Grout injection formwork and grout injection method

Abstract

To provide formwork for grout injection and a grout injection method that can efficiently and securely fill grout to all filled space with which a PCa member is provided.SOLUTION: A formwork 10 for grout injection is applied when reinforcing-bars 65 are inserted into sheath pipes 63 with which a PCa member 60 is provided, the reinforcing-bars 65 are mounted while inserting at an end surface 61 of the PCa member 60, and grout is injected to the sheath pipes 63. The formwork for grout injection has a formwork face material 11 comprising insertion holes 15 that are built at the position corresponding to the sheath pipes 63 and where the reinforcing-bars 65 are inserted, and an injection hole 14 where the grout is injected, an endless-like seal material 21 that is attached to a back face 13 opposed to the sheath pipes 63 on the formwork face material 11 and is abutted on the first end surface 61 by surrounding first openings where the insertion holes 15 face the back face 13 and a second opening where the injection hole 14 faces the back face 13, and temporary fixing materials 19 that are temporarily fixed to the PCa member 60.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a form for grout injection and a grout injection method. [Background technology]

[0002] For example, when constructing a column-beam joint in a reinforced concrete (RC) structure by pouring concrete on-site, the construction period can be lengthy, a problem that becomes even more pronounced in the case of high-rise buildings. Therefore, a construction method may be adopted in which the upper and lower columns, the joints connecting the columns, and the beams on either side of the joints are all made of precast concrete (hereinafter referred to as "PCa"), the PCa columns, PCa joints, and PCa beams (all of which are included in PCa components) are transported to the site, and after the PCa columns and PCa joints are assembled, PCa beams are temporarily installed on either side of the PCa joint. The rebar that protrudes laterally from the end face of one of the PCa beams is inserted into the sheath pipe provided in the PCa joint, protruding to the other side of the PCa joint, and the rebar is fitted into a mechanical joint inside the other PCa beam, thereby connecting the PCa joint to the left and right PCa beams.

[0003] This connection method then requires the injection of grout into the sheath pipe of the PCa joint and into the mechanical joints inside the PCa beams that connect the rebars to each other, thereby connecting the rebars to the sheath pipes and mechanical joints. Therefore, a method is used in which grout injection holes are provided in the mechanical joints, and the grout injected through the injection holes fills the interconnected spaces. Specifically, the grout filled inside the mechanical joints flows into the vertical joint space at the interface between the PCa beam equipped with the mechanical joint and the PCa joint, then flows through the sheath pipe of the PCa joint, and finally flows into the vertical joint space between the PCa joint and the other PCa beam. The other PCa beam is provided with a discharge hole connected to the vertical joint space. By confirming that the grout flowing into the vertical joint space is discharged from the discharge hole, it is possible to determine whether each space has been filled with grout.

[0004] However, even if it is possible to confirm that the grout injected from the injection hole passes through various filled spaces and is discharged from a discharge hole located away from the injection hole, it is not necessarily guaranteed that all of the mutually communicating filled spaces are densely filled with grout. It is quite possible that some filled spaces will not be filled with grout due to some influence, or that the grout will flow to the discharge hole and be discharged in a state where it is not filled sufficiently.

[0005] In view of the above, when connecting one PCa member equipped with a sheath tube to another PCa member having reinforcing bars protruding from its end face, a method of connecting the grout injection jig and the PCa member is desired that can efficiently and reliably fill all of the spaces to be filled with grout.

[0006] Patent Document 1 proposes a precast beam member and a beam construction method therefor. The precast beam member has multiple shear reinforcement bars embedded at intervals in precast concrete, and multiple parallel sheath pipes embedded in each precast concrete for inserting the lower beam main reinforcement bars between the lower ends of two precast concrete pieces. Splice reinforcement is arranged in the center of the sheath pipes, forming a lap splice formation area. The beam construction method for precast beam members involves inserting the lower beam main reinforcement bars through the sheath pipes of the beam members and installing them sequentially between the tops of the columns. The lower beam main reinforcement bars are then moved and adjusted to pass them between the end faces of the precast beam members above the column tops to form reinforcement. The front and rear ends of each lower beam main reinforcement are then connected within the lap splice formation area. Concrete is then poured between the end faces of the precast beam members, and grout is filled into each sheath pipe to construct the precast beam member. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 5-247999 Summary of the Invention [Problem to be solved by the invention]

[0008] The beam construction method for precast beam members described in Patent Document 1 merely describes that the beam is constructed by filling grout material into the sheath tube, but does not disclose any means or method for reliably filling grout into all of the spaces to be filled with grout.

