete and the steel plate is firmly held.

  5. The steel plate according to claim 4, wherein the first protruding portion is bent and protruded at a substantially right angle with respect to the main plate portion, and the second protruding portion is bent and protruded at a substantially right angle with respect to the first protruding portion. (Claim 5).

  According to the present invention, the spread of the steel plate due to the side pressure generated during the placement of the concrete is suppressed, and the strength of the frame is improved by improving the adhesion strength of the concrete to the steel plate and promoting the integration of both. There exists an effect that the steel plate for formwork is provided.

It is a side view which shows the pillar which is a housing concerning one Embodiment of this invention. It is a partially broken side view of the pillar of one Embodiment. It is a cross-sectional view of the pillar of one Embodiment. It is a cross-sectional view which shows the column steel plate unit of one Embodiment, Comprising: (a) shows the case where a column steel plate is U shape, (b) shows the case where a column steel plate is L shape. It is sectional drawing which shows the vertical rib of the column steel plate of one Embodiment, Comprising: (a) The state where the vertical ribs contact | abut directly, (b) The state which pinched | interposed the viscoelastic member between the vertical ribs is shown. It is sectional drawing which shows the horizontal rib of the column steel plate of one Embodiment, Comprising: (a) The state which the horizontal rib contact | abuts directly, (b) The state which pinched | interposed the viscoelastic member between horizontal ribs is shown. It is a perspective view which shows the inner side of the pillar steel plate of one Embodiment. It is a perspective view of the pillar steel plate of other embodiments. It is a perspective view of the pillar steel plate of other embodiment.

  FIG. 1 shows a pillar 1 that is a frame constructed using a steel sheet for concrete formwork according to an embodiment of the present invention. Hereinafter, the structure after construction of the pillar 1 and the construction method for obtaining the structure will be described.

[1] Column Structure As shown in FIGS. 2 and 3, the column 1 has a square cross section, and a permanent column mold 1A in which a plurality of column steel plate units 10 are stacked from the bottom to the top. The reinforcing steel bar 100 for reinforcement extending vertically is arranged inside and the concrete C is placed. The reinforcing bar rod 100 is provided in the vicinity of the inner surface of the columnar frame 1A and extends vertically, and a plurality of reinforcing bars 102 that are fastened to the outside of the main bars 101 at equal intervals in the vertical direction. Consists of

  As shown in FIG. 4A, the column steel plate unit 10 constituting the column mold 1A is a combination of a plurality of column steel plates (concrete steel plates) 11 having a shape corresponding to the outer shape of the column 1. A fiber sheet F is wound around and coated on the entire outer surface of the column steel plate 11. The column steel plate 11 is mainly composed of a main plate portion 12 formed in a U-shape by bending two portions on both ends in the longitudinal direction of a rectangular steel plate material at right angles to the same direction. By making both ends face each other, they are combined into a square box shape in plan view that opens in the vertical direction corresponding to the cross-sectional shape of the rectangular column.

  The dimensions of the pillar steel plate 11 are appropriately set according to the dimensions of the pillar 1. For example, a steel sheet having a thickness of about 1.6 to 3.2 mm and a vertical height of about 300 to 600 mm is used. As shown to Fig.5 (a), the longitudinal rib 8 which protrudes inside is formed in the both ends side edge of the width direction (horizontal direction) of the main board part 12 in the column steel plate 11 over the full length of the side edge part. Yes. Moreover, as shown to Fig.6 (a), the horizontal rib 9 which protrudes inside is formed in the up-and-down edge of the column steel plate 11 over the full length of these edges.

  The vertical ribs 8 are formed to protrude from the main plate portion 12 by being bent at right angles to the inside, and the second protrusion portions 82 are formed to be bent at a right angle from the first protrusion portion 81 to be protruded. Is a two-stage bent structure. On the other hand, the horizontal rib 9 has a similar two-stage bent structure, and is bent at a right angle inward from the main plate portion 12 and is bent at a right angle further inward from the first protrusion 91. And a second projecting portion 92 formed.

