Pre-installation method for embedded metal forms and embedded metal

Abstract

To provide a form pre-attaching method for an embedded hardware, which facilitates the arrangement of the embedded hardware from the front side of a form, and eliminates the need for machining the periphery of an opening formed in the form.SOLUTION: An opening 52 is provided at a predetermined position of a plate surface constituting a form, an anchor part 12 of an embedded hardware 10 and a receiving member 14 are inserted from a side surface where concrete is not placed to a side surface where concrete is placed through the opening 52, the plate surface of a form 50 is held by the receiving member 14 and a pressing member 18, a spacer 16 blocking the opening 52 is arranged between the receiving member 14 and the pressing member 18, the embedded hardware 10 is fixed to the form 50, and a concrete 70 is placed.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a method for pre-attaching embedded formwork when pouring concrete, and in particular to a method for pre-attaching embedded metal formwork and embedded metal that are suitable when the construction space on the concrete pouring surface side is narrow. [Background technology]

[0002] Patent Document 1 discloses an example of a method for pre-installing embedded metal fittings when the formwork is close to the foundation surface and the space between the reinforcing bars is narrow, such as in tunnel lining construction. The method disclosed in Patent Document 1 involves inserting a suspension anchor, which serves as an embedded metal fitting, into the concrete pouring surface through a pouring window formed in the formwork, thereby temporarily fixing the embedded metal fitting. The suspension anchor (embedded metal fitting) disclosed in Patent Document 1 is configured with an insert section that will have an opening on the tunnel surface where the concrete is poured, and a fixing section with sides larger than the spacing between the reinforcing bars formed in a grid pattern. This method discloses that the fixing section of the suspension anchor inserted through the pouring window is positioned behind the reinforcing bars to temporarily fix the suspension anchor. After fixing the suspension anchor to the reinforcing bars, concrete is poured between the foundation surface and the formwork, and the formwork is removed after the concrete has hardened, completing the pre-installation of the embedded metal fittings.

[0003] With metal fittings (embedded fittings) embedded using this method, the anchoring points are located on the backside of the reinforcing bars and are larger than the grid size formed by the reinforcing bars, so there is no risk of the embedded fittings falling. However, when installing embedded fittings from the front side of the formwork (the side opposite the concrete pouring surface), the pouring window formed in the formwork must be at least larger than the anchoring points, which requires processing such as filling in the formwork holes when pouring concrete, and depending on the arrangement of the reinforcing bars, it may not be possible to place the embedded fittings in the desired position.

[0004] Another known technique for fixing embedded metal fittings (sockets) in place using openings (holes: pouring windows) in the formwork is to clamp the formwork using a bolt that screws into a washer and a socket, as disclosed in Patent Document 2. While this method allows the holes formed in the formwork to be small, it requires that the embedded metal fittings be placed from the back side of the formwork, making it difficult to apply when the gap between the formwork and the foundation surface is narrow, such as in the tunnel construction disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-169017 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-17317 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, the present invention aims to provide a formwork pre-attachment method for embedded metal fittings that allows for easy placement of embedded metal fittings from the front side of the formwork, has a high degree of freedom in placement, and does not require processing around the openings formed in the formwork, as well as embedded metal fittings to be used in this method. [Means for solving the problem]

[0007] The method of pre-attaching embedded metal fittings to a formwork according to the present invention, which is intended to achieve the above-mentioned objectives, involves creating an opening at a predetermined position on the surface of a plate constituting a formwork, one side of which is the side on which concrete is poured and the other side is the side on which concrete is not poured, and inserting the anchor portion of the embedded metal fitting and a receiving member that abuts the anchor portion when embedded from the other side to the one side through the opening, clamping the plate surface between the receiving member arranged on the one side and the pressing member arranged on the other side, and placing a spacer between the receiving member and the pressing member to close the opening, thereby fixing the embedded metal fitting to the formwork, and after fixing the embedded metal fitting to the formwork, pouring concrete.

