JP7120847B2 - Soil solidification treatment method - Google Patents
Soil solidification treatment method Download PDFInfo
- Publication number
- JP7120847B2 JP7120847B2 JP2018155371A JP2018155371A JP7120847B2 JP 7120847 B2 JP7120847 B2 JP 7120847B2 JP 2018155371 A JP2018155371 A JP 2018155371A JP 2018155371 A JP2018155371 A JP 2018155371A JP 7120847 B2 JP7120847 B2 JP 7120847B2
- Authority
- JP
- Japan
- Prior art keywords
- soil
- mass
- light
- magnesium oxide
- magnesium carbonate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Soil Conditioners And Soil-Stabilizing Materials (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Description
本発明は、固化材、及び、土壌の固化処理方法に関する。 TECHNICAL FIELD The present invention relates to a solidification material and a soil solidification method.
従来、土壌の改良方法として、土壌にセメント等の固化材を添加し、混合することで、土壌の強度(例えば、一軸圧縮強さ)を発現させる方法が知られている。
例えば、特許文献1には、水硬性粉体からなる固化材であって、温度が90℃であり、かつ、無風状態の雰囲気下で5分間加熱した場合における質量の減少量が、上記水硬性粉体100質量部に対して、0.28~0.76質量部である量の水分を含むことを特徴とする固化材が記載されている。
また、特許文献2には、リートベルト法で測定したC3S量が50質量%以上であるセメントと、石膏を含むセメント系固化材が記載されている。
Conventionally, as a method for improving soil, a method is known in which a solidification material such as cement is added to the soil and mixed to express the strength of the soil (for example, unconfined compressive strength).
For example, in Patent Document 1, a solidifying material made of hydraulic powder is heated at a temperature of 90 ° C. for 5 minutes in a windless atmosphere. A solidifying material characterized by containing 0.28 to 0.76 parts by mass of water with respect to 100 parts by mass of powder is described.
Further, Patent Document 2 describes a cement-based solidifying material containing cement having a C 3 S content of 50% by mass or more as measured by the Rietveld method and gypsum.
本発明の目的は、土壌に対して優れた強度発現性(例えば、固化材を添加し混合した時から7~28日後の土壌の一軸圧縮強さが大きいこと)を与えることのできる固化材、及び、該固化材を用いた土壌の固化処理方法を提供することである。 An object of the present invention is to provide a solidifying material that can impart excellent strength development to soil (for example, a large unconfined compressive strength of soil 7 to 28 days after adding and mixing the solidifying material), Another object of the present invention is to provide a soil solidification method using the solidification material.
本発明者は、上記課題を解決するために鋭意検討した結果、酸化マグネシウム含有物質と特定の化学式を有する塩基性炭酸マグネシウムを含む固化材によれば、上記目的を達成できることを見出し、本発明を完成した。
すなわち、本発明は、以下の[1]~[5]を提供するものである。
[1] 酸化マグネシウム含有物質と下記化学式で表される塩基性炭酸マグネシウムを含むことを特徴とする固化材。
mMgCO3・Mg(OH)2・nH2O
(上記化学式中、mは3~5の整数であり、nは3~7の整数である。)
[2] 酸化マグネシウム含有物質が、軽焼マグネシア、軽焼マグネシアの部分水和物、軽焼ドロマイト、及び、軽焼ドロマイトの部分水和物の中から選ばれる少なくとも1種である前記[1]に記載の固化材。
[3] 上記酸化マグネシウム含有物質と上記塩基性炭酸マグネシウムの合計量中の、上記塩基性炭酸マグネシウムの量の割合が、0.4~18.0質量%である前記[1]または[2]に記載の固化材。
[4] 前記[1]~[3]のいずれかに記載の固化材を、土壌に添加し、混合することを特徴とする土壌の固化処理方法。
[5] 上記土壌が、火山灰質粘性土である前記[4]に記載の土壌の固化処理方法。
As a result of intensive studies in order to solve the above problems, the present inventors found that the above objects can be achieved by a solidifying material containing a magnesium oxide-containing substance and basic magnesium carbonate having a specific chemical formula, and have completed the present invention. completed.
That is, the present invention provides the following [1] to [5].
[1] A solidifying material comprising a magnesium oxide-containing substance and basic magnesium carbonate represented by the following chemical formula.
mMgCO3.Mg ( OH) 2.nH2O
(In the above chemical formula, m is an integer of 3 to 5, and n is an integer of 3 to 7.)
