JP2012012812A - Construction method of nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a nut to be buried in a rising part of a reinforced concrete structure, allowing the nut to be accurately arranged at a prescribed burying position.SOLUTION: A formwork 14A has an open hole at a position corresponding to a burying position of a high nut after burying. In a nut holding step, a holding bolt is screwed in the high nut from outside through the open hole, so as to accurately hold the high nut at the prescribed burying position. Since the high nut is fixed to the formwork 14A with the holding bolt, the high nut is held at a proper position in a casting step without being swept away by concrete.

Description

  The present invention relates to a method for constructing a nut embedded in a rising portion of a reinforced concrete structure and into which a bolt is screwed.

  There are cases where other members of different materials are fixed with bolts to the rising part of the reinforced concrete structure, for example, the wall of the reinforced concrete structure, the rising part of the cloth foundation, or the like. Specifically, a store signboard or a steel support arm of a cantilever balcony may be fixed to the rising portion. As a construction method applied to such a structure, for example, those described in Patent Document 1 and Patent Document 2 are known.

  Patent Document 1 describes a method of inserting a chemical anchor or the like into a hole formed after forming a rising surface at a rising portion, and driving a bolt to fix it. Patent Document 2 describes a construction method in which a nut is previously held on a reinforcing bar by a binding wire or the like, and then concrete is placed.

JP 2003-147785 A JP 2000-248557 A

  However, the following problems occur in the conventional method as described above. That is, the construction method according to Patent Document 1 has a problem that it is difficult to set the bolt at an accurate position because it is difficult to perform drilling work with high accuracy on a hard rising portion made of concrete. It was. Moreover, in the construction method according to Patent Document 2, there is a problem that the position of the nut is shifted when installing the formwork, or the position of the nut is shifted due to the flow of concrete when placing concrete. Furthermore, there is a problem that it is difficult to confirm and correct the position of the nut by being closed by the mold.

  The present invention has been made to solve such a problem, and provides a method for constructing a nut capable of accurately arranging a nut embedded in a rising portion of a reinforced concrete structure at a predetermined embedded position. The purpose is to do.

  The nut construction method according to the present invention is a nut construction method embedded in a rising part of a reinforced concrete structure, and has a through hole at a position corresponding to the nut embedding position in the rising part, A mold placement step in which a mold for forming the rising portion is arranged, and a bolt is inserted into the through hole from the outside of the mold and the bolt is screwed into the nut, so that the nut is placed in the embedded position. It is characterized by having a nut holding step to be held, a placing step for placing concrete to form a rising portion, and a removing step for removing bolts and molds.

  According to the nut construction method of the present invention, the formwork for forming the rising portion has a through hole formed at a position corresponding to the embedded position of the nut after being embedded. The through-hole formed in the mold can ensure high positional accuracy and greatly increase the work load compared to the hole formed by drilling work on the solid concrete part at the rising part. Can be reduced. In the nut holding step, the nut can be accurately held at a predetermined embedded position by screwing the bolt into the nut from the outside through the through hole. Furthermore, since the nut can be fixed to the formwork by the bolt, the nut can be held at an appropriate position without being poured into the concrete even in the placing process. After the predetermined curing period, when the bolt and the formwork are removed in the removing process, the nut is kept in an accurate position in the rising portion. As described above, the nut embedded in the rising portion can be accurately placed at the predetermined embedded position.

  Further, in the nut construction method according to the present invention, there are a plurality of nuts, a plurality of nuts are connected by a fixing bracket, and the step of fixing the fixing bracket to a position inside the rising portion is a stage before the nut holding step. It is preferable to have. In this way, in the previous stage of the nut holding process, by fixing the fixing metal fitting for connecting a plurality of nuts at a position inside the rising portion, in the previous stage of screwing the bolt into the nut, Alignment can be performed. This facilitates the work of screwing the bolt into the nut. Furthermore, since a plurality of nuts are fixed to the fixing bracket, the nut holding step and the placing step can be performed in a state where the relative positional relationship between these nuts is accurately held. Therefore, the position accuracy of the nut can be further improved as compared with the case where each nut is simply fixed with a mold via a bolt. Furthermore, after the placement, the fixing bracket is embedded in the rising portion, so that even when a pulling force acts on the nut, the fixing bracket functions as an anchor to counter the pulling force. it can. Thereby, the nut can be firmly fixed in the rising portion.

