JP5905701B2 - Contaminated laying material treatment method - Google Patents

Description

  Techniques relating to processing when laying materials such as crushed stones laid on parking lots and promenades are contaminated with harmful substances are disclosed below.

  The demolition waste generated at the time of building demolition is classified by type due to the increasing awareness of recycling, and part of it is recycled into recycled crushed stones for use as roadbed materials. This reclaimed crushed stone is often laid instead of pavement as recycled gravel that forms surface layers such as parking lots and promenades, in addition to its use as a roadbed material for asphalt and concrete pavement as a laying material (for example, Patent Document 1). reference).

  With regard to laying materials laid in facilities such as parking lots, promenades, parks, etc., it has recently been discovered that asbestos-containing materials may be mixed in the reclaimed crushed stones and requests for countermeasures. The voice is rising (Non-Patent Document 1).

JP 2008-301732 A

"Asbestos found one after another at construction sites and parking lots", ECO JAPAN, http://eco.nikkeibp.co.jp/article/report/20100901/104685/, October 25, 2010 search

  In an existing facility, in order to treat asbestos-containing materials mixed in laying materials such as recycled crushed stone, measures to prevent asbestos scattering to the surrounding environment are necessary. That is, simply collecting and transporting recycled crushed stone mixed with asbestos-containing materials without taking any countermeasures may cause asbestos scattering to the surrounding environment during the scraping work, and the construction cannot be carried out. However, since there is no processing method that has taken effective measures at the present time, the present invention proposes a processing method suitable for processing such existing asbestos-containing material mixed recycled crushed stone.

The following two are proposed as methods for treating contaminated laying materials for the above problems.
One is a step of spraying a cement-based solidifying agent on a construction site where regenerated crushed stone mixed with asbestos-containing material is laid , a step of stirring the construction site after spraying the cement-based solidifying agent to a predetermined depth, Contamination laying material, comprising: curing the construction site after stirring to make concrete ; and cutting the construction site after curing into a predetermined shape and carrying out the concrete block formed by the cutting. It is a processing method.
The other is a process of spraying cement milk to a construction site where regenerated crushed stone mixed with asbestos-containing material is laid , curing and converting to concrete, and cutting the construction site after curing into a predetermined shape, And a step of carrying out the concrete block formed by the cutting .

  According to the method for treating contaminated laying material according to the above proposal, the cemented solidifying agent is used to transport the contaminated laying material after it has been made into concrete. It is possible to carry out removal work for laying materials.

Explanatory drawing of 1st Embodiment of a contamination-laying material processing method. Explanatory drawing explaining the process following FIG. Explanatory drawing of 2nd Embodiment of a contamination-laying material processing method. Explanatory drawing of 3rd Embodiment of a contamination-laying material processing method.

1 and 2 show a first embodiment of the contaminated laying material treatment method.
First, at the time of construction, in a facility where a laying material such as recycled crushed stone is laid as a surface layer on the road floor such as a parking lot or a promenade, the construction site is covered with the tent 1 to be isolated from the surrounding environment. The construction site may be part or all of the facility where the recycled crushed stone mixed with asbestos-containing material is laid as an example of the contaminated laying material. The tent 1 has a size of about 15 m × 15 m, for example, and the material of the sheet 1 a can be, for example, a polyethylene sheet or a poly film of 0.2 mm.

  The inner space of the sheet 1a of the tent 1 is maintained at a negative pressure by the negative pressure dust removing device 2 provided with a HEPA filter. Maintaining the inside of the tent 1 at a negative pressure makes it difficult for dust and pollutants flying inside to leak out of the tent 1. In addition, one or more mist devices 3 for spraying water in a mist form are installed inside the sheet 1a, and the construction of the mist while spraying water in the construction space suppresses the rising of dust and pollutants. The

  In the mist spraying atmosphere in the tent 1 having a negative pressure inside as described above, a treatment process for recycled crushed stone (contaminated laying material in the present embodiment) mixed with asbestos-containing material is performed.

  First, as a pretreatment prior to the application of the cement-based solidifying agent, although not essential, an asbestos wetting agent (a pollutant wetting agent that is selected according to the type of pollutant) is sprayed onto the construction site. As a precaution, asbestos scattering is more reliably suppressed by spraying the asbestos wetting agent. As an asbestos wetting agent, for example, AB200 (a product of Top Planning JAPAN Co., Ltd.) can be used. The asbestos wetting agent is sprayed by a worker using a sprayer or by a work vehicle equipped with a spraying device.

