JP7231513B2 - fluidized sand composition - Google Patents

fluidized sand composition Download PDF

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JP7231513B2
JP7231513B2 JP2019143624A JP2019143624A JP7231513B2 JP 7231513 B2 JP7231513 B2 JP 7231513B2 JP 2019143624 A JP2019143624 A JP 2019143624A JP 2019143624 A JP2019143624 A JP 2019143624A JP 7231513 B2 JP7231513 B2 JP 7231513B2
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sand
fluidized sand
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furnace slag
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英典 高田
竹史 伊藤
雅大 永石
祐司 山下
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Fudo Tetra Corp
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    • YGENERAL 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
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本発明は、打設時には十分な流動性を有し、脱水できる土壌又は脱水できない土壌中であっても、打設後、掘削や矢板の打込みなどに支障のない適度な強度を有する流動化砂用混合材、改良流動化砂の製造方法、流動化砂組成物及び流動化砂組成物の製造方法に関するものである。 The fluidized sand of the present invention has sufficient fluidity at the time of placement, and even in soil that can be dehydrated or in soil that cannot be dehydrated, and has an appropriate strength that does not interfere with excavation or driving of sheet piles after placement. The present invention relates to an admixture for sand, a method for producing improved fluidized sand, a fluidized sand composition, and a method for producing a fluidized sand composition.

締固め砂杭造成工法は、特公昭62-25808号公報などに開示されているように、中空管を地盤中の設計深度まで貫入した後、地表まで引き抜く過程で、前記中空管を所定高さ引き抜き管内に投入された砂等を排出する引き抜き工程と、前記中空管を再び貫入して排出砂等を締固める再貫入工程とを繰り返して行うことにより、所定の強度に締固めた砂杭を造成し、地盤を改良するものである。 As disclosed in Japanese Patent Publication No. 62-25808, etc., in the compaction sand pile construction method, after penetrating a hollow pipe to a design depth in the ground, the hollow pipe is pulled out to the ground surface. By repeatedly performing a drawing step of discharging sand, etc. thrown into the height drawing pipe and a re-penetration step of penetrating the hollow pipe again and compacting the discharged sand, etc., it was compacted to a predetermined strength. Sand piles are created to improve the ground.

締固め砂杭造成工法には、例えばラックとピニオンを使用した強制昇降装置による回転圧入施工により、中空管の貫入及び引き抜きを行う静的締固め砂杭工法(例えば特開平08-284146号公報)、振動する中空管を使用し、貫入、引き抜き及び打ち戻しを繰り返す打ち戻し式サンドコンパクション工法などがある。 As a compaction sand pile construction method, for example, a static compaction sand pile construction method in which a hollow pipe is penetrated and pulled out by rotary press-in construction with a forced lifting device using a rack and pinion (for example, Japanese Patent Application Laid-Open No. 08-284146) ), and a hammering-type sand compaction method that uses a vibrating hollow tube and repeats penetration, extraction, and hammering.

いずれの工法も地表に起立又は傾斜させた地中貫入用中空管に砂杭材料を投入するため、砂杭造成区域にはタイヤショベルなどの砂杭材料供給手段が稼動するスペースが必要であった。しかし、既設構造物の直下又は直近が砂杭造成区域となる場合、タイヤショベルなどの砂杭材料供給手段が稼動するスペースを確保できず、従来の砂杭造成工法を適用することができないという問題があった。 In either construction method, the sand pile material is put into a hollow pipe for penetrating the ground that is erected or inclined on the ground surface, so a space for sand pile material supply means such as a tire shovel is required in the sand pile construction area. rice field. However, if the sand pile construction area is directly under or near the existing structure, it is not possible to secure a space for sand pile material supply means such as a tire shovel to operate, and the conventional sand pile construction method cannot be applied. was there.

これを解決するものとして、特開2010-13885号公報には、地盤改良に用いる砂杭材料に遅効性塑性化剤を含有する砂杭材料流動化物を、流動状態を保持したまま地盤中に圧入し、地盤中で塑性化させることを特徴とする砂杭造成工法が開示されている。また、特開2018-53701号公報には、材料砂に含水比調整用水と共に流動化剤を加えて圧送ポンプにより配管を通して移送可能に処理される地盤改良用の流動化砂において、前記材料砂に対し該材料砂に含まれる、前記流動化剤の阻害要因となる金属イオン等の陽イオンを電荷中和可能なイオン電荷中和用添加剤を混ぜた後、前記流動化剤を混入していることを特徴とする流動化砂が開示されている。これら砂杭材料流動化物や流動化砂によれば、既設構造物の直下又は直近など砂杭材料供給手段が稼動するスペースを確保できない狭い砂杭造成地盤区域であっても、該地盤中で脱水され、流動化剤が不溶化し、塑性化する。 As a solution to this, JP 2010-13885 discloses a sand pile material fluidized material containing a slow-acting plasticizer in the sand pile material used for ground improvement, and is pressed into the ground while maintaining the fluid state. Then, a sand pile construction method characterized by plasticizing in the ground is disclosed. In addition, Japanese Patent Application Laid-Open No. 2018-53701 describes fluidized sand for ground improvement that is processed so that it can be transferred through a pipe by a pressure pump by adding a fluidizing agent together with water for adjusting the water content ratio to the material sand. On the other hand, the fluidizing agent is mixed after an ion charge neutralizing additive capable of neutralizing the cations such as metal ions that inhibit the fluidizing agent contained in the material sand is mixed. Disclosed is a fluidized sand characterized by: According to these fluidized sand pile materials and fluidized sand, even in a narrow sand pile formation ground area where a space for sand pile material supply means to operate cannot be secured, such as directly under or near an existing structure, dehydration in the ground , the fluidizer becomes insoluble and plasticized.

特公昭62-25808号公報Japanese Patent Publication No. 62-25808 特開2010-13885号公報(請求項1)JP 2010-13885 A (Claim 1) 特開2018-53701号公報(請求項1)Japanese Patent Application Laid-Open No. 2018-53701 (Claim 1)

しかしながら、従来の流動化砂は、圧入圧力により脱水ができれば砂としての強度を発現するが、脱水ができない場合はほとんど強度が発現しない。従って、排水が望めない地盤や圧入脱水を行わない施工では、十分な強度が発現できないという問題がある。そこで、これら脱水できない地盤中であっても、目的に応じた任意の強度を発現できる流動化砂の登場が望まれていた。 However, conventional fluidized sand develops strength as sand if it can be dewatered by injection pressure, but hardly develops strength if it cannot be dewatered. Therefore, there is a problem that sufficient strength cannot be exhibited in the ground where drainage cannot be expected or in construction without press-in dehydration. Therefore, it has been desired to develop a fluidized sand that can exhibit any strength according to the purpose even in such ground that cannot be dewatered.