[0008] In the method for pre-attaching embedded metal fittings with the above-mentioned features, the opening is preferably a circular hole, and the receiving member has at least a long side longer than the diameter of the circular hole and a short side shorter than the diameter of the circular hole. With such features, the receiving member can be inserted through the opening by tilting it, and when the receiving member is parallel to the surface of the formwork, it can be caught on the formwork.

[0009] In addition, in the formwork pre-attachment method for embedded metal fittings having the above-mentioned characteristics, it is preferable that the anchor part has a female threaded hole, the receiving member is fixed to the opening side of the female threaded hole, a bolt is threaded into the female threaded hole, and a force for clamping the plate surface between the receiving member and the pressure plate is generated by tightening a nut threaded onto the bolt. By having such characteristics, it is possible to easily insert the anchor part and the receiving member into the opening, and to clamp the formwork between the receiving member and the pressure plate.

[0010] In addition, in the formwork pre-installation method for embedded metal fittings having the above-mentioned characteristics, the length of the bolt is preferably longer than the depth of the female threaded hole, and the steps of inserting the anchor part and the receiving member and fixing the embedded metal fitting are preferably performed with the bolt fully tightened into the female threaded hole. This characteristic restricts rotation of the anchor part relative to the bolt. This makes the rotation angle of the bolt and the rotation angle of the anchor part equal, making it easy to determine the orientation of the receiving member when fixing the embedded metal fitting to the formwork.

[0011] Furthermore, in the method for pre-attaching embedded metal fittings with the above-mentioned characteristics, the openings can be reused as openings for fixing embedded metal fittings when the formwork is moved and reused. This characteristic eliminates the need to create openings and fill holes each time the formwork is used, thereby improving work efficiency.

[0012] In addition, the embedded metal fitting of the present invention, which is intended to achieve the above-mentioned object, is characterized by having an anchor portion having a female threaded hole formed at one end, a receiving member which is fixed to the opening of the female threaded hole and which can be inserted into an opening provided in the plate surface of the formwork and which is engaged with the plate surface after being inserted through the opening, a support member which supports the anchor portion, a pressing member which is arranged on the support member and can be moved along the extension direction of the anchor portion, a spacer which is arranged between the receiving member and the pressing member, and a biasing force generating means which is arranged on the support member and which applies a force to the pressing member in a direction that brings it closer to the receiving member.

[0013] Furthermore, in the embedded metal fitting having the above-mentioned characteristics, the support member can be a bolt, and the biasing force generating means can be a nut threaded onto the bolt. By having such characteristics, the support member and the biasing force generating means can be made of general-purpose products, thereby reducing manufacturing costs.

[0014] Furthermore, when the opening in the embedded metal fitting having the above-mentioned characteristics is rectangular, the receiving member may have a long side that is shorter than the long side or diagonal of the opening and longer than the short side of the opening, and a short side that is shorter than the short side of the opening. By having such characteristics, the receiving member can be inserted through the opening in the formwork and can also provide a catch on the edge of the opening.

[0015] Furthermore, when the opening in the embedded metal fitting having the above-mentioned characteristics is circular, it is preferable that the receiving member has a long side longer than the diameter of the circle and a short side shorter than the diameter of the circle. By having such a characteristic, the receiving member can be inserted through the opening in the formwork and can also provide a catch on the edge of the opening. [Effects of the Invention]

[0016] The pre-installation method for embedded metal fittings with the above-mentioned features allows for easy placement of embedded metal fittings from the front side of the formwork. It also allows for a high degree of freedom in placement of embedded metal fittings and eliminates the need for processing around the openings formed in the formwork.

