JP2016132892A - Box-release method, and box-release device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that facilitates box-releasing and suppresses displacement while casting concrete.SOLUTION: A box-release method includes: a positioning step, in which a position to be box-released is determined on a reference surface equivalent to an inner-side surface of concrete to be box-released and on a temporary support body built around the concrete, and a fixing part is provided at the determined locations, the fixing part having a box-release member and a box-release device fixed thereon, the box-release member being with a wall and a bottom part for blocking infiltration of concrete, and the box-release device having a temporary bar that penetrates through the box-release member and the bottom part of the box-release member; an installation step for the box-release device, in which the temporary bar is penetrated through the bottom part of the box-release member, a tip of the temporary bar is fixed on the fixing part on the reference surface, and the base edge part of the temporary bar is fixed on the fixing part on the temporary support body; a concrete casting step, in which concrete is cast after installing the box-release device; and a filling step, in which the temporary bar is pulled out after elapse of prescribed time from the casting of concrete and a filler is filled in a hole in the concrete formed after the temporary bar is pulled out.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a boxing method and a boxing device.

  For example, Patent Document 1 discloses that a space for a lock bolt is formed by removing a box when lining a tunnel invert part.

JP-A-11-022390

  When placing concrete, so-called box opening is performed in order to preliminarily form openings in the concrete for installing equipment (for example, guardrails, signs, anchor bolts, lock bolts, etc.). When unboxing, there are cases where it is difficult to position and install the unboxing formwork due to obstruction of the reinforcing bars. Also, when placing concrete, the displacement (floating, moving, rotating) of the formwork for unboxing becomes a problem. In particular, when a plurality of boxes are required, or when the concrete surface that is opened and forms an opening is inclined, the above problem becomes significant.

  In view of such a problem, an object of the present invention is to provide a technique that can be easily unboxed and can suppress displacement during concrete placing.

  In order to solve the above-mentioned problems, a boxing method according to the present invention is a method for making concrete in which a temporary bar is passed through the bottom of a boxing member having a wall and a bottom for restricting the intrusion of concrete, and the tip of the temporary bar is placed. It was fixed to a reference surface corresponding to the back surface, and the base end was fixed to a temporary support.

  Specifically, the present invention performs boxing positioning on a reference surface corresponding to the inner surface of the concrete to be boxed and a temporary support constructed around the concrete. A positioning step of providing a fixed portion for fixing a box extraction device having a box extraction member having a wall and a bottom for restricting the intrusion of concrete and a temporary bar penetrating the bottom of the box extraction member, A box in which a temporary stick is passed through the bottom of the box extraction member, the tip of the temporary stick is fixed to the fixed part of the reference surface, and the base end of the temporary stick is fixed to the fixed part of the temporary support. The installation process of the unloading device, the concrete placing process of placing concrete after the installation of the unboxing device, and after the predetermined time has elapsed from the placing of the concrete, the temporary bar is pulled out, and the temporary bar is pulled out. In the concrete hole formed by Comprising a filling step of filling the Hamazai, a, is a box Bleeding.

  According to the boxing method of the present invention, the boxing position is indicated on the reference plane and the temporary support, so that the boxing device can be used without performing surveying after rebar assembly or formwork assembly. Can be easily installed. In addition, since the fixed portions are provided on the reference surface and the temporary support, it is only necessary to fix the tip end portion and the base end portion of the temporary rod to these fixed portions, respectively, and the box unloading device can be easily made. Can be installed. Further, since the boxing device is fixed at two points, that is, the tip end portion and the base end portion of the temporary stick, it is possible to suppress the displacement (floating, moving, rotating) of the boxing device at the time of placing the concrete.