従って、本発明の目的は、打設時には十分な流動性を有し、脱水できる土壌あるいは脱水できない土壌中であっても、打設後、目的に応じた任意の強度を発現できる、又は周辺の硬質地盤と同等の強度を有する流動化砂用混合材、改良流動化砂の製造方法、流動化砂組成物及び流動化砂組成物の製造方法を提供することにある。 Therefore, the object of the present invention is to develop any strength according to the purpose after placing, even in soil that has sufficient fluidity at the time of placement and can be dehydrated or in soil that cannot be dehydrated. An object of the present invention is to provide a fluidized sand mixture having strength equivalent to that of hard ground, a method for producing improved fluidized sand, a fluidized sand composition, and a method for producing a fluidized sand composition.

すなわち、本発明は、上記従来の課題を解決するものであり、消石灰及び石膏から選択される1種又は2種、及び高炉スラグ微粉末を含有することを特徴とする流動化砂用混合材を提供するものである。 That is, the present invention solves the above-mentioned conventional problems, and provides a fluidized sand mixture characterized by containing one or two selected from hydrated lime and gypsum, and ground granulated blast furnace slag. It provides.

また、本発明は、該消石灰及び/又は石膏の配合量は、該高炉スラグ微粉末100重量部に対して、10~200重量部であることを特徴とする前記流動化砂用混合材を提供するものである。 Further, the present invention provides the above-mentioned admixture for fluidized sand, characterized in that the blending amount of said slaked lime and/or gypsum is 10 to 200 parts by weight with respect to 100 parts by weight of said ground granulated blast furnace slag. It is something to do.

また、本発明は、該高炉スラグ微粉末の比表面積が、2,750~10,000cm/gであることを特徴とする前記流動化砂用混合材を提供するものである。 The present invention also provides the above-mentioned admixture for fluidized sand, characterized in that the ground granulated blast furnace slag has a specific surface area of 2,750 to 10,000 cm 2 /g.

また、本発明は、地盤への充填前の流動化砂に、消石灰及び石膏から選択される1種又は2種、及び高炉スラグ微粉末を含有する流動化砂用混合材を混合することを特徴とする改良流動化砂の製造方法を提供するものである。 Further, the present invention is characterized in that the fluidized sand before filling the ground is mixed with a fluidized sand mixture containing one or two selected from hydrated lime and gypsum and ground granulated blast furnace slag. A method for producing an improved fluidized sand is provided.

また、本発明は、地盤への充填前の流動化砂に、消石灰及び石膏から選択される1種又は2種、及び高炉スラグ微粉末を混合することを特徴とする改良流動化砂の製造方法を提供するものである。 Further, the present invention is a method for producing improved fluidized sand, characterized in that one or two selected from hydrated lime and gypsum and ground granulated blast furnace slag are mixed with fluidized sand before filling into ground. It provides

また、本発明は、該流動化砂中の乾燥状態の材料砂100重量部に対して、高炉スラグ微粉末を1~20重量部、配合することを特徴とする前記改良流動化砂の製造方法を提供するものである。 Further, the present invention is characterized in that 1 to 20 parts by weight of ground granulated blast furnace slag is blended with 100 parts by weight of dry material sand in the fluidized sand. It provides

また、本発明は、該流動化砂は、材料砂、含水比調製用水及び流動化剤を含有することを特徴とする前記改良流動化砂の製造方法を提供するものである。 The present invention also provides a method for producing improved fluidized sand, characterized in that the fluidized sand contains material sand, water for adjusting the water content, and a fluidizing agent.

また、本発明は、該改良流動化砂は、製造後1時間以内でのテクスチャー試験における貫入応力が、50,000Pa以下であることを特徴とする前記改良流動化砂の製造方法を提供するものである。 The present invention also provides a method for producing improved fluidized sand, characterized in that the improved fluidized sand has a penetration stress of 50,000 Pa or less in a texture test within one hour after production. is.

また、本発明は、消石灰及び石膏から選択される1種又は2種、材料砂、含水比調製用水、流動化剤及び高炉スラグ微粉末を含有することを特徴とする流動化砂組成物を提供するものである。 The present invention also provides a fluidized sand composition comprising one or two selected from slaked lime and gypsum, material sand, water for adjusting the water content, a fluidizing agent, and ground granulated blast furnace slag. It is something to do.

また、本発明は、該流動化砂組成物中の材料砂100重量部に対して、高炉スラグ微粉末を1~20重量部、配合することを特徴とする前記流動化砂組成物を提供するものである。 The present invention also provides a fluidized sand composition characterized by blending 1 to 20 parts by weight of ground granulated blast furnace slag with respect to 100 parts by weight of the material sand in the fluidized sand composition. It is.

また、本発明は、該流動化砂組成物は、製造後1時間以内でのテクスチャー試験における貫入応力が、50,000Pa以下であることを特徴とする前記流動化砂組成物を提供するものである。 The present invention also provides the fluidized sand composition, characterized in that the penetration stress in a texture test within 1 hour after production is 50,000 Pa or less. be.

また、本発明は、消石灰及び石膏から選択される1種又は2種、材料砂、含水比調製用水、流動化剤及び高炉スラグ微粉末を混合することを特徴とする流動化砂組成物の製造方法を提供するものである。 Further, the present invention relates to the production of a fluidized sand composition characterized by mixing one or two selected from slaked lime and gypsum, material sand, water for adjusting the water content ratio, a fluidizing agent, and ground granulated blast furnace slag. It provides a method.

また、本発明は、消石灰及び石膏から選択される1種又は2種、材料砂及び高炉スラグ微粉末を混合する第1工程と、該第1工程で得られた混合物と、含水比調製用水及び流動化剤を混合する第2工程とを行うことを特徴とする前記流動化砂組成物の製造方法を提供するものである。 In addition, the present invention provides a first step of mixing one or two selected from slaked lime and gypsum, material sand and ground granulated blast furnace slag, the mixture obtained in the first step, water for adjusting the water content ratio, and and a second step of mixing a fluidizing agent.

本発明によれば、打設時には十分な流動性を有し、脱水できない土壌中であっても、打設後、目的に応じた任意の強度を発現できる、又は周辺の硬質地盤と同等の強度を有する流動化砂組成物を提供できる。また、従来の流動化砂に添加するだけで、上記性能を発現する流動化砂用混合材を提供できる。 According to the present invention, it has sufficient fluidity at the time of placing, and even in soil that cannot be dehydrated, it is possible to develop arbitrary strength according to the purpose after placing, or strength equivalent to that of the surrounding hard ground. can provide a fluidized sand composition having In addition, it is possible to provide a mixture for fluidized sand that exhibits the above-mentioned performance simply by adding it to conventional fluidized sand.

本発明の流動化砂組成物を使用した圧入式砂充填装置の概略図を示す。1 shows a schematic diagram of a press-fit sand filling apparatus using the fluidized sand composition of the present invention; FIG.

(流動化砂用混合材)
本発明において、流動化砂用混合材(以下、単に「混合材」とも言う。)は、消石灰及び石膏から選択される1種又は2種及び高炉スラグ微粉末を含有する。
(Admixture for fluidized sand)
In the present invention, the admixture for fluidized sand (hereinafter also simply referred to as "admixture") contains one or two selected from hydrated lime and gypsum and ground granulated blast furnace slag.

