JP2005097995A - Precast prestressed concrete member and joining method for precast prestressed concrete member and the other member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a precast PC member, a method of manufacturing the precast PC member, and a method of jointing these precast PC members capable of introducing prestress also in the precast PC member and the other member. <P>SOLUTION: In this precast PC member 3, the intermediate part of a PC steel material is buried in the cross section of the precast PC member and the end part of the PC steel material is fixed to a precast PC member body for adding precast thereto. The tip side of a pre-tensed hollow PC steel bar 1 in a prestress introducing device 4 for connection and concrete is buried, separately from the PC member, in the precast PC member 3 on on end part or both end parts thereof supporting mainly a tensile stress. A prestress force is held in the hollow PC steel bar 1, the base end of the device 4 is disposed to be extended from the end part of the precast PC member 3 to the outside. By that portion 10, a joining part on which the prestress force of the hollow PC steel bar 1 is held is formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a precast PC member manufactured by a pretension method and a method of joining the precast PC member and another member.

  In general, PC piles, PC utility poles, diagonal members of concrete truss bridges and the like used as beam members or pile foundations of structures are characterized by being elongated as precast PC members.

  In the case of manufacturing such a PC member, it is suitable for a manufacturing method in which molding is performed by rotating a mold into which concrete has been put and compacting by centrifugal force. Further, as a method for making such a member into a prestressed concrete structure, Japanese Patent Laid-Open No. 9-49230 and the like are published.

  Such a PC member manufacturing method is, in principle, a method using an apparatus as shown in FIG. 14, and will be described with reference to FIG. PC steel material 35 is locked to both end plates 33, 34 provided on the inner side, and the jack 36 is shortened from the extended state while the jack reaction force is applied to the tension end end outer frame 32, and the PC steel material 35 is tensioned. Next, the concrete 2 is put into the side frame 30. After curing, after the concrete 2 reaches a predetermined strength, the jack 36 is released and prestress is introduced into the concrete 2, for example, PC pile A precast PC member 40 such as the above is manufactured.

  A precast PC member 40 made of a PC pile manufactured in this way is used, for example, as a tensile diagonal member 38 of a concrete truss bridge 37 as shown in FIG. When connecting the piles 40) 38, as shown in FIG. 15 (b), a steel flange 41 is attached in advance to the end of the PC pile 40 and bolted to the grading member 39 made of grading block concrete. It is common to do.

  The characteristics of the conventional pre-tension type PC members are as follows: After placing concrete in a factory, etc., after the concrete exhibits the required strength, immediately release the jack at the end of the member to release the tension of the PC steel And, it is characterized in that prestress is introduced into the concrete and the tensile strength of the member is maximized.

  As described above, the conventional precast PC member has been shown to increase the tensile strength of the precast PC member by using the PC steel material. However, other members are joined by the PC steel material, and other concrete members can be used. However, there is no suggestion or disclosure about the point where prestress can be introduced.

  It is also known to use a precast member as a diagonal member of a truss structure (see, for example, Patent Document 2).

By the way, in a joining structure in which a precast PC member is joined to a cast-in-place concrete member or a precast member, when a bending moment is generated in the precast member, joining by a post tension method is generally performed, but drying shrinkage, etc. Therefore, when cracking occurs in the precast member before introducing prestress, or when trying to introduce prestress necessary for the joint, it is necessary to place unnecessary PC steel in the precast member other than the end of the member It becomes uneconomical. Also, if the bending moment is reversed at both ends of the precast member and the tensile stress is reversed at the upper and lower edges, the prestress required at both ends of the member must be applied by the axial force in the case of a thin or short member that cannot be placed in the PC steel. There is a need to arrange a large amount of PC steel.
JP-A-9-49230 JP 2000-336769 A

  The precast PC member 40 has the following problems (1) to (4).

(1) It becomes the precast PC member 40 which is not equipped with the means which can join the concrete member joined to the edge part of the precast PC member 40, and if a joining means is attached separately, a structure will become complicated and cost will become high.

(2) Since all the PC steel materials must be placed in tension by applying a reaction force to the mold, the PC steel materials to be used are limited, and the degree of freedom of the PC steel materials is low.

(3) In addition to the above (1), since the PC member 40 itself is structurally not provided with a part for attaching another concrete member (for example, the grade member 39), the other concrete member As for the joining, there is only a method in which a flange 41 is provided on the PC member 40 and integrated by bolts and nuts 42.

(4) When the PC member 40 made of PC pile and other concrete are to be joined, it is necessary to temporarily assemble the PC pile 40 at a manufacturing factory of the PC pile 40, and place and manufacture other concrete. It was complicated.

  The present invention takes advantage of the point of increasing the tensile strength of the precast PC member itself by the solid PC steel material, and the precast PC member itself and other members by the prestress introduction device for joining PC steel or joining and concrete. It is possible to join, and prestress can be introduced to other concrete members, and the pre-stressed PC steel material or pre-stress introduction device for joining and concrete is efficiently arranged on the side bearing the tensile force in the precast PC member. An object of the present invention is to provide an economical precast PC member and a method for joining the member and another member.

  In order to solve the above problems, the following precast PC member, a method for manufacturing the member, and a method for manufacturing the same are provided.

  In the precast PC member according to claim 1, an intermediate portion of the PC steel material is embedded in the cross section of the precast PC member, and an end portion of the PC steel material is fixed to the precast PC member main body and is preliminarily attached to the precast PC member main body. In the precast PC member 3 to which stress is applied, separately from the PC steel material, the precast PC member 3 has one end portion or both end portions of the PC steel material 1 for joining in a cross section on the side mainly bearing a tensile stress. The distal end side is embedded and the base end portion of the joining PC steel material 1 is disposed so as to extend outward from the main body end portion of the precast PC member 3, and outside the main body end portion 9 of the precast PC member 3. The junction part is comprised by the part 10 arrange | positioned so that it may extend, It is characterized by the above-mentioned.