[2] The above [1], wherein the magnesium oxide-containing substance is at least one selected from light-burnt magnesia, light-burnt magnesia partial hydrate, light-burnt dolomite, and light-burnt dolomite partial hydrate. The solidifying material described in .
[3] The above [1] or [2], wherein the proportion of the amount of the basic magnesium carbonate in the total amount of the magnesium oxide-containing substance and the basic magnesium carbonate is 0.4 to 18.0% by mass. The solidifying material described in .
[4] A method for solidifying soil, which comprises adding the solidifying material according to any one of [1] to [3] to soil and mixing.
[5] The soil solidification method according to [4], wherein the soil is volcanic ash clay.
本発明の固化材、及び、土壌の固化処理方法によれば、土壌に対して優れた強度発現性(例えば、固化材を添加し混合した時から7~28日後の土壌の一軸圧縮強さが大きいこと)を与えることができる。 According to the solidification material and the soil solidification treatment method of the present invention, excellent strength development of the soil (for example, the uniaxial compression strength of the soil 7 to 28 days after adding and mixing the solidification material is You can give a big thing).
本発明の固化材は、酸化マグネシウム含有物質と下記化学式で表される塩基性炭酸マグネシウムを含むものである。
mMgCO3・Mg(OH)2・nH2O
(上記化学式中、mは3~5の整数であり、nは3~7の整数である。)
酸化マグネシウム含有物質の例としては、軽焼マグネシア(MgO)、軽焼マグネシアの部分水和物、軽焼ドロマイト(CaO・MgO)、及び、軽焼ドロマイトの部分水和物の中から選ばれる少なくとも1種が挙げられる。中でも、不純物の含有量が少なく、かつ、入手の容易性の観点から、軽焼マグネシアが好ましい。
軽焼マグネシアの例としては、炭酸マグネシウムと水酸化マグネシウムのいずれか一方または両方を含む固形原料を、好ましくは600~1,300℃の温度で焼成することによって得られるものが挙げられる。
上記固形原料の例としては、マグネサイト、ドロマイト、ブルーサイト、及び、海水中のマグネシウム成分を消石灰等のアルカリで沈澱させて得た水酸化マグネシウム等が挙げられる。これらは、塊状物でもよいし、粉粒状物でもよい。
The solidifying material of the present invention contains a magnesium oxide-containing substance and basic magnesium carbonate represented by the following chemical formula.
mMgCO3.Mg ( OH) 2.nH2O
(In the above chemical formula, m is an integer of 3 to 5, and n is an integer of 3 to 7.)
Examples of the magnesium oxide-containing substance include at least light-burnt magnesia (MgO), light-burnt magnesia partial hydrate, light-burnt dolomite (CaO/MgO), and light-burnt dolomite partial hydrate. 1 type is mentioned. Among them, light-burnt magnesia is preferable from the viewpoint of low impurity content and easy availability.
Examples of light-burnt magnesia include those obtained by burning a solid raw material containing either one or both of magnesium carbonate and magnesium hydroxide, preferably at a temperature of 600 to 1,300°C.
Examples of the solid raw material include magnesite, dolomite, brucite, and magnesium hydroxide obtained by precipitating a magnesium component in seawater with an alkali such as slaked lime. These may be lumps or powders and granules.
軽焼ドロマイトの例としては、ドロマイトを、好ましくは850~1,500℃の温度で焼成することによって得られるものが挙げられる。
軽焼マグネシアまたは軽焼ドロマイトの部分水和物は、軽焼マグネシアまたは軽焼ドロマイトを粉砕した後、当該粉砕物に水を添加して撹拌し混合するか、または、当該粉砕物を相対湿度80%以上の雰囲気下に1週間以上保持して、軽焼マグネシアまたは軽焼ドロマイトを部分的に水和させることによって得ることができる。
Examples of light-burnt dolomite include those obtained by calcining dolomite, preferably at a temperature of 850-1,500°C.
The partial hydrate of light-burnt magnesia or light-burnt dolomite is obtained by pulverizing light-burnt magnesia or light-burnt dolomite and then adding water to the pulverized material and stirring to mix it, or adding the pulverized material to a relative humidity of 80. It can be obtained by partially hydrating light-burnt magnesia or light-burnt dolomite by holding it in an atmosphere of 10% or more for one week or more.
