JPH09203125A - Connection structure of concrete member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection structure capable of easily removing a prestressed member even when one of concrete members is damaged, and capable of being easily arranged in the concrete member of the prestressed member. SOLUTION: In a connection structure, prestressed member insertion ducts 6, 6' are provided in the direction across a joined part of a pair of concrete members 1, 1' arranged opposite to each other, openings 6a, 6a' are provided in parts corresponding to each end part of a prestressed member 5 to be fitted to the prestressed member insertion duct in the concrete member, and the prestressed member is fitted and fixed to the prestressed member insertion duct. The prestressed member insertion duct is formed so as to be expanded toward each opening, the tensile force is introduced in the prestressed member in advance, and a removable tension keeping means to keep the tension is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure for concrete members, and more particularly to a connecting structure formed by embedding a prestressing member into which a tension force is introduced in a concrete member.

[0002]

2. Description of the Related Art Conventionally, as a connecting structure for connecting concrete members in a precast structure or the like, Japanese Patent Application No.
No. -189849 proposes the structure shown in FIG. That is, in the connection structure of FIG. 6, the steel material insertion duct 11 and the lateral hole 13 for temporarily storing the PC steel material 16 slidably are provided in the direction intersecting the edge portion of the concrete member 10 and A duct 11 'into which the PC steel material 16 is slid and inserted is provided at an edge portion joined to the concrete member 10 in a direction intersecting with the edge portion. Further, in the concrete member, vertical holes 1 that open upward are formed at the positions where both ends of the PC steel material 16 are arranged.
2, 12 'are formed, and further, a grout injection hole 13a is formed behind the lateral hole 13. Ducts 11, 1 between the concrete members 10, 10 'thus formed
The PC steel material 16 is inserted into 1 ', the nuts 18 are screwed into both ends of the PC steel material 16 via the bearing plates 17, and the nut 18 is tightened by a torque wrench or the like to introduce a compressive force into the PC steel material 16. To form a connecting structure.

[0003]

In the above-mentioned conventional connecting structure, the PC steel material 16 is arranged in advance in the duct 11 and the lateral hole 13 of the one concrete member 10 so that both concrete members 10 and 10 'are located at predetermined positions. After the arrangement, the PC steel material 16 is moved into the duct 11 'of the concrete member 11' and arranged so as to straddle both concrete members 10 and 10 '. Therefore, one concrete member 1
No. 0 has to be provided with the lateral hole 13, the grout injection hole 13a and the like, and there is a problem that it takes time and cost to form the lateral hole 13 and the grout injection hole 13a.

If only one concrete member is damaged by an external force such as an earthquake, it is difficult to remove only the PC steel material 16 from a sound concrete member. Further, the work of tensioning the PC steel material 16 using a wrench or the like at the construction site is not easy, and a technician with specialized knowledge is required, resulting in an increase in construction cost due to labor costs.

The present invention is intended to solve the above-mentioned problems of the conventional connecting structure, and an object thereof is to insert the prestress member when the prestress is introduced into the joint portion of the concrete member. It is an object of the present invention to provide a connection structure for concrete members, which does not require a duct that does not exist, can easily remove the prestress member even if one of the concrete members is damaged, and can easily regenerate the connection structure.

Another object of the present invention is to provide a concrete member connecting structure in which the prestressing member can be easily arranged in the concrete member.

Still another object of the present invention is to provide a concrete member connecting structure in which a pressure plate for fixing the prestress member to the concrete member can be omitted.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned object, and the gist thereof is to pre-press in a direction intersecting with a joint portion of a pair of concrete members arranged facing each other. A stress member insertion duct is provided, and openings are provided in portions of the concrete member corresponding to both ends of the prestress member inserted into the prestress member insertion duct, and the prestress member is inserted into the prestress member insertion duct. The prestressing member insertion duct is formed so as to expand its diameter toward the respective openings, and the prestressing member has a pre-introduced pulling force detachable. It is held by a tension holding means, and by removing the tension holding means, a compressive stress is introduced into the outer peripheral member. In connection structure of the cleat member.

In the connection structure of concrete members of the present invention, the concrete member means a member formed by containing at least any of concrete, grout and mortar, for example, girders and floor slabs in bridges, floor slabs in paving. Or there is a pontoon.

