JP2020147981A - Concrete structure connecting body and construction method of concrete structure connecting body - Google Patents

Abstract

To provide a technique capable of adding prestress to a tendon according to an operation to connect concrete decks.SOLUTION: A tendon 2 is disposed in a concrete deck 1. A concrete deck connecting body is formed by connecting the concrete decks to each other. Multiple metal fittings are disposed at an end of the concrete deck 1. When the concrete decks 1 and 1 face each other, metal fittings 3 and 3 face each other. A joint 4 is inserted in the metal fittings 3 and 3 facing each other to connect the concrete decks 1 and 1. An anchorage 6 is disposed on an end of the tendon 2. The anchorage 6 anchors the tendon 2 to the metal fitting 3 when prestress is applied to the tendon 2. Operation conversion means 7 converts an insertion operation of the joint 4 to a tensioning operation of the tendon 2. Thereby, connection and prestress addition are simultaneously carried out.SELECTED DRAWING: Figure 3

Description

The present invention relates to a concrete structure connection composed of a plurality of concrete structures into which prestress is introduced, and more particularly to a concrete structure connection having a connection mechanism by a joint. A concrete plate bridge is an example of a concrete structure.

There are asphalt pavement and concrete pavement. Concrete pavement is used when durability is required, such as pavement at airports and harbors, and pavement at intersections on roads. There are two types of concrete pavement: cast-in-place concrete and concrete slabs. Concrete slabs can be manufactured at the factory. From the viewpoint of rapid construction and quality maintenance, concrete slabs are advantageous.

When a load acts on the concrete slab, tensile stress acts on the concrete, causing cracks to occur. On the other hand, in the concrete floor slab on which the tension material is arranged, the occurrence of cracks can be suppressed by introducing prestress (Patent Document 1). As a result, the amount of reinforcing bars in the concrete slab can be reduced and the concrete slab can be made thinner. In principle, a fixing tool function is required to fix the tension material.

By the way, in pavement using concrete slabs, problems often occur at connecting points between concrete slabs. For example, if the joints open and water permeates the roadbed and the roadbed contains a large amount of water and a large load is repeatedly applied, the pumping phenomenon causes the fine particles of the roadbed to flow out and create cavities under the pavement. Occurs. Concrete slabs lose their bearing capacity and cause damage. In addition, minute deformation of the concrete floor slab near the joint may contribute to noise.

On the other hand, a technique for connecting concrete floor slabs with a special joint has been proposed (Patent Document 2). For example, in a cotter type joint, prestress is introduced to the connecting portion by providing a taper on the side surface of the joint and the inner wall surface of the receiving metal fitting, and inserting and fixing the joint to the receiving metal fitting. As a result, the concrete slabs are securely connected to each other.

Japanese Unexamined Patent Publication No. 2004-224633 Japanese Unexamined Patent Publication No. 2001-214964

Although the concrete slab itself into which the above prestress is introduced has an excellent function, there is a possibility that problems may occur at the connecting points (so-called joints). That is, it is not a single connected structure. If a connecting function such as a cotter type joint is added to the concrete floor slab into which the above prestress is introduced, it is considered that a single connecting structure can be obtained.

However, when combining the fixing tool function and the connecting function in the concrete floor slab, the specific configuration of how to combine them has not been determined. Connection by tie bar is common.

The inventor of the present application has intended to add a completely new function when combining the fixing tool function and the connecting function in the concrete floor slab.

The present invention solves the above problems, and an object of the present invention is to provide a technique capable of applying prestress to a tension material in association with an operation of connecting concrete structures.

The present invention that solves the above problems is a concrete structure connecting body formed by connecting concrete structures in which tension members are arranged. A plurality of receiving metal fittings provided at the end of the concrete structure, joints inserted into the opposing metal fittings to connect the concrete structures to each other, and the tensioning material when prestress is introduced into the tensioning material. Is provided with a fixing means for fixing the metal fitting to the metal fitting, and an operation converting means for converting the insertion operation in the joint into the tensioning operation in the tension material.

