JP5099829B2 - Precast prestressed concrete components - Google Patents

Description

  The present invention relates to a precast prestressed concrete member in which a tension force is applied to a tension material embedded therein by a pretension method.

  Precast prestressed concrete (hereinafter abbreviated as PCaPC) members are reinforced concrete members manufactured in factories, etc., which provide high dimensional accuracy and are pre-stressed in advance. And prestress introduction work is not required, and the construction period can be shortened.

FIG. 3 shows a PCaPC beam manufactured by a pre-tension method which is a kind of the conventional PCaPC member.
The PCaPC beam 1 has upper end bars (reinforcing bars) 2 and lower end bars (reinforcing bars) 3 disposed in a mold (not shown), and a plurality of PC steel members 4 are disposed above the lower end bars 3 in advance. The PC steel material 4 is manufactured by placing the concrete 5 in the formwork in a tensioned state and hardening it, then releasing the tension and dismantling the formwork.

  FIG. 4 shows another conventional PCaPC beam. This PCaPC beam 6 has an upper bar (rebar) 7 and a lower bar (rebar) 8 disposed in a mold not shown in the figure, The concrete 9 is manufactured by placing the concrete 9 in the mold in a state in which the lower end reinforcement 8 is previously tensioned and hardening it, and then releasing the tension and disassembling the mold.

  According to these PCaPC beams 1 and 6, by applying tension to the PC steel material 4 and the lower reinforcement 8 arranged below the neutral axis, the PC steel 4 or the lower reinforcement 8 and the concrete 5, The prestress is introduced in the longitudinal direction by the adhesive force with 9. As a result, it is possible to obtain a large bending-proof moment with respect to the vertical load at both ends supported by the eccentric moment, and since it does not crack against bending, it can be suitably used as a building beam forming a large span space. There is an advantage that you can.

  However, in the PCaPC beams 1 and 6, the prestress is introduced by the PC steel material 4 and the lower end reinforcement 8, so that the rigidity is high and the linearity is strong. Therefore, there is a problem in that the floor vibration lasts for a long time and thus adversely affects the comfortability. In particular, when used as a beam for forming the above-mentioned large span, the possibility that the floor vibration is generated is further increased, so that the above-described adverse effect due to the persistence of the floor vibration becomes significant. It was.

  This invention is made | formed in view of this situation, and makes it a subject to provide the PCaPC member which was excellent in rigidity and bending-proof moment, and the damping property with respect to the vibration improved.

In order to solve the above-mentioned problem, the invention according to claim 1 is arranged such that the upper and lower bars are arranged, and prestress is introduced into the tension material disposed below the neutral axis. a precast prestressed concrete member of the pre-tensioning, the longitudinal end portion of the, with fixing region of the tensioning member is formed, at least one of the upper muscle and lower muscle of the central portion located between the fixing region Attenuating material that absorbs vibration is wound around one of the outer circumferences.

  Here, the invention described in claim 2 is characterized in that, in the invention described in claim 1, the tension material is a PC steel material disposed adjacently above the lower end bars.

  The invention described in claim 3 is characterized in that, in the invention described in claim 1, the tendon is a lower streak.

  Furthermore, the invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the damping material is a high damping rubber, and the upper and lower bars are wound around the high damping rubber. It is affixed on at least one of the outer peripheral surfaces.

  According to the PCaPC member according to any one of claims 1 to 4, since prestress is introduced by the adhesive force between the tension material fixed to both end portions in the longitudinal direction and the concrete, it is generated thereby. The eccentric moment increases the rigidity, and a large bending-proof moment can be obtained with respect to the vertical load at the both end supports.

  In addition, in this PCaPC member, since a damping material is wound around the outer periphery of at least one of the upper and lower stripes in the central portion located between the fixing regions, this occurs in the PCaPC member. The above vibration can be absorbed and attenuated by the damping material.

  In particular, in the present invention, since the damping material has a large amount of deformation and is therefore provided at an intermediate portion in the longitudinal direction that is effective for improving the damping property, it is possible to obtain a high damping property, It is possible to obtain an effective damping property against minute vibrations such as vibrations, thereby improving the comfortability. In addition, it is preferable to wind the said attenuation | damping material continuously without leaving a clearance gap.

  Here, as the above-mentioned tension material, as in the invention described in claim 2, PC steel material arranged below the neutral shaft and adjacent to the upper end of the lower end bar can be used. As in the invention described in Item 3, a lower end line can be used.

  Further, as the damping material, a high damping rubber is suitable as in the invention described in claim 4. When this high damping rubber is used, it can be mounted by forming the high damping rubber in a band shape and continuously winding it on the outer periphery of the upper and / or lower end bars. In addition, since the high damping rubber can be molded into an arbitrary shape, it is formed in a cylindrical shape, and the upper and / or lower end stripes are inserted into the hollow portion, or a cut along the longitudinal direction is made. It can be mounted by putting a cover on the outer circumference of the upper and / or lower end bars.

  In either case, if the damping material is applied to the outer periphery of the upper and / or lower end muscles, the damping material can be reliably deformed and absorbed with respect to vibration. It is preferable because the attenuation can be effectively improved.

(First embodiment)
FIG. 1 shows a first embodiment in which a PCaPC member according to the present invention is applied to a PCaPC beam.
This PCaPC beam 10 also has an upper end bar (rebar) 11 and a lower end bar (rebar) 12 disposed in a mold (not shown), and a plurality of PCs above the lower end bar 12 and below the neutral axis. It is manufactured by disposing the above-mentioned formwork after placing the steel material 13 and placing and hardening the concrete 14 in the formwork in a state in which the PC steel material (tension material) 13 is pre-tensioned. The points are the same as those shown in FIG.