  Subsequently, a cement-based solidifying agent is sprayed on the construction site after the asbestos wetting agent is sprayed. Wet cement or sludge mortar can be used as the cement-based solidifying agent to be dispersed. Both of them have the characteristics that dust (cement dust) does not rise easily during construction, and is excellent in workability. For example, spraying of wet cement is performed by a dedicated spraying vehicle 4. The spray vehicle 4 is equipped with a tank and a device for mixing cement and a predetermined amount of water, and sprays while forming wet cement.

  And the stabilizer 5 is run as a stirring device at a certain distance so as to follow the spraying vehicle 4, and the construction place after the cement-based solidifying agent spraying is stirred to a predetermined depth. The depth of stirring may be about the depth of the surface layer in which the reclaimed crushed stone is spread as a laying material. For example, as shown in FIG. 1B, the depth of about 10 to 15 cm of the lower road bed on which the reclaimed crushed stone is laid. The stabilizer 5 is preferably dug up and stirred together with the regenerated crushed stones thereon. By removing the parts directly under the reclaimed crushed stone that cannot be said to be contaminated with asbestos, the certainty of the construction is improved. The stabilizer 5 for digging up has a structure in which a digging and raising device for attaching and rotating a bit around the drum is provided at the rear part of the traveling vehicle. It is assumed that it is covered with a dustproof film 5a. With this structure, scattering of cement dust and asbestos is suppressed. Furthermore, it is more preferable that the inner space of the dustproof film 5a is kept at a negative pressure by a negative pressure dust removing device 5b indicated by a dotted line. In addition to a large machine such as the stabilizer 5, an agricultural tractor or a tiller can be used as the stirring device. In these cases as well, it is preferable to take measures to cover the machined portion of the digging with a dust-proof film.

  The construction place where the stirring by the stabilizer 5 is finished is compacted and cured by the road roller 6. Thereby, the concrete which uses recycled crushed stone as the main aggregate is formed. After curing, cutting with the load cutter 7 is carried out. Before the cutting, asbestos solidifying agent (contaminant solidifying agent, depending on the type of pollutant, is used to suppress asbestos scattering more reliably. It is better to spray the selected drug) on the construction site. As a solidifying agent for asbestos, for example, AB100 (a product of Top Planning JAPAN Co., Ltd.) can be used. The asbestos solidifying agent is sprayed by a worker using a sprayer or by a work vehicle equipped with a spraying device. After spraying the asbestos solidifying agent, the construction site is cut into a predetermined shape suitable for carrying out using the load cutter 7 and the cut pieces are carried out.

  Dispose the cut pieces (concrete blocks) according to the specified procedure. The construction site after unloading will be finished by dismantling the tent, leveling new crushed stone, and rolling.

A second embodiment of the contaminated laying material processing method will be described with reference to FIG.
The second embodiment is an example in which sludge mortar is used as a cement-based solidifying agent. In the case of the second embodiment, similarly to the first embodiment, construction is carried out while water is mist-sprayed from the mist device 3 inside the construction site covered with the tent 1, and sludge mortar is used as a cement-based solidifying agent. The method other than spraying is the same as in the first embodiment.

  Since sludge mortar mixed with sludge has high fluidity, it can be sprayed from the outside of the tent 1 to the construction site by using the mixer truck 10 and the pump device 11 without using the spraying vehicle 4. . The transport pipe 11a extending from the pump device 11 passes through the sheet 1a of the tent 1 and faces the construction site, and the sludge mortar is pumped and sprayed over the entire construction site. Since the mixer truck 10 and the pump device 11 are outside the tent 1 and are not exposed to the contaminants, it is possible to save the trouble of cleaning after construction. Note that a pump vehicle (boom vehicle) may be used instead of the pump device 11.

A third embodiment of the contaminated laying material processing method will be described with reference to FIG.
The third embodiment is an example using cement milk having high permeability. In the case of the third embodiment, similarly to the first embodiment, the construction is carried out while water is mist-dispersed from the mist device 3 inside the construction place covered with the tent 1.

  First, as in the first embodiment, as a pretreatment prior to the application of cement milk, an asbestos wetting agent (contaminant wetting agent) is applied to the construction site in order to more reliably suppress the scattering of asbestos, which is a contaminant. In the case of this example, the asbestos wetting agent is sprayed by a spraying vehicle 20 equipped with a spraying device.

  Subsequently, the cement milk is sprayed on the construction site after the asbestos wetting agent is sprayed. Since the cement milk has high fluidity, it can be sprayed from the outside of the tent 1 to the construction site using the mixer truck 10 and the pump device 11 as in the second embodiment. The transport pipe 11a extending from the pump device 11 penetrates the sheet 1a of the tent 1 and faces the construction site, and the cement milk is pumped and sprayed over the entire construction site. Since the mixer truck 10 and the pump device 11 are outside the tent 1 and are not exposed to the contaminants, it is possible to save the trouble of cleaning after construction.

  After the cement milk is poured into the construction site, it is cured. In curing, the road roller 6 may be compacted as in the first embodiment, or the recycled crushed stone as the laying material is originally compacted, and may be cured as it is. Due to the permeability of the cement milk, the cement milk penetrates the entire surface layer where the reclaimed crushed stone is present, and concrete with the reclaimed crushed stone as the main aggregate is formed.

  As with the first embodiment, after curing, cutting with the load cutter 7 is carried out. Before the cutting, asbestos solidifying agent (pollutant solidifying agent) is used to more reliably suppress the scattering of asbestos, which is a pollutant. It is better to spray it on the construction site. After spraying the asbestos solidifying agent, the construction site is cut into a predetermined shape suitable for carrying out using the load cutter 7 and the cut pieces are carried out.

  Dispose the cut pieces (concrete blocks) according to the specified procedure. After carrying out the cut piece, in the case of this example, the exposed surface of the construction site is shaved to a predetermined depth. For example, for the same reason as described with reference to FIG. 1B, it is preferable to scrape the exposed roadbed to a depth of about 10 to 15 cm. In addition, there is a possibility that the spread cement milk may penetrate to the roadbed. In this case, the roadbed where the cement milk penetrated is also peeled off as a part of the cut piece, so that the process may be unnecessary. The construction site after this will be finished by dismantling the tent, leveling new crushed stones, and rolling.

  According to each of the embodiments described above, since the processing method for transporting the contaminated laying material after concretely converting the contaminated laying material into a concrete with a cement-based solidifying agent such as wet cement, sludge cement, or cement milk, the scattering of pollutants to the periphery. It is possible to carry out the removal work of the contaminated laying material while preventing this. In the above description, asbestos has been described as a specific example of the contaminant, but the contaminant is not limited to asbestos. For example, the present invention is also effective in the case of an existing facility contaminated with radioactive substances or other harmful substances.

DESCRIPTION OF SYMBOLS 1 Tent 2 Negative pressure dust removal device 3 Mist device 4 Scattering vehicle 5 Stabilizer 6 Road roller 7 Load cutter 10 Mixer car 11 Pump car 20 Scattering vehicle

Claims (9)

A process of spraying a cement-based solidifying agent to a construction site where recycled crushed stone mixed with asbestos-containing material is laid ,
A step of stirring the construction place after spraying the cement-based solidifying agent to a predetermined depth;
Curing the construction site after the stirring and converting it into concrete ;
Cutting the construction site after curing into a predetermined shape, and carrying out a concrete block formed by the cutting ;
Contamination laying material processing method including. The contaminated laying material treatment method according to claim 1, further comprising a step of spraying an asbestos wetting agent to the construction site before the step of spraying the cement-based solidifying agent. The contaminated laying material processing method according to claim 1 or 2, further comprising a step of spraying an asbestos solidifying agent on the post-curing construction site before the step of cutting the post-curing construction site. Spraying cement milk on the construction site where the recycled crushed stone mixed with asbestos-containing material is laid , curing and converting to concrete ,
Cutting the construction site after curing into a predetermined shape, and carrying out a concrete block formed by the cutting ;
Contamination laying material processing method including. The contaminated laying material processing method according to claim 4, further comprising a step of spraying an asbestos wetting agent to the construction site before the step of pouring the cement milk. The contaminated laying material processing method according to claim 4 or 5, further comprising a step of spraying an asbestos solidifying agent on the post-curing construction site before the step of cutting the post-curing construction site. Wherein after the step of unloading the concrete block, further comprising the step of scraping the exposed surface of a predetermined depth of the working place, contaminated laying material processing method according to any one of claims 4-6. Wherein each step is construction in the mist atmosphere due to water mist spraying to construction space above the working place, contaminated laying material processing method according to any one of claims 1-7. Wherein each step, the working place for the construction in the negative pressure the tent covered with tent, pollution laying material processing method according to any one of claims 1-8.

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