JP2743276B2 - Apparatus and method for producing precast concrete - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for producing precast concrete and a method for producing a plurality of precast concretes to be connected to each other using the apparatus.

[Related Art] In recent years, when constructing a reinforced concrete structure, a method of manufacturing a large number of precast concrete members having predetermined dimensions in a factory in advance and sequentially connecting and assembling these members at a construction site. Have been widely adopted in response to requests for shortening the construction period.

A plurality of reinforcing rods each having a simple substantially cylindrical rod shape are buried in the interior of the conventional precast concrete, and an end of each reinforcing rod projects from the concrete portion.

When connecting the above-mentioned conventional precast concrete, the ends of the corresponding reinforcing bars of the two precast concretes to be connected are connected via joints. This joint has a cylindrical shape, and the inner diameter of the through hole provided along the axis is larger than the outer diameter of the reinforcing bar. Each end of the reinforcing bar to be connected is inserted into the through hole of this joint from both sides thereof, and mortar is further filled therein and solidified to connect the reinforcing bars. After that, the entire connecting portion of the two precast concretes is surrounded by a mold, and mortar is filled in the inside thereof to connect the two precast concretes.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional precast concrete, since the mounting position of the reinforcing bar is very inaccurate, in order to cover them, the inside diameter of the through-hole of the joint is made considerably large. Therefore, the joint itself had to be large. However, when the joint is made large in this way, there has been a problem that when the outside of the reinforcing bar is connected with concrete, the cover thickness of the concrete may not be sufficiently secured.

The present invention has been made in view of the above-described problems of the related art, and has as its object to interconnect with a precast concrete manufacturing device capable of arranging reinforcing bars at accurate positions. To provide a method for producing a plurality of precast concretes which is easy to use.

[Means for Solving the Problems] The present invention has been made to achieve the above object,
The gist of the first invention is that (a) a box is formed having a cavity into which concrete is poured and a pair of end plates facing each other. A hole is formed, the through hole has a diameter larger than the circumcircle of the screw reinforcing bar, and a formwork including a tapered hole that gradually decreases in diameter toward the cavity, and (b) an end of the screw reinforcing bar. In addition to having a screw hole for screwing, the outer periphery of the leading end forms a tapered portion whose diameter gradually decreases toward the tip at substantially the same taper angle as the tapered hole, and this tapered portion engages with and disengages from the tapered hole of the mold. And a possible positioning member.

The gist of the second invention is to prepare a plurality of the manufacturing apparatuses according to claim 1 and arrange the molds in a line, insert the screw rebars into through holes of both end plates in each mold, and The above-mentioned positioning member is screwed into the end of each of the projecting screw rebars, and the screw rebars attached to the formwork adjacent to each other and arranged substantially in a straight line form a cylindrical shape in which the screw rebars are screwed to the ends of these screw rebars. Connected via joints, tighten the positioning members, engage the tapered portions of the positioning members with the tapered holes of the through holes of each end plate of the mold, and maintain each of the molds while maintaining this state. The concrete casting method is characterized in that concrete is poured into the hollow portion of the mold and cured, and after the curing, the joints connecting the formwork are removed and the formwork is removed.

[Operation] In the present invention, a threaded reinforcing bar is inserted into the through-holes of both end plates of the formwork, and positioning members are screwed into each end of the threaded bar projecting from the end plate, and each of the positioning members is tightened. Is engaged with the tapered hole of the through hole of each end plate. By doing so, each screw rebar can be arranged at the correct position on the formwork, so that a precast concrete with the screw rebar arranged at the correct position can be obtained.

Also, when manufacturing precast concrete to be connected multiple, before casting concrete in each formwork,
The screw rebars that penetrate the adjacent formwork are connected in advance with joints, and concrete is poured into each formwork to obtain a plurality of precast concrete. In this way, the precast concrete can be smoothly connected without any trouble without causing a problem that the pitch of the screw reinforcing bars to be connected does not match.

And in each precast concrete, since the screw rebar is placed in the correct position and the correct posture,
It can be connected using a joint that is screwed with these.
As a result, the joints need only be of the minimum required size, so that the concrete covering thickness at the connecting portion can be sufficiently obtained.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.

1 and 2 show a front view and a right side view of the precast concrete 1, respectively.

This precast concrete 1 is composed of a square pillar-shaped concrete portion 2 and 16 screw reinforcing bars 3 buried in the inside thereof in a penetrating state. The screw reinforcing bar 3 has a rod shape, and a spiral convex portion 3a (see FIG. 6 for details) is formed on an outer peripheral surface thereof. The threaded reinforcing bars 3 are precisely arranged at equal intervals on the peripheral edge of the concrete portion 2 and along the longitudinal axis thereof.

3 to 6 show the precast concrete 1
1 shows a manufacturing apparatus for precast concrete used in manufacturing a precast concrete. This manufacturing equipment is
It has. The formwork 10 includes a frame body 11 having a U-shaped vertical cross section that closes three surfaces along the longitudinal direction, and an end plate 12 fixed to both ends of the frame body 11 via bolts and nuts (not shown). , 12. The frame body 11 and both end plates 12,
The inside surrounded by 12 is a cavity 14 into which concrete is poured, and the upper part is open. The manufacturing apparatus further includes a positioning member 13 for positioning the screw reinforcing bar 3.

