JP2005097855A - Concrete plate member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concrete plate member which mainly bears a shearing force, wherein the plate member comprises a single steel plate exerting two-way reinforcement, to thereby achieve thinning of a minimum thickness of the member. <P>SOLUTION: The concrete plate member is for use as a precast web or the like arranged between upper and lower floor slabs of a main girder of a bridge. According to the structure of the precast web, a single or a plurality of perforated steel plates 11 having a plurality of rows of holes 12 bored therein, are embedded in a plate main body 10 in layers in a manner being sandwiched by concrete 13. Further, arrangement of a plurality of longitudinal and transverse steel bands A, B between the holes, achieves the two-way reinforcement of the steel plate, and by virtue of a slippage preventive function of the holes 12, the steel plates and the concrete are integrated into one body. Furthermore the perforated steel plate has its ends 11a, 11b protruded outward from the plate main body 10, and the ends thus protruded are embedded in the upper and lower floor slabs in one body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a concrete flat plate member which mainly receives a shearing force, and is applied to, for example, a bridge superstructure web.

  In the reinforcement of the flat plate member to which the in-plane shearing force acts, the reinforcing bars are arranged so as to intersect in two vertical and horizontal directions. FIG. 3 shows an example in which a precast web is used as the web 4 disposed between the upper and lower floor slabs 2 and 3 of the box girder 1 as a bridge superstructure. Conventionally, as shown in FIG. 4, an axial rebar 50 and a stirrup 51 as a shear reinforcing bar are arranged inside the precast web 4, and connecting rebars 52 and 53 are provided at the upper and lower ends, respectively. The upper and lower ends of the precast web 4 are joined and integrated with the upper floor slab 2 and the lower floor slab 3, respectively. Moreover, the PC steel material 54 of the vertical direction is arrange | positioned in the cross-sectional center, and the prestress is provided.

  Further, in a beam member on which a bending moment and a shearing force act, as a reinforcing bar for the bending moment, a reinforcing bar is arranged in a direction perpendicular to the shearing force, and a shearing reinforcing bar is arranged in parallel to the shearing force.

In any case of the precast web and the beam member, the reinforcing bars are arranged in two vertical and horizontal directions.

  Moreover, about the reinforcement of the concrete member using a perforated steel plate, there exists an example proposed as reinforcement of only one direction with respect to the bending moment of a floor slab (refer patent document 1). In this invention, a plurality of strip-shaped steel plates having a plurality of holes are embedded in the floor slab body, strength is obtained with a steel plate integrated with concrete through the holes, and the steel plate ends protruding from the end surface of the floor slab body are mutually connected. By joining, adjacent floor slab bodies are joined together.

Further, as technical documents related to the present invention, there are a concrete panel (see Patent Document 2) in which a perforated plate is embedded, and a precast concrete board (see Patent Document 3) in which a lightweight steel reinforcing material is embedded as a reinforcing rib.
JP-A-11-350431 Japanese Utility Model Publication No. 06-16543 Japanese Patent Laid-Open No. 06-93679

  When reinforcing bars are arranged vertically and horizontally as described above, the thickness of the reinforcing bars needs to be twice as thick as the diameter of the reinforcing bars, so the minimum thickness required for construction is increased and the member thickness is made as thin as possible. It becomes an obstacle to make a rational structure.

  Moreover, in the example which reinforce | strengthened with respect to the bending of one direction of a floor slab using a perforated steel plate like invention of patent document 1, it is not effective arrangement | positioning in two directions.

  The present invention has been made to solve such problems, and in a flat plate member mainly subjected to shearing force, it is possible to reinforce in two directions with a single steel plate, and to reduce the minimum thickness of the member. An object of the present invention is to provide a concrete flat plate member.

  Claim 1 of the present invention is a concrete flat plate member on which shearing force mainly acts, and a porous steel plate in which a plurality of rows of holes are drilled is embedded in layers so as to be sandwiched between concrete in the flat plate body. It is a concrete flat plate member characterized by these. This 1st aspect is a case where it uses as a shear reinforcement of the general precast panel member which receives a shearing force.