  ADVANTAGE OF THE INVENTION According to this invention, the nut embed | buried under the standing | starting-up part of a reinforced concrete structure can be arrange | positioned with a sufficient precision in a predetermined embedment position.

It is sectional drawing which showed the standup part to which the construction method of the nut which concerns on embodiment of this invention was applied, and the support arm of the balcony fixed to the said standup part. In the construction method of the nut which concerns on embodiment of this invention, it is a perspective view which shows a mode that the fixing metal fitting was fixed to the reinforcing bar. It is a perspective view which shows a mode that the formwork was arrange | positioned in the construction method of the nut which concerns on embodiment of this invention. It is the figure which looked at the mode of the process from the process in which the holding bolt is screwed into the high nut to the removal of the said holding bolt and a formwork from the upper direction in the construction method of the nut which concerns on embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a nut construction method according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a rising portion to which the nut construction method according to the present embodiment is applied, and a balcony support arm fixed to the rising portion. As shown in FIG. 1, a plurality of reinforcing bars 2 and a plurality of high nuts 3 are embedded in a rising portion 1 of a fabric foundation that is a reinforced concrete structure. In addition, the rising surface 1 a configured by the side surface extending in the vertical direction in the rising portion 1 is covered with a plate-like heat insulating material 4. In the example shown in FIG. 1, the support arm 100 of the balcony is fixed to the rising surface 1 a of the rising portion 1 via the heat insulating material 4. The high nut 3 extends so as to be perpendicular to the rising surface 1 a in the rising portion 1. The main body of the high nut 3 is embedded at a predetermined embedded position in the rising portion 1, but one end surface of the high nut 3 is exposed from the rising surface 1a without being covered with concrete. The cantilever-like support arm 100 is fixed to the rising portion 1 by screwing bolts 101 into a plurality of high nuts 3 embedded in the rising portion 1.

  With reference to FIG.1 and FIG.2, the structure of the some high nut 3 is demonstrated in detail. FIG. 2 is a perspective view showing a state in which the fixing fitting is fixed to the reinforcing bar 2 in the nut construction method according to the embodiment of the present invention. As shown in FIG.1 and FIG.2, this embodiment demonstrates the method to embed four high nut 3A, 3B, 3C, 3D in the predetermined embedment position as the high nut 3 embed | buried. The position where the high nuts 3A, 3B, 3C, 3D are to be placed in the state where the concrete has hardened and the rising portion 1 is completed (that is, the state shown in FIG. 1) is referred to as “embedding position”, and the following explanation is given. Do. In the present embodiment, the fixture 10 having the high nuts 3A, 3B, 3C, 3D is fixed to the reinforcing bar 2, and the holding bolts are screwed into the high nuts 3A, 3B, 3C, 3D through the molds. Concrete is cast at In FIG. 1 and FIG. 2, as reinforcing bars 2, reinforcing bars (horizontal bars) 2 </ b> A and 2 </ b> B extending in the horizontal direction and reinforcing bars (vertical bars) 2 </ b> C and 2 </ b> D extending in the vertical direction are shown. The vertical bars 2C and 2D are disposed on the rising surface 1a side of the horizontal bars 2A and 2B. The vertical streak 2C and the vertical streak 2D have the same diameter, are parallel to the rising surface 1a (the inner surface of the formwork 14A), and have substantially the same distance from the rising surface 1a (that is, the vertical streak 2C and the vertical streak 2D). The surface including the material axis is parallel to the rising surface 1a). The horizontal stripes 2A and 2B may have different diameters, and even when the diameters are different, the distance between the rising surface 1a and the surfaces of the horizontal stripes 2A and 2B is the same.