  The boxing method according to the present invention can be widely used in civil engineering work and building construction where so-called boxing is required. In the present invention, unboxing means that the opening is formed in the concrete so that the opening is not filled with concrete when placing concrete. Examples of the opening include an opening for installing equipment (for example, a guard rail, a sign, an anchor bolt, a lock bolt, a window, an entrance / exit). The reference plane varies depending on the concrete to be placed. For example, when placing roadbed concrete, the surface of invert concrete serves as a reference plane. The reference surface may be the surface of a formwork, the surface of a crushed stone after rolling, the surface of a natural ground or the ground. The fixed portion of the reference surface may be capable of restricting movement of the tip portion of the temporary stick on the reference surface. The fixed portion of the reference surface can be constituted by a concave portion, for example. The fixed portion of the reference surface may be capable of restricting the movement of the tip of the temporary stick in the axial direction of the temporary stick. The fixed portion of the temporary support body restricts the movement of the base end portion of the temporary rod. Temporary supports need only be able to fix the base end of the temporary stick, and may be newly provided to fix the temporary stick. For example, a formwork assembled for placing concrete is used. It may be.

  Here, in the filling step, the temporary bar may be pulled out before the hydration reaction of the placed concrete is settled. By pulling out the temporary bar before the hydration reaction of the placed concrete is settled and filling the concrete hole formed by pulling out the temporary bar, the water tightness of the concrete can be secured. .

  The boxing method according to the present invention further includes a reinforcing bar assembling step for assembling the concrete reinforcing bars, and in the reinforcing bar assembling step, the boxing device is arranged so that the boxing device and the reinforcing bar to be installed are not buffered. You may make it assemble a reinforcing bar using the parameter | index apparatus for confirming an installation position.

  The indicator device can be constituted by, for example, a rod-shaped member having at least the same length as the temporary rod. In addition, when the surface of the concrete to be boxed is inclined and the reference surface and the surface of the concrete to be placed are not parallel, the indicator device includes a bar-like or planar base portion placed on the reference surface, It can be set as the structure provided with the base part and a rod-shaped member extended in the direction orthogonal to the surface of the concrete which unboxes. Thereby, the position of the boxing device to be installed can be grasped. As a result, it is possible to suppress buffering between the boxing device to be installed and the reinforcing bars.

  Here, the present invention can be specified as a boxing device. For example, the present invention is a box pulling member having a wall and a bottom for restricting the intrusion of concrete, and a temporary stick that passes through the bottom of the box pulling member and is pulled out after a predetermined time has passed since placing the concrete to be boxed. And a temporary rod including a distal end portion fixed to a fixed portion of a reference surface corresponding to the back surface of the concrete and a base end portion fixed to the fixed portion of the temporary support. A device for unboxing.

  According to the boxing device of the present invention, an opening can be easily formed in concrete. The box extraction member forms an opening so that the concrete to be placed does not go around when the concrete is placed. The shape and dimensions of the box extraction member can be appropriately designed according to the equipment installed in the opening.

  The tip of the temporary bar can be tapered. Thereby, a temporary bar can be easily extracted from concrete.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which can be easily boxed and can suppress the displacement at the time of concrete placement can be provided.

FIG. 1: shows the top view of the roadbed concrete with which the installation was constructed | assembled by the boxing method which concerns on embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 3 shows a construction flow diagram of the boxing method according to the embodiment. FIG. 4: shows sectional drawing of the state before the construction start of the boxing method which concerns on embodiment. FIG. 5 shows a plan view of a state where a fixing hole is constructed in invert concrete and a mold frame and a temporary frame are assembled. FIG. 6 shows a cross-sectional view of a state where a fixing hole is constructed in invert concrete and a mold frame and a temporary frame are assembled. FIG. 7 shows a cross-sectional view of the rebar assembled state. FIG. 8 shows an enlarged perspective view of the mounting bracket. FIG. 9 shows a cross-sectional view of a state in which the boxing device is installed. FIG. 10 is a perspective view of the boxing device according to the embodiment. FIG. 11 shows a cross-sectional view of a state in which roadbed concrete is placed. FIG. 12 shows a cross-sectional view of the state where the temporary bar is pulled out. FIG. 13 shows a cross-sectional view of a state in which the non-shrink mortar is filled. FIG. 14 shows a cross-sectional view of a state in which the formwork is dismantled and the temporary frame is removed. FIG. 15 is a perspective view of the boxing device according to the first modification. FIG. 16 is a perspective view of the boxing device according to the second modification.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, as a boxing method according to the present invention, an opening for installing the equipment 3 so as to be orthogonal to the surface of the roadbed concrete 2 is provided in the roadbed concrete 2 whose surface provided on the invert concrete 1 is inclined. The case of forming will be described as an example. However, the embodiment described below is an example for carrying out the present invention, and the present invention is not limited to the mode described below.

