JP3426936B2 - Method and apparatus for producing recycled aggregate - 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 and an apparatus for producing recycled aggregate from construction mud produced during construction work such as tunnel excavation.

[0002]

2. Description of the Related Art Construction mud generated by the construction of underground structures such as tunnels has conventionally been disposed of as industrial waste for a fee. In this case, not only the construction cost will rise, but also the shortage of land for disposal of residual soil and transportation costs will occur. In addition to such problems, it is considered that construction mud is used as recycled aggregate for concrete because of the problem of depletion of natural aggregate resources.

At present, as a technique for reusing construction mud, application to backfilling materials is being examined, but application to raw materials for concrete, which is also widely applicable as a construction material, is still not sufficient. Absent.

A processing flow of such a conventional construction mud is shown in FIG. Construction mud 1 generated at the site is gravel / sand component 2 (d ≧ 74 μm) with large particle size in the gravel / sand separation equipment 10.
After being collected, the silt / clay component 3 (d <74 μm) is collected in the solid-liquid separation facility 20. The gravel / sand component 2 is reused as a backfill material and the like, while the silt / clay component 3 is transported to a treatment site as industrial waste and disposed of.

[0005]

When manufacturing recycled aggregate for concrete from construction mud, strength and water absorption as recycled coarse aggregate and recycled fine aggregate specified by Japanese Industrial Standards, etc. It becomes a necessary condition to satisfy the quality of. Further, unless the cost of manufacturing recycled aggregate is lower than the cost of purchasing natural aggregate, the advantage of manufacturing recycled aggregate from construction mud will be diminished. Therefore, it must be possible to manufacture at a low cost while sufficiently satisfying the above quality, but there are the following problems.

Even if a solidifying agent is added to solidify the silt / clay component 3, since the silt / clay component 3 is fine particles, sufficient adhesion with the solidifying agent cannot be secured and a reaction is sufficiently caused. Is difficult. The silt / clay component 3 takes in Ca ²⁺ ions necessary for solidification, and the hydration reaction becomes difficult to occur. If the silt / clay component 3 is of a type that forms a layered crystal, peeling breakage easily occurs, and it becomes difficult to secure the strength.

[0007]

[Means for Solving the Problems] A method for producing a recycled aggregate according to the present invention for solving the above-mentioned problems is a method in which a hydration reagent is added to a silt / clay component separated from construction mud and mixed. The recycled aggregate is characterized by being obtained by heating and pressurizing at a pressure of 100 kg / cm ² or more to cause a dehydration effect and consolidating and then crushing.

[0008] In the production method of the aforementioned recycled aggregate, the
Hydration reaction agent is cement, or cement and ground improvement
It is characterized by being an agent . Method for producing the above-mentioned recycled aggregate
In the case where the hydration reagent is cement,
The silt / clay component is added prior to adding the cement.
By adding lime to and mixing the silt and clay
It is characterized in that the components are heated to generate heat. Above re
In the method of manufacturing raw aggregate, gravel collected from construction mud
Mixing a part of the sand component with the silt / clay component
Characterize.

Further, the apparatus for producing recycled aggregate according to the present invention is obtained by the addition mixing means for adding the hydration reaction agent to the silt / clay component separated from the construction mud and mixing the mixture. the mixture was heated and 100 kg / cm ² or more
A heating means and a pressurizing means for producing a dehydrated action by pressurizing with a pressure of 1 to obtain a solidified body by consolidation and solidification, and a crushing means for crushing the solidified body to obtain recycled aggregate. And

[0010] In the production apparatus of the aforementioned recycled aggregate, the
Hydration reaction agent is cement, or cement and ground improvement
It is characterized by being an agent . Equipment for manufacturing recycled aggregate described above
In, the hydration reagent is cement, and the heating
Means for adding the cement prior to adding the cement.
・ By adding lime to the clay component and mixing,
The fact that the clay and clay ingredients are heated to generate heat
Characterize. In the above-mentioned recycled aggregate manufacturing equipment, construction
Part of the gravel and sand components collected from the mud is the silt and clay
It is equipped with a gravel / sand component supply means
Characterize.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of a method for manufacturing a recycled aggregate and an apparatus therefor according to the present invention will be described with reference to FIG. Note that FIG. 1 is a flow chart showing a schematic configuration of the device.

