JP5442944B2 - Injection material and injection method - Google Patents

Description

  The present invention relates to a ground injection material used in tunnel construction, ground improvement construction and water stop construction in various civil engineering works.

  Conventionally, in order to obtain ground reinforcement and water-stopping effect with cement-injection method, injection material mainly composed of fine powder slag or injection material using rapid hardening material including cement and calcium aluminate has been used. (See Patent Documents 1, 2, 3, and 4).

  However, the injecting material using fine powder slag has a very slow setting, and the infused milk may flow into the ground water or flow away from a predetermined pouring position.

  The injection material using calcium aluminate kneads cement milk and quick-hardening material slurry separately and mixes them just before injection, so two mixers and two pumps are required, and there is a problem that workability is complicated. It was. When cement and a rapid hardening material are mixed and kneaded at the same time to simplify the workability, it is difficult to control the setting time, and there is a possibility that a trouble that hardens the mixer and the pump may occur. When the ground is fine sand, silt, or clay, the permeability is small, and there is a possibility that it cannot be injected.

  In addition, during the injection, the amount of water may be increased for the purpose of improving pumpability and increasing the permeability into the ground. As a result, there is a risk that curing will be delayed and the strength may be lowered.

  An injection material containing fine particle cement, fine particle slag, calcium aluminosilicate, gypsum, a setting modifier, and a water reducing agent has been proposed (see Patent Document 5). However, the usage-amount of a water reducing agent is 0.01-10 mass parts with respect to 100 mass parts of cement, and differs from the usage-amount of this invention.

JP-A-6-33057 Japanese Patent Publication No.57-10058 Japanese Patent Application Laid-Open No. 2004-149685 JP 2006-016543 A JP 2002-88364 A

  As a result of various studies to solve the above-mentioned problems, the present inventor used a specific material, so that conventionally problematic cement and quick-hardening material were simultaneously kneaded, that is, injection by a one-shot method. The inventor has obtained the knowledge that it is possible to complete the present invention.

That is, the present invention is an injection material for a one-shot method comprising cement, blast furnace slag, calcium aluminosilicate glass, gypsum, a setting modifier, and a water reducing agent in the following proportions:
(1) The ratio of cement to blast furnace slag is 3 to 30 parts by mass of cement: blast furnace slag 97 to 70
Part (2) The amount of gypsum used is 50 to 100 parts by mass of calcium aluminosilicate glass.
200 parts by mass (3) The total proportion of cement and blast furnace slag and the total of calcium aluminosilicate glass and gypsum is 90 to 99 parts by mass of cement and blast furnace slag: 10 to 1 parts by mass of calcium aluminosilicate glass and gypsum (4) 100 parts by mass of organic acid and 50 carbonates
The amount of the setting regulator comprising ~ 1000 parts by mass is 0.05 to 2 parts by mass (5) of the water reducing agent with respect to 100 parts by mass in total of cement, blast furnace slag, calcium aluminosilicate glass, and gypsum. The amount used is 12-30 parts by mass with respect to 100 parts by mass of cement.
Water reducing agent is the one-shot method for injecting material is a melamine sulfonic acid formalin condensate salt, an the one-shot method for injecting material average particle diameter of 10μm or less, cement, blast furnace slag, calcium aluminosilicate glass , Gypsum, setting agent, water reducing agent,
And a one-shot injection method in which water is premixed and injected at the following ratio:
(1) The ratio of cement to blast furnace slag is 3 to 30 parts by mass of cement: blast furnace slag 97 to 70
Part (2) The amount of gypsum used is 50 to 100 parts by mass of calcium aluminosilicate glass.
200 parts by mass (3) The total proportion of cement and blast furnace slag and the total of calcium aluminosilicate glass and gypsum is 90 to 99 parts by mass of cement and blast furnace slag: 10 to 1 parts by mass of calcium aluminosilicate glass and gypsum (4) 100 parts by mass of organic acid and 50 carbonates
The amount of the setting regulator comprising ~ 1000 parts by mass is 0.05 to 2 parts by mass (5) of the water reducing agent with respect to 100 parts by mass in total of cement, blast furnace slag, calcium aluminosilicate glass, and gypsum. The amount used is 12 to 30 parts by mass with respect to 100 parts by mass of cement. (6) The amount of water used is 100 to 1000 parts by mass with respect to a total of 100 parts by mass of cement, blast furnace slag, calcium aluminosilicate glass, and gypsum.
Water reducing agent is the one shot method grouting melamine sulfonic acid formalin condensate salt, an average particle size of the one-shot method grouting is 10μm or less.

