JP4811732B2 - Cement solidification method for asbestos waste - Google Patents

Description

  The present invention relates to a cement solidification method for asbestos waste.

Conventionally, waste containing asbestos (including waste asbestos) (hereinafter referred to as asbestos waste) is double-packed in plastic bags and disposed of in landfills at predetermined disposal sites. In particular, when landfilling at a disposal site in Tokyo, it is obliged to landfill in the following manner. As disposal procedures in Tokyo, (1) solidify asbestos waste with cement, etc. to make it difficult to disperse, (2) solid waste (hereinafter referred to as solidified) manually. (3) Set the uniaxial compressive strength of the solidified body to 10 kg / cm ² (1 N / mm ² ) or more, (4) Double-pack the solidified body with a plastic bag, That's it. In addition, Tokyo introduces a blending example of asbestos waste: cement: water = 1: 2: 3 (hereinafter referred to as “Tokyo blending”) as a reference example of blending at the time of solidification.

On the other hand, in recent years, a technique for solidifying asbestos waste by reducing the mass ratio of cement has been proposed. This method is a technique for reducing the mass ratio of cement by adding an additive such as a high-performance water reducing agent or a fluidizing agent. Specifically, asbestos waste: cement: water = 10: 8 to 12 : A method of kneading at a blending ratio of 6 to 8 (see, for example, Patent Document 1).
Japanese Patent No. 2719629

  However, in the method of solidifying asbestos waste with the above-mentioned composition, the amount of asbestos waste contained in the solidified material is small (the content of asbestos waste = about 17% by mass), which increases the cost. There is a problem of doing. Explaining in detail, costs for solidifying asbestos waste mainly include “material costs such as cement” and “production costs of solidified bodies (personnel costs, etc.)”. If the content of asbestos waste contained in the solidified body is small, the amount of cement per solidified body increases accordingly, and the above-mentioned material cost increases. In addition, since the amount of asbestos waste to be disposed of is determined, if the amount of asbestos waste contained in the solidified body is small, the amount of solidified body increases accordingly, and the above-mentioned material costs and production costs increase. . Therefore, in the above-mentioned capital blending with a low content of asbestos waste, the material cost and the production cost for solidifying the asbestos waste become high.

  In addition, in the conventional technology with a reduced cement mass ratio, the kneaded mixed material has a problem that it becomes a solidified body that is brittle and easily collapsed because it has a very low moisture content and is in a damp and sandy state. . If the solidified body collapses, there arises a problem that asbestos fibers contained therein are scattered.

  The present invention takes the above-mentioned conventional problems into consideration, can reduce the cost when solidifying asbestos waste, and can produce a solidified body having a property that does not easily collapse. The object is to provide a method for solidifying cement in waste.

The method for solidifying cement of asbestos waste according to the present invention is a cement solidification method for asbestos waste in which asbestos waste containing asbestos is solidified with cement. Asbestos waste, cement, water, and additive A kneading step of mixing 1 to 3 parts by weight of asbestos waste and 1 to 2 parts by weight of water with respect to 1 part by weight of cement, filling the kneaded mixed material into a mold and fastening A solidified body of the mixed material after the molding step with a specific gravity at the time of molding the test piece, and confirming the specific gravity and compressive strength with a test piece prepared in advance with the mixed material It is characterized by managing the compression strength .

  Due to such characteristics, the content of asbestos waste in the finished solidified body is 30% or more by mass ratio. Further, since the mixed material is compacted during the molding process, a solidified solidified body is completed.

  Further, in the cement solidification method for asbestos waste according to the present invention, the kneading step mixes cement, water and additives to produce cement milk, and then kneads the cement milk and asbestos waste. The step of mixing is preferable.

  Thereby, in the kneading process, asbestos waste, cement, and the like are mixed evenly without being biased.

