JP2002053354A - Aggregate for concrete, production process of the same, formwork for precast concrete and precast concrete formed plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide concrete aggregate which is made of a synthetic resin and has easily attainable good and stable affinity for cement and enables inhibition of any remarkable reduction in strength of concrete from being caused. SOLUTION: This aggregate is a synthetic resin granular material containing at least either lime or cement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete aggregate using a synthetic resin, a method for producing the same, a precast concrete formwork made of concrete containing the aggregate, and a precast concrete molded plate.

[0002]

2. Description of the Related Art Conventionally, effective use of waste synthetic resin products and
In order to reduce the weight of concrete, waste thermoplastic synthetic resin is cut into small pieces, heated to a temperature above the softening temperature, and then cement-affinity material (fly ash) is brought into contact with the material and used as the aggregate for concrete. This is known (Japanese Patent Laid-Open No. Hei 10-245251). Further, in order to reduce the weight of the obtained concrete, it is also known to use a composite of a plurality of synthetic resin foams which are hardened and integrated with a hydraulic binder (cement) as an aggregate for concrete (Japanese Unexamined Patent Publication (Kokai) No. Heisei (Kokai) No. Hei 10 (1994) -181868. 7-277855).

[0003]

However, in a conventional concrete aggregate having a cement-affinitive material fixed on the surface, if the cement-affinitive material is not adhered to the aggregate, the aggregate and the concrete become less compatible with each other. There is a gap between the concrete, which makes it easier for rainwater to enter or cracks. For this reason, the cement-affinitive material must be firmly fixed on the surface of the small piece of the synthetic resin so as not to fall off, and the production is troublesome and there is a problem of low productivity. Conventional concrete aggregates using synthetic resin foam have a surface covered with a hardened material of a hydraulic material amount, but the core is a fragile synthetic resin foam. There is a problem that the drop is large.

The present invention has been made in view of such conventional problems, and a synthetic resin concrete which can easily obtain good and stable affinity with cement and does not cause a large decrease in strength of the concrete. An object of the present invention is to provide an aggregate for use and a method for producing the same, and to provide a precast concrete formwork and a precast concrete molded plate made of concrete containing the aggregate.

[0005]

In order to achieve the above object, a first object of the present invention is to provide a concrete aggregate characterized by being a synthetic resin granule containing one or both of lime and cement. Is provided.

[0006] The first aspect of the present invention is that one or both of lime and cement are mixed in an amount of 30 to 70 parts by weight with respect to 100 parts by weight of the synthetic resin. , A waste synthetic resin, one or both of lime and cement, or part or all of it, is a crushed concrete, a part or all of synthetic resin, and one or both of lime and cement Part or all of the above is a pulverized product of concrete containing any of the above concrete aggregates as a preferred embodiment thereof.

A second aspect of the present invention is to mix one or both of lime and cement with a molten synthetic resin,
The present invention provides a method for producing an aggregate for concrete, comprising extruding the mixture into a rod shape and cutting the mixture into an appropriate length.

[0008] The second aspect of the present invention is to mix one or both of lime and cement with 30 to 70 parts by weight with respect to 100 parts by weight of synthetic resin. Using resin, using crushed concrete for part or all of lime and cement, or part of both, part or all of synthetic resin, and part of either or both of lime and cement Or as a whole, using a crushed concrete containing concrete aggregate produced by any one of the above production methods,
Is included as a preferred embodiment.

A third aspect of the present invention is characterized in that a corrugated steel sheet having a wire mesh welded to one side thereof is provided with a concrete layer containing any of the above-mentioned concrete aggregates on the wire mesh welded surface side. It provides a precast concrete formwork.

A fourth feature of the present invention is that a concrete layer containing any of the above-mentioned concrete aggregates is formed on the wire mesh welding surface side of the corrugated steel sheet having a wire mesh welded on one surface. And a precast concrete molded plate.

A fourth aspect of the present invention is that a wire mesh is also welded to the other surface of the corrugated steel sheet, and the wire mesh welding surface on the other surface is also welded.
It is preferable that the concrete layer containing the aggregate for concrete according to any one of claims 1 to 5 is formed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a concrete aggregate according to the present invention and a method for producing the same will be described.

As the synthetic resin constituting the concrete aggregate of the present invention, general thermoplastic resins can be widely used. Specifically, polyethylene, polypropylene,
Polystyrene, vinyl chloride, ABS resin, PET, etc.
Can be used widely. In addition, one of these may be used, but if it is compatible or a polymer alloy (a combination that does not cause phase separation), it may be composed of a mixture of a plurality of types of synthetic resins. .