混合材において、高炉スラグ微粉末は、製鋼工程で生じる粉粒状の副産物であり、CaO、SiO、Al、MgOが主成分である。高炉スラグには、除冷スラグと水砕スラグがあり、この中、水砕スラグが使用できる。水砕スラグとは、溶融状態の高炉スラグを加圧水で急冷することにより生成されるガラス質(非結晶)で粒状のものを言う。 In the mixed material, ground granulated blast furnace slag is a powdery by-product generated in the steelmaking process, and its main components are CaO, SiO 2 , Al 2 O 3 and MgO. Blast furnace slag includes decooled slag and water granulated slag, and water granulated slag can be used. Water granulated slag refers to glassy (amorphous) granular slag produced by quenching molten blast furnace slag with pressurized water.

高炉スラグ微粉末は、高炉スラグ微粉末は、比表面積が、2,750~10,000cm/gのものが好ましい。これにより、高炉スラグ微粉末は、例えば、公知の流動化砂に添加された際、消石灰又は石膏の存在により、反応が促進され、凝結して、適度の強度を発現する。従って、高炉スラグ微粉末単独では、適度の強度が発現できない。 The ground granulated blast furnace slag preferably has a specific surface area of 2,750 to 10,000 cm 2 /g. As a result, when the ground granulated blast furnace slag is added to, for example, known fluidized sand, the presence of hydrated lime or gypsum accelerates the reaction, coagulates, and develops appropriate strength. Therefore, ground granulated blast furnace slag alone cannot exhibit adequate strength.

消石灰は、水酸化カルシウムであり、生石灰を水または水蒸気で消和してつくられる。建築用消石灰、肥料用消石灰、工業用消石灰などいずれも粉末状のものが使用できる。消石灰の配合量は、高炉スラグ微粉末100重量部に対して、10重量部~200重量部、好ましくは20重量部~100重量部である。消石灰の配合量が多過ぎると、流動化砂のpHがアルカリとなり、アルカリ分が溶出することで環境に対する影響の点で好ましくなく、また少な過ぎると、高炉スラグ微粉末との反応が促進されない点で好ましくない。 Slaked lime is calcium hydroxide and is made by slaked lime with water or steam. Slaked lime for construction, slaked lime for fertilizers, slaked lime for industrial use, and the like can all be used in powder form. The amount of slaked lime is 10 to 200 parts by weight, preferably 20 to 100 parts by weight, per 100 parts by weight of ground granulated blast furnace slag. If the amount of slaked lime is too large, the pH of the fluidized sand becomes alkaline, and the alkaline content is eluted, which is not preferable in terms of environmental impact. I don't like it.

石膏としては、特に限定されず、二水石膏、半水石膏、無水石膏が挙げられ、この内、半石膏が入手し易い点で好ましい。石膏の具体例としては、天然石膏、排煙脱硫処理によって副生する石膏、天然無水石膏、ふっ酸の製造過程で副産するふっ酸無水石膏等が挙げられる。石膏の配合量は、高炉スラグ微粉末100重量部に対して、10重量部~200重量部、好ましくは20重量部~100重量部である。石膏の配合量が多過ぎると、経済性の点で好ましくなく、また少な過ぎると、高炉スラグ微粉末との反応が促進されない点で好ましくない。 The gypsum is not particularly limited, and includes gypsum dihydrate, gypsum hemihydrate, and gypsum anhydrite. Of these, gypsum hemihydrate is preferred because it is readily available. Specific examples of gypsum include natural gypsum, gypsum by-produced in flue gas desulfurization treatment, natural anhydrite, hydrofluoric anhydride gypsum by-produced in the process of producing hydrofluoric acid, and the like. The amount of gypsum to be added is 10 to 200 parts by weight, preferably 20 to 100 parts by weight, per 100 parts by weight of ground granulated blast furnace slag. If the amount of gypsum is too large, it is not preferable from the economic point of view.

混合材は、高炉スラグ微粉末、消石灰及び石膏の3成分を含むものであってもよい。また、上記必須の成分以外に、水などの第3成分を含んでいてもよい。混合材は、粉末状であることが、ハンドリングがよい点で好ましい。 The mixed material may contain three components of ground granulated blast furnace slag, hydrated lime and gypsum. In addition to the above essential components, a third component such as water may be included. It is preferable that the mixed material is in the form of powder because it is easy to handle.

混合材が添加される流動化砂としては、材料砂、含水比調製用水及び流動化剤を含有する公知のものが挙げられる。すなわち、公知の流動化砂は、流動状態を保持したまま地盤中に圧入され、地盤中の脱水環境下で塑性化させるものであれば、特に制限されない。この流動化砂は、地盤中、圧入圧力により脱水ができれば砂としての強度を発現するが、脱水ができない場合はほとんど強度が発現しない。 As the fluidizing sand to which the admixture is added, known sand containing material sand, water for adjusting the water content and fluidizing agent can be used. That is, the known fluidized sand is not particularly limited as long as it is pressed into the ground while maintaining its fluid state and is plasticized under the dehydrated environment in the ground. This fluidized sand develops strength as sand if it can be dewatered by injection pressure in the ground, but hardly develops strength if it cannot be dewatered.

混合材が添加される流動化砂で使用される材料砂としては、従来の砂杭造成工法で使用されてきた公知の材料と同様のものであり、例えば、砂、シルトや礫を含む砂、砕石及びスラグ等が挙げられる。材料砂としては、好ましくは、粒径が0.074~2.0mm程度を主体としたものであり、最大粒径は、好ましくは9.5mmである。 The material sand used in the fluidized sand to which the mixed material is added is the same as known materials that have been used in the conventional sand pile construction method. crushed stone, slag, and the like. The material sand preferably has a particle size of approximately 0.074 to 2.0 mm, and the maximum particle size is preferably 9.5 mm.

混合材が添加される流動化砂で使用される流動化剤は、砂の粒子間の間隙水の粘性を高め、飽和状態で砂と水の分離を抑制してポンプ圧送性を向上させる添加剤であり、具体的には、アニオン系高分子凝集剤、ノニオン系高分子凝集剤、カチオン系高分子凝集剤などである。アニオン系高分子凝集剤としては、イタコン酸、マレイン酸、アクリル酸、メタクリル酸、アクリルアミド2-メチルプロパンスルフォン酸、ビニルスルフォン酸、スチレンスルフォン酸などの単独重合体あるいはアクリルアミドとの共重合体が挙げられる。 The fluidizing agent used in the fluidized sand to which the admixture is added is an additive that increases the viscosity of the pore water between sand particles and suppresses the separation of sand and water in a saturated state to improve pumpability. Specifically, they include anionic polymer flocculants, nonionic polymer flocculants, cationic polymer flocculants, and the like. Examples of anionic polymer flocculants include homopolymers of itaconic acid, maleic acid, acrylic acid, methacrylic acid, acrylamide 2-methylpropanesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, and copolymers with acrylamide. be done.

