JP2002212558A - Grouting material for void filling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a grouting material for void filling, which reduces bleeding, increases adhesion, promotes hardening in a state, in which development of early strength is not retarded in comparison with a cement system, and high consolidation strength is obtained by adding a water glass to a tacky suspension composed of slag, lime and bentonite. SOLUTION: This grouting material for void filling is obtained by adding 1.7-8.4 kg/m3 calculated as SiO2 of water glass to the tacky suspension composed of slag, lime and bentonite, is made into a plastic state having <13 cm flow value and 0% bleeding, or into a flow state having >=13 cm flow value and 1-5% bleeding so that hardening is promoted in a state not to retard development of early strength and high agglomeration strength is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grout material filled with voids, and is used as a pretreatment in filling a cavity in a ground, a laying pipe around a structure such as a tunnel, or an injection method such as a double packer method. The present invention relates to a void-filled grout material suitable for injection of water.

[0002]

2. Description of the Related Art Heretofore, it has been conventionally used to fill a cavity or a laying pipe formed around a structure such as a large gap or a tunnel in the ground, or to be used in an injection method such as a double packer method. As a grout to be injected for the treatment, a cement-bentonite liquid (hereinafter, referred to as CB grout) in which cement and bentonite are combined so as to have a tackiness and prevent breathing of the cement suspension has been used. .

[0003] Injection filling of CB grout is usually made by swelling bentonite in water, and then adding cement to the resulting mixture to form an adhesive grout in which breathing is suppressed to 1 to 5%.
It is performed in a one-liquid system in which injection and filling are performed by one pump.

[0004] This CB grout can be easily obtained from ordinary cement which is usually used as a main cement, and hardening manifests in about 8 to 9 hours and is excellent in workability. , Has been used many times.

When cement is added to the CB grout after the bentonite is swollen with water to give tackiness, the bentonite causes a certain gelling reaction with an alkali component mainly composed of calcium hydroxide in the cement. Since the tackiness is increased, a tacky grout with less breathing can be obtained.

[0006] However, bentonite which is usually used does not use potassium-based bentonite but generally employs sodium-based bentonite having a high swelling property. Under the influence of the cement, the compatibility with the cement is poor, and the hardening of the cement tends to be inhibited.

For this reason, CB grout requires a large amount of cement in order to obtain a certain strength. However, since a large amount of cement cannot be used from the viewpoint of formulation, high strength is eventually obtained. There is a problem that grout cannot be obtained.

However, when the necessity of filling the cavity existing in the vicinity of a structure such as a large gap or a tunnel in the ground or a laying pipe becomes high recently, the above-described problem occurs. There is a need to develop a grout material that can be quickly improved to achieve an early strength equal to or higher than that of cement, and that maintain desired strength over a longer period than cement.

[0009]

SUMMARY OF THE INVENTION The present invention is proposed in view of the above situation, and is based on the use of slag such as granulated blast furnace slag powder instead of cement having poor compatibility with bentonite. In order to effectively utilize the inherent hydraulic properties of slag, it is activated by adding lime as an alkaline stimulant, which is compatible with sodium-based bentonite, which effectively promotes slag hardening. And the factors that hinder the development of hardening as a grout material are eliminated.

Also, by adding water glass which exhibits alkalinity but has almost no effect as an alkali stimulant for hardening slag, it is possible to promote the development of early strength and at the same time to enhance the tackiness. The above-mentioned problems are completely solved by adding the knowledge newly clarified by the inventors to the above.

That is, the present invention comprises a viscous suspension composed of slag, lime and bentonite, to which water glass is added to reduce the bleeding and improve the viscous property, while improving the viscous property. In addition, the present invention provides a void-filled grout material capable of accelerating hardening in a state where the development of early strength is not slowed down and finally obtaining high consolidation strength.

[0012]

The void-filled grout material according to the first aspect of the present invention is a void-filled grout material composed of a viscous suspension composed of slag, lime and bentonite, which is expressed in terms of SiO _2. 1.7 to 8.4 kg / m ^{3 in} value
It is characterized by the addition of water glass, and promotes curing in a state where the development of early strength does not slow down,
It is possible to increase the adhesiveness by reducing the breathing and finally obtain a high consolidation strength.

