JP2011080240A - Concrete structure and construction method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concrete structure and a construction method for the concrete structure achieving high effect of preventing a construction joint face of the concrete structure from being deviated. <P>SOLUTION: This concrete structure includes a construction joint concrete structural body 14 formed by jointing of successive pours of concrete for a plurality of times, a hole 4 formed by passing through the construction joint faces 21, 22 of the construction joint concrete structural body 14 from an outer face of the construction joint concrete structural body 14, a reinforcing body 5 provided in the hole 4 to pass through the construction joint faces 21, 22, and a filler 6 filled into the hole 4 including the reinforcing body 5 therein. The concrete of the construction joint concrete structural body 14 is prestressed concrete formed by applying compressive force by the reinforcing body 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a concrete structure having a high effect of preventing displacement of a joint surface of a concrete structure and a method for constructing the concrete structure.

  A bridge pier is known as a concrete structure having a structure in which a reinforcing member is inserted into a hole provided downward from the upper end surface and a filler is injected and cured between the hole and the reinforcing member (for example, a patent) Reference 1 etc.).

JP 2007-247302 A

However, the concrete of the concrete structure described above is not formed into prestressed concrete. Therefore, the frictional force between the joint surfaces of the concrete structure is weak, and there is a problem that the joint surfaces of the concrete structure are easily displaced when an earthquake force is applied to the concrete structure.
The present invention provides a concrete structure and a concrete structure construction method that have a high effect of preventing the displacement of the joint surface of the concrete structure.

According to the present invention, the jointed concrete structure formed by piercing the concrete into a plurality of times and the joint surface of the jointed concrete structure provided from the outer surface of the jointed concrete structure are provided. And a reinforcing body installed in the hole so as to penetrate the joint surface, and a filler filled in the hole in which the reinforcing body is installed. Because it is formed on prestressed concrete that has been subjected to compressive force by the body, the introduction of prestress increases the frictional force between the joining surfaces, and the concrete structure is highly effective in preventing displacement of the joining surface of the concrete structure. It becomes.
Since the hole is a bottomed hole opened at the upper end surface of the jointed concrete structure, the hole can be easily formed. Moreover, a hole and a reinforcing material can be installed in the state which is perpendicular | vertical or near perpendicular | vertical, and it becomes a concrete structure where the shear strength, bending strength, and toughness with respect to an earthquake force improve more.
Since the reinforcing body is an unbonded steel material, adhesion between the filler and the unbonded steel material is eliminated, and a tensile operation when applying a tension to the unbonded steel material can be facilitated. Moreover, since there is no adhesion part of unbonded steel material and a filler, when unbonded steel material is pulled and tensioned, the hardened filler becomes difficult to destroy and it becomes a high-quality concrete structure.
The method for constructing a concrete structure according to the present invention is such that, for a jointed concrete structure in which concrete is handed over in multiple times, the joint surface of the jointed concrete structure is penetrated from the outer surface of the jointed concrete structure. Forming a hole in the hole, installing a reinforcing body in the hole so as to penetrate the joint surface, filling the hole in which the reinforcing body is installed, filling the filler and solidifying the filler, and then tensioning the reinforcing body Because the compressive force was applied to the concrete of the jointed concrete structure through the introduction of prestress, the frictional force between the jointed surfaces increased, and a concrete structure with a high effect of preventing displacement of the jointed surface of the concrete structure was constructed. it can.
Tension force is introduced into the reinforcement body in advance, this reinforcement body is installed in the hole so as to penetrate the joint surface, and the filler is filled in the hole in which the reinforcement body is installed. Since the compression force is applied to the concrete of the jointed concrete structure by releasing the force, the construction is simple and the tension management at the construction site can be made unnecessary.

Sectional drawing which shows an pier (embodiment 1). Sectional drawing which shows the pier using unbonded steel materials (embodiment 2). Sectional drawing which shows the pier using a steel pipe (embodiment 4). Sectional drawing which shows the pier using a steel pipe (Embodiment 5). The figure which shows the construction method of the pier using a steel pipe (embodiment 4). The figure which shows the construction method of the pier using a steel pipe (embodiment 5). The figure which shows the construction method of the pier at the time of using a steel pipe (embodiment 6).

Embodiment 1
As shown in FIG. 1, the pier 1 as a concrete structure is formed by a foundation portion 2, a pier body 3, a hole 4, a reinforcing body 5, a filler 6, and a fixing member 56.

