JP2633945B2 - Method and apparatus for manufacturing semi-PC floorboard with small beams - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for manufacturing a semi-PC floor plate with a small beam having a T-shaped or Darull T-shaped cross section.

(Prior Art) Conventionally, when manufacturing the half-PC floorboard with the small beam, the half with the small beam is used.
A reaction force receiving beam (c) that straddles the formwork (a) on supports (b) arranged on both outer sides in the beam width direction of the PC floorboard forming formwork (a).
And pressing jacks (d) are arranged on the reaction force receiving beam (c) at the center in the longitudinal direction of the formwork (a) or at a plurality of points. Next, as shown in FIG. 11, an assembled truss reinforcing bar (e) in which the upper and lower chord members are formed of double reinforcing bars, and the web is formed of lattice bars, and the web is formed in an arc shape, is used as the formwork. The truss rebar (e) is temporarily supported at both ends by vertically arranging it on the beam forming portion (a ') in (a) (see FIG. 12A).
As shown in FIG. 0, the truss reinforcing bar (e) is pressurized through a pressurizing device (d) such as a jack provided on the reaction force beam (c). The truss reinforcing bar (e) is lowered by the same pressing force P until it becomes horizontal (see FIG. 12B).
Reinforcing bars are arranged in the lower half of the floor (a ″), and concrete (f) is cast in this state.
After the cast concrete (f) develops strength, the pressing force by the pressurizing device (d) is released, and the pre-stressed semi-PC floor plate with prestress introduced by the restoring force of the assembled truss reinforcing bar. Has been manufactured. (See FIG. 12D) (Problems to be Solved by the Invention) However, in the above-mentioned conventional method, as shown in FIG. When two places near the center of the truss are pressed, the truss reinforcing bar (e) bends only locally near the pressing point as shown in FIG. 14, and no average stress is introduced into the lattice lattice of the web. Even if the bending of the truss bars is removed after the strength of the cast concrete is released, the restoring force of the assembled truss bars is weak, and the introduction of prestress into the concrete part is uncertain. there were.

The present invention has been proposed in view of the problems of the prior art described above, and a method and apparatus for manufacturing a semi-PC floorboard with small beams, in which required prestress is reliably introduced, and which supports long span floors and unsupported works. The point is to provide.

(Means for Solving the Problems) In order to achieve the above object, a semi-PC with a girder according to the present invention.
The method of manufacturing a floorboard is as follows: a half-PC floorboard forming form with a small beam, in which a small beam having a T-shaped or double T-shaped cross section and each molded portion of the lower half of the floor are connected to each other, is installed on a formwork installation gantry; The truss reinforcing part, which was previously formed in an arc shape, was vertically arranged on the beam forming part, and both ends of the truss were temporarily supported, and then the reaction force supported on the gantry in parallel with the gantry Depress the beam,
After pressing down the assembled truss reinforcing bar over the entire length of the reinforcing truss bar through the pressing beam mounted on the lower surface of the receiving beam in parallel with the small beam forming portion until the bar becomes horizontal, the state is maintained while maintaining this state. Concrete is cast into a formwork, and after the cast concrete exhibits a required strength, the pressing force on the assembled truss reinforcing bar by the pressing beam is released.

The apparatus for manufacturing a semi-PC floorboard with small beams according to the present invention includes a formwork gantry and a T-shaped or double T-shaped gantry installed on the gantry.
A beam-forming semi-PC floor plate forming form in which a beam forming section of a mold section and an underfloor section forming section are connected in series, and the formwork is installed at a right angle to the formwork above the formwork gantry. A reaction force receiving beam, a vertically expandable and contractible pressurizing device disposed between both ends of the reaction force receiving beam and the formwork installation gantry, and mounted on a lower surface of the reaction force receiving beam; It is composed of a press beam that extends right above the assembled truss reinforcing bar vertically installed in the small beam forming part and extends over substantially the center 1/3 thereof.

The pressurizing device has an upper end connected to the receiving beam via a fixing pin, and a lower end connected to the form setting gantry via a detachable pin, and is detachably attached to the gantry. It is good to be attached.