In each of the end plates 12, a portion corresponding to the peripheral portion of the hollow portion 14 has an axis positioned exactly perpendicular to the end plate 12.
Sixteen through holes 15 are provided at exactly equal intervals. The axes of the through holes 15 facing each other on both end plates 12 are located on a straight line, and are parallel to the axis of the cavity 14. As shown in FIG.
A straight hole 15a having a diameter slightly larger than the outer diameter of the screw reinforcing bar 3 is formed. The outside of the straight hole 15a is gradually reduced in diameter toward the cavity 14 and a tapered hole 15b connected to the straight hole 15a. It has become.

The positioning member 13 can be engaged with and disengaged from the tapered hole 15b. As shown in FIG. 6, the positioning member 13 has a base outer periphery which is an engaging portion for a tool such as a pipe reinch.
13a, the cross-sectional shape of which is a hexagon like a nut, and the outer periphery of the tip is a tapered portion 13b, the taper angle of which is substantially the same as the taper angle of the tapered hole 15b. Has been. At the center of the positioning member 13, a screw hole 13c is provided along the axis thereof. On the inner peripheral surface of the screw hole 13c, a spiral convex portion 3a of the screw reinforcing bar 3 is provided.
Is formed with a spiral groove.

The precast concrete 1 is manufactured by using the above manufacturing apparatus as follows.

First, end plates 12 and 12 are attached to both ends of the frame body 11, respectively, to assemble a box whose upper part is opened. Next, end plate 1
The threaded rebars 3 are inserted into the through holes 15, 15 that are opposed to each other at 2 and 12, and both ends of each threaded rebar 3 are projected outward from the end plates 12. Then, a positioning member 13 is screwed into both ends of the screw reinforcing bar 3 protruding from each end plate 12 with its tapered portion 13b facing the hollow portion 14, and the tapered portion of each positioning member 13 is screwed.
13b is brought into close contact with the tapered hole 15b of the end plate 12 to engage. In this way, each screw reinforcing bar 3 is arranged at a desired correct position, its axis is parallel to the axis of the cavity 14, and the end of each screw reinforcing bar 3 is attached to each end plate 12. It will be arranged so as to be orthogonal to this.

Formwork to which 16 screw reinforcing bars 3 are attached as described above
Concrete is poured into the hollow portion 14 of 10 and after a predetermined curing period has elapsed, the positioning member 13 is removed from each screw reinforcing bar 3, each end plate 12, 12 is further removed, and the mold is released from the frame body 11. The above-mentioned precast concrete 1 shown in FIGS. 1 and 2 is completed. As described above, the precast concrete 1 manufactured as described above has the threaded reinforcing bar 3 arranged at the correct position, and its end protrudes vertically from the end face of the concrete portion 2.

Next, when a plurality of the precast concretes 1 are connected along the longitudinal direction to construct a tall column, a plurality of precast concretes 1 used for this are used.
Is produced as follows.

The required number of the above-mentioned precast concrete forms 10 are prepared in advance for the columns to be constructed, the frame body 11 and both end plates 12 and 12 are respectively assembled, and the threaded reinforcing bar 3 is inserted into each through-hole 15 and both ends thereof are formed. The positioning members 13 are screwed into the respective parts. However, at this point, for one mold 10, the tapered portion 13b of the positioning member 13 is tightly engaged with the tapered hole 15b of each end plate 12 to fix each screw reinforcing bar 3 as described above. In the meantime, for each of the other molds 10, although each screw reinforcing bar 3 is inserted, each positioning member
13 is loosely screwed, and the tapered portion 13b is not tightly engaged with the tapered hole 15b of each end plate 12.

On the basis of the one formwork 10, another formwork 10 is connected to this formwork 10 via the screw bar 3, and the connected formwork 10
Then, the other molds 10 are connected to each other, and so on.

For example, if the mold 10 located on the leftmost side in FIG. 7 is the reference mold, the other molds 10 are aligned on the left and right in a straight line. Then, the joint 20 is screwed into the screw reinforcing bar 3 protruding from the right end plate 12 of the formwork 10 as a reference to the back. The joint 20 has a cylindrical shape, and has a spiral groove (not shown) formed on the inner peripheral surface thereof to be screwed with the spiral convex portion 3a of the screw reinforcing bar 3.

Next, each of the joints 20 is screwed to an end of each screw reinforcing bar 3 protruding from the left end plate 12 in another formwork 10 arranged immediately to the right of the reference formwork 10 and has a required length. The screw threads are screwed into each other, and the corresponding threaded reinforcing bars 3 of these two molds 10, 10 are connected. After that, the positioning members screwed to both ends of each screw reinforcing bar 3 of the other formwork 10 described above.
13 by tightening the tapered portion 13b and each tapered hole 15b of each end plate 12 in close contact.
Are fixed.