In the connection structure for concrete members according to the present invention, the prestress member insertion duct may be formed in an arc shape in a direction in which a joint portion of a pair of concrete members intersects. Such an arc shape has an advantage that the prestress member can be easily inserted through the opening after the pair of concrete members are joined.

In the concrete member connecting structure according to the present invention, the prestress member can be formed by using the following PC steel rod unit. That is, P
The C steel rod unit has a tubular tensile PC steel rod with at least one end open, a reaction force PC steel rod inserted inside the tension PC steel rod, and a reaction force to the reaction force PC steel rod. Above-mentioned tension P
A tensile force may be introduced to the C steel bar to form a tension holding member that holds this tensile force.

[0012] A screw thread may be formed on the outer surface of the tensile PC steel rod, and by forming the screw thread in this way, concrete attached to the outer surface of the tensile PC steel rod or the backfill grout. Adhesion performance between the mortar as a material and the tensile PC steel rod can be improved. Further, such an improvement in adhesion performance can prevent a phenomenon in which only the tensile PC steel rod is pulled out even when a compressive stress is introduced from the tensile PC steel rod to the concrete member on the outer periphery thereof. Therefore, it becomes possible to fix by simply inserting the tensile PC steel rod into the prestressing member insertion duct and filling the inside with grout such as mortar or concrete, and the support provided at both ends of the conventional tensile PC steel rod. The pressure plate can be omitted.

In order to further explain the effect of the screw thread on the outer surface of the tensile PC steel rod, for example, when a conventional type PC steel rod having a diameter of 32 mm is used, a pressure plate of 16 × 16 cm is required. In this case, the concrete member was formed with a recess for embedding a bearing plate of 16 × 16 cm. It is preferable to make the cross section as small as possible in order to reduce the structural cross section of the concrete member and reduce the structural yield strength of the concrete member. Therefore, if a screw thread is provided on the outer surface of the tensile PC steel rod, the pressure bearing plate can be omitted, and thus the cross section of the recess for fixing the tensile PC steel rod can be made extremely smaller than the conventional cross section. There is an advantage.

Since the reaction force PC steel rod takes a reaction force when the tensile force is introduced and held in the tensile PC steel rod, the tensile PC steel rod is
It is housed inside a steel rod and contributes to the tension of the entire tensile PC steel rod.

The tension holding member holds the tension PC steel rod under tension by applying a reaction force to the reaction PC steel rod. For example, male screws are formed on both ends of the tension PC steel rod. Incidentally, it is possible to use an appropriate one such as a nut or a bolt which is screwed to the male screw and can hold the tensile PC steel rod in tension while pressing the reaction PC steel rod with a jack device or the like.

According to this aspect, prestress can be easily introduced into the concrete member by the pretensioning method. Further, as described above, when the PC steel rod unit is used when fixing at least a pair of concrete members, each cement hardened product can be adhered to the entire tensile PC steel rod to be firmly integrated with each other. Prestress can be introduced into the concrete member to easily fix it.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings, but the present invention is not limited thereto.
FIG. 1 is a cross-sectional view showing a concrete member connecting structure of the present invention, FIG. 2 is a perspective view of a formwork used when constructing the concave portions 3 and 3 ′ in FIG. 1, and FIG. FIG. 4 is a partially enlarged perspective view of the sheath tube 6, FIG. 4 is a cross-sectional layout view showing the layout of the reinforcing bars 7 in FIG. 1, and FIG. 5 is a PC steel rod unit including the prestressing member 5 in FIG. FIG.

In FIG. 1, sheath pipes 6 and 6'as prestressing member insertion ducts are respectively buried in a direction intersecting with a joint 8 of a pair of concrete members 1 and 1'opposed to each other. In addition, the sheath tubes 6 and 6'are arranged so as to communicate with each other. Further, on the surfaces of the concrete members 1 and 1 ', concave portions 3 and 3'communicating with the openings 6a and 6a' at both ends of the communicating sheath tubes 6 and 6'are formed, respectively. The prestressing member 5 is inserted and fixed inside.

As shown in FIGS. 1 and 3, the sheath tubes 6 and 6'are formed so as to expand in diameter toward the openings 6a and 6a ', respectively, and have an arc shape (for example, radius). Is used to form an arc of 1500 mm). A pre-stress member 5 is inserted into the sheath tubes 6 and 6 ′ and filled with non-shrink mortar 4.

