JP6010835B2 - Manufacturing method of mortar plug for con or insert - Google Patents

Description

The present invention relates to a method of manufacturing a mortar plug for con or insert.

  For example, in a bridge construction site, scaffolding inserts are embedded so as to face the surface of concrete forming the bridge. A mounting bolt for installing the scaffold is screwed onto the scaffold insert, and the scaffold is assembled using the mounting bolt. Upon completion of the construction, the scaffold is dismantled and the bolts screwed to the scaffold insert are also removed. Then, the surface of the embedded scaffold insert is exposed on the surface of the concrete bridge, and the scaffold insert hole remains.

Conventionally, the hole of the insert for scaffolding was sealed with a cap made of synthetic resin and then the surface was mortared, the mortar was put into the whole hole, or the hole was closed with a stopper.
An example of the stopper is disclosed in Patent Literature 1 and Patent Literature 2.

Japanese Patent No. 2941170 Japanese Patent No. 30623388

It is preferable to use a stopper of the prior art to close the hole of the insert for scaffolding or to close the hole of the corner in terms of excellent workability and good finishing.
However, in recent years, when the scaffold insert is embedded in the lower surface of the bridge, etc., when the hole of the scaffold insert embedded in the lower surface is closed with a conventional stopper, the effects of secular change, long-term vibration, etc. Therefore, it has been pointed out that there is a possibility that the stopper may come off rarely.

The present invention was made based on such a background, and is a mortar plug for closing a hole such as a container or insert. The main object of the present invention is to provide a method for producing a mortar plug for a container or insert that can maintain a state in which a hole is closed.

The invention according to claim 1 is a method for producing a mortar plug for a container or insert, wherein a mortar plug casting mold is formed vertically in the longitudinal direction, and the upper part is the tip of the mortar plug. The bottom is the mold of the main body of the mortar plug, the bottom is the rectangular resin mold with a plurality of casting molds, and the bottom of each casting mold Auxiliary mold, a plurality of auxiliary molds standing so that a convex plate for forming a screwdriver hole is located at the center of the bottom surface in each casting mold, and preparing each casting mold, Pour liquid mortar material mixed with cement, silica fume, fluidized material, silica sand and water from the upper side which is the mold of the screw shaft part, and vibrate the entire resin mold. Air is deaerated inside each casting mold Fill the mortar material without any gaps, and after the mortar material solidifies, remove the auxiliary mold from the resin mold, remove the mortar plugs individually molded from each casting mold while rotating, cure the removed mortar plugs, and then mortar Hold the mortar plugs in alignment so that the screw shafts at the tip of the plugs are aligned downward, and immerse the screw shafts at the tip of the mortar plug and the tip of the main body in water-swellable paint. It is a method for producing a mortar plug for kon or insert, characterized in that it includes each treatment of pulling up and drying the water-swellable paint .

According to the manufacturing method of the mortar plugs of this invention, by using a mold, by hand each mortar plug, he can be to build up the desired type, no variation in quality, to provide a high quality of the mortar plugs it can.

  In addition, since the mortar material contains silica fume, fluidized material, and silica sand, the mortar plug has a high hardness, is non-hydrophilic, is optimal as a plug for plugging holes, and can form a screw shaft well. Can be manufactured.

FIG. 1 is a schematic diagram of an example of a construction site where a scaffold is constructed using a scaffold insert on a PC (prestressed concrete) bridge. FIG. 2 is a view for explaining a scaffold insert (CT insert) and a mortar plug according to one embodiment of the present invention, and the CT insert is shown in a cross section. 3 is a front view (FIG. 3 (A)), a rear view (FIG. 3 (B)), a right side view (FIG. 3 (C)), and a longitudinal sectional view of the mortar plug according to one embodiment of the present invention. (FIG. 3D). FIG. 4 is a diagram showing a modification of the mortar column. FIG. 5A is a schematic diagram showing a manufacturing process of a mortar plug, and shows how a mortar material is filled in a mold. FIG. 5B is a schematic diagram showing a manufacturing process of the mortar plug, and shows a state in which the solidified mortar plug is taken out from the mold. FIG. 5C is a schematic diagram illustrating a manufacturing process of a mortar plug, and is a diagram for explaining how to apply a water-swellable coating material to the surface of the completed mortar plug.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram of an example of a construction site in which a scaffold is constructed using a scaffold insert (hereinafter referred to as “CT insert”) on a PC (prestressed concrete) bridge.
In FIG. 1, a PC bridge 1 has a substantially T-shape, and two PC bridges 1 are arranged on the left side and the right side in the figure.

A plurality of CT inserts 2 are embedded in each PC bridge 1. The CT insert 2 is embedded at a predetermined position in the PC bridge 1 and is used for installation of the scaffold 3 and the like and for holding the formwork 4 during construction.
FIG. 2 is a cross-sectional view for explaining a specific configuration of the CT insert 2 and a view showing a mortar plug 20 according to one embodiment of the present invention applied to the CT insert 2.