  By using the cement composition for injection of the present invention, an effect that injection by one shot is possible is obtained.

  Hereinafter, the present invention will be described in detail.

  The cement used in the present invention is obtained by pulverizing or classifying various Portland cements such as normal strength, early strength, and ultra-early strength, preferably into ultrafine cement having an average particle size of 20 μm or less. More preferably, it is 10 micrometers or less, Most preferably, it is 7 micrometers or less. If it exceeds 20 μm, the permeability at the time of injection may be lowered and the initial strength development may not be sufficiently improved.

  The blast furnace slag used in the present invention is obtained by quenching molten slag discharged from the blast furnace in the process of steel production with water or the like into glass, pulverizing it into fine powder, and having latent hydraulic properties. It has the property of being cured by the stimulating action of alkali. Other than this, for example, slag obtained by melting municipal waste or sewage sludge, dephosphorization slag, slow-cooled slag, and the like can be used.

The composition of blast furnace slag, CaO content of 35 to 50% _Al 2 _{O 3} content of 10% to 25%, and SiO ₂ content of 31 to 40% are preferred, CaO content of 40 to 50% _Al 2 _{O 3} containing A rate of 11 to 20% and a SiO ₂ content of 35 to 39% are more preferable. The blast furnace slag contains impurities such as MgO, TiO ₂ , Fe ₂ O ₃ , Na ₂ O, and K ₂ O, but is acceptable as long as the effects of the present invention are not impaired.

  By containing blast furnace slag, high injectability and long-term strength are imparted. The fineness of the blast furnace slag is preferably an average particle size of 10 μm or less, more preferably 7 μm or less. If it exceeds 10 μm, in addition to the decrease in permeability during injection, there may be cases where the improvement in short- and long-term strength development is not sufficiently exhibited.

  The ratio of cement to blast furnace slag is preferably 3 to 30 parts by mass of cement: 97 to 70 parts by mass of blast furnace slag, and more preferably 95 to 75 parts by mass of cement 5 to 25: blast furnace slag. If the amount of cement used is less than 3 parts by mass, the short-term strength may be small. If it exceeds 30 parts by mass, the viscosity when the injection material is used as a suspension may increase, and the permeability may decrease.

  Calcium aluminosilicate (hereinafter referred to as CAS) used in the present invention is obtained by heating and melting a calcia raw material, an alumina raw material, and a silica raw material in an electric furnace, a high-frequency furnace, or the like. It contributes to.

The composition of CAS is preferably CaO content 20 to 60%, Al ₂ O ₃ content 20 to 70%, and SiO ₂ content 5 to 30%, CaO content 30 to 55%, Al ₂ O ₃ content. 30% to 60%, and SiO ₂ content of 10-20% is more preferable. Outside this range, the short-term strength may be small.

  CAS is a mixture of calcia raw materials such as limestone, alumina raw materials such as alumina, bauxite, feldspar, and clay, and silica raw materials such as quartzite, quartz sand, quartz, and diatomaceous earth at a predetermined ratio. Manufactured by firing in a rotary kiln or the like, or melting in an electric furnace or high-frequency furnace.

As CAS, crystalline compounds such as 2CaO · Al ₂ O ₃ · SiO ₂ and CaO · Al ₂ O ₃ · 2SiO ₂ can be used, but the melt is rapidly cooled because of its high short-term strength. The glassy thing obtained by these is preferable.