The motion conversion means converts the insertion motion in the joint into the tension motion in the tension material. As a result, when the joint is inserted and fixed to the bracket, connection and prestress addition are performed at the same time. As described above, the present invention is excellent in workability.

In the above invention, preferably, the receiving metal fitting includes a flat opening into which a part of the joint is inserted, a facing surface portion facing the receiving metal fitting of the adjacent concrete structure, and a slit provided in the facing surface portion. It has the facing surface portion and the end side surface portion facing each other inside the receiving metal fitting. The inner wall of the side surface portion of the end has a curved surface portion. The motion conversion means is a rotary arc body that can slide along the curved surface portion of the side surface portion of the metal fitting end, and is pressed by the joint insertion at one end of the rotary arc body main body and the rotary arc body main body. At the other end of the pressing receiving portion and the rotating arc body main body, there is a fixing interposing portion interposed between the fixing means and the receiving metal fitting.

The insertion motion is converted into a tension motion through the rotation of the rotating arc body body.

In the above invention, preferably, when the pressing receiving portion is pressed in the rotating arc body, the rotating arc body main body slides and rotates along the curved surface portion of the side surface portion of the metal fitting end, and the fixing intervention is performed. The portion moves in the tension direction, and prestress is applied to the tension material.

The insertion motion is converted into a tension motion through the rotation of the rotating arc body body.

In the above invention, preferably, the fixing interposition portion is provided on the end face of the rotating arc body main body in a curved surface shape, and the tip of the fixing means can slide along the curved surface of the fixing intervening portion.

The tip of the fixing means rotates in the opposite direction in conjunction with the rotation of the rotating arc body body. As a result, the straightness of the tension material is maintained.

In the above invention, preferably, the pressing receiving portion extends from the rotating arc body main body to the joint side.

As a result, the lower surface of the joint presses the pressing receiving portion of the motion conversion means.

In the above invention, preferably, the joint and the opposing metal fitting form a cotter type joint structure.

As a result, prestress is introduced into the connecting mechanism along with the connecting.

The concrete structure is a concrete slab.

As a result, the concrete slabs are securely connected, and the connecting structure functions as one large rigid flat plate.

The present invention that solves the above problems is a method for constructing a concrete structural connection. At least two concrete structures into which prestress is introduced by the tension material are arranged so as to face each other, a joint is inserted into the facing metal fittings, and the force for inserting the joint is transmitted to the motion conversion means. By moving the motion changing means in the tensioning material tension direction, the fixing means is moved in the tensioning material tensioning direction, and prestress is applied to the tensioning material.

The present invention that solves the above problems is a tension addition structure that applies prestress to a tension material arranged in a concrete structure. A metal fitting provided at the end of the concrete structure, a fixing means for fixing the tension material to the receiving metal fitting when prestress is introduced into the tension material, and an operation of converting an external operation into the tension material tension operation. It is provided with a conversion means. The metal fitting has a flat opening capable of external operation and a fixing surface that receives a tension force by the fixing means. The inner wall of the fixing surface has a curved surface portion. The motion conversion means is a rotary arc body slidable along a curved surface portion of the fixing surface, and is a pressing receiving portion that receives a push by the external motion at one end of the rotary arc body body and the rotary arc body body. And at the other end of the rotating arc body main body, there is a fixing intervening portion interposed between the fixing means and the receiving metal fitting.

According to the present invention, prestress can be added as the concrete structures are connected. As a result, the workability is excellent.

The prestress addition includes a case where the prestress is introduced into the tension material to which the prestress is not introduced and a case where the prestress of the tension material to which the prestress is introduced in advance is increased.

