JP2010053579A - Perforation formation instrument, skin material holding member, and perforation forming method of concrete structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a skin material holding member which can form a through hole of various lengths in a concrete structure using a low-cost material. <P>SOLUTION: The end-holding member 11 used with a bending sleeve member 41 is provided with a contact surface 13, a plurality of stop nails 14, a boss part 16, a surface 17 to be pressed, a holding surface 20, and a cylindrical wall 21. The contact surface 13 can be brought into contact with the formwork member 61 of the concrete, and the stop nails 14 are arranged with its sharp-pointed section faced toward the formwork member 61 side. A through hole 15 into which a screw rod 51 can be inserted is formed in the boss part 16, and the surface 17 to be pressed can be pressed with a nut 52 attached to the screw rod 51. The holding surface 20 holds the end of the bending sleeve member 41 from inside, and the cylindrical wall 21 is formed in a shape to cover the outside of the end of the bending sleeve member 41. Then a notch 22 through which the end of the bending sleeve member 41 can pass is formed on the cylindrical wall 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention mainly relates to a covering material holding member for forming a through hole for piping in a concrete structure.

  Patent document 1 discloses the through-hole formation instrument for forming a through-hole in a concrete structure. This through-hole forming device includes a support rod having sharp portions attached to both ends. One sharp portion is slidable and is configured to be fixed with a push screw. The other sharp part is provided with a threaded expansion / contraction part.

When attaching the through-hole forming instrument of Patent Document 1 to the mold, the support bar is rotated. Then, the threaded expansion / contraction part is stretched and stretched, and the sharp parts at both ends bite into the formwork material to be in a fixed state. Thereafter, the core member is constructed by attaching the base member to both ends and the center of the support rod and further attaching a quarter-shaped outer shell member from the outside. In this state, the through hole can be formed by pouring concrete into the mold.
JP-A-1-105866

In addition, although the outer shell member of patent document 1 becomes a structure which cannot deform | transform, patent document 2 and 3 disclose the structure which forms a through-hole by hold | maintaining the bendable sleeve material, for example.
JP 2002-285701 A JP 2004-257227 A

  However, the configuration of Patent Document 1 has to use a support rod having a special configuration that can be expanded and contracted and has sharp portions attached to both ends, which causes a significant increase in cost. Moreover, although the length of the through hole to be formed in the concrete structure varies, it is necessary to prepare many types of support rods according to the change in the length, which reduces workability and costs. It was the cause.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a covering material holding member capable of forming various through-holes of a length in a concrete structure using a low-cost material. It is in.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to the 1st viewpoint of this invention, the following structures in the skin material holding member used with a skin material in order to form a through-hole in a concrete structure are provided. That is, the outer skin material holding member includes a contact surface, a plurality of sharp portions, an insertion portion, a pressed surface, a holding surface, and a cylindrical wall. The contact surface can contact a concrete formwork. The sharp part is arranged with a sharp part facing the formwork material side. An insertion hole into which a screw rod can be inserted is formed in the insertion portion. The pressed surface can be pressed by a female screw body attached to the screw rod. The holding surface holds the end portion of the deformable outer skin material from the inside. The said cylinder wall is formed so that the outer side of the edge part of the said outer_layer | skin material may be covered. The cylindrical wall is formed with a notch through which an end of the outer skin material can pass.

  With this configuration, the outer shell material holding member is pressed against the formwork material via the pressed surface and the outer skin is pierced into the formwork material by a simple operation of rotating the female screw body attached to the screw rod. The material holding member can be strongly fixed. In addition, since a highly versatile and easily available screw rod can be used, the cost can be effectively reduced. Furthermore, since the threaded rod can be easily cut to a desired length at the construction site, it is easy to obtain a threaded rod corresponding to the length of the through hole to be formed. In addition, since the outer skin material can be attached after first positioning (fixing) the screw rod and the outer skin material holding member, it is not necessary to position a heavy object and workability is improved. Furthermore, the outline of a through-hole can be easily formed by introduce | transducing an outer_layer | skin material from a notch part and sending it along a holding surface and a cylinder wall. Further, since the outer skin material holding member is fixed by a plurality of sharp portions, it is possible to prevent the outer skin material holding member from rotating when the outer skin material is fed. Furthermore, since the end side of the outer skin material can be covered with a cylinder wall, even if some irregularities are formed on the edge when the outer skin material is cut to a desired size, it is difficult to form a gap, and the intrusion of concrete Can be prevented satisfactorily.