  The fixture 10 includes a rectangular plate 11, studs 12A, 12B, 12C, 12D, high nuts 3A, 3B, 3C, 3D, and round bars 13A, 13B. The rectangular plate 11 is a metal plate that spreads so as to face the rising surface 1 a when embedded in the rising portion 1. The implantation bolts 12A, 12B, 12C, and 12D are bolts implanted in the four corners of the surface 11a of the plate 11, respectively. The high nuts 3A, 3B, 3C, 3D are fixed to the plate 11 by screwing the studs 12A, 12B, 12C, 12D into the rear end portion on the opposite side to the rising surface 1a. The studs 12A, 12B, 12C, and 12D are screwed to a position where the distance between the rear end of the high nuts 3A, 3B, 3C, and 3D and the plate 11 becomes a predetermined size. Fixed. The concrete bolts 12A, 12B, 12C, 12D can prevent the concrete from flowing into the high nuts 3A, 3B, 3C, 3D from the rear end side. The material nut directions of the high nuts 3 </ b> A, 3 </ b> B, 3 </ b> C, 3 </ b> D are configured to be perpendicular to the surface of the plate 11.

  The round bars 13A and 13B are fixed to the back surface 11b side of the plate 11. The round bars 13A and 13B extend in the vertical direction so as to be parallel to each other. The lower ends of the round bars 13A and 13B extend below the edge 11c on the lower end side of the plate 11. Further, the diameter of the round bars 13A and 13B is not particularly limited, but is preferably a diameter corresponding to the diameter of the reinforcing bar 2. For example, it can be made the same diameter as the vertical stripes 2C and 2D extending in the vertical direction. The diameters of the round bar 13A and the round bar 13B are the same and are preferably the same as or larger than the longitudinal bars 2C and 2D. If the round bars 13A and 13B have a smaller diameter than the vertical bars 2C and 2D, the back bar 11b and the vertical bars of the plate 11 when the round bars 13A and 13B are installed so as to straddle either the vertical bars 2C or 2D. This is because the rods 13A and 13B come into contact with either 2C or 2D, and the round bars 13A and 13B cannot be brought into contact with the horizontal bars 2A and 2B at the same time. The round bars 13A and 13B may be configured to contact three or more horizontal bars.

  Next, with reference to FIG. 2, FIG. 3, FIG. 4, the manufacturing process of the rising part 1 at the time of employ | adopting the construction method of the nut which concerns on this embodiment is demonstrated. FIG. 3 is a perspective view showing a state in which the formwork is arranged in the nut construction method according to the embodiment of the present invention. FIG. 4 is a view of the state of the process from the step of screwing the holding bolt into the high nut to the removal of the holding bolt and the formwork from above in the nut construction method according to the embodiment of the present invention. is there.

  First, general foundation works such as root cutting, local work, and reinforcement are performed. At this time, as shown in FIG. 2, a reinforcing bar 2 is formed at a position where the rising portion 1 is formed. The fixing bracket 10 is fixed to the reinforcing bar 2 (step of fixing the fixing bracket). Accordingly, the plurality of high nuts 3A, 3B, 3C, and 3D are aligned together with the plate 11. In this process, temporary alignment of the high nuts 3A, 3B, 3C, and 3D is performed, and accurate alignment is performed in a nut holding process described later. That is, since the stage shown in FIG. 3 is a stage of temporary alignment of the high nuts 3A, 3B, 3C, 3D, the position of the high nuts 3A, 3B, 3C, 3D is set to the rising portion 1 as shown in FIG. It may deviate from the embedded position inside.

  For example, as shown in FIG. 2, the fixing bracket 10 is fixed to the reinforcing bar 2 by binding a predetermined portion of the fixing bracket 10 to the reinforcing bar 2 with a binding wire CL. In the example shown in FIG. 2, the round bars 13A and 13B are fixed so as to be in contact with and supported by the horizontal bars 2A and 2B extending in the horizontal direction. By bringing the round bars 13A and 13B of the fixing bracket 10 into contact with the horizontal bars 2A and 2B, the plate 11 is parallel to the rising surface 1a, that is, the material shaft of the high nut is perpendicular to the rising surface 1a. ing. In the present embodiment, the upper ends of the round bars 13A and 13B of the fixture 10 are in contact with the horizontal bars 2A and the lower ends are in contact with the horizontal bars 2B. It is easier to maintain the state in which the plate 11 is parallel to the rising surface 1a as compared with the case where the plate 11 is brought into contact.