[0009] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a grout injection formwork and a grout injection method that can efficiently and reliably fill all of the filled spaces in a PCa member with grout. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of the grout injection formwork according to the present invention is as follows: A grout injection formwork is used when a reinforcing bar is inserted into a sheath pipe provided in a precast concrete PCa member, and the reinforcing bar is inserted and installed at the end face of the PCa member, and grout is injected into the sheath pipe. A formwork face material having an insertion hole opened at a position corresponding to the sheath pipe and through which the reinforcing bar is inserted, and an injection hole through which grout is injected; an endless sealing material attached to a back surface of the formwork face material facing the sheath tube, surrounding a first opening where the insertion hole faces the back surface and a second opening where the injection hole faces the back surface, and abutting against a side surface of the PCa member; It is characterized by having a temporary fixing material that is temporarily fixed to the PCa member.

[0011] According to this aspect, by including a formwork face material having an insertion hole through which a reinforcing bar is inserted together with a sheath tube and an injection hole through which grout is injected, an endless sealing material surrounding the first opening of the insertion hole and the second opening of the injection hole on the back surface of the formwork face material, and a temporary fixing material temporarily fixed to the PCa member, it is possible to reliably fill the sheath tube (filled space) of the PCa member through which the reinforcing bar is inserted with grout. That is, the grout injected into the back surface of the formwork face material through the injection hole accumulates inside the sealing material that seals the gap between the back surface and the side surface of the PCa member, and then the accumulated grout fills the inside of the sheath tube through which the reinforcing bar is inserted, thereby reliably filling the inside of the sheath tube with grout.

[0012] Another aspect of the grout injection form according to the present invention is The catheter is characterized by having a plurality of the insertion holes corresponding to the plurality of sheath tubes, respectively.

[0013] According to this embodiment, even when the PCa member has multiple sheath tubes, the grout injected onto the back surface of the formwork face material accumulates inside the sealing material that seals the space between the back surface and the side surface of the PCa member, and the accumulated grout is then filled into the insides of the multiple sheath tubes, thereby ensuring that the grout is filled into the insides of the multiple sheath tubes.

[0014] In another aspect of the grout injection form according to the present invention, An insert is embedded in the PCa member, and an end of the insert faces a side surface of the PCa member, The temporary fixing material is temporarily fixed to the insert.

[0015] According to this embodiment, the temporary fixing material is temporarily fixed to the insert embedded in the PCa member, so that the formwork for grout injection can be easily and reliably temporarily fixed to the PCa member when injecting grout, and the formwork for grout injection can be quickly removed from the PCa member after the grout is injected.

[0016] Further, one aspect of the grout injection method according to the present invention is to A grout injection method for injecting grout into a sheath pipe provided in a PCa member, A formwork face material that is opened at a position corresponding to the sheath pipe and has an insertion hole through which a reinforcing bar is inserted; an injection hole into which grout is injected; an endless sealing material attached to a back surface of the formwork face material facing the sheath tube, surrounding a first opening where the insertion hole faces the back surface and a second opening where the injection hole faces the back surface, and abutting against a side surface of the PCa member; A process A includes preparing a grout injection formwork having a temporary fixing material that is temporarily fixed to the PCa member; a step B in which the PCa member has a first end face on which the grout injection formwork is installed and a second end face opposite to the first end face, the sheath tube has a first end face opening facing the first end face and a second end face opening facing the second end face, and the grout injection formwork is installed on the first end face while aligning the insertion hole with the first end face opening; A step C of inserting the reinforcing bar into the sheath tube through the insertion hole and confirming that the grout injected into the sheath tube is discharged by aligning a discharge confirmation jig with the second end surface opening and installing it around the reinforcing bar; and a D step of injecting grout into the space between the back surface and the first end face and into the interior of the sealing material through the injection hole, allowing the injected grout to flow inside the sheath tube, and confirming that the grout has been discharged using the discharge confirmation jig.