The recesses 3 and 3'are formed on the surfaces of the concrete members 1 and 1'by arranging the mold 9 as shown in FIG. 2 at both ends of the communicating sheath tubes 6 and 6 '.

In addition, on the outer circumference of the sheath tubes 6 and 6 ',
Reinforcing bars for abdominal pressure by the prestressing member may be provided. That is, in FIG. 1, for convenience, the spiral muscles 7a and the abdominal muscles 7b, which are illustrated only in the concrete member 1 ', can be provided on the outer periphery of the sheath pipes 6, 6'of the concrete members 1, 1'as reinforcement muscles.

The prestressing member 5 is formed by using a PC steel rod unit having an arc shape similar to that of the sheath tubes 6 and 6'as shown in FIG. However, in FIG. 5, for convenience, the PC steel rod unit 20 is illustrated in a linear shape, and the configuration and usage thereof will be described. In FIG. 5, the PC steel rod unit 20 includes a hollow PC steel rod 21 as a tubular tensile PC steel rod having at least one end opened,
A solid PC steel rod 22 as a reaction force PC steel rod housed inside the hollow PC steel rod 21 so as to be detachable, and the hollow PC steel rod 21.
Each member (23a, 23a ', 23) described later for applying a reaction force to the steel rod 22 to hold the hollow PC steel rod 21 under tension.
b'23c) and the tension holding member 23 and the main part is formed, and the nut 24 for fixing is hollow P.
It is screwed onto the C steel rod 22.

The hollow PC steel rod 21 is directly embedded in the sheath pipes 6, 6'to introduce prestress to the concrete members 1, 1 ', and is formed into a cylindrical shape as described above. A male screw is engraved on the outer circumference of both ends. In addition, the solid PC steel rod 22 is a hollow P
It is used to take a reaction force when a tensile force is introduced into the C steel rod 21. Further, the cap nut 23a 'as the tension holding member 23 is screwed into the male screw at one end of the hollow PC steel rod 11, while the nut 23a is screwed into the male screw at the other end. Further, the piece 23c is a hollow PC steel rod 11
The solid PC steel rod 22 inserted therein is inserted into the nut 23a so as to come into contact with the solid PC steel rod 22.
A bolt 23b is screwed into a screw thread on the inner circumference of the nut 23a so as to be contained therein.

In the PC steel rod unit 20 having the above structure shown in FIG. 5, a tensile force is introduced into the hollow PC steel rod 11 in advance in a factory or the like. That is, pressing force in the arrow X direction is applied to the solid PC steel rod 22 via the top 23c by a jack device or the like, and the solid PC steel rod 22 is pushed into the hollow PC steel rod 21. Then, the bolt 23b is screwed into the nut 23, and the pressed solid PC steel rod 22 is fixed in a compressed state via the top 23c. The solid PC steel rod 22 thus compressed by the pressing force tries to restore its original length by abutting the tip of the solid PC steel rod 22 on the cap nut 23a ′ and the abutting end on the top 23c. Due to the restoring force of the solid PC steel rod 22, a tensile force is introduced into the hollow PC steel rod 21 via the cap nut 23a 'and the tension holding members 23c, 23b, 23a.

Next, the construction procedure of the concrete member connection structure of the present invention will be described. First, a pair of concrete members 1 and 1'are arranged facing each other. Recesses 3 and 3'are formed in advance in the concrete members 1 and 1 ', and sheath tubes 6 and 6'are also embedded therein.

Next, the PC steel rod unit 20 is inserted into the sheath tubes 6 and 6 ', and the grout material 4 is further filled into the sheath tubes 6 and 6'and the joint 8. At this time, the PC steel rod unit 20 is arranged at a position such that the grout material 4 is attached to the cap nuts 23a ′ and the nuts 24 to be integrated, and the grout material 4 is not attached to the nut 23a. If necessary, a release agent may be applied to the inner surfaces of the sheath tubes 6 and 6'in advance. If the release agent is applied in this manner, the grout material 4 can be easily removed from the sheath tubes 6 and 6'when repairing. It has the advantage that it can be removed.

