JP3048465B2 - Formwork and concrete panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a formwork-concrete panel. More specifically, the present invention relates to a formwork / concrete panel that has a high degree of freedom in the arrangement of reinforcing bars, facilitates installation of piping and the like, enables nailing, and can improve workability.

[0002]

2. Description of the Related Art Conventionally, a method of constructing a concrete structure by assembling a formwork and pouring concrete into the formwork has been adopted. However, it takes time and effort to assemble and disassemble the formwork. For this reason, in recent years, a method has been adopted in which a concrete panel previously manufactured in a factory is used as a formwork and is used as a part of a structural material after concrete is cast. In this case, in order to reduce the weight of the building, reduce the construction cost and increase the space utilization rate, a synthetic resin foam, a wooden box, a lightweight embedding material such as cardboard is provided on the concrete panel, It has been practiced to create a substantial "cavity" in the slab. This "cavity" is typically about 20% of the total. FIG. 6 is a sectional explanatory view of such a conventional concrete slab, and FIG.
Is a concrete panel manufactured at a factory, and lightweight embedding members 11 such as synthetic resin foams are provided on the concrete panel 10 at appropriate intervals. Numeral 12 denotes cast-in-place concrete, which constitutes a slab integrally with the concrete panel 10. 13 is a reinforcing bar arranged in the slab.

[0003]

However, the above-mentioned conventional concrete panel is troublesome since a lightweight embedding material such as a synthetic resin foam must be fixed. Also,
It is necessary to cut lightweight embedding material when constructing buried piping. There is a problem that the unevenness of the surface is severe and the strength of the lightweight embedding material is low, so that it is difficult to walk, and if the lightweight embedding material is melted at the time of welding of the reinforcing steel, it may be ignited.

[0004] Furthermore, it is difficult or impossible to nail both the lightweight embedding material and concrete, and it is necessary to use a holing anchor or the like in a portion requiring fixing.
The work is troublesome.

[0005] In view of the circumstances described above, an object of the present invention is to provide a formwork-concrete panel that is easy to pipe and arrange, has excellent workability, and can be nailed.

[0006]

According to the present invention, there is provided a concrete panel which also serves as a formwork, comprising a normal concrete layer comprising cement, water and aggregate, and an air-dry density of 0.9 to 1.7 g / cm.
cm ³ of the concrete panel from lightweight concrete layer ing
A reinforcing bar is buried in the ordinary concrete layer, and the lightweight concrete layer comprises cement, water,
And synthetic resin foam beads having an average particle size of 0.1 to 1.5 mm
Water-cement ratio is 45% or less
The mixing ratio of the synthetic resin expanded beads is 10 to 55% by volume.
And the lightweight concrete layer is
It is characterized in that those further containing concrete aggregates are hardened . In addition, the mold and
The cleat panel is manufactured in the specified position in the panel formwork.
Arranging rebar in the formwork, cement, water and
Casting ordinary concrete consisting of steel and aggregate;
Before concrete hardens, cement, water and
Casting lightweight concrete made of synthetic resin foam beads
And a method of manufacturing a concrete panel that also serves as a formwork.
Thus, the average particle size of the synthetic resin expanded beads is 0.1 to
1.5 mm, the water cement ratio is 45% or less,
And the mixing ratio of the synthetic resin foam beads is 10 to 55 volumes.
% And the lightweight concrete
It is characterized by adding more concrete aggregate
I have.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a concrete panel which also serves as a formwork according to the present invention.

FIG. 1 is an explanatory sectional view of one embodiment of a concrete panel which also serves as a formwork of the present invention (hereinafter simply referred to as a panel).

In FIG. 1, reference numeral 1 denotes a normal concrete layer;
Denotes a lightweight concrete layer, and 3 denotes a reinforcing bar.