  The precast PC member according to claim 2, wherein an intermediate portion of the strained PC steel material is embedded in the cross section of the precast PC member, and an end portion of the PC steel material is fixed to the precast PC member main body to be precast PC member. In the precast PC member 3 in which prestress is applied to the main body, it is pre-tensioned in the cross section on the side mainly bearing the tensile stress at one or both ends of the precast PC member 3 separately from the PC steel material. The tip side of the hollow PC steel rod 1 in the prestress introduction device 4 for joining and concrete is embedded and arranged, and in the device 4, a reaction force PC steel rod 25 (6, 24) is inserted into the hollow PC steel rod 1, While letting the reaction force PC steel rod 25 take the reaction force, a tension force is introduced into the hollow PC steel rod 1 in advance and the tension force is released to reduce the force. A support cylinder 7 provided with a stopper 19 that is configured to be applied with a prestressing force against cleats and screwed into a base end portion of the hollow PC steel rod 1, and a distal end portion of the hollow PC steel rod 1 The prestressing force of the hollow PC steel bar 1 is held by the end holder 8 screwed to the end holder 8, and the base end portion of the device 4 extends outward from the main body end portion of the precast PC member 3. The joint portion in which the prestressing force of the hollow PC steel rod 1 is maintained is constituted by the portion 10 disposed so as to extend outward from the main body end portion 9 of the precast PC member 3. It is characterized by that.

  According to a third aspect of the present invention, in the precast PC member according to the second aspect, an internal thread hole 26 is provided on the inner side of the distal end portion of the hollow PC steel rod 1, and an end holder made of an external thread member is formed in the internal thread hole 26. 8, a male screw portion 14 is provided on the outer side of the distal end portion of the hollow PC steel rod 1, and an anchor member 27 is detachably engaged with the male screw portion 14.

  Moreover, in invention of Claim 4, in the precast PC member in any one of Claims 1-3, PC steel material 1 for joining arrange | positioned at the one end part and the other end part of the precast PC member 3, or joining joint The concrete prestress introduction device 4 is characterized in that the one end and the other end of the precast PC member 3 are arranged on the same side or different sides in the member thickness direction of the precast PC member 3.

  In addition, the invention according to claim 5 extends the precast PC member 3 according to any one of claims 1 to 4 to the outside of the main body of the precast PC member after being arranged at a predetermined position so as to build a concrete structure. Utilizing the portion 10, prestress is introduced into both the precast PC member 3 and the other concrete member, and a concrete structure composed of the precast PC member 3 and the other concrete member is integrated. This is a method of joining the precast PC member and the other member.

The effects of the present invention are as follows.
(1) The precast PC member is prestressed by pre-tension, and by placing the pre-stress introduction device for joining PC steel or joining / concrete only in the vicinity of both ends of the precast member, it is necessary for the end of the member. Pre-stress can be applied, and pre-stressing up to pre-cast members can prevent cracks caused by drying shrinkage, etc. It becomes possible. Moreover, the pre-stress introduction device for joining PC steel or joining / concrete has an effect of compensating pre-stress due to pre-tension in the pre-stress effective transmission length section given by pre-tension at the end of the member. In addition, it is possible to arrange at different positions in order to cancel the tensile stress at both ends of the member generated in different directions up and down generated by different bending moment directions. The precast PC member provided with the prestress introduction device can be used, and particularly in the case of the present invention, the precast PC member is disposed in the cross section mainly bearing the tensile stress at one end portion or both end portions of the precast PC member. It can be set as a precast PC member.
(2) The unit of the prestressing device for joining and concrete, which has been prestressed in the factory for manufacturing the prestressing device for joining and concrete, is a self-contained unit (a steel rod inside and outside the device body). The tension force and the compression force can be balanced and the release operation can be performed), and it is not necessary to take the reaction force of the prestress force in the side mold. Moreover, since the prestress introduction apparatus for joining and concrete should just be arrange | positioned only at the edge part of a precast PC member, it can be easily arrange | positioned and used also for a long precast PC member. Moreover, since prestress is given to the precast PC member over the entire length by the PC steel material, there is no fear that the main body portion is damaged during the transport of the precast PC member.
(3) Since prestress can be introduced for the connection portion between the precast PC member and the other concrete member, the connection can be made more robustly than when connecting with a reinforcing bar or a bolt.
(4) Although the end of the prestressing device for joining and concrete extending from the precast PC member body can extend the connection length from the end, depending on the application, it can be extended only at both ends or only one end of the precast PC member. Can be used for various purposes.
(5) When joining a precast PC member and another member, the concrete placement of the other member can be performed with high precision by performing on-site.
(6) Prestressing device for joining and concrete in which tension is introduced into a small number of hollow PC steel bars or the end of the joining PC steel material is placed in the mold, and concrete or mortar is placed in the mold. It is a precast PC member that can be easily manufactured at low cost by filling and rotating the mold as necessary to cure concrete or mortar.
(7) The structure of the precast PC member of the present invention is a simple structure.
(8) Since the anchor member on the front end side (end holder side) in the prestress introduction device for joining and concrete is detachable, when manufacturing a precast PC member, the outer diameter of the anchor member is smaller than that of the anchor member. What is necessary is just to provide a through-hole, that is, a small through-hole for inserting the hollow PC steel rod into the mold, and even if the anchor member on the tip side is removed, the tension introduced into the hollow PC steel rod Can hold power. Similarly, in the case of the PC steel material for joining, a small through hole for inserting the same may be provided in the mold or the like.

Next, the present invention will be described in detail based on the illustrated embodiment.
1 to 4 show a precast PC member and a structure thereof according to a first embodiment of the present invention. FIG. 1 (a) is a side view showing the whole, and FIG. 1 (b) is an enlarged part. Fig. 2 (a) is an enlarged vertical side view showing the left end (on the different diameter holder side) of Fig. 1b, and Fig. 3 (a) is a cross-sectional view taken along line AA of Fig. 2 (b). 3 (b) is a cross-sectional view taken along the line BB of FIG. 2b, and FIG. 4 is a partially longitudinal side view showing the right end portion (end holder side) of the concrete prestress introduction device and the different diameter holder side in an enlarged manner. It is. FIG. 5 is a longitudinal side view showing an embodiment of the manufacturing method of the present invention when the precast PC member 3 made of PC pile is subjected to centrifugal force molding.