The concrete aggregate of the present invention contains either lime and cement (usually Portland cement) or both based on the above synthetic resin. The lime and the cement are used for imparting affinity to the concrete for the concrete aggregate and for hardening the concrete aggregate to prevent a large decrease in the strength of the obtained concrete product.
It is preferably contained in an amount of 30 to 70 parts by weight based on 0 part by weight. Either lime or cement may be used, or both may be used, but lime is preferred because the resulting concrete aggregate is lightweight.

The concrete aggregate of the present invention comprises the above-mentioned synthetic resin and lime and / or cement as main materials, and the main material is preferably 80% by weight or more. The aggregate for concrete of the present invention can contain a material other than the above-mentioned main material in the range of 20% by weight or less. Other materials such as glass fiber,
In addition to fillers used in general synthetic resin products such as carbon fiber and talc, sand and the like can be mentioned.

As the synthetic resin constituting the concrete aggregate of the present invention, a waste synthetic resin can be used, and the waste synthetic resin can be recycled. This waste synthetic resin will be described later.

In addition, crushed concrete can be used as part or all of the lime and / or cement constituting the aggregate for concrete of the present invention. As the crushed concrete, a crushed concrete using common sand or gravel as an aggregate can be used. When using the crushed concrete of the general sand or gravel as an aggregate, a part of lime and / or cement (preferably 70% by weight) is used in view of maintaining the quality of the obtained concrete aggregate. (The following range).

Further, a crushed concrete containing the concrete aggregate of the present invention can be used as a synthetic resin constituting the aggregate for concrete of the present invention and a part or all of lime and / or cement. . Also in this case, for the same reason as above, a part of the synthetic resin and lime and / or cement used (preferably in a range of 70% by weight or less).
It is preferable to use them.

The concrete aggregate of the present invention is in the form of granules, and may have any shape such as a sphere, an oval sphere, a prism, and a cylinder.
A cylindrical shape is preferred. In the case of this cylindrical shape, the diameter is 1 to
10 mm, preferably 2-25 mm in length,
More preferably, the diameter is 3 to 8 mm and the length is 5 to 15 mm
It is.

In the concrete aggregate of the present invention, the synthetic resin is melted, and either or both of lime and cement are added and mixed, and this mixture is extruded into a rod (linear) to have an appropriate length. It can be easily manufactured by cutting. Specifically, using a synthetic resin extruder, the molten resin and lime and / or cement are mixed and kneaded in the extruder, and the mixture is extruded into a rod shape. It can be easily manufactured by cutting into length and cooling and hardening.

The amount of lime and / or cement added is
As described above, 30 to 70 parts by weight based on 100 parts by weight of the synthetic resin.
It is preferably in parts by weight. If the added amount of lime and / or cement is too small, the affinity of the obtained concrete aggregate with the cement tends to be insufficient, and if too large, the obtained concrete aggregate tends to become brittle.

As the synthetic resin used for the production of the concrete aggregate, waste synthetic resin is most suitably used.
By using the waste synthetic resin, not only can the material cost be reduced, but also the waste synthetic resin can be recycled. Examples of the waste synthetic resin include waste of a synthetic resin sheet used in an agricultural house, a synthetic resin housing of a waste electric product (for example, a computer or a television), a plastic bottle, and a synthetic resin discharged when dismantling an automobile. Examples include interior materials, styrofoam waste buffer materials and waste fish boxes. These are pulverized and used as raw materials for the concrete aggregate.

Further, as a raw material of the concrete aggregate of the present invention, concrete using general sand or gravel as an aggregate,
Concrete including the present concrete aggregate can also be used. More specifically, concrete containing sand or gravel or concrete containing the aggregate for concrete is crushed, and if necessary, synthetic resin and lime and / or cement are separately added and melt-kneaded, It can be recycled as concrete aggregate again. By doing so, the amount of waste at the time of dismantling the concrete structure can be reduced, and the amount of synthetic resin, lime, and / or cement newly prepared at the time of manufacturing the concrete aggregate can be reduced.

The concrete aggregate of the present invention is used by mixing it with cement together with water instead of sand or gravel generally used as concrete aggregate. When the concrete aggregate of the present invention is used, the amount of cement (usually Portland cement), the concrete aggregate, and water is the same as in the case of using sand or gravel as the aggregate, and is based on 100 parts by weight of cement. Preferably, the aggregate for concrete is 400 to 450 parts by weight and the water is 40 to 50 parts by weight.

Next, a precast concrete formwork of the present invention composed of concrete containing the above-mentioned concrete aggregate will be described.

As shown in FIGS. 1 and 2, the precast concrete formwork of the present invention has the above-described concrete aggregate on the welded side of the wire mesh 1 of a corrugated steel plate 2 having a wire mesh 1 welded to one side. The concrete layer 3 to be contained is formed.