[0013] The void-filled grout material according to the second aspect of the present invention is the void-filled grout material according to the first aspect, wherein the adhesive A suspension comprising slag and lime, bentonite and water glass are used. Mix the two liquids with the Sex B suspension to a flow value of less than 13 cm and zero breathing.
%, And in addition to the above function, the grout material itself is transformed into a liquid state by pressurization of a pump or the like and can be easily fluidized while being self-supporting.

According to a third aspect of the present invention, there is provided the void-filled grout material according to the first aspect, which is a liquid of an adhesive suspension comprising slag, lime and bentonite. It is characterized by a fluidized state with a value of 13 cm or more and a breathing of 1 to 5%, and in addition to the above functions, the same construction as the conventional CB grout is enabled.

[0015]

DETAILED DESCRIPTION OF THE INVENTION A void-filled grout according to the invention is a void-filled grout, which basically consists of a sticky suspension of slag, lime and bentonite,
It is characterized by adding 1.7 to 8.4 kg / m ³ of water glass in terms of SiO ₂ , and specifically, comprises a viscous A suspension composed of slag and lime, bentonite and water glass. After mixing the two liquids with the viscous B suspension, the mixture was filled to a flow value of less than 13 cm and the breathing was 0%.
Or a viscous suspension composed of slag, lime and bentonite, which has a flow value of 13 cm or more and has a flow rate of 1 to 5%.

Hereinafter, embodiments of the present invention will be described in detail based on experimental results for verifying the present invention.

The basic principle of the present invention is to construct a viscous suspension using slag such as granulated blast furnace slag instead of cement which is incompatible with bentonite, and to provide the latent hydraulic property inherently provided by the slag. In order to make effective use of the properties of lime, it is activated by adding lime as an alkaline stimulant, thereby improving the compatibility with sodium-based bentonite, which promotes the curing of slag efficiently, and develops curing as a grout material In addition to eliminating the factors that hinder slag, the addition of water glass, which has almost no effect as an alkali stimulant for hardening the slag, promotes the early development of strength and at the same time increases the tackiness. It is built from the knowledge that it can be done.

Therefore, in the first experiment, a suspension was formed based on slag and lime, and it was confirmed whether desired adhesion was exhibited by adding bentonite or water glass to the suspension. .

It has been known that slag exhibits latent hydraulic properties and hardens when an alkali stimulant is added. Typical examples of the alkali stimulant include cement, lime, and caustic soda. The material used in this experiment was "Serament" (product name, manufactured by Daiichi Cement Co., Ltd.) as slag, and "Special" (slaked lime) as lime from the above as an alkali stimulant. (Made by Dowa Calfin Co., Ltd.).

"Super clay" (trade name) is used as bentonite to be added thereto, and SiO ₂ , 25.3%, Na ₂ O, 8.3%, specific gravity, .33, water glass contains SiO ₂ per liter
Contains 336 g of slag, which has a high alkalinity (PH11 to 12) with a molar ratio of about 2.5 or more, but has almost no practical effect as an alkali stimulant for slag. The cement suspension is composed of ordinary cement.

In this experiment, the amount of sticking was confirmed by the amount of breathing when bentonite or water glass was added to the slag-lime suspension and the cement suspension of the comparative example. The experimental results are as shown in the table of FIG. 1. In the table, the less the breathing, the lower the adhesive force (amount).
Means greater.

In this experiment, when adding bentonite, the bentonite was added to water, and the mixture was sufficiently stirred and swelled, and then slag-lime or cement was added. In addition, when water glass is added, the adhesion product (hydrous silicate gel) is adjusted by putting the water glass in a slag lime suspension or a cement suspension and stirring well.

Breathing showing the results after the experiment was 20
The mixed solution was put in a 0 ml measuring cylinder and sealed, and the synergic water after 24 hours was measured and indicated by (ml).

According to the experimental results shown in Table 1, the experimental N
o. No. 4 slag-lime suspension and experiment no. In the case of only one cement suspension, 95 (ml), 99 (ml)
And the breathing is about 50%, which is very high. However, when a small amount of bentonite or water glass is added, a large amount of stickiness is produced in both slag and lime suspensions and cement suspensions. Since the product is formed, it has been confirmed that each value of the breathing is significantly reduced.