酸化マグネシウム含有物質のブレーン比表面積は、発塵の抑制、および、スラリーで添加する場合の取り扱いの容易性の観点から、好ましくは1,500~20,000cm2/g、より好ましくは2,000~10,000cm2/g、さらに好ましくは2,300~7,000cm2/g、特に好ましくは2,500 ~4,000cm2/gである。
酸化マグネシウム含有物質中の酸化マグネシウムの含有率は、固化処理後の土壌の強度をより大きくする観点から、好ましくは65質量%以上、より好ましくは75質量%以上、さらに好ましくは80質量%以上、特に好ましくは85質量%以上である。
The Blaine specific surface area of the magnesium oxide-containing substance is preferably 1,500 to 20,000 cm 2 /g, more preferably 2,000, from the viewpoints of dust suppression and ease of handling when added in the form of slurry. 10,000 cm 2 /g, more preferably 2,300 to 7,000 cm 2 /g, particularly preferably 2,500 to 4,000 cm 2 /g.
The content of magnesium oxide in the magnesium oxide-containing substance is preferably 65% by mass or more, more preferably 75% by mass or more, and still more preferably 80% by mass or more, from the viewpoint of increasing the strength of the soil after solidification treatment. Particularly preferably, it is 85% by mass or more.
酸化マグネシウム含有物質と塩基性炭酸マグネシウムの合計量中の、酸化マグネシウム含有物質の割合は、固化処理の対象となる土壌の性状によっても異なるが、好ましくは80.0~99.6質量%、より好ましくは82.0~99.0質量%、さらに好ましくは84.0~98.0質量%、特に好ましくは88.0~93.0質量%である。該含有率が80.0質量%以上であれば、固化処理後の土壌の強度(例えば、一軸圧縮強さ)をより大きくすることができる。該含有率が99.6質量%以下であれば、塩基性炭酸マグネシウムの量を十分に確保できるので、固化処理後の土壌の強度をより大きくすることができる。 The ratio of the magnesium oxide-containing substance in the total amount of the magnesium oxide-containing substance and basic magnesium carbonate varies depending on the properties of the soil to be solidified, but is preferably 80.0 to 99.6% by mass, more It is preferably 82.0 to 99.0% by mass, more preferably 84.0 to 98.0% by mass, and particularly preferably 88.0 to 93.0% by mass. When the content is 80.0% by mass or more, the strength (for example, unconfined compressive strength) of soil after solidification treatment can be further increased. If the content is 99.6% by mass or less, a sufficient amount of basic magnesium carbonate can be secured, so that the strength of the soil after solidification treatment can be increased.
塩基性炭酸マグネシウムは、以下の化学式で表されるものである。
mMgCO3・Mg(OH)2・nH2O
上記化学式中、mは、入手の容易性や、固化処理後の土壌の強度をより大きくする観点から、3~5の整数、好ましくは4である。また、nは、入手の容易性や、固化処理後の土壌の強度をより大きくする観点から、3~7の整数、好ましくは3~5の整数、より好ましくは4である。
塩基性炭酸マグネシウムは、通常、mとnが同じもの(例えば、mとnが共に4であるもの)であるが、mとnが異なるもの(例えば、mが4であり、nが3であるもの)でもよい。
また、塩基性炭酸マグネシウムは、上記化学式を有するものを2種以上含んでいてもよい。例えば、mとnが共に4であるものと、mとnが共に3であるものを含んでいてもよい。
塩基性炭酸マグネシウムのBET比表面積は、好ましくは10~60m2/g、より好ましくは20~50m2/g、特に好ましくは30~45m2/gである。該BET比表面積が10m2/g以上であれば、固化処理後の土壌の強度をより大きくすることができる。該BET比表面積が60m2/gを超えると、粉砕にかかる労力やコストが過大となる。
塩基性炭酸マグネシウムの見掛け比重は、好ましくは0.05~1.00g/cm3、より好ましくは0.10~0.80g/cm3、特に好ましくは0.20~0.40g/cm3である。該見掛け比重が0.05g/cm3以上であれば、固化処理後の土壌の強度をより大きくすることができる。該見掛け比重が1.00g/cm3を超えるものは入手が困難である。
Basic magnesium carbonate is represented by the following chemical formula.
mMgCO3.Mg ( OH) 2.nH2O
In the above chemical formula, m is an integer of 3 to 5, preferably 4, from the viewpoint of availability and increasing the strength of the soil after solidification treatment. Also, n is an integer of 3 to 7, preferably an integer of 3 to 5, more preferably 4, from the viewpoint of availability and increasing the strength of the soil after solidification treatment.