Schematic perspective view and bar arrangement of concrete plate slab Schematic plan view of the connected structure Sectional drawing which shows connection mechanism and incidental structure Perspective view showing a connecting mechanism and ancillary configurations An exploded perspective view showing the connection mechanism and its peripheral configuration Partial cross-sectional perspective view showing the detailed configuration of the bracket Schematic perspective of the joint Schematic perspective view of motion conversion means Operation explanatory diagram of the operation conversion means Operation flow diagram of operation conversion means Sectional drawing which concerns on modification of motion conversion means Operational illustration of the connecting mechanism (cotter type joint structure) Schematic perspective view of a partial cross section showing a modified example of the fixing tool function of the bracket. Schematic configuration of a partial cross section according to an application example to a box culvert

~
~ Concrete plate bridge and connecting structure ~

FIG. 1A is a schematic perspective view of the concrete floor slab 1. FIG. 1B is a bar arrangement diagram of the concrete floor slab 1. The illustrated example is used in relatively large areas such as airport parking lots and taxiways. For example, it is a flat plate having a width of about 2400 mm, a height of 15,000 mm, and a thickness of 240 mm. The road slab has a width of about 1800 mm, a vertical width of 5000 mm, and a thickness of about 180 mm. Concrete has a strength of 20-60 N (Newton) / cm2. Reinforcing bars are arranged to ensure rigidity.

A plurality of receiving metal fittings 3 are provided at the ends (four sides) of the concrete floor slab 1. In the illustrated example, the metal fittings 3 are embedded at 20 locations in the long side direction and 3 locations in the short side direction, for a total of 46 locations.

Further, a tension member 2 is arranged between the metal fittings 3 and 3. There are cases where prestress is introduced at the factory and cases where prestress is not introduced at the factory (details will be described later).

FIG. 2 is a schematic plan view of the connecting structure 10. A roadbed is provided, and a plurality of concrete slabs 1 are laid out in a plane on the roadbed while maintaining a joint spacing of a predetermined width. With the concrete floor slabs 1 and 1 arranged, the metal fittings 3 and 3 face each other. The receiving metal fittings 3 and 3 and the joint 4 form a connecting mechanism 5.

Adjacent concrete slabs 1, 1 are securely and firmly connected to each other via the connecting mechanism 5, and the connecting structure 10 is formed. The connecting structure 10 functions as one large rigid flat plate.

~ Outline of connection mechanism ~
FIG. 3 is a cross-sectional view showing the connecting mechanism 5 and the incidental configuration. FIG. 4 is a perspective view showing the connecting mechanism 5 and the incidental configuration. FIG. 5 is an exploded perspective view showing the configuration of the connecting mechanism 5 and its surroundings.

The connecting mechanism 5 is composed of receiving metal fittings 3 and 3 and a joint 4. As an incidental configuration inside the bracket 3, when prestress is introduced into the tension member 2, the fixing tool 6 that fixes the tension member 2 to the bracket 3 and the joint 4 insertion operation are converted into the tension member 2 tension operation. The motion conversion means 7 is provided.

Hereinafter, each configuration of the metal fitting 3, the joint 4, the connecting mechanism 5, the fixing tool 6, and the motion conversion means (rotary arc body) 7 will be described in detail.

~ Brackets and fittings ~
FIG. 6 is a partial cross-sectional perspective view showing a detailed configuration of the bracket 3.

In the illustrated example, the bracket 3 has a substantially rectangular parallelepiped shape, and has a flat opening 31, four side surface portions 32 to 35, and a bottom surface portion 36.

The side surface portion (opposing surface portion) 32 faces the concrete floor slab receiving metal fitting to be connected. The side surface portion (wife side surface portion) 33 faces the side surface portion 32 on the side opposite to the side facing the concrete floor slab receiving metal fitting to be connected. The side surface portions 34 and 35 face each other in a direction orthogonal to the opposite direction of the side surface portions 32 and 33.

The side surface portions 32 to 35 are erected from each side of the bottom surface portion 36, and the range surrounded by the upper edges of the side surface portions 32 to 35 forms the flat opening portion 31.

