JP6970385B2 - Cement-based solidifying material slurry and its manufacturing method - Google Patents

Description

The present invention relates to a method for producing a slurry of a cement-based solidifying material widely used for ground improvement from a deep layer to a surface layer. In particular, the slurry has good fluidity even in a high temperature environment, there is little lumps generated in the slurry, there is no blockage in the piping path of the construction machine or the ejection nozzle, and the cement-based solidifying material slurry has excellent workability. The manufacturing method is provided.

In ground improvement using cement-based solidifying material, for ground improvement from deep layer to surface layer, a construction method is widely used in which cement-based solidifying material and water are kneaded to form a cement-based solidifying material slurry, which is mixed with deep layer and surface layer soil. It has been adopted. For example, a method of pumping this slurry to the tip of an excavating machine and mixing and stirring the slurry and soil with a stirring blade to form solidified soil has been conventionally practiced. Gypsum is generally added to the cement-based solidifying material used for such ground improvement in order to promote solidification in soft soil, organic soil, volcanic ash cohesive soil and the like. Gypsum has the effect of effectively solidifying soft soil, highly organic soil, and volcanic ash cohesive soil by reacting with the aluminate phase in cement to form ettringite. For this reason, gypsum is generally blended with cement and blast furnace slag in the cement-based solidifying material.

On the other hand, in the ground improvement method using the cement-based solidifying material slurry, the slurry in which the mass ratio of water to the cement-based solidifying material (hereinafter referred to as the water-based solidifying material ratio) is in the range of 50% or more to 150% or less is used in summer. In construction in a high temperature environment, the amount of ettringite produced by the reaction between the aluminate phase in cement and gypsum increases, the fluidity of the slurry decreases, and lumps may be formed in the slurry. For this reason, a trouble may occur in which the filter of the pumping path and the injection nozzle at the tip of the excavator are blocked.

Therefore, at the site, measures are taken to reduce the slurry concentration by increasing the ratio of water solidified material. However, if the ratio of the water solidifying material is increased, the amount of the cement-based solidifying material added to achieve the target strength increases, which leads to an increase in material cost and construction cost. Further, in the soil where the amount of the cement-based solidifying material added to obtain the required improved body strength is large, it may be difficult to obtain the required improved body strength if the ratio of the water solidifying material is increased.

On the other hand, in order to avoid such a decrease in fluidity of cement and cement-based solidifying material slurries, it is conceivable to install a sieve at the discharge port of a mixer for kneading the slurry to remove lumps generated. When a large amount of lumps that hinder the construction is generated, there is a problem that a large amount of lumps are accumulated on this sieve and it takes time and effort to clean them.

In order to solve these problems, for example, the following measures have been attempted.
(1) In Japanese Patent Application Laid-Open No. 2004-231479 (Patent Document 1), the sulfur trioxide content in the cement-based solidifying material composition is 6 to 15% by mass, and the chlorine content is 0.1 to 2.0% by mass. It is proposed that by adjusting the range, good workability can be obtained without lowering the fluidity even when the slurry temperature is high.
(2) In Japanese Patent Application Laid-Open No. 2001-131547 (Patent Document 2), attention is paid to the chemical composition of Portland cement constituting the cement-based solidifying material, and the water-soluble alkali content (Na ₂ O equivalent) is less than 0.35% by weight. Moreover, it is proposed that by reducing the amount of semi-hydrated gypsum to less than 3% by weight, it becomes difficult to form lumps in the slurry.
(3) In Japanese Patent Application Laid-Open No. 2010-159347 (Patent Document 3), in order to prevent a decrease in fluidity when a soil solidifying material containing slaked lime is made into a slurry, 5 to 40% by volume of particles having a slaked lime particle size of 30 μm or more are used. It is proposed to be in the range, more preferably 10 to 30% by volume.
However, all of these methods have viscosity and lumps when producing a cement-based solidifying material slurry according to the construction conditions (assumed temperature, design water solidifying material ratio, kneading conditions, etc.) at the actual construction site. It was difficult to determine in advance the presence or absence of.

