JP2016172365A - Member for forming grout injection/discharge hole and method for forming grout injection/discharge hole using the member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member for forming a grout injection/discharge hole and a method for forming the grout injection/discharge hole using the member, simple in handling and excellent in workability when forming the grout injection/discharge hole communicating in a sleeve joint of a precast concrete structure.SOLUTION: There is provided a method for forming a grout injection/discharge hole communicating in a sleeve joint of a precast concrete structure including forming the grout injection/discharge hole by screwing a tip of an elastic body tube into a connection port of the sleeve joint, then inserting a core material with outer diameter same as inner diameter of the elastic body tube or smaller than inner diameter of the elastic body tube and sandwiching the tip of the elastic body tube with the core material and the connection port of the sleeve joint to fix the tip and pulling the elastic body tube together with the core material after concrete solidification to extend the elastic body tube and pulling out while peeling from the concrete.SELECTED DRAWING: Figure 1

Description

  The present invention provides a grout injection hole forming member for forming a grout injection (discharge) hole in a sleeve joint of a precast concrete structure used when a large structure made of reinforced concrete is constructed, and a grout injection using the member. The present invention relates to a method for forming an exhaust hole.

  Generally, when a reinforced concrete structure is constructed, a sleeve joint is used to connect long main reinforcing bars. The sleeve joint is provided with an injection port for injecting a grout such as a high fluidity non-shrink mortar and a discharge port for discharging the grout through a rebar inserted in both ends of a cylindrical body. The main rebar is connected by solidification of the injected grout.

  For example, a precast reinforced concrete structure used for walls, columns, etc. has a plurality of reinforcing bars connected to the upper ends of a plurality of sleeve joints, and the lower ends of the sleeve joints are configured to open to the bottom surface of the concrete structure. ing. The sleeve joint has a grout inlet formed at the lower end, a grout outlet formed at the upper end, and a size having a gap for filling the grout between the inserted reinforcing bars. Is formed.

  FIG. 9 shows the joint structure of the precast reinforced concrete structure. The precast reinforced concrete structure 10 is configured by embedding a sleeve joint 12 disposed perpendicular to the concrete 11 and a reinforcing bar connected to the sleeve joint 12, and the lower end portion of the sleeve joint 12 is made of the concrete 11. Opened on the bottom. Connection ports 12a and 12b are provided at the lower and upper ends of the sleeve joint 12, respectively. The connection port 12a communicates with the grout injection hole 12c, and the connection port 12b communicates with the grout discharge hole 12d.

  The precast reinforced concrete structure 10 is assembled by inserting the reinforcing bar 15 protruding from the floor surface 14 into the sleeve joint 12, and the cloud is injected from the cloud injection hole 12c toward the upper cloud discharge hole 12d. . As for the grout, the work of injecting the grout into dozens of sleeve joints at the construction site is heavy and greatly affects the progress of the construction.

  A grout injection (discharge) port 12 a (12 b) of the sleeve joint 12 communicates with a side surface of the precast reinforced concrete structure 10. As a method of forming a communication hole that connects the grout injection (discharge) port to the side surface of the precast reinforced concrete structure, the applicant has previously inserted the pipe body that expands and contracts and the pipe body, and the inner diameter of the pipe body. A grout casting form was proposed, consisting of a mold core with a large outer diameter.

JP 2012-136864 A

  The grout pouring hole forming mold described in the above publication expands the pipe body by inserting a mold core from one end of the pipe body, and concrete is placed in the expanded state. When the core material for the mold is pulled out after the concrete is solidified, the pipe body contracts to the original size. Since the pipe body is peeled off from the concrete due to the contraction of the pipe body, the pipe body may be pulled out as it is. After the pipe body is pulled out, the grout injection hole 12c and the grout discharge hole 12d are formed.

  However, since the outer diameter of the mold core material is larger than the inner diameter of the pipe body, it is difficult to insert the mold core material, and it is not easy to pull out the mold core material from the pipe body after the concrete is solidified. Therefore, it is preferable to apply grease to the outer periphery of the mold core material in order to make it easier to pull out the mold core material. However, if there is a large amount of grease, grease may leak from the tip of the mold core material into the sleeve joint. There is. Leakage of grease into the sleeve joint is undesirable for concrete.