(改良流動化砂の製造方法)
次に、本発明の改良流動化砂の製造方法について説明する。改良流動化砂は、地盤への充填前の流動化砂に、上記混合材を混合することで得られ、あるいは地盤への充填前の流動化砂に、消石灰及び石膏から選択される1種又は2種、及び高炉スラグ微粉末を混合することで得られる。地盤への充填前の流動化砂に、消石灰及び石膏から選択される1種又は2種、及び高炉スラグ微粉末を添加する場合、消石灰及び石膏から選択される1種又は2種と高炉スラグ微粉末の混合は、別々の混合であってもよく、混合順序は制限されない。
混合材の配合量は、流動化砂中の乾燥状態の材料砂100重量部に対して、高炉スラグ微粉末の配合量が1~20重量部となるように配合することが、消石灰又は石膏の存在により、反応が促進され、凝結して、適度の強度を発現する点で好ましい。高炉スラグ微粉末の配合量が多過ぎると、圧送性が低下する点で好ましくなく、また少な過ぎると、強度が発現しない点で好ましくない。なお、流動化砂中の材料砂の配合量は、流動砂の含水比を測定することで、乾燥状態の材料砂の重量を求めればよい。
(Method for producing improved fluidized sand)
Next, the method for producing the improved fluidized sand of the present invention will be described. The improved fluidized sand is obtained by mixing the above mixed material with the fluidized sand before filling the ground, or one selected from hydrated lime and gypsum, or It is obtained by mixing two types and ground granulated blast furnace slag. When one or two selected from hydrated lime and gypsum and ground blast furnace slag are added to the fluidized sand before filling the ground, one or two selected from hydrated lime and gypsum and ground blast furnace slag are added. The mixing of the powders may be separate mixings and the order of mixing is not restricted.
The blending amount of the mixed material is such that the blending amount of the ground granulated blast furnace slag is 1 to 20 parts by weight with respect to 100 parts by weight of the dry material sand in the fluidized sand. Its presence is preferable in that it accelerates the reaction, coagulates, and develops an appropriate strength. If the amount of the ground granulated blast furnace slag is too large, the pumpability will be lowered, and if it is too small, the strength will not be developed. The amount of material sand in the fluidized sand can be obtained by measuring the water content of the fluidized sand to determine the weight of the material sand in a dry state.

本発明の改良流動化砂の製造方法において、得られた改良流動化砂は、製造後1時間以内のテクスチャー試験における貫入応力が、50,000Pa以下、好ましくは30,000Pa以下である。これにより、改良流動化砂は、高炉スラグ微粉末等が配合されていても、打設時には十分な流動性を有する。また、製造後28日の一軸圧縮強さは100kN/m以上であり、上限値は、適宜決定でき、例えば矢板の打ち込みに支障のない強度として、上限値が500kN/mである。また、使用材料の配合によっては、コンクリートと同程度の2000kN/mも可能である。これにより、脱水されない地盤中において、液状化せず、且つ打設後には掘削や矢板の打込みなどに支障のない適度な強度を発現することができる。 In the method for producing improved fluidized sand of the present invention, the improved fluidized sand obtained has a penetration stress of 50,000 Pa or less, preferably 30,000 Pa or less in a texture test within 1 hour after production. As a result, the improved fluidizing sand has sufficient fluidity at the time of casting even if it contains ground granulated blast furnace slag or the like. The unconfined compressive strength 28 days after production is 100 kN/m 2 or more , and the upper limit can be determined as appropriate. In addition, depending on the composition of the materials used, 2000 kN/m 2 , which is the same level as concrete, is possible. As a result, in the ground that is not dewatered, it does not liquefy, and after placement, it is possible to develop an appropriate strength that does not interfere with excavation or driving of sheet piles.

(流動化砂組成物)
本発明において、流動化砂組成物は、消石灰及び石膏から選択される1種又は2種、材料砂、含水比調製用水、流動化剤及び高炉スラグ微粉末を含有する。流動化砂組成物に含まれる材料砂、含水比調製用水、流動化剤、高炉スラグ微粉末、消石灰及び石膏は、前記混合材及び改良流動化砂の製造方法に記載したものと同様のものが使用できる。
(fluidized sand composition)
In the present invention, the fluidized sand composition contains one or two selected from slaked lime and gypsum, material sand, water for adjusting the water content, a fluidizing agent, and ground granulated blast furnace slag. The material sand, water for adjusting the water content, fluidizing agent, ground granulated blast furnace slag, hydrated lime and gypsum contained in the fluidized sand composition are the same as those described in the above-mentioned mixed material and method for producing improved fluidized sand. Available.

流動化砂組成物において、流動化剤の配合量は、材料砂100重量部に対し、0.01~2.0重量部である。流動化剤の配合量が少な過ぎると、材料砂が分離し圧送できない点で好ましくなく、多過ぎると、経済性の点で好ましくない。また、高炉スラグ微粉末の配合量は、乾燥状態の材料砂100重量部に対して、1~20重量部である。高炉スラグ微粉末の配合量が少な過ぎると、強度が発現しない点で好ましくなく、多過ぎると、圧送性が低下する点で好ましくない。消石灰又は石膏の配合量は、材料砂100重量部に対して、1~20重量部である。消石灰又は石膏の配合量が少な過ぎると、材料砂が分離し圧送できない点で好ましくなく、多過ぎると、経済性の点で好ましくない。 In the fluidized sand composition, the blending amount of the fluidizing agent is 0.01 to 2.0 parts by weight per 100 parts by weight of the material sand. If the blending amount of the fluidizing agent is too small, the material sand will be separated and cannot be pumped. Further, the blending amount of ground granulated blast furnace slag is 1 to 20 parts by weight with respect to 100 parts by weight of material sand in a dry state. If the amount of ground granulated blast furnace slag is too small, strength is not developed, and if it is too large, pumpability is lowered. The blending amount of slaked lime or gypsum is 1 to 20 parts by weight per 100 parts by weight of material sand. If the amount of slaked lime or gypsum is too small, the material sand will separate and cannot be pumped.

本発明において、流動化砂組成物は、改良流動化砂と同様の、製造後1時間以内のテクスチャー試験における貫入応力が、50,000Pa以下、好ましくは30,000Pa以下である。これにより、改良流動化砂は、高炉スラグ微粉末等が配合されていても、打設時には十分な流動性を有する。また、製造後28日の一軸圧縮強さは100kN/m以上であり、上限値は、適宜決定でき、例えば矢板の打ち込みに支障のない強度として、上限値が500kN/mである。これにより、脱水されない地盤中において、液状化せず、且つ打設後には掘削や矢板の打込みなどに支障のない適度な強度を発現することができる。 In the present invention, the fluidized sand composition has a penetration stress of 50,000 Pa or less, preferably 30,000 Pa or less in a texture test within 1 hour after production, like the improved fluidized sand. As a result, the improved fluidizing sand has sufficient fluidity at the time of casting even if it contains ground granulated blast furnace slag or the like. The unconfined compressive strength 28 days after production is 100 kN/m 2 or more , and the upper limit can be determined as appropriate. As a result, in the ground that is not dewatered, it does not liquefy, and after placement, it is possible to develop an appropriate strength that does not interfere with excavation or driving of sheet piles.