As shown in FIG. 1, the construction mud 1 is put into the gravel / sand sorting equipment 10 and has a large particle size gravel / sand component 2.
(D ≧ 74 μm) is sent to the screen 12 to remove water, and then temporarily stored in the hopper 13 and reused as a backfill material, while the screen 12 collects gravel / sand components 2
The remaining components removed from the coagulant tank 21 are sent from the flocculant tank 21 via the pump 22 to the mechanical dehydrator 23 together with the inorganic or polymer flocculant, and the silt / clay component 3 (d <74 μm) is collected. The water separated by the screen 12 is stored in the water tank 14 and supplied again to the cyclone 11 via the pump 15, and the water separated by the dehydrator 23 is supplied again to the cyclone 11. There is.

In this embodiment as described above, the cyclone 11, the screen 12, the hopper 13, the water tank 14, the pump 15 and the like constitute the gravel and sand collecting equipment 10, and the flocculant tank 21, the pump 22, and the dehydrator 23. The solid-liquid separation equipment 20 is constituted by the above, and the gravel / sand separation equipment 10, the solid-liquid separation equipment 20, etc. constitute the silt / clay component separation means.

Subsequently, as shown in FIG. 1, the silt / clay component 3 is added with cement 101 (which can secure long-term stability) such as early-strength Portland cement, which is a hydration reagent, from the addition device 31. Then, the mixture is fed to the mixer 32, mixed and stirred to adjust the particle size, and then the mixture is fed to the heating and pressurizing device 33 to be heat-treated and pressure-treated to be a solidified body 4 by a consolidation and solidification reaction. .

In this embodiment as described above, the addition device 3 is used.
1, the mixer 32 and the like constitute the addition and mixing means, the heating and pressurizing device 33 and the like constitute the heating means and the pressure means, and the addition and mixing means, the heating means and the pressure means constitute the solidification treatment equipment 30. ing.

Next, the solidified body 4 is fed to a crushed stone facility 40 which is a crushed stone means, crushed, and then classified and post-treated to obtain coarse aggregate (5 mm mixed in concrete.
It is equivalent to the above crushed stone, and about 45
% Is mixed. ) Etc. can be obtained as recycled aggregate 5.

That is, cement 1 in silt / clay component 3
Addition of 01 causes water and cement 101 to undergo an exothermic hydration reaction to reduce the water content in the silt / clay component 3 and harden it while condensing, and then heat and pressurize the mixture to further dehydrate it. At the same time, the gap after dehydration was reduced so as to be consolidated and solidified.

Here, in the above heat treatment, not only is the exotherm forcedly generated, but also the hydration reaction between cement 101 and water, cement 101 and silt / clay component 3
In the above pressure treatment, in addition to physical consolidation and solidification, the reaction area is increased by closely adhering between the fine particles to promote the hydration reaction, the binding reaction, etc. It has the effect of causing it.

Therefore, the recycled aggregate 5 which can sufficiently satisfy the quality as the aggregate such as the strength and the water absorption rate of the recycled coarse aggregate and the recycled fine aggregate defined by Japanese Industrial Standards is used. It can be manufactured at a lower cost than the purchase cost of aggregate.

Therefore, it is not necessary to dispose of the construction mud generated by the construction of an underground structure such as a tunnel as an industrial waste for a fee, so that the construction cost of the underground structure can be reduced. Not only can problems such as shortage of waste soil disposal sites and transportation costs be solved, but natural aggregate resources can be effectively used.