  Further, the lower ends of the round bars 13A and 13B extend below the lower edge 11c of the plate 11. For example, when the round bars 13A and 13B do not extend below the edge portion 11c, the lower horizontal stripes 2B are arranged below the lower edge portion 11c of the plate 11 as shown in FIG. When the fixing bracket 10 is in position, the fixing bracket 10 is supported only on the upper end side by the horizontal bars 2A, and the posture of the fixing bracket 10 becomes unstable. On the other hand, in this embodiment, since the round bars 13A and 13B extend downward and are in contact with the lower horizontal bars 2B, the upper end of the fixing bracket 10 is provided even when the horizontal bars 2A and 2B are arranged as shown in FIG. It can be supported on both the side and the bottom side. Thereby, even when the space between the horizontal stripes 2A and the horizontal stripes 2B is larger than the vertical width of the plate 11, the posture of the fixing bracket 10 can be stabilized. In addition, since the round bars 13A and 13B have the same diameter as the vertical bars 2C and 2D extending in the vertical direction, for example, a reinforcing bar extending in the vertical direction is arranged between the round bar 13A and the round bar 13B. Even in such a case, it is easy to perform alignment without the plate 11 rattling.

  Next, as shown in FIG. 3, formwork 14A, 14B for placing concrete is placed (formwork placement step). In this step, a first mold 14A for forming the rising surface 1a of the rising portion 1 and a second mold 14B for forming a side surface opposite to the rising surface 1a are arranged. Moreover, the heat insulating material 4 is arrange | positioned at the side surface inside 14 A of 1st molds. The first mold 14A and the second mold 14B may be arranged at the same time after the alignment step, or the second mold 14B is arranged before the alignment step and the first after the alignment step. A formwork 14A may be arranged. In the following description, the side where the rising portion 1 is formed is referred to as “inside” of the molds 14A and 14B, and the opposite side is referred to as “outside” of the molds 14A and 14B.

  Through holes 16A and 16B for inserting holding bolts 17A, 17B, 17C, and 17D into the first mold 14A at positions corresponding to the embedded positions of the high nuts 3A, 3B, 3C, and 3D in the rising portion 1, respectively. , 16C, 16D are formed. Specifically, the through holes 16A, 16B, 16C, and 16D are aligned with the screw holes at the ends of the high nuts 3A, 3B, 3C, and 3D that are exposed from the rising surface 1a as shown in FIG. It is formed in the position. The heat insulating material 4 also has through holes formed at positions corresponding to the through holes 16A, 16B, 16C, and 16D of the first mold 14A. The diameters of the through holes 16A, 16B, 16C, and 16D are preferably slightly larger than the diameters of the holding bolts 17A, 17B, 17C, and 17D. This is because the construction error may increase when the play is large. In addition, when it has a predetermined standard and the position of a fixed target object is determined based on the module of a building, it is preferable to prepare a dedicated formwork. The through holes 16A, 16B, 16C, 16D of the first mold 14A and the through holes of the heat insulating material 4 are formed in advance before the first mold 14A is set at a predetermined position. However, it may be performed after the first mold 14A is set at a predetermined position. The “formwork placement step” in the claims includes both cases.