  Hereinafter, an embodiment of a method for producing a precast PC member 3 made of PC pile will be described in detail with reference to FIGS. In addition, as the precast PC part 3 in this invention, it can be used for general concrete members other than PC pile.

  On a yard near a precast PC member manufacturing apparatus such as a PC pile, a prestress introduction apparatus 4 for joining and concrete used in the present invention (in the case of illustration, a unit that can be freely disassembled and assembled, its details The structure will be described later.) Or two steel caps 12, 13 provided with a PC steel material through hole 11 for inserting a PC steel material and a PC steel material through hole 35a for inserting a PC steel material 35 are provided. Prepare and place them in parallel at intervals.

  In the present invention, particularly in order to economically manufacture the precast PC member 3, the arrangement of the PC steel through holes 11 in the two steel caps 12 and 13 is used in the place where the precast PC member 3 is used. If it is arranged only on the side where bending acts and mainly the tensile stress needs to be canceled, it becomes a low-cost precast PC member 3, so that one side in the radial direction (one side in the thickness direction of the member) ) Or at one end and the other end of the precast PC member 3 so that they can be arranged on different sides in the member thickness direction of the precast PC member 3 around the member center axis. 12 and 13 are provided.

  The steel caps 12 and 13 are steel caps having a cross-sectional groove shape, and one steel cap 12 is provided with a through hole for inserting the mortar injection pipe 51 at the center of the groove bottom plate, Further, the groove bottom plates 12a and 13a of the steel caps 12 and 13 have a plurality (in the case of illustration) spaced circumferentially on one side (lower side in the case of illustration) around the lateral center axis in the left-right direction. Two PC steel material insertion through holes 11 are provided, and the PC steel material insertion through holes 35a having a diameter smaller than that of the PC steel material insertion through holes 11 are substantially between the through holes 11 in the circumferential direction. They are provided at equiangular intervals.

  Next, the pre-stress introduction device 4 for joining and concrete and the PC steel material 35 are inserted into the through holes 11 and 35a for inserting the PC steel material, and are attached here. The structure of the prestress introduction device 4 for cum concrete will be described with reference to FIGS. In particular, FIG. 4 shows the structure of both ends of the prestress introduction device 4 for joining and concrete, and the intermediate part has a constant shape and no change, and will be described with reference to FIG.

  This prestress introduction device 4 for joining and concrete is a form of a prestress force introduction device for concrete using a hollow PC steel rod 1 and is arranged in the hollow PC steel rod 1 after prestressing is introduced into concrete. The reaction force PC steel rod 6 is of a non-pull method (not pulled out) and remains in the hollow PC steel rod 1 as it is (placed). Compared to the case where the reaction force PC steel rod 6 is pulled out. This is an advantageous form in terms of cost.

  The male threaded portion 15 in the hollow PC steel rod 1 having a male threaded portion 14 on the outer side of the base end portion (rear end portion) outside the male threaded portion 14 on the outer side of the longitudinal end portion of the steel hollow PC steel rod body 1a, A bearing comprising two different diameter female screw holes, a small diameter female screw hole 16 at the distal end and a large diameter female screw hole 17 at the proximal end, and a different diameter holder having a rotating tool engaging outer surface 18 such as a hexagon. A female screw hole 16 at the tip of the cylinder 7 is screwed together.

  A front male threaded portion 20 of a stopper 19 made of a steel cylindrical annular locking piece is screwed into a female threaded hole 17 at the proximal end portion of the support tube 7, and the proximal end portion (rear end portion) of the stopper 19 is outside. Is formed with an outer surface 21 for engaging a rotating tool such as a hexagon, and a front end portion of the stopper 19 is disposed inside the support cylinder 7 and is behind a press locking piece 23 having a concave portion 22 at a tip end portion. One end side is inserted into the hollow PC steel rod 1 and the other end protrudes from the rear end portion of the hollow PC steel rod 1 in the recess 22 at the front end portion of the press locking piece 23. The rear end portion of the short removal reaction force PC steel rod 24 arranged in this manner is fitted, and the entire front end portion of the removal reaction force PC steel rod 24 is accommodated in the hollow PC steel rod 1. The rear end portion of the non-pulling reaction force PC steel rod 6 arranged in the above state is brought into contact. In this embodiment, the removal reaction force PC steel rod 24 and the non-pulling reaction force PC steel rod 6 constitute a pushing reaction force PC steel rod 25.

  An end holder 8 made of a male screw member is screwed into the female screw hole 26 inside the distal end portion of the hollow PC steel rod 1, and an anchor member 27 made of a nut or the like is fitted to the male screw portion 14 outside the distal end portion of the hollow PC steel rod 1. Are detachably screwed and fixed, and the front end portion of the non-pull reaction force PC steel rod 6 is in contact with the rear end surface of the end holder 8. Further, an anchor member 28 made of a nut or the like is screwed into an intermediate portion of the male screw portion 15 on the rear end side of the hollow PC steel rod 1.

  When the tension force is introduced into the hollow PC steel bar 1 in the prestress introducing device 4 for joining and concrete as described above, the anchor material 28 is supported on the frame-shaped frame in a simple manner without illustration. As described above, the prestress introduction device 4 for joining and concrete is disposed on the frame-shaped frame, and is engaged with the tip of the movable piston of the jack by using a hydraulic jack mounted on the frame-shaped frame. The pressing locking piece 23 is pressed so as to move toward the hollow PC steel rod 1 by a pushing steel rod inserted into the central hollow portion of the stopper 19, and the removal reaction force PC steel rod 24 and the non-pull (stationary ) After introducing the compression force so that the reaction force PC steel rod 6 is pushed into the hollow PC steel rod 1, the support cylinder 7 or the stopper 19 which is free in that state is The stopper 19 is rotated forward in a direction approaching the pressing locking piece 23 (right direction in FIG. 4), the front end portion of the stopper 19 is pushed into engagement with the locking piece 23, and the frame When separated from the shaped frame, tension can be introduced into the hollow PC steel rod 1. The tension force of the hollow PC steel rod 1 is maintained even when the anchor member 27 is removed.