  However, in this PCaPC 10, a high damping rubber (attenuating material) 15 is provided in the longitudinal direction at the center portion located between the fixing regions of the PC steel material 13 formed at both ends in the longitudinal direction on the outer periphery of the lower end reinforcement 12. It is wound continuously in the direction.

  The high-damping rubber 15 is mounted by winding a belt-shaped member around the outer periphery of the lower end muscle 12. Alternatively, the high-damping rubber 15 may be formed in a cylindrical shape, and the lower end muscle 12 may be inserted into the hollow portion, or a cut along the longitudinal direction may be formed and the outer circumference of the lower end muscle 12 may be covered. . Here, as this high damping rubber 15, for example, a self-adhesive high damping rubber such as a self-adhesive acrylic rubber is used in order to attach the inner peripheral surface and the outer peripheral surface of the lower end muscle 12. Is preferred.

(Second Embodiment)
FIG. 2 shows a second embodiment of the PCaPC beam according to the present invention.
This PCaPC beam 20 has an upper end rebar (rebar) 21 and a lower end rebar (rebar) 22 arranged in a mold (not shown), and an outer periphery of the lower end rebar 22 and a central portion excluding both end portions in the longitudinal direction. In addition, the high damping rubber (damping material) 23 is continuously wound in the longitudinal direction, and the concrete 24 is placed and cured in the mold in a state where the lower end reinforcement 22 is tensioned in advance. It is manufactured by dismantling the formwork.

As a result, the lower end reinforcement 22 has a high-attenuating rubber (attenuating material) 23 continuously wound in the longitudinal direction around the outer periphery of the central portion located between the fixing regions formed at both end portions in the longitudinal direction. Yes.
The high-damping rubber 23 is also wound around the outer periphery of the lower end bar 22 in the same manner as that shown in the first embodiment. In addition, it is preferable that the high-attenuation rubber 23 is attached to the inner peripheral surface and the outer peripheral surface of the lower end stripe 22 by using the above-described self-adhesive acrylic rubber or the like.

  According to the PCaPC beams 10 and 20 having the above-described configuration, prestress is introduced by the adhesion between the PC steel material 13 or the bottom reinforcement 22 fixed to both ends in the longitudinal direction and the concrete 14 and 24. The eccentric moment generated thereby increases the rigidity, and can obtain a large bending-proof moment with respect to the vertical load at both ends.

  In addition, in these PCaPC beams 10 and 20, high attenuation rubbers 15 and 23 are continuously wound around the outer periphery of the lower end stripes 12 and 22 in the central portion located between the fixing regions. The vibration generated in the beams 10 and 20 can be absorbed and damped by the high damping rubbers 15 and 23.

At this time, the high damping rubbers 15 and 23 are provided at intermediate portions in the longitudinal direction, which are effective for improving the damping property, and the high damping rubbers 15 and 23 and the lower end stripes 12 and 23 are provided. Since 22 is affixed, it is possible to obtain a high damping property by reliably deforming the high damping rubbers 15 and 23 with respect to vibrations, and thus effective against fine vibrations such as floor vibrations. Since attenuation can be obtained, comfort can be improved.

  In the first and second embodiments, only the case where the high-damping rubbers 15 and 23 are wound around the outer periphery of the lower end bars 12 and 22 has been described. You may wind around the outer periphery of 11 and 21, or may wind around the outer periphery of both the upper end reinforcements 11 and 21 and the lower end reinforcements 12 and 22.

  Further, the damping material wound around the outer periphery of the upper end bars 11 and 21 and / or the lower end bars 12 and 22 is not limited to the above-described high damping rubbers 15 and 23, and is a material having damping properties against vibrations. Other damping materials can also be applied as long as they are made of.

It is a figure which shows 1st Embodiment of the PCaPC member which concerns on this invention, (a) is a longitudinal cross-sectional view, (b) is the sectional view on the AA line of (a). It is a figure which shows 2nd Embodiment of the PCaPC member which concerns on this invention, (a) is a longitudinal cross-sectional view, (b) is the sectional view on the AA line of (a). It is a figure which shows the conventional PCaPC beam, (a) is a longitudinal cross-sectional view, (b) is a longitudinal cross-sectional view which is the AA sectional view taken on the line of (a). It is a figure which shows the other conventional PCaPC beam, (a) is a longitudinal cross-sectional view, (b) is a longitudinal cross-sectional view which is a longitudinal cross-sectional view which is the AA sectional view taken on the line (a).

Explanation of symbols

10, 20 PCaPC beam (PCaPC member)
11, 21 Upper muscle 12 Lower muscle 13 PC steel (tensile material)
14, 24 Concrete 15 23 High damping rubber (damping material)
22 Lower end muscle (tension material)

Claims (4)

A precast prestressed concrete member of a pretension system in which prestress is introduced into a tension material disposed below the neutral axis, with upper and lower bars being laid out,
The longitudinal end portion of the, with fixing region of the tensioning member is formed, on at least one of the outer periphery of the upper muscle and lower muscle of the central portion located between the fixing region, the damping member that absorbs vibrations Is a precast prestressed concrete member characterized by being wound.   The precast prestressed concrete member according to claim 1, wherein the tendon is a PC steel material disposed adjacently above the lower end bars.   The precast prestressed concrete member according to claim 1, wherein the tendon is the lower reinforcement.   4. The damping material according to claim 1, wherein the damping material is a high damping rubber and is affixed to an outer peripheral surface of at least one of the upper and lower reinforcing bars around which the high damping rubber is wound. The precast prestressed concrete member according to any one of the above.

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