A second embodiment of the method and apparatus for producing recycled aggregate according to the present invention will be described with reference to FIG. Note that FIG. 2 is a flow chart showing a schematic configuration of only the solidification treatment equipment part of the apparatus. However, the same parts as those in the first embodiment described above are denoted by the same reference numerals as those used in the description of the first embodiment, and the description thereof will be omitted.

As shown in FIG. 2, the silt / clay component 3 separated from the construction mud 1 is mixed with the cement 101 and the ground improvement agent 102, which is another hydration reaction agent, from the addition device 31 and mixed. After being fed to 32, mixed and stirred and adjusted in particle size, and once stored in a hopper 34, this mixture is fed to a heating / pressurizing device 33 to be subjected to heat treatment and pressure treatment, whereby a solidified body is formed by a consolidation and solidification reaction. It becomes 4.

That is, by further adding the ground improvement agent 102 to the silt / clay component 3, a large amount of water in the silt / clay component 3 is taken into the silt / clay component 3 so that the needle-like structure is reticulated. A hydrate (ettringite) that grows was produced, and when the hydrate was sufficiently grown, it was heated and pressed to consolidate.

In this embodiment, the addition device 3
1, the mixer 32, the hopper 34, and the like constitute an adding and mixing means. The hopper 34 is a stockyard for sufficiently growing the hydrate, and is for controlling the stock time according to the type of the silt / clay component 3 and the use of the solidified body 4. .

For this reason, in the present embodiment, even if the silt / clay component 3 is of a type that forms a layered structure crystal, it is possible to prevent peeling and fracture and secure sufficient strength. it can.

Therefore, the same effects as in the case of the first embodiment described above can be obtained, and even if the silt / clay component 3 is of a type forming a layered structure crystal, the above-mentioned effects can be obtained. It is possible to obtain the recycled aggregate 5 having higher strength than in the case of the first embodiment.

A third embodiment of the method and apparatus for producing recycled aggregate according to the present invention will be described with reference to FIG. Note that FIG. 3 is a flow chart showing a schematic configuration of only the solidification treatment equipment part of the apparatus. However, the same parts as those in the first and second embodiments described above are denoted by the same reference numerals as those used in the description of the first and second embodiments, and the description thereof is omitted. To do.

As shown in FIG. 3, the silt / clay component 3 separated from the construction mud 1 is supplied from the addition device 35 to the lime 10
3 was added and fed to the mixer 36, mixed and stirred to adjust the particle size, and once stored in the hopper 34, cement 101 was added from the addition device 31 to the mixer 32 and fed to the mixer 32, mixed and stirred. After the particle size is adjusted, this mixture is fed to a pressurizing device 37 which is a pressurizing means and subjected to a pressurizing treatment, and becomes a solidified body 4 by a consolidation and solidification reaction.

That is, cement 1 in silt / clay component 3
Lime 1 which is also a hydration reagent prior to the addition of 01
By adding 03 and making the lime hydration reaction generate heat,
Even the pressurizing device 37, which has only the pressurizing mechanism and omits the heating mechanism, can perform a sufficient consolidation reaction.

In this embodiment as described above, the hopper 3
4, the addition device 35, the mixer 36, the lime 103, and the like constitute a heating means. The hopper 34 is a stockyard for maximally promoting the exothermic reaction of the lime 103, and is for controlling the time taken for the temperature to rise. Depending on the amount of lime 103 added, for example, The hopper 34 is omitted, and it is controlled by the mixing and stirring time of the mixer 36.
It is also possible to omit 5 and the mixer 36, add the cement 101 and the lime 103 from the adding device 31 and mix and stir them simultaneously in the mixer 32 to control the above time.

Therefore, in the present embodiment, it is of course possible to obtain the same effects as in the case of the first embodiment described above, and more than in the case of the first embodiment described above. The cost of initials and processing can be reduced.

A fourth embodiment of the method and apparatus for producing recycled aggregate according to the present invention will be described with reference to FIG. Note that FIG. 4 is a flow chart showing a schematic configuration of the device. However, for the same parts as those in the first to third embodiments described above, the same reference numerals as those used in the description of the first to third embodiments described above are used, and the description thereof is omitted. To do.