<Overall configuration>
FIG. 1: shows the top view of the roadbed concrete with which the installation was constructed | assembled by the boxing method which concerns on embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG. The roadbed concrete 2 is provided on the invert concrete 1 and the surface is inclined. The equipment 3 is installed so as to be orthogonal to the inclined surface of the invert concrete 1. An opening 4 for installing the anchor bolt 31 of the equipment 3 is formed in the roadbed concrete 2. In the boxing method according to the present embodiment, the opening 4 for installing the anchor bolt 31 is constructed.

<Construction method>
FIG. 3 shows a construction flow diagram of the boxing method according to the embodiment. Moreover, FIGS. 4-14 shows explanatory drawing corresponding to a construction flow.

First, in step S01, the position of the unboxing part is positioned on the horizontal surface of the inverted concrete 1, and further, the fixing hole 11 is constructed in the positioning part. FIG. 4: shows sectional drawing of the state before the construction start of the boxing method which concerns on embodiment. FIG. 5 shows a plan view of a state where a fixing hole is constructed in invert concrete and a mold frame and a temporary frame are assembled. FIG. 6 shows a cross-sectional view of a state where a fixing hole is constructed in invert concrete and a mold frame and a temporary frame are assembled. Step S01 corresponds to the positioning process of the present invention. The location of the unboxed part is determined by hitting a ground ink on the surface of the invert concrete 1 based on surveying. It is only necessary to be able to specify the installation position of the fixing hole 11, that is, the position where the tip 511 of the temporary stick 51 of the boxing device 5 contacts (see FIG. 9), and the positioning may be performed by a method other than ink. The fixing hole 11 is an example of the fixed portion of the reference surface of the present invention, and is constructed by cutting a cylindrical hole on the surface of the invert concrete 1. The fixing hole 11 only needs to have a diameter that can accommodate the tip portion 511 of the temporary stick 51 and a depth that can restrict movement in the horizontal direction. A spiral groove may be formed on the inner wall surface of the fixing hole 11 by embedding a nut or a plastic cone in the fixing hole 11. In this case, by forming a spiral groove in the tip portion 511 of the temporary stick 51, the movement of the temporary stick 51 in the axial direction can be restricted, and the temporary stick 51 can be fixed to the invert concrete 1 more firmly. it can.

  In step S01, the mold 6 and the temporary frame 7 are assembled. The formwork 6 is plate-shaped, and is disposed, for example, facing the width direction so as to surround the periphery of the roadbed concrete 2 to be placed. The temporary frame 7 is an example of a temporary support body according to the present invention, and includes a column member 71 and horizontal members (first horizontal member 72 and second horizontal member 73). The column members 71 are arranged to face each other in the width direction of the roadbed concrete 2, and a plurality of column members 71 are arranged at intervals in the longitudinal direction of the roadbed concrete 2. The first horizontal member 72 is disposed along the longitudinal direction of the roadbed concrete 2, and is connected to the column member 71 at the upper and lower portions of the column member 71. The second horizontal member 73 is disposed along the width direction of the roadbed concrete 2 and is connected to the upper portion of the column member 71. In addition, the dotted line in sectional drawing corresponding to FIG. 6 and FIG. 6 shows the surface 21 of the roadbed concrete 2 to be laid. In the present embodiment, the surface 21 of the roadbed concrete 2 is inclined, and the second horizontal member 73 is connected to the column member 71 so as to be parallel to the surface 21 of the inclined roadbed concrete 2. The column member 71 and the horizontal member (the first horizontal member 72 and the second horizontal member 73) are made of an H-shaped steel material (shown in a simplified manner in the figure), but other steel materials such as a C-shape are used. May be. Further, wood or the like may be used instead of the steel material.