[0010] The ordinary concrete layer in the present invention is a layer made of a conventionally used concrete, and specifically, fine aggregate such as sand and coarse aggregate such as gravel and crushed stone in water and cement. Further, an admixture such as a water reducing agent is blended if necessary. The specific gravity of the ordinary concrete layer varies depending on the composition, but is usually about 2.3.

Next, the lightweight concrete layer will be described. Lightweight concrete is usually cast before the concrete hardens.

The air-dry density of the lightweight concrete in the panel of the present invention is 0.9 to 1.7 g / cm ³ . The composition for obtaining such lightweight concrete includes (1) cement, water and synthetic resin foam beads, (2) cement, water and synthetic resin foam crushed product, (3) cement water and perlite, (4) cement, Water and structural lightweight concrete aggregates are possible.

First, when the pulverized synthetic resin foam of (2) is used, the blending ratio of the pulverized product is about 20 to 55% by volume, and the dimension is preferably about 5 mm or less. . The expansion ratio is preferably 30 to 50 times. However, when a pulverized product is used, there is a problem that the strength is slightly lower than when a foamed bead described later is used.

Next, when the pearlite (3) is used, the blending ratio of the pearlite is about 20 to 55% by volume, and the dimension is preferably about 5 mm or less. The expansion ratio is about 2 to 10 times. However, when pearlite is used, there is a problem that pearlite absorbs much water, and pearlite is easily damaged at the time of mixing, and the quality is not stable.

Further, when the structural lightweight concrete aggregate (4) is used, the mixing ratio of the aggregate is about 40 to 70% by volume, and the dimension is preferably about 15 mm or less. However, when lightweight structural concrete aggregate is used, there is a problem that the specific gravity of the aggregate is high and it is difficult to reduce the weight.

In the compounding of the above (2) and (3), sand, gravel, structural concrete aggregate and the like may be further mixed. Also, a combination of (2) and (3) may be used.

Although the above-mentioned compositions (2) to (4) have the above-mentioned problems, the above-mentioned composition using cement, water and synthetic resin foam beads (1) does not have such a problem. It is the most preferable as a composition for a lightweight concrete layer. That is, the lightweight concrete layer in the present invention, cement, water, and the average particle size 0.1
It is preferable that the resin beads are made of synthetic resin foam beads of up to 1.5 mm, the water cement ratio is 45% or less and the mixing ratio of the synthetic resin foam beads is 10 to 55% by volume.

Hereinafter, this preferred example of formulation will be described in detail.

As cement in the lightweight concrete layer, other than portland cement such as ordinary portland cement and early-strength portland cement, blast furnace cement,
Silica cement, fly ash cement and the like can be used, and it is preferable to use them properly depending on the application.

The expanded synthetic resin beads of the present invention can be obtained by expanding polystyrene, polypropylene, polyethylene, acrylonitrile-styrene copolymer, styrene-ethylene copolymer, polyvinylidene chloride, etc. Although not particularly limited, it is preferably at least 5 times, particularly preferably about 30 to 50 times. If the expansion ratio is less than 5 times, the amount of the synthetic resin is increased, the incombustibility is inferior, and the weight of the concrete is disadvantageously increased. In the present specification, “bead” means a spherical, oval, or cylindrical sphere. In addition,
Of these, spherical spheres are most preferred.

The synthetic resin foam beads are lightweight, have low water absorption, and have an average particle size of 0.1 to 1.5 mm, preferably 0.1 to 1.5 mm.
It is very small, 5 to 1.0 mm, so that when it is mixed with cement and water, the rolling effect makes the concrete flow better. As a result, the water-cement ratio can be reduced while maintaining good workability. The concrete thus obtained is a highly durable lightweight concrete having a small continuous void, a dense and small shrinkage, a low water absorption and a low water permeability, and excellent in freeze-thaw resistance and neutralization performance. If the average particle size of the beads is less than 0.1 mm, the fluidity becomes poor, which is not preferable. On the other hand, if it exceeds 1.5 mm, there is a problem that it is lifted by buoyancy due to its light weight and is separated from the cement paste. This separation can be prevented to some extent by using an admixture such as a thickener, but it is not perfect, and the use of the admixture causes a problem that workability deteriorates. In addition, when the aggregate is large, a defective portion is easily generated, and stress concentration is applied to that portion, so that the strength of the concrete is reduced by about 20 to 30%.