Further, in Japanese Patent Application Laid-Open No. 2005-233792 (Patent Document 4), in order to perform quality control of soil-stabilized soil quickly and accurately, the diameter of the discharge port of the P funnel is optimized and the shielding lid of the input port is used. Although a simple viscosity measuring instrument provided with the above is described, it is possible to estimate the viscosity of the cement-based solidifying material slurry using this measuring instrument, but it is not possible to grasp the amount of lumps generated in the slurry. Have difficulty.

Japanese Unexamined Patent Publication No. 2004-231479 Japanese Unexamined Patent Publication No. 2001-131547 Japanese Unexamined Patent Publication No. 2010-159347 Japanese Unexamined Patent Publication No. 2005-233792

The above-mentioned conventional technique is used to generate a cement-based solidifying material slurry produced in a slurry under construction conditions such as environmental temperature, slurry temperature, mixing water temperature, kneading conditions, and water solidifying material ratio at an actual site. It is not fully recognized that the fluidity of the slurry is greatly affected by the amount of the lumpy substance, and it is not possible to suppress the formation of the lumpy substance to control the fluidity of the slurry.

The cement-based solidifying material slurry of the present invention has a kneading temperature of 30 ° C. in order to maintain good fluidity of the slurry in a high temperature environment according to the construction conditions of ground improvement using the slurry under high temperature conditions in summer. In the above, the ratio of the lumps remaining on the net sieve when passed through the net sieve having a predetermined opening is set to be a certain amount or less. As shown in Examples described later, a close relationship is observed between the proportion of lumps remaining on the mesh sieve and the fluidity of the slurry. The cement-based solidifying material slurry of the present invention is obtained by measuring the proportion of lumps remaining on a predetermined mesh sieve and further controlling the ratio so that the slurry has good fluidity.

The present invention relates to a cement-based solidifying material slurry and a method for producing the same, which solves the above-mentioned problems by the following configurations.
[1] Slurry of 50% to 300% of water solidified material of cement-based solidifying material containing 30 to 86% by mass of Portland cement clinker, 10 to 50% by mass of blast furnace slag, and 4 to 20% by mass of gypsum (anhydrous gypsum equivalent). In the above, when the kneading temperature is 30 ° C. or higher and the mesh is passed through a mesh sieve having an opening of 2 mm, the amount of lumps remaining on the mesh sieve is 3.5% by mass or less of the whole slurry, and / and the opening. A cement-based solidifying material slurry, characterized in that the amount of lumps remaining on the mesh sieve when the slurry is passed through a 1 mm mesh sieve is 5.0% by mass or less of the entire slurry.
[2] The cement-based solidifying material slurry according to the above [1], wherein the cement-based solidifying material contains limestone and / and fly ash as a mixed component in a small amount.
[3] A cement-based solidifying material containing 30 to 86% by mass of Portland cement clinker, 10 to 50% by mass of blast furnace slag, and 4 to 20% by mass of gypsum (anhydrous plaster equivalent) is kneaded and water is added to make a water solidifying material ratio of 50. In the method for producing a slurry of% to 300%, the cement-based solidifying material having a temperature of 30 to 40 ° C. and kneading water are used, and either the water-solidifying material ratio or the kneading method is used depending on the material of the cement-based solidifying material. Or by adjusting both, when the slurry after kneading is passed through a mesh sieve with an opening of 2 mm at a kneading temperature of 30 ° C. or higher, the proportion of lumps remaining on the mesh sieve is 3 of the entire slurry. Slurry of .5% by mass or less, and / and the proportion of lumps remaining on the mesh sieve when the slurry is passed through a mesh sieve having an opening of 1 mm is 5.0% by mass or less of the whole slurry. A method for producing a cement-based solidifying material slurry.
[4] The method for producing a cement-based solidifying material slurry according to the above [3], which is used by adding a dispersant to kneaded water.

