JP7336909B2 - Method for manufacturing precast concrete panels - Google Patents

Description

The present invention relates to, for example, a method for manufacturing precast concrete panels used for exteriors, and also relates to a method for manufacturing precast concrete panels suitable for precasting exteriors used in historic buildings and the like.

Conventionally, when preserving the exterior of a historic building, if the exterior consists of multiple pieces such as a retaining wall made of masonry, each piece is numbered, then the exterior is dismantled and disassembled, and attached to each piece. A method is taken to restore it to its original shape by assembling it based on the number.

However, with such a method, as the number of pieces increases, the numbering and management of each piece becomes more complicated, and there is a concern that the shape after restoration will easily change from that before restoration. On the other hand, even if the number of pieces is small, for example, one of the pieces was emphasized to have power and elegance, so it also had a structure that was easily damaged. If a huge relief plate is included, it becomes difficult to handle, and such a relief plate is recreated with a new material (GRC or FRP). The restoration cannot be utilized.

In view of these points, the inventors of the present invention have made various studies, and as a result, have obtained a technique that enables the restoration and utilization of the relief plate as described above. We also found that this technique can be widely applied not only to the preservation of historical buildings but also to precast concrete panels.

The present invention makes it possible to give a relief plate a force and elegance that could not be employed with conventional precast concrete panels due to its fragility, and restores historical buildings having such a relief plate. It aims at providing the manufacturing method of the precast concrete panel which also contributes to utilization.

In order to achieve the above object, a method for manufacturing a precast concrete panel according to the present invention includes a relief plate having a raised portion on the front side and a portion having a gap formed on the rear side, and a relief plate provided on the back side of the relief plate. A method for manufacturing a precast concrete panel having a reinforced concrete layer, wherein the relief plate is placed so that its front surface faces upward, and the upper side of the relief plate is filled with filler material in the gap. After forming a protective mortar layer on the relief plate, it is turned upside down, the reinforcing concrete layer is provided on the back side of the relief plate, and then the protective mortar layer is removed. is covered with a protective film, the gap is filled with a filling material from the front side of the protective film, and the front side is covered with a release film (Claim 1).

In the present invention, it is possible to give the relief plate a force and elegance that could not be adopted with the conventional precast concrete panel due to its fragility, and the restoration of the historical building having such a relief plate. A method for manufacturing a precast concrete panel that also contributes to utilization is obtained.

In other words, the precast concrete panel of the invention according to each claim of the present application has a three-dimensional shape with a gap in the rear, and the impact and elegance that cannot be adopted in the conventional precast concrete panel can be achieved. etc. can be given to the relief plate, which in turn contributes to the improvement of the grade of the building provided with this precast concrete panel.

In the method for manufacturing a precast concrete panel according to the first aspect of the invention, the reinforced concrete layer is provided on the back side of the relief plate with the front side of the relief plate facing downward and the back side facing upward. In addition, at this time, damage to the protuberances that protrude downward from the relief plate and receive the weight of the relief plate and the reinforced concrete layer, etc., can be prevented by the protective mortar layer covering it and the gap. It can be reliably prevented by packing clay.

In the method for manufacturing a precast concrete panel according to the first aspect of the invention, when forming the protective mortar layer, the protective film prevents the clay filling the gap from adhering to the relief plate, and the clay and the protective mortar layer are prevented from adhering to the relief plate. Since there is a release film between them, the clay does not interfere with the formation of the protective mortar layer, and the finally unnecessary protective mortar layer can be easily removed from the relief plate. Become.

1(A) and 1(B) are explanatory diagrams schematically showing the configuration of a step of extracting a relief plate in a method for manufacturing a precast concrete panel according to an embodiment of the present invention. FIG. (A) to (G) are explanatory diagrams schematically showing the steps of the method for manufacturing the precast concrete panel. (A) to (G) are explanatory diagrams schematically showing steps of installing anchor members in the method for manufacturing the precast concrete panel. (A) and (B) are explanatory views schematically showing a reinforced concrete forming step in the method for manufacturing the precast concrete panel. (A) to (G) are explanatory diagrams schematically showing steps of a modification of the method for manufacturing the precast concrete panel.

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2, a relief plate 1 (see FIG. 1(A)) made of, for example, a plurality of terracotta tiles used for the exterior of an existing building is collected, and the relief plate is 1 to manufacture a precast concrete panel P for exterior use (see FIG. 2(G)), and specifically, the following steps (A1) to (A8) are performed.

That is, as shown in FIG. 1(A), in an existing building, a relief plate 1 used for the exterior is integrated with an existing support layer (for example, an existing mortar mortar layer) 2 provided on the back side. It is held by the existing building framework (for example, reinforced concrete beams) (not shown).