  In step S02, the reinforcing bar 8 is assembled. FIG. 7 shows a cross-sectional view of the rebar assembled state. Step S02 corresponds to the reinforcing bar assembly process of the present invention. In assembling the reinforcing bar 8, an indexing device 9 for confirming the installation position of the boxing device 5 is used so that the boxing device 5 (the box extraction member 52 and the temporary bar 51) and the reinforcing bar 8 are not buffered. . The indicator device 9 is connected to an L-shaped base portion 91 placed on the surface of the inverted concrete 1 as a reference surface, and both ends of the L-shaped base portion 91, and is orthogonal to the surface 21 of the roadbed concrete 2. And a rod-like portion 92 extending in the direction of the movement. The rod-shaped portion 92 has a length that reaches the second horizontal member 73 from the surface of the inverted concrete 1, and is connected to the base portion 91 so that the rod-shaped portion 92 and the horizontal portion 911 of the base portion 91 have an angle α. Has been. The angle α corresponds to the inclination angle of the surface 21 of the roadbed concrete 2. The tip of the rod-shaped portion 92 (location connected to the horizontal portion 911 of the base portion 91) is aligned with the fixing hole 11, and the indicator device 9 is inverted so that the rod-shaped portion 92 and the base portion 91 are along the width direction of the roadbed concrete 2. By placing on the surface of the concrete 1, the installation position of the box extraction device 5, that is, the installation positions of the box extraction member 52 and the temporary bar 51 can be confirmed. As a result, the reinforcing bar 8 can be assembled so as not to interfere with the boxing device 5 (the boxing member 52 and the temporary bar 51).

In step S02, the indicator device 9 is used to check the fixing position of the base end portion 512 of the temporary stick 51, that is, the fixing position of the temporary stick 51 and the second horizontal member 73. Here, FIG. 8 shows an enlarged perspective view of the mounting bracket. In consideration of the installation position of the boxing device 5, a U-shaped mounting bracket 74 that fixes the proximal end portion 512 of the temporary bar 51 is welded to the second horizontal member 73 in advance. The mounting bracket 74 according to the present embodiment is an example of a fixed portion of the temporary support body of the present invention. One straight line portion is welded to the second horizontal member 73 and the other straight line portion facing the temporary bar 51 is attached. The base end part 512 of this is connected. By using the indicator device 9, the fixing position of the base end portion of the temporary stick 51, that is, the fixing position of the temporary stick 51 and the second horizontal member 73 can be confirmed. In addition, the attachment metal fitting 74 is good also as a structure which has an annular part which lets the base end part 512 of the temporary stick 51 pass, for example. In the present embodiment, the mounting bracket 74 is welded to the second horizontal member 73 in advance. However, positioning is performed using the indicator device 9 and the mounting bracket 74 is welded to the positioned portion. Good.

  In step S03, the box extraction device 5 including the box extraction member 52 and the temporary stick 51 is installed. FIG. 9 shows a cross-sectional view of a state in which the boxing device is installed. FIG. 10 is a perspective view of the boxing device according to the embodiment. Step S03 corresponds to the boxing installation process of the present invention. The boxing device 5 includes a cylindrical boxing member 52 and a temporary bar 51 that passes through the center of the bottom 521 of the boxing member 52. The box removing member 52 has an inner diameter and a depth that can accommodate the anchor bolt 31 used for installing the equipment 3. In the present embodiment, the box extraction member 52 has a cylindrical wall, but the cross-sectional shape may be other shapes such as a quadrangle. A bottom 521 is formed at one end of the box removal member 52, and a temporary bar 51 having a circular shape in cross section passes through the center of the bottom 521 so as to be freely inserted and removed. The tip 511 of the temporary bar 51 has a tapered shape so that it can be easily pulled out from the roadbed concrete 2. The leading end portion 511 of the temporary stick 51 is inserted into the fixing hole 11 and fixed, and the base end portion 512 of the temporary stick 51 is fixed to the mounting bracket 74, whereby the boxing device 5 is installed. For fixing the base end portion 512 of the temporary bar 51 and the mounting bracket 74, a wire or a wire can be used. In addition, when a spiral groove is formed on the inner wall surface of the fixing hole 11, the spiral groove may be formed on the peripheral surface of the tip portion 511 of the temporary bar 51. Thereby, fixing force can be improved and the displacement at the time of placing the roadbed concrete 2 can further be suppressed.