Basic magnesium carbonate usually has the same m and n (for example, m and n are both 4), but has different m and n (for example, m is 4 and n is 3). something) is fine.
Also, the basic magnesium carbonate may contain two or more of those having the above chemical formula. For example, a case where both m and n are 4 and a case where both m and n are 3 may be included.
The BET specific surface area of basic magnesium carbonate is preferably 10 to 60 m 2 /g, more preferably 20 to 50 m 2 /g, particularly preferably 30 to 45 m 2 /g. If the BET specific surface area is 10 m 2 /g or more, the strength of the soil after solidification treatment can be increased. When the BET specific surface area exceeds 60 m 2 /g, the labor and cost required for pulverization become excessive.
The apparent specific gravity of basic magnesium carbonate is preferably 0.05 to 1.00 g/cm 3 , more preferably 0.10 to 0.80 g/cm 3 , and particularly preferably 0.20 to 0.40 g/cm 3 . be. If the apparent specific gravity is 0.05 g/cm 3 or more, the strength of the soil after solidification treatment can be increased. Those having an apparent specific gravity exceeding 1.00 g/cm 3 are difficult to obtain.
酸化マグネシウム含有物質と塩基性炭酸マグネシウムの合計量中の、塩基性炭酸マグネシウムの量の割合は、固化処理の対象となる土壌の性状によっても異なるが、好ましくは0.4~20.0質量%、より好ましくは1.0~18.0質量%、さらに好ましくは2.0~16.0質量%、特に好ましくは7.0~12.0質量%である。該含有率が0.4質量%以上であれば、固化処理後の土壌の強度をより大きくすることができる。該含有率が20.0質量%を超えると、酸化マグネシウム含有物質の量が小さくなるため、固化処理後の土壌の強度が小さくなる場合がある。また、該含有率が20.0質量%以下であれば、原料にかかるコストをより低減することができる。 The ratio of the amount of basic magnesium carbonate in the total amount of the magnesium oxide-containing substance and basic magnesium carbonate varies depending on the properties of the soil to be solidified, but is preferably 0.4 to 20.0% by mass. , more preferably 1.0 to 18.0% by mass, still more preferably 2.0 to 16.0% by mass, and particularly preferably 7.0 to 12.0% by mass. If the content is 0.4% by mass or more, the strength of the soil after solidification treatment can be increased. If the content exceeds 20.0% by mass, the amount of the magnesium oxide-containing substance becomes small, and the strength of the soil after solidification treatment may become small. Moreover, if the content is 20.0% by mass or less, the cost of raw materials can be further reduced.
本発明の固化材は、固化処理後の土壌の強度をより大きくする観点から、石膏を含んでいてもよい。
石膏の例としては、フッ酸無水石膏、リサイクル無水石膏、天然無水石膏、リン酸石膏、チタン石膏、精錬石膏、半水石膏、無水石膏、排脱二水石膏、リン酸二水石膏、及び天然二水石膏等が挙げられる。これらは1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
石膏の添加量は、酸化マグネシウム含有物質と塩基性炭酸マグネシウムの合計100質量部に対して、SO3換算で、好ましくは1.0~20.0質量部、より好ましくは2.0~15.0質量部、特に好ましくは3.0~12.0質量部である。該含有率が1.0質量部以上であれば、固化処理後の土壌の強度をより大きくすることができる。該含有率が20.0質量部を超えると、酸化マグネシウム含有物質及び塩基性炭酸マグネシウムの量が小さくなるため、固化処理後の土壌の強度が小さくなる場合がある。
The solidification material of the present invention may contain gypsum from the viewpoint of increasing the strength of the soil after solidification treatment.
Examples of gypsum include gypsum hydrofluoric acid, recycled anhydrite, natural anhydrite, gypsum phosphate, titanium gypsum, refined gypsum, hemihydrate gypsum, anhydrite, dehydrated gypsum, dihydrate gypsum, and natural Dihydrate gypsum and the like can be mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type.
The amount of gypsum to be added is preferably 1.0 to 20.0 parts by mass, more preferably 2.0 to 15.0 parts by mass in terms of SO 3 with respect to a total of 100 parts by mass of the magnesium oxide-containing substance and basic magnesium carbonate. 0 parts by weight, particularly preferably 3.0 to 12.0 parts by weight. If the content is 1.0 parts by mass or more, the strength of the soil after solidification treatment can be increased. If the content exceeds 20.0 parts by mass, the amounts of the magnesium oxide-containing substance and basic magnesium carbonate become small, and the strength of the soil after solidification treatment may become small.