From this fact, it is known that, in addition to the fact that slag is exposed to an alkali stimulant to exhibit latent hydraulic properties and hardens, bentonite or water glass is added to the slag lime suspension. In the experiment No. of the comparative example, it was found that an additional action and effect occurred between the lime and the bentonite or the water glass. A few,
Experiment N in which bentonite was added to slagou lime suspension N
o. Experiment Nos. 5 to 7 to which water glass was added. Comparing 8 to 10, it is clear from the fact that the value of breathing is reduced. ,

In particular, water glass, which has little effect as an alkali stimulant, has less bleeding and produces more sticky products than bentonite, which is generally said to have a very high degree of swelling. It is apparent that the following effects are exhibited.

(1) By using a small amount of water glass together with lime, the latent hydraulic reaction of slag is stimulated to promote the development of early strength. (2) The lime and water glass in the grout react almost instantaneously with a gel time of 1 to 2 seconds or less to produce a hydrous silica gel.

Thus, the resulting hydrous silica gel is
It is a sticky substance containing a large amount of water and increases the stickiness like bentonite. Therefore, the above-mentioned experiment was performed by the synergistic effect of the stickiness of bentonite and the hydrated silica gel by the reaction of lime and water glass. It is possible to obtain grout with less bleeding as a result.

As is clear from the above experimental results, it is clear that the addition of a small amount of water glass to the suspension composed of slag, lime and bentonite functions to increase the tackiness while reducing bleeding. Therefore, it can be verified that the void-filled grout according to the present invention exhibits desired tackiness.

Although slag exhibits latent hydraulicity by lime alkaline stimulant, there is also a known problem that its hardening reaction is very slow and its early strength is inferior to that of cement. However, in the present invention, based on the novel findings of the present inventors, the addition of water glass to the glass promotes the development of early strength and at the same time increases the adhesiveness.

Therefore, in the next experiment, the breathing, flow value, time until the onset of hardening and long-term uniaxial compression of a grout material obtained by adding water glass to a sticky suspension composed of slag, lime and bentonite were examined. The strength was measured to determine whether the void-filled grout according to the invention developed as a desired hardening at a rate equal to or greater than the early strength development in cement systems.

In this experiment, a slag and lime were used as a base to form a viscous suspension, to which bentonite or water glass was added to form a void-filled grout material according to the present invention. , As a comparative example.

The viscosity of the grout was measured by filling a CB grout in a cylinder having an inner diameter of 80 mm and a height of 80 mm placed on an acrylic plate, then lifting the cylinder gently, and measuring the spread (diameter) of the grout at that time. And measured in a cylindrical flown method, expressed in units (cm).

The determination of the time until the grout hardens is determined by the asphalt penetration test method (JIS K253).
0-1961), and the mass is 180 g,
The static penetration resistance was measured using a penetration cone with a tip angle of 15 °, and the penetration value was 250 mm (estimated compressive strength 0.5 N /
cm ² ).

The breathing was performed in the same manner as in the above experiment.
The grout material was put in a 00 ml measuring cylinder, sealed and placed, and the synergic water after 3 hours was measured and indicated in%.

The experimental results shown in the table of FIG.
These are representative results of measurements on an embodiment of a grout material configured plastically with less than 3 cm and breathing at 0%. The experimental results shown in the table of FIG.
5 shows typical results of measurement in an embodiment of a grout material configured to be in a fluid state with the breathing being in the range of 1 to 5% by setting m or more.

As shown in the table of FIG. 2, in the embodiment of the grout material constituted by the plastic grout, the adhesive A suspension (0.5 m ³ ) composed of slag and lime, bentonite and water glass were used. A two-liquid injection method is used in which two liquids with the adhesive B suspension (0.5 m ³ ) are mixed and filled.