When a crushed product is used in place of the beads as the aggregate, stress is locally applied due to the irregular shape of the aggregate, and the strength is reduced. There is a problem that quality concrete cannot be obtained.

In the present invention, the water cement ratio of the lightweight concrete is 45% or less, preferably 25 to 40%, more preferably 30 to 35%. The reason why the water-cement ratio is small is due to the above-described rolling effect of the fine synthetic resin foam beads, whereby a dense concrete can be obtained. If the water-cement ratio exceeds 45%, the shrinkage increases, the water absorption and water permeability increase, the freeze-thaw resistance and the neutralization performance deteriorate, and the durability of the concrete decreases.

The mixing ratio of the synthetic resin expanded beads is 10 to 55.
% By volume, preferably 20 to 40% by volume. Mixing ratio is 10
When the volume is less than the volume%, the specific gravity of the concrete cannot be reduced, and the heat insulating property is lowered, and there is a problem that the nail cannot be hit. On the other hand, when the volume exceeds 55 volume%, the strength is reduced, There is a problem that flame retardancy (nonflammability) decreases and pull-out resistance of the nail decreases. The capacity% is
It is based on the absolute volume of the synthetic resin expanded beads, and does not consider the voids between particles.

Although the lightweight concrete of the present invention has an air-dry density of 0.9 to 1.7 g / cm ³ , which is lighter than the conventional lightweight concrete, it can obtain the same strength as ordinary concrete. Specifically, the compression strength is 90 ~
300 kg / cm ² (for example, about 180 kg / cm ² at a specific gravity of 1.25)
And a flexural strength of 30 to 70 kg / cm ² (for example, about 50 kg / cm ² at a specific gravity of 1.25). Therefore, it can be used alone as a structural material such as a pillar or a floor.

The lightweight concrete layer of the present invention uses synthetic resin foam beads having a small particle size and a small strength as an aggregate. Since the local strength is reduced, an iron round nail used for wood can be used. Nail pull-out resistant. That is, it is possible to directly nail a lightweight concrete without embedding a piece of wood or the like. This makes it possible to easily attach interior materials and equipment.

The lightweight concrete of the present invention may be a finely pulverized product of sand, gravel, fiber, structural lightweight concrete aggregate, vinyl chloride or chlorinated vinyl chloride resin foam, if desired, in addition to cement, water and synthetic resin foam beads. Etc. can be blended.

As the vinyl chloride resin foam, for example, a foamable composition comprising a vinyl chloride resin, an inorganic substance which may contain inorganic fibers having a diameter of 1 μm or more, an organic solvent and a decomposable foaming agent is foamed. Rigid foam having an expansion ratio of 50 times or more (WO 89
/ 09796) can be used. The vinyl chloride resin in the present invention includes a vinyl chloride homopolymer or a copolymer of vinyl acetate with a copolymerizable monomer, and further includes a blend resin of such a vinyl chloride resin and an inferior amount of another resin. It is. In the hard foam, asbestos is used as the inorganic fiber for health reasons. However, asbestos may be added to asbestos, or asbestos may be used alone. In addition, any material having flexibility other than the rigid foam can be used,
It is particularly preferable that the material is semi-flammable or non-flammable, and the lightweight concrete of the present invention contains inorganic fibers (especially rock wool) as disclosed in JP-A-63-264645 filed by the present inventors. Chlorinated vinyl chloride resin foams filled with certain inorganic substances (such as talc, calcium carbonate, aluminum hydroxide, and magnesium hydroxide) can also be used.

