JP7455931B1 - Precast board manufacturing method and precast board - Google Patents

Abstract

[Problem] To provide a precast plate etc. that reduces the labor required for preparation and construction and contributes to stabilizing the quality of joints. [Solution] A precast plate 1 is placed in a concrete joint. The precast plate 1 comprises a flat concrete body 2 with recesses 21 formed on the front and back surfaces, reinforcing members 3 for preventing cracks that are embedded in the body 2 and arranged in the in-plane direction of the body 2, and hanging members 4 provided on the end faces of the body 2. In addition, holes 5 for inserting reinforcing bars are provided in the body 2. [Selected Figure] Figure 1

Description

TECHNICAL FIELD The present invention relates to a precast plate and the like placed at a concrete joint.

When pouring fresh concrete on large cross-sections of foundations, walls, etc., the joints are often constructed with lath wire mesh, etc. When pouring concrete on beams, air fences, etc. are used to connect the concrete. It is common to perform processing.

Patent Document 1 also describes a construction method in which a partition material made of a lath mesh installed inside a concrete frame and coated with a cement-based adhesive is placed in the joint, and concrete is poured sequentially on both sides of the partition material.

Patent No. 6852993

When lath netting or air fences are used, construction is time consuming and the process is burdensome. Additionally, air fences require work by special professionals, and additional labor is required to remove slag after the fence is removed, which adds to the cost burden. It is also necessary to remove weak areas on the concrete surface at joints.

The invention described in Patent Document 1 prevents the occurrence of slag leakage and reduces the need for slag treatment, but due to the use of cement-based adhesives, confirmation by an examining body is required for each property depending on the structure of the building. This increases the preparation time. Furthermore, the application of cement adhesive requires work by professionals, which increases labor and requires coordination between different occupations.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a precast board etc. that reduces preparation and construction time and contributes to quality stability of the spliced joint.

A first invention to achieve the above-mentioned object is a method for manufacturing a precast board to be placed at a concrete joint, wherein the precast board is made of concrete and has recesses formed on its front and back surfaces. It comprises a flat plate-shaped main body, a reinforcing material for crack prevention embedded in the main body and arranged in the in-plane direction of the main body, and a hanging part provided on an end surface of the main body, through which a reinforcing bar is inserted. an insertion part is provided in the main body for the purpose of the present invention, and when producing the precast board, concrete for the main body is poured into the formwork with the net-shaped reinforcing material placed on the bottom of the formwork; This method of manufacturing a precast board is characterized in that the concrete is passed around to the bottom side of the formwork through the mesh of the reinforcing material, and the reinforcing material is lifted from the bottom surface of the formwork .
A second invention is a precast board placed in a joint of concrete, which includes a flat plate-like main body made of concrete with recesses formed on the front and back surfaces, and a precast board that is embedded in the main body and has a surface of the main body. A mechanical joint for attaching reinforcing bars is provided on the main body, and the mechanical joint includes a reinforcing material for preventing cracks arranged inward and a hanging part provided on an end surface of the main body , and the mechanical joint has a cylindrical shape. The reinforcing bars on both sides of the precast plate are inserted from both ends of the mechanical joint in the axial direction, and one end of the mechanical joint is connected to one surface of the main body. The precast plate is a precast plate that protrudes from the main body and has the other end aligned with the other surface of the main body .

The precast board of the present invention is manufactured in advance by forming recesses on the front and back surfaces of the main body and embedding reinforcing material therein. Placing this precast board at the joint of concrete eliminates the need for specialist work such as applying cement adhesive, reducing preparation and construction time, leading to reduced labor and improved productivity. Furthermore, the outflow of slag from the spliced joint is significantly reduced, and the quality of the spliced joint can be stabilized. In addition, the concave portion of the main body improves adhesion to concrete, and the reinforcing material helps prevent the precast board from cracking due to vibrations, etc. Furthermore, the main body is provided with a reinforcing bar insertion portion and a mechanical joint, making it easier to arrange the reinforcing bars.

