JP6198108B2 - Bubble-containing cement composition, method for producing bubble-containing cement composition, and construction method using bubble-containing cement composition - Google Patents

Description

  The present invention relates to a bubble-containing cement composition containing bubbles such as air milk and air mortar, a method for producing a bubble-containing cement composition, and a construction method using the same.

  In recent years, air milk or air mortar in which bubbles are generated by adding a foaming agent to cement milk or mortar has been used. Air milk and air mortar contain air bubbles, so it has better fluidity than cement milk and mortar, and can be filled to every corner of the filling area at the construction site. Compared to the low density and light weight, it has characteristics such as reducing the load on the construction site, so it is used for the cavity filling method and the lightweight embankment method. As a technique related to the bubble-containing cement composition such as air milk and air mortar, patent applications such as Patent Document 1 and Patent Document 2 have been filed.

  In Patent Document 1, a cement milk or cement mortar is formed by kneading a predetermined amount of water and a necessary admixture (in addition, fine aggregate in the case of air mortar) into ultra-high speed cement. A method for producing air milk or air mortar is described in which bubbles are formed by an agent and water, and the cement milk or cement mortar and the bubbles are mixed.

  Patent Document 2 describes a method for producing a bubble mortar (air mortar) by mixing a predetermined amount of a powder foaming agent with cement or the like in advance and adding water to the foamed foam to cause foaming. Patent Document 2 describes that clay minerals and the like are used in combination with a powder foaming agent in order to strengthen bubbles.

  By the way, in the above-mentioned cavity filling method in which a bubble-containing cement composition such as air milk or air mortar is used, the underground cavity portion is filled with the bubble-containing cement composition from the ground via a borehole or the like. An underground cement filling method, which is intended to stabilize the ground by blocking the ground, and a bubble-containing cement composition to the remaining cavity due to leaving the gap between the ground of the tunnel and the sheet pile Filling the void-containing cement composition into the cavity of various places that cannot be backfilled with soil, sand, etc., other than the tunnel cavity filling method that prevents cracking and compressive fracture in the tunnel There is a cavity filling method.

  Among these cavity filling methods, in the underground cavity filling method, water may flow into the hollow portion, and the bubble-containing cement composition must be filled into the hollow portion into which the water has flowed. In other words, in the underground permeable layer, there is an aquifer called an aquifer saturated with groundwater, and if there is a cavity in the environment of such an aquifer, the cavity is inevitable. Therefore, it is necessary to fill the cavity portion into which the water has flowed with the bubble-containing cement composition.

However, since the bubble-containing cement composition such as air milk and air mortar used in Patent Document 1 and Patent Document 2 has a density of about 0.3 to 0.8 t / m ³ and is lighter than water, When filling the cavity portion into which water has flowed as described above, there is a problem that the bubble-containing cement composition floats on the water and cannot be suitably filled into the cavity portion.

Such a problem is not limited to the above-mentioned underground cavity filling method, but is applied to a place where a bubble-containing cement composition such as air milk or air mortar must be filled into holes or gaps in an aquifer environment. In any case, the conventional bubble-containing cement composition has a density of about 0.3 to 0.8 t / m ^3. Then there was a problem that construction was difficult.

  Furthermore, since the bubble-containing composition such as air milk or air mortar contains bubbles in order to improve the fluidity in order to improve the workability such as the above-mentioned cavity filling, naturally, The flow value is larger than that of ordinary cement milk and mortar, but if the flow value is large, the bubble-containing composition may diffuse in water when filling the cavity in the aquifer environment as described above. This has also been a factor in complicating the filling operation into the cavity in an aquifer environment.