  In the case of the first embodiment, the bearing cylinder 7 is removed from the hollow PC steel rod 1 and hardened after the joining concrete is hardened, and the integrity of the hollow PC steel rod 1 and the non-pulling reaction force PC steel rod 6 is obtained. In order to improve the ultimate strength between the concrete members, the adhesive combined rust preventive material 43 made of a time-curing synthetic resin adhesive obtained by appropriately mixing a retarder with a curable adhesive is a hollow PC steel rod 1. It is injected and filled in advance or at an appropriate time from the end opening of the hollow PC steel rod 1, and the length of the non-pull anti-pull is shorter than the length of the hollow PC steel rod 1 disposed on the back side of the hollow PC steel rod 1. A force PC steel rod 6 is inserted, and then a short removal reaction force PC steel rod 24 engaged in series therewith is in series with a non-pull (stationary) reaction force PC steel rod 6 and hollow PC. More than a predetermined push-in amount from the opening end of the steel rod 1 at the entrance side After being arranged so as to come out, the hollow PC steel rod 1 in a state where the support cylinder 7 is screwed into the rear end male screw portion 15 of the hollow PC steel rod 1 and the stopper 19 is screwed into the rear portion of the support cylinder 7. It is better to balance by introducing tension.

  In this embodiment, a long non-pull (stationary) reaction PC steel rod 6 and a short removal reaction PC steel rod 24 are arranged in the hollow PC steel rod 1 by two long and short PC steel rods. The pushing reaction force PC steel material 25 is configured, and the sum of the dimensions of the non-pulling reaction force PC steel rod 6 and the removal reaction force PC steel rod 24 is longer than the dimension of the hollow PC steel rod 1. The removal reaction force PC steel bar 24 projects outside the rear end of the hollow PC steel bar 1. This projecting dimension is the maximum amount of prestress that can be pushed in indirectly by the jack. Thus, the prestress introduction device 4 for joining and concrete is a device that can be mechanically disassembled or assembled.

  As described above, a plurality of joining / concrete prestress introduction devices 4 in which a predetermined tension force is previously introduced into the hollow PC steel rod 1 in the joining / concrete prestress introduction device 4 (in the illustrated case, each of the left and right two stresses). Further explanation will be made with reference to FIGS. 5, 2, and 3. A plurality (20 in the illustrated case) of PC steel members 35 made of solid steel bars are used. From the right end side, the left end steel cap 13, the middle spiral rebar 44 and the right end steel cap 12 are set in this order. The left concrete prestress introduction device 4 and the right concrete prestress introduction device 4 are: The steel caps 12 and 13 are attached at the time of installation or at the end.

  Further, the anchor member 27 on the end holder 8 side of all the joining / concrete prestress introduction devices 4 is removed, and the steel caps 12 and 13 are attached to the steel caps 12 and 13 from the front end side of each joining / concrete prestress introduction device 4 (unit). Set.

  That is, first, on the yard, each through-hole 35a of the steel cap 13 arrange | positioned from the right end part of each PC steel material 35 to the left end part is passed. And the said steel cap 13 is moved to the predetermined position of a rear-end part (left end of FIG. 5). Further, the front end portion of the concrete prestress introduction device 4 is inserted from the outside of the steel cap 13 into the PC steel material insertion through-hole 11, and the base of the joining and concrete prestress introduction device 4 is inserted outside the cap 13. The concrete prestress introduction device 4 is inserted to a predetermined position so that the end side (rear end portion) has a predetermined connection length L. The connection length is a portion where prestress can be introduced into the concrete member among the portions protruding from the precast PC member main body end portion in the concrete prestress introduction device 4, and is approximately up to the front end surface of the support cylinder 7. is there.

  Next, an intermediate portion of the PC steel material 35 is arranged so that the spiral bars 44 arranged in a cross section completed as a precast PC member surround the PC steel materials 35 and the front end side of the prestress introduction device 4 for joining and concrete. And it arrange | positions at the front-end | tip part of the prestress introduction apparatus 4 for joining and concrete for a predetermined length helically.

  Next, each PC steel rod 35 is inserted into each through hole 35a of the steel cap 12 located on the tip end (right end portion in the figure) side and moved to a predetermined position. Further, the distal end portion of each prestress introduction device 4 for concrete arranged on the right side is inserted from the outside of the steel cap 12, and the base end portion of the prestress introduction device 4 for joining and concrete is inserted from the outer surface of the steel cap 12. After inserting the pre-stress introduction device 4 for joining and concrete from the rightmost steel cap 12 so as to ensure a predetermined connection length, so as to ensure the connection length L at a predetermined distance, The anchor member 27 is screwed to the concrete prestress introduction device 4. Further, a nut 60 is screwed into the end male thread portion of each PC steel material 35 in the outer portion of the steel cap 12, and one end side of the coupler 61 is screwed. In addition, although illustration is abbreviate | omitted, each said steel caps 12 and 13, the spiral reinforcement 44, the PC steel material 35, and each prestress introduction apparatus 4 for joining and concrete are bundled by a wire etc., and are unitized.

  Each of the connection lengths L is a portion of the portion 10 arranged so as to extend outward from the steel caps 12 and 13 when the concrete is placed around the portion (bonding). Among the portions that can be particularly adhered, the portion between the steel cap 12 and the steel cap 13 and each anchor member 27 is a portion that can sufficiently introduce a compressive force to the surrounding concrete. It is an important part.