In addition, it is preferable that one pair of the pressurizing devices is disposed from a position rotated by 90 ° with respect to each other to prevent the device from overturning.

Further, a groove-shaped steel material for gripping the upper chord of the assembled truss reinforcing bar is disposed at a lower end of the pressing beam, so as to prevent lateral movement of the upper chord member when pressing the assembled truss reinforcing bar by the pressing beam. It is good to be constituted.

(Function) According to the method of manufacturing a semi-PC floor board with a small beam according to the present invention, as described above, the semi-PC with a small beam installed on the formwork installation groove gantry, as described above.
An assembling truss reinforcing bar which has been previously formed in an arc shape is vertically arranged on a small beam forming portion of the floor plate, and both ends of the truss reinforcing bar are temporarily supported, and then a counter support supported on the gantry in parallel with the gantry. When lowering the force receiving beam, pressure is applied over the entire length of the assembly truss reinforcing bar via a pressing beam mounted on the lower surface of the reaction force receiving beam in parallel with the small beam forming portion. The truss rebar is pressed evenly over its entire length, an average stress is introduced, and the pressurized portion is pressed only near the pressing point, as in the conventional method, so that the assembled truss rebar is locally bent. Therefore, no average stress is introduced into the rebar and no refraction occurs in the longitudinal direction of the rebar.

In this way, the concrete is cast in a state where the assembled truss reinforcing bar installed in the small beam molding portion is horizontally held under pressure, and after the cast concrete has developed the required strength,
By releasing the pressure applied to the assembled truss reinforcing bar by the pressing beam, a half-PC floor plate with small beams into which a required prestress is introduced by the restoring force of the assembled truss reinforcing bar is manufactured.

Further, the apparatus for manufacturing a semi-PC floorboard with a small beam according to the present invention is disposed in a direction perpendicular to the mold, on the upper part of a mold installation gantry on which the mold for molding a semi-PC floorboard with a small beam is installed. The reaction force receiving beam is supported via a vertically expandable and contractible pressing device disposed between both ends of the reaction force receiving beam, and is installed in a small beam forming portion of the formwork on the lower surface of the half force receiving beam. The above-mentioned manufacturing method is smoothly performed by mounting a press beam extending over substantially the center 1/3 of the assembled truss reinforcing bar.

(Example) Hereinafter, the present invention will be described with reference to an illustrated example.

(1) is a formwork for forming a half-PC floorboard with a small beam having a double T-shaped cross section, in which a small beam forming part (1a) and an underfloor half part forming part (1b) are connected in series. (2) is a formwork installation gantry on which the formwork (1) is installed, and (3) is a direction perpendicular to the formwork (1) above the gantry (2), that is, the beam width of the formwork (1). A vertical screw jack (4) constituting the pressurizing device is interposed at both ends of the receiving beam (3) and the gantry (2). The upper end of 4) is pivotally supported via a fixing pin (6) on the mounting seat (5) of the reaction force receiving beam (3), and the lower end is detachably mounted on the mounting seat (7) of the gantry (2). It is pivoted via a pin (8).

The pair of screw jacks (4) are 90
゜ It is arranged at a rotated position to prevent the receiving beam (3) from overturning.

On the lower surface of the reaction force receiving beam (3), the small beam forming portion (1
A pressing beam (9), which is located immediately above the assembled truss reinforcing bar installed as described later in a) and extends over substantially the center 1/3 of the reinforcing bar, is fixed.

In the figure, (10) is a bracket attached to the reaction force receiving beam (3), and (11) is a bolt for fastening the pressing beam (4) to the bracket (10).

A channel-shaped steel material (12) for gripping the upper chord of the assembled truss rebar is fixed to the lower surface of the pressing beam (9) via a bolt (13).

(14) in the figure is a lifting tool for the reaction force support beam (3).
(15) is an assembling truss reinforcing bar. The connecting hardware (15c) is attached to the upper chord material (15a) composed of double reinforcing bar and the lower chord material (15b) composed of single reinforcing bar at each required position.
Lattice streaks (15d) are connected between the connecting hardware (15c) of each of the upper and lower chord members (15a) (15b), and are previously cut in an arc shape.