The side surface portion 32 is provided with a slit 37 continuous with the flat opening portion 31 in the vertical direction shown in the drawing. A bolt hole 38 is provided on the bottom surface portion 36.

The inner wall of the side surface portion (end side surface portion) 33 has a curved surface portion 131.

The metal fitting 3 of the present application is characterized by having a joint receiving function and a fixing tool function. In the joint receiving function, the flat opening 31 and the slit 37 are received so as to lock the joint 4. In the fixing tool function, a hole is provided in the side surface portion 33, and the tension material 2 inserts the hole. A fixing tool 6 is provided at the end of the tensioning member 2, and is fixed to the side surface 33 via the rotating arc body 7.

FIG. 7 is a schematic perspective view of the joint 4. The joint 4 has a dumbbell shape in a plan view. That is, it has a connecting portion 42 that connects the two end portions 41, 41 and the two end portions 41, 41. Two holes are provided in each of the ends 41 and 41, and the four bolts 43 insert the holes.

The two brackets 3 and 3 face each other via joints and facing surfaces 32 and 32. One joint end 41 is inserted into the flat opening 31 of one receiving metal fitting 3, and the other joint end 41 is inserted into the flat opening 31 of the other receiving metal fitting 3. The joint connecting portion 42 is inserted into the space corresponding to the slits 37 and 37. The joint end portions 41, 41 are locked to the facing surface portions 32, 32.

The bolt 43 is screwed into the bolt hole 38. As a result, the joint 4 is fixed in the metal fittings 3 and 3, and the connecting mechanism 5 is formed.

Further, a lid is attached to the opening on the upper surface of the metal fittings 3 and 3 to cover the connecting mechanism 5.

Joints are provided at appropriate intervals between the brackets 3 and 3. The joint may be formed by injecting grout, or a resin joint material may be inserted.

~ Rotating arc body and fixing tool ~
FIG. 8 is a schematic perspective view of the motion conversion means 7. The motion conversion means 7 is a rotating arc body. A pressing receiving portion 72 and a fixing interposing portion 73 are formed on the rotating arc body main body 71.

In the illustrated example, the rotating arc body body 71 is a semicircular tubular body. It may be a hemisphere. It suffices to have a surface on which the pressing receiving portion 72 is formed on one end side of the arc and a surface on which the fixing interposing portion 73 is formed on the other end side of the arc.

The rotating arc body main body 71 has a shape (curved surface shape) corresponding to the curved surface portion 131 of the inner wall of the metal fitting side surface portion 33, and is slidable along the curved surface portion 131.

The push receiving portion 72 extends in a rod shape from one end surface of the rotating arc body main body 71 to the joint 4 position side. The tip end side of the push receiving portion 72 has a flat portion so as to receive the pressing of the lower surface of the joint 4 by inserting the joint 4.

The fixing interposition portion 73 is provided on the other end surface of the rotating arc body main body 71 in a hemispherical recess shape. It may have a hemispherical dome shape, a semi-cylindrical depression shape, or a semi-cylindrical protrusion shape. The fixing interposing portion 73 is interposed between the fixing tool 6 and the metal fitting 3. A hole is provided in the central portion of the fixing interposition portion 73.

Returning to FIGS. 3 to 5, the tension material 2 and the fixing tool 6 will be described.

The tension material 2 is arranged in the concrete floor slab 1. The tension material 2 inserts a hole in the side surface portion 33 of the receiving metal fitting and a hole in the fixing interposing portion 73. A fixing tool 6 is provided at the end of the tension material 2.

The tip 61 of the fixing tool 6 is formed in a hemispherical dome shape so as to correspond to the hemispherical depression of the fixing interposition portion 73. The fixing tool tip 61 is slidable along the curved surface of the fixing interposition portion 73.

The tension material 2 may be a stranded wire and the fixing tool 6 may be a wedge type, or the tension material 2 may be a steel rod and the fixing tool 6 may be a fixing nut. A steel material is generally used as the tension material 2, but an alternative product such as FRP may be used.

