JP2913471B2 - PC steel bar unit with safety means at break - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a P-type member in which a tensile force is previously introduced to introduce a compressive stress to a concrete member.
The present invention relates to a C steel bar unit, and more particularly, to a PC steel bar unit that is safe even if a member breaks before construction.

[0002]

2. Description of the Related Art When prestress is introduced into a connection portion of a precast concrete member or prestress is introduced into an anchor or the like embedded in the ground, the end of a PC steel material is fixed by a support plate, a nut and a washer. Prestress is introduced by tightening the nut with a tensioner such as a jack.

[0003] In the above-mentioned conventional PC steel material, since all operations for introducing tension must be performed at the construction site, a tension introduction device such as a jack used for the tension introduction work becomes large-scale. Handling was difficult in narrow work spaces such as scaffolds. In order to solve such a problem, the present applicant has proposed a PC steel rod unit capable of introducing prestress into a concrete member by a simple operation at a construction site, and has disclosed Japanese Patent Application No. Hei 6-31889.
No. 1 and Japanese Patent Application No. 8-30263 filed a patent application. That is, as shown in FIG. 3, the PC steel rod unit 10 has a cylindrical hollow PC steel rod 11 having at least one open end, and is inserted into the hollow PC steel rod 11 to receive a compressive force. While maintaining the solid PC steel rod 12 for the reaction force and the compressive force introduced into the solid PC steel rod 12,
A detachable tension holding means 13 for transmitting the compressive force to the hollow PC steel rod 11 as a tensile force is provided. By removing the tension holding means 13b, a force to contract the hollow PC steel rod 11 is applied. Acts and introduces prestress into the outer concrete.

[0004]

However, the above P
If the hollow PC steel bar 11 or the tension holding means 13 is damaged before the C steel bar unit 10 is embedded and fixed in the concrete member, the tensile force introduced into the hollow PC steel bar 11 is released, It has been pointed out that the danger of the hollow PC steel rod 11 popping out.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional PC steel bar unit. The problem is that, before embedding in a concrete member and fixing it, the member of the PC steel bar unit is broken. In particular, it is an object of the present invention to provide a PC steel rod unit having no danger of the member jumping out.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cylindrical steel rod having at least one open end, and a compressive force inserted into the cylindrical steel rod to introduce a compressive force. A steel rod for reaction force, a detachable tension holding means for holding the compression force introduced to the reaction force steel rod, and transmitting the compression force to the cylindrical steel rod as a tensile force; Provided is a PC steel rod unit including an uncured viscous material that fills a gap between a cylindrical steel rod and the reaction steel rod and exhibits a hardening action after a lapse of a predetermined time.

Further, in the present invention, a connecting member which is separately connected to both ends of the reaction steel bar and protrudes from both ends of the cylindrical steel bar, and a tension holding means directly or at both ends of the cylindrical steel bar. A damping member disposed between the two ends of the tubular steel bar or between the both ends of the cylindrical steel bar or the tension holding means, and a clamping member separately provided near the distal end of the connecting member so as to sandwich the damping member. The present invention provides the above-mentioned PC steel bar unit.

Further, in the present invention, a sealing member for closing a gap between the cylindrical steel bar and the reaction steel bar may be provided near both ends of the cylindrical steel bar. That is, although the uncured viscous material filled in the gap between the cylindrical steel rod and the reaction steel rod can be sealed so as not to leak out of the gap by the tension holding means or the like, By arranging the sealing members near both ends of the cylindrical steel bar, the amount of the viscous material used can be reduced, and the effect of preventing the viscous material from leaking can be further enhanced.

In the PC steel rod unit of the present invention, the viscous material is filled in an uncured state in a gap between the cylindrical steel rod and the reaction steel rod, and exerts a hardening action after a predetermined time has elapsed. Anything is fine. Generally, when using high strength cement, it takes about 3 to 4 days for the concrete to harden to the extent that prestress can be introduced. It takes about 30 days to be installed. Therefore, it is preferable to use a viscous material capable of adjusting the curing in a period of 30 days or more, more preferably 3 months or more. As a viscous material having such a property, there is a so-called room temperature delayed-curing adhesive that cures at room temperature after a predetermined time has elapsed. Examples of the room temperature delayed-curing adhesive include an epoxy resin and a curing accelerator And an amine-based curing agent (0.3% by weight) containing the same, and it takes about 6 months to cure. The main component of the viscous material is not particularly limited. In addition to the above-mentioned epoxy resin as a main component, a resin containing a polyurethane resin or a polyester resin as a main component can be used.