The details of the assembling truss reinforcing bar (15) are described in detail in Japanese Utility Model Application No. 63-109546 (semi-Plexist joist slab using an assembling truss reinforcing bar) proposed by the present inventors. .

Then, the assembled truss reinforcing bar (15) is connected to the beam forming part (1a).
The truss rebar (15) is temporarily supported, and both ends of the truss reinforcing bar (15) are temporarily supported. Then, the screw jack (4) is shortened to lower the reaction force supporting beam (3), and the beam (3) is lowered. The upper chord material (15a) of the assembled truss reinforcing bar (9) is gripped by the grooved steel material (12) at the lower end surface of the pressing beam (9) mounted on the truss, and further via the screw jack (4). Reaction force receiving beam (3)
Truss bar (1)
When 5) is pressed, the truss reinforcing bar (15) is sequentially lowered from the arc-shaped top surface, and is uniformly pressed over the entire length of the truss reinforcing bar (15) to be in a horizontal state.

At this time, since the upper chord material of the truss reinforcing bar (15) is gripped by the grooved steel material (12), the truss reinforcing bar (15) is prevented from laterally buckling so as not to buckle horizontally due to the rolling force. Is done.

Thus, after the assembly truss reinforcing bar (15) is lowered in a horizontal state, the reinforcing bar (16) in the lower half of the floor is arranged while maintaining this state, and the concrete (17) is placed in the formwork (1).
After the cast concrete (17) exhibits the required strength, the screw jack (4) is extended to release the pressing force against the assembled truss reinforcing bar (15), and the pin (8) Then, the reaction force receiving beam (3) is removed together with the hydraulic jack (4), and the half PC floor plate with small beams as shown in FIG. 4 is removed from the formwork (1).

(Effects of the Invention) According to the method of the present invention, it is installed on a formwork installation gantry,
It is installed vertically on the girder molding part of the semi-PC floor plate with girder, and the both ends are temporarily supported. By applying pressure over the entire length of the assembled truss reinforcing bar to the lower surface of the reaction force receiving beam supported in parallel via a pressing beam mounted parallel to the small beam forming portion, the truss reinforcing bar is locally The average stress is introduced over the entire length of the assembled truss reinforcing bar without causing any refraction or bending in the longitudinal direction of the reinforcing bar. Pouring concrete while maintaining pressure,
After the cast concrete has the required strength, the pressing force on the assembled truss reinforcing bar by the pressing beam is released to manufacture a semi-PC floor plate with small beams into which the required prestress has been introduced.

The invention of claim 2 is that a reaction force receiving beam extending in a direction perpendicular to the formwork is disposed above a formwork gantry on which a formwork for forming a semi-PC floorboard with small beams is provided. A pressurizing device that is vertically expandable and contractible is interposed between the gantry, and on the lower surface of the reaction force receiving beam, just above the assembled truss reinforcing bar installed in the small beam molding portion of the formwork, A press beam extending over the center 1/3 is mounted to form a semi-PC floor semi-manufacturing formwork with small beams, so that the method of manufacturing a semi-PC floor plate with small beams described above can be smoothly performed. is there.

According to a third aspect of the present invention, an upper end of the pressurizing device is pivotally supported to the reaction force receiving beam via a fixing pin, and a lower end is connected to the form setting gantry via a detachable pin. The reaction force receiving beam provided with the pressing beam at the time of molding can be detached from the mold setting gantry together with the pressurizing device, thereby facilitating the work at the time of demolding.

According to a fourth aspect of the present invention, the two pressurizing devices are mounted between the form setting gantry and the reaction force receiving beam at a position rotated by 90 ° with respect to each other, thereby preventing the device from overturning. .

According to a fifth aspect of the present invention, the grooved steel material for gripping the upper chord of the assembled truss reinforcing bar is disposed at the lower end of the pressing beam, so that the truss reinforcing bar is horizontally seated when the assembled truss reinforcing bar is pressed down. This prevents sideways movement so as not to buckle.