  Referring to FIG. 2, the CT insert 2 includes an insert body 5 formed of mortar and a nut portion 6 fixed to the insert body 5. The insert body 5 has a cylindrical shape with a slight taper so that the diameter of the insert body 5 increases slightly from the front end surface 7 toward the rear end surface 8. A through hole 9 is formed from the front end surface 7 toward the rear end surface 8 on the opposite side. The through-hole 9 is a hole with a taper that is slightly narrowed from the front end surface 7 toward the rear end surface 8.

A nut portion 6 that is inserted into the insert body 5 from the rear end face 8 and fixed to the insert body 5 is provided on the rear end face 8 side of the through hole 9. The axial center of the through hole 9 and the axial center of the nut portion 6 are matched to extend on the same line.
The nut portion 6 includes a shaft 12 having a cylindrical nut 11 and a flange 13 provided on the rear end side of the shaft 12 so as to protrude outward from the shaft 12. The scissors 13 serve to prevent the CT insert 2 from coming off from the embedded concrete.

Further, if necessary, a step portion 14 may be formed at a predetermined position on the peripheral surface of the insert main body 5 such that the outer periphery on the rear end surface 8 side becomes thicker than the front end surface 7 side.
The CT insert 2 is embedded in the concrete during construction, the tip end surface 7 is flush with the concrete surface, and the through hole 9 is recessed from the concrete surface. During construction, a bolt is inserted into the through hole 9, and a screw formed at the tip of the bolt is screwed into the nut 11 and fixed. A scaffold or the like is attached to the bolt protruding from the tip surface 7.

When the construction is finished, the bolts screwed into the nut 11 are removed, so that the CT insert 2 embedded in the concrete has its end face 7 exposed on the concrete surface and a through hole 9 provided. It will be in a (depressed) state.
In order to block the through hole 9 and prevent water or the like from entering the inside of the CT insert 2, particularly the metal nut portion 6, through the through hole 9, it is necessary to close the through hole 9. The plug for that is the mortar plug 20 according to this embodiment.

The mortar plug 20 is formed of mortar as a whole, and has a cylindrical main body 21 with a taper that is slightly tapered in the direction of entering the through hole 9 of the CT insert 2. The taper shape of the main body 21 is the same as the taper shape of the through hole 9 and can be inserted almost exactly into the through hole 9.
The mortar plug 20 includes a screw shaft portion 23 made of mortar that protrudes from the tip 22 of the main body 21. The screw shaft portion 23 is formed so as to be able to be screwed with the nut 11 of the CT insert 2 (for example, the screw standard is M12).

The axial length L1 of the main body 21 (the length in the horizontal direction in FIG. 2) is the axial length L2 of the through hole 9 of the CT insert 2 (the horizontal length in FIG. 2 and the depth of the through hole 9). Can also be said.)
The mortar plug 20 further has a water-swellable paint 24 applied to at least the peripheral surface of the main body 21 near the tip 22 side and the peripheral surface and the tip surface of the screw shaft portion 23. That is, the water-swellable paint 24 is applied to the surfaces of the screw shaft portion 23 and the main body 21.

As the water-swellable paint 24, various known water-swellable paints can be used as long as they are water-swellable, that is, they can absorb water and form water-containing materials when contacted with water.
As an example, a paint base containing a water-swellable polymer substance is blended, and a paint base in which a synthetic resin or rubber is dissolved in a solvent is suitable. As the synthetic resin, a vinyl resin or an acrylic resin is used. And polyurethane resins, epoxy resins, phenol resins and the like. Examples of water-swellable polymer materials include mixtures of lower olefin-maleic anhydride copolymers, urea resins and melamine resins, and starches such as carboxymethyl. In addition to modified starches such as modified starch and cyanoethylated starch, modified polyvinyl alcohol and the like can be exemplified, and examples of rubber include natural rubber, synthetic rubber and recycled rubber.

After the through hole 9 of the CT insert 2 is closed by the mortar plug 20, when water enters the gap between the mortar plug 20 and the through hole 9, the water-swellable paint 24 swells and the mortar plug 20 The gap with the through hole 9 is sealed to prevent water from entering the inside of the CT insert 2 (nut portion 6).
FIG. 3 is a front view (A), a rear view (B), a side view (C), and a side longitudinal sectional view (D) for explaining a more specific configuration of the mortar plug 20.

Referring to FIG. 3, the mortar plug 20 is integrally formed of mortar as a whole, and a screw shaft formed of mortar integrally with the main body so as to protrude from the tip 22 of the columnar main body 21. A portion 23 is provided.
Further, in the rear end face 25 of the main body 21, a recess for rotating the mortar plug 10 in order to insert the mortar plug 20 into the through hole 9 and screw the screw shaft portion 23 with the nut 11 of the CT insert 2. 26 is formed. The recess 26 is referred to as a so-called screwdriver hole.