[0017] Furthermore, any embedded metal fitting having the above-mentioned characteristics can be applied to the above-mentioned construction method. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is an exploded side view showing an example of an embedded metal fitting according to an embodiment. [Figure 2] FIG. 10 is a diagram showing an example in which the planar shape of the receiving member that constitutes the embedded metal fitting is rectangular. [Figure 3] This is a diagram showing an example of a receiving member that constitutes an embedded metal fitting, in which the planar view shape is a disk with a portion cut out along the chord. [Figure 4] This is a diagram showing an example in which the planar shape of the receiving member that constitutes the embedded metal fitting is a rectangular shape with chamfered corners. [Figure 5]This is a diagram showing the state in which a formwork is placed at the boundary with the concrete pouring area and an opening is formed in the plate surface. [Figure 6] 10 is a diagram showing how an embedded metal fitting is inserted into the concrete pouring area through an opening formed in the formwork. FIG. [Figure 7] This figure shows the state in which the embedded metal fittings are placed close to the edge of the opening when being inserted from the opening formed in the formwork to the concrete pouring area. [Figure 8] This is a diagram showing the state in which the anchor portion and receiving member of the embedded metal fitting are inserted into the concrete pouring area through an opening formed in the formwork. [Figure 9] This is a diagram showing the state in which the plate surface of the formwork is clamped by the receiving member and pressing member that make up the embedded metal fitting, temporarily fixing the embedded metal fitting. [Figure 10] FIG. 10 is a diagram showing the state after concrete has been poured and the bolts, nuts, spacers, and formwork have been removed. [Figure 11] FIG. 10 is a diagram showing the state in which embedded metal fittings are embedded continuously in a concrete wall surface. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following describes in detail the embodiments of the method for pre-attaching a metal formwork to a metal embedment of the present invention and the metal embedment of the present invention with reference to the drawings. Note that the embodiments shown below are some of the preferred forms for carrying out the present invention, and even if some of the configuration or method is changed, it can be considered as part of the present invention as long as the effect is achieved.

[0020] [Embedded hardware] First, the embedded metal used in the embedded metal formwork pre-attachment method according to the present invention will be described with reference to FIG. 1. In this embodiment, an anchor having a female threaded hole 12c will be described as an example of an embedded metal 10. The embedded metal 10 according to this embodiment is basically composed of an anchor portion 12, a receiving member 14, a holding member 18, and a spacer 16. The anchor portion 12 according to this embodiment has a cylindrical main body 12a and a fixing portion 12b at the tip of the embedded side, the fixing portion 12b having a larger diameter than the main body 12a. Furthermore, the main body 12a has a female threaded hole 12c with an opening at the end opposite the side where the fixing portion 12b is located, formed along the longitudinal direction.

[0021] The length of the anchor portion 12 is not limited, but is preferably equal to or less than the gap between the formwork 50 and the reinforcing bar 60 (see Figures 5-8). This is to allow for freedom in arranging the embedded metal fittings 10 and to prevent the anchor portion 12 from coming into contact with the reinforcing bar 60 when inserting the embedded metal fittings 10 through the openings 52 of the formwork 50. The diameter (projected surface in a plan view) of the anchor portion 12 may be large enough to pass through the openings 52 provided in the formwork 50, the details of which will be described later. The anchor portion 12 may be made of a material (e.g., a metal material) having a predetermined strength or greater, such as steel.

[0022] The receiving member 14 is a member disposed at the end of the anchor portion 12 on the side where the female screw hole 12c of the main body 12a is formed. The receiving member 14 is desirably fixed to the anchor portion 12 and is not limited to being formed separately, but may be formed integrally. The receiving member 14 may have any shape in plan view as long as it has at least long and short sides. For example, the receiving member 14 may be a rectangular plate as shown in FIG. 2, a disk-shaped plate with a circular arc cut out along a chord as shown in FIG. 3, a rectangular plate with chamfered corners (see FIG. 4), a rod-shaped member, or the like. The receiving member 14 is provided with a through-hole 14a for inserting a bolt 22, the details of which will be described later.

[0023] The ratio of the long side to the short side of the receiving member 14 is not uniquely determined, and is preferably determined in consideration of the opening 52 provided in the plate surface of the formwork 50, the details of which will be described later. Specifically, it is sufficient that at least a part of the long side of the receiving member 14 catches when it is parallel to the opening 52, and that the receiving member 14 can pass through the opening 52 when it is rotated or tilted.