[Cement-based solidifying material slurry]
The cement-based solidifying material slurry of the present invention contains 30 to 86% by mass of Portland cement clinker, 10 to 50% by mass of blast furnace slag, and 4 to 20% by mass of gypsum (anhydrous gypsum equivalent). A slurry having the following characteristics (a) or / and (b) at a kneading temperature of 30 ° C. or higher in a % to 300% slurry.
(A) The amount of lumps remaining on the mesh sieve when the mesh is passed through a mesh sieve having an opening of 2 mm is 3.5% by mass or less of the entire slurry.
(B) The amount of lumps remaining on the mesh sieve when the mesh is passed through a mesh sieve having an opening of 1 mm is 5.0% by mass or less of the entire slurry.

In the cement-based solidifying material slurry, as shown in Examples described later, at a kneading temperature of 30 ° C. or higher, (A) the lumps remaining on the mesh sieve when the opening is passed through the mesh sieve of 2 mm are slurry. If it is more than 3.5% by mass of the whole slurry, or (B) the amount of lumps remaining on the mesh sieve when the opening is passed through the mesh sieve of 1 mm is more than 5.0% by mass of the whole slurry. The slurry flow time of the flow test becomes long, and the fluidity of the slurry decreases. On the other hand, if the slurry is in either the above (a) or (b) state, or in both the above (a) and the above (b) states, it has good fluidity and is in the above (a). The liquidity is even better in both the above (b) and (b) states.

Specifically, when the cement-based solidifying material slurry is passed through a mesh sieve having an opening of 2 mm at a kneading temperature of 30 ° C. or higher, the mass of the lumps remaining on the mesh sieve is increased. When it is 3.5% by mass or less of the total mass of the slurry, the viscosity of the slurry is low immediately after kneading and 15 minutes after the kneading, and the slurry has good fluidity.

On the other hand, when the proportion of the lumps remaining on the mesh sieve exceeds 3.5% by mass and is 5.0% by mass or less, the fluidity of the slurry immediately after kneading is good, but 15 minutes after kneading. After the lapse of time, the liquidity decreases. Further, when the proportion of the lumpy substance exceeds 5.0% by mass, the fluidity of the slurry is poor immediately after kneading.

Further, when the cement-based solidifying material slurry is passed through a mesh sieve having an opening of 1 mm, when the proportion of the lumps remaining on the mesh sieve is 5.0% by mass or less of the total mass of the slurry, the slurry is kneaded. Immediately after and 15 minutes after kneading, the slurry has low viscosity and good fluidity. On the other hand, when the proportion of the lumps remaining on the mesh sieve exceeds 5.0% by mass and 6.0% by mass or less, the fluidity of the slurry immediately after kneading is good, but 15 minutes have passed since kneading. After that, the fluidity of the slurry decreases. Furthermore, when the proportion of the lumpy substance exceeds 6.0% by mass, the fluidity of the slurry is poor immediately after kneading.

The net sieves used to measure the residual ratio of the lumps are those with a nominal opening of 1 mm and 2 mm specified in the standard (JIS Z 8801-1: Test Sieve Part 1 Metal Net Sieve). .. The material is preferably made of stainless steel or brass, but is not limited thereto.

[Cement-based solidifying material]
The constituent material of the cement-based solidifying material of the present invention comprises Portland cement or mixed cement, blast furnace slag fine powder, a mixture of gypsum, or a mixed pulverized product of Portland cement clinker, blast furnace slag, and gypsum. Further, as the cement-based solidifying material, fly ash, modified coal ash, fine limestone powder, silica fume, stone powder, slaked lime and the like can be used as a small amount of mixed components. These small-quantity mixed components can be added when the cement-based solidifying material is mixed or mixed and pulverized.

The cement-based solidifying material of the present invention contains 30 to 86% by mass of Portland cement clinker and 10 to 50% by mass of blast furnace slag, assuming that the total amount of the essential components Portland cement clinker, gypsum, and blast furnace slag is 100% by mass. , Gypsum (equivalent to anhydrous gypsum) is 4 to 20% by mass, preferably Portland cement clinker is 35 to 70% by mass, blast furnace slag is 12 to 45% by mass, and gypsum (equivalent to anhydrous gypsum) is 6 to 15% by mass. Is. When using blast furnace cement, the amount of blast furnace slag may be less than the above range.