[0010] In the PC steel bar unit of the present invention, the connecting member has an obstacle such that the tensile force acting on the cylindrical steel bar cannot be held before the PC steel bar unit is embedded in the concrete member and fixed. When a force is generated in the cylindrical steel bar or the tension holding means and the force is applied to the cylindrical steel rod or the tension holding means, the popping out is performed via the damping member and the holding member. It suffices if the desired force can be transmitted to the reaction steel bar.

The damping member is provided with an external force (particularly a compressive force).
Is desirably provided with elasticity capable of attenuating this external force when the force acts, and therefore it is not always necessary to restore after the compressive force acts. As such a damping member, a rubber material such as a high damping rubber, a resin material, or the like can be used.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings, but the present invention is not limited thereto.
Here, FIG. 1 (a) is a cross-sectional view for explaining the configuration of the PC steel rod unit of the present invention, and FIG. 1 (b) is an enlarged cross-sectional view of a part of a dotted line Ib in FIG. 1 (a). FIG. 2 is a cross-sectional view for explaining a PC steel bar unit in a mode different from FIG. 1, and is a cross-sectional view of a PC steel bar unit in a mode different from FIGS. 1 and 2.

In the PC steel bar unit 10 shown in FIGS. 1 (a) and 1 (b),
A hollow PC steel rod 11 as a cylindrical steel rod; a solid PC steel rod 12 as a reaction steel rod inserted into the hollow PC steel rod 11 to introduce a compressive force; The detachable tension holding members 13 and 16 for holding the compressive force introduced into the steel rod 12 and transmitting the compressive force to the hollow PC steel rod 11 as a tensile force, the hollow PC steel rod 11 and the solid PC steel A room-temperature delayed-curing adhesive as a viscous material 17 filled in a gap between the rod 12 and an epoxy resin and an amine-based curing agent containing a curing accelerator (0.3% by weight) were mixed. And an adhesive.

In this case, the viscous material 17 is previously hollow P
C steel rod 11 is filled and then solid PC steel rod 12
Or by applying the solid PC steel rod 12 into the hollow PC steel rod 11 while applying it to the surface of the solid PC steel rod 12, It is filled in the gap between the steel rod 12.

The hollow PC steel rod 11 is a PC steel material for directly contributing to the introduction of prestress into a concrete structure or a concrete member, and is formed in a cylindrical shape with both ends open. A screw thread is formed on the outer periphery of. One end of hollow PC steel rod 11 (Fig. 1 (a)
A rubber packing 15 as a sealing member is attached to the middle and left end portions). The rubber packing 15 is formed with a hole through which the solid PC steel rod 12 can penetrate, and the hole is formed in such a size that it is in close contact with the solid PC steel rod 12 so that no gap is formed.

Further, the solid PC steel rod 12 is made of hollow PC.
When a compressive force is introduced by being inserted inside the steel bar 11, a gap of a predetermined length is generated between the outer peripheral surface of the solid PC steel bar 12 and the inner peripheral surface of the hollow PC steel bar 11. 1a, and the length is one end (FIG. 1) as shown in FIG.
(a), the left end of the hollow PC steel rod 11 is formed so as to protrude from the left end of the hollow PC steel rod 11 by a predetermined length.

As the tension holding member 16, a nut formed in a bag shape (a shape with one end closed) can be used. The tension holding member 16 is screwed into a thread at one end (the right end in FIG. 1A) of the hollow PC steel rod 11, seals the opening at the right end, and the solid PC steel rod 12 Is prevented from coming off. On the other hand, the tension holding member 13 is shown in FIG.
(a) a nut 13a screwed into a thread at the left end of the hollow PC steel rod 11, a piece 13c inserted into the nut 13a and in contact with the left end of the solid PC steel rod 12, A hollow bolt 13b is screwed into the thread on the inner periphery of 13a and abuts on the top 13c. This tension holding member 13
As shown in FIG. 1 (a), the opening at the left end of the hollow PC steel rod 11 is sealed with a nut 13a and a hollow bolt 13b, and the solid PC steel rod 12 is prevented from coming out of this opening. Together with the tension holding member 16 at the right end of the PC steel bar 11, the solid PC steel bar 12 is held in the hollow PC steel bar 11 in a compressed state. The top 13c abutting on the left end of the solid PC steel rod 12 takes a reaction force on the solid PC steel rod 12 to introduce tensile force into the hollow PC steel rod 11, that is, the hollow PC steel rod 11 When the solid PC steel bar 12 is pushed in by a jack device (not shown) by taking a reaction force to the above, the pressing force from the jack device is directly received. In a state where the solid PC steel rod 12 is contracted by the pressing force, the hollow bolt 13b is further turned to make contact with the top 13c, and the compressed state of the solid PC steel rod 12 and the hollow PC are passed through the top 13c.
The steel bar 11 is kept in a tensile state.