[0024] For this reason, it is sufficient that the long sides of the receiving member 14 are at least longer than the diameter of the opening 52 (if the opening 52 is circular) or the short sides of the opening 52, and the short sides of the receiving member 14 are shorter than the diameter or short sides of the opening 52. Here, like the anchor part 12, the receiving member 14 is desirably made of a metal member such as steel, but there are no restrictions on the material as long as it does not deform due to the load or impact when the concrete 70, which will be described in detail later, is poured.

[0025] The holding member 18 should have a side longer than the diameter or shorter side of the opening 52, and should be configured to hook onto the opening 52 at least when placed parallel to the plate surface of the formwork 50. A holding member 18 configured in this manner allows the receiving member 14 and the holding member 18 to sandwich the plate surface of the formwork 50 through the opening 52. Like the receiving member 14 and anchor portion 12, the holding member 18 is preferably made of a metal material such as steel, but like the receiving member 14, the material is not limited as long as it does not deform when the concrete 70 is poured. Like the receiving member 14, the holding member 18 also has a through hole 18a for inserting the bolt 22.

[0026] The spacer 16 is an element disposed between the receiving member 14 and the pressing member 18, and serves to close the opening 52 formed in the formwork 50. For this reason, it is desirable that the spacer 16 have a shape similar to that of the opening 52 with a minus tolerance (for example, about minus 1 mm). If the area of the opening 52 that is covered by the pressing member 18 is large, the spacer 16 may be made of a soft material (for example, rubber), and in this case, the spacer 16 may be formed larger than the opening 52 as long as it can be fitted into the opening 52 by shrinking it.

[0027] Like the receiving member 14 and the holding member 18, the spacer 16 is also provided with a through hole for inserting the bolt 22. The thickness of the spacer 16 is preferably equal to or less than the thickness of the plate surface of the formwork 50, and is strong enough to prevent leakage of the concrete 70 being poured.

[0028] As described above, the embedded metal fitting 10 according to the embodiment is basically composed of the anchor portion 12, the receiving member 14, the pressing member 18, and the spacer 16. However, during use, i.e., pre-installation, a bolt 22 (supporting member) threaded with a nut 20 serving as a biasing force generating means is threaded into the female threaded hole 12c of the anchor portion 12, and the nut 20 threaded onto the bolt 22 moves the pressing member 18 and the spacer 16 toward the receiving member 14, thereby clamping the surface of the formwork 50. Therefore, the bolt 22 and the nut 20 can also be defined as part of the embedded metal fitting 10 according to the embodiment. Note that the support member does not have to be the bolt 22, and the biasing force generating means does not have to be the nut 20, as long as it is capable of supporting the anchor portion 12 and moving the pressing member 18 and the spacer 16 toward the receiving member 14.

[0029] Furthermore, in the above description, the anchor portion 12 is described as having a cylindrical main body 12a. However, the anchor portion 12 may have a polygonal cylindrical shape, such as a rectangular or triangular prism, and the cross-sectional shape is not limited thereto. Furthermore, since the anchor portion 12b is described as having a cylindrical main body 12a, the anchor portion 12b is described as having a larger diameter than the main body 12a. However, the planar shape of the anchor portion 12b is not limited thereto as long as the projected area of the anchor portion 12b from the longitudinal end of the main body 12a is larger than the projected area of the main body 12a. Furthermore, although the anchor portion 12b is described as being located at the tip of the embedded side of the main body 12a, this is not a limitation, and two or more anchor portions may be provided. Furthermore, in the example shown in FIG. 1, the anchor portion 12b is depicted as a convex flange relative to the main body 12a. However, as long as it can effectively prevent the anchor portion 12b from slipping out of the concrete 70, the anchor portion 12b may be, for example, a concave constriction.

[0030] [Formwork pre-attachment method] Next, a formwork pre-attaching method using the embedded metal fittings as described above will be described with reference to FIGS.