[0017] According to this aspect, by using the grout injection formwork of the present invention, grout can be reliably injected into the sheath pipe of the PCa member through which the reinforcing bars are inserted.

[0018] In another aspect of the grout injection method according to the present invention, In the step A, the grout injection formwork having a plurality of insertion holes corresponding to a plurality of the sheath tubes is prepared, In the step B, a plurality of grout injection forms are installed while being aligned with the first end surface openings, In the step C, a plurality of the reinforcing bars are inserted into a plurality of sets of the insertion holes and the sheath tubes, and a plurality of the discharge confirmation jigs are installed while being aligned with a plurality of the second end surface openings, The step D is characterized by injecting grout into the plurality of sheath tubes.

[0019] According to this aspect, even if a PCa member has multiple sheath pipes, by applying the grout injection formwork of the present invention, grout can be reliably filled into all sheath pipes through which reinforcing bars have been inserted. [Effects of the Invention]

[0020] As can be understood from the above explanation, the grout injection formwork and grout injection method of the present invention enable grout to be efficiently and reliably filled into all of the spaces to be filled that are provided in the PCa member. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of an example of a formwork for grout injection according to an embodiment. [Figure 2] FIG. 2 is a process diagram of an example of a grout injection method according to an embodiment. [Figure 3] 2, is a process diagram of an example of a grout injection method according to an embodiment. [Figure 4] 4 is a process diagram of an example of a grout injection method according to an embodiment, following FIG. 3. [Figure 5] 5 is a process diagram of an example of a grout injection method according to an embodiment, following FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an example of a grout injection formwork and a grout injection method according to an embodiment will be described with reference to the accompanying drawings. Note that in this specification and the drawings, substantially identical components are designated by the same reference numerals, and redundant description may be omitted.

[0023] [Grout injection formwork according to the embodiment] First, an example of a formwork for grout injection according to an embodiment will be described with reference to Fig. 1. Here, Fig. 1 is a perspective view of an example of a formwork for grout injection according to an embodiment.

[0024] The grout injection formwork 10 is a formwork that is used when reinforcing bars are inserted into the sheath pipes provided in the PCa member, and the formwork is installed at the end face of the PCa member while the reinforcing bars are inserted, and grout is injected into the sheath pipes.

[0025] The formwork 10 for grout injection has a formwork face material 11 that is rectangular in plan view, an endless sealing material 21 attached to the back surface 13 of the formwork face material 11 that faces the side surface (sheath tube) of the PCa member, and temporary fixing materials 19 (bolts) that are inserted into temporary fixing holes 18 opened at each corner of the rectangle of the formwork face material 11 and temporarily fixed to the PCa member.

[0026] The formwork face material 11 is formed from a wood material such as plywood or solid wood, a hard resin material, a steel plate, etc. The formwork face material 11 is provided with a plurality of insertion holes 15 (12 in the illustrated example) opened at positions corresponding to the sheath pipes of the PCa members and through which reinforcing bars are inserted, and injection holes 14 through which grout is injected. The injection holes 14 are formed by injection pipes protruding outward from the front surface 12 of the formwork face material 11, and grout injected from the injection port of the injection pipe is allowed to pass through the injection holes 14 and fill the back surface 13.

[0027] Endless sealing material 21 surrounds a first opening on rear surface 13 of formwork face material 11 where multiple insertion holes 15 face rear surface 13 and a second opening where injection hole 14 faces rear surface 13 .

[0028] The sealing material 21 is formed of a backing material such as a hard sponge, and its thickness t1 is set to about 20 mm.