As the cement, ordinary Portland cement, early-strength Portland cement, moderate heat Portland cement, low heat Portland cement and other Portland cement, or blast furnace cement, fly ash cement and silica fume cement mixed cement can be used. These clinker are used in mixed grinding.

As the gypsum, one or both of anhydrous gypsum, dihydrate gypsum, and semi-hydrated gypsum are used. Further, as the source of gypsum, natural anhydrous gypsum, flue gas desulfurized gypsum, hydrofluoric acid gypsum and the like are used. Fly ash that conforms to the standard (JIS A 6201: Fly ash for concrete type II) is used.

Blaine specific surface area of the cement solidifying material is preferably 2500~6000cm ² / g, is preferably further 3000~5000cm ² / g. When the brain specific surface area is 2500 cm ² / g or less, solid-liquid separation due to bleeding occurs when the slurry is made, which causes variations in the strength of the improved body and insufficient strength. When the brain specific surface area is 6000 cm ² / g or more, the fluidity decreases when kneading is performed in a region where the water solidifying material ratio is lower than 100%. The blast furnace slag fine powder added to the cement-based solidifying material ^{preferably has a brain specific surface area of 3000 to 6000 cm 2} / g. In the case of mixed crushing, uncrushed blast furnace slag can be used.

The cement-based solidifying material of the present invention can be obtained by mixing cement, blast furnace slag fine powder, gypsum, and a small amount of components. As the mixing device, a general mixing device such as a V-type mixer, a Procia mixer, a Henschel mixer, and a ribbon-type mixer can be used. In the case of mixed crushing, a cement-based solidifying material can be obtained by putting cement or cement clinker, blast furnace slag fine powder or blast furnace slag uncrushed material, gypsum and a small amount of mixed components into a crusher and crushing them. .. As the crusher, a ball mill, a vertical mill, a vibration mill or the like can be used.

Diethylene glycol and organic short fibers may be added in a small amount to the cement-based solidifying material of the present invention in order to further reduce the generation of dust generated when the cement-based solidifying material slurry is kneaded. As the organic short fibers, natural fibers such as pulp, polypropylene fibers, polyamide fibers, polyvinyl alcohol fibers and the like can be used. Further, from the viewpoint of not hindering the fluidity of the cement-based solidifying material slurry, the organic fiber preferably has a fiber length of 1 mm to 6 mm, and the amount added is 0.01% by mass to 0.2 with respect to the cement-based solidifying material. Percentage of mass is preferred.

Alumina cement, calcium aluminate-based fast-hardening material, and the like can be added to the cement-based solidifying material of the present invention when early curing is required. Specifically, for example, as the quick-hardening material, _{a mixture of pulverized calcium aluminate such as C 12} A ₇ and anhydrous gypsum, ultrafast-hardening cement, alumina cement and the like can be used. The fast-hardening material composed of a mixture of pulverized calcium aluminate and anhydrous gypsum contains pulverized calcium aluminate and anhydrous gypsum in a mass ratio of approximately 40:60 to 60:40. As a commercially available product, for example, Coca Ace Super (trade name) manufactured by Mitsubishi Materials Corporation can be used.

〔Production method〕
The cement-based solidifying material slurry of the present invention is produced by kneading the cement-based solidifying material with water to make a slurry. In this manufacturing method, a cement-based solidifying material having a temperature of 30 to 40 ° C. and kneading water are used, and either or both of the water-solidifying material ratio and the kneading method are used depending on the material of the cement-based solidifying material. It can be produced by selecting so that the ratio of the lumps remaining on the net sieve when passed through the sieve is within the range of the above (a) or the above (b).

For the production of the cement-based solidifying material slurry, a batch-type stirring / mixing mixer having a capacity of 50 to 1000 L, a continuous kneading mixer (manufactured by Putzmeister), or the like can be used in the field. Further, the slurry may be produced by using a lab stirrer, a hand mixer or the like.

A dispersant can be added during the production of the cement-based solidifying material slurry. This dispersant enhances the dispersibility of the particles of the cement-based solidifying material in the slurry, whereby the fluidity of the slurry can be improved. Examples of the dispersant include polycarboxylic acid-based, lignin sulphonic acid-based, naphthalene sulphonic acid-based, and melamine sulphonic acid-based. The amount added to the cement-based solidifying material is in the range of 0.01 to 1.0% by mass, and may be used by mixing with kneading water.