[0031] First, a form 50 is placed to separate an area where reinforcing bars 60 such as main reinforcement and reinforcing bars are arranged (a concrete pouring area) from an area where concrete 70 will not be poured, and an opening 52 is provided in a predetermined position of this form 50 for pre-attaching an embedded metal fitting 10 (see FIG. 5). The opening 52 may be provided in the plate surface of the form 50, one side of which is the side where concrete will be poured and the other side of which is the side where concrete will not be poured. The shape of the opening 52 in a plan view may be, for example, circular, and its size may be such that its diameter is smaller than the long side of the receiving member 14 described above and larger than the short side.

[0032] Next, as shown in Figure 6, the anchor portion 12 and receiving member 14 of the embedded metal fitting 10 are inserted into the opening 52 from the other side of the formwork 50. Here, the anchor portion 12 is inserted into the opening 52 after the bolt 22 with the nut 20 threaded thereon is threaded into the female threaded hole 12c. Since it is possible to grasp the bolt 22 protruding from the anchor portion 12, the insertion operation of the anchor portion 12 and the receiving member 14 becomes easy. When threading the bolt 22 into the female threaded hole 12c, a spacer 16 and a pressing member 18 are placed between the nut 20 and the receiving member 14.

[0033] Here, the insertion of the receiving member 14 into the opening 52 is preferably performed by tilting the anchor portion 12 and the receiving member 14 with respect to the opening 52, as shown in Fig. 6. Furthermore, as shown in Fig. 7, by bringing the side of the bolt 22 or anchor portion 12, at which the end of the long side of the receiving member 14 opposite the end to be inserted, close to the edge of the opening 52, the insertion of the receiving member 14 can be made easier.

[0034] After inserting the anchor portion 12 and the receiving member 14 through the opening 52, the embedded metal fitting 10 is adjusted so that the receiving member 14 is parallel to the surface of the formwork 50 and the anchor portion 12 is perpendicular to the surface of the formwork 50 (see Figure 8). By arranging it in this way, the receiving member 14 will be caught in the opening 52.

[0035] 9, the plate surface of the formwork 50 is sandwiched between the receiving member 14 and the pressing member 18. The formwork 50 can be sandwiched by rotating the nut 20, which is threaded onto the male thread of the bolt 22, toward the receiving member 14 so that the pressing member 18 is pressed against the plate surface of the formwork 50.

[0036] Here, a spacer 16 is placed in advance between the receiving member 14 and the pressing member 18. Therefore, when the pressing member 18 is pressed against the plate surface of the formwork 50 by the nut 20, the spacer 16 fits into the opening 52, and the opening 52 of the formwork 50 is closed.

[0037] After the embedded metal fittings 10 have been placed and fixed in the formwork 50 in this manner, concrete 70 is poured into the concrete pouring area. The embedded metal fittings 10 are prevented from coming out of the formwork 50 by the receiving members 14, and the openings 52 are sealed by the spacers 16. Therefore, the load exerted when pouring the concrete 70 will not cause the embedded metal fittings 10 to fall out of the openings 52, nor will large amounts of concrete 70 (including cement milk, etc.) leak out of the openings 52.

[0038] After the poured concrete 70 has hardened, the bolts 22 are unscrewed to release the clamping member 18 and spacer 16, and the formwork 50 is removed, completing the installation of the embedded metal fittings 10 on the concrete wall surface as shown in Figure 10.

[0039] [effect] The above-described method of pre-attaching embedded metal fittings to the formwork is easy to work with, as the embedded metal fittings 10 can be temporarily fixed simply by clamping the surface of the formwork 50 between the receiving member 14 and the holding member 18. In addition, the action of the receiving member 14 prevents the embedded metal fittings 10 from falling when the concrete is poured.

[0040] Furthermore, the embedded metal fittings 10 can be attached (temporarily fixed) only from the other side of the formwork 50 (the area where the concrete 70 will not be poured). Therefore, even if the area where the concrete will be poured is narrow, the embedded metal fittings 10 can be easily attached to the formwork in advance.

[0041] Furthermore, the opening 52 formed in the formwork 50 can be made smaller than in the past, and there is no need to install auxiliary members or the like around the opening 50 to fix the embedded metal fittings 10, resulting in high work efficiency.