  The present invention has been made in view of the present situation. When forming a grout pouring hole communicating with a sleeve joint of a precast concrete structure, the grout pouring hole forming is easy to handle and excellent in workability. It aims at providing the formation method of the grout pouring hole using a member and the said member. Further, the grout pouring hole forming member and the member that can easily insert the core member into the elastic tube without using grease and can easily pull out the elastic tube from the solidified concrete. An object of the present invention is to provide a method for forming a grout pouring hole using the above.

  The grout injection hole forming member according to the present invention includes an elastic tube that expands and contracts and a core material that is inserted into the elastic tube, and the hardness of the elastic tube is JIS K 6253 A30-65. The core is formed to have an outer diameter that is the same as or smaller than the inner diameter of the elastic tube. It is preferable to form axial longitudinal grooves or spiral grooves on either the inner peripheral surface of the elastic tube or the outer peripheral surface of the core member. A bulging portion having a diameter larger than the inner diameter of the elastic tube may be formed at the end of the core material, and the elastic tube and the core material may be fixed integrally. Moreover, it is preferable that a core material has flexibility, for example, you may form a helical groove | channel as a wire rope.

  A fixing sleeve may be used as the auxiliary member, and the distal end portion of the elastic tube may be inserted into the fixing sleeve, and the fixing sleeve having the distal end portion of the elastic tube inserted may be fixed to the connection port of the sleeve joint. .

A method for forming a grout pouring hole using the member for forming a grout pouring hole according to the present invention,
A method of forming a grout pouring hole communicating with a sleeve joint of a precast concrete structure, wherein the tip of the elastic tube is screwed into a connection port of the sleeve joint, and then the inner diameter of the elastic tube is the same. , Insert a core material with an outer diameter smaller than the inner diameter of the elastic tube, and fix the tip of the elastic tube by sandwiching it at the connection port between the core material and the sleeve joint. By pulling together with the material, the elastic tube is stretched and separated from the concrete and pulled out to form a grout pouring hole.

  Further, a fixing sleeve is used, and the distal end portion of the elastic tube is inserted into the fixing sleeve, and the fixing sleeve into which the distal end portion of the elastic body tube is inserted is fixed to the connection port of the sleeve joint, and then the elastic sleeve Insert the core material into the body tube, pinch the tip of the elastic body tube between the fixing sleeve and the core material, and after solidifying the concrete, pull the elastic body tube together with the core material to extend the elastic body tube from the concrete. The grout pouring hole may be formed by peeling and pulling.

  In this invention, the outer diameter of the core material constituting the grout pouring hole forming member is smaller than the inner diameter of the elastic tube, so that it is easy to assemble without being forcibly inserted. In addition, since the elastic tube is an elastic body that can be easily expanded and contracted, when the concrete tube is pulled out from the precast concrete structure in which the concrete is solidified, the elastic tube expands and peels off. Therefore, it can be pulled out as a member for forming a grout pouring hole, and is excellent in workability. Further, when the core material is a flexible core material, it can also be formed by a curved injection (discharge) hole. When the fixing sleeve is used, it can be easily attached to the sleeve joint, and leakage of grease into the sleeve joint can be prevented even when grease is applied to the core material.

It is a perspective view for explanation of an elastic tube which constitutes a member for forming a grout pouring hole. FIG. 2 (a) is a front view of a rod-shaped core material having an enlarged diameter portion at one end, and FIG. 2 (b) is a spiral shape on the outer peripheral surface. It is a perspective view of the rope-shaped core material which provided the line | wire. FIG. 3A is a perspective view and FIG. 3B is a cross-sectional view showing a fixing sleeve that constitutes a grout pouring hole forming member. It is sectional drawing which inserted the core material in the elastic body tube. It is sectional drawing of the state which assembled the grout pouring hole formation member to the sleeve joint. It is sectional drawing which shows the other example of the state which assembled the member for grout pouring hole formation to the sleeve coupling. It is sectional drawing for description which shows the state which pulls out the grout pouring hole formation member from the solidified concrete. It is a partial cross section figure of the precast concrete structure in which the grout pouring hole was formed. It is sectional drawing which shows the joining structure of the precast concrete structure which has a grout pouring hole.