The corrugated steel sheet 2 functions as a reinforcing member for the precast concrete formwork, and is particularly unlikely to bend in the longitudinal direction of the irregularities. For example, the preform concrete formwork warps in this direction during transportation or installation work. Thus, the concrete layer 3 is prevented from peeling or cracking. The wire mesh 1 also functions as a reinforcing member.
Of the corrugated steel sheet 2 is hardly deflected in the direction in which the irregularities are arranged in parallel, and the warp of the precast concrete formwork in this direction can be suppressed.

Particularly, in the precast concrete formwork of the present invention, the concrete layer 3 contains the concrete aggregate of the present invention. For this reason, the precast concrete form can be reduced in weight as compared with a case where sand or gravel is used as an aggregate of the concrete layer 3, and has an advantage that it is excellent in handling during construction.

More specifically, the cross-sectional shape of the concave and convex portions of the corrugated steel sheet 2 may be, for example, a trapezoidal shape, a triangular shape, or the like, in addition to the illustrated rectangular shape. In particular, it is preferable that the cross section has an inverted trapezoidal shape (a trapezoidal shape in which the bottom side of the convex portion is longer than the top side length) because the corrugated steel sheet 2 and the concrete layer 3 mesh with each other and are firmly integrated.

The corrugated steel sheet 2 has irregularities with a depth (height) of 5 to 15 mm and a pitch of 100 to 250 mm.
It is preferred that it is about.

As the wire netting 1, a steel wire having a diameter of about 2 to 4 mm arranged in a grid and intersections welded can be used.

In the precast concrete formwork of the present invention, concrete using the concrete aggregate of the present invention is poured into a molding die, and a corrugated steel sheet 2 with a wire mesh 1 is placed on the concrete. It can be easily manufactured by covering and pressing down with the welding surface side facing inward.

The precast concrete formwork is 25
When manufactured as a thin product having a thickness of about 40 mm, the concrete layer 3 using the concrete aggregate of the present invention can be made lightweight and easy to handle.

The precast concrete formwork is assembled into a formwork with the corrugated steel sheet 2 side facing inward, and concrete (concrete using ordinary sand or gravel as an aggregate) is assembled in the assembled formwork. It is used as a discarded formwork that is cast as a concrete structure and then left as a part of the concrete structure. That is, the outer surface of the constructed concrete structure is constituted by the concrete layer 3 of the present precast concrete formwork. The concrete layer containing the concrete aggregate of the present invention is mainly composed of a synthetic resin having almost no water absorption, and a concrete aggregate having a good affinity for cement is present in close contact with the cement.
The water absorption of the obtained concrete structure can be suppressed.

In the precast concrete formwork of the present invention, a structural reinforcing bar of the concrete structure to be constructed is previously welded to the opposite side of the corrugated steel sheet 2 to the welding surface of the wire mesh 1 (the inner side when the formwork is assembled). You can also. By welding the reinforcing steel for the structure in advance, the work of arranging the reinforcing steel on site can be reduced.

The same precast concrete product as described in FIGS. 1 and 2 is used instead of the above-mentioned formwork.
It may be a precast concrete molded plate constituting a non-physical wall such as an outer wall of a building, a partition, a ceiling, or the like.

For example, if the precast concrete molded plate has the structure shown in FIG. 1 and is fixed to the outer surface of the outer wall of the building with the exposed surface of the corrugated steel plate 2 inside, it is fixed with a mortar dumpling or a fixture. , Can be used as an outer wall material. In this case, a heat insulating material, a sound insulating material and the like can be interposed between the precast concrete molded plate and the outer wall of the building.

Further, the precast concrete molded plate has the structure shown in FIG. 1, and two corrugated steel plates 2 are faced to each other with the exposed surface of the corrugated steel plate 2 facing inward, and partially joined with a mortar dumpling or a fixing bracket. In this case, a heat insulating material, a sound insulating material, or the like may be interposed therebetween to be used as a wall or ceiling panel. Further, a plate material such as a gypsum board, a plywood or the like is joined to the exposed surface side of the corrugated steel sheet 2 of one precast concrete molded product with a mortar dumpling or an adhesive, and a heat insulating material or a sound insulating material is interposed as necessary. Can be sandwiched to form a wall or ceiling panel.

In the case of the composite panel as described above, the total thickness is set to 30 in order to make the whole lightweight and easy to handle.
It is preferably about 200 mm. In addition, by utilizing the gap between the precast concrete molded plates in the composite panel, the composite panel can be used as electric wiring, water supply and sewerage, and other piping space.

In addition to the above, a wire mesh similar to the wire mesh 1 provided on one side is provided on the exposed surface side of the corrugated steel sheet 2 of the precast concrete product having the structure shown in FIG. In addition, a concrete layer containing the aggregate for concrete of the present invention (a layer similar to the layer indicated by reference numeral 3 in FIG. 1) may be provided. in this case,
Since the wire mesh 1 is welded to both sides of the corrugated steel sheet 2, the strength can be improved.