[0042] [Application example] In the above embodiment, the opening 52 for placing the embedded metal fitting 10 is described as being formed after the formwork 50 is placed. However, the opening 52 may be formed in the formwork 50 before the formwork 50 is placed. This is because by providing the opening 52 in the formwork 50 in advance, it is possible to reduce the number of work processes on site.

[0043] Furthermore, when forming a concrete covering layer by using a common or several types of formwork 50 in succession, such as in the centering method in tunnel construction, it is advisable to use the openings 52 first made in the formwork 50 to pre-install the embedded metal fittings 10 after the formwork has been moved. This is because it saves the effort of sequentially making openings 52 in the formwork 50 and closing the unused openings.

[0044] Furthermore, when threading the bolt 22 into the anchor portion 12, it is advisable to temporarily fix the bolt 22 to the formwork 50 with the bolt 22 threaded all the way into the female threaded hole 12c. Rotation of the anchor portion 12 relative to the bolt 22 is restricted, so that rotating the bolt 22 rotates the anchor portion 12 by the same rotation angle. This makes it easy to determine the arrangement direction of the receiving member 14 attached to the anchor portion 12, and when multiple embedded metal fittings 10 are arranged consecutively, it is easy to unify the direction of the long sides of the receiving member 14, as shown in Figure 11. [Explanation of symbols]

[0045] 10....Embedded metal fitting, 12....Anchor part, 12a....Main body, 12b....Fixing part, 12c....Female screw hole, 14....Receiving member, 16....Spacer, 18....Pressing member, 20....Nut, 22....Bolt, 50....Formwork, 52....Opening, 60....Reinforcing bar, 70....Concrete.

Claims

1. A circular hole is provided at a predetermined position on the surface of a plate constituting a formwork having one side on which concrete is poured and the other side on which concrete is not poured, Inserting an anchor portion of an embedded metal fitting and a receiving member that abuts against the anchor portion in an embedded state from the other side surface side to the one side surface side through the opening; The plate surface is sandwiched between the receiving member arranged on one side surface side and the pressing member arranged on the other side surface side, and a spacer that closes the opening is arranged between the receiving member and the pressing member to fix the embedded metal fitting to the formwork, A method for pre-attaching embedded metal to a formwork, in which the embedded metal is fixed to the formwork and then concrete is poured, characterized in that the receiving member is made of a plate or rod-shaped member, and the length of at least the long side is longer than the diameter of the round hole and the length of the short side is shorter than the diameter of the round hole.

2. A female screw hole is formed in the anchor portion, and the receiving member is fixed to an opening side of the female screw hole, A method for pre-attaching embedded metal fittings to a formwork as described in claim 1, characterized in that a bolt is screwed into the female threaded hole, and by tightening the nut screwed onto the bolt, a force is generated to clamp the plate surface between the receiving member and the pressing member.

3. The length of the bolt is longer than the depth of the female screw hole, The method for pre-attaching embedded metal fittings to a formwork as described in claim 2, characterized in that the process of inserting the anchor portion and the receiving member and the process of fixing the embedded metal fittings are carried out with the bolt tightened all the way into the female threaded hole.

4. A method for pre-attaching embedded metal fittings to a formwork according to any one of claims 1 to 3, characterized in that the opening is reused as an opening for fixing embedded metal fittings when the formwork is moved and reused.

5. An anchor portion having a female screw hole formed at one end thereof; a receiving member that is made of a plate material or a rod-shaped member having long sides and short sides, that is fixed to the opening of the female screw hole, that can be inserted into an opening provided in the plate surface of the formwork, and that is engaged with the plate surface after being inserted through the opening; a support member that supports the anchor portion; a pressing member disposed on the support member and movable along the extending direction of the anchor portion; a spacer disposed between the receiving member and the pressing member; and a biasing force generating means that is disposed on the support member and applies a force to the pressing member in a direction that brings it closer to the receiving member.

6. the support member is a bolt; 6. The embedded metal fitting according to claim 5, wherein the biasing force generating means is a nut threaded onto the bolt.

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