JPH0873852A - Construction method for earth building materials and permeable ground - Google Patents

Abstract

(57) [Summary] [Structure] A material for the formation of a permeable ground and a base material for lawns consisting of recycled soil treated with lime after granulation by adding a water-soluble polymer to water-containing soil such as construction soil and A method of constructing a permeable ground using these materials. [Effect] Since the material made of the reclaimed soil of the present invention has excellent water permeability, it can be used not only for backfilling of buried pipes for road construction, but also for construction of golf courses, construction of grounds for schoolyards, etc. Is widely used for roadbed parts of permeable pavement, shortening the construction time and suppressing the amount of excavated soil left behind, which has a great economic effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the use of construction soil, etc., and more specifically, an earth building material produced by solidifying the construction soil generated during construction and civil engineering, etc. It is related to the reuse of water for the construction of permeable ground.

[0002]

2. Description of the Related Art Conventionally, most of the soil generated by construction cannot be reused and has been disposed of in landfills or taken out to other places, but its environmental impact has become a problem. Under such circumstances, although the amount of treatment is small in recent years, the soil generated from construction is being recycled in plants by lime treatment. This is because in the case of road construction, sand was used to backfill the excavated site, but for that reason, mountain sand had to be brought in from other places, which also caused environmental damage. As it happens, reclaimed soil treated with lime at the plant is used instead of backfilled sand.

However, since such a plant is intended only for high-quality construction soil having a low water content, the soil which has been dried in the sun on a vast site to have a low water content is improved with quicklime to regenerate the regenerated soil. Therefore, there were restrictions on the actual application in the field. Further, the improved soil produced by the quick lime treatment produced in such a plant becomes soft when exposed to rain and cannot be used for other purposes. The inventor
In order to solve such a problem, the soil generated by construction is not dried in the sun as it is, but is granulated in a plant by using a specific modifier to obtain improved soil having sand-like fluidity. (Japanese Patent Laid-Open No. 4-171039).

[0004]

In the construction work of high-class golf courses that are currently being carried out in various places, drainage pipes are buried to obtain water permeability, crushed stones are laid, and a large amount of mountain sand is placed on top of them. After being created by using it, the grass is usually planted after covering with black soil to a thickness of 5 to 10 cm. However,
Since there is a problem such as depletion of mountain sand and disposal of soil generated during construction in this construction work, most of the golf course construction sites use generated soil instead of sand, so water permeability is high. There was a problem with the growth of the grass. In addition, generally the ground, especially the schoolyard, has poor drainage, so sprinkle sand on the surface to deal with it each time, but in order to improve drainage, at present the soil is dug up regularly and the soil on the surface layer is replaced, There is a problem that the construction period requires 2-3 months.

Further, in recent years, for the purpose of improving drainage on the road surface during rain, improving the ease of walking on sidewalks, and protecting and nurturing roadside trees, water-permeable pavement paving with asphalt having high water permeability has been actively carried out. ing. However, in this case, although the water permeability immediately after construction is good, there is a problem that the water permeability gradually decreases. The present invention provides a method of using the improved soil obtained from construction-generated soil by making full use of its properties such as water permeability and appropriate hardness, and in particular, a method used for forming a water-permeable ground.

[0006]

Means for Solving the Problems In order to promote the reuse of residual soil such as soil generated from construction, the present inventor has made use of the physical properties of the regenerated soil produced by the method proposed above, that is, the utilization of water permeability. As a result of intensive studies, the present invention has been reached. That is, the gist of the present invention is to add a water-soluble polymer to a water-containing soil and granulate it, and then use a permeable ground forming material consisting of reclaimed soil treated with lime, a material for a turf ground, and these materials. It exists in the method of creating a permeable ground.

Hereinafter, the present invention will be described in detail. The material for forming a water-permeable ground and the material for a base of a lawn of the present invention are formed by adding a water-soluble polymer to a water-containing soil such as construction soil and granulating the regenerated soil further treated with lime or the like. It is what is done. As a method for producing this reclaimed soil, Japanese Patent Laid-Open No.
Although the method described in −345685 can be used, it is manufactured, for example, as follows. First, the construction soil and the water-soluble polymer are mixed with a mixer to granulate. Next, the generated granules are treated with a solidifying material such as lime. Usually, the solidifying material is added and mixed, and solidified in the granular form to obtain recycled soil. In order to sufficiently exhibit the improved properties of the reclaimed soil, it is usually preferable to use it after curing for 2 to 3 days. The mixer to be used is not particularly limited as long as the mixing efficiency is good, but it is preferable to mix the water-soluble polymer with a twin-screw mixer having mixing and granulating functions for 20 seconds or more. The mixer of the solidifying material such as lime in the latter stage may be of any model, but it is preferable that the solidifying material is uniformly dispersed and adhered to the surface of the particles granulated in the former stage, for example, the same as the former twin-screw mixer. However, it is preferable to use a tumbling mixer utilizing the height difference.