本発明の不溶化材は、必要に応じて、他の成分として、炭酸カルシウム、リン酸カルシウム、ゼオライト、ポリ塩化アルミニウム、水酸化アルミニウム、硫酸アルミニウム、珪石粉末、水酸化マグネシウム、及び、ベントナイトから選ばれる少なくとも1種以上を含んでいてもよい。
他の成分の添加量は、本発明の効果を阻害しない範囲内であればよく、酸化マグネシウム含有物質と塩基性炭酸マグネシウムの合計100質量部に対して、通常、100質量部以下、好ましくは80質量部以下、より好ましくは60質量部以下、さらに好ましくは40質量部以下、特に好ましくは20質量部以下である。
本発明の不溶化材は、例えば、粉体またはスラリー(粉体と水の混合物)の形態を有することができる。
The insolubilizing material of the present invention optionally contains at least one other component selected from calcium carbonate, calcium phosphate, zeolite, polyaluminum chloride, aluminum hydroxide, aluminum sulfate, silica powder, magnesium hydroxide, and bentonite. It may contain more than seeds.
The amount of other components added may be within a range that does not impair the effects of the present invention, and is usually 100 parts by mass or less, preferably 80 parts by mass, relative to a total of 100 parts by mass of the magnesium oxide-containing substance and basic magnesium carbonate. It is not more than 60 parts by mass, more preferably not more than 40 parts by mass, and particularly preferably not more than 20 parts by mass.
The insolubilizing material of the present invention can have, for example, the form of powder or slurry (a mixture of powder and water).
本発明の固化材を用いた土壌の固化処理は、上述した固化材を、土壌に添加し、混合することで行なうことができる。
固化処理の対象となる土壌は、特に限定されるものではないが、固化処理後の土壌の強度(例えば、一軸圧縮強さ)をより大きくすることができる観点から、好ましくは火山灰質粘性土である。
土壌への固化材の添加量は、対象となる土壌の性状、施工条件、固化処理後の土壌に求められる強度等によっても異なるが、固化処理の対象となる土壌1m3当たり、好ましくは10~300kg、より好ましくは20~200kg、特に好ましくは25~150kgである。該量が10kg以上であれば、固化処理後の土壌の強度(例えば、一軸圧縮強さ)をより大きくすることができる。該量が300kg以下であれば、コストの増大を防ぐことができる。
Soil solidification treatment using the solidifying material of the present invention can be carried out by adding the above-described solidifying material to soil and mixing.
The soil to be solidified is not particularly limited, but from the viewpoint of increasing the strength of the soil after solidification (for example, unconfined compressive strength), volcanic ash clay is preferable. be.
The amount of solidification material to be added to the soil varies depending on the properties of the target soil, construction conditions, the strength required for the soil after solidification, etc., but it is preferably 10 to 10 m3 per 1 m 3 of the soil to be solidified. 300 kg, more preferably 20-200 kg, particularly preferably 25-150 kg. If the amount is 10 kg or more, the strength (for example, unconfined compressive strength) of the soil after solidification treatment can be increased. If the amount is 300 kg or less, an increase in cost can be prevented.
土壌への固化材の添加及び混合の方法としては、対象となる土壌に固化材を粉体のまま添加し、混合するドライ添加や、固化材に水を加えてスラリーとし、該スラリーを添加し、混合するスラリー添加が挙げられる。スラリー添加の場合の水/固化材の質量比は、好ましくは0.6~1.5、より好ましくは0.8~1.2である。 As a method of adding and mixing the solidifying material to the soil, the solidifying material is added to the soil as it is in powder form and mixed. , slurry addition to mix. The mass ratio of water/solidifying agent when slurry is added is preferably 0.6 to 1.5, more preferably 0.8 to 1.2.
以下、本発明を実施例により具体的に説明するが、本発明はこれらの実施例に限定されるものではない。
[使用材料]
(1)塩基性炭酸マグネシウム微粉末(4MgCO3・Mg(OH)2・4H2O);BET比表面積:38.5m2/g、見掛け比重:0.25g/cm3
(2)ドロマイト微粉末(Ca・Mg(CO3)2:炭酸マグネシウムを含む組成の鉱物);ブレーン比表面積:3,150cm2/g
(3)軽焼マグネシア微粉末(表1中、「MgO」と示す。);酸化マグネシウムの含有率:88質量%、ブレーン比表面積:2,650cm2/g
(4)石膏
(5)セメント系固化材;汎用型固化材
(6)土壌;火山灰質粘性土(関東ローム);含水比:119.4%
EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited to these examples.