  Next, as shown in FIG. 4A, holding bolts 17A, 17B, 17C, and 17D are inserted into the through holes 16A, 16B, 16C, and 16D from the outside of the first mold 14A, and the holding bolt 17A is inserted. , 17B, 17C, 17D are screwed into the high nuts 3A, 3B, 3C, 3D (nut holding process). As a result, the high nuts 3A, 3B, 3C, 3D are accurately held at the embedded positions to be disposed in the rising portion 1. At this time, if the high nuts 3A, 3B, 3C, 3D are displaced from the embedded position in the above-described alignment step, the operator moves the fixing bracket 10 to pass the high nuts 3A, 3B, 3C, 3D through the through holes. By aligning the holding bolts 17A, 17B, 17C, and 17D in accordance with the positions of 16A, 16B, 16C, and 16D, accurate positioning can be easily performed. The end portions on the rising surface 1a side of the high nuts 3A, 3B, 3C, 3D are held so as to be in contact with the inner surface of the heat insulating material 4. When the heat insulating material 4 is not disposed, the heat insulating material 4 is held in contact with the inner surface of the first mold 14A.

  Next, as shown in FIG. 4B, concrete CM is placed between the first mold 14A and the second mold 14B, and is cured for a predetermined time (placement process). As a result, the concrete is solidified in a state where the high nuts 3A, 3B, 3C, 3D are accurately held at the embedded position, and the rising portion 1 is formed. After the rising portion 1 is formed, as shown in FIG. 4C, the holding bolts 17A, 17B, 17C, 17D and the molds 14A, 14B are removed (removal process). Accordingly, the support arms 100 of the veranda as shown in FIG. 1 can be fixed using the high nuts 3A, 3B, 3C, 3D embedded in the rising portion 1.

  The operation and effect of the nut construction method according to the embodiment of the present invention will be described.

  According to the nut construction method according to the present embodiment, the first mold 14A for forming the rising portion 1 is formed at a position corresponding to the embedded position of the high nuts 3A, 3B, 3C, 3D after being embedded. The through holes 16A, 16B, 16C, and 16D are provided. The through holes 16A, 16B, 16C, and 16D formed in the first mold 14A have higher positional accuracy than holes formed by drilling a concrete portion of the rising portion 1 after curing. Can be ensured, and the work load can be greatly reduced. Further, in the nut holding step, the holding bolts 17A, 17B, 17C, 17D are screwed into the high nuts 3A, 3B, 3C, 3D from the outside through the through holes 16A, 16B, 16C, 16D. The high nuts 3A, 3B, 3C, 3D can be accurately held at the buried position. Furthermore, since the high nuts 3A, 3B, 3C, and 3D can be fixed to the first mold 14A by the holding bolts 17A, 17B, 17C, and 17D, the high nuts are not poured into the concrete even in the concrete placing process. 3A, 3B, 3C, 3D can be held at an appropriate position. After the predetermined curing period, when the holding bolts 17A, 17B, 17C, 17D and the molds 14A, 14B are removed in the detaching process, the high nuts 3A, 3B, 3C, 3D are in the correct position in the rising portion 1. The buried state is maintained. As described above, the high nuts 3A, 3B, 3C, and 3D embedded in the rising portion 1 can be accurately arranged at the predetermined embedded position.

  In the nut construction method according to the present embodiment, the high nuts 3A, 3B, 3C, and 3D are fixed to the plate 11 that spreads so as to face the rising surface 1a of the rising portion 1 in the previous stage of the nut holding step. Thus, the fixing bracket 10 is configured, and the positioning of the fixing bracket 10 is performed. Thus, by positioning the fixing bracket 10 before the nut holding step, in the stage before screwing the holding bolts 17A, 17B, 17C, 17D into the high nuts 3A, 3B, 3C, 3D, Temporary alignment of the high nuts 3A, 3B, 3C, 3D can be performed. This facilitates the screwing operation.