The foundation part 2 is a footing foundation, for example, and is provided on the ground 10.
The pier main body 3 is formed on the foundation portion 2 by piercing the concrete into a plurality of times. The height of the pier body 3 is, for example, 2 to 3 m or more.
The foundation 2 and the pier body 3 constitute a joint concrete structure 14 formed by jointing the concrete into a plurality of times. The joint concrete structure 14 is a reinforced concrete structure or an unreinforced concrete structure. The concrete structure has a horizontal cross-sectional shape, for example, a circular shape, a rectangular shape, or a polygonal shape.
The hole 4 is a bottomed hole opened on the outer surface of the joint concrete structure 14. For example, the hole 4 is formed so as to extend from the upper end surface 7 of the joint concrete structure 14 to the base portion 2, and one or more joint surfaces 21 formed in the pier body 3 and the upper surface of the base portion 2. 8 is formed by a bottomed hole having a bottom end and an opening at the other end provided so as to penetrate the joint surface 22 that is a boundary between the pier body 3 and the pier body 3.
The reinforcing body 5 is installed in the hole 4 so as to penetrate all the joining surfaces 21; 21, 22; As the reinforcing body 5, a tendon is used. As the tension material, a PC steel material, a tension material formed of carbon fiber, or the like is used. As the PC steel material, for example, a PC steel rod (high strength steel having a diameter of 10 mm or more), a PC steel wire (a combination of PC steel wires which are high strength steel having a diameter of 8 mm or less), and the like are used.
The fixing member 56 includes a first end side fixing member 57 attached to one end portion of the reinforcing body 5 and a second end side fixing member 58 attached to the other end portion of the reinforcing body 5. The one end-side fixing member 57 is formed by a projecting body that projects from the peripheral surface of one end of the reinforcing body 5. The protruding body is formed by a nut member that is screwed to a screw portion (not shown) formed on the peripheral surface of one end portion of the reinforcing body 5 and fixed to the one end portion of the reinforcing body 5, for example. The other end side fixing member 58 passes through a plate 58a installed on the upper end surface 7 of the joint concrete structure 14 so as to cover the other end opening 41 of the hole 4 and a through hole 58b formed in the center of the plate 58a. It is formed by a nut member 58 c that is screwed to a screw portion (not shown) formed on the peripheral surface of the other end portion of the reinforcing body 5 and is fixed to one end portion of the reinforcing body 5.
The filler 6 is filled between the reinforcing body 5 installed in the hole 4 and the inner wall 9 of the hole 4 so as to penetrate the joint surfaces 21; 21, 22; 22 of the joint concrete structure 14. . As the filler 6, mortar or cement milk having high fluidity and no shrinkage is used.

  Filling the hole 4 in which the reinforcing body 5 is installed with the filler 6, passing the through hole 58b of the plate 58a to the other end of the reinforcing body 5 protruding outside the hole 4, and screwing the nut member 58c; By tightening the nut member 58c to the plate 58a in a state where the other end of the reinforcing body 5 is pulled by a tension device (not shown) after the filler 6 is solidified, the concrete of the joint concrete structure 14 is subjected to a compressive force. As a result, it is formed into prestressed concrete in which the frictional force between the joining surfaces 21; 21, 22;

A specific description will be given based on FIG.
The pier main body 3 is formed by, for example, dividing concrete into three parts. First, after the concrete is cast on the upper surface 8 of the foundation portion 2 to form the first concrete layer 11 having a predetermined height, the second concrete layer 12 is similarly formed on the first concrete layer 11 after being left for one day or more. Form. Thereafter, similarly, the third concrete layer 13 is formed on the second concrete layer 12. That is, the joining surfaces 21; 21, 22; 22 extending in the horizontal direction are provided at three positions with a predetermined interval in the vertical direction. The place where the holes 4 are formed is determined according to the construction conditions, and the number of the holes 4 may be determined based on the design. For example, the hole 4 extends vertically downward from the upper end surface 7 of the pier body 3 and is formed so as to penetrate the three joint surfaces 21; 21, 22;
Then, the reinforcing body 5 to which the one-end-side fixing member 57 is attached is inserted into the hole 4 from one end side, and one end of the reinforcing body 5 is brought into contact with the hole bottom 20 of the hole 4 and the other end of the reinforcing body 5 is connected to the hole 4. The filler 6 is filled into the hole 4 in which the reinforcing body 5 is inserted in a state of protruding from the other end opening 41 to the outside of the hole 4. The filler 6 is filled between the inner wall 9 of the hole 4 and the outer peripheral surface of the reinforcing member 5 and the one end side fixing member 57 installed in the hole 4. That is, the filler 6 is filled in the entire hole 4 in which the reinforcing body 5 to which the one end side fixing member 57 is attached is inserted. The filling of the filler 6 into the hole 4 may be performed using the filling device 42 described in the fourth embodiment. Then, the through hole 58b of the plate 58a is passed through the other end of the reinforcing body 5 protruding outside the hole 4, and the nut member 58c is screwed. After the filler 6 is solidified, a tension device (not shown) is attached to the other end of the reinforcing body 5 and the nut member 58c is fastened to the plate 58a in a state where the reinforcing body 5 is pulled. As a result, the filler 6 is compressed by the one-end-side fixing member 57 attached to one end of the reinforcing body 5, and this compressive force is applied to the jointed concrete structure via the adhesion between the filler 6 and the inner wall 9 of the hole 4. It is transmitted to the concrete of the body 14. Therefore, the joint concrete structure 14 is formed into prestressed concrete in which the compressive force is applied and the frictional force between the joint surfaces 21; 21, 22; 22 is increased.