  From the assembled and unitized PC pile reinforcing material unit (each steel cap 12, 13 and PC steel rod 35, pre-stress introduction device 4 for joining and concrete and spiral muscles bound together) The PC member reinforcing material unit 45 is transported to the PC pile manufacturing position by a crane or the like and placed in the lower half side formwork 29a that is divided in half. The side mold 29a is provided with a tension device 63 provided with a movable movable support plate 62 for tension, and the outer portion of the steel cap 13 is inserted into the through hole 62a for inserting the PC steel material in the movable movable support plate 62 for tension. The end portions of the respective PC steel materials 35 are inserted and engaged with nuts 64 on the outer side of the movable movable support plate 62 for tension.

  In addition, the concrete prestress introduction device groove 62b provided at equiangular intervals on the tension movable support plate 62 is provided with the support cylinder 7 and the anchor member 28 in the concrete prestress introduction device 4 and the hollow PC steel rod. The PC member reinforcing unit 45 is disposed at a predetermined position through the intermediate portion 1.

  The tension device 63 includes a support nut 66 that is screwed onto the distal end side of a tension bolt 65 whose head is engaged with the tension movable support pressure plate 62, and is connected to the side mold 29a. The supporting nut 66 is engaged with the outer side of the end plate 67, and the movable piston in the jack 68 is configured to be connected to and disconnected from the pulling bolt 65 by a coupler (not shown). Also, the coupler 61 on the right side of FIG. 5 is connected to one end of a connecting rod 69 made of a screw having male threads at both ends, and the other end of the connecting rod 69 is connected to the other end of the side mold frame 29a. It is inserted into a fixed bearing plate 70 fixed to the part by bolts and nuts, etc., engaged with the outside of the stationary bearing plate 70, and engaged with the stationary bearing plate 70 by a nut 71 screwed into the connecting rod 69. doing.

  Then, as the jack 68 is shortened, a tension force (tensile force) is introduced into each PC steel material 35 via the tension bolt 65 and the tension movable support plate 62, and the reaction force is applied to the side mold 29. Further, balancing is performed via the fixed bearing plate 70 and the connecting rod 69 and the like. Further, the support nut 66 is engaged with the end plate 67. In this state where the support nut 66 is engaged with the end plate 67, the jack 68 can be removed.

  A nut that is screwed into the PC steel rod 35 may be disposed between the outside of the steel cap 13 and the movable support plate 62. When the nut is disposed in this way, each PC steel 35 is tensioned. In this state, the nut can be engaged with the outer surface of the steel cap 13 to prevent the displacement thereof, and can be immediately engaged and fixed to the steel cap 13 when the support nut 66 is loosened. . The right nut 60 has the same effect. In addition, in order to hold the position of the steel cap 13, you may make it provide the convex part engaged with the outer surface of the steel cap 13 in the side mold frame 29 (29a, 29b) suitably.

  After this, the upper half side mold frame 29b is placed on the side mold frame 29a and integrated and closed with a bolt or the like to form the cylindrical mold frame 29.

  The lower half side mold 29a is placed on a flanged rotary roller 46, and a fixed semi-annular flange is fitted to the middle part of each side mold 29a, 29b. It is set as the annular member rotated. Note that the end plate 67 and the fixed bearing plate 70 are fixed to the end flanges 47 and 48 provided integrally with the end portions of the side molds 29 a and 29 b by bolts and nuts 49.

  Next, a mortar injection pipe 51 is inserted through the fixed bearing plate 70 and the central through hole of the steel cap 12, and a predetermined amount of concrete (or mortar) 52 is put into the mold 29 from the mortar injection pipe 51. Then, the rotary roller 46 is driven to rotate the mold 29 at a predetermined rotational speed to perform centrifugal molding. After the concrete (or mortar) 52 exhibits a predetermined strength, the support nut 66 is loosened (prestress is introduced into the concrete 52 by the PC steel material 35), and the outer mold frame 29b is removed and the nut 64 is removed. The coupler 61 is removed from the PC steel material 35, the mortar injection pipe 51 is removed, the tensile movable support plate 62 is moved backward, and the nut 64 is engaged with the steel cap 13 with an appropriate washer interposed, and the nut The precast PC member 3 made of PC pile is completed by removing the side mold frame 29a by fixing 60 with a steel cap 12 with an appropriate washer interposed therebetween. (The state of FIGS. 1 to 3)

  As described above, in the precast PC member 3 of the present invention, even when the concrete (or mortar) 52 is hardened, the concrete 52 is adhered to the front end side of the prestress introduction device 4 for joining and concrete. The tension force introduced into the hollow PC steel rod 1 is not released and the concrete (or mortar) 52 is in a state where no compressive force (prestress) is introduced.

  It should be noted that when the tension force is introduced to the hollow PC steel rod 1 in the pre-stress introduction device 4 for joining and concrete (in other words, a push-in consisting of a reaction force PC steel rod 6 as a compression rod and a removal reaction force PC steel rod). The reaction force PC steel rod 25 is introduced at the manufacturing plant of the prestress introduction device 4 for joining and concrete. Such an apparatus may be an appropriate apparatus other than the apparatus described above.

  In this embodiment, as shown in FIG. 4, the reaction force PC steel rod 6 and the pushing reaction force PC steel rod 25 composed of the removal reaction force PC steel rod are used as the compression rod, and the hollow PC steel rod 1 is jacked. The PC steel rod 25 is compressed while pulling, and the amount of deformation is rotated to the rear end of the press locking piece 23 by rotating the stopper 19 to maintain the prestressing force. Moreover, since the end holder 8 is screwed inside the end portion of the hollow PC steel rod 1 even if the anchor member 27 is removed, the prestressing force is released at the front end portion of the joint / concrete prestress introduction device 4. The structure is not. Accordingly, by removing the anchor member 27 and allowing the pre-stress introduction device 4 for joining and concrete to pass through the steel groove bottom plate portions of the caps 12 and 13, it is devised that it is not necessary to provide a large through hole in the steel plate. ing. The joining / concrete prestress introducing device 4 may be replaced with a mere PC steel material, or may be replaced with a PC steel material provided with the anchor material 27.