It is desirable that the reinforcing material is a net material made of alkali-resistant glass fiber.
Thereby, cracking of the precast board due to vibration etc. can be suitably suppressed.

It is desirable that the insertion portion is a hole that penetrates the main body in the thickness direction. Further, the insertion portion may be a groove provided in an end surface of the main body.
If a hole is provided as a reinforcing bar insertion part, the reinforcing bar penetrating the splicing part can be easily arranged. On the other hand, if a groove is provided, reinforcing bars can be easily placed on the end face of the main body.

It is preferable that the hanging part has a bolt hole on its inner surface for use in attaching a hanging tool, and includes an insert embedded in the main body so as not to protrude from an end surface of the main body.
This makes it possible to attach a hanger to the insert and transport the precast board by hanging it, and the insert does not become an obstacle when temporarily placing the precast board.

According to the present invention, it is possible to provide a precast board or the like that reduces preparation and construction time and contributes to stable quality of the joint.

A diagram showing a precast board 1. FIG. FIG. 3 is a diagram illustrating a method for manufacturing a precast board 1. FIG. 6 is a diagram showing a hanging tool 6; The figure which shows the state where the hanging tool 6 was attached to the precast board 1. A diagram showing a precast board 1a.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing a precast board 1 according to an embodiment of the present invention. As shown in FIG. 1, a precast board 1 includes a main body 2, a reinforcing material 3, a hanging part 4, and the like. The precast board 1 is placed in a formwork F for pouring concrete for a foundation and a foundation beam at a location corresponding to a concrete joint, with the board surface facing vertically.

The main body 2 is a flat member made of concrete. The concrete of the main body 2 has, for example, the same compressive strength as the concrete of the foundation and the foundation beam, but the present invention is not limited to this.

In addition, the main body 2 is formed with recesses 21 on both the front and back surfaces, which are in contact with the concrete of the foundation and the foundation beam. This recess 21 improves the adhesion between the concrete poured on site and the main body 2. The front and back surfaces of the main body 2 correspond to the left and right surfaces of the main body 2 in FIG.

The reinforcing material 3 is embedded in the concrete of the main body 2. The reinforcing material 3 is a net material disposed in the in-plane direction of the precast board 1, and prevents the concrete of the main body 2 from cracking due to vibration or the like. Note that the in-plane direction of the main body 2 is a direction parallel to the front and back surfaces of the main body 2.

In this embodiment, the reinforcing material 3 is made of alkali-resistant glass fiber, for example, Hypernet (registered trademark) can be used. Hypernet (registered trademark) is a net material made of unidirectional glass fibers with a large amount of fibers arranged in the longitudinal direction, and has a lattice spacing and cross-sectional shape that has high reinforcement efficiency and can effectively suppress cracks. . However, the reinforcing material 3 is not limited to this, and for example, a normal glass fiber net can be used instead of Hyper Net (registered trademark).

The hanging part 4 is a part used for suspending and transporting the precast board 1, and is provided on the end surface that becomes the upper surface when the precast board 1 is placed at the joining part. FIG. 2 shows a cross section of the hanging portion 4 in the in-plane direction of the precast board 1. As shown in FIG. As shown in FIG. 2, the hanging portion 4 includes an insert 41 and an anchor 42.

The insert 41 is a cylindrical member that has a bolt hole on its inner surface to be used for attaching a hanging tool 6 (see FIG. 4), which will be described later. It is buried in the main body 2.

The anchor 42 is screwed into the other end of the insert 41 and embedded in the main body 2 to fix the insert 41 to the main body 2. In the example of FIG. 2, the shape of the anchor 42 is a J-shape, but the shape is not limited to this, and may be a Y-shape or the like.

As shown in FIG. 1, a plurality of holes 5 are formed in the precast board 1 as insertion portions for inserting the reinforcing bars (beam main bars) of the foundation beam. The hole 5 is provided so as to penetrate the plate-shaped main body 2 in the thickness direction. The position and dimensions of each hole 5 are determined in advance based on the reinforcement plan of the foundation beam, and each hole 5 is formed in the main body 2 at a predetermined position and dimension when the precast board 1 is manufactured.