According to the pier 1 of the first embodiment, the introduction of pre-stress increases the frictional force between the joining surfaces 21; 21, 22; 22 of the joining concrete structure 14, and prevents displacement of the joining surface of the concrete structure. The pier 1 is highly effective.
Since the hole 4 is formed by the bottomed hole opened in the upper end surface 7 of the joint concrete structure 14, the formation of the hole 4 is facilitated, and the hole 4 and the reinforcing body 5 can be installed in a vertical or nearly vertical state. As a result, the pier 1 is further improved in shear strength, bending strength, and toughness against seismic force. In addition, the filling material 6 can be easily filled in the entire hole 4 in which the reinforcing body 5 to which the one-end-side fixing member 57 is attached is inserted, and workability can be improved.
In addition, since the filling material is filled in the entire hole 4 in which the reinforcing body 5 to which the one-end-side fixing member 57 is attached is inserted, the fixing of the reinforcing body 5 is stabilized, and when the seismic force is applied, As compared with the case where there is a space, the effect of preventing the displacement of the reinforcing body 5 is improved.

  If a spacer (not shown) similar to the spacer / hanging portion 23 to be described later is attached to the outer peripheral surface of the reinforcing body 5, the central axis and the hole 4 of the reinforcing body 5 when the reinforcing body 5 is installed in the hole 4. The center axis of the reinforcing member 5 can be made coincident with each other, and the reinforcing body 5 can be prevented from being inclined and installed in the hole 4, which is preferable. If spacers outside the figure are provided at least on the outer peripheral surface of one end of the reinforcing member 5 and the outer peripheral surface of the other end of the reinforcing member 5, the reinforcing member 5 is inclined and installed in the hole 4. This is preferable because it can be effectively prevented.

Embodiment 2
As shown in FIG. 2, an unbonded steel material 69 may be used as the PC steel material. As the unbonded steel material 69, an unbonded steel rod, an unbonded steel strand or the like is used.
The unbonded steel material 69 is a steel material in which the periphery of the steel material for preventing the adhesion between the steel material and the concrete is coated, and includes a PC bar 70 and a coating part 75. The covering portion 75 is formed by a coating material applied to the peripheral surface 76 of the PC rod 70 or a covering material coated on the peripheral surface 76 of the PC rod 70. As the coating material, for example, an asphalt polymer is used. As the covering material, a rust preventive material, polypropylene, polyethylene sheath and the like are used. The covering material is wound around the peripheral surface of the PC bar 70.

  According to the second embodiment, in addition to the effects of the first embodiment, the following effects can be obtained. When the unbonded steel material 69 is used, the PC rod 70 and the filler 6 are cut off by the covering portion 75, so that the intermediate portion of the PC rod 70 does not adhere to the filler 6, and the PC is used by a tension device (not shown). Since the rod body 70 can be easily pulled, tension can be easily applied to the PC rod body 70. Moreover, since adhesion between the hardened filler 6 and the PC bar 70 can be prevented, when the PC bar 70 is pulled and tensioned, the hardened filler 6 is less likely to be broken, and the quality pier 1 is obtained. . Moreover, by making the unbonded steel material 69 unbonded, a prestressed concrete sheath and grout work can be omitted, and the construction can be simplified.