  Next, the precast PC member 3 of the second embodiment of the present invention in which the arrangement of the prestress introduction device 4 for joining and concrete is different with the precast PC member 3 similar to the above will be described with reference to FIGS. To do.

  The precast PC member 3 of the second embodiment has a form in which the arrangement form of the prestress introduction device 4 for joining and concrete is changed. For example, when the precast PC member 3 is used for a diagonal member in a truss bridge or the like, depending on the installation location, the bending moment acting on the diagonal member may be such that the generation of tensile stress is reversed at the upper and lower edges of the precast member. There is a material, and it is a form that is an economical precast PC member 3 that can be used in such a part.

  More specifically, as shown in the explanatory diagram of FIG. 18, when both ends of the precast member are joined to another member (a cast-in-place concrete member or a precast member), a bending moment and an axial tensile force as illustrated are applied. In some cases, tensile stress acts on the upper end (upper left) of one end of the central precast member (the portion corresponding to the precast PC member of the present invention), and smaller than the compressive stress or upper tensile stress on the lower end (lower left). In some cases, tensile stress is applied, tensile stress is applied to the lower end of the other end (lower right), and compressive stress or lower tensile stress is applied to the upper portion of the other end (upper right). In the above, the pre-stress introduction device 4 for joining and concrete or the PC steel material for joining is disposed on the upper end (upper left) and the lower end (lower right) of the other end, and other members Place concrete member or precast member) and ligated to introduce tension to PC member, the coupling by introducing a prestress both members becomes economical precast member which can be canceled tensile stress.

  In the illustrated form suitable for the above case, a plurality of prestress introduction devices 4 for joining and concrete arranged on one side of the precast PC member 3 shown in the left side of FIG. 6A and FIG. A plurality of joints arranged at a position displaced to one end side in the radial direction (the thickness direction of the member) of the precast PC member 3 and arranged on the right side of FIG. 6A and the other end side of the precast PC member 3 shown in FIG. The pre-stress introduction device 4 for concrete and concrete is configured to be disposed at a position displaced to the other end side in the radial direction (the thickness direction of the member) of the precast PC member 3. Since the other configuration is the same as that of the precast PC member 3 of the above-described embodiment, the same parts are denoted by the same reference numerals and the description thereof is omitted.

  Next, as a representative form to show that the prestressing device 4 for joining and concrete in each of the above embodiments can be replaced with a normal PC steel material, the prestressing for joining and concrete of the first embodiment is used. A third embodiment in which the stress introducing device 4 is replaced with a joining PC steel will be described with reference to FIGS. 9 and 10.

  In this embodiment, the connecting PC steel material 4a is a connecting PC steel rod 1b made of a solid steel rod having male thread portions 14 and 15 at both ends. Further, in the state where the anchor member 27 is screwed into the male threaded portion 14 at one end of the connecting PC steel rod 1b in the same manner as the prestress introducing device 4 for joining and concrete, the precast PC member 3 main body concrete is put into the concrete. A fixing nut 28a is screwed into the male thread 15 at the other end of the connecting PC steel rod 1b. The fixing nut 28a is removed as appropriate, inserted into another member (a through-hole of a precast member or a cast-in-place concrete member), and in a state where tension is introduced, compression prestress is applied to both members. Is given and connected. The connecting PC steel material 1a may be a PC steel rod, a PC steel stranded wire, or the like. Since other configurations are the same as those of the above-described embodiment, the same parts are denoted by the same reference numerals and the description thereof is omitted.

  Next, an embodiment in which the precast PC member 3 of the above embodiment is used will be described with reference to FIG. 11 and FIG. 12. This embodiment is the same as the precast PC member 3 of the first embodiment as a beam material or a ceiling. It is used as a wall component or the like, and is connected to other members (cast-in-place concrete member or precast member 54) in such a manner that a tensile stress acts on both ends of the lower edge side of the precast PC member 3. When the precast PC member 3 of the present invention is used in such a form, it can be a low-cost beam material or a ceiling wall constituent member.

  Next, an embodiment in which the precast PC member 3 of the second embodiment is used will be described with reference to FIG. 13. FIG. 13 shows the precast PC member 3 made of the PC pile manufactured as described above. A connection structure between the PC pile 3 and the graded concrete member 39 in the case where (hereinafter also referred to as PC pile 3) is used as the tensile diagonal member 38 of the concrete truss bridge 37 is shown. Even in such a case, the pre-stress introduction device 4 for joining and concrete (or the joining PC steel material 4a) is disposed on the side where the tensile stress of the precast PC member 3 is increased in the portion where the stress state is as shown in FIG. By using the precast PC member 3, the truss bridge girder can be economical. In the case of the PC steel material 4a for joining, since it should just fix with a nut, the prestress introduction apparatus 4 for joining and concrete is demonstrated here.

  In the prestress introduction device 4 for joining and concrete, the length necessary for connection is extended from the upper and lower ends of the PC pile 3 in order to connect to the grade concrete member 39. Moreover, although the side to which the support cylinder (different diameter holder) 7 is attached is set to the outside, it is arranged at a predetermined position, and although not shown, a formwork and necessary reinforcing bars are arranged. By arranging the PC pile 3 in this way, the formwork is arranged so as to provide a notch 53 for removing the support cylinder 7 at the upper and lower rating points.

  Next, grade concrete 39a is placed, and after each grade concrete 39a exhibits a predetermined strength, the stopper 19 in the pre-stress introduction device 4 for joining and concrete is loosened with a wrench, and the tension of the hollow PC steel 1 is reduced. Prestress is simultaneously introduced into the tensile diagonal member 38 and the graded concrete member 39 so as to release. In particular, prestress is introduced between the anchor members 27 and 28 and the adhesion of the hollow PC steel bar 1 to the concrete (or mortar) 52 and the graded concrete 39a.