  In step S04, the roadbed concrete 2 is placed. Step S04 corresponds to a part of the filling step of the present invention. FIG. 11 shows a cross-sectional view of a state in which roadbed concrete is placed. The roadbed concrete 2 is placed in an area other than the boxing device 5 inside the mold 6 so that the surface 21 is inclined.

  In step S05, the temporary stick 51 is pulled out. FIG. 12 shows a cross-sectional view of the state where the temporary bar is pulled out. Step S05 corresponds to a part of the filling step of the present invention. The temporary stick 51 is pulled out before the hydration reaction of the placed roadbed concrete 2 is settled. As a result, a space is formed inside the box removal member 52 and the hole 41 is formed by pulling out the temporary stick 51.

  In step S06, the non-shrink mortar 10 is filled in the hole 41 formed by pulling out the temporary stick 51. FIG. 13 shows a cross-sectional view of a state in which the non-shrink mortar 10 is filled. Instead of the non-shrink mortar 10, for example, a grout material may be used.

  In step S07, the mold 6 is disassembled and the temporary frame 7 is moved. FIG. 14 shows a cross-sectional view of a state in which the formwork is dismantled and the temporary frame is removed. The temporary frame 7 can be used by moving to an adjacent work area without dismantling. Of course, the temporary frame 7 may be disassembled.

  Thus, each step of the boxing method according to the embodiment is completed. Thereafter, the anchor bolt 31 can be fixed by inserting the anchor bolt 31 into the box removing member 52 and filling the periphery with mortar or grout material. By connecting the equipment 3 to the anchor bolt 31, the installation work of the equipment 3 is completed (see FIGS. 1 and 2).

<Effect>
According to the boxing method according to the embodiment described above, the boxing position is indicated on the surface of the invert concrete 1 and the second horizontal member 73. Therefore, after assembling the reinforcing bars 8 and assembling the formwork 6, The boxing device 5 can be installed without performing surveying. When the surface 21 of the roadbed concrete 2 is inclined as in the present embodiment, it is difficult to position and install the boxing device 5 with the conventional method, but according to the boxing method according to the embodiment. Can be easily unboxed. Further, the boxing device 5 only needs to fix the distal end portion 511 to the fixing hole 11 provided on the surface of the inverted concrete 1 and fix the proximal end portion 512 to the mounting bracket 74. Therefore, the boxing device 5 can be easily installed. In addition, since the boxing device 5 is fixed at the two points of the tip end portion 511 and the base end portion 512 of the temporary stick 51, the displacement (floating, moving, rotating) of the boxing device 5 at the time of placing concrete. ) Can be suppressed.

  Moreover, since the temporary stick 51 is pulled out before the hydration reaction of the roadbed concrete 2 is settled, and the hole 10 formed by the temporary stick 51 being pulled out is filled with the non-shrink mortar 10, the watertightness of the roadbed concrete 2 is increased. Sex can be secured. As a result, the strength of the roadbed concrete 2 can be ensured. Moreover, since the front-end | tip part 511 of the temporary stick 51 of the box extraction apparatus 5 is a taper shape, the temporary stick 51 can be pulled out easily.

  Further, when the reinforcing bar 8 is assembled, the installation position of the boxing device 5 to be installed can be grasped by using the indicator device 9. As a result, it is possible to suppress buffering between the boxing device 5 to be installed and the reinforcing bars 8.

  Although the preferred embodiments of the present invention have been described above, the present invention can be implemented by combining the embodiments as much as possible.

  In the embodiment, the case of boxing (forming an opening) with respect to the roadbed concrete 2 has been described, but the boxing method according to the present invention is widely used in civil engineering work and building work where so-called boxing is required. be able to. Examples of the opening formed by unboxing include an opening for installing equipment such as a guard rail, a sign, an anchor bolt, a lock bolt, a window, and an entrance. In the embodiment, the fixing hole 11 is constructed on the surface of the invert concrete 1. However, for example, when placing concrete on the mold, a plastic cone is connected to the mold and the temporary stick 51 is attached to the plastic cone. The tip 511 may be fixed.

  Further, in the embodiment, the temporary frame 7 is assembled, and the mounting bracket 74 is welded to the second horizontal member 73. However, wood is handed over and fixed to the upper end of the opposite mold 6, and the mounting bracket 74 is attached to the wood. You may make it connect.