(A1) In such an existing building, as shown in FIG. A frame 4 is constructed, and after a portion of the reinforcing frame 4 is embedded, the construction anchors 3 and the suspension steel frame 5 are fixed, and then the relief plate 1 cut with a wire saw or the like is lifted together with the suspension steel frame 5 and carried out. do. If the relief plate 1 is large, it may be cut into a plurality of pieces and carried out individually.

(A2) For the extracted relief plate 1, unnecessary portions other than the peripheral relief plate 1 are removed. Before this removal, the surface of the relief plate 1 is 3D scanned and the shape is converted into data just in case.

(A3) Cover the front surface of the relief plate 1 with a protective film 6 (clean the front surface if necessary before covering), and rearward the raised portion 7 of the relief plate 1 (downward in FIG. 2(A)). If there is a gap 7a, in order to prevent damage to the protuberance 7 in the post-process, fill the gap 7a from the front (front) side of the protective film 6 with a filling material 8, and then put a release film 9 on the front side. (a state in which the release film 9 covers the protective film 6 and the filling material 8) (see FIGS. 2A and 2B).

Here, it is conceivable to use, for example, a rubber-based elastic film for each of the protective film 6 and the demolding film 9 .

In addition, in order to prevent damage to the raised portion 7, the filling material 8 preferably has conformability and plasticity along the shape of the gap 7a, does not crack, and is difficult to dry and harden. can use clays such as oil clays.

(A4) A formwork 10 is installed around (laterally) the relief plate 1 placed with its front surface facing upward, and the relief plate 1, the existing support layer 2, and the reinforcing frame 4 are placed above and below the formwork. A reinforcing steel material 11 is installed to surround the outside (side) of the frame 10. With the formwork 10 supported from the outside by the reinforcing steel material 11, the surface of the relief plate 1 therein is filled with mortar (for example, vasa mortar, etc.). A protective mortar layer 12 is formed to protect the shape (see FIG. 2(C)).

Here, the reinforcing steel member 11 connects the horizontal surface forming portion 13a positioned on the lower side of the relief plate 1, the horizontal surface forming portion 13b positioned on the upper side, and the upper and lower horizontal surface forming portions 13a and 13b, and connects the relief plate 1 and the like. Specifically, the horizontal surface forming portions 13a and 13b are formed by assembling reinforcing steel members 11 (shaped steels 11a and 11b to be described later) in a grid shape. The side surface forming portion 13c is composed of a plurality of reinforcing steel members 11 so as to surround the relief plate 1 and the like. In the example of FIG. 2(C), in the horizontal surface forming portions 13a and 13b, the inner reinforcing steel material 11 in contact with the relief plate 1 and the like is H-shaped steel (or I-shaped steel) 11a, and the outer reinforcing steel material 11b is grooved. Steel is used, and the angle steel 11c is used for the side forming portion 13c. Part or all of the suspension steel frame 5 may be used as the reinforcing steel material 11 .

(A5) After curing the protective mortar layer 12, as shown in FIG. 2(D), the relief plate 1 is turned upside down (turned over) together with the reinforcing steel material 11 so that the protective mortar layer 12 faces downward, and then reinforced. A part of the steel material 11 is dismantled, and the reinforcing frame 4 and the existing support layer 2 on the back side are removed by scraping or the like until the relief plate 1 comes out (exposed) (see FIG. 2(E)).

(A6) An anchor material (for example, an anchor metal such as a shear connector) 14 for pouring concrete is installed on the exposed relief plate 1 from the back side (see FIG. 2(E)). In addition, in order to prevent the slag from leaking to the relief plate 1 side in the next process, a cement-based hard kneaded material is pushed into the gaps between the joints of the tiles constituting the relief plate 1 with a trowel. Fill in the cracked parts with epoxy resin adhesive.

Here, the installation of the anchor material 14 will be described in detail. For example, as shown in FIG. If the existing support layer 2 is filled in the grid (recessed portion) and there is no gap for new concrete to enter, a hole 15 is made in the existing support layer 2 that is filled in the grid, and the hole 15 A capsule 16 containing a solvent is inserted (see FIG. 3(B)), and an anchor material 14 such as a metal screw or a deformed steel rod is driven into the capsule 16 to break the capsule 16 and cause a chemical reaction of the solvent to release the anchor material. It is conceivable to adopt a chemical anchor (registered trademark) for fixing 14 (see FIG. 3(C)).

In addition, as shown in FIG. 3(D), when the squares of the back foot portion 1a of the tile are completely exposed or have large gaps, new concrete can be placed only in the squares. If the anchor material 14 can be expected to adhere to the tile, it is conceivable to insert and dispose the tip side of the anchor material 14 in the squares of the sole portion 1a of the tile as shown in FIG. 3(E). be done. If the existing support layer 2 remaining in the squares of the sole portion 1a has a fragile portion, the fragile portion and, if necessary, the periphery of the fragile portion so that the anchor material 14 can be inserted and arranged. can be removed as appropriate.