[Materials used]
(1) Basic magnesium carbonate fine powder (4MgCO 3 ·Mg(OH) 2 · 4H 2 O); BET specific surface area: 38.5 m 2 /g, apparent specific gravity: 0.25 g/cm 3
(2) Dolomite fine powder (Ca.Mg(CO 3 ) 2 : a mineral with a composition containing magnesium carbonate); Blaine specific surface area: 3,150 cm 2 /g
(3) Lightly burned magnesia fine powder (shown as “MgO” in Table 1); content of magnesium oxide: 88% by mass, Blaine specific surface area: 2,650 cm 2 /g
(4) Gypsum (5) Cement-based solidifying material; general-purpose solidifying material (6) Soil; volcanic ash cohesive soil (Kanto loam); water content: 119.4%
[実施例1~3]
上記材料を、表1に示す配合割合で混合して固化材を得た。土壌に該固化材を、土壌1m3に対して100kgとなる量で添加し、ホバートミキサを用いて3分間混合して、固化処理土を得た。得られた固化処理土の材齢7日及び28日における一軸圧縮強さを「JIS R 1216:2009(土の一軸圧縮試験方法)」に準拠して測定した。
[比較例1]
固化材として、軽焼マグネシアのみからなる固化材を用いる以外は、実施例1と同様にして、固化処理土を得て、その一軸圧縮強さを測定した。
[比較例2]
固化材として、セメント系固化材を用いる以外は、実施例1と同様にして、固化処理土を得て、その一軸圧縮強さを測定した。
[比較例3]
塩基性炭酸マグネシウムの代わりに、ドロマイトを用いる以外は、実施例1と同様にして、固化処理土を得て、その一軸圧縮強さを測定した。
結果を表1に示す。
[Examples 1 to 3]
The above materials were mixed at the mixing ratio shown in Table 1 to obtain a solidifying material. The solidifying material was added to the soil in an amount of 100 kg per 1 m 3 of soil and mixed for 3 minutes using a Hobart mixer to obtain solidified soil. The unconfined compressive strength of the obtained solidified soil at 7 days and 28 days was measured according to "JIS R 1216:2009 (test method for unconfined compression of soil)".
[Comparative Example 1]
Solidified soil was obtained in the same manner as in Example 1, except that a solidifying material consisting only of light-burnt magnesia was used as the solidifying material, and the unconfined compressive strength was measured.
[Comparative Example 2]
Solidified soil was obtained in the same manner as in Example 1 except that a cement-based solidifying material was used as the solidifying material, and the unconfined compressive strength was measured.
[Comparative Example 3]
Solidified soil was obtained in the same manner as in Example 1, except that dolomite was used instead of basic magnesium carbonate, and its unconfined compressive strength was measured.
Table 1 shows the results.
[実施例4~5]
固化材として、上記材料を表2に示す配合割合で混合してなるものを用いる以外は、実施例1と同様にして、固化処理土を得て、その一軸圧縮強さを測定した。
結果を表2に示す。
[Examples 4-5]
Solidified soil was obtained in the same manner as in Example 1, except that the above-mentioned materials were mixed at the mixing ratio shown in Table 2 as the solidifying material, and the unconfined compressive strength was measured.
Table 2 shows the results.
表1から、本発明の不溶化材を用いた固化処理土(実施例1~3)の一軸圧縮強さ(材齢7日:778~1,058kN/m2、材齢28日:915~1,233kN/m2)は、軽焼マグネシアのみからなる固化材を用いた固化処理土(比較例1)の一軸圧縮強さ(材齢7日:671kN/m2、材齢28日:848kN/m2)や、セメント系固化材を用いた固化処理土(比較例2)の一軸圧縮強さ(材齢7日:26kN/m2、材齢28日:34kN/m2)や、塩基性炭酸マグネシウムの代わりにドロマイトを用いた固化材を用いた固化処理土(比較例3)の一軸圧縮強さ(材齢7日:608kN/m2、材齢28日:802kN/m2)よりも大きいことがわかる。
なお、表1に示すとおり、比較例3で用いたドロマイトの量は、MgCO3換算値によると、実施例2(1.9質量%)と実施例3(2.8質量%)の中間の塩基性炭酸マグネシウムの量に相当する。
From Table 1, the uniaxial compressive strength of the solidified soil (Examples 1 to 3) using the insolubilizing material of the present invention (7 days of age: 778 to 1,058 kN/m 2 , 28 days of age: 915 to 1 , 233 kN/m 2 ) is the uniaxial compressive strength of the solidified soil (Comparative Example 1) using a solidifying material consisting only of light-burnt magnesia (7 days old: 671 kN/m 2 , 28 days old: 848 kN/ m 2 ), the uniaxial compressive strength of the solidified soil using a cement-based solidifying material (Comparative Example 2) (7 days old: 26 kN/m 2 , 28 days old: 34 kN/m 2 ), basicity than the uniaxial compressive strength (7 days old: 608 kN/m 2 , 28 days old: 802 kN/m 2 ) of the solidified soil (Comparative Example 3) using dolomite as a solidifying material instead of magnesium carbonate I know it's big.