[0029] By using such a hard and deformable sealing material 21, when the grout injection formwork 10 is tightened with the bolts 19, the sealing material 21 does not get crushed too much, and the initial thickness is maintained to ensure a reliable seal between the side surface of the PCa member. This makes it possible to fill the space formed by the height of the sealing material 21 with grout, and then smoothly fill the interiors of the multiple sheath pipes with grout.

[0030] For example, if the thickness of the sealing material 21 is about 10 mm, the grout cannot flow sufficiently from the inside of the sealing material to the inside of each sheath tube, which may result in poor workability. On the other hand, if the thickness of the sealing material 21 exceeds 20 mm, the amount of grout used may be more than necessary, which may lead to material loss, such as some grout being discarded.

[0031] When grout is injected into the multiple sheath tubes and the grout injection formwork 10 is removed from the side of the PCa member, the hardened grout that has accumulated inside the sealing material 21 can become a vertical joint between the two PCa members that are to be connected to each other. Setting the thickness of the sealing material 21 to about 20 mm makes this a suitable thickness from the viewpoint of enabling the thickness of the vertical joint to be formed to a preferable thickness of about 20 mm.

[0032] By using the grout injection formwork 10, grout injected into the back surface 13 of the formwork face material 11 through the injection holes 14 accumulates inside the sealing material 21 that seals between the back surface 13 and the side surface of the PCa member, and the accumulated grout then fills the inside of the sheath tube of the PCa member through which the rebar is inserted, thereby ensuring that the inside of the sheath tube is filled with grout. In particular, when the PCa member has multiple sheath tubes, it becomes possible to reliably and efficiently fill all of the sheath tubes with grout.

[0033] [Grout injection method according to the embodiment] Next, an example of a grout injection method according to an embodiment will be described with reference to Fig. 1 and Fig. 2 to Fig. 5. Here, Fig. 2 to Fig. 5 are process diagrams of an example of a grout injection method according to an embodiment, in order.

[0034] In the following explanation, a PCa joint, which is a first PCa member 60 made of precast concrete, is equipped with multiple sheath pipes 63, and the method for connecting this first PCa member 60 to two PCa beams, which are second PCa members 70 made of precast concrete on the left and right sides of it, will be explained.

[0035] At the construction site, a PCa column 68 is erected, and a PCa joint 60 is installed at the top end of the PCa column 68. Although not shown, multiple mechanical joints are embedded, for example, below the PCa joint 60, and the main column reinforcement bars protruding upward from the top end surface of the PCa column 68 are fitted into the mechanical joints below the PCa joint. A horizontal joint (not shown) is formed between the PCa column 68 and the PCa joint 60 by injecting grout, and this grout penetrates into the mechanical joints, connecting the main column reinforcement bars to the mechanical joint. Although not shown, the PCa joint 60 has multiple joint reinforcement bars protruding upward from its top end surface, and the joint reinforcement bars are fitted into mechanical joints below the PCa column of the upper floor (not shown).

[0036] In the grout injection method, first, a grout injection formwork 10 shown in FIG. 1 is prepared (step A).

[0037] Next, as shown in Fig. 2, a grout injection formwork 10 is installed in the PCa joint 60. In the illustrated example, the left end face of the PCa joint 60 is the first end face 61, and the right end face is the second end face 62. A plurality of sheath tubes 63 (12 in the illustrated example) extend horizontally between the first end face 61 and the second end face 62, and a first end face opening 63a and a second end face opening 63b are provided at positions facing each end face of the sheath tubes 63, respectively.

[0038] The first end surface 61 faces the first end surface openings 63a of each of the 12 sheath tubes 63, and prior to the installation of the grout injection formwork 10, spacers 50 are installed in the left and right end regions of each sheath tube 63 to align the first reinforcing bar 65, which will be inserted in a subsequent process, with the center of the cross section of the sheath tube 63.

[0039] After the spacer 50 is installed in the sheath pipe 63, the grout injection form 10 is attached to the first end face 61 of the PCa connection 60 while aligning the corresponding insertion holes 15 with the first end face openings 63a.