  In the outer skin material holding member, it is preferable that an attachment hole to which a sharp member can be attached is disposed at a position farther from the sharp portion as viewed from the insertion hole.

  With this configuration, the rotation of the outer skin holding member can be more reliably prevented by the pointed member. This configuration is particularly suitable when it is desired to form a large-diameter through hole (when the outer skin holding member has a large diameter), and the sharp portion arranged near the center is insufficiently stopped. .

  According to the 2nd viewpoint of this invention, the skin material holding member of the following structures used with the said skin material holding member is provided. That is, the outer skin material holding member includes a main body, a first holding surface, a second holding surface, and a protruding portion. The main body is formed with a recess that can be attached to the middle portion of the screw rod in the longitudinal direction. The first holding surface is disposed on the outer periphery of the main body in order to hold the end portion of the skin material from the inside. The second holding surface is disposed on the outer periphery of the main body in order to hold an end portion of the outer skin material different from that held by the first holding surface from the inside. The protruding portion protrudes at a position between the first holding surface and the second holding surface.

  With this configuration, since a plurality of skin materials can be easily connected using the skin material holding member, it is possible to easily form long through holes in the concrete structure while suppressing an increase in the size of the skin material.

  According to the 3rd viewpoint of this invention, the through-hole formation method of a concrete structure including the following processes is provided. That is, in the first step, at least two female screw bodies are attached to the screw rod. In the second step, each of the two skin material holding members is inserted into a screw rod through an insertion hole formed in the skin material holding member. In the third step, the screw rod and the skin material holding member are positioned between the concrete formwork members arranged facing each other. In the fourth step, the outer thread material holding member is pressed against the end side of the screw rod by moving the female screw body to bring the outer skin material holding member into contact with the formwork material, and the outer skin material A plurality of sharp portions arranged on the holding member are pierced into the formwork material. In the fifth step, an end portion of the deformable skin material is introduced from the outside of the cylindrical wall and inserted between the holding surface formed on the outer skin material holding member and the cylindrical wall.

  By this method, with a simple operation of rotating the female thread body of the screw rod, the outer skin material holding member is pressed firmly against the formwork material, and the outer skin material holding member is firmly fixed by piercing the formwork material with a plurality of sharp parts. Can do. In addition, since a highly versatile and easily available screw rod can be used, the cost can be effectively reduced. Furthermore, since the threaded rod can be easily cut to a desired length at the construction site, it is easy to obtain a threaded rod corresponding to the length of the through hole to be formed. In addition, since the outer skin material can be attached after first positioning (fixing) the screw rod and the outer skin material holding member, it is not necessary to position a heavy object and workability is improved. Furthermore, the outline of the through hole can be easily formed by introducing the end portion of the outer skin material from the outside of the cylinder wall and inserting it between the holding surface and the cylinder wall. In addition, since the skin material holding member is fixed by a plurality of sharp portions, it is possible to prevent the skin material holding member from rotating when the skin material is inserted. Furthermore, since the end side of the outer skin material can be covered with a cylinder wall, even if some irregularities are formed on the edge when the outer skin material is cut to a desired size, it is difficult to form a gap, and the intrusion of concrete Can be prevented satisfactorily.

  Next, embodiments of the invention will be described. FIG. 1 is a cross-sectional perspective view showing in detail an end holding member 11 according to an embodiment of the present invention.