(流動化砂組成物の製造方法)
流動化組成物は、消石灰及び石膏から選択される1種又は2種、材料砂、含水比調製用水、流動化剤及び高炉スラグ微粉末を混合することで製造することができ、消石灰及び石膏から選択される1種又は2種、材料砂及び高炉スラグ微粉末を混合する第1工程と、該第1工程で得られた混合物と、含水比調製用水及び流動化剤を混合する第2工程とを行うことが好ましい。
(Method for producing fluidized sand composition)
The fluidizing composition can be produced by mixing one or two selected from slaked lime and gypsum, material sand, water for adjusting the water content, fluidizing agent and ground granulated blast furnace slag. A first step of mixing one or two selected materials, sand and ground granulated blast furnace slag, and a second step of mixing the mixture obtained in the first step with water for adjusting the water content and a fluidizing agent. It is preferable to

(流動化砂組成物製造プラント及び圧入式砂杭造成装置)
流動化砂組成物製造プラント及び圧入式砂杭造成装置を図1を参照して説明する。図1において、圧入式砂杭造成装置50は、流動化砂組成物製造プラント10と、砂杭造成用の中空管23と、流動化砂組成物製造プラント10で製造された流動化砂組成物を中空管23に送る圧送ポンプ4と、圧送ポンプ4と中空管23とを接続する流動化砂組成物供給配管36とを備える。なお、「消石灰及び石膏から選ばれる1種又は2種」は、装置説明においては「消石灰」と略称する。
(Fluidized sand composition manufacturing plant and press-fit sand pile construction device)
A fluidized sand composition manufacturing plant and a press-fit type sand pile forming apparatus will be described with reference to FIG. In FIG. 1, a press-fit type sand pile construction device 50 includes a fluidized sand composition manufacturing plant 10, a hollow pipe 23 for sand pile construction, and a fluidized sand composition manufactured in the fluidized sand composition manufacturing plant 10. A compressing pump 4 for sending the material to the hollow tube 23 and a fluidized sand composition supply pipe 36 connecting the compressing pump 4 and the hollow tube 23 are provided. "One or two selected from slaked lime and gypsum" is abbreviated as "slaked lime" in the description of the apparatus.

流動化砂組成物製造プラント10は、砂杭区域26より離れた場所にあるもので、流動化砂組成物を製造する装置群である。流動化砂組成物製造プラント10は、例えば流動化砂組成物混合撹拌手段1、材料砂供給手段2、高炉スラグ微粉末供給手段3、消石灰供給手段4、含水比調製用水供給手段5、流動化剤供給手段6、流動化砂組成物移送配管31、材料砂移送配管32、高炉スラグ微粉末移送配管33、消石灰移送配管34、含水比調製用水移送配管35、流動化剤移送配管36からなる。なお、それぞれの供給手段には、必要に応じて、貯留タンク、供給ポンプ及び撹拌手段など設置される。このような流動化砂組成物製造プラント10は、砂杭施工区域26に設置しなくてもよく、既設構造物の直下や直近に施工する際の設置スペースを確保する必要がない点で好適である。流動化砂組成物供給配管36は、通常可撓性ホースが使用され、その長さは適宜決定されるが、概ね200m未満である。なお、砂杭施工区域26は、本例では、コンクリート床板261とその下方地盤262との間に空洞部263が存在する地盤である。 The fluidized sand composition manufacturing plant 10 is located at a location remote from the sand piling area 26 and is a group of equipment for manufacturing a fluidized sand composition. The fluidized sand composition manufacturing plant 10 includes, for example, fluidized sand composition mixing and stirring means 1, material sand supply means 2, granulated blast furnace slag supply means 3, slaked lime supply means 4, water content adjustment water supply means 5, fluidization It consists of a fluidizing sand composition transfer pipe 31, a material sand transfer pipe 32, a granulated blast furnace slag powder transfer pipe 33, a hydrated lime transfer pipe 34, a water content adjustment water transfer pipe 35, and a fluidizing agent transfer pipe 36. In addition, a storage tank, a supply pump, an agitating means, and the like are installed in each supply means as required. Such a fluidized sand composition manufacturing plant 10 does not need to be installed in the sand pile construction area 26, and is suitable in that there is no need to secure an installation space when constructing directly under or in the immediate vicinity of an existing structure. be. A flexible hose is usually used for the fluidized sand composition supply pipe 36, and its length is determined appropriately, but is generally less than 200 m. In this example, the sand pile construction area 26 is ground in which a hollow portion 263 exists between a concrete floor plate 261 and a ground 262 below it.

圧送ポンプ4は、公知のものが使用でき、例えばピストンポンプ、スクイズポンプなどが挙げられる。また、圧送ポンプ4は、低圧ポンプでも高圧ポンプでもよいが、高圧ポンプを用いると、圧入砂杭造成工法が利用できる。 A known pressure-feeding pump 4 can be used, and examples thereof include a piston pump and a squeeze pump. Also, the pumping pump 4 may be either a low-pressure pump or a high-pressure pump, but if a high-pressure pump is used, a press-in sand pile construction method can be used.

次に、流動化砂組成物の製造方法の一例を示す。流動化砂組成物製造プラント10において、先ず、所定量の材料砂を材料砂供給手段2から流動化砂組成物混合撹拌手段1に供給する。次いで、所定量の高炉スラグ微粉末及び所定量の消石灰を、流動化砂組成物混合撹拌手段1中の材料砂に混合する。この粉末混合物を充分に撹拌混合する。材料砂、高炉スラグ微粉末及び消石灰は、粉末状であるため、均一に混合することができる。この粉末混合物に対して、含水比調整用水及び流動化剤を配合して、流動化砂組成物を得る。なお、流動化砂組成物には、別途、公知の遅効性塑性化剤を配合することもできる。 An example of a method for producing a fluidized sand composition will now be described. In the fluidized sand composition manufacturing plant 10 , first, a predetermined amount of material sand is supplied from the material sand supply means 2 to the fluidized sand composition mixing and stirring means 1 . Next, a predetermined amount of ground granulated blast furnace slag and a predetermined amount of slaked lime are mixed with the material sand in the fluidized sand composition mixing and stirring means 1 . The powder mixture is thoroughly stirred and mixed. Since the material sand, ground granulated blast furnace slag, and slaked lime are in the form of powder, they can be uniformly mixed. Water for adjusting the water content ratio and a fluidizing agent are blended with this powder mixture to obtain a fluidized sand composition. It should be noted that the fluidized sand composition may additionally contain a known delayed-acting plasticizer.