In this embodiment, the outer peripheral surface shape of the main body 21 of the mortar plug 20 is a cylinder provided with a taper slightly tapered toward the tip 22 side in accordance with the inner diameter of the through hole 9 of the CT insert 2. The shape is not limited to this.
That is, according to the shape of the through hole 9, as shown in FIG. 4, the outer diameter of the rear end portion 21B is thick, the stepped portion 21S is added and the tapered cylindrical portion 21F is continued, and the screw shaft portion 23 is provided at the tip portion. It is good also as a mortar plug of the projected external shape.

Next, with reference to FIG. 5A, FIG. 5B, and FIG. 5C, the manufacturing method of the mortar stopper 20 is demonstrated easily.
In manufacturing the mortar plug 20, a resin mold 30 having a rectangular shape in plan view as shown in FIG. 5A is used. The reason why the mold 30 is made of resin is that it is difficult to take out the solidified mortar plug 20 from the mold 30 unless the mold 30 has some elasticity.

The mold 30 is formed with a casting mold 31 for each of the mortar plugs 20 formed in the longitudinal direction. In each casting mold 31, the upper part of FIG. 5A is the mold of the screw shaft part 23 at the tip of the mortar plug 20, and the lower part is the mold of the main body 21 of the mortar plug 20.
The bottom surface of each casting mold 31 is closed with an auxiliary mold 32 made of a separate member, and a convex plate 33 for forming a screwing hole standing on the auxiliary mold 32 is provided in the casting mold 31. Located in the center of the bottom.

A liquid mortar material is poured into each casting mold 31 formed in the mold 30.
Examples of the liquid mortar material include a mixture of cement, silica fume, fluidizing material, silica sand and water. Use of a fluidized material has the advantage that the fluidity of each material is improved and the amount of water added can be reduced. By reducing the amount of water to be added, the non-hydrophilic property of the mortar plug 20 to be manufactured is less likely to pass water. Further, the strength of the screw formed on the screw shaft portion 23 is improved.

The cement to be mixed may be ordinary cement powder, but may be mixed with white cement as necessary. This is because the color of the finished mortar plug becomes white and the appearance is improved.
After the liquid mortar material has flowed into each casting mold 31 of the mold 30, the entire mold 30 is vibrated to degas the air contained in the mortar material in each casting mold 31, and into each casting mold 31. Ensure that the mortar material is filled without any gaps.

Then, after the mortar material is solidified, the mold 30 is inverted and the auxiliary mold 32 is removed, so that the mortar plug 20 solidified in each casting mold 31 is obtained as shown in FIG. 5B.
The operation of removing the mortar plug 20 from the mold 30 is performed while rotating the molded mortar plug 20 one by one. At that time, the tip of the driver is inserted into the concave portion 26 which is a screwdriver hole, and the mortar plug 20 is removed from the casting mold 31 while rotating.

  Then, after curing the completed mortar plug, as shown in FIG. 5C, the plurality of mortar plugs 20 are aligned and held on the mounting plate 34 so that the screw shaft portions 23 at the tip of the mortar plug 20 are arranged downward. . Then, the screw shaft portion 23 at the tip of the mortar plug 20 and the tip side portion of the main body 21 are dipped in the water-swellable paint pool 35 and pulled up from the paint pool 35 to dry the water-swellable paint.

Thereafter, each mortar plug 20 is inspected, the overall dimensions of the mortar plug 20 and the coating thickness of the coating 24 are inspected, and a product that passes the inspection becomes a product.
The present invention is not limited to the embodiment described above. In the above-described embodiment, the mortar plug 20 applicable to the CT insert 2 has been described. However, a container (also referred to as “CT container”), that is, a mold retainer used for retaining a mold when placing cement is used. The present invention can also be applied to mortar plugs that are applied to other corns and plug holes in the corn.

  In addition, various design changes can be made within the scope of the matters described in the claims.

1 PC Bridge 2 CT Insert 20 Mortar Plug 21 Body 22 Tip 23 Screw Shaft 24 Paint 25 Rear End Face 26 Concave

Claims (1)

A method of manufacturing a mortar plug for a container or insert,
A mortar plug casting mold is formed longitudinally in the vertical direction. In the casting mold, the upper part is the mold of the screw shaft at the tip of the mortar plug, and the lower part is the mold of the mortar plug body. A rectangular resin mold in which a plurality of casting molds are arranged, and an auxiliary mold for closing the bottom surface of each casting mold, each of which has a convex plate for forming a screw hole. Prepare a plurality of auxiliary molds standing in the center of the bottom inside,
A liquid mortar material in which cement, silica fume, fluidizing material, silica sand and water are mixed is poured into each casting mold from the upper side which is the mold of the screw shaft portion.
The entire resin mold is vibrated, the air in each casting mold is degassed, and each casting mold is filled with mortar material without gaps,
After the mortar material has solidified, remove the auxiliary mold from the resin mold, remove the mortar plugs individually molded from each casting mold,
After curing the removed mortar plugs, hold the mortar plugs in alignment so that the screw shafts at the tip of the mortar plugs are aligned downward.
For kon or insert, characterized in that it includes each treatment of immersing the screw shaft portion at the tip of the mortar plug and the tip of the main body in a water-swellable paint and then drying the water-swellable paint. A method for producing a mortar plug.

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