As the water-soluble polymer used for producing the reclaimed soil, any water-soluble polymer having a function of aggregating the water-containing soil can be used. Here, the water-soluble polymer usually means a polymer that dissolves in 1 g or more in at least 100 ml of water, and a polymer having such a function usually has a carboxyl group as a hydrophilic group. Those are preferable. Specifically, gum arabic, karaya gum, tragacanth gum, natural acidic polysaccharides such as alginates, semi-synthetic water-soluble polymer substances such as carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, and neutral such as guar gum and locust bean gum. Examples include modified polysaccharides.

As the synthetic water-soluble polymer, a (meth) acrylamide polymer containing (meth) acrylic acid or its salt, a copolymer of maleic acid or its salt and vinyl acetate, itaconic acid or Examples thereof include a copolymer of the salt and (meth) acrylamide, and a (meth) acrylamide-based polymer containing (meth) acrylic acid or a salt thereof is preferable. As the acrylamide polymer containing (meth) acrylic acid or a salt thereof,
In addition to a copolymer of (meth) acrylic acid or a salt thereof and (meth) acrylamide, a partially hydrolyzed product of (meth) acrylamide may be used, and further, the above monomers are combined and copolymerized. It may be one.

Examples of the salt include alkali metal salts such as sodium and potassium, alkaline earth metal salts such as calcium and magnesium, ammonium salts, amine salts such as alkylamines having 1 to 18 carbon atoms and alkanolamines. , And a mixture of two or more thereof, but an alkali metal salt is preferable. In the case of the synthetic water-soluble polymer as described above, the monomer having a carboxyl group is usually 1 to 8 among all the monomers constituting the polymer.
It is contained in an amount of 0 mol%, preferably 5 to 60 mol%. Also,
The carboxyl group may be present in either free acid or salt form.

The water-soluble polymer may be added in any form as long as the construction soil, which is the raw material, is aggregated. However, since ordinary soil has a high water content, it is added as a powder and the average particle size is 0. .4
It is preferable to use a carboxyl group-containing water-soluble polymer powder having a size of mm or less. When the water content ratio of the treated soil is low, water content may be added to adjust the water content ratio. The amount of the water-soluble polymer added varies depending on the state of the treated soil, but is usually 0.01 to 1% by weight, preferably 0.01 to 0.5% by weight, relative to the treated soil. Further, the mixing residence time of the water-soluble polymer powder and the treated soil is preferably 20 seconds or more.

The solidifying material for lime used for the production of reclaimed soil preferably adheres uniformly to the surface of the soil particles granulated in the preceding step, and therefore, powdered lime having a particle size of 1 mm or less is used. It is desirable to use. In the present invention, it is desirable that the regenerated soil after solidification is retained in the granular form for a long period of time, and lime as the solidifying material contains calcium oxide and calcium hydroxide as the main components. Includes quick lime, slaked lime, hydraulic cement, lime-based improver, cement-based improver and the like. For practical use in the plant, quicklime-based powder that has a fast dehydration and hardening reaction is desirable, but other solidifying materials can be appropriately selected and used depending on the use of the reclaimed soil. The addition amount of the solidifying material such as quick lime is 0.2 to 20% by weight, preferably 0.5 to 1 with respect to the treated soil.
0% by weight. The obtained reclaimed soil is sieved as needed according to the purpose of use, cured for 2 to 3 days, and then used as respective materials.