  According to a second aspect of the present invention, in the concrete flat plate member according to the first aspect, the end of the perforated steel plate protruding outside from the flat plate body is embedded and integrated in the adjacent concrete member. It is a flat plate member. The second aspect of the present invention is, for example, a case where it is used as a shear reinforcement for a precast web of a bridge box girder, and a perforated steel plate having a plurality of rows of holes formed in a precast web provided between upper and lower floor slabs of a bridge main girder. Are embedded in layers so as to be sandwiched between concrete in the flat plate main body, and the ends of the perforated steel plates protruding outside from the flat plate main body are embedded and integrated in the upper and lower floor slabs.

  A third aspect of the present invention is the concrete flat member according to the first or second aspect, wherein a plurality of perforated steel plates are disposed at intervals in the plate thickness direction of the flat plate body. It is a flat plate member. By using a plurality of perforated steel sheets, a thin and high strength concrete flat plate member is obtained. Further, for example, in the case of using reinforcement with PC steel material, a plurality of perforated steel plates can be disposed so as to sandwich the PC steel material. It is preferable to connect the porous steel plates with a connecting member or the like.

  A number of holes in the perforated steel sheet of the present invention are arranged at intervals in the vertical direction and the horizontal direction to form a two-dimensional array, and a plurality of steel strips are present between the holes in the vertical direction and the horizontal direction.

  According to the present invention configured as described above, a plurality of steel strips exist between the holes in the perforated steel sheet in the longitudinal direction and the transverse direction, so that a single steel sheet can be reinforced in two directions. The minimum thickness of the member can be reduced. Moreover, since the hole functions as a stopper, the steel plate and the concrete can be integrated. Furthermore, the thickness of the steel plate itself can be made smaller than the rebar diameter by appropriately setting the interval between the holes. Further, by joining the porous steel plate to the outside from the flat plate main body to be a joining end portion and embedding the joining end portion in a member to be joined, joining and integration can be performed with a relatively simple structure. If a plurality of perforated steel plates are arranged, a thin flat concrete plate member with high strength can be obtained. If a plurality of perforated steel plates are arranged so as to sandwich the PC steel material, a high strength concrete flat plate member can be obtained. If the porous steel plates are connected to each other, the concrete inside can be constrained to further increase the proof stress.

  Since this invention consists of the above structures, there exist the following effects.

  (1) Since a plurality of rows of holes are perforated, and there are a plurality of steel strips in the vertical and horizontal directions between the holes in the porous steel plate embedded in layers so as to be sandwiched between concrete in the flat plate body, A single steel plate can be reinforced in two directions, the minimum thickness of the concrete flat plate member can be reduced, and the hole functions as a stopper, so that the steel plate and the concrete can be integrated.

  (2) By appropriately setting the interval between the holes, the thickness of the steel plate itself can be made smaller than the diameter of the reinforcing bar, and the thickness can be further reduced.

  (3) Bonding and integration can be performed with a relatively simple structure by causing the porous steel plate to protrude from the flat plate body to a joining end portion and burying the joining end portion in a member to be joined.

  (4) If a plurality of perforated steel sheets are arranged, a thin and strong concrete flat plate member can be obtained. Moreover, if a PC steel material is arrange | positioned so that it may be pinched | interposed between several porous steel plates, and a prestress will be provided, a still higher concrete flat plate member will be obtained. If the porous steel plates are connected to each other, the concrete inside can be constrained to further increase the proof stress.

  Hereinafter, the present invention will be described based on the illustrated embodiments. In this embodiment, the present invention is applied to a box girder web of a bridge. FIG. 1 shows an embodiment in which the concrete flat plate member of the present invention is applied to a web of a bridge box girder.

  The embodiment of FIG. 1 is a case where it is used as a shear reinforcement for a precast web of a bridge box girder, and a perforated steel plate 11 having a plurality of rows of holes 12 drilled in a concrete flat plate body 10 is used as left and right concrete 13, 13. It embeds in layers so that it may be pinched | interposed and it is set as the precast flat plate (panel) member, ie, the precast web 4. FIG.

  The upper part of the perforated steel plate 11 protrudes upward from the concrete flat plate body 10 to form a joining end 11a, is embedded in the upper floor slab 2 of FIG. 3, and the upper part of the perforated steel plate 11 is joined and integrated with the upper floor slab 2. The lower end of the perforated steel plate 11 is bent in an L-shape, etc., so that the joining end portion 11b made of perforated steel plate protrudes horizontally and is embedded in the lower floor slab 3 of FIG. 3 to be integrated.