Embodiment 3
Moreover, you may introduce tension | tensile_strength into PC steel materials previously.
A tension force is introduced into the reinforcing body 5 in advance, the reinforcing body 5 is installed in the hole 4 so as to penetrate the joint surfaces 21; 21, 22; 22, and a filler is provided in the hole 4 in which the reinforcing body 5 is installed. The compressive force is applied to the concrete of the joint concrete structure 14 by releasing the tension force after the filler 6 is solidified after the filler 6 is filled.
According to this, since the introduction of the prestress force only releases the tension force at the construction site, the construction is simple and the tension management at the construction site can be made unnecessary.

Embodiment 4
As shown in FIG. 3, a tubular body is used as the reinforcing body 5. When the steel pipe 15 is used as the pipe body, no prestress is introduced into the jointed concrete structure 14. As the steel pipe 15, a steel pipe 15 having a full length that is smaller than the diameter of the hole 4 and shorter than the length of the hole 4 is used. On the outer peripheral surface of the steel pipe 15, when the steel pipe 15 is installed in the hole 4, a spacer / hanging portion 23 is provided by welding so that the central axis of the steel pipe 15 and the central axis of the hole coincide with each other. If this spacer / hanging portion 23 is provided at least on the outer peripheral surface of one end of the steel pipe 15 and the outer peripheral surface of the other end of the steel pipe 15, it is effective that the steel pipe 15 is inclined and installed in the hole 4. Therefore, it can be prevented.

  In the method of constructing the pier 1 of the fourth embodiment, after the joint concrete structure 14 is formed, a steel pipe support 25 is provided on the upper end surface 7 of the pier body 3 as shown in FIG. The steel pipe 15 is hung in the hole 4 by attaching the hanger 26 hung from the base 25 to the spacer / hanging portion 23 of the steel pipe 15 installed in the hole 4. That is, the lower end 16 of the steel pipe 15 is maintained in a state separated from the hole bottom 20. Then, the filler 6 is filled into the hole 4 using the filling device 42. The filling device 42 includes an injection tube 24, a first connection tube 17, an on-off valve device 27, a second connection tube 18, a pump 28, a third connection tube 19, and a filler storage unit 29.

  A filling method using the filling device 42 will be described. One end of the injection tube 24 having flexibility is inserted into the steel tube 15, and the lower end 16 of the injection tube 24 is kept away from the hole bottom 20, and the other end of the injection tube 24 is one end opening of the hole 4. It is in a state of projecting upward from 41. One end of the first connection pipe 17 is detachably connected to the other end of the injection pipe 24, and the other end of the first connection pipe 17 is connected to the outlet of the on-off valve device 27. One end of the second connection pipe 18 is connected to the inlet of the on-off valve device 27, and the other end of the second connection pipe 18 is connected to the discharge port of the pump 28. One end of the third connection pipe 19 is connected to the suction port of the pump 28, and the other end of the third connection pipe 19 is connected to the outlet of the filler storage unit 29. By opening the on-off valve of the on-off valve device 27 and driving the pump 28, the filler 6 is transferred from the filler storage portion 29 via the third; 2; 1 connecting pipe 19; 18; 17 and the injection pipe 24. It fills between the outer peripheral surface of the steel pipe 15 and the inner wall 9 of the hole 4 from the lower end opening 30 of the injection pipe 24. When the filler 6 reaches the upper end surface 7 of the pier 3, as shown in FIG. 5B, one end of the first connection pipe 17 is removed from the injection pipe 24, and protrudes upward from the one end opening 41 of the hole 4. The other end of the injection tube 24 is cut. Thus, the pier 1 in which the filler 6 is filled between the inner wall 9 of the hole 4 and the outer peripheral surface of the steel pipe 15 and in the pipe of the steel pipe 15 is completed (see FIG. 3; FIG. 5C).

According to the pier 1 of the fourth embodiment, since the hole 4 is formed by the bottomed hole opened in the upper end surface 7 of the joint concrete structure 14, the formation of the hole 4 is facilitated, and the hole 4 and the reinforcing body 5 are formed. Can be installed in a vertical or nearly vertical state, so that the pier 1 is further improved in shear strength, bending strength, and toughness against seismic force.
Furthermore, it becomes possible to quickly and easily fill the entire inside of the hole 4 via the inside of the steel pipe 15 and improve workability.