When manufacturing the precast board 1, a material 91 for forming the holes 5 is fixed inside a box-shaped steel formwork 9 shown in FIG. 3(a). This material 91 has a cylindrical shape, and the material 91 having a diameter corresponding to the size of the hole 5 is arranged in accordance with the position of the hole 5. In addition, inside the steel formwork 9, the above-mentioned hanging portions 4 and the like are also fixed in advance at predetermined positions.

Furthermore, a concrete hardening retardant (not shown) is applied to the bottom surface of the steel formwork 9, and the reinforcing material 3 is placed inside the steel formwork 9. Regarding the reinforcing material 3, for example, a plurality of strip-shaped reinforcing materials 3 are arranged so that no gaps are formed. The reinforcing material 3 has flexibility and can be stored in a rolled state and used by unfolding it.

Thereafter, as shown in FIG. 3(b), the concrete Con of the main body 2 is poured into the steel formwork 9. The concrete Con poured into the steel formwork 9 wraps around the bottom surface of the steel formwork 9 through the mesh of the reinforcing material 3, and the reinforcing material 3 rises from the bottom surface of the steel formwork 9.

After the concrete Con of the main body 2 is cast, a curing retarder similar to that described above is sprinkled on the top surface of the concrete Con. Then, when the cast concrete Con hardens and develops at least the strength required for demolding, the main body 2 is demolded from the steel formwork 9. The steel formwork 9 can be used as a formwork when manufacturing other precast boards 1.

After the main body 2 is removed from the steel formwork 9, the concrete Con in the unhardened portion of the main body 2 caused by the curing retardant is washed away, and the aggregate falls off. Then, the portion where the aggregate was present becomes a recess 21, and the recess 21 is formed on the front and back surfaces of the main body 2. Through the above steps, the precast board 1 is manufactured. Note that the holes 5 can be formed by removing the material 91 at an appropriate time, but the holes 5 can also be formed by removing the core from the main body 2 after the concrete Con has hardened, and in this case, the material 91 is not required. It is.

The completed precast boards 1 are temporarily stored in a factory site or the like, loaded onto a truck, and transported to the site. By embedding the reinforcing material 3 in the main body 2, the main body 2 is prevented from cracking due to vibration or the like when the precast board 1 is temporarily placed or transported. Note that if there is sufficient space on the site, the precast board 1 may be manufactured on-site (on-site). In this case, the concrete for the main body 2 can be poured directly with a chute by moving the ready-mixed concrete truck close to the steel formwork 9, if possible due to the vehicle arrangement.

When installing the precast board 1 on site, a hanging tool 6 shown in FIG. 4 is attached to the hanging part 4. The hanging tool 6 is a pair of L-shaped steel plates 61 having a vertical plate 611 and a horizontal plate 612, and the vertical plates 611 are stacked on top of each other and fixed by welding. Below these steel plates 61, a pair of parallel plates 62 are provided so as to straddle the horizontal plates 612 of both steel plates 61. A bolt hole (not shown) is formed in one of the plate members 62, and a bolt 63 is screwed into the bolt hole.

A hole 613 for passing a wire or the like is provided at a corresponding position on the vertical plate 611 of each steel plate 61. Further, holes 614 for passing bolts are provided in the horizontal plate 612 of each steel plate 61.

FIG. 5 is a diagram showing a state in which the hanging tool 6 is attached to the precast board 1, and is a view showing a cross section of the main body 2 in the thickness direction.

When attaching the hanger 6 to the precast board 1, the main body 2 of the precast board 1 is placed between the pair of board members 62. Then, the bolts 7 passed through the holes 614 of each steel plate 61 of the hanging tool 6 are screwed into the inserts 41 of the main body 2.