~ Behavior conversion ~
FIG. 9 is an operation explanatory view of the operation conversion means 7. FIG. 10 is an operation flow diagram of the operation conversion means 7.

Step 1: With the concrete floor slabs 1 and 1 arranged, the metal fittings 3 and 3 face each other, and the joint 4 is inserted from above. As a result, the connecting mechanism 5 is formed. Further, if the connecting mechanism 5 has a cotter type joint structure, prestress is introduced so that the concrete floor slabs 1 and 1 attract each other.

Due to the bolt screwing structures 38 and 43, the joint 4 gradually moves downward. Along with this, the lower surface of the joint 4 presses the pressing receiving portion 72 of the motion converting means 7.

Step 2: When the pressing receiving portion 72 is pressed by the motion converting means 7, the rotating arc body main body 71 slides along the curved surface portion 131 of the inner wall of the receiving metal fitting side surface portion 33 and rotates counterclockwise as shown. Along with this, the fixing interposition portion 73 also rotates. The fixing interposition portion 73 moves to the joint side by rotation.

Step 3: When the fixing interposition portion 73 moves to the joint side, the fixing tool 6 moves to the joint side (tension direction side). Along with this, the tension material 2 is pulled, and prestress is added to the tension material 2. If the prestress is not introduced before the main operation, the prestress is introduced into the tension member 2. If prestress is introduced in advance before the main operation (for example, at the time of factory shipment), the prestress of the tension material 2 increases.

That is, the pressing (step 1) by inserting the joint 4 is converted into the tension material 2 tension (step 3) via the rotation of the rotating arc body body 71 (step 2).

~ Fixing tool tip and fixing intervening part operation ~
In the above embodiment, the fixing interposition portion 73 is provided in the rotating arc body main body 71 in a hemispherical recess shape, and the fixing tool tip 61 is formed in a hemispherical dome shape to correspond to irregularities (see FIG. 5 and the like).

When the operation conversion is performed in this state, the fixing means tip 61 is formed by the fixing interposition portion 73 in conjunction with the rotation arc body main body 71 sliding along the curved surface portion 131 of the inner wall of the metal fitting side surface portion 33. It slides in the opposite direction along the curved surface.

Therefore, it is suppressed that the arrangement direction of the tension member 2 is extremely bent with the rotation of the rotating arc body main body 71, and the straightness of the tension member 2 is maintained. As a result, the tension force of the tension member 2 is surely transmitted to the metal fitting 3.

~ Return deterrent part ~
In the above embodiment, the return suppression units 132 and 133 may be further provided.

In FIG. 6, the curved surface portion 131 of the inner wall of the metal fitting side surface portion 33 is lowered by one step from the bottom surface portion 36 and is continuous with the bottom surface portion 36. A return restraint portion 132 is formed at the step portion.

If prestress is introduced into the tension member 2 in advance before the motion conversion, the rotating arc body 71 tries to rotate (clockwise in FIG. 9) due to the prestress, but the end of the rotating arc body 71 returns. It is locked to the restraining portion 132, and the rotation of the rotating arc body main body 71 is suppressed (see step 1 in FIG. 10).

In FIG. 5, holes are provided in the upper portion of the metal fitting 3 and the upper portion of the rotating arc body main body 71, respectively. The return restraint portion 133 is inserted into the hole of the metal fitting 3 and the hole of the rotating arc body main body 71. In the illustrated example, the return restraint unit 133 is a pin.

In the above, the case where the prestress is introduced in the tension material 2 before the motion conversion and the case where the prestress is not introduced in the tension material 2 before the motion conversion are mentioned. In either case, Prestress occurs after the motion conversion. The rotary arc body 71 tries to rotate (clockwise in FIG. 9) due to prestress, but the end of the rotary arc body 71 is connected to the metal fitting 3 via the return restraint portion 133, and the rotary arc body 71 Rotation is suppressed (see step 3 in FIG. 10).