After the grout material 4 in the sheath tubes 6 and 6'is hardened, the nut 23a of the PC steel rod unit 20 is removed and the solid PC steel rod 22 is pulled out from the inside of the hollow PC steel rod 21. As a result, the tensile force acting on the hollow PC steel bar 21 from the solid PC steel bar 22 is released, so that the hollow P
The C steel rod 21 shrinks and introduces prestress (compressive stress) into the concrete members 1 and 1'through the surrounding grout material 4 and the sheath tubes 6 and 6 '. After introducing the prestress, the recesses 3 and 3 ′ of the concrete members 1 and 1 ′ are filled with the grout material 2 to complete the connection structure.

In the connection structure of concrete members formed as described above, a PC steel rod having a hollow PC steel rod 21 to which a tensile force has been introduced in advance and a nut 23a, a bolt 23b and a top 23c as a tension holding means. Unit 20
Since the construction is performed by using, the prestress can be introduced into the connecting portion of the concrete member at the construction site by simply removing the nut 23a, the bolt 23b and the top 23c as the tension holding means.

Further, in the concrete member connecting structure of the present invention, since the sheath pipes 6 and 6'are formed so as to expand in diameter toward the respective openings, for example, only one concrete member due to an earthquake or the like. Even when damaged, the prestress member can be easily pulled out from the sheath tube. In other words, remove the damaged concrete members, expose the joints of sound concrete members,
If a pressing force is applied from the sheath tube opening of this joint toward the expanded diameter opening, the grout material 4 and the hollow P inside the sheath tube
The C steel rod 21 can be extruded through the enlarged diameter opening.
Therefore, by arranging the hollow PC steel rod 21 again using the PC steel rod unit 20 in this sheath pipe, the connection structure of the concrete members can be easily regenerated. At this time, if the sheath tube has a gentle arcuate shape as shown in FIG. 1, the work of extruding the grout material 4 and the hollow PC steel rod 21 from the inside of the sheath tube can be further facilitated.

[0030]

In the connecting structure for concrete members of the present invention, a tensile force is introduced in advance, and this tensile force is held by the detachable tension holding means. Since construction is performed using a prestressing member that can introduce compressive stress to the member, at the construction site, simply remove the tension holding means,
Prestressing can be introduced into the connection of concrete members.

Further, in the concrete member connecting structure of the present invention, since the prestressing member insertion duct is formed so as to expand its diameter toward each opening, for example, even when only one concrete member is damaged. ,
If a pressing force is applied from the sheath tube opening at the joint to the expanded diameter opening, the prestress member or the grout material can be easily pulled out from the sheath tube. Therefore, if the sheath tube is reused and the prestress member is disposed therein, the connection structure of the concrete members can be easily regenerated.

Further, the prestressing member insertion duct is
Since it is formed to expand toward both openings, a prestressing member is inserted into the duct to inject grout material, and a compressive force is introduced from the prestressing member to the concrete member through the grout material. Then, since the grout material is compressed in the direction in which the diameter of the duct is reduced, there is an advantage that the grout material acts like a wedge in the duct to improve the adhesion performance with the duct.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a concrete member connection structure of the present invention.

FIG. 2 is a perspective view of a formwork used when constructing a recess in FIG.

FIG. 3 is a partially enlarged perspective view of the sheath tube in FIG.

4 is a cross-sectional layout view showing the layout of reinforcing bars in FIG. 1. FIG.

5 is a partial cross-sectional view of a PC steel rod unit including the prestressing member in FIG.

FIG. 6 is a sectional view showing a conventional example.

[Explanation of symbols]

 1, 1'Concrete member 5 Pre-stress member 6, 6'Sheath tube (pre-stress member insertion duct) 6a, 6a 'opening 21 Hollow PC steel rod (pre-stress member) 23a Nut (tension holding means) 23b Bolt (tension holding) Means) 23c Top (tension holding means) 23a 'Cap nut (tension holding means)

Claims (1)

[Claims] 1. A prestressing member inserting duct is provided in a direction intersecting with a joint portion of a pair of concrete members arranged to face each other, and a prestressing member inserting duct is fitted in the concrete member. Opening is provided in the parts corresponding to both ends of the stress member,
A connecting structure in which a prestressing member is inserted and fixed in the prestressing member insertion duct, wherein the prestressing member insertion duct is formed so as to expand in diameter toward the respective openings. The tensile force introduced in advance in the stress member is held by a detachable tension holding means, and by removing the tension holding means, a compressive stress is introduced into the outer peripheral member. .