As shown in the table of FIG. 2, the experimental results of the grout material which is plasticized by setting the breathing to 0% and the flow value to less than 13 cm show that the time required for the grout to harden is the same as that of the comparative example. Experiment N for taste
o. As shown by 11 and 12, the CB grout material is 8 to 9
Time. On the other hand, in Experiment No. The sticky suspension consisting of slag, lime and bentonite shown in FIG.
The curing reaction became very slow in 5.5 hours. As shown in Fig. 20, even if the amount of lime was increased, it could not be improved to 14.0 hours.

Furthermore, even when water glass is added while reducing the amount of bentonite to adjust the above-mentioned breathing and flow values, the addition of water glass is 0.84.
kg, the experiment No. As shown by the measured values of Test Nos. 14 and 21, the pressure was only reduced to 13.5 hours and 13.0 hours, and the level of the CB grout material was not reached. 20 kg of lime like 14
It was also found that when the amount was small, the adhesive strength was reduced and the flow value was increased.

However, even if an attempt is made to shorten the onset time of hardening by increasing the amount of water glass added, the onset time of hardening becomes faster as the amount of water glass increases. 1
As the measured values of 5, 22 show, the amount of SiO ₂ was 3.36.
While the same time as that of CB grout was obtained at about the same level as that of CB grout, experiment Nos. It is 3 hours very fast like the measured values of 18, 25,
Even if the O ₂ amount was increased beyond 8.7 kg, the experiment N
o. As shown by the measured values of Nos. 19 and 26, it was confirmed that not only the effect was not so much recognized but also that the flow value was increased and the adhesive strength was reduced.

On the other hand, looking at the measured values of the uniaxial compressive strength,
The uniaxial compressive strength of the viscous suspension comprising slag, lime and bentonite according to the present embodiment is much higher than that of B grout.
o. 400 kg of slag and 20 to 40 kg of lime which are less than the 500 kg of cement shown in the comparative example 11
Nevertheless, it is as high as about 1.5 to 2 times, and it is verified that the final consolidated strength is excellent.

With respect to the addition of water glass, a higher uniaxial compressive strength was exhibited after 7 days than when no glass was added.
Experiment No. As the measured values of 19 and 26 show the tendency, when the amount of added water glass increases over a long period (28 days), the strength of the grout material slightly decreases and the tendency increases.

As is clear from the above experimental results, the void-filled grout material composed of the viscous suspension composed of slag, lime and bentonite is 1.7 to 1.7 in terms of SiO _2.
By adding 8.4 kg / m ³ of water glass, the desired hardening is developed at a speed longer than the time of the early strength development in the cement system, and a high value is exhibited even in the long-term uniaxial compressive strength. To 0% and the flow value to 13cm
It can be confirmed that the intended purpose can be achieved even if the composition is made to be less plastic.

In this embodiment, two liquids of the adhesive A suspension composed of slag and lime and the adhesive B suspension composed of bentonite and water glass are mixed and then filled. The above experimental results were measured by adopting the injection method, and it was clarified that filling by the two-liquid injection method was possible.

The experimental results shown in the table of FIG. 3 are representative results of the measurement in the embodiment of the grout material in a fluid state with the breathing in the range of 1 to 5% and the flow value of 13 cm or more. Is shown.

As shown in the table of FIG. 3, in the embodiment of the grout material formed into a fluid grout, a one-liquid injection method is employed.

The fluid grout shown in the table of FIG. 3 shows almost the same properties as the plastic grout shown in the table of FIG. 2, and thus no detailed experimental example is shown. No. By adjusting the bentonite to 23 kg and the water glass to 1.68 kg while decreasing the lime so that the measured value of 27 shows the tendency, the breathing is adjusted to 1 to 5%, and the flow value is adjusted to 13 cm or more. The time until the grout hardens is slightly slower than that of the CB grout, and the uniaxial compressive strength is also slightly lower.

On the other hand, in Experiment No. The measured value of 28 was to adjust bentonite and water glass to 15 kg while increasing lime to 40 kg, to adjust water glass to 5.04 kg in terms of SiO ₂ , and to reduce breathing by 3.3%.
By setting the flow value to 18.4 cm, the time required for the grout to harden is significantly shortened, and it is suggested that the uniaxial compressive strength can be set to a value higher than that of the CB grout.