  The end holding members 11 and 11 as the skin material holding members shown in FIG. 1 are used as a pair in order to form a through hole in a concrete structure. The pair of end holding members 11, 11 have the same configuration.

  Each end holding member 11 includes a main body 12 formed into a disk shape by, for example, a synthetic resin. A flat contact surface 13 that can come into contact with a concrete mold material is formed on the surface of the main body 12 on one side in the thickness direction.

  A plurality of pegs (sharp portions) 14 protrude from the contact surface 13. The peg 14 is integrally formed so as to be embedded in the main body 12.

  A through hole (insertion hole) 15 into which the screw rod 51 can be inserted is formed at the center of the main body 12 formed in a disc shape. The pegs 14 are arranged at equal intervals in the vicinity of an opening formed in the contact surface 13 by the through hole 15.

  A cylindrical boss portion (insertion portion) 16 is formed at the center of the surface of the main body 12 opposite to the contact surface 13. The boss portion 16 is formed so as to protrude in a direction away from the contact surface 13. The through hole 15 is formed so as to penetrate the boss portion 16, and an opening is formed on the end surface of the boss portion 16.

  A flat pressed surface 17 that can be pressed by a nut (a female screw body) 52 attached to the screw rod 51 is formed on the tip surface of the boss portion 16 and around the opening. Radial ribs 18 for reinforcement are formed around the boss portion 16. In the present embodiment, three ribs 18 are arranged side by side at equal intervals in the circumferential direction.

  An annular insertion groove 19 is formed on the surface of the main body 12 opposite to the contact surface 13. The insertion groove 19 is formed so as to open the side opposite to the contact surface 13.

  Of the pair of inner walls facing in the radial direction inside the insertion groove 19, a holding surface 20 capable of holding a bent sleeve material to be described later is formed on the inner wall. On the other hand, a cylindrical tube wall 21 is formed on the radially outer side of the insertion groove 19. The cylindrical wall 21 is formed with one notch 22 having an appropriate size.

  A plurality of elongated attachment holes 23 are formed in the main body 12 so as to penetrate therethrough. The mounting hole 23 is configured such that an auxiliary nail described later can be inserted. The mounting hole 23 and the peg 14 are arranged at positions corresponding to the ribs 18.

  In order to form a lateral through hole in a concrete structure using the end holding member 11 having the above configuration, first, a screw rod 51 having an appropriate length is prepared, and two nuts 52 are attached to the screw rod 51. Keep it. The threaded rod 51 is a so-called “dimension” long bolt, which is generally used at the construction site and can be easily obtained, and can be used after being cut to a desired length. .

  Then, the pair of end holding members 11, 11 are arranged so that the contact surfaces 13 (pegs 14) face each other, and the end of the screw rod 51 is inserted into the through hole 15. Thereby, the end holding member 11 can be supported on both ends of the screw rod 51. The pair of end holding members 11 and 11 are attached to the screw rod 51 in a state in which the positions of the notches 22 are aligned as shown in FIG.

  Next, as shown in FIG. 2, the screw rod 51 and the end holding members 11, 11 are inserted from above into the wooden formwork members 61, 61 arranged to face each other to form a concrete structure. Place with. A reinforcing bar (not shown) is arranged inside the mold members 61, 61, but the screw rod 51 is adjusted to be slightly shorter than the distance between the mold members 61, 61 facing each other. Thus, the screw rod 51 and the end holding members 11 and 11 can be easily arranged so as to pass between the reinforcing bars.

  Next, in a state where the screw rod 51 and the end holding member 11 are arranged at desired positions, the nut 52 is rotated and moved to the end side of the screw rod 51. Then, as shown in FIG. 3, the nut 52 that moves by the screw presses the pressed surface 17 of the end holding member 11, so that the end holding member 11 is pushed toward the formwork material 61, and the retaining nail 14 becomes the formwork material. The contact surface 13 comes into contact with the formwork 61 while being pierced by 61. In addition, since the nail 14 is disposed in the vicinity of the through hole 15, the pressing force from the nut 52 can be transmitted straight to the nail 14, and the fixing failure due to the bending of the nail 14 or the like can be prevented. Can do.