It should be noted that the induction of rotation of the rotating arc body body 71 by prestress after the motion conversion acts to lift the joint 4 from below, which is not preferable for the connecting mechanism 5. The return restraining unit 133 suppresses the rotation induction of the rotating arc body main body 71, thereby ensuring the connection by the connecting mechanism 5.

~ Motion conversion means modification example ~
FIG. 11A is a cross-sectional view of a modified example 1 of the motion conversion means 7. The push receiving portion 72 in the above embodiment extends in a rod shape from one end surface of the rotating arc body main body 71 to the joint 4 position side (see FIG. 8).

On the other hand, in the modified example 1, the pressing receiving portion 72 is provided on one end surface of the rotating arc body main body 71 in a hemispherical dome shape. On the other hand, the lower portion of the outer wall of the side surface portion 33 of the bracket is provided with a taper that contracts inward in the direction from top to bottom (widens outward in the direction from bottom to top).

When the joint 4 is inserted into the metal fittings 3 and 3, the lower taper of the metal fitting 3 comes into contact with the hemispherical dome shape of the pressing receiving portion 72. As a result, the joint 4 presses the pressing receiving portion 72.

Further, a top is provided on the upper part of the taper, and a reverse taper that contracts inward in the direction from the bottom to the top is provided.

When the hemispherical dome shape of the push receiving portion 72 exceeds the top, even if the rotation of the rotating arc body 71 (clockwise in FIG. 9) is induced by the prestress after the motion conversion, the hemispherical dome shape of the push receiving portion 72 is induced. Is hard to return beyond the top. Further, the rotation induction of the rotating arc body main body 71 by the prestress after the motion conversion acts to lift the joint 4 from diagonally downward (diagonally lateral direction). The influence on the connecting mechanism 5 in the above embodiment is alleviated. That is, the top in the first modification functions as a return restraint.

FIG. 11B is a cross-sectional view of a modified example 2 of the motion conversion means 7. The rotating arc body body 71 in the above embodiment is a semi-cylindrical body (or hemisphere) (center angle of the arc is approximately 180 degrees) (see FIG. 8).

On the other hand, in the modified example 2, the rotating arc body main body 71 is a cylindrical body (or 3/4 sphere) having a central angle of about 270 degrees of the arc. Further, the pressing receiving portion 72 is provided on one end surface of the rotating arc body main body 71 in a hemispherical dome shape. On the other hand, a recessed hemisphere is provided in the lower part of the bottom surface portion 36 of the bracket.

When the joint 4 is inserted into the brackets 3 and 3, the recessed hemisphere at the bottom of the bracket bottom surface 36 comes into contact with the hemispherical dome shape of the pressing receiver 72. As a result, the joint 4 presses the pressing receiving portion 72.

Since the pressing structure is a spherical surface and a spherical surface, the pressing structure is maintained even if the rotating arc body main body 71 is rotated (counterclockwise in FIG. 9) by pressing.

It may be a pressing structure with a curved surface and a curved surface. Further, the unevenness relationship may be reversed. That is, the hemispherical dome shape at the lower part of the bottom surface portion 36 of the receiving metal fitting comes into contact with the hemispherical recess shape of the pressing receiving portion 72.

Further, in the first and second modifications, the joint 4 has a horseshoe shape so that the joint 4 can include the fixing tool 6.

~ Cotter type joint structure ~
Even if the connecting mechanism 5 does not have a cotter-type joint structure, the motion conversion means 7 operates (pressing → tension), but it is more preferable that the connecting mechanism 5 has a cotter-type joint structure. Note that FIGS. 3 to 10 show a cotter type joint structure.

The cotter type joint 4 is formed with tapers 44, 44 at two ends 41, 41 so as to be separated from each other in the direction from top to bottom. The tapers 44, 44 form a female wedge. The inner walls of the side surfaces 32, 32 of the brackets 3 and 3 are also provided with tapers 39, 39 so as to be separated from each other in the direction from top to bottom. The tapers 39, 39 form a male wedge. The female wedge shape due to the tapers 44 and 44 corresponds to the male wedge shape due to the tapers 39 and 39.