The vitrification rate of CAS is as follows: CAS is heated at 1,000 ° C. for 2 hours, then slowly cooled at a cooling rate of 5 ° C./minute, and the area S ₀ of the main peak of the crystalline mineral is determined by powder X-ray diffraction method. From the main peak S of the crystal, X (%) = 100 × (1−S / S ₀ ). The vitrification rate of CAS is preferably 50% or more, more preferably 80% or more, and most preferably 90% or more in terms of short-term strength. If it is less than 50%, the short-term strength may be small.

  The fineness of CAS is preferably 10 μm or less, more preferably 7 μm or less, with an average particle size of 10 μm or less. If it exceeds 10 μm, the permeability at the time of injection may be reduced, and the improvement in short-term strength development may be poor.

  Examples of the gypsum used in the present invention include anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum. Furthermore, natural gypsum, chemical gypsum such as phosphoric acid byproduct gypsum, waste gypsum, and hydrofluoric acid byproduct gypsum, or gypsum obtained by heat-treating these can be mentioned. Among these, anhydrous gypsum is preferable in terms of high strength development.

  The fineness of gypsum has an average particle size of 10 μm or less, preferably 7 μm or less. If it exceeds 10 μm, the permeability during injection may decrease.

  The amount of gypsum used is preferably 50 to 200 parts by mass and more preferably 70 to 150 parts by mass with respect to 100 parts by mass of CAS. If it is less than 50 parts by mass, the short-term strength may be small, and if it exceeds 200 parts, the permeability may decrease.

  The ratio of the sum of cement and blast furnace slag and the sum of CAS and gypsum (hereinafter referred to as “quick hardwood”) is preferably 90 to 99 parts by mass of cement and blast furnace slag: 10 to 1 parts by mass of calcium aluminosilicate glass and gypsum. The total of cement and blast furnace slag is 97 to 92 parts by mass: The total of 3 to 8 parts by mass of calcium aluminosilicate glass and gypsum is more preferable. If the total amount of calcium aluminosilicate glass and gypsum is less than 1 part by mass, the expression of short-term strength may be poor. If the total amount of calcium aluminosilicate glass and gypsum exceeds 10 parts by mass, it is difficult to control the setting time, and a mixer or pump May harden and deteriorate the permeability.

  In the present invention, a setting modifier is used so that a required curing time can be obtained.

  As the setting regulator used in the present invention, aluminate such as sodium aluminate and potassium aluminate, carbonate such as sodium carbonate and potassium carbonate, hydroxide such as sodium hydroxide and potassium hydroxide, aluminum sulfate, Sulfates such as iron sulfate and alum, silicates such as sodium silicate and potassium silicate, phosphates such as sodium phosphate, calcium phosphate and magnesium phosphate, and lithium borate and sodium borate Examples thereof include inorganic salts such as borates, citric acid, gluconic acid, tartaric acid, malic acid or organic acids such as sodium salts, potassium salts and calcium salts thereof, and sugars. More than one species can be used in combination. Among these, it is preferable to use a carbonate and an organic acid in combination in order to secure a required curing time. As the salt, sodium salt and potassium salt are preferable.

  When carbonate and an organic acid are used in combination, the amount of carbonate used is preferably 50 to 1000 parts by mass, more preferably 100 to 500 parts by mass with respect to 100 parts by mass of the organic acid. If the amount is less than 50 parts by mass, the short-term strength may be poorly expressed, and if it exceeds 1000 parts, it may be difficult to obtain a predetermined delay.

  Although the usage-amount of a setting regulator is not specifically limited in order to adjust according to hardening time, 0.05-2 mass parts is preferable with respect to a total of 100 mass parts of cement, a blast furnace slag, and a quick-hardening material. 0.1 to 1 part by mass is more preferable. If it is less than 0.05 parts by mass, it may be difficult to ensure the curing time, and if it exceeds 2 parts by mass, the curing time may become abnormally long, resulting in a non-uniform solidified state.

  The maximum particle size of the injection material in the present invention is preferably 20 μm or less, more preferably 10 μm or less, and most preferably 7 μm or less. If it exceeds 20 μm, injection into fine gaps may be difficult depending on the geology of the ground.

  The method for preparing the particle size of the injection material is not particularly limited, but each material is separately pulverized by a pulverizer such as a ball mill, and those having a size of 20 μm or less are collected by classification, and then mixed. Any method can be used in which each material is mixed and then pulverized and collected by classification to collect materials of 20 μm or less. However, when the materials are mixed and then pulverized and classified, the mixing ratio may change due to the difference in density of the materials. The method for adjusting the particle size of the injection material is preferably a method in which each material is separately pulverized, classified, and then mixed.

  A water reducing agent is used to improve the permeability into the ground.

  Water reducing agents used in the present invention include naphthalenesulfonic acid formalin condensate salt-based, lignin sulfonate-based, melamine sulfonic acid formalin condensate-based salt, polycarboxylate-based, and polyether-based high-performance water reducing agents. Is mentioned. Among these, a melamine sulfonic acid formalin condensate salt system is preferable in that the viscosity of the suspension of the injection material is small.

  The amount of the water reducing agent used is preferably 12 to 30 parts by mass or less, more preferably 14 to 20 parts by mass based on 100 parts by mass of cement. If it is less than 12 parts by mass, the permeability may be deteriorated in the case of a low water ratio, and if it exceeds 30 parts, the viscosity of the suspension of the injection material may be increased and the permeability may be deteriorated.

  The amount of water used when the injection material is used as a suspension is not particularly limited as long as it can be pumped by a pump, but is 100 to 1000 parts by mass with respect to a total of 100 parts by mass of cement, blast furnace slag and rapid hardening material. Is preferable, and 200-500 mass parts is more preferable. If the amount is less than 100 parts by mass, the viscosity of the suspension increases and the permeability may be reduced. If the amount exceeds 1000 parts by mass, the suspension may not be cured.

  The mixing method and the injection method of the injection material are not particularly limited. Depending on the type of injection pipe, it can be applied to currently used construction methods such as single pipe lot construction method, single pipe strainer construction method, double pipe single phase construction method, double pipe double phase construction method, double pipe double packer construction method.

  Depending on the method of injecting the suspension into the ground, it can be applied to the 1-shot system, 1.5-shot system, and 2-shot system. In the one-shot system, the main material consisting of cement and blast furnace slag and the hardened material are agitated and mixed in advance by a chemical mixer at a predetermined blending ratio, and the suspension in a single material state in which the main material and the hardened material are mixed is pumped Then, it is a method to inject into the ground. In the 1.5 shot system, the main material and the hardened material are individually pumped to the injection tube, the two materials are mixed at the head of the injection tube, and the mixed suspension is discharged from the tip of the injection tube. This is the method of injecting. The two-shot method is a method in which the main material and the quick-hardening material are individually sent to the injection tube by a pump and the two materials are mixed at the moment of being discharged from the tip of the injection tube, as in the 1.5-shot method. The present invention can be applied to the one-shot method because it can ensure the gelation time in one material state and does not harden the mixer or pump. In the case of the one-shot method, cement milk and quick-hardening material slurry are mixed in advance, so that only one mixer or pump is required and the workability is simple.

  Hereinafter, the present invention will be described in detail with reference to experimental examples.

Experimental example 1
Cement, blast furnace slag, CAS and gypsum were classified and pulverized. Then, 95 parts by mass of the main material consisting of 20 parts by mass of cement and 80 parts by mass of blast furnace slag, 5 parts by mass of hardened material consisting of 100 parts by mass of CAS and 100 parts by mass of gypsum were mixed, and the average particle diameter injection shown in Table 1 was performed. A material was prepared. A suspension was prepared by mixing 0.7 parts by mass of a setting modifier and 400 parts by mass of water with 100 parts by mass of the injection material and 16 parts by mass of a water reducing agent with respect to 100 parts by mass of cement.
After the suspension was prepared, the penetration length was measured using a simulated sand layer. The results are shown in Table 1.

<Materials used>
Cement: Ordinary Portland cement-classified blast furnace slag: Fine granulated blast furnace slag with a composition of CaO 42%, Al ₂ O ₃ 13%, SiO ₂ 34%, and other 11% CAS: CaO 45%, Al ₂ O ₃ 40% , And SiO _{2 of} 15% composition, vitrification rate 95%
Gypsum: Natural anhydrous gypsum finely pulverized water reducing agent: Melamine sulfonic acid formalin condensate salt system, powdery coagulation regulator: Mixture consisting of 100 parts by mass of citric acid and 300 parts by mass of potassium carbonate Sand: Toyoura sand (former Toyoura standard sand)
Water: tap water

<Measurement method>
Average particle diameter: The average particle diameter is measured by a laser diffraction method. The model used was LA-920 (Horiba Seisakusho).
Penetration length: A civil engineering society standard vinyl bag with a diameter of 5 cm was filled with Toyoura cinnabar so as to be 20 cm, and 200 ml of the prepared suspension was poured gently from the upper surface to allow natural penetration. After 2 hours, the penetration length into the simulated sand layer was measured.
Time to 20 cm: In the measurement of the penetration length, the time from the injection of the suspension into the upper surface until the suspension penetrates into the simulated sand layer 20 cm was measured.

  From Table 1, it was found that the smaller the average particle diameter of the injection material, the higher the permeability.

Experimental example 2
A suspension was prepared and tested in the same manner as in Experimental Example 1 except that a main material composed of cement and blast furnace slag shown in Table 2 was used and an injection material having an average particle diameter of 5 μm was prepared. The results are shown in Table 2.

<Measurement method>
Gelation time: The time from when the suspension is put into the cup until the suspension stops flowing even if the cup containing the suspension is tilted.
Curing time: The time from the penetration of the suspension into the sand until the touch of the vinyl bag and the suspension that has penetrated the sand does not dent in the penetration length measurement.
Short-term strength: Measures compressive strength 24 hours after curing in measurement of curing time. The specimen size is 4 × 4 × 16 cm. The measurement of compressive strength conformed to JIS R 5201.

  From Table 2, it was found that when the ratio of cement and blast furnace slag is appropriate, high permeability and short-term strength development can be obtained. It was found that the gelation time in one material state can be ensured, so that it can have a certain working time and harden quickly after penetration.

Experimental example 3
Except for using a hard part consisting of 100 parts by weight of CAS and 100 parts by weight of gypsum, using the parts by weight shown in Table 3 in a total of 100 parts by weight of the main material and the quick hard part, and producing an injection material having an average particle diameter of 5 μm A suspension was prepared in the same manner as in Experimental Example 1, and the test was performed. The results are shown in Table 3.

  From Table 3, it was found that high penetration and short-term strength development can be obtained when an appropriate amount of rapid hardening material is used. It was found that the gelation time in one material state can be ensured, so that it can have a certain working time and harden quickly after penetration.

Experimental Example 4
A suspension was prepared in the same manner as in Experimental Example 1, except that the setting modifier shown in Table 4 was used for a total of 100 parts by mass of the main material and the hardened material, and an injection material having an average particle diameter of 5 μm was prepared. The test was conducted. The results are shown in Table 4.

  From Table 4, it was found that high penetrability can be obtained when the setting modifier is in an appropriate amount. It was found that the gelation time in one material state can be ensured, so that it can have a certain working time and harden quickly after penetration.

Experimental Example 5
A suspension was prepared and tested in the same manner as in Experimental Example 1 except that a rapid hardening material composed of 100 parts by mass of CAS and gypsum shown in Table 5 was used and an injection material having an average particle diameter of 5 μm was prepared. The results are shown in Table 5.

  From Table 5, it was found that when the amount of gypsum is appropriate, high permeability and short-term strength development can be obtained.

Experimental Example 6
A suspension was prepared and tested in the same manner as in Experimental Example 1 except that the water reducing agent shown in Table 6 was used with respect to 100 parts by mass of cement and an injection material having an average particle diameter of 5 μm was prepared. The results are shown in Table 6.

  From Table 6, it was found that when the water reducing agent is in an appropriate amount, high permeability can be obtained. It was found that the gelation time in one material state can be ensured, so that it can have a certain working time and harden quickly after penetration.

Experimental Example 7
A suspension was prepared in the same manner as in Experimental Example 1 except that 100 parts by mass of citric acid and a setting regulator composed of potassium carbonate shown in Table 7 were used, and an injection material having an average particle diameter of 5 μm was prepared. Carried out. The results are shown in Table 7.

  From Table 7, it was found that when the hardened material is in an appropriate amount, high short-term strength development can be obtained. It was found that the gelation time in one material state can be ensured, so that it can have a certain working time and harden quickly after penetration.

  Since the injection material of the present invention can secure a gelation time in a single material state, it is possible to simultaneously knead cement and a rapid hardening material, that is, injection by a one-shot method. Even when the gelation time of one material state is ensured, it cures quickly after permeation and high strength developability is obtained.

  When this injection material is used for the ground injection material used in tunnel construction, ground improvement work and water stop construction in various civil engineering works, sufficient construction time is taken and the permeability is excellent, so the injectability is improved. It becomes possible to inject into geological ground that was difficult to adapt. Curing after injection is quick, the movement of the injection point is quick, and the workability is greatly improved.

  By using the injecting material of the present invention, it penetrates into and solidifies into a gap of about several μm, thereby improving the water barrier property and maintaining its effect for a long period of time, and obtaining an effect excellent in long-term durability. It is done.

Claims (6)

An injection material for a one-shot system comprising cement, blast furnace slag, calcium aluminosilicate glass, gypsum, a setting regulator, and a water reducing agent in the following proportions.
(1) The ratio of cement to blast furnace slag is 3 to 30 parts by mass of cement: blast furnace slag 97 to 70
Part (2) The amount of gypsum used is 50 to 100 parts by mass of calcium aluminosilicate glass.
200 parts by mass (3) The total proportion of cement and blast furnace slag and the total of calcium aluminosilicate glass and gypsum is 90 to 99 parts by mass of cement and blast furnace slag: 10 to 1 parts by mass of calcium aluminosilicate glass and gypsum (4) 100 parts by mass of organic acid and 50 carbonates
The amount of the setting regulator comprising ~ 1000 parts by mass is 0.05 to 2 parts by mass (5) of the water reducing agent with respect to 100 parts by mass in total of cement, blast furnace slag, calcium aluminosilicate glass, and gypsum. The amount used is 12-30 parts by mass with respect to 100 parts by mass of cement. The injection material for a one-shot system according to claim 1, wherein the water reducing agent is a melamine sulfonic acid formalin condensate salt system. The injection material for a one-shot method according to claim 1 or 2, wherein an average particle diameter is 10 µm or less. Cement, blast furnace slag, calcium aluminosilicate glass, gypsum, setting modifier, water reducing agent,
And a one-shot injection method in which water is premixed and injected at the following ratio.
(1) The ratio of cement to blast furnace slag is 3 to 30 parts by mass of cement: blast furnace slag 97 to 70
Part (2) The amount of gypsum used is 50 to 100 parts by mass of calcium aluminosilicate glass.
200 parts by mass (3) The total proportion of cement and blast furnace slag and the total of calcium aluminosilicate glass and gypsum is 90 to 99 parts by mass of cement and blast furnace slag: 10 to 1 parts by mass of calcium aluminosilicate glass and gypsum (4) 100 parts by mass of organic acid and 50 carbonates
The amount of the setting regulator comprising ~ 1000 parts by mass is 0.05 to 2 parts by mass (5) of the water reducing agent with respect to 100 parts by mass in total of cement, blast furnace slag, calcium aluminosilicate glass, and gypsum. The amount used is 12 to 30 parts by mass with respect to 100 parts by mass of cement. (6) The amount of water used is 100 to 1000 parts by mass with respect to a total of 100 parts by mass of cement, blast furnace slag, calcium aluminosilicate glass, and gypsum. The one-shot injection method according to claim 4, wherein the water reducing agent is a melamine sulfonic acid formalin condensate salt system. The one-shot injection method according to claim 4 or 5, wherein the average particle diameter is 10 µm or less.