本発明の改良流動化砂及び流動化砂組成物(以下、単に「改良流動化砂」とも言う。)は、公知の砂杭造成工法により、地盤中に砂杭を造成することができる。すなわち、この砂杭の造成工法としては、静的締固め砂杭造成工法や打ち戻し式サンドコンパクション工法などの公知の締固め砂杭造成工法が挙げられる。また、圧入砂杭造成工法であれば、圧入時、塑性化した地盤改良材を地中に拡径の砂杭として造成し、これを繰り返して行えばよい。 The improved fluidized sand and fluidized sand composition of the present invention (hereinafter also simply referred to as "improved fluidized sand") can form sand piles in the ground by a known sand pile construction method. That is, examples of the construction method of this sand pile include known compaction sand pile construction methods such as a static compaction sand pile construction method and a hammering-type sand compaction construction method. In the case of the press-in sand pile construction method, the plasticized soil improvement material is formed into the ground as a sand pile with an expanded diameter at the time of press-in, and this may be repeated.

なお、圧入砂杭造成工法は、図1に示すように、中空管23を地盤中の設計深度まで貫入した後、中空管23を通して地表から地中に改良流動化砂を圧入し、必要に応じて圧入と同時に塑性化剤を添加して、地中に拡径の砂杭を造成し、これを繰り返して行うことにより、所定長の拡径の砂杭を造成する工法である。 In the press-in sand pile construction method, as shown in FIG. In this method, a plasticizing agent is added at the same time as press-fitting according to the condition, and a sand pile with an expanded diameter is formed in the ground.

地中に充填、又は圧入された砂杭材料は、含水比調製用水、流動化剤、高炉スラグ微粉末、及び消石灰又は石膏を含み、打設後、掘削や矢板の打込みなどに支障のない適度な強度を有する。本発明の改良流動化砂や流動化砂組成物が適用される地盤としては、矢板等の構築物が除去された後の改良を行わない空洞充填部、地盤中で脱水される地盤及び脱水されない地盤が挙げられる。空洞充填部に充填された改良流動化砂や流動化砂組成物は、充填後、空洞内に隙間を生じることなく、適度な強度を発現することができる。また、透水性の低い地盤で排水が望めないような地盤においては、自硬することで、適度な強度を付与することができる。従来の公知の流動化砂においては、このような地盤では排水できず、十分な強度が得られなかった。 The sand pile material filled or pressed into the ground contains water for adjusting the water content, fluidizing agent, ground granulated blast furnace slag, and slaked lime or gypsum. strength. The ground to which the improved fluidized sand or fluidized sand composition of the present invention is applied includes void-filling areas where structures such as sheet piles are removed and not improved, ground that is dewatered in the ground, and ground that is not dewatered. is mentioned. The improved fluidized sand and the fluidized sand composition filled in the cavity filling portion can develop appropriate strength without creating gaps in the cavity after filling. In addition, in a ground with low water permeability where drainage cannot be expected, self-hardening can impart appropriate strength. Conventionally known fluidized sand cannot be drained in such ground, and sufficient strength cannot be obtained.

次に、実施例を挙げて、本発明を更に具体的に説明する。
(実施例1)
(混合材A1の製造)
混合撹拌機に、高炉スラグ微粉末(比表面積4000cm/g)と消石灰を入れ、両者が均一に混ざるまで撹拌し、粉末状の混合材A1を製造した。なお、消石灰の配合量は、高炉スラグ微粉末100重量部に対して、50重量部であった。この配合は、高炉スラグ微粉末の配合量が、消石灰100重量部に対して、200重量部となる。
EXAMPLES Next, the present invention will be described in more detail with reference to examples.
(Example 1)
(Manufacture of mixed material A1)
Ground granulated blast furnace slag (specific surface area: 4000 cm 2 /g) and slaked lime were placed in a mixing stirrer and stirred until they were uniformly mixed to produce a powdered mixed material A1. The amount of slaked lime mixed was 50 parts by weight with respect to 100 parts by weight of ground granulated blast furnace slag. In this formulation, the blending amount of ground granulated blast furnace slag is 200 parts by weight with respect to 100 parts by weight of slaked lime.

(改良流動化砂B1の製造)
予め公知の流動化砂1を準備した。この流動化砂1は、含水比35.0重量%の蓋井砂(材料砂)に、流動化剤(ポイリアクリルアミド)を含むものであった。流動化剤の配合量は、蓋井砂100重量部に対して、0.64重量部であった。次に、流動化砂1の100重量部に対して、2.21重量部の混合材A1を添加し、撹拌混合して、改良流動化砂B1を製造した。改良流動化砂B1中、高炉スラグ微粉末の配合量は、材料砂100重量部に対して2重量部であった。
(Production of improved fluidized sand B1)
A known fluidized sand 1 was prepared in advance. The fluidized sand 1 was futai sand (material sand) with a water content of 35.0% by weight and a fluidizing agent (polyacrylamide). The blending amount of the fluidizing agent was 0.64 parts by weight with respect to 100 parts by weight of the futa well sand. Next, 2.21 parts by weight of mixture material A1 was added to 100 parts by weight of fluidized sand 1, and mixed by stirring to produce improved fluidized sand B1. In the improved fluidized sand B1, the blending amount of ground granulated blast furnace slag was 2 parts by weight with respect to 100 parts by weight of the material sand.

(テクスチャー試験)
市販のテクスチャー試験装置(山電社製;卓上式物性測定器)を使用し、所定容器に試料(改良流動化砂B1)を充填し、試験装置にセットした後、シリンダーを一定速度で上下させ、試料上面から20mmの貫入及び引抜を行い、貫入時の最大荷重Paを応力に換算して貫入応力値として求めた。試験は、改良流動化砂1製造直後(経過0時間)、製造後48時間(2日後)、製造後72時間(3日後)、製造後168時間(7日後)、製造後672時間(28日後)について行った。その結果を表1に示す。
(texture test)
Using a commercially available texture testing device (manufactured by Yamaden Co., Ltd.; tabletop physical property measuring device), fill a predetermined container with the sample (improved fluidized sand B1), set it in the testing device, and then move the cylinder up and down at a constant speed. , the sample was penetrated and pulled out 20 mm from the upper surface of the sample, and the maximum load Pa at the time of penetration was converted into stress to obtain a penetration stress value. The test was performed immediately after production (0 hours after production), 48 hours (2 days after production), 72 hours (3 days after production), 168 hours (7 days after production), and 672 hours (28 days after production). ) followed. Table 1 shows the results.

(実施例2)
(混合材A2の製造)
混合撹拌機に、高炉スラグ微粉末(比表面積4000cm/g)と石膏を入れ、両者が均一に混ざるまで撹拌し、粉末状の混合材A2を製造した。なお、石膏の配合量は、高炉スラグ微粉末100重量部に対して、50重量部であった。
(Example 2)
(Manufacture of mixed material A2)
Ground granulated blast furnace slag (specific surface area: 4000 cm 2 /g) and gypsum were put into a mixing stirrer and stirred until they were uniformly mixed to produce a powdered mixed material A2. The amount of gypsum compounded was 50 parts by weight with respect to 100 parts by weight of ground granulated blast furnace slag.