Further, with a steel plate 66 arranged between one plate material 62 and the main body 2, and a hard rubber 65 arranged between the other plate material 62 and the main body 2, a bolt is screwed into the bolt hole of one plate material 62. 63 is pressed against the steel plate 66. Thereby, the hanging tool 6 can be fixed to the main body 2. The steel plate 66 disperses the pressure acting on the main body 2 from the tip of the bolt 63, and the hard rubber 65 prevents the main body 2 from being damaged and absorbs installation errors of the hanging tool 6 and the like.

The precast board 1 is hoisted up by a crane by passing a wire or the like through the hole 613 of the hanging tool 6, and installed in a concrete joint in the formwork F (see FIG. 1) with the board surface facing vertically.

After the precast board 1 is placed at the joint in this way, reinforcing bars (not shown) of the foundation beam are inserted and placed through the holes 5, and concrete is successively placed on both sides of the precast board 1. In the precast board 1, the concave portions 21 are formed on the front and back surfaces of the main body 2, so that the precast board 1 has good adhesion to the concrete.

As explained above, the precast board 1 of this embodiment is manufactured in advance by forming the recesses 21 on the front and back surfaces of the main body 2 and embedding the reinforcing material 3 therein. By arranging this precast board 1 at the concrete joint, work by professionals such as applying cement adhesive becomes unnecessary, reducing preparation and construction time, leading to reduced labor and improved productivity. Furthermore, the outflow of slag from the splicing section is significantly reduced, and the quality of the splicing section can be stabilized.

Furthermore, the recesses 21 of the main body 2 improve adhesion to concrete placed on both sides of the precast board 1, and the reinforcing material 3 contributes to preventing cracks in the precast board 1 due to vibrations and the like. Furthermore, since the main body 2 is provided with holes 5 through which the reinforcing bars are inserted, the reinforcing bars can be easily arranged.

Furthermore, in this embodiment, by using a net material made of alkali-resistant glass fiber as the reinforcing material 3, cracks in the main body 2 due to vibrations or the like can be suitably suppressed.

Furthermore, in this embodiment, by attaching the hanging tool 6 to the insert 41 buried in the main body 2, it becomes possible to suspend and transport the precast board 1, and by burying the insert 41 so as not to protrude from the main body 2, The insert 41 does not become a hindrance when the precast board 1 is temporarily placed.

However, the present invention is not limited to the above embodiments. For example, the precast board 1 of this embodiment is used for the concrete joints of foundations and foundation beams, but the precast board 1 can also be used for the concrete joints of beams on above-ground areas, such as on high floors. In that case, the precast board 1 may be placed on the bottom formwork of the beam above ground. Alternatively, the precast board 1 and the reinforcing bars may be made into a unit in an above-ground work yard, etc., and then placed at a concrete joint of a beam on a high floor or the like. Moreover, the precast board 1 can also be applied to joints of structures other than beams.

Furthermore, in this embodiment, holes 5 are formed in the main body 2 of the precast board 1 as insertion parts for reinforcing bars, but as shown in the precast board 1a in FIG. 6, grooves 5a can be provided in the end surface of the main body 2 as insertion parts. It is also possible to easily arrange reinforcing bars on the end face of the main body 2. Moreover, instead of inserting the reinforcing bars into the holes 5 of the main body 2, it is also possible to embed mechanical joints 51 for attaching the reinforcing bars in the holes 5 of the main body 2, which also facilitates the reinforcement arrangement.

The groove 5a is provided on the end surface that becomes the upper surface when the precast plate 1a is placed at the joint, and extends in the thickness direction of the main body 2. It is preferable to provide the hanging portions 4 on each of the pair of end surfaces (the left and right end surfaces in FIG. 6), which become side surfaces when the precast board 1a is placed at the joint, avoiding the above-mentioned end surfaces.