On the other hand, in Experiment No. As shown in Comparative Example No. 29, when water glass was not added, lime and bentonite were used in Experiment Nos. Even if it is almost the same as 27, even if the value of breathing and the uniaxial compressive strength increase, the time until the grout hardens will be extremely extended to 20.5 hours. Improper.

As is apparent from the above experimental results, the void-filled grout material composed of the viscous suspension composed of slag, lime and bentonite is 1.7 to 1.7 in terms of SiO _2.
By adding 8.4 kg / m ³ of water glass to form a fluid with a breathing rate of 1 to 5% and a flow value of 13 cm or more, the same construction as the conventional CB grout is possible while the final construction is possible. It was confirmed that the compaction strength could be improved.

[0051] by was confirmed from the above experimental results, void filling grout is slag, water glass amount added in the adhesive suspension of lime and bentonite, relative to grout 1 m ³ units In the case of 0.8 kg in terms of SiO ₂ , no early strength was exhibited and 1.7 k
By adding more than g of water glass, an early strength can be exhibited in a time approximately equal to or longer than that of the conventional CB grout.

On the other hand, as the amount of SiO ₂ is increased, the development of early strength is promoted up to the amount of SiO ₂ of 8.4 kg, but when it is more than that, the effect is not so large, and in addition, the adhesive strength tends to decrease. Show. In addition to this, the strength of the void-filled grout material, when water glass is added, the early strength after 7 days is large, but in the long term after 28 days, the strength tends to decrease conversely, and the amount of SiO ₂ is 8. When it is 4 kg or more, the tendency becomes large.

Therefore, the void-filled grout material according to the present invention can be used to determine the amount of water glass added to the grout by comprehensively judging the tackiness, the flow value, the time until the effect of the grout appears, and the consolidation strength. and 1.7 in terms of SiO ₂ values
The range is limited to 8.4 kg / m ³ .

The amount of lime to be added is set to 20 to 40 kg or 1 to 5% of slag in units of 1 m ³ of grout. .

In addition, the slag in the present invention is not particularly limited as an embodiment, but it is appropriate to use a slag having a degree of fineness equal to or higher than that of cement. However, use of slaked lime is preferred, and there is no particular limitation on the difference in quality depending on the place of production.

Similarly, as the bentonite, one having a montmorillonite clay mineral as a main component is employed, but is not limited thereto.

Further, with respect to the water glass, the molar ratio is 2.
The number is not particularly limited as long as it is 5 or more, but preferably a molar ratio of 2.8 to 4.0 is optimal.

In addition to the above, the void-filling grout material according to the present invention includes fine powders of primary minerals such as sand, fly ash, rock, limestone, and dolomite; clay minerals such as porcelain clay excluding bentonite; A foaming agent such as a foaming agent or aluminum powder, a retarder, an early-strength developing material, and the like can be added according to the respective circumstances and the purpose of filling.

As described above, the void-filled grout material according to the present invention is the same as the void-filled grout material composed of the viscous suspension composed of slag, lime and bentonite.
By adding 1.7 to 8.4 kg / m ³ of water glass in terms of O ₂ , curing is accelerated in a state where the development of early strength is not slowed down, and bleeding is reduced to increase the adhesiveness and the final High consolidation strength can be obtained.

Further, the void-filled grout material according to the present invention comprises:
It is possible to configure a plasticity in which the flow value is less than 13 cm and the breathing is adjusted to 0% and the pressure-sensitive adhesive is adjusted. In this case, a sticky A suspension composed of slag and lime, bentonite and water glass are used. And the adhesive A suspension and the adhesive B suspension are pumped by separate pumps and merged and mixed near the injection port through an injection hose or an injection pipe. It is appropriate to use a two-pack injection method for filling.

However, water glass is not limited to being added as a sticky B suspension, but may be added to a sticky A suspension depending on the composition.

Thus, the above-mentioned plastically formed void-filled grout material is independent of the grout material itself, but has the property of being easily fluidized by being pressurized by a pump or the like. In the injection, grout transformed into a plastic state is injected and filled into a large gap in the target ground or a cavity around the structure.