Next, the operation of the PC steel rod unit 10 will be described. If the hollow PC steel bar 11 of the PC steel bar unit 10 breaks in the middle before the PC steel bar unit 10 is fixed to the concrete member or the concrete structure, the tensile force introduced into the hollow PC steel bar 11 Is not held by the tension holding members 13 and 16, but changes into a force to fly the broken hollow PC steel rod 11 in both directions of the arrow P in FIG. However, the force in the direction of arrow P is
Viscous material 1 filled in gap with solid PC steel rod 12
Since the hollow PC steel rod 11 is attenuated by the adhesive force of 7, the broken PC steel rod 11 scatters only at a speed that does not injure a person even if a person is present in the vicinity. That is, the total length is almost 1
When an experiment was performed in which the hollow PC steel rod 11 was broken in the middle of the PC steel rod unit 10 of about 0 m, when the viscous material 17 was not filled, the broken hollow PC steel rod 11 was scattered about 50 m. Whereas the viscous material 17
In the case of filling with, the broken hollow PC steel rod 11 was scattered only by about 30 cm.

Next, the PC steel rod unit 10 shown in FIG.
Will be described. In the PC steel bar unit 10 of FIG.
Connecting steel bars 32, 32 as connecting members separately connected to both ends (left and right ends in FIG. 2) of the solid PC steel bar 12 respectively.
Plates 30, 30 as clamping members fixed to the tips of the connecting steel bars 32, 32, and the connecting steel bars 32, 32 penetrate substantially through the center, the plates 30, 30, the hollow bolt 13b, and the tension. Damping members 31 and 3 sandwiched between holding members 16
1 is provided. In the embodiment of FIG. 2, unlike FIG. 1, holes through which the connecting steel bar 32 can penetrate are formed in both the top 13c and the tension holding member 16, but other configurations, for example, hollow PC steel A viscous material (not shown) filled in the gap between the rod 11 and the solid PC steel rod 12 is provided in the same manner as in FIG.

In the embodiment of FIG. 2, before fixing,
Hollow PC steel rod 11, nut 13a or hollow bolt 1
When 3b is broken, the tensile force introduced into the hollow PC steel rod 11 is not maintained, and the force is changed to a force to fly the broken hollow PC steel rod 11, the nut 13a or the hollow bolt 13b in both directions of the arrow P in FIG. However, the force in the direction of the arrow P is damped by the viscous material and the damping material 31. That is, when the hollow PC steel rod 11 breaks, the tensile force is attenuated by the adhesive force of the viscous material.
Together with the hollow bolt 13b and the tension holding member 16 which are integrally connected, protrude in both directions of the arrow P and press the damping materials 31, 31 separately. This pressing force is attenuated by the compressive deformation of the damping materials 31, 31, and the attenuated force is applied to the solid P from the plates 30, 30 via the connecting steel rods 32, 32.
C to the steel bar 12, the weight of the solid PC steel bar 12 itself,
It is further damped by the adhesive force of the viscous material. Therefore,
The flying distance of the broken hollow PC steel rod 11 is further suppressed than in FIG.