As shown in Table 1, the amount of dolomite used in Comparative Example 3 was intermediate between Example 2 (1.9% by mass) and Example 3 (2.8% by mass) according to the MgCO3 conversion value. Corresponds to the amount of basic magnesium carbonate.
特に、塩基性炭酸マグネシウムの含有率が10質量%である不溶化材を用いた固化処理土(実施例2)の一軸圧縮強さ(材齢7日:1,058kN/m2、材齢28日:1,233kN/m2)は、塩基性炭酸マグネシウムの含有率が、5質量%または15質量%である不溶化材を用いた固化処理土(実施例1、3)の一軸圧縮強さ(材齢7日:778~849kN/m2、材齢28日:915~1,057kN/m2)よりも大きく、塩基性炭酸マグネシウムの含有率が10質量%である不溶化材は、固化処理後の土壌の強度をより大きくしうることがわかる。 In particular, the uniaxial compressive strength (age 7 days: 1,058 kN/m 2 , age 28 days) of solidified soil (Example 2) using an insolubilizing material having a basic magnesium carbonate content of 10% by mass : 1,233 kN/m 2 ) is the uniaxial compressive strength (material 7 days old: 778 to 849 kN/m 2 , 28 days old: 915 to 1,057 kN/m 2 ), and the content of basic magnesium carbonate is 10% by mass. It can be seen that the strength of the soil can be increased.
また、表2から、軽焼マグネシアと塩基性炭酸マグネシウムと石膏を含む固化材を用いた固化処理土(実施例4~5)の一軸圧縮強さ(材齢7日:1,101~1,162kN/m2、材齢28日:1124~1,265kN/m2)は、実施例1~3における固化処理土の一軸圧縮強さ(材齢7日:778~1,058kN/m2、材齢28日:915~1,233kN/m2)や、比較例1~2における固化処理土の一軸圧縮強さ(材齢7日:26~671kN/m2、材齢28日:34~848kN/m2)よりも大きいことがわかる。 In addition, from Table 2, the uniaxial compressive strength of solidified soil (Examples 4 to 5) using a solidifying material containing light burnt magnesia, basic magnesium carbonate and gypsum (age 7 days: 1,101 to 1, 162 kN/m 2 , 28 days old: 1124 to 1,265 kN/m 2 ) is the uniaxial compressive strength of the solidified soil in Examples 1 to 3 (7 days old: 778 to 1,058 kN/m 2 , 28 days old: 915 to 1,233 kN/m 2 ) and the uniaxial compressive strength of the solidified soil in Comparative Examples 1 and 2 (7 days old: 26 to 671 kN/m 2 , 28 days old: 34 to 848 kN/m 2 ).
Claims (4)
上記固化材が、酸化マグネシウム含有物質と下記化学式:
mMgCO 3 ・Mg(OH) 2 ・nH 2 O
(上記化学式中、mは3~5の整数であり、nは3~7の整数である。)
で表される塩基性炭酸マグネシウムを含み、
上記酸化マグネシウム含有物質と上記塩基性炭酸マグネシウムの合計量中の、上記塩基性炭酸マグネシウムの量の割合が、7.0~12.0質量%であり、
上記酸化マグネシウム含有物質中の酸化マグネシウムの含有率が、85質量%以上であることを特徴とする土壌の固化処理方法。 A soil solidification method in which a solidification material is added to the soil and mixed,
The solidifying material is a magnesium oxide-containing substance and the following chemical formula :
mMgCO3.Mg ( OH ) 2.nH2O _ _
(In the above chemical formula, m is an integer of 3 to 5, and n is an integer of 3 to 7.)