(改良流動化砂B2の製造)
混合材A1に代えて、混合材A2とした以外は、実施例1の(改良流動化砂B1の製造)と同様の方法により、改良流動化砂B2を製造し、テクスチャー試験を実施した。その結果を表1に示す。
(Production of improved fluidized sand B2)
Improved fluidized sand B2 was produced in the same manner as in Example 1 (production of improved fluidized sand B1) except that mixed material A2 was used instead of mixed material A1, and a texture test was conducted. Table 1 shows the results.

(比較例1)
(流動化砂b1の製造)
混合材1の添加を省略した以外は、実施例1の(改良流動化砂B1の製造)と同様の方法により、流動化砂b1を調製し、テクスチャー試験を実施した。すなわち、この比較例1の流動化砂b1は、公知の流動化砂そのものである。その結果を表1に示した。
(Comparative example 1)
(Production of fluidized sand b1)
Fluidized sand b1 was prepared in the same manner as in Example 1 (production of improved fluidized sand B1) except that addition of Mixture 1 was omitted, and a texture test was conducted. That is, the fluidized sand b1 of Comparative Example 1 is the known fluidized sand itself. The results are shown in Table 1.

(比較例2)
(流動化砂b2の製造)
混合材A1に代えて、高炉スラグ微粉末とした以外は、実施例1の(改良流動化砂B1の製造)と同様の方法により、流動化砂b2を製造し、テクスチャー試験を実施した。すなわち、この比較例2の流動化砂b2は、公知の流動化砂に高炉スラグ微粉末を添加したものである。その結果を表1に示した。
(Comparative example 2)
(Production of fluidized sand b2)
A fluidized sand b2 was produced in the same manner as in Example 1 (production of improved fluidized sand B1) except that ground granulated blast furnace slag was used instead of the mixed material A1, and a texture test was conducted. That is, the fluidized sand b2 of Comparative Example 2 is obtained by adding ground granulated blast furnace slag to known fluidized sand. The results are shown in Table 1.

(比較例3)
(混合材a3の製造)
消石灰に代えて、ベントナイトとした以外は、実施例1の(混合材A1の製造)と同様の方法により、混合材a3を製造した。すなわち、混合材a3は、高炉スラグ微粉末とベントナイトの混合物である。なお、ベントナイトの配合量は、高炉スラグ微粉末100重量部に対して、50重量部であった。
(Comparative Example 3)
(Production of mixed material a3)
A mixed material a3 was produced in the same manner as in Example 1 (production of mixed material A1) except that bentonite was used instead of slaked lime. That is, the mixed material a3 is a mixture of ground granulated blast furnace slag and bentonite. The amount of bentonite compounded was 50 parts by weight with respect to 100 parts by weight of ground granulated blast furnace slag.

(流動化砂b3の製造)
混合材A1に代えて、混合材a3とした以外は、実施例1の(改良流動化砂B1の製造)と同様の方法により、流動化砂b3を製造し、テクスチャー試験を実施した。すなわち、この比較例3の流動化砂b3は、公知の流動化砂に高炉スラグ微粉末とベントナイトの混合物を添加したものである。その結果を表1に示した。
(Production of fluidized sand b3)
Fluidized sand b3 was produced in the same manner as in Example 1 (Production of improved fluidized sand B1) except that mixed material a3 was used instead of mixed material A1, and a texture test was conducted. That is, the fluidized sand b3 of Comparative Example 3 is obtained by adding a mixture of ground granulated blast furnace slag and bentonite to known fluidized sand. The results are shown in Table 1.

(比較例4)
(流動化砂b4の製造)
混合材A1に代えて、固化セメントとした以外は、実施例1の(改良流動化砂B1の製造)と同様の方法により、流動化砂b4を製造し、テクスチャー試験を実施した。すなわち、この比較例4の流動化砂b4は、公知の流動化砂に固化セメントを添加したものである。固化セメントの配合量は、蓋井砂100重量部に対して、3重量部であった。その結果を表1に示した。
(Comparative Example 4)
(Production of fluidized sand b4)
Fluidized sand b4 was produced in the same manner as in Example 1 (Production of improved fluidized sand B1) except that solidified cement was used instead of mixed material A1, and a texture test was conducted. That is, the fluidized sand b4 of Comparative Example 4 is obtained by adding hardened cement to a known fluidized sand. The blending amount of the solidified cement was 3 parts by weight with respect to 100 parts by weight of the futa well sand. The results are shown in Table 1.

Figure 0007231513000001
Figure 0007231513000001

表1において、高炉スラグ微粉末単体(比較例2)は、無添加(比較例1)と同程度の貫入応力であり、固結による強度増加はみられなかった。一方、消石灰又は石膏を添加した実施例では大きな強度増加がみられた。また、ベントナイトの添加(比較例3)は、製造直後の貫入応力が高く、その値が大きく変化しなかった。このことから、ベントナイトのような細粒分は、強度に寄与しないことが判った。消石灰又は石膏を高炉スラグ微粉末に添加した実施例は、比較的貫入応力が高く、目標となる強度を発現した。消石灰(実施例1)と石膏(実施例2)を比較すると、消石灰の方が大きな貫入応力となっている。 In Table 1, the granulated blast furnace slag powder alone (Comparative Example 2) had a penetration stress comparable to that of no additive (Comparative Example 1), and no increase in strength due to caking was observed. On the other hand, in the examples in which slaked lime or gypsum was added, a large increase in strength was observed. Moreover, the addition of bentonite (Comparative Example 3) had a high penetration stress immediately after production, and the value did not change significantly. From this, it was found that fine grain fractions such as bentonite do not contribute to the strength. Examples in which slaked lime or gypsum was added to ground granulated blast furnace slag had relatively high penetration stress and exhibited the target strength. Comparing slaked lime (Example 1) and gypsum (Example 2), slaked lime has a larger penetration stress.

次に、混合材A1を構成する高炉スラグ微粉末と消石灰の混合系において、消石灰の配合量を一定とし、高炉スラグ微粉末の配合量が、貫入応力に及ぼす影響について検討した。以下、実施例3~5に示す。 Next, in the mixed system of the ground granulated blast furnace slag and slaked lime constituting the mixture material A1, the blending amount of slaked lime was kept constant, and the influence of the blending amount of the ground blast furnace slag on the penetration stress was studied. Examples 3 to 5 are shown below.

(実施例3~5)
(改良流動化砂B3~B5の製造)
高炉スラグ微粉末の配合量2重量部に代えて、4重量部(実施例3)、6重量部(実施例4)、8重量部(実施例5)とした以外は、実施例1の(改良流動化砂B1の製造)と同様の方法により、改良流動化砂B3~B5を製造し、テクスチャー試験を実施した。その結果を表2に示す。
(Examples 3-5)
(Production of improved fluidized sand B3-B5)
Instead of 2 parts by weight of ground blast furnace slag powder, 4 parts by weight (Example 3), 6 parts by weight (Example 4), and 8 parts by weight (Example 5) were used, except that ( Improved fluidized sands B3 to B5 were produced in the same manner as in (Production of improved fluidized sand B1), and texture tests were conducted. Table 2 shows the results.

Figure 0007231513000002
Figure 0007231513000002

表2の結果から、実施例1に比べ、高炉スラグ微粉末添加量が多い実施例3~5はいずれも貫入応力が大きくなっており、より固結していた。しかし、実施例3~5間では大きな違いはみられない。これは、高炉スラグ微粉末の添加量に対して、消石灰の添加量が不足しており、高炉スラグ微粉末の反応が促進されていないことが判る。 From the results in Table 2, in comparison with Example 1, Examples 3 to 5, in which the amount of ground granulated blast furnace slag added was large, had a larger penetration stress and were more solidified. However, there is no significant difference between Examples 3-5. This indicates that the amount of slaked lime added is insufficient with respect to the amount of ground granulated blast furnace slag, and the reaction of the ground granulated blast furnace slag is not promoted.

(実施例6)
(流動化砂組成物Cの製造)
前述の改良流動化砂と同じ組成となる流動化砂組成物Cを製造した。すなわち、蓋井砂、流動化剤(ポリアクリルアミド)、高炉スラグ微粉末(比表面積4000cm/g)、消石灰及び水を混合して、流動化砂組成物を製造した。具体的には、蓋井砂に、所定量の高炉スラグ微粉末と消石灰を添加し、均一になるまで混合攪拌し、次いで、この混合物に、所定量の水及び流動化剤を配合し、流動化砂組成物Cを製造し、テクスチャー試験を実施した。その結果、改良流動化砂Bと同じ結果を得た。
(Example 6)
(Production of fluidized sand composition C)
A fluidized sand composition C was prepared having the same composition as the improved fluidized sand described above. That is, Futai sand, fluidizing agent (polyacrylamide), ground granulated blast furnace slag (specific surface area: 4000 cm 2 /g), slaked lime and water were mixed to produce a fluidized sand composition. Specifically, a predetermined amount of ground granulated blast furnace slag and slaked lime are added to Futai sand, and the mixture is mixed and stirred until uniform. A chemical sand composition C was produced and a texture test was carried out. As a result, the same results as those of improved fluidized sand B were obtained.

(実施例7)
(混合材A2の製造)
消石灰の配合量50重量部に代えて、20重量部とした以外は、実施例1の(混合材A1の製造)と同様の方法により、混合材A2を作製した。なお、混合材A2において、高炉スラグ微粉末の配合量は、消石灰100重量部に対して、500重量部であった。
(Example 7)
(Manufacture of mixed material A2)
A mixed material A2 was produced in the same manner as in Example 1 (production of mixed material A1), except that the amount of slaked lime was changed to 20 parts by weight instead of 50 parts by weight. In the mixed material A2, the blending amount of ground granulated blast furnace slag was 500 parts by weight with respect to 100 parts by weight of slaked lime.

(改良流動化砂B6の製造)
混合材A1に代えて、混合材A2とした以外は、実施例1の(改良流動化砂B1の製造)と同様の方法により、改良流動化砂B6を作製し、製造後672時間(28日後)の試料に対して、一軸圧縮強度(JIS A1216)を測定した。その結果、173kN/mであった。
(Production of improved fluidized sand B6)
Improved fluidized sand B6 was prepared in the same manner as in Example 1 (production of improved fluidized sand B1) except that mixed material A2 was used instead of mixed material A1. ) was measured for unconfined compressive strength (JIS A1216). As a result, it was 173 kN/m 2 .

実施例7は、製造28日後は、掘削や矢板の打込みなどに支障のない適度な強度を有するものであった。従って、実施例7の改良流動化砂は、透水性の低い、圧入後は排水が望めないような地盤においても適用できる。 In Example 7, 28 days after production, it had an appropriate strength that does not interfere with excavation or driving of sheet piles. Therefore, the improved fluidized sand of Example 7 can also be applied to ground that has low water permeability and cannot be expected to drain after injection.

本発明によれば、打設時には十分な流動性を有し、脱水できる土壌又は脱水できない土壌中において、打設後、目的に応じた任意の強度を発現できる、又は周辺の硬質地盤と同等の強度を有する流動化砂組成物を提供できる。 According to the present invention, it has sufficient fluidity at the time of placing, and can express any strength according to the purpose after placing in soil that can be dehydrated or in soil that cannot be dehydrated, or can be equivalent to the surrounding hard ground. A fluidized sand composition having strength can be provided.

Claims (3)

地盤の空洞部に充填されるものであり、充填後、適宜な強度を発現する流動化砂組成物であって、
該流動化砂組成物は、消石灰及び石膏から選択される1種又は2種、材料砂、含水比調製用水、流動化剤及び高炉スラグ微粉末を含有するものであり、
該消石灰及び/又は石膏の配合量は、該高炉スラグ微粉末100重量部に対して、10~200重量部であり、
該空洞部への充填後における製造後28日の一軸圧縮強度が100~500kN/m であることを特徴とする流動化砂組成物。
A fluidized sand composition that is to be filled into a hollow part of the ground and exhibits appropriate strength after being filled,
The fluidized sand composition contains one or two selected from slaked lime and gypsum, material sand, water for adjusting the water content ratio, a fluidizing agent, and ground granulated blast furnace slag.
The blending amount of the slaked lime and/or gypsum is 10 to 200 parts by weight with respect to 100 parts by weight of the ground granulated blast furnace slag,
A fluidized sand composition characterized by having a uniaxial compressive strength of 100 to 500 kN/m 2 after 28 days after production after being filled into the cavity .
該流動化砂組成物中の材料砂100重量部に対して、高炉スラグ微粉末を1~20重量部、配合することを特徴とする請求項記載の流動化砂組成物。 2. The fluidized sand composition according to claim 1 , wherein 1 to 20 parts by weight of ground granulated blast furnace slag is blended with 100 parts by weight of the material sand in said fluidized sand composition. 該流動化砂組成物は、製造後1時間以内でのテクスチャー試験における貫入応力が、50,000Pa以下であることを特徴とする請求項又は記載の流動化砂組成物。 3. The fluidized sand composition according to claim 1 , wherein the fluidized sand composition has a penetration stress of 50,000 Pa or less in a texture test within one hour after production.
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JP2008308612A (en) 2007-06-15 2008-12-25 Ube Ind Ltd Slag-based grouting material and grouting method using the same
JP2011111766A (en) 2009-11-25 2011-06-09 Fudo Tetra Corp Method and apparatus for constructing slag pile
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JP2006182822A (en) 2004-12-27 2006-07-13 Denki Kagaku Kogyo Kk Highly penetrative grouting material
JP2008308612A (en) 2007-06-15 2008-12-25 Ube Ind Ltd Slag-based grouting material and grouting method using the same
JP2011111766A (en) 2009-11-25 2011-06-09 Fudo Tetra Corp Method and apparatus for constructing slag pile
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