  Hereinafter, an embodiment illustrating a grout pouring hole forming member according to the present invention will be described. As shown in FIG. 1, the grout pouring hole forming member 1 is composed of at least an elastic tube 20 and a core member 30 inserted into the elastic tube 20, and the core member 30 is an elastic tube when placing concrete. 20 shapes are retained.

  The elastic tube 20 is a hollow tube which is connected to a connection port of a sleeve joint embedded in a precast concrete structure and forms a grout injection / discharge hole. The elastic tube 20 is an elastic material which can expand and contract, such as rubber. Is formed. Both ends of the elastic tube 20 are opened and assembled by inserting the core member 30 from one end.

  The material of the elastic tube 20 is not particularly limited as long as it can expand and contract, but it is preferably formed of rubber having excellent heat resistance and oil resistance, such as acrylonitrile butadiene rubber (NBR), fluoro rubber, and the like. Further, the elastic tube 20 of the present invention is required to elongate and become thin when pulled out from the concrete, and to be easily peeled off from the concrete. Therefore, the hardness of the material is preferably JIS K 6253 A35-65.

  In addition, the inner peripheral surface of the elastic tube 20 is formed in a concavo-convex shape, and in the illustrated embodiment, a large number of vertical grooves 20a are formed in the inner surface axial direction. Due to the vertical groove 20a, the inner peripheral surface of the elastic tube 20 is not in close contact with the outer peripheral surface of the inserted core member 30, and a gap is formed in the portion of the vertical groove 20a as shown in FIG. It will be.

Further, when grease is applied to the outer peripheral surface of the core member 30 and inserted, the grease enters the gap formed by the vertical groove 20a, so that the core member 30 can be easily inserted and the elastic tube. When the elastic tube is pulled, it slips easily and acts so as to be peeled off, thereby facilitating extraction from the concrete. In addition, when using the said elastic body tube 20, in order to make peeling with concrete easy, it is preferable to apply | coat a mold release agent to an outer peripheral surface.

  In the illustrated embodiment, the concave and convex shape is formed by forming the vertical groove 20a on the inner peripheral surface of the elastic tube 20, but when the pipe body 10 is short (for example, the length dimension is 20 to 40 cm), The uneven shape can be omitted.

  The core material 30 constituting the grout pouring hole forming member 1 may be a solid (solid) rod-like body as long as it has a certain hardness that is not crushed by pressurization during concrete pouring. A hollow pipe may be used. The core material 30 can be formed of a single material of rubber or resin, or can be formed of a composite material having a reinforcing layer inside. The outer diameter of the core member 30 is the same as or smaller than the inner diameter of the elastic tube 20.

  When making the outer diameter of the core material 30 smaller than the inner diameter of the elastic tube 20, it is preferable that it is a magnitude | size which has a 0.1-1 mm clearance gap (refer FIG. 4). By forming the gap in this manner, the compression of the elastic tube is reduced when the concrete is placed, and the elastic tube is easily extended when pulled out and easily peeled off from the concrete.

  FIG. 2 shows the core material 30. A rod-shaped core member 30A shown in FIG. 2A is a solid rod-like body having a smooth outer peripheral surface, and has an enlarged diameter portion 30b at one end. The enlarged diameter portion 30b is provided with a mounting hole 30c for attaching a drawing jig opened at the end face. The rod-shaped core member 30A is inserted into the elastic tube 20, and the end portion of the elastic tube 20 is expanded to the diameter-expanded portion 30b at the end portion and assembled integrally. By covering the end portion of the elastic tube 20 on the enlarged diameter portion 30b, the rod-shaped core member 30A is prevented from falling off the elastic tube 20, and when pulling out, a jig is attached to the mounting hole 30c to attach the rod-shaped core member 30A. Can be easily pulled out from the elastic tube 20.

  The grooved core material 30B shown in FIG. 2 (b) is a core material in which a spiral groove 30d is provided on the outer peripheral surface in a rope shape, and has a certain hardness that is not crushed by pressurization during concrete placement. It is preferable to have flexibility. The grooved core material 30B can be formed of a single material of rubber or resin, or a wire rope.