When the concrete layers 3 are provided on both sides of the corrugated steel sheet 2 as described above, the pitch of the concavities and convexities is the same as described above, but the depth (height) of the corrugated steel sheet 2 is 30 to 100.
mm. In the precast concrete molded plate provided with the concrete layers 3 on both sides, the concrete using the concrete aggregate of the present invention was poured into a formwork, and the wire mesh 1 was welded to both sides of the concrete from above. The corrugated steel plate 2 is covered, pressed down and blended in. After the concrete is hardened, it is inverted and the corrugated steel plate 2
It can be easily manufactured by pouring and hardening the same concrete on the opposite surface side of.

[0042]

The present invention has been described above, and has the following effects.

(1) The concrete aggregate of the present invention is made of lime and / or cement mixed with a synthetic resin.
Since the affinity with the cement can be obtained, the affinity with the cement is hardly uneven, and the affinity does not decrease due to vibration due to storage or transportation or aging.

(2) Since the concrete aggregate of the present invention is a hard body using a non-foamed synthetic resin, it is possible to suppress a decrease in the strength of the obtained concrete.

(3) For example, it can be easily manufactured by molding into a pellet by an extruder, and the productivity is good.

(4) The precast concrete formwork of the present invention and the precast concrete molded plate of the present invention
Concrete layer 3 using aggregate for concrete of the present invention
Therefore, it is lighter than the concrete layer 3 using sand or gravel as an aggregate, and is excellent in handleability.

(5) The concrete layer 3 containing the concrete aggregate of the present invention contains a synthetic resin having almost no water absorption as a main component, and the concrete aggregate having a good affinity for the cement is in close contact with the cement. Because it exists
Water absorption can be suppressed. Therefore, with regard to the precast concrete formwork of the present invention, when the corrugated steel sheet 2 side is set to the inside and the waste formwork is used, it is possible to suppress the water absorption of the obtained concrete structure. Further, the precast concrete molded plate is excellent in waterproof performance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a precast concrete formwork (precast concrete molded plate) according to the present invention.

FIG. 2 is a perspective view of a corrugated steel sheet with a wire mesh of the precast concrete formwork (precast concrete molded board) shown in FIG.

[Description of Signs] 1 Wire mesh 2 Corrugated steel plate 3 Concrete layer

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Claims (13)

[Claims] An aggregate for concrete, characterized in that it is a synthetic resin granule containing one or both of lime and cement. 2. The amount of one or both of lime and cement is 30 to 70 parts by weight based on 100 parts by weight of synthetic resin.
The aggregate for concrete according to claim 1, which is a weight part. 3. The concrete aggregate according to claim 1, wherein a part or all of the synthetic resin is a waste synthetic resin. 4. The concrete aggregate according to claim 1, wherein one or both of the lime and the cement or a part or all of the lime and the cement are crushed concrete. 5. A concrete containing the aggregate for concrete according to any one of claims 1 to 4, wherein a part or all of the synthetic resin and a part or all of one or both of the lime and the cement. Aggregate for concrete, characterized by being a crushed product of: 6. A method for producing an aggregate for concrete, comprising mixing one or both of lime and cement with a molten synthetic resin, extruding the mixture into a rod shape, and cutting the mixture into appropriate lengths. . 7. The method for producing an aggregate for concrete according to claim 6, wherein one or both of lime and cement are mixed in an amount of 30 to 70 parts by weight with respect to 100 parts by weight of the synthetic resin. 8. The method for producing an aggregate for concrete according to claim 6, wherein a waste synthetic resin is used for part or all of the synthetic resin. 9. The method for producing an aggregate for concrete according to claim 6, wherein a crushed material of concrete is used for part or all of one or both of lime and cement. . 10. As part or all of a synthetic resin and one or both of lime and cement,
A method for producing a concrete aggregate, comprising using a crushed concrete containing the concrete aggregate produced by the production method according to claim 6. 11. A corrugated steel sheet to which a wire mesh is welded on one side, wherein a concrete layer containing the concrete aggregate according to any one of claims 1 to 5 is formed on the wire mesh welding surface side. And precast concrete formwork. 12. A corrugated steel sheet having a wire mesh welded to one side thereof, wherein a concrete layer containing the concrete aggregate according to any one of claims 1 to 5 is formed on the wire mesh welded surface side. Precast concrete molded board. 13. A concrete layer containing the aggregate for concrete according to any one of claims 1 to 5, wherein a wire mesh is welded to the other surface of the corrugated steel sheet, and the wire mesh welding surface on the other surface is also welded. A precast concrete molded plate, characterized in that is formed.