  The protrusions 81, 82, 91, 92 of the vertical rib 8 and the horizontal rib 9 are formed by bending the end portion of the main plate portion 12. The width of the vertical rib 8 and the horizontal rib 9 is, for example, about 20 to 100 mm. The width of each of the protrusions 81, 82, 91, and 92 is slightly larger than the second protrusions 82 and 92 in the illustrated example. It is not limited, and is set appropriately as necessary.

  As shown in FIGS. 3 and 7, a plurality of reinforcing bars 51 are fixed to the inner surface 13 of the main plate portion 12 of the pillar steel plate 11 along the inner surface 13. The reinforcing bar 51 is obtained by bending a straight material reinforcing bar at a right angle. In this case, the reinforcing bar 51 extends in parallel with the width direction of the column steel plate 11 and has a length over both ends of the inner surface 13 of the main plate portion 12. A plurality of wires are fixed to the inner surface 13 by means such as spot welding at equal intervals in the vertical direction. The reinforcing bar 51 has an outer diameter protruding from the inner surface 13. The diameter of the reinforcing bar 51 is appropriately washed. For example, a diameter of about 10 to 25 mm is used.

  When the column steel plate unit 10 is configured by combining the two column steel plates 11 in a box shape, the first protrusions 81 of the vertical ribs 8 are brought into direct contact with each other, and this state can be slid by a clip or the like. Temporarily fix to the extent and keep the joined state.

  The steel plate 11 shown in FIGS. 3, 4 (a), and 7 is formed in a U shape, and the steel plate unit 10 is composed of a pair of two steel plates, but as shown in FIG. 4 (b). In addition, the column steel plate 11 may be L-shaped, and the column steel plate unit 10 may be configured by assembling the four steel plates 11 into a cross-sectional shape of the column 1 in one set. Also in the case of such an L-shaped column steel plate 11, the longitudinal rib 8 having the first projecting portion 81 and the second projecting portion 82, and the lateral rib 9 having the first projecting portion 91 and the second projecting portion 92 are formed. At the same time, a plurality of horizontal reinforcing bars 51 are fixed to the inner surface 13 of the main plate portion 12.

  As the fiber sheet F, for example, a method in which a continuous sheet-like fiber processed into a strip shape is impregnated with an adhesive is wound while applying tension to the outer surface of the column steel plate unit 10. In this way, one long fiber sheet F can be easily stretched over the entire surface of the column steel plate unit 10, and can be bonded to the outer surface of the column steel plate 11 simultaneously with winding with the impregnating adhesive.

  Examples of the fiber material of the fiber sheet F include polyethylene, carbon, glass, vinylon, aramid, and the like, and polyethylene and carbon excellent in alkali resistance are preferable.

[2] Column Construction Method Next, a method for constructing the column 1 will be described.
As described above, the two column steel plates 11 are combined in a box shape by bringing the first protrusions 81 of the longitudinal ribs 8 at both ends into contact with each other, and the fiber sheet F is wrapped around the entire outer surface of the column steel plates 11 to cover them. A plurality of column steel plate units 10 are sequentially laminated on the floor slab of the lower floor to construct a permanent column mold 1A. When constructing the column form frame 1A, as shown in FIG. 6A, the first protrusion 91 of the horizontal rib 9 of the lower column steel plate 11 projects the first rib 91 of the upper column steel plate 11 from the first. The protrusions 91 are placed and overlapped, and the first protrusions 91 of the upper and lower horizontal ribs 9 are in direct surface contact.

  As described above, the first protrusions 91 of the lower ribs 9 of the column steel plates 11 in the upper column steel plate unit 10 are projected to the first protrusions 91 of the upper ribs 9 of the column steel plates 11 of the lower column steel plate unit 10. A plurality of column steel plate units 10 are stacked in multiple stages while the portion 91 is placed and stacked, and a permanent column mold 1 </ b> A of the column 1 is constructed. Note that the stacked columnar steel plate units 10 temporarily hold the stacked horizontal ribs 9 so as to be slidable with clips or the like, and suppress the displacement of the upper and lower column steel plate units 10.