As shown in FIG. 3(F), when the sole leg portion 1a of the rib structure has a through-hole 1b for an anchor extending in the thickness direction thereof, an anchor material 14 bent at the tip side is inserted into the through-hole 1b. It is conceivable to fix it with an epoxy resin adhesive or the like.

In addition to the anchor material 14 arranged by the method of FIGS. 3(A) to 3(F), the anchor material 14 is directly screwed into thick portions such as intersections in the sole portion 1a having a substantially mesh-like rib structure. It is used together (see FIG. 3(G)).

It should be noted that it is essential to check the soundness of the relief plate 1 when screwing in the anchor material 14 described above. 1, and a strength confirmation test is performed using this piece.

(A7) A reinforced concrete layer (new prestressed concrete plate) 15 is formed so as to bury the anchor material 14 on the back side of the relief plate 1 (see FIG. 2(F)).

Here, as shown in FIGS. 4(A) and 4(B), the reinforcing bars 16 constituting the reinforced concrete layer 15 are combined into a mesh by welding and binding, and the highest point of the relief plate 1 is used as a reference. The plate thickness is set from the surface, and both the front and back sides are covered with a predetermined thickness t (for example, 30 mm). On the side of the relief plate 1, for example, a plastic donut spacer 17 or the like is incorporated in the lower end reinforcing bar 16 and placed directly on the relief plate 1. - 特許庁

(A8) After curing the reinforcing concrete layer 15, as shown in FIG. 2(G), the relief plate 1 is turned upside down (upside down) together with the reinforcing steel material 11 so that the protective mortar layer 12 faces upward, and the protective mortar layer is removed. 12. Reinforcing steel material 11, formwork 10 and the like are removed. Above, the precast concrete panel P is completed.

Next, installation of the precast concrete panel P will be described. This installation is performed, for example, by performing the following steps (A9) to (A11).

(A9) For example, the precast concrete panel P completed in a factory or the like is carried into the site.

(A10) Attach the precast concrete panel P to a steel frame beam (not shown. A concrete beam or the like may be used). For this attachment, for example, both the precast concrete panel P and the steel frame beam may be provided with metal fittings, and the metal fittings may be fixed to each other with bolts or the like.

(A11) When the relief plate 1 is large and the relief plate 1 is to be restored by arranging a plurality of precast concrete panels P side by side, the joints between the panels P are restored and repaired. Above, installation of the precast concrete panel P is completed.

The precast concrete panel P completed by the above steps (A1) to (A8) is, as shown in FIG. and a reinforced concrete layer 15 provided on the back side of the relief plate 1, and the raised portion 7 presenting a three-dimensional shape having a portion with a gap 7a behind the relief plate 1 is adopted in the conventional precast concrete panel. The relief plate 1 can be endowed with power, gracefulness, etc., which has been impossible, and this contributes to the improvement of the grade of the building provided with this precast concrete panel P.

Further, in the method for manufacturing the precast concrete panel P of this example, in the step (A5), the front surface of the relief plate 1 is turned downward and the back surface is turned upward, and in the step (A7), the relief plate 1 is placed on the back side. Since the reinforced concrete layer 15 is provided, the reinforced concrete layer 15 can be easily provided by casting or the like, and at this time, it projects downward from the relief plate 1 and receives the weight of the relief plate 1, the reinforced concrete layer 15, and the like. The breakage of the protuberance 7 can be reliably prevented by the protective mortar layer 15 covering it and the filling material 8 filled in the gap 7a. In addition, the manufacturing method of the precast concrete panel P of this example contributes to the restoration utilization of the historical building having the relief plate 1 with the gap 7a as described above.

Furthermore, in the manufacturing method of the precast concrete panel P of this example, when the protective mortar layer 12 is formed in the step (A4), the filler material 8 filling the gap 7a adheres to the relief plate 1. In addition, since the release film 9 exists between the filling material 8 and the protective mortar layer 12, the filling material 8 does not hinder the formation of the protective mortar layer 12, and the final The protective mortar layer 12, which is practically unnecessary, can be easily removed from the relief plate 1 in step (A8).

It goes without saying that the present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the gist of the present invention. For example, the following modifications can be given.

In the above step (A1), the relief plate 1, the existing support layer 2, the reinforcing frame 4 and the suspension steel frame 5 are carried out in an integrated state. If the strength is sufficient, the relief plate 1 and the existing support layer 2 may be fixed to the suspension steel frame 5 by an appropriate means without constructing the reinforcing frame 4, and then carried out. In addition, the post-installed anchors 3 and the reinforcing frame 4 may be installed and constructed in a state in which part or all of the existing support layer 2 is removed. The post-installed anchors 3 and the reinforcing frame 4 may be installed and constructed on the back side of the plate 1 .