  Further, as shown in FIG. 15, a box extraction member 52 a having a quadrangular cross section may be used instead of the cylindrical box extraction member 52. FIG. 15 is a perspective view of the boxing device according to the first modification. In the boxing device 5a according to the first modification, the cross-sectional shape of the boxing member 52a is a quadrangle. More specifically, the box removing member 52a includes four walls 522a and a bottom 521a continuous with the lower ends of the four walls 522a. The four walls 522a are respectively connected to a rectangular wall and both ends of the rectangular wall, a pair of walls in which a part of a rectangular corner is cut out into a quadrangle so that the opening side is narrow and the bottom side is wide. Of the end portions of the wall, the end portion is connected to the end portion on the opposite side of the rectangular wall, and is configured by a wall having a step. The box pulling member 52a according to Modification 1 has a step formed in a part of the wall 522a, and the area of the square opening is smaller than the area of the square bottom 521a. For example, when an opening for an anchor bolt is formed, the opening of the box may be narrower than the inner side of the box. The box removing member 52 can be appropriately designed according to the equipment. By designing the box removal member 52 according to the facility, the amount of filler to be filled can be optimized.

  Further, as shown in FIG. 16, instead of the cylindrical box removing member 52, a box removing member 52a having a quadrangular cross section and penetrating the two temporary bars 51 through the bottom 521b may be used. . FIG. 16 is a perspective view of the boxing device according to the second modification. In the boxing device 5b according to the second modification, the boxing member 52b is configured by four walls 522b and a bottom 521b connected to the lower ends of the four walls 522b. And the box extraction member 52b is comprised so that the two temporary sticks 51 can penetrate the bottom 521b.

DESCRIPTION OF SYMBOLS 1 ... Invert concrete 11 ... Fixing hole 2 ... Subbase concrete 3 ... Equipment 31 ... Anchor bolt 4 ... Opening 5 ... Box extraction device 51 ... Temporary stick 52・ ・ ・ Box extraction member 511 ・ ・ ・ Tip portion 512 ・ ・ ・ Base end portion 6 ・ ・ ・ Form frame 7 ・ ・ ・ Temporary frame 71 ・ ・ ・ Column member 72 ・ ・ ・ First horizontal member 73 ・ ・ ・Second horizontal member 74 ... Mounting bracket 8 ... Reinforcing bar 9 ... Indicator device 91 ... Base part 92 ... Rod-like part 10 ... Non-shrink mortar

Claims (5)

The boxing is positioned on the reference surface corresponding to the inner surface of the concrete to be unboxed and the temporary support constructed around the concrete, and the concrete is infiltrated into the positioned location. A positioning step of providing a fixed part for fixing a box extraction device having a box extraction member having a wall and a bottom to be controlled and a temporary bar penetrating the bottom of the box extraction member;
Passing a temporary stick through the bottom of the box removal member, fixing the tip of the temporary stick to the fixed part of the reference surface, and fixing the base end of the temporary stick to the fixed part of the temporary support; Installation process of the boxing device;
After installing the boxing device, a concrete placing process for placing concrete;
After a predetermined time has elapsed from the placement of the concrete, a filling step of pulling out the temporary bar and filling a filler into a concrete hole formed by pulling out the temporary bar;
Including unboxing method.   The boxing method according to claim 1, wherein in the filling step, the temporary bar is pulled out before the hydration reaction of the placed concrete is settled. Further comprising a rebar assembling step of assembling the concrete rebar,
The reinforcing bar is assembled in the reinforcing bar assembling step by using an index device for confirming an installation position of the boxing device so that the boxing device and the reinforcing bar to be installed are not buffered. Boxing method. A box-extracting member having a wall and a bottom for restricting the intrusion of concrete; and
A temporary stick that passes through the bottom of the boxing member and is pulled out after a predetermined time has passed since placing the concrete to be boxed, and is fixed to a fixed portion of a reference surface that corresponds to the back surface of the concrete. A box unloading device comprising: a tip end portion and a temporary bar including a base end portion fixed to a fixed portion of a temporary support. The boxing device according to claim 4, wherein a tip portion of the temporary bar has a tapered shape.

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