  Further, reinforcing bar rods 100 for reinforcement are arranged in the column mold 1A. The reinforcing bar 100 is appropriately arranged together with the stacking of the column steel plate units 10, and for example, the main bar 101 is erected first and the band 102 is fastened to the main bar 101 from the bottom, or the pre-assembled reinforcing bar 100 is attached to the column mold 1A. For example, a method is adopted in which the steel plate unit 10 is dropped from above to arrange the bars, and the column steel plate units 10 are sequentially stacked around the reinforcing bar 100.

  Next, concrete C is filled and placed in the column mold 1A in which the reinforcing bar 100 is arranged, and the concrete C is cured. The concrete C contacts the inner surface 13 of the column steel plate 11, and the reinforcing bar 51 is embedded in the concrete C.

[3] Effect of Embodiment In the column 1 constructed as described above, the column steel plate 11 becomes a strength member in order to leave the column steel plate 11 as a permanent formwork, and a fiber sheet is formed on the outer surface of the column steel plate 11. Since F is bonded, various strengths such as bending resistance, shear resistance, and toughness are improved, and axial strength is improved.

  In particular, the pillar steel plate 11 is reinforced by the fact that a plurality of reinforcing bars 51 are fixed to the inner surface 13 of the main plate portion 12, thereby suppressing the outward spread due to the side pressure generated when the concrete C is placed. Further, by embedding the reinforcing bar 51 in the concrete C, an anchor effect that the concrete C is fixed to the column steel plate 11 through the reinforcing bar 51 is obtained, and as a result, the adhesion strength of the concrete C to the column steel plate 11 is improved. Integration of both is promoted, and the strength of the pillar 1 is improved.

  Further, the column steel plate 11 is also reinforced by the vertical ribs 8 and the horizontal ribs 9, and the spread of the column steel plate 11 due to the lateral pressure generated when the concrete C is placed is suppressed. Further, the vertical ribs 8 and the horizontal ribs 9 are embedded in the concrete C, so that the anchor effect by the vertical ribs 8 and the horizontal ribs 9 is obtained. As a result, the adhesion strength of the concrete C to the column steel plate 11 is improved, Integration is promoted, and the strength of the pillar 1 is improved. In particular, the presence of the second protrusion 92 in the lateral rib 9 prevents the movement of the concrete C in the direction away from the inner surface 13 of the column steel plate 11, and the integration of the concrete C and the column steel plate 11 is firmly maintained. .

  Further, when a large force is received due to an earthquake or the like, friction is generated between the contacting vertical ribs 8 and the horizontal ribs 9, and this friction force becomes a damper that suppresses vibration. For this reason, the seismic control effect against the seismic force is demonstrated as follows.

  That is, between the horizontal ribs 9, when subjected to a seismic force that shakes in the horizontal direction, the column steel plates 11 individually move in the horizontal direction or deform (called shear deformation), and the horizontal ribs 9 are relatively displaced. Thus, the first protrusions 91 rub against each other, and friction is generated between them. The frictional force in this case corresponds to the load applied from the lateral rib 9 of the upper column steel plate 11 to the rib 9 of the lower column steel plate 11, and the lower rib 9 applies the load to the upper rib 9. The load that the lower rib 9 receives is large because it is received directly from the bottom. For this reason, the frictional force against the seismic force becomes large, the frictional force becomes a damper, the movement of the steel plate 11 in the horizontal direction is suppressed, and the seismic control effect is remarkably obtained.

  On the other hand, when receiving an earthquake force that shakes in the vertical direction due to an earthquake, the column steel plates 11 move individually in the vertical direction or are deformed (the above-described shear deformation), and the vertical ribs 8 are relatively displaced and the first protrusions are caused. The portions 81 rub against each other, and friction occurs between them. The frictional force generated between the first protrusions 81 of the vertical ribs 8 that contact in this way becomes a damper, and the movement of the column steel plate 11 in the vertical direction is suppressed, and the vibration control effect is remarkably obtained.

  Further, when the vertical rib 8 and the horizontal rib 9 move together with the column steel plate 11 due to a large force due to an earthquake or the like, friction is also generated between the vertical rib 8 and the concrete C or between the horizontal rib 9 and the concrete C. This frictional force acts as a damper that suppresses vibration, and exhibits a seismic control effect against seismic force.