Contains basic magnesium carbonate represented by
The ratio of the amount of the basic magnesium carbonate in the total amount of the magnesium oxide-containing substance and the basic magnesium carbonate is 7.0 to 12.0% by mass,
A soil solidification method, wherein the content of magnesium oxide in the magnesium oxide-containing substance is 85% by mass or more.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018155371A JP7120847B2 (en) | 2018-08-22 | 2018-08-22 | Soil solidification treatment method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018155371A JP7120847B2 (en) | 2018-08-22 | 2018-08-22 | Soil solidification treatment method |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2020029502A JP2020029502A (en) | 2020-02-27 |
JP7120847B2 true JP7120847B2 (en) | 2022-08-17 |
Family
ID=69623845
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2018155371A Active JP7120847B2 (en) | 2018-08-22 | 2018-08-22 | Soil solidification treatment method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP7120847B2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7265691B2 (en) * | 2021-02-22 | 2023-04-26 | 花王株式会社 | Soil improvement method |
CN113731155A (en) * | 2021-09-29 | 2021-12-03 | 大连海事大学 | Carbon dioxide emission reduction and utilization device and method for dredging ship |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003082348A (en) | 2001-09-06 | 2003-03-19 | Odessa Technos Co Ltd | System for conditioning weak soil in neutral region into soil capable of giving strength |
JP2003082351A (en) | 2001-09-06 | 2003-03-19 | Odessa Technos Co Ltd | Neutral solidifying material for soil conditioning |
JP2011525885A (en) | 2008-06-26 | 2011-09-29 | ノヴァセム リミテッド | Binder composition |
-
2018
- 2018-08-22 JP JP2018155371A patent/JP7120847B2/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003082348A (en) | 2001-09-06 | 2003-03-19 | Odessa Technos Co Ltd | System for conditioning weak soil in neutral region into soil capable of giving strength |
JP2003082351A (en) | 2001-09-06 | 2003-03-19 | Odessa Technos Co Ltd | Neutral solidifying material for soil conditioning |
JP2011525885A (en) | 2008-06-26 | 2011-09-29 | ノヴァセム リミテッド | Binder composition |
Non-Patent Citations (1)
Title |
---|
山田 哲司ら著,酸化マグネシウムの製造方法が改良土の性質に及ぼす影響について,土木学会論文集C(地圏工学),2012年,Vol.68, No.4,pp.732-741 |
Also Published As
Publication number | Publication date |
---|---|
JP2020029502A (en) | 2020-02-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5068245B2 (en) | Insolubilized material | |
US10968108B2 (en) | Method for the manufacture of calcium silicate hydrate used as hardening accelerator in concrete and cement-based materials, calcium silicate hydrate manufactured with said method | |
JP5599061B2 (en) | Neutral solidifying material additive, neutral solidifying material and method for suppressing elution of heavy metals | |
WO2022097495A1 (en) | Fast-setting mixed material and spraying material | |
JP7120847B2 (en) | Soil solidification treatment method | |
JP6547455B2 (en) | Ground improvement material and ground improvement method | |
JP6793270B1 (en) | Fast-setting admixture and spray material | |
JP6355946B2 (en) | Selenium insolubilizing material for soil and method for insolubilizing selenium in soil | |
JP6538356B2 (en) | Insolubilizing material and insolubilizing slurry | |
JP5604801B2 (en) | Soil solidifying material and soil solidifying method | |
JPS6336840B2 (en) | ||
JP3818802B2 (en) | Cement admixture and cement composition | |
JP4107773B2 (en) | Cement admixture and cement composition | |
JP4630655B2 (en) | Mixed solidification material for soil | |
JP6465604B2 (en) | Insolubilized slurry | |
JP6536215B2 (en) | Ground improvement material and ground improvement method | |
JP4561190B2 (en) | Solidification method of target soil | |
JP5689605B2 (en) | Ground improvement material and ground improvement method | |
JP2021017376A (en) | Expandable composition for cement, and cement composition | |
JP4073051B2 (en) | Soil stabilizer | |
JP6166153B2 (en) | Ground improvement material | |
JP3007905B2 (en) | Soil improvement method | |
JP2001064056A (en) | Cement admixture and cement composition | |
JP3853118B2 (en) | Cement admixture and cement composition | |
JP7062225B2 (en) | Strength-enhancing agent, its manufacturing method, and Portland cement strength-enhancing method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20210427 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20220218 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20220308 |
|
A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20220428 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20220630 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20220802 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20220804 |
|
R150 | Certificate of patent or registration of utility model |
Ref document number: 7120847 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |