JP3197235B2 - Construction method of concrete structure using precast embedded formwork - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a concrete structure using a buried formwork made of a cement precast plate.

[0002]

2. Description of the Related Art In contrast to the conventional formwork method using plywood as a veneer, a buried formwork made of a cement precast board is used from the viewpoint of environmental protection aiming at protection of forest resources and reduction of industrial waste. Various methods of constructing concrete structures have been proposed. The use of such a buried form provides, in addition to the advantages of environmental protection described above, a reduction in man-hours required for assembling and dismantling the form and simplification of the construction, thereby achieving labor saving and shortening of the construction period. It is possible to work without the need. Further, there is no need for repair work for bubbles, junkers, etc. generated after the baffle is removed, and there is also an advantage that the finishing of the wall surface is simplified.

In addition, cracks occur due to drying shrinkage of concrete, neutralization of concrete due to air pollution, or rusting and freezing of reinforcing steel caused by salt infiltration due to flying salt in coastal areas or spraying salt calcium in cold areas. Various factors that significantly reduce the durability and aesthetics of cast-in-place concrete, such as deterioration due to melting, can be prevented by coating with a durable cement precast plate.

[0004] As the cement precast plate, there is a case where a thin cement extruded plate manufactured by extruding and kneading cement and aggregate as main raw materials with reinforcing fibers is used. This has the advantage that the material cost per unit area is low because mass production is possible at the factory. or,
Because of the extrusion method, the cross-sectional shape and length are free and thin
It is easy to produce a long object and a complicated cross-sectional shape is possible, so that an appropriate uneven shape can be formed on the back surface. In addition, it has the advantages of relatively high bending strength and high material density, resulting in a smooth surface, good dimensional accuracy, and excellent appearance. For this reason, the thin cement extruded plate has good workability as a mold and good integration with concrete, and is therefore a material expected to expand its use as a buried mold.

[0005]

However, the dense and hard characteristics of the thin cement extrusion molding plate are not suitable for the operation of drilling a separator hole or the like. Further, since the reinforcing fibers are arranged in the extrusion direction, the bending strength in the extrusion direction is high, but the direction perpendicular thereto is weak. For this reason, even when an uneven groove is formed in the cross section, cracks may occur in the weak axis direction when an excessive force acts.

However, in the conventional method of constructing a cement precast plate including a thin cement extrusion molding plate, similar to the conventional construction method, a plastic cone and a shaft foot are used to bind a flutter material such as a single pipe with a tie, and a sealing material. Since the board was fastened,
A so-called separation hole for inserting a shaft foot was required on the brace plate surface. Not only is it difficult to drill such a separator hole in the field, but also in the case of a thin plate, the separator hole is a weak point and cracks are easily generated.

[0007] The present invention solves the above-mentioned problems, and can be mounted on a form supporting material without drilling a separator hole in the surface of a cement precast plate. Moreover, it is an object of the present invention to provide a method for constructing a concrete structure using a precast buried formwork that is easy to assemble.

Further, concrete is brought into close contact with the back surface of the buried formwork to ensure integration, no local stress is generated in the cement precast plate abutting on the form support material, and it is possible to prevent spillage during concrete casting. It is another object of the present invention to provide a method of constructing a concrete structure using a precast buried formwork which is easy to perform post-processing at the time of demolding and is particularly suitable for a railing on a bridge deck.

[0009]

In order to solve the above-mentioned problems, a method of constructing a concrete structure using a precast buried formwork according to the present invention is directed to a method for constructing a concrete board made of a cement precast board, the surface of which is separated from cast concrete. A locking part is provided inside, and the legs that can rotate outward while holding the weight of the baffle plate with the fastening member connected to this locking part
Prepared on the upper and lower face plates extending from the brace plate fastening part
Glue a rubber elastic body that protrudes a projection for preventing slag leakage,
A chamfer is projected from the rubber elastic body of the upper face plate,
Has a similar shape to the cross-sectional shape of the structure that has the separation hole
It is a steel portal frame structure assembled in a grid,
Installed from the top of the wall reinforcement laid, and through the separator hole
The lower part of the formwork is attached to the formwork support material that is tied with the separator, concrete is cast after fixing the formwork support material, and after the concrete is hardened, the formwork support material is removed while the slabs are embedded and the bridge floor slab is removed. A feature is to construct an upper wall railing . Here, the surface or the inside separated from the cast concrete refers to the outer surface, the side surface, and the inside of the board, and the locking portion is not buried in the cast concrete.
That is, this construction method means a configuration in which a slab can be attached to a form support without forming a hole in at least the surface of the cement precast plate.

[0010] As a construction method of providing the locking portion inside the wood board, a drill screw is used as a fastening member, and a screw hole previously drilled in the form supporting material is inserted into a prepared hole formed in the wood board to insert a drill screw. It is desirable to use a method of screwing and attaching the stiffener to the form support material. The diameter of the drill screw is smaller than the diameter of the separator, and is large enough to easily form a prepared hole in the cement precast plate. Also, the cement precast board is
The screw must be dense enough to be screwed into the drilled hole to screw the drill screw, and this screwing must maintain at least the weight of the slab. When removing the form support material, the engagement between the two is released by removing the drill screw.

As a construction method of providing the locking portion on the surface of the board, a method of using an adhesive having an adhesive force capable of holding the board and easily peeling off the mold as a fastening member, and a method of providing a surface of the board. There is a method in which a hook is hooked on the protrusion to fasten the hook.

As the cement precast plate, a thin cement extrusion molding plate is desirable, and as the form supporting material, it is desirable to use a steel frame member assembled in a lattice shape similar to the cross-sectional shape of the structure. The separator is not disposed on the steel frame member in a range where the thin cement extrusion molding plate is to be mounted, and the rigidity of the frame member supports the concrete casting load in the range.

Further, it is desirable that the thin cement extrusion molding plate is provided with concave and convex grooves on the back surface, and the rising portions of the grooves are inclined in the air bleeding direction when concrete is poured. The groove is desirably shaped so that the tip of the convex part widens to ensure the integrity with concrete, but when the concave-convex cross section is vertical, the rising part of the groove is oriented in one direction so that the air in the concave part can rise quickly. Keep tilted.

It is desirable that a rubber elastic body be adhered to the inner surface of the steel frame member to which the flexible plate is fixed. This rubber elastic body prevents the local stress from being generated in the stiffened board by bringing the stiffened board and the frame member into surface contact and uniformly supporting the load at the time of driving.

In the case where the concrete structure is to be a railing on the bridge floor slab, the steel frame member has an outwardly rotatable leg portion and an upper face plate extending from the brace plate fixing portion. A gate-type frame that glues a rubber elastic body that projects projections to prevent spills on the lower face plate, a chamfered portion protrudes from the rubber elastic body of the upper face plate, and a separate hole in the lower face plate It is desirable to have a structure, in this case, it is installed from the upper part of the wall reinforcement laid in advance, and the lower part of the form is fastened by a separator through a separator hole.

The rubber elastic body adhered to the upper and lower face plates is provided with a projection for preventing spillage at a lap portion with the stiffener plate. The rubber elastic body disperses the load, seals the gap between the veneer plate and the elastic plate, and further facilitates the separation between the concrete and the face plate at the time of demolding. The upper part of the steel frame member is fixed, but the lower part is free. Therefore, after setting the form on the floor slab, the legs are opened, the separator is inserted, and the steel frame member is fixed using the fastener.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a cross-sectional view of a formwork apparatus installed by the construction method of the present invention, FIG. 2 is a perspective view of a steel frame member, FIG. 3 is an enlarged cross-sectional view showing a fastening state of the steel frame member and a precast embedded formwork, FIG. 4 is a cross-sectional view of the precast embedded mold, and FIG. 5 is an enlarged cross-sectional view of the upper part of the steel frame member.

The formwork apparatus 1 includes a stiffener plate 2 made of a cement precast plate and a formwork support member 3 for fastening the same.
Fix with pipe support 4 or the like. After the concrete 5 is cast and an appropriate curing period has passed, the stiffener 2 and the form support 3
Is completed, and the construction of the structure is completed by removing the form support material 3.

The flexible board 2 is lightweight and has high bending strength.
It is desirable to use a thin cement extrusion molding plate that can be continuously mass-produced in a factory and can form an arbitrary cross-sectional shape. However, a cement precast plate that can be fastened using a drill screw 6 is not limited to this. Not something. This fastening state will be described with reference to FIG. Screw holes 7 are previously drilled at appropriate intervals in the form support material 3, and a pilot hole 8 is drilled in the cut board 2 in accordance with this. The drill plate 6 is screwed into the pilot hole 8 to attach the cut plate 2 to the form support member 3.

Here, the diameter of the drill screw 6 is, for example, 4.5 m.
It is appropriate that the diameter of the pilot hole 8 when it is set to m is about 4 mm. As described above, the diameter of the prepared hole 8 is such that the separation hole which is normally formed is 10 mm.
Compared to the case, the size is much smaller, so that even a dense cement precast plate can be easily perforated. In addition, since the diameter is small, the influence of perforation is small and cracks are unlikely to occur. When the drill screw 6 is screwed into the pilot hole 8, the screw thread bites into the hole wall, and the weight of the stiffener plate 2 is held by screwing.

On the other hand, the form supporting material 3 for fastening the flexible plate 2 is
A steel frame member assembled in a lattice having a shape similar to the cross-sectional shape of the structure is used. As shown in FIG. 1, in this steel frame member, no separator is arranged in an area where the thin cement extrusion molding plate is mounted. Further, a rubber elastic body 9 is adhered to the inner surface where the flexible plate 2 is fixed. The thickness of the rubber elastic body 9 is 2 to
About 5 mm is appropriate.

The thin cement extrusion forming plate constituting the stiffening plate 2 has a concave-convex groove on the back surface. This groove is widened at the tip of the convex portion 2a for integration with concrete, but the rising portion 2b is inclined in the air bleeding direction when concrete is poured, that is, in the vertical upward direction as shown in FIG. I have. The thin cement extrusion molding plate suitable for the present invention has a thickness of 15 to 30 mm and a width of 300 to 600 mm, and is appropriately selected from the layout dimensions of the structure. Member length is 2,000 ~
5,000 mm, preferably 2,500 to 3,0
00 mm.

The thin cement extrusion molding plates are connected to each other by a male part 2c.
The female part 2d is fitted and connected to the female part 2d, and a sealing process is performed by inserting a standard sealing material 2e (for example, foamed rubber-like bead) into the female portion 2d or by injecting an irregular sealing material (for example, silicon).

In this embodiment, the present invention is applied to a wall railing constructed on a floor slab 10 of a bridge, and a steel frame member serving as a form supporting material 3 has a leg portion which can rotate outward. 3a is provided on one side surface and has an upper face plate 3b extending above the fastening portion of the baffle plate and a lower face plate 3c extending downward, and a cross member 3d is fixed to the top to form a gate-shaped frame structure. .

The rubber elastic body 9 adhered to the entire surface of the upper face plate 3b is provided with a chamfered portion 9a and a projection 9b for preventing slag leakage. The same applies to the rubber elastic body 9 adhered to the entire surface of the lower face plate 3c. The projection 9b is projected and a separation hole is drilled. As a result, it is possible to omit the work of attaching / detaching the face wood or the slick leakage seal material.

The rubber elastic body 9 distributes the load by its elastic deformation, thereby preventing the crack from being generated in the thin cement extrusion molding plate and sealing the gap between the rubber plate 9 and the slab. Further, since the rubber elastic body 9 has less adhesion to concrete than metal, the concrete 5 and the face plate can be easily separated at the time of demolding, and cleaning after demolding becomes easier.

The formwork apparatus 1 is mounted with a cut plate 2 and mounted on a draining section formwork 13 from above the wall arrangement 11 using a crane or the like with a sealing material inserted, and temporarily fixed. Next, the leg portion 3a is opened, the separator 12 is inserted, and the leg portion 3a is fixed using a required fastener. Thereafter, a side frame (not shown) is attached and the whole is fixed at a predetermined position with a pipe support 4 or the like, and concrete 5 is poured.

After the required curing period has elapsed, the fastening between the stiffener plate 2 and the form support material 3 can be released by removing the drill screw 6, and when the form support material 3 is removed, the surface is formed by the cement precast plate. The covered concrete railing is completed. Since most of the wall railing is covered with a cement precast plate, the finishing work on the concrete surface is small, and the form supporting material 3 can be repeatedly used after simple cleaning.

By using such a construction method, complicated assembling and disassembling operations of the formwork are simplified, the construction period is shortened, and it is not affected by the presence or absence of skilled workers. In addition, it is possible to reduce the labor required for finishing the concrete wall surface and to realize a high-quality wall railing capable of maintaining durability and aesthetic appearance for a long time.