When actually using the material of the present invention, in addition to the method of manufacturing and using recycled soil in a plant for improving construction soil, a temporary plant is installed at the site of generation to use the soil as recycled soil. You can also do it. In addition, it is also possible to directly improve the generated soil at the generation site to regenerate it, but in that case, for example, spray the water-soluble polymer directly onto the surface of the treated ground such as a land reclamation site, or, while spraying, the cultivator. After thoroughly mixing with a stabilizer, a backhoe or the like to form aggregates, lime or the like is sprayed again and mixed. Mixing of lime etc. may be easier if the agglomeration is good. In order to obtain sufficient strength of the aggregated reclaimed soil, it is better to let it stand for 3 days or more, preferably for 1 to 2 weeks, and then perform roller compaction.

As other additives to the treated soil used in the present invention, not only sand but also super absorbent resin, gypsum, fly ash and the like can be used together to adjust the soil improving effect. . The granular reclaimed soil thus obtained is used not only for backfilling existing buried pipes, but also for constructing golf courses that utilize water permeability and for constructing grounds. It is also an excellent material. And
Since the granular reclaimed soil of the present invention has fluidity, it has better workability than mountain sand for backfilling pipes on roads, and has excellent physical properties after construction, and its excellent water permeability makes pipes complicated. It is also effective for tightening water in places where many are laid. Water permeability is important for the green ground of the golf course, but the construction is not uniform and there are many places to fill with generated soil, so the water permeability gradually deteriorates and the roots of the lawn occur. Withered. If the material comprising the reclaimed soil of the present invention is used, the aggregate structure is maintained and the water permeability is good for a long period of time, so root rot does not occur and the lawn growth is good and the lawn growth is extremely good. Are better. Furthermore, if the soil generated during the construction work is directly improved in the plant and used as recycled soil, the generated soil can be disposed of, so environmental problems do not occur.

Conventionally, excavated soil must be discharged and fresh soil must be brought in from other places when exchanging soil to improve drainage in the grounds of schools and the like.
It required a construction period of at least 2-3 months. However, according to the present invention, if a simple plant is installed at the corner of the ground and the excavated soil is reclaimed soil at the site, all the carry-out and carry-in of the soil will be eliminated. It is not necessary and advantageous. In addition, the ground after construction has excellent water permeability, so children can play even after rain, and because there are no stones, it is less likely to fall and get injured. 1-3 on the surface of the ground depending on the purpose of use
Antuker (crushed brick) or Arakida sand may be laid to a thickness of cm. Furthermore, in the case of water-permeable pavement using the material of the present invention, if the reclaimed soil is applied to the subgrade and the sand layer portion, the water permeability can be maintained for a long period of time, and planting is also possible. If reclaimed soil is also used for the planting part, the water permeability will not decrease further due to the hydration of plants such as roadside trees.

[0016]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 A planting test was conducted on a golf course land by using recycled soil in a section having a width of 10 m and a length of 20 m. The recycled soil used is
A 30 ton construction waste soil recycling plant per hour, 0.1% by weight of polyacrylamide-acrylic acid copolymer (80:20 mol product) based on the generated soil (water content ratio 98%) mainly consisting of Kanto loam. And a product improved with 3% by weight of quick lime, passed through a 6 mm sieve, and had an average particle size of 1.4 mm. In addition, the one that was aged for 4 days after production was used, and the water content ratio was 41.9% on average.
BR was 18.9%.

Excavation depth, diameter of 10 cm at the bottom of 80 cm
Fill the drainage pipe of No. 1 and put crusher run (C-40) on the pipe.
The soil was spread to 0 cm, and reclaimed soil was spread to 50 cm, and a leveling roller was applied. Further, in order to prevent the soil from drying, black soil was laid for about 10 cm, and turf was planted. 2 months after planting,
After observing for 4 months, it was cut into a size of 30 × 30 cm and dug up to observe the growth of roots. The test results are summarized in Table 1.

Example 2 A crusher run was placed on the tube 5 cm, reclaimed soil 15 cm, and black soil 5
A planting test was carried out in the same manner as in Example 1 except that cm was used. The results are shown in Table-1.

Comparative Example 1 Example 1 was repeated except that the reclaimed soil was normally used mountain sand.
Grass was planted in the same manner as in. The results are shown in Table-1. Comparative Example 2 Grass was planted in the same manner as in Example 1 except that the regenerated soil was dug up to generate soil. Similarly, the results are shown in Table 1.