As shown in FIG. 4, in the silt / clay component 3 collected from the construction mud 1, the cement 101 is added from the adding device 31, and then the gravel / collection collected from the construction mud 1 is added.
Supply device 3 in which a part of sand component 2 is gravel / sand component supply means
After being charged from 8, the mixture is supplied to the mixer 32, mixed and stirred, and the particle size is adjusted, and this mixture is sent to the heating and pressurizing device 33 to be heat-treated and pressure-treated to be a solidified body 4 by a consolidation and solidification reaction. .

That is, a part of the collected gravel / sand component 2 is mixed with the silt / clay component 3 to obtain the cement 10
Even if the addition amount of 1 is reduced, a high-strength solidified body 4 can be obtained.

Therefore, in the present embodiment, it is of course possible to obtain the same effect as in the case of the first embodiment described above, and for example, in the case of construction mud such as sand and gravel ground and sand ground. If it is applied to the case where the gravel / sand component 2 contained in 1 is extremely large, the manufacturing cost can be reduced as compared with the case of the first embodiment described above.

In each of the above-mentioned embodiments,
As the pressure applied by the pressurizing means and the heating temperature by the heating means are higher, the solidified body 4 with higher strength can be manufactured, and in particular,
When the pressure applied by the pressurizing means is 100 kg / cm ² or more, the above-described effect due to the pressurization is sufficiently exhibited, and more preferable results can be obtained.

[0037]

According to the method of manufacturing recycled aggregate according to the present invention,
After adding the hydration reagent to the silt / clay component collected from the construction mud and mixing, pressurizing it to cause dehydration and consolidation and then crushing to obtain regenerated aggregate. After the hydration exothermic reaction between the wa-reactant and water causes the moisture in the silt / clay component to decrease and hardens while condensing, pressurization causes a further dehydration action and the gap after dehydration decreases. Recycled aggregate that can sufficiently satisfy the quality of aggregate such as strength and water absorption as recycled coarse aggregate and recycled fine aggregate specified by industrial standards is cheaper than the purchase cost of natural aggregate It can be manufactured. As a result, it is not necessary to dispose of the construction mud generated by the construction of underground structures such as tunnels as industrial waste for a fee, so that it is possible to reduce the construction cost of the underground structures and to remove the remaining soil. Not only can problems such as a shortage of disposal sites and transportation costs be resolved, but natural aggregate resources can be effectively used.

Further, if the above-mentioned pressurization is carried out at a pressure of 100 kg / cm ² or more, the action of physically consolidating and consolidating and the reaction area is increased by bringing the fine particles into close contact with each other to cause a hydration reaction or a binding reaction. Since the promoting action can be sufficiently brought out, more preferable results can be obtained.

In the apparatus for producing recycled aggregate according to the present invention, the addition mixing means for adding the hydration reaction agent to the silt / clay component separated from the construction mud and mixing the mixture and the mixture obtained by the addition mixing means are used. Since it is provided with a pressurizing means for applying a dehydration action by pressurizing and for solidifying and solidifying to obtain a solidified body, and a crushed stone means for crushing the solidified body to obtain a recycled aggregate, a silt with an adding and mixing means. By adding the hydration reaction agent to the clay component and mixing, the hydration reaction agent and water undergo an hydration exothermic reaction to reduce the water content in the silt / clay component and cure while hardening. By pressurizing the mixture with a pressurizing means, the dehydration action further occurs and the gap after dehydration decreases, so the strength and water absorption rate of recycled coarse aggregate and recycled fine aggregate specified in Japanese Industrial Standards etc. Quality as aggregate The recycled aggregate that can be met can be produced cheaper than the cost of purchasing natural bone material.
As a result, it is not necessary to dispose of the construction mud generated by the construction of underground structures such as tunnels as industrial waste for a fee, so that it is possible to reduce the construction cost of the underground structures and to remove the remaining soil. Not only can problems such as a shortage of disposal sites and transportation costs be resolved, but natural aggregate resources can be effectively used.