The injection ratio between the viscous A suspension and the viscous B suspension in the present invention is not particularly limited, and may vary depending on the composition such as the presence or absence of additives, the viscosity, etc. It is also optional to perform the injection or with a proportional injection where one suspension is greater than the other.

As described above, the void-filled grout according to the present invention is the same as the above-mentioned void-filled grout, except that the adhesive-A suspension comprising slag and lime and the adhesive-B suspension comprising bentonite and water glass. After the two liquids are mixed, the mixture is filled to make the flow value less than 13 cm and the breathing is made to have a plasticity of 0%. In addition to the above functions, the grout material itself is free standing. It is transformed into a liquid by pressurization of a pump or the like, and is easily fluidized, so that it can be injected into a large gap in a target ground or a cavity around a structure.

In addition, the void-filled grout material according to the present invention is composed of a sticky suspension composed of slag, lime and bentonite, and is 1.7 to 8.4 kg / m ^{3 in} terms of SiO _2.
The above-mentioned void-filled grout material to which the water glass is added is configured in a fluid state with a breathing rate of 1 to 5% and a flow value of 13 cm or more. It exhibits excellent compaction strength.

Although the present invention has been described in detail based on the embodiments, the grout material filled with voids according to the present invention is not limited to the above embodiments, and slag, lime, bentonite, It goes without saying that various changes can be made to the type of the sexual suspension and the like without departing from the spirit of the present invention.

[0067]

The void-filled grout material according to the first aspect of the present invention is a void-filled grout material composed of an adhesive suspension comprising slag, lime and bentonite.
It is characterized by the addition of 1.7 to 8.4 kg / m ³ of water glass in terms of iO _2, so it promotes hardening in a state where the development of early strength is not slowed down, and reduces bleeding to improve adhesion. And the effect of finally obtaining a high consolidation strength is exhibited.

The void-filled grout according to the second aspect of the present invention is the void-filled grout according to the first aspect, wherein the adhesive-A suspension comprising slag and lime, bentonite and water glass. Mix the two liquids with the Sex B suspension to a flow value of less than 13 cm and zero breathing.
%, And in addition to the above-mentioned effects, the grout material itself exhibits the effect of being transformed into a liquid state by the pressure of a pump or the like and being easily fluidized while being independent. .

The void-filled grout according to the third aspect of the present invention is the void-filled grout according to the first aspect, which is a one-part solution of an adhesive suspension comprising slag, lime and bentonite. It is characterized by a fluidized state with a value of 13 cm or more and a breathing of 1 to 5%. In addition to the above-mentioned effects, it has the effect of enabling the same construction as the conventional CB grout.

[Brief description of the drawings]

FIG. 1 is a table of experimental results confirming the generation of sticky products to verify the void-filled grout material according to the present invention.

FIG. 2 is a table of experimental results for confirming a flow value, a time until the onset of hardening, and a uniaxial compressive strength in order to verify a void-filled grout material according to the present invention configured to be plastic.

FIG. 3 is a table of experimental results for confirming a flow value, a time until onset of hardening, and a uniaxial compressive strength in order to verify a void-filled grout material according to the present invention configured in a fluid state.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C04B 111: 70 C04B 111: 70 C09K 103: 00 C09K 103: 00 F term (Reference) 2D040 AA06 AB01 BB03 BB09 CA02 CA03 CA04 CA10 CB03 CD08 4G012 PA03 PA06 PA11 PA29 PB06 4H026 CA02 CA03 CA05 CA06 CC06

Claims (3)

[Claims] 1. A void-filled grout comprising a sticky suspension consisting of slag, lime and bentonite,
A void-filled grout material to which 1.7 to 8.4 kg / m ³ of water glass in terms of SiO ₂ is added. 2. A two-part mixture of a sticky A suspension consisting of slag and lime and a sticky B suspension consisting of bentonite and water glass to a flow value of less than 13 cm and a breathing of 0%. The void-filled grout material according to claim 1, wherein the grout material is formed in a plasticized state. 3. A viscous suspension comprising slag, lime and bentonite, wherein the liquid has a flow value of 13 cm or more and has a breathing rate of 1 to 5%. Item 7. The void-filled grout material according to Item 1.