  Further, since the plurality of high nuts 3A, 3B, 3C, 3D are fixed to the plate 11, the nuts are maintained in a state in which the relative positional relationship between these high nuts 3A, 3B, 3C, 3D is accurately maintained. Can be held and concrete can be placed. In the present embodiment, the high nuts 3A, 3B, 3C, and 3D are held in an accurate positional relationship by the plate 11 on the inner side of the rising portion 1, and the through holes 16A of the first mold 14A on the rising surface 1a side. , 16B, 16C, and 16D are held at accurate positions by holding bolts 17A, 17B, 17C, and 17D. As a result, the high nuts 3A, 3B, 3C, 3D are reliably kept parallel to each other. From the above, it is possible to further improve the position accuracy of the nut as compared with the case where each nut is simply fixed with a mold via a bolt. With such a configuration, all the high nuts can be prevented from being displaced on the inner side only by accurately fixing the single plate 11 to the horizontal bars 2A and 2B, and the high nuts with respect to the rising surface 1a can be prevented. The material axis can be kept at a right angle. Further, for example, by inserting a holding bolt into two diagonal high nuts, the position of the other high nut can be automatically guided to a predetermined position (the position of the through hole of the first mold 14A). . Therefore, it is possible to improve the work efficiency of positioning the high nut.

  Further, the plate 11 spreads so as to face the rising surface 1a. Therefore, even when a pulling force acts on the high nuts 3A, 3B, 3C, 3D, the plate 11 embedded in the rising portion 1 functions as an anchor and can counter the pulling force. Thereby, the high nuts 3A, 3B, 3C, 3D can be firmly fixed in the rising portion 1.

  The present invention is not limited to the embodiment described above.

  For example, the method of fixing the fixing bracket 10 to the reinforcing bar 2 is not limited to that shown in FIG. 2, and can be appropriately changed depending on the configuration of the reinforcing bar 2, the fixing position, and the like. Further, the round bars 13A, 13B and the reinforcing bars 2 are fixed in contact with each other, but the high nuts 3A, 3B are made by bringing the surface 11a of the plate 11 into contact with the back side of the reinforcing bars 2 without using the round bars 13A, 13B. , 3C, 3D may extend between the reinforcing bars and extend to the rising surface 1a side. In such a fixing method, when a pulling force is applied to the high nuts 3A, 3B, 3C, 3D, the plate 11 is supported not only by the concrete but also by the rebar 2. Therefore, the high nuts 3A, 3B, 3C, 3D are It can be fixed more firmly in the rising portion 1.

  Further, the number and position of the high nuts in the fixing bracket, the size and shape of the plate, the arrangement, the length and the diameter of the round bar are not limited to the above-described embodiment, and can be changed as appropriate. The round bar may not extend below the lower edge of the plate, and the round bar itself may not be provided.

  Further, the plurality of high nuts may not be fixed by the plate, and the high nuts separated from each other may be fixed to the rebar 2 and fixed to the first mold 14A. However, also in this case, the rear end side is closed with a bolt or the like in order to prevent the concrete from flowing into the high nut. Further, the high nut may not be temporarily aligned by being fixed to the reinforcing bar 2, and the high nut may be placed in a state in which the high nut is only fixed to the first mold 14A via the holding bolt.

  The present invention is not limited to the above-mentioned buildings, but can be applied to reinforced concrete structures in general such as retaining walls and fences, but particularly in buildings where the dimensions and dimensions of each part are standardized, such as industrialized houses. It can be used suitably.

  DESCRIPTION OF SYMBOLS 1 ... Rising part, 1a ... Rising surface, 2 ... Rebar, 3, 3A, 3B, 3C, 3D ... High nut (nut), 10 ... Fixing metal fitting, 11 ... Plate, 14A, 14B ... Formwork, 16A, 16B, 16C, 16D ... through holes, 17A, 17B, 17C, 17D ... holding bolts (bolts).

Claims (2)

It is a construction method of a nut embedded in the rising part of a reinforced concrete structure,
A mold placement step in which a through hole is provided at a position corresponding to the embedded position of the nut in the rising portion, and a mold for forming the rising portion is disposed;
A nut holding step in which the bolt is inserted into the through hole from the outside of the mold and the bolt is screwed into the nut, whereby the nut is held in the embedded position;
Placing a concrete to form the rising portion; and
And a removing process for removing the bolt and the formwork. The nut is plural,
A plurality of the nuts are connected by a fixing bracket,
The method for constructing a nut according to claim 1, further comprising a step of fixing the fixing bracket at a position inside the rising portion at a stage before the nut holding step.

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