[0021]

[Table 1]

Example 3 In an open space, a ground construction test was conducted using reclaimed soil in a section having a width of 10 m, a length of 20 m and a depth of 50 cm. The reclaimed soil used was a 30 ton construction waste soil recycling plant per hour, and the generated soil (water content ratio 83
%) Was obtained in the same manner as in Example 1 except that
The one that passed through a 6 mm sieve is used, and the average particle size is 1.8.
mm. In addition, the thing which was aged for 7 days after manufacture was used, the water content ratio was 38.5% on average, and CBR was 24.
It was 6%. For construction, a water-permeable pipe with a diameter of 10 cm was laid, and after crushed stone (crusher run) was put in for about 10 cm,
The reclaimed soil was put in a thickness of about 50 cm. Next, the roller was compacted, and the reclaimed soil that had passed through a 2 mm sieve was spread to a thickness of 3 to 5 cm, and the roller was compacted further. Compared to the surrounding compartments, the water permeability was excellent even when it rained, it did not become soft, and it was possible to exercise immediately after the rain stopped. In addition, it was confirmed that dust did not stand even when dried.

Comparative Example 3 A ground construction test was conducted in the same manner as in Example 3 except that generated soil was used instead of regenerated soil. As compared with Example 3, the water permeability was poor, and it was impossible to exercise immediately after the rain.

Example 4 The same as Example 1 except that excavated soil having a water content of 86% was used and 6% by weight of cement: quicklime was added at a weight ratio of 1: 1 as an additive. I got recycled soil. The obtained reclaimed soil had an average particle size of 1.6 mm and a CBR of 42.4%. Dig down the sidewalk about 35 cm,
After laying the reclaimed soil to a thickness of 25 cm and crushing it with 10 cm of crusher run (C-40), it was about 30 cm. Next, a water-permeable pavement was applied to a thickness of 4 to 5 cm. The water permeability was very good, and it was confirmed that it penetrates sufficiently even in heavy rain.

Comparative Example 4 A sidewalk portion was dug down by 20 cm, a depth of 20 cm was dug back, and about 3% of quick lime was added to this, and after mixing with stirring, rolling was performed and curing was carried out for 7 days to obtain a roadbed. Next, lay a pile of sand to a thickness of 5 cm, and then add crusher run (C-40) to 10 c.
After being placed m, it was rolled. A water-permeable pavement having a thickness of 5 cm was applied thereon. Permeability is better than general sidewalks,
It was confirmed that when the amount of rainwater increased, the drainage was poor and was inferior to that of Example 4.

[0026]

EFFECTS OF THE INVENTION Conventionally, the use of reclaimed soil produced in a plant by the quick lime treatment method was only part of the backfilling of buried pipes for road construction. Civil engineering materials made of granular reclaimed soil obtained by treating with polymer and lime are used for backfilling conventional buried pipes,
Since it is also suitable for the construction of water-permeable ground, it is excellent as a golf course construction and grass base material. Furthermore, it is also ideal for creating permeable grounds such as schoolyards and roadbeds with permeable pavement. In any case, compared to the conventional construction method, the soil generated at the site is improved to be recycled soil, which can be used instead of sand or sand to reduce the cost, shorten the construction time, and reduce the amount of soil remaining after excavation. Since the amount of generation can be suppressed, the economic effect is great. In this way, by expanding the field of use of soil generated from construction, it is possible to promote the suppression of soil generated from excavation and to promote recycling, which greatly contributes to environmental problems.

Claims (8)

[Claims] 1. A material for forming a water-permeable soil, which comprises reclaimed soil treated with lime after being granulated by adding a water-soluble polymer to hydrous soil. 2. A material for a lawn base, which comprises reclaimed soil treated with lime after being granulated by adding a water-soluble polymer to hydrous soil. 3. The material according to claim 1, wherein the water-soluble polymer is a (meth) acrylamide polymer containing (meth) acrylic acid or a salt thereof. 4. The material according to claim 3, wherein the water-soluble polymer is a polymer containing a monomer having a carboxyl group as a hydrophilic group in an amount of 5 to 60 mol% based on all monomers. 5. The weight ratio of water-soluble polymer to lime is 1: 1 to 1.
The material according to claim 1 or 2, which has a ratio of 1: 500. 6. A method for constructing a permeable ground using reclaimed soil treated with lime after granulating by adding a water-soluble polymer to hydrous soil. 7. The material according to claim 1, wherein the water-containing soil is construction soil generated in civil engineering and construction work. 8. The method according to claim 6, wherein the water-containing soil is construction soil generated in civil engineering and construction work.