  Thereby, prestress is also introduced into the connection surface A of the PC pile 3 and each graded concrete member 39, and the PC pile 3 and the graded concrete member 39 can be firmly joined. After that, as shown in FIG. 14, each notch 53 is filled with a rust preventive filler 73 such as mortar to prevent rust at the end of the hollow PC steel rod 1.

  The support cylinder 7 (different diameter holder 7) at the notch 53 is removed, and after removing the short removing reaction force PC steel rod 24, rust prevention such as mortar is provided at the notch 53. Material is filled.

  When implementing the precast PC member 3 of the present invention, although not shown in the figure, the joint / concrete prestress introduction device 4 or the jointing PC steel 4a is disposed only on one end side in the longitudinal direction of the precast PC member. May be. Such a form is a form for applying to the form in which the concrete member for joining is provided only at one end side of the precast PC member 3, and therefore the connection length is provided only on one side, and the joint part is provided only on one side. It is a form to have.

  As the precast PC member 3 of the present invention, not only a PC pile formed by centrifugal force as in the above embodiments, but also a precast PC member 3 having a rectangular hollow cross section or a solid cross section (solid cross section) as shown in FIG. ). Reference numeral 75 denotes a concrete end plate.

  Further, the cross-sectional shape of the precast PC member 3 is not limited to a circular or rectangular hollow cross-section, but is a polygonal cross-section such as a hexagonal cross section or an octagonal cross section, or an appropriate cross-sectional shape such as a T-shaped cross section or an I-shaped cross section. However, the range of use of the precast PC member of the present invention can be used for many purposes.

  Further, the precast PC member 3 of the present invention is required at one end or both ends of the precast PC member 3 in the case of a thin concrete member or a curved concrete member in which a long PC steel material cannot be bent and arranged, or a short precast PC member 3. Even when a prestress is applied by an axial force, it is possible to easily apply an axial force by arranging a small number of pre-stress introduction devices 4 for joining and concrete or a PC steel material 4a for joining at the end of the member. it can.

  In this invention, since it is the form which arrange | positions the prestress introduction apparatus 4 for joining and concrete only to the edge part side of the precast PC member 3, compared with the case where it arrange | positions over the full length of the precast PC member 3, it is economical. Is.

  In the case of the embodiment, the steel caps 12 and 13 having the peripheral plates 12b and 13b are shown. However, when the present invention is implemented, the peripheral plates 12b and 13b of the steel caps 12 and 13 are used. It may be omitted and a steel end plate having only the groove bottom plates 12a and 13a may be used.

(Function)
The conventional pre-tension type PC member is to introduce pre-stress into concrete by releasing the jack at the end of the member immediately after placing concrete in a factory etc. The precast PC member according to the present invention includes a PC steel material in a state where prestress is applied to the concrete and a prestress introduction device 4 for bonding concrete or a PC steel material for bonding which does not prestress the concrete. . After loading the precast PC member 3 into the construction site of the PC structure, place the precast PC member 3 at a predetermined position in the structure, place the concrete of another concrete member to be connected, or place the precast member in advance. The prestress introduction device 4 for joining and concrete provided is released or the PC steel material for joining is fastened, and prestress is applied to the precast PC member 3 and other members simultaneously so as to cancel the tensile stress. One member or the like can be firmly connected.

  The pretension type precast PC member 3 provided with the joint / concrete prestress introduction device 4 is manufactured at the factory and, at the time of shipment, the prestressing force (tensile) is applied to the hollow PC steel in the joint / concrete prestress introduction device 4. Force) is introduced, but prestress is not yet introduced into the concrete body portion of the precast PC member 3 by this. In this state, a trailer or the like is used, a support base is mounted on the trailer or the like, and the precast PC member 3 is loaded on the support base and transported to the construction site.

  At that time, the precast PC member 3 is bent, and the precast PC member 3 is composed of a solid PC steel bar which is tension-fixed, a hollow PC steel bar 1 and a PC steel bar inserted therein. Since 6 (having substantially the same strength as a hollow PC steel rod) jointly has a reinforcing strength as a reinforcing bar, there is no fear of bending cracks. In the pretension type precast PC member 3 provided with the joining PC steel material 4a, the solid PC steel rod and the joining PC steel material 4a jointly have reinforcement strength as a reinforcing bar. There is no concern about bending cracks.

In addition, precast PC member 3 and other concrete members (precast member or cast-in-place concrete member, especially the latter member) are placed on-site with concrete and after exhibiting a predetermined strength, pre-stress for jointing and concrete is introduced. The prestress is introduced into the precast PC member 3 and the other concrete member at the same time by rotating the stopper 19 of the apparatus 4 with a wrench to loosen it or fixing the joining PC steel material 4a. The concrete structure composed of the member 3 and the concrete member joined becomes a pre-stress structure, and can be joined more firmly than the method of joining with bolts or reinforcing bars.