FIG. 12A shows a state before the cotter type joint 4 is inserted, and FIG. 12B shows a state after the cotter type joint 4 is inserted and screwed with a bolt.

When the cotter type joint 4 is inserted into the metal fittings 3 and 3, the male wedge shape due to the tapers 39 and 39 bites into the female wedge shape due to the tapers 44 and 44. As a result, prestress is introduced between the metal fittings 3 and 3 so as to attract each other. Since the bolts 43 and 43 are screwed into the bolt holes 38 and 38, the wedge does not come off. A strong connecting mechanism 5 is formed.

~ Example of deformation of bracket fixing tool function ~
FIG. 13 is a schematic perspective view of a partial cross section showing a modified example of the fixing tool function of the receiving metal fitting 3. In the above embodiment, one tension member 2 is fixed to the receiving metal fitting 3, and the fixing interposition portion 73 is provided at the center of the end face of the rotating arc body main body 71 (see FIG. 5).

On the other hand, in the modified example, the two tension members 2 and 2 are fixed to the receiving metal fitting 3, and the fixing intervening portions 73 and 73 are provided on both end faces of the rotating arc body main body 71.

One joint 4 insertion (pressing) operation is converted into two tension members 2 and 2 tension operations. This further improves on-site workability.

~ Concrete structures and connections ~
The concrete slab shown in the above embodiment is a typical example of a concrete structure. The present invention may be applied to other concrete structural connections. There is a box culvert as a concrete structure to be connected.

FIG. 14 is a schematic perspective view of a partial cross section according to an application example to a box culvert. A plurality of metal fittings 3 are provided at the end of the box culvert. Further, a tension member 2 is arranged between the metal fittings 3 and 3.

Box culverts are arranged so as to face each other with a predetermined width of joint spacing. The opposing metal fittings 3 and 3 and the joint 4 form a connecting mechanism 5.

Adjacent box culverts are securely and firmly connected to each other via the connecting mechanism 5.

A fixing tool 6 and an operation changing means 7 are provided in the receiving metal fitting 3 (see FIG. 5). The motion conversion means 7 converts the joint 4 insertion motion into the tension member 2 tension motion.

As a result, prestress is added to the tension material 2. If prestress is not introduced before the motion conversion, prestress is introduced into the tension member 2. If prestress is introduced in advance before the motion conversion (for example, at the time of shipment from the factory), the prestress of the tension material 2 increases.

~ Summary ~
The inventor of the present application has intended to combine a fixing tool function and a connecting function in a concrete structure. Not only the fixing tool function and the connecting function are combined, but also the motion conversion means 7 is added.

The motion conversion means 7 converts the joint 4 insertion motion into the tension member 2 tension motion. That is, when the joint 4 is inserted and fixed to the receiving metal fitting 3, the connection and the prestress addition are performed at the same time. As described above, the concrete structure connecting body of the present application is excellent in workability.

~ Application examples other than concatenation ~
In the above embodiment, the description has been made on the premise that the motion conversion means 7 operates with the connection by the joint 4, but the motion conversion means 7 operates alone (other than the connection).

By the way, in the general tensioning work of the tension material, a jig is installed in the extension direction of the tension material, the tension material is pulled and fixed in the extension direction, and prestress is introduced.

However, it may not be possible to secure sufficient construction space at sites where construction conditions are severe.

The motion conversion means 7 can convert an external force from above (direction orthogonal to the tension member) into the tension member 2 tension motion. As a result, even if the construction space cannot be secured on the side, prestress can be introduced if the construction space can be secured above.

That is, the motion conversion means 7 can independently provide a completely new tension addition structure.