[Brief description of the drawings]

1 to 4 are longitudinal sectional views showing the steps of one embodiment of the method of manufacturing a half-PC floorboard with small beams according to the present invention, FIG. 5 is a plan view of FIG. 1, FIG. 6 and FIG. 8 is a partial plan view and a partial side view of FIG. 1, respectively, a partial front view, FIG. 9 and FIG. 10 are longitudinal sectional views showing steps of the conventional method, and FIG. Partial perspective views, FIGS.12A, 12B, 12C and 12D
Fig. 13 is a longitudinal sectional view showing the process of rolling down the assembled truss reinforcing bar and placing concrete in the conventional construction method. Figs. 13 and 14 are explanatory views showing the pressurization of the assembled truss reinforcing bar in the conventional construction method and the deformation state due to the pressurization. is there. (1) ... Formwork for forming a semi-PC floor board with small beams, (1a) ... Small beam forming section, (1b) ... Underfloor half section forming section, (3) ... Reaction force receiving beam, (4) … Screws (6)… Fixing pin, (8)… Removable pin, (9)… Pressing beam, (12)… Groove steel, (15)… Assembly truss, 17) …… Concrete

Continued on the front page (72) Inventor Shinobu Fukudome 4-6-15 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Industries Co., Ltd. (72) Inventor Haruto Gomi 4-6-115 Sendagaya, Shibuya-ku, Tokyo Fujita Industries Co., Ltd. (72) Inventor Kazuhiko Sato 4-6-115 Sendagaya, Shibuya-ku, Tokyo Fujita Industries Co., Ltd. (72) Inventor Yoshiro Adachi 1-10-12 Nihonbashi-Horidome-cho, Chuo-ku, Tokyo Inside Chuo Built Industry Co., Ltd. 56) References JP-A-1-232002 (JP, A) JP-A-1-255507 (JP, A) JP-A-58-67408 (JP, A) JP-B-58-38286 (JP, B2)

Claims (5)

(57) [Claims] 1. A half-PC floor plate forming form with small beams, in which a T-shaped or double T-shaped cross-section beam and a lower half of the floor are connected to each other, are installed on a formwork installation gantry. In the beam forming part,
Assembled truss reinforcing rods that have been previously peeled off in an arc shape are vertically arranged to temporarily support both ends of the truss reinforcing rods, and then the reaction force receiving beam supported on the gantry in parallel with the gantry is lowered. After lowering the assembled truss reinforcing bar over the entire length of the reinforcing truss bar through the pressing beam mounted on the lower surface of the receiving beam in parallel with the small beam forming portion until the bar becomes horizontal, the mold is held while maintaining this state. A method of manufacturing a semi-PC floor panel, comprising: placing concrete in a frame; releasing the pressure exerted on the assembled truss reinforcing bar by the pressing beam; 2. A gantry on which a form is set, and a T installed on the gantry.
A beam-forming half-PC floorboard forming form in which a beam forming section having a mold or double T-shaped section and an underfloor section forming section are connected in series, and at the top of the form setting gantry in a direction perpendicular to the form. A reaction force receiving beam disposed, a vertically expandable and contractible pressurizing device disposed between both ends of the reaction force receiving beam and the formwork installation gantry,
It is mounted on the lower surface of the reaction force receiving beam, and approximately 1/3 of its center just above the assembled truss reinforcing bar installed vertically in the small beam forming part.
An apparatus for manufacturing a semi-PC floorboard with small beams, characterized by comprising a pressing beam extending over a distance. 3. The pressurizing device according to claim 1, wherein an upper end is connected to the reaction force receiving beam via a fixing pin, and a lower end is connected to the form setting gantry via a detachable pin. For manufacturing semi-PC floorboards with small beams. 4. The apparatus for manufacturing a semi-PC floor board with small beams according to claim 2, wherein said pair of pressurizing devices are mounted between said form setting gantry and a reaction force receiving beam at a position rotated by 90 ° from each other. 5. The apparatus according to claim 1, wherein a groove-shaped steel material for gripping an upper chord of the assembled truss reinforcing bar is disposed at a lower end of the pressing beam.