  The groove shape is not limited to a spiral shape, and may be a longitudinal groove in the axial direction or a transverse groove orthogonal to the axial direction. When the core material 30 is relatively long (for example, the length dimension is 50 cm or more), it is preferable that the core material 30 has flexibility, can be attached in a curved state, and can be easily pulled out after the concrete is solidified. .

  Next, the fixing sleeve 35 which is an auxiliary member of the grout pouring hole forming member 1 will be described. The material of the fixing sleeve 35 shown in FIG. 3 is not particularly limited, but is preferably made of metal. The inner circumferential surface has a retaining projection 35 a, and the inner diameter of the projection 35 a is smaller than the outer diameter of the elastic tube 20. Therefore, when the elastic tube 20 is inserted into the sleeve 35, the diameter is reduced by the convex portion 35 a to prevent the sleeve 35 from coming off, and as described later, when grease is applied to the core member 30, the grease is contained in the sleeve joint 12. It is possible to prevent leakage.

  By providing two or more convex portions 35a, it is possible to further prevent the elastic tube 20 from coming off and prevent grease from leaking. An annular groove may be formed in place of the protrusion 35a in order to prevent the core material from dropping and the grease from leaking. When the sleeve 35 is used, as will be described later, the assembly of the elastic tube 20 and the core member 30 to the sleeve joint 12 is facilitated, and workability is improved.

  Next, a method for forming a grout pouring hole using the aforementioned grout pouring hole forming member will be described. 5 and 6 show a main part in a state in which the elastic tube 20 and the core member 30 are assembled using the fixing sleeve 35 to the sleeve joint 12 before the precast concrete structure is formed. The reinforcing bars fixing the sleeve joint 12 are omitted.

  In FIG. 5, a fixing sleeve 35 </ b> A having a smaller outer diameter than the connection ports 12 a and 12 b is provided at a connection port 12 a serving as a grout inlet and a connection port 12 b serving as a discharge port of the sleeve joint 12 fixed to the reinforcing bars. Is fixed by inserting. In FIG. 6, the connection ports 12a and 12b are fixed by being fitted into the fixing sleeve 35B having a larger inner diameter than the connection ports 12a and 12b.

  The order of assembling the sleeve joint 12 is not particularly limited. For example, first, the fixing sleeve 35A is assembled by inserting the distal end portion of the elastic tube 20 into the fixing sleeve 35 and assembling the elastic tube 20. , 35B may be fixed to the connection ports 12a, 12b. Thereafter, the core member 30 is inserted into the elastic tube 20, and the tip of the core member 30 is projected into the connection ports 12 a and 12 b of the sleeve joint 12.

  Assembling the grout pouring hole forming member 1 to the sleeve joint 12 is easy and very easy to insert because the outer diameter of the core 30 is the same as or smaller than the inner diameter of the elastic tube 20. Assembled into. In addition, since the elastic tube 20 is sandwiched between the fixing sleeve 35 by the insertion of the core member 30, the elastic tube 20 does not fall off.

  When grease is applied to the outer peripheral surface of the core member 30, insertion into and withdrawal from the elastic tube 20 are facilitated. Further, as shown in FIG. 7, the friction between the elastic tube and the core material is reduced when being drawn out after the concrete is solidified, and the elastic tube 20 is elongated to become thin and peel from the concrete 11, so that the drawing can be further facilitated. Become.

  When the fixing sleeve 35 is not used, the elastic tube 20 is inserted into the connection ports 12a and 12b of the sleeve joint 12 so that the distal end of the elastic tube 20 is directly screwed, and then the core member 30 is inserted. do it. Since the elastic tube 20 is sandwiched between the core member 30 and the connection ports 12a and 12b, the elastic tube 20 does not fall off. Further, since the distal end portion of the elastic tube 20 is sandwiched by the core member 30 at the connection ports 12a and 12b, the grease in the sleeve joint 12 may leak even when grease is applied to the outer peripheral surface of the core member 30. Few.

  Even when the elastic tube 20 is mounted in a curved manner in accordance with the arrangement of the sleeve joint 12, the core material 30 having flexibility can be used while being inserted in accordance with the curved shape of the elastic tube. Grout pouring holes can be freely formed.