The cement-based solidifying material slurry of the present invention has good fluidity even in a high temperature environment in ground improvement using a cement-based solidifying material widely used for ground improvement from a deep layer to a surface layer. Specifically, under the condition of a kneading temperature of 30 ° C to 40 ° C, which is assumed in summer, the flow time in the Marsh Funnel viscometer is 100 seconds or less after 15 minutes of kneading in a slurry having a water solidifying material ratio of 60%. And the fluidity is good. The fluidity of the cement slurry is good if the flow time is 100 seconds or less in the fluidity test using the Marsh funnel cone specified in the European standard (EN445: Grout for prestressing tendons. Test methods). Is determined.

The cement-based solidifying material slurry of the present invention exerts a good effect in a range where the water solidifying material ratio is relatively low, specifically, in the range of 50% to 150%, and the water solidifying material ratio is 150% to 300%. In the range, the superiority in a high temperature environment decreases, but it can be used effectively.

Since the cement-based solidifying material slurry of the present invention does not generate lumps in the slurry, it is not blocked by the piping path of the construction machine or the ejection nozzle, and is excellent in workability. Further, the strength development of the improved soil is also good, and the required fluidity can be secured, so that the strength of the improved body is uniform.

Further, in the production method of the present invention, a predetermined net sieve is obtained by using kneading water at a predetermined temperature and adjusting either or both of the water solidifying material ratio and the kneading method according to the material of the cement-based solidifying material. Since the ratio of the lumps remaining on the net sieve when passed through may be within the range of (a) or (b) above, it is not necessary to use a special chemical or device, and it is easy to carry out. can do.

Hereinafter, examples of the present invention will be shown together with comparative examples. In addition,% about mass is mass%.
In Examples and the like, Portland cement, blast furnace slag fine powder and gypsum were mixed to prepare a cement-based solidifying material, but it may be prepared by mixed pulverization. The mesh sieve used in the examples and the like is made of stainless steel or brass with a nominal opening of 1 mm and 2 mm specified in the standard (JIS Z 8801-1: Test Sieve Part 1 Metal Sieve). ..

For the sieve residue, pour the kneaded cement-based solidifying material slurry into the above mesh sieve, measure the mass of the agglomerates and solidified substances remaining on the sieve, and calculate the ratio to the total mass of the solidifying material slurry (here, 1600 g). I asked. The flow time of the solidifying material slurry was measured by using a Marsh funnel viscometer (hereinafter abbreviated as a viscometer) until the container (500 mL) on the receiving side was full.

[Example 1]
1000 g of the cement-based solidifying material and 600 g of water shown in Table 1 were kneaded (water solidifying material ratio = 60%). The kneading method is as follows: the cement-based solidifying material and water whose temperature has been adjusted to 30 to 40 ° C. are put into a hovert mixer, kneaded at a rotation speed of 70 rpm for 30 seconds, and then the deposits on the bottom of the container are scraped off, and then further. A solidifying material slurry was prepared by kneading at a rotation speed of 70 rpm for 30 seconds. After measuring the kneading temperature of this solidifying material slurry, it was passed through a sieve having an opening of 1 mm or 2 mm, and the sieve residue remaining on the sieve was measured. Further, while closing the outlet of the viscometer with a finger, the solidifying material slurry that had passed through the sieve was poured into the main body of the viscometer, the blocked finger was released, and the time until the container on the receiving side was full was measured. The results are shown in Table 2. If the solidifying material slurry was blocked by the viscometer body, or if the flow time was 180 seconds or longer, measurement was not possible.

As a result of the experiment, when the mass of the mass remaining on the mesh sieve is 5.0% or less of the total mass of the slurry when the mesh is passed through a mesh sieve having an opening of 1 mm, it is immediately after kneading and after kneading. After 15 minutes from the above, the viscosity was low and no increase in lumps was observed. When the lumps exceeded 5.0% and 6.0% or less, the fluidity immediately after kneading was good, but the fluidity decreased 15 minutes after kneading. Further, when the lumps exceeded 6.0%, the fluidity was poor immediately after kneading, and the lumps also increased.