By sequentially repeating the above-described procedure, as shown in FIG. 7, the threaded reinforcing bars 3 are fixed to all the prepared formwork 10, and the threaded reinforcing bars 3, 3,...
0, so that each mold 10 is connected.

Next, concrete is poured into the cavity 14 of each of the molds 10 and cured for a predetermined time.

After the above curing, the joint 20 is removed from each screw reinforcing bar 3,
Each mold 10 is separated from each other. After being separated into the respective molds 10, the precast concrete 1 necessary for column construction can be obtained by releasing the molds 10 from the respective molds 10 in the same procedure as described above. Then, when constructing the pillar at the construction site, if the connection order at the time of the above-mentioned production is reproduced, the pitch of the spiral convex portion 3a of the screw reinforcing bar 3 to be connected correctly matches. As shown, the precast concrete 1 can be smoothly connected by the joint 20 without any trouble.

As shown in FIG. 9, the entire connection portion A of each precast concrete 1 connected through the joint 20 is surrounded by a wooden frame 30, and mortar is injected from the injection port 31 to cure the precast concrete 1.
When 30 is removed, the pillar 40 as shown in FIG. 10 is completed.

In each precast concrete 1, since the screw reinforcing bar 3 is arranged in a correct position at a correct position,
The joint 20 enables connection by screwing, and the joint 20 can be reduced to a necessary minimum size. As a result, the cover thickness of the concrete at the connection portion A can be sufficiently increased.

The present invention is not limited to the above embodiments, and various modes can be adopted.

For example, it goes without saying that the reinforcing bars may be arranged so as to be wound around the screw bars 3 in the above-described embodiment.

Further, in the above embodiment, the columns are constructed using the precast concrete 1, but it is needless to say that the columns may be used when constructing the beams.

[Effects of the Invention] As described above, the present invention has the following excellent effects.

That is, the end plate of the form includes a tapered hole through hole through which the screw reinforcing bar is inserted, and the tapered portion of the positioning member for the screw reinforcing bar can be disengaged from the tapered hole,
Further, since the threaded rebar is screwed into the positioning member, an excellent effect is achieved that the threaded rebar can be arranged at the correct position in the correct posture in the formwork.

Therefore, the precast concrete manufactured with the precast concrete form has an excellent effect that the screw reinforcing bar is arranged at a correct position and in a correct posture.

Further, in the case of manufacturing the above-mentioned precast concrete to be connected to a plurality of pieces, since the screw reinforcing bars penetrating the adjacent formwork are connected via a joint before the concrete is poured, the concrete When connecting precast concrete manufactured by casting, an excellent effect is achieved in that the precast concrete can be connected smoothly without hindrance if it is connected in the order of the above temporary assembly. You.

Further, there is also an effect that the covering thickness of the concrete can be sufficiently obtained at the connecting portion.

[Brief description of the drawings]

1 to 10 show one embodiment of the present invention. FIG. 1 is a front view of precast concrete, FIG. 2 is a right side view of the same, and FIG. 3 is a mold for precast concrete. Front view of the frame, FIG. 4 is the right side view, FIG. 5 is the same plan view, FIG. 6 is an enlarged sectional view taken along the line VI-VI of FIG. 4, and FIG. FIG. 8 to FIG. 10 are front views showing construction steps when columns are constructed using this precast concrete. 1 ... precast concrete, 2 ... concrete part,
3 ... screw reinforcing bar, 3a ... helical convex, 10 ... formwork for precast concrete, 12 ... end plate, 13 ... positioning member, 13b ...
Tapered part, 13c screw hole, 14 hollow part, through hole 15, 15b ...
Taper hole, 20 ... Joint.

Claims (2)

(57) [Claims] (1) A box having a hollow portion into which concrete is poured and a pair of end plates facing each other is formed into a box shape. The through hole has a diameter larger than the circumscribed circle of the screw reinforcing bar, and includes a formwork including a tapered hole that gradually decreases in diameter toward the cavity, and (b) screwed into an end of the screw reinforcing bar. With a screw hole, the outer periphery of the tip portion forms a tapered portion whose diameter gradually decreases toward the tip at substantially the same taper angle as the tapered hole, and the tapered portion is engaged with and disengaged from the tapered hole of the mold. An apparatus for producing precast concrete, comprising: a member; 2. A plurality of the manufacturing apparatuses according to claim 1 are prepared, the molds are arranged in a line, the screw rebars are inserted into through holes of both end plates in each mold, and each projecting from the end plate. The positioning member is screwed to the end of the screw rebar, and the screw rebars attached to the formwork adjacent to each other and arranged substantially in a straight line are connected via a cylindrical joint that is screwed to the end of the screw rebar. And tightening the positioning members to engage the tapered portions of the positioning members with the tapered holes of the through-holes of the end plates of the mold, respectively. A method for producing precast concrete, characterized in that concrete is poured into the concrete and cured, and after the curing, the joints connecting the respective forms are removed and the respective forms are removed.