Embodiment 5
As shown in FIG. 4, a pier 1 using a steel pipe 35 having a pipe filling material discharge port 31 on a peripheral wall on the lower end side as a pipe body as the reinforcing body 5 was used. The steel pipe 35 is the same as the steel pipe 15 except that the steel pipe 35 includes the filler discharge port 31. For example, as shown in FIG. 6C, the filler discharge port 31 is formed by removing a part of the peripheral wall at the lower end portion of the steel pipe 35.
As shown in FIG. 6A, first, the steel pier 35 is inserted into the hole 4 from the upper end surface 7 of the pier 1 and the lower end 36 of the steel pipe 35 is connected to the bottom 20 of the pier 1 according to the fifth embodiment. Thrust into. Then, by filling the hole 4 with the filler 6 using the above-described filling device 42, the filler 6 passes through the pipe of the steel pipe 35 and the filler discharge port 31, and the inner wall 9 of the hole 4 and the steel pipe 35. It is filled between the outer peripheral surfaces. Therefore, the bridge pier 1 in which the filler is filled in the pipe of the steel pipe 15 and between the inner wall 9 of the hole 4 and the outer peripheral surface of the steel pipe 35 is completed (see FIG. 3; FIG. 6B).

According to the fifth embodiment, in addition to the effects of the fourth embodiment, the lifting tool 26 is not necessary, and thus workability is improved.
If the same spacer as described above is provided on the outer peripheral surface of the steel pipe 35, when the steel pipe 35 is installed in the hole 4, the central axis of the steel pipe 35 and the central axis of the hole 4 can coincide with each other. It is preferable that 35 is inclined and can be effectively prevented from being installed in the hole 4.

  The filler discharge port 31 may be formed in the peripheral wall at the lower end of the steel pipe 35 by a through-hole penetrating in and out of the pipe. Further, when the filler discharge port 31 is provided at the lower end portion of the steel pipe 35 with a protruding portion protruding from the lower end of the steel pipe 35, the lower end of the protruding portion is projected to the hole bottom 20 as the lower end 36 of the steel pipe 35. It is formed by a space formed between the lower end 36 (lower end of the projecting portion) 36 and the hole bottom 20.

Embodiment 6
As described above, in the case of using the steel pipe 15; 35, a short steel pipe 15a or a steel rod outside the figure may be added as shown in FIG.
According to the sixth embodiment, in addition to the effects of the fourth embodiment, the operation of inserting the steel pipe 15a and a steel rod outside the figure into the hole 4 is facilitated.

  A steel pipe having the same length as the length of the hole 4 may be used as the reinforcing body 5. When the steel pipe is used, the lower end (one end) 36 of the steel pipe is abutted against the hole bottom 20 and the steel pipe is installed in the hole 4. And the filler 6 should just be filled between the reinforcement body 5 installed in the hole 4, and the inner wall 9 of the hole 4, and the inside of a steel pipe.

  The present invention can be applied to a concrete structure constructed by a plurality of times of concrete joining, and can be applied to a concrete structure such as an abutment or a retaining wall in addition to a bridge pier.

1 concrete structures (piers), 4 holes, 5 reinforcements, 6 fillers,
7 upper end surface, 14 jointed concrete structure, 21; 22 joint surface,
69 Unbonded steel.

Claims (5)

  A cast-in-place concrete structure formed by piercing concrete in multiple times, a hole provided so as to penetrate from the outer surface of the joint-concrete structure to the joint surface of the joint-concrete structure, and piercing Reinforcing body installed in the hole so as to penetrate the surface and filler filled in the hole in which the reinforcing body is installed. The concrete of the jointed concrete structure is subjected to compressive force by the reinforcing body. A concrete structure characterized by being formed into prestressed concrete.   The concrete structure according to claim 1, wherein the hole is a bottomed hole opened at an upper end surface of the joint concrete structure.   The concrete structure according to claim 1 or 2, wherein the reinforcing body is an unbonded steel material.   Form the jointed concrete structure by piercing the concrete in multiple times, forming holes in the jointed concrete structure from the outer surface to penetrate the jointed surface of the jointed concrete structure, A reinforcing body is installed in the hole so as to penetrate through the hole, and a filler is filled in the hole in which the reinforcing body is installed, and the reinforcing body is tensioned after the filler is solidified. A construction method of a concrete structure characterized by applying a compressive force.   Tension force is introduced into the reinforcement body in advance, this reinforcement body is installed in the hole so as to penetrate the joint surface, and the filler is filled in the hole in which the reinforcement body is installed. The method for constructing a concrete structure according to claim 4, wherein a compressive force is applied to the concrete of the jointed concrete structure by releasing the force.

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