  The screw rod 51 and the end holding member 11 can be reliably positioned by the projecting action of the screw rod 51 and the end holding member 11 and the piercing of the nail 14. Further, since the positioning can be performed only by inserting a tool such as a spanner from above and rotating the nut 52, the workability is good. When the through hole formed in the concrete structure has a large diameter, an auxiliary nail 55 as a pointed member is provided inside the mounting hole 23 in order to secure the end holding member 11 (non-rotating). The auxiliary nail 55 may be driven into the end holding member 11 and the mold member 61 using a hammer or the like.

  Next, as shown in FIG. 4, the intermediate holding member 31 is attached to the center of the screw rod 51. The intermediate holding member 31 includes a center tube 32 formed in a C shape, a cylindrical outer tube 33 disposed outside the center tube 32, and a plurality of spoke portions that connect the center tube 32 and the outer tube 33. 34 are integrally formed. The spoke portions 34 are formed so as to extend radially from the center tube 32, and three spoke portions 34 are arranged at equal intervals.

  The outer diameter of the outer cylinder 33 is configured to coincide with the diameter of the holding surface 20 of the end holding member 11. In addition, an oblique cut 35 is formed in the outer cylinder 33 at a position corresponding to the open portion of the central cylinder 32. Therefore, by appropriately elastically deforming the outer cylinder 33, the interval between the notches 35 can be increased as shown in FIG. Thereafter, the intermediate holding member 31 can be supported on the central portion of the screw rod 51 by inserting the screw rod 51 from the open side of the C-shaped center tube 32.

  Next, as shown in FIG. 5, a bent sleeve material (outer skin material) 41 is inserted between the frame members 61, 61 from the upper side and arranged around the screw rod 51. As shown in FIG. 5, the bent sleeve material 41 is formed in a shape in which a large number of elongated rod-like members having a trapezoidal cross section are arranged in a row and connected to each other. It can be bent over a range of angles. The bent sleeve material 41 is formed of a synthetic resin and can be cut into a desired size by using a cutter knife or the like.

  Hereinafter, the process of inserting the bent sleeve material 41 will be specifically described. That is, the bent sleeve material 41 cut in advance so as to be slightly shorter than the interval between the mold materials 61 is inserted into the mold materials 61 and 61 from above, and both ends of the bent sleeve material 41 are held at the respective ends. It passes through the notch 22 of the member 11. Then, the bent sleeve material 41 is fed in the circumferential direction along the annular insertion groove 19 while being wound around the outer cylinder 33 of the intermediate holding member 31.

  As described above, as shown in FIG. 6, the bent sleeve material 41 can be arranged so as to cover the periphery of the screw rod 51, and the outline of the through hole can be formed. In this way, the bending sleeve material 41 can be formed into a cylindrical shape by guiding the annular insertion groove 19 (the holding surface 20 and the cylindrical wall 21) simply by feeding the bending sleeve material 41 from the upper side into the notch 22. Therefore, workability is very good.

  Finally, a staple-like connecting body 43 is driven into the joint portion 42 of the bent sleeve material 41 to connect the ends. In this state, ready-mixed concrete is placed inside the mold member 61. In addition, it is possible to satisfactorily prevent the ready-mixed concrete from entering the bent sleeve material 41 by closing the joint portion 42 and the cutout portion 22 with a tape or the like in advance. After the concrete is hardened, a cylindrical through hole can be formed by removing the end holding member 11, the intermediate holding member 31, the bending sleeve material 41, the screw rod 51, and the like.