Further, the pressurizing means is 100 kg / cm ²
If it is possible to pressurize with the above pressure, it is possible to sufficiently bring out the action of physically consolidating and solidifying, and the action of increasing the reaction area by adhering the fine particles to each other to promote the hydration reaction, the binding reaction, etc. More favorable results can be obtained.

[Brief description of drawings]

FIG. 1 is a flow diagram showing a schematic configuration of a first embodiment of an apparatus for manufacturing recycled aggregate according to the present invention.

FIG. 2 is a flow chart showing a schematic configuration of only a solidification treatment facility portion of a second embodiment of the apparatus for producing recycled aggregate according to the present invention.

FIG. 3 is a flow chart showing a schematic configuration of only a solidification treatment equipment portion of a third embodiment of the apparatus for producing recycled aggregate according to the present invention.

FIG. 4 is a flow chart showing a schematic configuration of a fourth embodiment of the apparatus for manufacturing recycled aggregate according to the present invention.

FIG. 5 is a conventional processing flow diagram of construction mud.

[Explanation of symbols]

1 construction mud 2 gravel and sand components 3 silt and clay ingredients 4 Solidified 5 recycled aggregate 10 Gravel and sand sorting equipment 11 cyclones 12 screens 13 hoppers 14 aquarium 15 pumps 20 Solid-liquid separation equipment 21 Flocculant tank 22 pumps 23 Dehydrator 30 Solidification treatment equipment 31 Addition device 32 mixer 33 Heating and pressurizing device 34 hopper 35 Addition device 36 mixer 37 Pressurizing device 38 feeder 40 stone crushing equipment 101 cement 102 Ground improvement agent 103 lime

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomokatsu Yamamoto 2-1-1, Niihama, Arai-cho, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (56) Reference JP-A-8-229593 (JP, A) Special Kaihei 7-68237 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C04B 18/12 C04B 18/16 C04B 18/30

Claims (8)

(57) [Claims] 1. When a hydration reaction agent is added to and mixed with the silt / clay component collected from construction mud, heating and 100 k
A method for producing a regenerated aggregate, which comprises pressurizing at a pressure of g / cm ² or more to cause a dehydration action and consolidation and solidification, and then crushing to obtain a regenerated aggregate. 2. The hydration reagent is cement or cement.
Ment and ground improvement agent.
A method for producing the recycled aggregate according to [4]. 3. When the hydration reagent is cement
Before adding the cement,
By adding lime to the soil component and mixing, the silt
.Claims characterized by heating the clay component to generate heat
Item 2. A method for producing a recycled aggregate according to Item 1. 4. A part of gravel and sand components collected from construction mud
Is mixed with the silt / clay component.
The method for producing a recycled aggregate according to claim 1. 5. Silt and clay components collected from construction mud
And a mixing means for adding and mixing a hydration reactant to The mixture obtained by the adding and mixing means is heated and heated to 100 k
g / cm ² Pressurize with the above pressure to cause dehydration
Heating means and pressurizing hand to obtain a solidified body by consolidating and solidifying with
Dan, Crushing means for crushing the solidified body to obtain recycled aggregate Equipped with
An apparatus for manufacturing recycled aggregate, which is characterized in that 6. The hydration reagent is cement or cement.
Ment and ground improvement agent.
An apparatus for producing recycled aggregate according to item 1. 7. The hydration reagent is cement, and
A heating means is used to add the cement prior to adding the cement.
By adding lime to the clay and clay components and mixing
The silt / clay component is heated to generate heat.
The apparatus for manufacturing recycled aggregate according to claim 5, wherein 8. Part of gravel and sand components collected from construction mud
Means for feeding gravel / sand components to the above silt / clay component
The regenerated bone according to claim 5, further comprising:
Material manufacturing equipment.