Further, the PC steel rod unit of the present invention is shown in FIG.
The present invention is not limited to the embodiment shown in FIG. 2 and can be implemented in an embodiment shown in FIG. That is, in the PC steel bar unit 20 shown in FIG. 4, a hollow PC steel bar 21 as a cylindrical steel bar formed by threading a thread 21a on the outer periphery of one end and threading a thread on the inner periphery of the other end. A solid PC steel rod 24 inserted into the hollow PC steel rod 21 to introduce a compressive force;
The full screw bolt 22 as a tension holding means screwed into the screw thread on the inner circumference of the C steel rod 21 and the compressive force introduced to the solid PC steel rod 24 are held together with the full screw bolt 22, and this compression is performed. A detachable tension holding means (coupler 25, top 26 and hollow bolt 27) for transmitting a force as a tensile force to the hollow PC steel rod 24 is provided. The gap is filled with a viscous material (not shown). When the PC steel bar unit 20 is formed as described above, the same operation and effect as those in FIG. 1 can be obtained. Although not shown, the embodiment of FIG. 4 is similar to FIG.
Through holes are provided in the top 26 and all the screw bolts 22, and
If the connecting steel bar, the damping member and the plate are provided, the same operation and effect as in FIG. 2 can be obtained. It is important that the PC steel rod unit of the present invention be used to introduce prestress into concrete structures and concrete members before the viscous material hardens.

[0022]

According to the PC steel rod unit of the present invention, the gap between the cylindrical steel rod and the reaction steel rod is filled with an uncured viscous material that exhibits a hardening action after a predetermined time has elapsed.
Even if the tubular steel bar breaks before the PC steel bar unit is fixed to the concrete member or concrete structure, the force of the tubular steel bar that tries to pop out by the released tensile force is the adhesive force of the viscous material. Attenuated, and even if there are people around,
They only fly at a speed that does not hurt these people.

Further, in the PC steel rod unit of the present invention, the gap between the cylindrical steel rod and the reaction steel rod is filled with an uncured viscous material that exhibits a hardening action after a predetermined time has passed, and the reaction steel rod is formed. A connecting member is separately connected to both ends, and a holding member is provided near the distal end of the connecting member. A damping member is separately held between the holding member and the tension holding means. Therefore, not only when the tubular steel bar breaks, but also when the tension holding means breaks, the force of these broken members trying to scatter is attenuated by the compressive deformation of the damping material, and the clamping member and the coupling member are connected. It is transmitted to the cylindrical steel rod via the member, and can be attenuated by the weight of the cylindrical steel rod itself and the adhesive force of the viscous material.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view for explaining the configuration of a PC steel rod unit of the present invention, and FIG. 1B is a partially cross-sectional enlarged view of a portion indicated by a dotted line Ib in FIG.

FIG. 2 is a view for explaining a PC steel rod unit having a mode different from that of FIG. 1;

FIG. 3 is a sectional view of a conventional PC steel rod unit.

FIG. 4 is a sectional view of a PC steel rod unit in a mode different from FIGS. 1 and 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 PC steel bar unit 11 Hollow PC steel bar (tubular steel bar) 12 Solid PC steel bar (reaction steel bar) 13 Tension holding means 16 Tension holding member (Tension holding means) 17 Viscous material 20 PC steel bar unit 21 Hollow PC steel bar (cylindrical steel bar) 24 Solid PC steel bar (reaction steel bar) 25 Coupler (tension holding means) 26 Top (tension holding means) 27 Hollow bolt (tension holding means) 30 Plate (holding member) 31) Damping member 32 Connecting steel bar (connecting member)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeru Mizoguchi 3-9-28 Nishi-Hachiman, Hiratsuka-shi, Kanagawa Daiya Palace 502 (72) Inventor Yoshihiro Ikegami 301-4, Hiratsuka-shi, Kanagawa Prefecture (58) Investigated Field (Int.Cl. ⁶ , DB name) E04C 5/00-5/20 E04G 21/12 104

Claims (2)

(57) [Claims] 1. A cylindrical steel rod having at least one end opened, a steel rod for reaction force inserted into the cylindrical steel rod to introduce a compressive force, and a steel rod for reaction force. The detachable tension holding means for holding the introduced compressive force and transmitting the compressive force to the tubular steel bar as a tensile force, and filling the gap between the tubular steel bar and the reaction steel bar. And a non-hardened viscous material that exhibits a hardening action after a predetermined time has passed. 2. A connecting member which is separately connected to both ends of the reaction steel bar and protrudes from both ends of the cylindrical steel bar, and the tension holding means is interposed directly or at both ends of the cylindrical steel bar. And a clamping member separately provided near the distal end of the connecting member so as to sandwich the damping member between both ends of the cylindrical steel bar or the tension holding means. Item 2. The PC steel bar unit according to Item 1.