[0040] Four inserts 64 are embedded in the first end face 61 of the PCa joint 60, with their end openings facing the first end face 61. After the grout injection formwork 10 is aligned with the first end face 61, bolts 19 are tightened into the inserts 64 through the temporary fixing holes 18, whereby the sealing material 21 is pressed against the first end face 61 and tightly adheres to it, and the grout injection formwork 10 is installed against the first end face 61 (this is process B).

[0041] Next, the first reinforcing bar 65 is inserted into each sheath tube 63, and is temporarily installed in each sheath tube 63 in a state where the first reinforcing bar 65 protrudes from both the first end surface opening 63a and the second end surface opening 63b.

[0042] A discharge confirmation jig 30 for confirming that the grout injected into the sheath pipe 63 is being discharged is aligned with the plurality of second end face openings 63b facing the second end face 62 of the PCa connection 60, installed around the corresponding first reinforcing bars 65, and fixed with a lock nut 40. The discharge confirmation jig 30 is provided with a discharge port 31 that communicates with the second end face openings 63b. As the discharge confirmation jig 30, for example, a backer material with a slit that becomes the discharge port 31 is used (this is process C).

[0043] Next, as shown in Figure 3, grout is injected in the Y1 direction into the space between the back surface 13 of the formwork face material 11 and the first end face 61 of the PCa joint 60, and into the inside of the sealing material 21, through the injection hole 14 of the grout injection formwork 10.

[0044] The injected grout flows in the Y2 direction into the inside of the sealing material 21 that seals between the back surface 13 and the first end face 61 and accumulates therein, and then the accumulated grout is filled in the Y3 direction into the inside of each sheath tube 63 through which the first reinforcing bar 65 is inserted.

[0045] The grout that has flowed inside the sheath tube 63 in the Y3 direction is discharged (discharged) from the discharge ports 31 of the discharge checking jigs 30 to the outside in the Y4 direction via the second end surface openings 63b.

[0046] By checking the discharge of this grout, the worker can determine that the inside of the sheath pipe 63 is densely filled with grout (this is step D).

[0047] After it has been confirmed that each sheath pipe 63 has been filled with grout, the grout injection formwork 10 and each discharge confirmation jig 30 are removed as shown in Fig. 4. As shown in Fig. 4, the first reinforcing bar 65 is aligned with the center of the cross section of each sheath pipe 63, and the space between the first reinforcing bar 65 and the inner surface of the sheath pipe 63 is densely filled with grout G.

[0048] Furthermore, a vertical joint 91 is formed on the side of the first end face 61 of the PCa connection 60, where the grout that has accumulated inside the sealing material 21 has hardened.

[0049] Next, the left and right ends of the first reinforcing bar 65 and the ends of the second reinforcing bars 75 protruding from the ends of the PCa beams 70 on the left and right are screwed into mechanical joints 72 such as couplers, thereby connecting the first reinforcing bar 65 and the second reinforcing bar 75 via the mechanical joints 72, and grout or epoxy resin, etc. is also injected into the inside of the mechanical joints 72.

[0050] Next, as shown in Figure 5, concrete is poured into the space between the PCa joint 60 and the left and right PCa beams 70 so as to bury a portion of the first reinforcing bar 65, the mechanical joint 72, and a portion of the second reinforcing bar 75, and by constructing, for example, a concrete connector 80 having the same cross-sectional shape and dimensions as the PCa beam 70, the PCa joint 60 and the PCa beam 70 are connected via the concrete connector 80, and a column-beam joint 100 is constructed.

[0051] When constructing this beam-column joint 100, a vertical joint space is formed on the side of the second end face 62 of the PCa joint 60, and finally grout is injected to construct the vertical joint 92.

[0052] According to the illustrated grout injection method, by using a grout injection formwork 10, grout can be reliably and efficiently injected into multiple sheath pipes 63 of a PCa joint 60 through which a first reinforcing bar 65 is inserted.