In the above embodiment, a description has been given of a wall railing constructed on a floor slab of a bridge. However, a cement precast plate is used as a buried formwork, and the surface or the inside of a seki plate separated from cast concrete is used. If a structure is adopted in which a stop portion is provided and attached to the form supporting material while holding the weight of the veneer plate with a fastening member connected to the lock portion, and no separator is disposed at least in the cement precast plate portion, the wall may be used. It can be applied to any method of constructing a structure such as a column, a beam, and the like.

As a construction method of providing the locking portion on the surface of the veneer plate, there is also a method of hooking a projection on the surface of the veneer plate with a hook and fastening as shown in FIG. The protrusion uses a male portion 2c, which is a fitting portion of the stiffening plate 2, and the front end of the latch 16 is hooked to the outer surface of the form support member 3 with a nut.

[0032]

As described above, the method for constructing a concrete structure using the precast buried formwork according to the present invention is a method for constructing a concrete board made of a cement precast board, which is separated from the cast concrete by the surface or inside thereof. Is established,
Since the plate is attached to the form supporting material while maintaining the weight of the slab without making a hole in the plate, cracks can be prevented even from a thin cement precast plate.

The form supporting material has a similar shape to the cross-sectional shape of the structure.
Using a steel portal frame assembled in a grid-like shape
As a result, complicated assembling and dismantling work of the formwork is simplified,
And is no longer affected by the presence of skilled workers. Outside
Separate hole is drilled in the lower face plate with rotatable legs
Therefore, it is suitable for constructing a wall railing on a bridge deck. or
Protruding protrusions and chamfers on rubber elastic body
Easy post-processing during concrete casting and demolding
To become.

[0034] The construction method according to claim 2 is characterized in that
Form a pilot hole in the recast plate, and insert a drill screw into this pilot hole.
Easy to assemble because it is screwed and attached to the form support material
The drill is used to release the fastening between the slab and the formwork support material.
Disassembly work is easy because it is possible by removing screws
To become.

In the construction method according to the third aspect , the stiff board is
Since a thin cement extrusion molding plate is used, it is an inexpensive material.
Even so, the durability of the buried formwork increases and the appearance is also excellent. or
Formwork support material should have at least
Glue the elastic body, mold the cement precast plate
The frame support material evenly supports and generates local stress on
That to prevent cracking due to.

[0036]

[0037]

[0038]

[Brief description of the drawings]

FIG. 1 is a sectional view of a formwork device.

FIG. 2 is a perspective view of a steel frame member.

FIG. 3 is an enlarged sectional view showing a fastening state between a steel frame member and a precast embedded mold.

FIG. 4 is a sectional view of a precast embedded mold.

FIG. 5 is an enlarged sectional view of an upper part of a steel frame member.

FIG. 6 is an enlarged sectional view showing another fastening state of the steel frame member and the precast embedded mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Formwork apparatus 2 Stiff board 3 Formwork support material 5 Concrete 6 Drill screw 7 Screw hole 8 Pilot hole 9 Rubber elastic body

Claims (3)

(57) [Claims] An anchoring portion is provided on the surface or inside of a slab made of a cement precast plate, which is separated from the cast concrete, and a fastening member connected to the anchoring portion keeps the stiffening plate's own weight while moving outward. Equipped with rotatable legs,
Prevents spills on the upper and lower face plates extending from the plate fastening part
Glue a rubber elastic body with a projection for stopping
The rubber elastic body has a chamfered part, and the lower face plate has a separate hole.
In a grid shape similar to the cross-sectional shape of the structure in which the holes are drilled
Steel frame structure, pre-layed
Installed from the top of the reinforced wall arrangement and the separator through the separator hole
In mounting the mold bottom into a mold pre-supports that Tightened to Da設concrete after fixing the mold pre-supports, by removing the left mold pre-supports were buried cough plate after concrete curing
A method of constructing a concrete structure using a precast buried formwork, comprising constructing a wall railing on a bridge deck . 2. A drill screw is used for the fastening member, and the locking portion is a pilot hole formed in a cut board by inserting a screw hole previously drilled in a form supporting material. 2. The method for constructing a concrete structure using a precast buried formwork according to claim 1, wherein the stiffener is attached to the form support by screwing a drill screw. 3. The rigid board is a thin cement extruded plate , and at least the rigid board is fixed to a form supporting material.
Claim, characterized that you adhere the rubber elastic body on the inner surface 1
A method for constructing a concrete structure using the precast embedded formwork according to the above.