1 Concrete floor slab 2 Tension material 3 Bracket (joint bracket)
4 Fittings 5 Coupling mechanism 6 Fixing tool 7 Motion conversion means 10 Coupling structure 31 Flat opening 32 Side part 33 Side part 34 Side part 35 Side part 36 Bottom part 37 Slit 38 Bolt hole 39 Tapered 41 Joint end part 42 Coupling connection part 43 Bolt 44 Tapered 71 Rotating arc body body 72 Pressing receiving part 73 Fixing interposition part 131 Inner wall curved surface part 132 Return restraining part 133 Return restraining part

Claims (9)

It is a concrete structure connecting body formed by connecting concrete structures in which tension materials are arranged.
A plurality of metal fittings provided at the end of the concrete structure and
A joint that is inserted into the opposing metal fittings and connects the concrete structures to each other.
When prestress is introduced into the tension material, a fixing means for fixing the tension material to the metal fitting and
An motion conversion means for converting an insertion motion in the joint into a tension motion in the tension material,
A concrete structural connection characterized by being provided with. The metal fitting is
A flat opening into which a part of the joint is inserted,
The facing surface portion facing the metal fitting of the adjacent concrete structure and the
A slit provided on the facing surface portion and
The facing surface portion and the end side surface portion facing the inside of the receiving metal fitting,
Have,
The inner wall of the side surface portion of the wife has a curved surface portion and has a curved surface portion.
The motion conversion means
It is a rotating arc body that can slide along the curved surface portion of the side surface portion of the metal fitting end.
Rotating arc body and
At one end of the rotating arc body body, a pressing receiving portion that receives a push due to the insertion of the joint and at the other end of the rotating arc body body, a fixing interposing portion interposed between the fixing means and the receiving metal fitting is provided. The concrete structure joint according to claim 1, wherein the concrete structure is connected. In the rotating arc body
When the push receiving part receives a push,
The rotating arc body body slides and rotates along the curved surface portion of the side surface portion of the metal fitting end,
The anchoring interposition moves in the tension direction,
The concrete structure connecting body according to claim 2, wherein prestress is applied to the tension material. The fixing interposition portion is provided on the end face of the rotating arc body main body in a curved surface shape.
The concrete structure connecting body according to claim 2 or 3, wherein the tip of the fixing means is slidable along a curved surface of the fixing interposition. The concrete structure connecting body according to any one of claims 2 to 4, wherein the pressing receiving portion extends from the rotating arc body main body to the joint side. The concrete structure connecting body according to any one of claims 2 to 5, wherein the joint and the receiving metal fitting facing each other form a cotter type joint structure. The concrete structure connecting body according to any one of claims 1 to 6, wherein the concrete structure is a concrete floor slab. The method for constructing a concrete structural connection according to claim 1.
At least two concrete structures into which prestress is introduced by the tension material are placed facing each other.
A joint is inserted into the facing metal fitting, and the force for inserting the joint is transmitted to the motion conversion means.
By moving the motion converting means in the tensioning material tension direction, the fixing means is moved in the tensioning material tensioning direction.
A method for constructing a concrete structural connection, which comprises applying prestress to the tension material. Concrete structure A tension addition structure that applies prestress to the tension material placed inside the body.
The metal fittings provided at the end of the concrete structure and
When prestress is introduced into the tension material, a fixing means for fixing the tension material to the metal fitting and
An motion conversion means for converting an external motion into the tension material tension motion,
With
The metal fittings
The flat opening capable of external operation and
The fixing surface that receives tension by the fixing means and
Have,
The inner wall of the fixing surface has a curved surface portion and has a curved surface portion.
The motion conversion means
It is a rotating arc body that can slide along the curved surface portion of the fixing surface.
Rotating arc body and
At one end of the rotating arc body body, a pressing receiving portion that receives a push by the external operation, and at the other end of the rotating arc body body, a fixing interposing portion interposed between the fixing means and the receiving metal fitting is provided. A tension-adding structure characterized by having.