  According to the cement solidification method of asbestos waste according to the present invention, the content of asbestos waste contained in the solidified body can be increased, and accordingly, a material such as cement for producing the solidified body. Costs and production costs can be reduced, and costs can be reduced. Moreover, since the completed solidified body is solidified firmly, the danger that a solidified body will collapse | crumble and an asbestos fiber will be scattered can be suppressed.

  Hereinafter, embodiments of the cement solidification method of asbestos waste according to the present invention will be described with reference to the drawings. FIG. 1 is a flowchart showing the disposal process of asbestos waste.

[Asbestos removal work]
First, as shown in FIG. 1, the operation | work which removes the asbestos containing building materials provided in the existing building etc. is performed. The asbestos-containing building material can be removed by various methods. For example, when the asbestos-containing building material is sprayed on a steel frame or deck plate, the worker manually removes the asbestos-containing building material using a spatula. There is a way to scrape off.

[Cement solidification work]
Next, the removed asbestos-containing building material (asbestos waste) is solidified with cement. The cement solidification work is performed by the following method.

  First, a kneading process is performed in which asbestos waste, cement, water, and a small amount of additives are kneaded. More specifically, first, cement milk is prepared by mixing cement, water and additives with a mixer or the like. Next, asbestos waste is put into the produced cement milk, and further kneaded with a mixer or the like. As a result, asbestos waste, cement, water, and a small amount of additive are evenly mixed to knead the mixed material.

  Asbestos waste, cement, and water are mixed at a mixing ratio of 1 to 2.5 parts by weight of asbestos waste and 1 to 1.75 parts by weight of water with respect to 1 part by weight of cement. That is, the weight ratio of asbestos waste, cement, and water is expressed by the following equation.

In addition, it is more preferable to set the mixing ratio of 1 to 2.5 parts by weight of asbestos waste and 1 to 1.75 parts by weight of water with respect to 1 part by weight of cement.
In addition, the additive is a combination of an appropriate amount of an additive (such as a high-performance water reducing agent or a fluidizing agent) used in fresh concrete and an anti-dust scattering agent used when removing asbestos-containing building materials. . Moreover, as this additive, what does not contain any harmful thing is used.

  Next, after the kneaded mixed material is put into a bottomed cylindrical mold, it is compacted and molded. More specifically, as shown in FIG. 2A, the mixed material 2 is filled into the mold 1 using a scoop or the like. Thereafter, as shown in FIG. 2B, the mixed material 2 in the mold 1 is oscillated and compacted. For example, vibration compaction is performed using a machine provided with a compaction plate at the tip of a small rammer or breaker. Thereafter, after curing for a predetermined period, the solidified body 3 that has been compacted and solidified is extracted from the mold 1. For example, when the solidified body 3 is molded into a substantially cylindrical shape having a diameter of 20 cm and a height of 20 cm, the mass thereof is about 10 kg / piece.

In cement solidification work, the compressive strength of the solidified body 3 is managed. More specifically, a test piece is prepared by filling a general mold with a mixed material, and a compressive strength test is performed on the test piece based on JIS standards. At this time, since it is difficult to compact the test piece under the same conditions as the compaction at the time of solidified body creation, the relationship between the specific gravity and the compressive strength is confirmed beforehand by a test, and the test piece molding is performed. The compressive strength is managed by the specific gravity of time.
Through the above steps, the cement solidification work of asbestos waste is completed.

[Packing work]
Next, the produced solidified body 3 is packed twice in a plastic bag one by one. At this time, the mouth of the plastic bag containing the solidified body 3 is tied and closed.

[Reclaiming work]
Next, the packed solidified body 3 is placed on a transport vehicle, transported to a disposal site, and landed in the disposal site. The operation of loading the packed solid body 3 onto the loading platform of the transport vehicle and the operation of lowering the solidified body 3 on the loading platform and loading it on the disposal site are performed manually so that the plastic bag is not torn.
Through the above operations, disposal of asbestos waste is completed.