JP 2011-73918 A JP 2004-83339 A

  In view of the above-mentioned problems, the present invention avoids the characteristics inherent to the bubble-containing cement composition such as air milk and air mortar, which is excellent in fluidity and workability, as much as possible, as described above. In construction in an aquifer environment, when filling a void-containing cement composition into a cavity such as a hole or a gap, the bubble-containing cement composition does not float in water and is less likely to diffuse in water. It is an object of the present invention to provide a bubble-containing cement composition capable of suitably filling a void-containing cement composition into a cavity portion, a method for producing the bubble-containing cement composition, and a construction method using the bubble-containing cement composition. .

The inventors of the present invention set the specific content of the rapid setting agent and the clay mineral in the bubble-containing cement composition, and the density of the bubble-containing cement composition is 1.0 t / m ³ or more. In the case where the void-containing cement composition is filled in the cavity portion in an aquifer environment, while maintaining the properties inherent to the bubble-containing cement composition, which is excellent in workability and excellent workability, as much as possible. The present invention has been completed by finding that the bubble-containing cement composition does not float in water and does not diffuse in water and can be suitably filled with the bubble-containing cement composition in the cavity. It came to do.

The present invention has been made to solve such problems. The bubble-containing cement composition of the present invention is formed by mixing cement, a foaming agent, a clay mineral, and a quick setting agent. The mixed powder and water are kneaded , the foaming agent is sodium alpha olefin sulfonate, the quick setting agent is sodium aluminate, and the quick setting agent is the total amount of the composition. 0.2 mass% to 0.4 mass% and the clay mineral is contained in an amount of 2.5 mass% to 15.0 mass% with respect to the total amount of the composition, and the density is 1.0 t / m ³ or more and 1.4 t / m ³ or less.

In addition, the method for producing the aerated cement composition of the present invention is a mixture formed by mixing cement, sodium alpha olefin sulfonate as a foaming agent, clay mineral, and sodium aluminate as a quick setting agent. Powder and water, the quick setting agent is contained in an amount of 0.2% by mass to 0.4% by mass with respect to the total amount of the composition, and the clay mineral is 2.5% by mass with respect to the total amount of the composition. % To 15.0% by mass and the density is adjusted to 1.0 t / m ³ or more and 1.4 t / m ³ or less.

Furthermore, the construction method using the foam-containing cement composition of the present invention is formed by mixing cement, sodium alpha olefin sulfonate as a foaming agent, clay mineral, and sodium aluminate as a quick setting agent. 1. The mixed powder and water are contained in an amount of 0.2 mass% to 0.4 mass% with respect to the total amount of the composition and the clay mineral is 2. A bubble-containing cement composition is obtained by adjusting the density so as to be contained in an amount of 5% by mass or more and 15.0% by mass or less and having a density of 1.0 t / m ³ or more and 1.4 t / m ³ or less. The construction is performed using the composition.

In the present invention, the rapid setting agent is contained in an amount of 0.2% by mass to 0.4% by mass with respect to the total amount of the bubble-containing composition, and the clay mineral is 2.5% by mass or more with respect to the total amount of the composition. 15.0% by mass or less and the density is 1.0 t / m ³ or more, so that the inherent properties of the bubble-containing cement composition, which is excellent in fluidity and workability, should not be lost as much as possible. On the other hand, when the bubble-containing cement composition of the present invention is further filled in the cavity portion in an aquifer environment, the bubble-containing cement composition does not float on water and it becomes difficult to fill the cavity portion. .

  Further, the rapid setting agent is contained in an amount of 0.2% by mass to 0.4% by mass with respect to the total amount of the bubble-containing composition, and the clay mineral is 2.5% by mass to 15.0% with respect to the total amount of the composition. By containing less than mass%, the flow value of the bubble-containing composition with originally good fluidity is maintained above a certain level, but the flow value becomes smaller than the flow value of the conventional bubble-containing composition. When filling the void-containing composition into the cavity in the aquifer environment as described above, the risk of the bubble-containing composition diffusing in water as in the prior art is reduced.

On the other hand, since the density of the bubble-containing cement composition of the present invention is 1.4 t / m ³ or less, it is difficult to separate materials.