If the mass of the lumps remaining on the mesh sieve is 3.5% or less of the total mass of the slurry when the mesh is passed through a mesh sieve having an opening of 2 mm, immediately after kneading and 15 minutes have passed since the kneading. After that, the viscosity was low, and no increase in lumps was observed. When the lumps exceeded 3.5% and 5.0% or less, the fluidity immediately after kneading was good, but the fluidity decreased 15 minutes after kneading. Further, when the lumps exceeded 5.0%, the fluidity was poor immediately after kneading, and the lumps also increased.

As shown in Samples A1 to A5, lowering the temperature of the mixing water tends to lower the kneading temperature of the solidifying material slurry and improve the fluidity. Further, it can be seen that by lowering the temperature of the kneaded water to 34.0 ° C., the flow time 15 minutes after the kneading is reduced to 100 seconds or less, and the fluidity is improved. Further, by comparing Sample A2, Sample B2, and Sample C1, ^{if a cement-based solidifying material (symbol A) having a brain specific surface area of 4050 cm 2} / g is used, the flow time after 15 minutes of kneading becomes 100 seconds or less. It can be seen that the fluidity is improved.

[Example 2]
Using 1000 g of the cement-based solidifying material shown in Table 1, the amount of water was changed to 500 g, 600 g, 700 g, and 800 g and kneaded (water solidified material ratio = 50%, 60%, 70%, 80%). As the kneading method, a solidifying material slurry was prepared in the same manner as in Example 1. The same evaluation test as in Example 1 was carried out on the prepared cement-based solidifying material slurry.

The test results are shown in Table 3. Sample A2, sample B2, and sample C1 are the same as the sample of Example 1. As shown in Table 3, the tendency of the residue on the sieve and the flow time when passing through the sieve having a 1 mm opening and the sieve having a 2 mm opening was the same as in Example 1.
Comparing sample examples C1 and sample C2, when ^{a cement-based solidifying material (symbol C) with a brain specific surface area of 4460 cm 2} / g was used, the water solidifying material ratio was increased to 70% for 15 minutes of kneading. The subsequent flow time becomes 100 seconds or less, and the fluidity can be improved.
Further, by comparing Sample B2 and Sample B6 to Sample B8, when ^{a cement-based solidifying material (symbol B) having a brain specific surface area of 4890 cm 2} / g was used, the water solidifying material ratio was increased to 80%. The flow time after 15 minutes of kneading becomes 100 seconds or less, and the fluidity can be improved. However, as described above, it should be noted that increasing the ratio of the water solidified material may lead to a decrease in the strength of the improved body.

[Example 3]
1000 g of the cement-based solidifying material shown in Table 1 was used, and 600 g of water was kneaded into the cement-based solidifying material (water solidifying material ratio = 60%). The kneading method was based on the kneading method using the Hobart mixer of Example 1 and the method using a lab stirrer (manufactured by HEIDON, model: BL-1200).
Cement solidifying material having an adjusted Mixing method <br/> temperature 30 to 40 ° C. by a Hobart mixer and water was charged, after 30 seconds mixing at a rotational speed per minute 70 rotates, scraping deposits of the bottom After that, the mixture was further kneaded at a rotation rate of 70 rpm for 30 seconds to prepare a solidifying material slurry.
Kneading method using a lab stirrer A cement-based solidifying material and water whose temperature was adjusted to 30 to 40 ° C. were added and kneaded at a predetermined rotation speed for 60 seconds to prepare a solidifying material slurry. In the lab stirrer, the stirring rotation speed was variable, and the solidifying material slurry was prepared at three levels of 300 rotations, 600 rotations, and 750 rotations per minute, and the mixing time was 60 seconds.