BRIEF DESCRIPTION OF THE DRAWINGS The precast PC member which concerns on 1st Embodiment of this invention is shown, Comprising: (a) is a partially notched side view, (b) is the partially notched longitudinal side view which expanded (a). (A) is a longitudinal side view showing an enlarged left end portion of FIG. 1 (a). (A) is the sectional view on the AA line of FIG. 2, (b) is the sectional view on the BB line of FIG. FIG. 5 is a partially cut-away enlarged vertical side view showing an enlarged view of the different diameter holder side and the end holder side in the joint and concrete prestress introduction device. It is a vertical side view for demonstrating the manufacturing method of the precast PC member of this invention. The precast PC member which concerns on 2nd Embodiment of this invention is shown, Comprising: (a) is a partially notched side view, (b) is the partially notched longitudinal side view which expanded (a). (A) is CC sectional view taken on the line of FIG. 6 (a), (b) is sectional drawing of the center part vicinity of FIG.6 (b). It is the DD sectional view taken on the line of Fig.6 (a). The precast PC member which concerns on 3rd Embodiment of this invention is shown, Comprising: (a) is a partially notched side view, (b) is the partially notched longitudinal side view which expanded (a). (A) is the EE sectional view taken on the line of FIG. 9, (b) is sectional drawing of the center part vicinity of FIG. 6a. It is a figure which shows the usage condition of the precast PC member of this invention. It is a figure which shows the usage condition of the precast PC member of this invention. It is a partially longitudinal side view which shows the form which applied the precast PC member of this invention to the truss bridge. 13 is a partially longitudinal side view showing a state in which the stopper is loosened and the precast PC member and the grading member are joined together, and then the different diameter holder is removed and the concave portion of the grading member is filled with rust-preventing mortar. It is. (A) is a partially longitudinal side view showing one end side of another precast PC member in the present invention, and (b) is a sectional view taken along line FF in (a). It is a vertical side view for demonstrating the manufacturing method of the conventional precast PC member. (A) is a side view which shows a concrete truss bridge, (b) is a side view which shows the junction structure of the grade part of the diagonal and the string material in the conventional concrete truss bridge. It is stress explanatory drawing of a precast member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hollow PC steel bar 1a Steel hollow PC steel bar main body 1b Connecting PC steel bar 2 Concrete 3 Precast PC member 4 Bonding and prestress introduction device for concrete 4a Bonding PC steel 6 PC steel bar 7 Bearing cylinder (different diameter holder )
8 End Holder 9 Member End 10 Portion Extending Outside 11 PC Steel Through Hole 12 Steel Cap 13 Steel Cap 14 Male Screw Part 15 Male Thread Part 16 Small Diameter Female Thread Hole 17 Large Diameter Female Thread Hole 18 Rotation Tool engaging outer surface 19 Stopper 20 End male threaded portion 21 Rotating tool engaging outer surface 22 Recess 23 Press locking piece 24 Removal reaction force PC steel rod 25 Pushing reaction force PC steel rod 26 Female screw hole 27 Anchor member 28 Anchor member 29 Formwork 29a Side formwork 29b Side formwork 30 Side formwork 31 Outer frame 32 Outer frame 33 End plate 34 End plate 35 PC steel material 36 Jack 37 Concrete truss bridge 38 Tensile member 39 Grade member (grade concrete member)
40 Precast PC member 41 Steel flange 42 Bolt or nut 43 Adhesive rust preventive material 44 Spiral reinforcement 45 PC member reinforcing unit 46 Rotating roller 47 with flange End flange 48 End flange 49 Bolt / nut 51 Mortar injection pipe 52 Concrete (Or mortar)
53 Notch 54 Cast-in-place concrete member or precast member 60 Nut 61 Coupler 62 Pulling movable support plate 62a Through hole 62b Groove 63 Tensioning device 64 Nut 65 Pulling bolt 66 Bearing nut 67 End plate 68 Jack 69 Connecting rod 70 Fixed support Pressure plate 71 Nut 72 Concrete pier 73 Antirust filler 75 Concrete end plate

Claims (5)

  A precast PC member in which an intermediate portion of the PC steel material is embedded in the cross section of the precast PC member, and an end portion of the PC steel material is fixed to the precast PC member main body and prestress is applied to the precast PC member main body ( In 3), the front end side of the PC steel material 1 for bonding is embedded in advance in the cross section on the side mainly bearing the tensile stress at one end portion or both end portions of the precast PC member (3) separately from the PC steel material, The base end portion of the joining PC steel material (1) is arranged to extend outward from the main body end portion of the precast PC member (3), and from the main body end portion (9) of the precast PC member (3). A precast PC member characterized in that a joint portion is constituted by a portion (10) arranged so as to extend outward.   A precast PC member in which an intermediate portion of the PC steel material is embedded in the cross section of the precast PC member, and an end portion of the PC steel material is fixed to the precast PC member main body and prestress is applied to the precast PC member main body ( 3) In addition to the PC steel material, a prestressing device for joining and concrete pre-tensioned in a cross section on the side mainly bearing the tensile stress at one end or both ends of the precast PC member (3) ( 4) The hollow PC steel rod (1) in the tip side is embedded and arranged. In the device (4), a reaction force PC steel rod is inserted into the hollow PC steel rod (1). A tension force is introduced into the hollow PC steel rod (1) in advance while applying a force, and a prestressing force is applied to the concrete by releasing the tension force. And a support cylinder (7) having a stopper (19) screwed to the base end of the hollow PC steel rod (1), and a screw at the tip of the hollow PC steel rod (1). The prestressing force of the hollow PC steel rod (1) is held by the joined end holder (8), and the base end of the device (4) is the main end of the precast PC member (3). Of the hollow PC steel rod (1) by a portion (10) arranged so as to extend outward from the portion and extended outward from the main body end (9) of the precast PC member (3). A precast PC member characterized in that a joint portion in which a prestressing force is maintained is formed.   A female screw hole (26) is provided inside the tip of the hollow PC steel rod (1), an end holder (8) made of a male screw member is provided in the female screw hole (26), and the hollow PC steel rod (1 3. A precast PC member according to claim 2, wherein a male screw part (14) is provided outside the tip of said male screw part (14), and an anchor member (27) is screwed into said male screw part (14). .   The joining PC steel (1) or joining / concrete prestress introduction device (4) disposed at one end and the other end of the precast PC member (3) is connected to one end of the precast PC member (3) and the other. 4. The precast PC member according to claim 1, wherein the precast PC member is disposed on the same side or a different side in the member thickness direction of the precast PC member 3. After the precast PC member (3) according to any one of claims 1 to 4 is arranged at a predetermined position to build a concrete structure, a portion (10) extended to the outside of the precast PC member main body is used. Then, prestress is introduced into both the precast PC member (3) and the other concrete member, and a concrete structure composed of the precast PC member (3) and the other concrete member is integrated. A method of joining a precast PC member and another member.

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