The mechanical joint 51 is a cylindrical member, and reinforcing bars on both sides of the precast plate 1a are inserted from both ends of the mechanical joint 51 in the axial direction. In this example, the mechanical joint 51 is of a grout filling type, and each reinforcing bar is fixed to the mechanical joint 51 by filling the inside with grout. One end of the mechanical joint 51 protrudes outward from the main body 2, and the grout injection hole is also exposed to the outside of the main body 2. The other end of the mechanical joint 51 is arranged to match the surface of the main body 2 opposite to the surface shown in FIG. 6, and does not protrude from the main body 2. Note that the mechanical joint 51 may be of a screw type that screws and fixes reinforcing bars.

The manufacturing procedure of the precast board 1a is almost the same as the manufacturing procedure of the precast board 1 described above, except that a mechanical joint 51 is placed on the bottom of the steel formwork 9 instead of the material 91 (see FIG. 3). and fix it. Moreover, the materials for forming the grooves 5a are also fixed inside the steel formwork 9 in advance.

In addition, it is also possible to manufacture a precast board with reinforcing bars placed in the holes 5 by placing reinforcing bars that penetrate the bottom of the steel formwork 9 instead of the material 91, but the steel formwork It takes time and effort to process the reinforcing bar penetration part 9.

Further, in this embodiment, the recesses 21 are formed in the main body 2 by washing away uncured concrete using a hardening retardant, but the method for forming the recesses 21 is not limited to this. For example, it is also possible to form the recesses 21 in the main body 2 by using a mold having a convex part as a formwork when manufacturing the main body 2, or by placing a sheet having a convex part in the mold. . Further, the configurations of the hanging portion 4 and the hanging tool 6 are not limited to those described above, and may be any configuration as long as the precast board 1 can be hung safely. For example, a through hole may be provided in the main body 2 as the hanging portion 4 for passing a wire or the like.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that those skilled in the art can come up with various changes or modifications within the scope of the technical idea disclosed in this application, and these naturally fall within the technical scope of the present invention. Understood.

1, 1a: Precast board 2: Main body 3: Reinforcement material 4: Hanging part 5: Hole 5a: Groove 6: Hanging tool 21: Recessed part 41: Insert 42: Anchor 51: Mechanical joint

Claims (6)

A method for manufacturing a precast board to be placed at a concrete joint, the method comprising:
The precast board is
A flat concrete body with recesses formed on the front and back sides,
a reinforcing material for preventing cracks embedded in the main body and arranged in an in-plane direction of the main body;
a hanging part provided on an end surface of the main body;
Equipped with
An insertion part for inserting the reinforcing bar is provided in the main body ,
When producing the precast board,
With the net-shaped reinforcing material placed on the bottom of the formwork, concrete for the main body is poured into the formwork, the concrete is passed through the mesh of the reinforcing material to the bottom side of the formwork, and A method for producing a precast board, characterized in that the reinforcing material is raised from the bottom of the formwork . A precast board placed at a concrete joint,
A flat concrete body with recesses formed on the front and back sides,
a reinforcing material for preventing cracks embedded in the main body and arranged in an in-plane direction of the main body;
a hanging part provided on an end surface of the main body;
Equipped with
a mechanical joint for attaching reinforcing bars is provided on the body ;
The mechanical joint is a cylindrical member, and the reinforcing bars on both sides of the precast plate are inserted from both ends of the mechanical joint in the axial direction,
A precast board , wherein one end of the mechanical joint protrudes from one surface of the main body, and the other end is arranged to match the other surface of the main body . 2. The method of manufacturing a precast board according to claim 1 , wherein the reinforcing material is a net material made of alkali-resistant glass fiber. 2. The method of manufacturing a precast board according to claim 1, wherein the insertion portion is a hole that penetrates the main body in a thickness direction. 2. The method of manufacturing a precast board according to claim 1, wherein the insertion portion is a groove provided in an end surface of the main body. 2. The precast board according to claim 1 , wherein the hanging part has a bolt hole on the inner surface for use in attaching a hanging tool, and includes an insert embedded in the main body so as not to protrude from an end surface of the main body. Production method .

Images