  Next, after the assembly of the grout pouring hole forming member 1 is completed, concrete may be placed. The placed concrete is cured and solidified for a predetermined period. After the concrete is solidified, the grout pouring hole forming member 1 is pulled out from the sleeve joint 12. As shown in FIG. 7, the elastic tube 20 is formed so as to be easily stretched when the grout pouring hole forming member 1 is pulled out. It will easily peel from the concrete and can be pulled out easily.

  Further, when a release agent is applied to the outer peripheral surface of the elastic tube 20 and grease is applied to the core member 30, the elastic tube 20 has a small frictional resistance and can easily be extended and pulled out easily. Can do. When the outer diameter of the core member 30 is formed slightly smaller than the inner diameter of the elastic tube 20, the compression of the elastic tube is reduced when placing concrete. When the compression becomes smaller, the elastic tube slides better, and the drawing becomes even easier.

  In addition, when longitudinal grooves are formed in the elastic tube 20 and / or the outer peripheral surface of the core member 30, the frictional resistance of each other becomes small, and the elastic tube expands in the same manner as when grease is applied. Making it easy to pull out. The grout pouring hole forming member 1 may be pulled out by first pulling out the core member 30 and then pulling out the elastic tube 20, but it is also possible to pull out the elastic member tube 20 and the core member 30 integrally. .

  When the grout pouring hole forming member 1 is pulled out, as shown in FIG. 8, the grout injection hole 36 and the grout discharge hole 36a are formed. At this time, if the sleeve 35 is assembled and the elastic tube 20 and the core material 30 are pulled out, the sleeve 35 may remain fixed to the sleeve joint 12, but the sleeve 35 is made of metal. There is no particular problem.

1: Grout pouring hole forming mold 20: Elastic tube 30: Core 30A: Rod-shaped core 30B; Grooved core 35: Sleeve

Claims (9)

  A grout pouring hole forming member communicating with a sleeve joint of a precast concrete structure, comprising an elastic tube that expands and contracts and a core material that is inserted into the elastic tube. The grouting hole forming member is characterized in that it is JIS K 6253 A35-65, and the core material is formed to have the same or smaller outer diameter as the inner diameter of the elastic tube.   2. The grout pouring hole forming apparatus according to claim 1, wherein an axial longitudinal concave groove or a spiral groove is formed on one of the inner peripheral surface of the elastic tube and the outer peripheral surface of the core member. Element.   The grouting hole forming member according to claim 1 or 2, wherein a bulging portion having a diameter larger than the inner diameter of the elastic tube is formed at an end portion of the core material.   The grout pouring hole forming member according to claim 1 or 2, wherein the core member has flexibility.   The grout pouring hole forming member according to claim 1 or 2, wherein the core material is a wire rope.   The grout pouring hole forming member according to any one of claims 1 to 4, wherein a fixing sleeve that is fixed to a connection port of a sleeve joint is used as the auxiliary member.   A method of forming a grout pouring hole communicating with a sleeve joint of a precast concrete structure, wherein the tip of the elastic tube is screwed into a connection port of the sleeve joint, and then the inner diameter of the elastic tube is the same. , Insert a core material with an outer diameter smaller than the inner diameter of the elastic tube, and fix the tip of the elastic tube by sandwiching it at the connection port between the core material and the sleeve joint. A method for forming a grout pouring hole, wherein the elastic tube is stretched by pulling with a material, and the grout pouring hole is formed by pulling the elastic tube while peeling from the concrete.   A method of forming a grout pouring hole communicating with a sleeve joint of a precast concrete structure, wherein the tip of the elastic tube is inserted into the fixing sleeve, and the tip of the elastic tube is inserted. Is fixed to the connection port of the sleeve joint, and then the core material is inserted into the elastic tube, the tip of the elastic tube is sandwiched between the fixing sleeve and the core material, and after the concrete is solidified, the elastic tube is cored. A method for forming a grout pouring hole, wherein the elastic tube is stretched by pulling with a material, and the grout pouring hole is formed by pulling the elastic tube while peeling from the concrete.   The method for forming grout pouring holes according to claim 7 or 8, wherein a flexible core material is used as the core material.

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