These vinyl chloride or chlorinated vinyl chloride resin foams are used after being crushed to a predetermined size by a crusher. The grinding size is not particularly limited in the present invention, but is preferably 5 mm or less, particularly preferably 2 mm or less. Further, the compounding amount is preferably 0.5 to 5% by weight, particularly preferably 2 to 3% by weight of the cement weight.

The finely pulverized product is mixed in the cement paste and plays a role as a heat insulating material and a binder, whereby the impact property, the surface smoothness, the crack preventing property and the workability of the iron are improved.

The fibers include vinylon, acrylic,
Modacrylic, nylon, polyester, polyethylene, aramid, rock wool, alkali-resistant glass fiber and carbon fiber, etc. can be mentioned, but from the viewpoint of alkali resistance and tensile strength, carbon fiber, aramid fiber, vinylon fiber,
It is preferable to use modacrylic fiber and rock wool fiber. The fiber length is 1 to 30 mm, preferably 2 to 6 mm. If it exceeds 30 mm, the dispersibility becomes poor and the fluidity of the concrete decreases. On the other hand, if it is less than 1 mm, a sufficient reinforcing effect cannot be obtained. The thickness of the fiber is not particularly limited in the present invention, but generally 1 to 20
0 Denier is a guide.

[0032] The amount of the fiber is 0.1% based on the weight of the cement.
It is preferably from 1 to 3% by weight, especially from 0.5 to 1% by weight. If the amount is less than 0.1% by weight, the effect of preventing cracks and the effect of improving impact resistance are small, while if it exceeds 3% by weight, the mixing property becomes poor.

Although the lightweight concrete of the present invention has an air-dry density of 0.9 to 1.7 g / cm ³ , which is lighter than the conventional lightweight concrete, it can obtain the same strength as ordinary concrete. Specifically, the compression strength is 90 ~
300 kg / cm ² (for example, about 180 kg / cm ² at a specific gravity of 1.25)
And a flexural strength of 30 to 70 kg / cm ² (for example, about 50 kg / cm ² at a specific gravity of 1.25). Therefore, it can be used as a structural material such as a pillar or a floor.

Examples of the structural lightweight concrete aggregate include those specified in JIS A 5002. Specifically, artificial lightweight aggregates, natural lightweight aggregates, and by-product lightweight aggregates can be used. Aggregates can be given.
The mixing amount of the structural lightweight concrete aggregate is not particularly limited in the present invention, but is preferably 30 to 50% by weight, particularly preferably 35 to 40% by weight of the whole concrete.

In the conventional lightweight concrete using the structural lightweight concrete aggregate, the specific gravity of the mortar composed of cement and fine aggregate is as large as about 2.3, whereas the specific gravity of coarse aggregate is as small as about 1.0 to 1.5. Therefore, there is a problem that the coarse aggregate is lifted by the buoyancy and the material is separated. For this reason, the conventional lightweight concrete using the structural lightweight concrete aggregate has a drawback that the strength is varied due to the difference between up and down, but in the present invention, cement and synthetic resin foam corresponding to the conventional mortar are used. Since the specific gravity of the mixture with the beads is 1.0 to 1.5, which is almost the same as that of the structural lightweight concrete aggregate, the coarse aggregate does not float up and good mixing properties can be obtained.

The thicknesses of the ordinary concrete layer and the lightweight concrete layer are not particularly limited in the present invention, but are usually 70 to 150 mm and 100 to 200 mm, respectively. The thickness of the cast-in-place concrete layer is usually 70 to 15
0 mm.

The panel of the present invention can have a multilayer structure of a normal concrete layer and a lightweight concrete layer, but can also be composed of only a lightweight concrete layer.
In this case, the thickness of the lightweight concrete layer is usually 150
~ 350mm, and the thickness of the ordinary concrete layer cast on the site is 70 ~ 150mm.