In the above step (A3), as shown in FIG. 2B, the filling material 8 is filled only in the gap 7a. It may be packed in such a way as to be leveled (flattened).

In the above steps (A1) to (A8), the precast concrete panel P is manufactured using the relief plate 1 collected from the existing building. may be manufactured. Specifically, the following steps (B1) to (B8) are performed.

(B1) As shown in FIG. 5(A), the level adjusting material 21 is placed on the horizontal surface forming portion 13a (see FIG. 2(C)) constituted by the reinforcing steel material 11, and the periphery thereof is surrounded by the formwork 10. A reinforcing steel material 11 for supporting the formwork 10 is installed outside the formwork 10 as required.

(B2) As shown in FIG. 5(B), a plurality of tiles (for example, terracotta tiles) T constituting the relief plate 1 are laid on the level adjusting material 21 . In addition, the tile T is placed on the level adjustment member 21 so that the front surface thereof faces upward. Considering the labor involved in removing the level adjustment material 21 in a post-process, it is preferable that the tile T and the level adjustment material 21 are not integrated. The both T and 21 may be temporarily fixed by using, for example.

Here, the level adjustment material 21 is for adjusting the level of each tile T so that the plurality of laid tiles T form the desired relief plate 1. For example, a sand mold, a plastic plate, a block, or the like. , can be made of appropriate materials and members.

(B3) As in the above step (A3), the front surface of the relief plate 1 composed of all the tiles T is covered with the protective film 6 (if necessary, the front surface is cleaned before covering), and the relief plate 1 is If there is a gap 7a behind (lower in FIG. 5(B)) in the raised portion 7, the gap 7a is provided from the front (front) side of the protective film 6 in order to prevent damage to the raised portion 7 in the post-process. The stuffing material 8 is stuffed, and the front side is covered with the mold-removing film 9 (the mold-removing film 9 covers the protective film 6 and the stuffing material 8) (FIGS. 5B and 5C )reference)

(B4) As in the above step (A4), each tile T and the level adjustment member 21 are surrounded by reinforcing steel members 11 from above and below and outside (sides) of the formwork 10, and the formwork 10 is supported from the outside by the reinforcement steel members 11. In this state, the surface of the relief plate 1 therein is filled with mortar (for example, mortar or the like) to form a protective mortar layer 12 for protecting the surface shape (see FIG. 5(C)).

(B5) After curing the protective mortar layer 12, as shown in FIG. 5(D), the relief plate 1 is turned upside down (turned over) together with the reinforcing steel member 11 so that the protective mortar layer 12 faces downward, and then reinforced. The steel material 11 is partially dismantled, and the level adjusting material 21 on the back side of the relief plate 1 is removed (see FIG. 5(E)).

(B6) An anchor material (for example, an anchor metal such as a shear connector) 14 for concrete driving is installed on the exposed relief plate 1 from the rear side thereof. In addition, in order to prevent the slag from leaking to the relief plate 1 side in the next step, a hardened cement-based material is pushed into the gap between the joints of the tiles T constituting the relief plate 1 with a trowel (Fig. 5 ( E)).

(B7) As in step (A7) above, a reinforced concrete layer (new prestressed concrete plate) 15 is formed on the back side of the relief plate 1 so as to bury the anchor material 14 (see FIG. 5(F)).

(B8) As in the above step (A8), after curing the reinforced concrete layer 15, as shown in FIG. Then, the protective mortar layer 12, the reinforcing steel material 11, the formwork 10 and the like are removed. Above, the precast concrete panel P is completed.

In addition, it cannot be overemphasized that you may combine suitably the modification mentioned in this specification.

REFERENCE SIGNS LIST 1 relief plate 1a back leg 1b through hole 2 existing support layer 3 post-construction anchor 4 reinforcing frame 5 suspension steel frame 6 protective film 7 raised portion 7a gap 8 filling material 9 stripping film 10 formwork 11 reinforcing steel material 11a H-shaped steel 11b Channel steel 11c Angle steel 12 Protective mortar layer 13a Horizontal surface forming part 13b Horizontal surface forming part 13c Side forming part 14 Anchor material 15 Reinforcing concrete layer 16 Reinforcement bar 21 Level adjustment material P Precast concrete panel T Tile

Claims (1)

a relief plate having a raised portion on the front side with a portion having a gap in the rear;
A method for manufacturing a precast concrete panel comprising a reinforced concrete layer provided on the back side of the relief plate, comprising:
The relief plate is placed so that its front surface faces upward, and a protective mortar layer is formed on the upper side of the relief plate in a state in which the gap is filled with a filler material. providing said reinforced concrete layer on the side and then removing said protective mortar layer,
The protective mortar layer is formed by covering the front surface of the relief plate with a protective film, filling the gap from the front side of the protective film with a filling material, and covering the front side with a release film. A method for manufacturing precast concrete panels.

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