After measuring the kneading temperature of these solidifying material slurries, the fluidity was measured in the same manner as in Example 1. The test results are shown in Table 4. As shown in Table 4, the samples A9, A10, and A11 using the lab stirrer have better fluidity than the sample A1 using the Hobart mixer. The reason for this is that the lab stirrer rotates at a higher speed than the Hobart mixer, and it is considered that the viscosity is lowered by the strong shearing force acting on the slurry. Further, it is considered that the amount of the lumpy substance (the residue of the sieve with a 1 mm opening and the residue of the sieve with a 2 mm opening) is reduced by breaking the lumpy substance in the slurry. Therefore, the viscosity of the slurry and the degree of lumps differ depending on the mixing performance of the mixer used at the construction site. Therefore, the mixer used in the laboratory test kneading may be selected according to the mixer used in the field. That is, when the kneading performance of the mixer is high, it is possible to reduce the fluidity of the slurry without lowering the temperature of the kneaded water or increasing the ratio of the water solidifying material.

[Example 4]
1000 g of the cement-based solidifying material shown in Table 1 was used, and a predetermined amount of a dispersant was added to 600 g of water and kneaded (water solidifying material ratio = 60%). As the dispersant, Diosper K (manufactured by Floric Co., Ltd., polycarboxylic acid type) was used. The amount of the dispersant added was 0.8, 1.5, and 2.2% by mass with respect to the mass of the cement-based solidifying material, and the dispersant was added by mixing with kneading water. The kneading method is the same as in Example 1. Water containing a cement-based solidifying material and a dispersant whose temperature has been adjusted to 30 to 40 ° C. is added to the hovert mixer, and the mixing speed is 70 rpm. After kneading for 30 seconds, the deposits on the bottom of the container were scraped off, and then the mixture was further kneaded at a mixer speed of 70 rpm for 30 seconds to prepare a solidifying material slurry.
After measuring the kneading temperature of this solidifying material slurry, it was passed through a sieve having an opening of 1 mm or 2 mm, and the sieve residue remaining on the sieve was measured. Further, the fluidity was measured in the same manner as in Example 1. The results are shown in Table 5. Sample A1 is the same as Example 1 (Table 1).
As shown in Samples A12 to A14 in Table 5, it can be seen that when the dispersant is added, the sieve residue immediately after kneading is reduced, and therefore the flow time is short and the fluidity is improved.

Claims (4)

Kneading in a slurry with a water solidifying material ratio of 50% to 300% of a cement-based solidifying material containing 30 to 86% by mass of Portland cement clinker, 10 to 50% by mass of blast furnace slag, and 4 to 20% by mass of gypsum (anhydrous plaster equivalent). When the rising temperature is 30 ° C. or higher and the cement is passed through a mesh sieve having a gap of 2 mm, the amount of lumps remaining on the slurry is 3.5% by mass or less of the whole slurry, or / and the gap is 1 mm. A cement-based solidifying material slurry, characterized in that the amount of lumps remaining on the mesh sieve when passed through the mesh sieve is 5.0% by mass or less of the entire slurry. The cement-based solidifying material slurry according to claim 1, wherein the cement-based solidifying material contains limestone and / and fly ash as a small amount of mixed components. A cement-based solidifying material containing 30 to 86% by mass of Portland cement clinker, 10 to 50% by mass of blast furnace slag, and 4 to 20% by mass of gypsum (anhydrous plaster equivalent) is kneaded and mixed with water, and the ratio of the water solidifying material is 50% to 300. In the production method of making a% slurry, the cement-based solidifying material and kneading water having a temperature of 30 to 40 ° C. are used, and either or both of the water-solidifying material ratio and the kneading method are used depending on the material of the cement-based solidifying material. By adjusting, the proportion of lumps remaining on the slurry when the slurry after kneading is passed through a mesh sieve with an opening of 2 mm at a kneading temperature of 30 ° C. or higher is 3.5 mass by mass of the entire slurry. % Or less, and / or a slurry in which the proportion of lumps remaining on the mesh sieve when the slurry is passed through a mesh sieve having an opening of 1 mm is 5.0% by mass or less of the entire slurry. A method for producing a cement-based solidifying material slurry. The method for producing a cement-based solidifying material slurry according to claim 3, wherein a dispersant is added to the kneaded water and used.