  As described above, the end holding member 11 of this embodiment used together with the bending sleeve material 41 to form a through hole in a concrete structure has a contact surface 13, a plurality of pegs 14, and a boss portion 16. And a pressed surface 17, a holding surface 20, and a cylindrical wall 21. The contact surface 13 is configured to be able to contact a concrete formwork 61. The peg 14 is arranged with a sharp portion facing the formwork 61 side. A through hole 15 into which the screw rod 51 can be inserted is formed in the boss portion 16. The pressed surface 17 can be pressed by a nut 52 attached to the screw rod 51. The holding surface 20 holds the end of the deformable bent sleeve material 41 from the inside. The cylindrical wall 21 is formed so as to cover the outer side of the end of the bent sleeve material 41. The cylindrical wall 21 is formed with a notch 22 through which the end of the bent sleeve material 41 can pass.

  Moreover, in this embodiment, the through-hole is formed in the concrete structure by the following processes. That is, in the first step, the two nuts 52 are attached to the screw rod 51. In the second step (FIG. 1), each of the two end holding members 11 is inserted into the screw rod 51 through the through hole 15 formed in the end holding member 11. In the third step (FIG. 2), the screw rod 51 and the end holding member 11 are positioned between the concrete formwork members 61 arranged facing each other. In the fourth step (FIG. 3), each end holding member 11 is pressed against the end of the screw rod 51 by moving the nut 52 by screw, and the end holding member 11 is brought into contact with the formwork member 61. The plurality of pegs 14 arranged on the end holding member 11 are pierced into the mold material 61. In the fifth step (FIG. 5), the end of the deformable bending sleeve material 41 is introduced from the outside of the cylindrical wall 21 between the holding surface 20 formed on the end holding member 11 and the cylindrical wall 21. Plug in.

  Accordingly, the end holding member 11 is pressed against the formwork material 61 through the pressed surface 17 and a plurality of pegs 14 are pierced into the formwork material 61 by a simple operation of rotating the nut 52 of the screw rod 51. Thus, the end holding member 11 can be strongly fixed. Moreover, since the screw rod 51 which is highly versatile and easily available can be used, the cost can be effectively reduced. Furthermore, since the screw rod 51 can be easily cut to a desired length at the construction site, it is easy to obtain the screw rod 51 corresponding to the length of the through hole to be formed. Further, since the bent sleeve material 41 can be attached after the screw rod 51 and the end holding member 11 are first positioned (fixed), it is not necessary to position a heavy object, and workability is improved. Furthermore, by introducing the bent sleeve material 41 from the outside of the cylindrical wall 21 through the notch 22 and feeding it along the holding surface 20 and the cylindrical wall 21, the outline of the through hole can be easily formed. Further, since the end holding member 11 is fixed by the plurality of pegs 14, it is possible to prevent the end holding member 11 from rotating when the bending sleeve material 41 is fed. Furthermore, since the end portion side of the bending sleeve material 41 can be covered with the cylindrical wall 21, even if some unevenness is formed when the bending sleeve material 41 is cut into a desired size, it is difficult to form a gap, and concrete. Can be prevented well.

  Further, in the end holding member 11 of the present embodiment, the attachment hole 23 to which the auxiliary nail 55 can be attached is disposed at a position farther than the retaining nail 14 when viewed from the through hole 15.

  Thereby, the rotation of the end holding member 11 can be more reliably prevented by the auxiliary nail 55. This configuration is particularly suitable when it is desired to form a large-diameter through hole (when the end holding member 11 has a large diameter), and when the retaining nail 14 disposed in the vicinity of the center is insufficiently rotated. It is.

  Next, a modification for forming a long through hole in a concrete structure will be described with reference to FIGS. FIG. 7 is a schematic perspective view showing a state where the connection holding member 36 is attached to the screw rod 51. In this modification, the same or similar members as those in the above embodiment may be denoted by the same reference numerals in the drawings, and the description thereof may be omitted.

  FIG. 7 shows one end side of the long screw rod 51, and the end holding member 11 having the same configuration as that of the above embodiment is attached to the one end. Although not shown in FIG. 7, the end holding member 11 is also attached to the other end of the screw rod 51.