  In the above-described embodiment, the first protrusions 81 of the vertical ribs 8 and the first protrusions 91 of the horizontal ribs 9 are in direct contact with each other, but FIG. 5B and FIG. As shown, the viscoelastic member 6 may be sandwiched between the first protrusions 81 and between the first protrusions 8. As the viscoelastic member 6, for example, a material made of rubber such as natural rubber or synthetic rubber is used. When the viscoelastic member 6 is sandwiched between the vertical ribs 8 and the horizontal ribs 9 in this way, the viscoelastic member 6 produces a viscoelastic damper effect when receiving vibration due to an earthquake or the like, and the damping performance is effectively improved. Demonstrated. For this reason, the effect which attenuates a shake and suppresses a shake quickly, or makes a shake small is acquired.

[4] Other Embodiments The reinforcing bar 51 is an example of a reinforcing material of the present invention, and is not limited thereto. For example, even with the same reinforcing bar, a plurality of reinforcing bars 51 are fixed to the inner surface 13 of the main plate portion 12 of the column steel plate 11 at intervals in a state extending in the vertical direction (along the vertical direction) as shown in FIG. And a form in which a plurality of reinforcing bars 51 extending in the horizontal direction and the vertical direction are assembled in a lattice shape and fixed as shown in FIG. 8B.

  Further, as shown in FIG. 9 (a), a plurality of short bar-shaped reinforcing bars 52 are used as reinforcing materials, and the plurality of reinforcing bars 52 are fixed to the inner surface 13 of the column steel plate 11 at right angles with appropriate intervals. 9B, the steel plate 55 bent into a U-shape is used as a reinforcing material, and one end surface of the plurality of steel plates 55 is set up in accordance with the inner surface 13 of the main plate portion 12 of the column steel plate 11. May be fixed to the inner surface 13. The rebar 51 and the steel plate 55 protrude from the inner surface 13 of the column steel plate 11 to some extent, and the protruding length is, for example, about the width of the ribs 8 and 9.

  Moreover, the steel plate of the present invention is not limited to the construction of a pillar, and can be applied to a housing such as a pillar / beam joint where a pillar and a beam intersect, a floor slab, or a wall.

1 ... Pillar (frame)
DESCRIPTION OF SYMBOLS 1A ... Column formwork 8 ... Vertical rib 9 ... Horizontal rib 11 ... Column steel plate (steel plate for concrete formwork)
12 ... Main plate 13 ... Inner surface 51 of steel plate ... Reinforcement (reinforcing material)
52 ... Reinforcing bars (reinforcing materials)
55 ... Steel (reinforcing material)
81, 91 ... 1st protrusion part 82, 92 ... 2nd protrusion part C ... Concrete

Claims (5)

  A concrete formwork, which is a steel plate used as a permanent formwork for concrete in the construction or reinforcement of a concrete frame, wherein a reinforcing material protruding from the inner face is provided on the inner face where the concrete contacts. Steel plate.   2. The concrete mold according to claim 1, wherein the reinforcing material is a reinforcing bar, and the plurality of reinforcing bars are fixed to the steel plate in a state of extending in a horizontal direction and / or a vertical direction along the inner surface. Steel plate for frames.   The steel sheet for concrete formwork according to claim 1, wherein the reinforcing material is rod-shaped or plate-shaped, and is fixed to the inner surface so as to stand on the inner surface. A steel plate that is used as a permanent formwork for concrete by combining a plurality of them when building or reinforcing a concrete frame,
Having a main plate portion and a rib formed at an end of the main plate portion;
The steel plate for concrete formwork, wherein the rib has a first projecting portion projecting inward from the main plate portion and a second projecting portion projecting further inward from the first projecting portion.   The said 1st protrusion part bends and protrudes in the substantially right angle with respect to the said main board part, The said 2nd protrusion part is bent and protruded in the substantially right angle with respect to the said 1st protrusion part, It is characterized by the above-mentioned. The steel sheet for concrete molds as described.

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