  According to the cement solidification method for asbestos waste having the above-described configuration, the content of asbestos waste in the solidified body 3 is 30% or more. Thus, since the content of asbestos waste contained in the solidified body 3 can be increased as compared with the case of the conventional capital blending, material costs such as cement for producing the solidified body 3 correspondingly. And production costs such as labor costs can be reduced.

Further, in the formulation of the above-described embodiment, the kneaded mixed material 2 is in a dry wet sand state, but since the mixed material 2 is compacted during the molding process, the solidified solidified body 3 is solidified. It ’s done. Thereby, the uniaxial compressive strength of the solidified body 3 becomes 1 N / mm ² or more, and the risk that the solidified body 3 is broken and asbestos fibers are scattered can be suppressed.
Moreover, since the solidified body 3 is molded by compaction, the content of asbestos waste is increased and the volume of the solidified body is reduced. As a result, a large amount of asbestos waste can be disposed of in a smaller disposal area, and the life of the disposal site can be extended.

  In addition, when the asbestos fibers are gathered in one place, the portion becomes brittle and easily collapses. However, according to the above-described cement solidification method of asbestos waste, the cement, water, and additives are mixed during the kneading process. Then, since the cement milk and the asbestos waste are kneaded and mixed, the asbestos waste and cement are hardly mixed and are mixed evenly. This makes it possible to produce a solidified body that is brittle and does not easily collapse.

  As mentioned above, although the embodiment of the cement solidification method of asbestos waste according to the present invention has been described, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof. It is. For example, in the above-described embodiment, cement milk is prepared in advance by mixing cement, water, and additives in the kneading step, and the cement milk and asbestos waste are kneaded. The invention can also change the timing of asbestos waste, cement, water and additives. For example, asbestos waste and cement can be first mixed with a mixer and mixed approximately evenly, and then water and additives can be added and mixed, or asbestos waste, cement and water can be mixed. It is possible to add and knead at the same time, and to add the additive at an appropriate timing, or it is possible to add all the ingredients at the same time and knead.

  Further, in the above-described embodiment, vibration compaction is performed on the mixed material filled in the mold to perform compaction, but the present invention is not limited to vibration compaction, for example, A pressure plate is set on the surface of the mixed material filled in the mold, and a predetermined load is loaded on the pressure plate for a predetermined time, so that the mixed material in the mold is compressed and compacted. May be.

  Moreover, in the above-described embodiment, a solidified body having a columnar shape is manufactured. However, in the present invention, the shape of the solidified body can be appropriately changed, and a solidified body having a prism shape or a square shape can also be manufactured. is there.

  In addition, in the range which does not deviate from the main point of this invention, it is possible to replace suitably the component in above-mentioned embodiment with a well-known component, and you may combine the above-mentioned modification suitably.

It is a flowchart figure for demonstrating embodiment of this invention. It is a fracture | rupture perspective view of the formwork with which the mixed material for demonstrating embodiment of this invention was filled.

Explanation of symbols

1 Form 2 Mixed material 3 Solidified body

Claims (2)

In the cement solidification method of asbestos waste in which asbestos waste containing asbestos is solidified with cement,
A kneading step in which asbestos waste, cement, water and additives are kneaded in a mixing ratio of 1 to 3 parts by weight of asbestos waste and 1 to 2 parts by weight of water with respect to 1 part by weight of cement;
A molding process in which the mixed material that has been kneaded is filled into a mold, compacted, and molded,
Equipped with a,
Asbestos, characterized in that specific gravity and compressive strength are confirmed with a test piece prepared in advance using the mixed material, and the compressive strength of the solidified material of the mixed material after the molding step is managed with the specific gravity at the time of molding the test piece. Cement solidification method for waste. In the cement solidification method of the asbestos waste according to claim 1,
Cement solidification of asbestos waste characterized in that the kneading step is a step of mixing cement, water and additives to produce cement milk, and then kneading the cement milk and asbestos waste Method.

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