In order to further reduce the weight, a conventional lightweight embedding material can be appropriately used in the concrete panel of the present invention.

The weight of the panel of the present invention and that of the conventional panel were compared with each other. In all cases, the total thickness including the cast-in-place concrete was 350 mm, and the lightweight embedded material part of the conventional panel (a and b in FIG. 5)
The calculation was performed assuming that the size of the lightweight embedding part occupies 50% of the embedding material placement space). Table 1 shows the calculation results, and FIGS.

[0040]

[Table 1]

[0041]

The panel of the present invention does not use a conventional lightweight embedding material, and has an average particle size of 0.1 to 1.5 mm for weight reduction.
The lightweight concrete containing the specific ratio of the synthetic resin foam beads described above is used, and the following effects can be obtained.

(1) Since the upper surface is flat, it is easy to walk and the workability is improved.

(2) Since nailing is possible and it is not necessary to cut the lightweight embedding material, it is possible to easily attach pipes and the like.

(3) There is no fear of fire or the like.

(4) Reinforcement can be freely designed without worrying about the position of the form of the lightweight embedding material.

(5) The heat insulation between the upper and lower floors is improved, and when used as a roof slab, it has a heat shielding effect.

Table 2 below summarizes the above effects in comparison with a conventional panel.

[0048]

[Table 2]

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of one embodiment of a panel of the present invention.

FIG. 2 is an explanatory cross-sectional view of a slab using one embodiment of the panel of the present invention.

FIG. 3 is an explanatory cross-sectional view of a slab using another embodiment of the panel of the present invention.

FIG. 4 is an explanatory sectional view of a slab using still another embodiment of the panel of the present invention.

FIG. 5 is an explanatory cross-sectional view of a slab using a conventional form panel-concrete panel.

FIG. 6 is an explanatory sectional view of a slab using a conventional concrete panel that also serves as a formwork.

[Explanation of symbols]

 Reference Signs List 1 ordinary concrete layer 2 lightweight concrete layer 3 steel bar

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI E04G 9/02 E04B 2/86 601C (56) References JP-A-61-274027 (JP, A) JP-A-2-25304 ( JP, A) JP-A-54-105128 (JP, A) JP-A-63-11306 (JP, A) JP-A-61-274028 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B28B 7/00 B28B 23/02 B32B 13/02 E04G 9/02 E04B 2/86

Claims (4)

(57) [Claims] 1. An ordinary concrete layer comprising cement, water and aggregate, and having an air-dry density of 0.9 to 1.7 g / c.
concrete panel ing from lightweight concrete layer of m ³
The ordinary concrete layer has a reinforcing bar embedded therein, and the lightweight concrete layer includes cement, water,
And synthetic resin foam beads having an average particle size of 0.1 to 1.5 mm
And the water-cement ratio is 45% or less, and
The mixing ratio of synthetic resin expanded beads is 10 to 55% by volume.
In addition, the lightweight concrete layer
Formwork combined concrete panels cured what further includes a cleat aggregate characterized Rukoto such by. Wherein said lightweight concrete layer, further comprises a finely pulverized product of vinyl chloride or chlorinated vinyl chloride resin foam according to claim 1 formwork combined concrete panel according. 3. The lightweight concrete layer has a length of 1-3.
Further comprising Claim 1 formwork combined concrete panel according to 0mm fiber. 4. A reinforcing bar is arranged at a predetermined position in a panel formwork.
And cement, water and aggregates in the formwork.
Casting ordinary concrete, and
Before the REIT cures, the cement, water and synthetic resin
Casting lightweight concrete made of foam beads
A method for producing a formwork-concrete panel, comprising:
The average particle size of synthetic resin expanded beads is 0.1-1.5mm
Yes, the water cement ratio is 45% or less, and
When the mixing ratio of the synthetic resin expanded beads is 10 to 55% by volume
In both cases, the lightweight concrete for structural
Of concrete panels that also contain formwork
Manufacturing method.