  A connection holding member 36 is attached to the middle portion of the screw rod 51 in the longitudinal direction. The configuration of the connection holding member 36 is similar to that of the intermediate holding member 31, and includes a double cylindrical main body 37 including a center tube 32, an outer tube 33, and a spoke portion 34. The center tube 32 is configured in a C shape, and is formed with a recess that can be attached to the middle portion of the screw rod 51 in the longitudinal direction.

  An annular projecting wall (projecting portion) 40 is formed on the outer peripheral surface of the outer cylinder 33 so as to divide the outer peripheral surface into two in the longitudinal direction of the screw rod 51. One outer peripheral surface divided into two is a first holding surface 38, and the remaining outer peripheral surface is a second holding surface 39. Each of the two holding surfaces 38 and 39 is configured to be able to hold separate bent sleeve materials 41 from the inside.

  In the modification shown above, when the bending sleeve material 41 is arranged around the screw rod 51, as shown in FIG. 8, one bending sleeve material 41 is connected to the end holding member 11 and the connection holding member 36 (first holding member 36). It is attached between the holding surface 38), and another bent sleeve material 41 is attached between the connection holding member 36 (second holding surface 39) and the end holding member 11 on the other side. Thereby, it can hold | maintain, connecting the some bending sleeve material 41, and can form a long through-hole.

  If it is desired to form a longer through-hole, a plurality of connection holding members 36 may be attached to the screw rod 51 at appropriate intervals, and three or more bent sleeve members 41 may be connected and held. it can. Since the bending sleeve material 41 can be easily connected and used in this manner, the bending sleeve material 41 can be made compact in advance, and transportation on site, handling of work, etc. can be improved.

  As described above, in this modification, the connection holding member 36 includes the main body 37, the first holding surface 38, the second holding surface 39, and the protruding wall 40. The central tube 32 provided in the main body 37 is formed with a recess that can be attached to the middle portion of the screw rod 51 in the longitudinal direction. The first holding surface 38 is disposed on the outer periphery of the main body 37 in order to hold the end of the bent sleeve material 41 from the inside. The second holding surface 39 is disposed on the outer periphery of the main body 37 in order to hold the end portion of the bending sleeve material 41 different from that held by the first holding surface 38 from the inside. The protruding wall 40 protrudes so as to partition the first holding surface 38 and the second holding surface 39.

  Thereby, since the some bending sleeve material 41 can be easily connected using the connection holding member 36, while suppressing the enlargement of the bending sleeve material 41, a long through-hole can be easily formed in a concrete structure. .

  Although the preferred embodiments and modifications of the present invention have been described above, the above configuration can be modified as follows, for example.

  In the end holding member 11, the number of the nail 14 can be changed to, for example, two, four, or five or more instead of three as illustrated in the drawing. Moreover, the arrangement position of each peg 14 can also be changed as appropriate.

  The number of ribs 18 can be changed, for example, a cross-shaped (four) rib. Further, the arrangement position and the number of the installation holes 23 can be changed as appropriate. Further, when it is considered that fixing with the nail 14 is sufficient, such as when a small-diameter through hole is formed, the mounting hole 23 for the auxiliary nail 55 can be omitted.

  In the above-described embodiment, the nut 52 is configured as a hexagonal nut, but can be changed to a female screw body having another configuration.

  The number of installed intermediate holding members 31 can be changed as appropriate. Moreover, when forming a through-hole with a short length, it can also change so that the bending sleeve material 41 may be attached in the state which does not attach the intermediate | middle holding member 31 to the screw rod 51. FIG.

  In the state in which the intermediate holding member 31 or the connection holding member 36 is first attached to the screw rod 51, the screw rod 51 and the end holding member 11 can be changed between the mold materials 61.