[0053] Furthermore, by temporarily fixing the grout injection formwork 10 by screwing a bolt 19 into the insert 64 embedded in the PCa joint 60, the grout injection formwork 10 can be easily and reliably temporarily fixed to the first end face 61 of the PCa joint 60 when injecting grout, and after the grout is injected, the grout injection formwork 10 can be quickly removed from the first end face 61, further improving the workability of grout injection.

[0054] The present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0055] 10: Grout injection formwork 11: Formwork surface material 12:Front 13: Back 14: Injection hole (second opening) 15: Insertion hole (first opening) 18: Temporary fixing hole 19: Temporary fixing material (bolt) 21: Sealing material 30: Ejection confirmation jig 31:Discharge port 40: Lock nut 50: Spacer 60: First PCa member (PCa joint, PCa member) 61: 1st end face (end face) 62: Second end face (end face) 63: Sheath tube 63a: First end opening (end opening) 63b: 2nd end opening (end opening) 64: Insert 65: First rebar (rebar) 68: PCa pillar 70: Second PCa member (PCa beam, PCa member) 72: Mechanical coupling 75: Second rebar (rebar) 80: Concrete connector 91,92:Vertical joint 100: Column beam joint G: Grout

Claims

1. A grout injection formwork is used when a reinforcing bar is inserted into a sheath pipe provided in a precast concrete PCa member, and the reinforcing bar is inserted and installed at the end face of the PCa member, and grout is injected into the sheath pipe. A formwork face material having an insertion hole opened at a position corresponding to the sheath pipe and through which the reinforcing bar is inserted, and an injection hole through which grout is injected; an endless sealing material attached to a back surface of the formwork face material facing the sheath tube, surrounding a first opening where the insertion hole faces the back surface and a second opening where the injection hole faces the back surface, and abutting against a side surface of the PCa member; A formwork for grout injection, characterized in that it has a temporary fixing material that is temporarily fixed to the PCa member.

2. 2. The grout injection form according to claim 1, comprising a plurality of the insertion holes corresponding to the plurality of sheath pipes, respectively.

3. An insert is embedded in the PCa member, and an end of the insert faces a side surface of the PCa member, 3. A form for grout injection according to claim 1 or 2, characterized in that the temporary fixing material is temporarily fixed to the insert.

4. A grout injection method for injecting grout into a sheath pipe provided in a PCa member, A formwork face material that is opened at a position corresponding to the sheath pipe and has an insertion hole through which a reinforcing bar is inserted; an injection hole into which grout is injected; an endless sealing material attached to a back surface of the formwork face material facing the sheath tube, surrounding a first opening where the insertion hole faces the back surface and a second opening where the injection hole faces the back surface, and abutting against a side surface of the PCa member; A process A includes preparing a grout injection formwork having a temporary fixing material that is temporarily fixed to the PCa member; a step B in which the PCa member has a first end face on which the grout injection formwork is installed and a second end face opposite to the first end face, the sheath tube has a first end face opening facing the first end face and a second end face opening facing the second end face, and the grout injection formwork is installed on the first end face while aligning the insertion hole with the first end face opening; A process C includes inserting the reinforcing bar into the sheath tube through the insertion hole, and aligning a discharge confirmation jig with the second end surface opening and installing it around the reinforcing bar to confirm that the grout injected into the sheath tube is discharged. and step D of injecting grout into the space between the back surface and the first end face and into the interior of the sealing material through the injection hole, allowing the injected grout to flow inside the sheath tube, and confirming that the grout has been discharged using the discharge confirmation jig.

5. In the step A, the grout injection formwork having a plurality of insertion holes corresponding to a plurality of the sheath tubes is prepared, In the step B, a plurality of grout injection forms are installed while being aligned with the first end surface openings, In the step C, a plurality of the reinforcing bars are inserted into a plurality of sets of the insertion holes and the sheath tubes, and a plurality of the discharge confirmation jigs are installed while being aligned with a plurality of the second end surface openings, The grout injection method according to claim 4, wherein in the step D, grout is injected into a plurality of the sheath tubes.

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