  The holes 12 are arranged so as to be aligned in a straight line in the vertical direction and the horizontal direction so that a plurality of steel strips A and B between the holes exist in the vertical and horizontal directions. At least one row of holes 12 is arranged in the joint end 11a and the joint end 11b. The arrangement of the holes 12 is not limited to the illustrated example, and may be a staggered arrangement. Further, the shape, diameter, pitch (opening ratio), and the like of the holes 12 can be appropriately selected.

  If it is only reinforced with a porous steel plate against the shearing force, the number of the porous steel plate 11 may be one. In that case, the porous steel plate 11 can make a panel thin.

  If reinforcement with PC steel is used in combination, two porous steel plates 11 are preferably arranged. If the porous steel plates 11 and 11 are connected by a connecting member, the concrete inside can be constrained to further increase the yield strength.

  FIG. 2 shows an embodiment in which two perforated steel plates and a PC steel material are used. The PC steel material 14 is disposed at the center of the cross section of the concrete flat plate body 10, and the two perforated steel plates 11 are sandwiched between the PC steel materials 14. Arrange as follows. Further, the upper and lower end portions of the PC steel material 14 and the two porous steel plates 11 are projected from the upper and lower end surfaces of the concrete flat plate body 10 by a predetermined length, and the upper joint end portions 11a and 14a are embedded in the upper floor slab 2, The joining end portions 11 b and 14 b are embedded in the lower floor slab 3.

  In FIG. 2, unlike FIG. 1, the concrete 3 a and the lower floor slab rebar 3 b of the lower floor slab 3 are extended to just below the precast web 4, and the lower part of the perforated steel plate 11 is projected in a plane. In addition, also when the number of the perforated steel plates 11 in FIG. 1 is one, it is possible to perform the same joining as in FIG. When it is bent in an L shape, it takes time to produce the panel, but it is easy to construct the lower floor slab on site, and conversely, if it is left flat, it is easy to produce the panel. However, it takes time to construct the lower floor slab.

  Since a single perforated steel sheet 11 can be reinforced in two directions, not only can the minimum thickness of the member be reduced, but the thickness of the perforated steel sheet itself can be reduced by setting the interval between the holes appropriately. Can be made smaller. For example, when a steel plate having a thickness of 6 mm is used, if the hole diameter is 50 mm and the distance between the holes is 50 mm, this corresponds to the amount of steel material in which reinforcing bars having a diameter of 19 mm are arranged at a pitch of 100 mm. Moreover, since the hole 12 functions as a stopper (perforated steel plate gibber), the porous steel plate 11 and the concrete 13 can be integrated. Further, by embedding the joint end portion 11a and the joint end portion 11b made of a porous steel plate in the concrete of the upper floor slab 2 and the lower floor slab 3, joint integration can be achieved with a relatively simple structure.

  In addition, although the example which applied this invention to the web of the box girder of a bridge was shown above, it cannot be overemphasized that this invention can be applied not only to this but to the concrete flat member to which a shearing force mainly acts.

It is a perspective view which shows one Embodiment at the time of applying the concrete flat plate member of this invention to the web of the box girder of a bridge. It is a vertical sectional view which shows other embodiment at the time of applying the concrete flat plate member of this invention to the web of the box girder of a bridge. It is a partial section perspective view showing an example of a box girder of a bridge using a precast web. The example of the conventional precast web is shown, (a) is a vertical sectional view, (b) is a horizontal sectional view.

Explanation of symbols

1 …… Box girder 2 …… Upper floor slab 3 …… Lower floor slab 4 …… Precast web 10 …… Concrete flat plate body 11 …… Perforated steel plate 12 …… Hole 13 …… Concrete 14 …… PC steel material A …… Steel material Belt (vertical direction)
B: Steel strip (lateral direction)

Claims (3)

  A concrete flat plate member in which a shearing force mainly acts, wherein a porous steel plate having a plurality of rows of holes formed therein is embedded in layers so as to be sandwiched between concrete in a flat plate body.   The concrete flat plate member according to claim 1, wherein an end portion of the porous steel plate protruded from the flat plate body to the outside is embedded and integrated in an adjacent concrete member.   The concrete flat plate member according to claim 1 or 2, wherein a plurality of perforated steel plates are arranged at intervals in the plate thickness direction of the flat plate main body.

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