  In the connection holding member 36 of the above modification (FIG. 8), a weakened portion such as a perforation may be formed at the base of the protruding wall 40. In this case, after the concrete is solidified (even when the bent sleeve material 41 is left in the hole), the protruding wall 40 is separated from the main body 37 of the connection holding member 36 by pulling the connection holding member 36 in the axial direction. The body 37 can be easily pulled out of the hole and removed.

  Moreover, in the said connection holding member 36, it can replace with forming the protruding wall 40 continuously in the circumferential direction, and can change into the structure which arranges several small protrusions at intervals in the circumferential direction. In this case, by deforming the protrusions, the connection holding member 36 can be easily removed from the hole after solidifying the concrete, as described above.

The cross-sectional perspective view which shows the edge part holding member which concerns on one Embodiment of this invention in detail. Side surface sectional drawing which shows a mode that it arrange | positions inside the formwork material of concrete in the state which attached the edge part holding member to the screw rod. Side surface sectional drawing which shows a mode that an edge part holding member is fixed to a formwork material by rotating a nut. The model perspective view which shows a mode that an intermediate | middle holding member is mounted | worn with a screw rod. The model perspective view which shows a mode that a bending sleeve material is attached to an edge part holding member. The model perspective view which shows a mode that the circumference | surroundings of the screw rod were covered with the bending sleeve material. The model perspective view which shows a mode that the connection holding member was mounted | worn with the screw rod in the modification in the case of forming a long through-hole. The schematic perspective view which shows a mode that a bending sleeve material is attached to an edge part holding member and a connection holding member.

Explanation of symbols

11 End holding member (skin material holding member)
13 Contact surface 14 Peg (sharp part)
15 Through hole (insertion hole)
16 Boss part (insertion part)
17 Pressed surface 20 Holding surface 21 Cylindrical wall 22 Notch 23 Mounting hole 51 Screw rod 52 Nut (Female thread)
55 Auxiliary nails (pointers)

Claims (4)

A skin material holding member used together with a skin material to form a through hole in a concrete structure,
A contact surface capable of contacting a concrete formwork;
A plurality of sharp portions arranged with a sharp portion facing the mold material side;
An insertion part in which an insertion hole into which a screw rod can be inserted is formed;
A pressed surface that can be pressed by a female screw attached to the screw rod;
A holding surface for holding the end of the deformable outer skin material from the inside;
A cylindrical wall formed so as to cover the outer side of the end portion of the outer skin material, and a notch portion through which the end portion of the outer skin material can pass,
An outer skin material holding member comprising: The outer skin holding member according to claim 1,
An outer skin material holding member, wherein an attachment hole to which a sharp member can be attached is disposed at a position farther from the sharp portion as viewed from the insertion hole. A skin material holding member used together with the skin material holding member according to claim 1 or 2,
A body formed with a recess that can be attached to the middle portion of the screw rod in the longitudinal direction;
A first holding surface disposed on the outer periphery of the main body in order to hold the end portion of the outer skin material from the inside;
A second holding surface disposed on the outer periphery of the main body in order to hold an end portion of the outer skin material different from that held by the first holding surface from the inside;
A protruding portion protruding at a position between the first holding surface and the second holding surface;
An outer skin material holding member comprising: A first step of attaching at least two female screw bodies to the screw rod;
A second step of inserting each of the two skin material holding members into a screw rod through an insertion hole formed in the skin material holding member;
A third step of positioning the screw rod and the skin material holding member between the concrete formwork material arranged facing each other;
By screw-moving the female screw body, the respective skin material holding members are pressed against the end portions of the screw rods, the skin material holding members are brought into contact with the formwork material, and are arranged on the skin material holding members. A fourth step of piercing the formwork material with a plurality of sharp portions,
A fifth step of introducing and inserting an end portion of the deformable skin material from the outside of the cylindrical wall between the holding surface formed on the outer skin material holding member and the cylindrical wall;
The through-hole formation method of a concrete structure characterized by including this.

Images