  The bubble-containing cement composition referred to in the present invention means a cement composition containing bubbles formed by a foaming agent, and includes, for example, air mortar and air milk.

  According to the present invention, in the construction under the aquifer environment, while avoiding as much as possible the characteristics inherent to the bubble-containing cement composition such as air milk and air mortar, which has good fluidity and excellent workability. When filling a void-containing cement composition into a cavity such as a hole or a gap, the bubble-containing cement composition does not float in water and is less likely to diffuse in water. It is possible to provide a bubble-containing cement composition that can be suitably filled in a part, a method for producing the bubble-containing cement composition, and a construction method using the bubble-containing cement composition.

  Hereinafter, embodiments of the present invention will be described. First, an embodiment of the bubble-containing cement composition of the present invention will be described.

The bubble-containing cement composition of the present embodiment includes cement, a foaming agent, a clay mineral, a quick setting agent, and water, and the quick setting agent is 0.2 mass relative to the total amount of the composition. % to 0.4 wt% or less contained and the clay mineral contains 15.0 wt% 2.5 wt% or more, based on the total amount of the composition, density 1.0 t / m ³ or more 1.4t / m ³ or less.

  The bubble-containing cement composition refers to a cement composition containing bubbles formed by a foaming agent. For example, air milk or air mortar containing bubbles formed by a foaming agent in a cement slurry containing cement and water. Etc.

  The cement is not particularly limited as long as it is a publicly known cement. Portland cement such as blast furnace cement, fly ash cement, silica cement and the like mixed cement; ultrafast cement, alumina cement and the like. Among them, blast furnace cement, ordinary cement, and the like are preferable because the pot life can be easily adjusted and the cost is low.

  As the foaming agent, for example, an alpha olefin sulfonic acid-based foaming agent is used. By using an alpha olefin sulfonic acid-based foaming agent, the bubbles in the foam-containing cement composition can be stably maintained, and the foaming agent and the cement composition components other than the foaming agent are mixed in advance. It can be conveyed to the construction site in the state of the aerated bubble-containing cement composition. Furthermore, a desired strength is expressed in a relatively short time, and the construction site can be used in a relatively early stage after construction.

  Examples of the alpha olefin sulfonic acid foaming agent include sodium alpha olefin sulfonate powder. As such a foaming agent, for example, trade name “Lipolane PJ-400” manufactured by Lion Corporation, trade name “Lipolane PB-800” manufactured by Lion Corporation, and the like can be used. The foaming agent is not limited to being a powder, but in the case of a powder foaming agent, it can be mixed with a powder component such as cement in advance and is easy to manufacture. Therefore, it is preferable. Further, the foaming agent may contain components other than the foaming component such as sodium alpha olefin sulfonate.

  Examples of clay minerals include layered clay minerals, fibrous clay minerals, amorphous clay minerals, silica minerals, feldspar, zeolite, dolomite, and fired products thereof, and mixtures of two or more thereof. Especially, the clay mineral which is 1 or more types selected from the group which consists of layered clay mineral, fibrous clay mineral, and these baked products is preferable. One or more clay minerals selected from the group consisting of such layered clay minerals, fibrous clay minerals, amorphous clay minerals, and fired products thereof can make the bubble stability better, and This is because a desired strength can be obtained in a shorter time after the construction. Examples of the layered clay mineral include kaolin mineral, serpentine and related minerals, pyrophyllite, talc, mica clay mineral, chlorite, vermiculite, smectite, bentonite and the like. Examples of the fibrous clay mineral include sepiolite and attapulgite. Examples of the calcined product of clay mineral include metakaolin, which is a calcined product of kaolin, and metahalloysite, which is a calcined product of halloysite.

  Among the clay minerals, bentonite, attapulgite, and the like are preferable from the viewpoint of improving the stability of the bubbles and from the viewpoint that a desired strength can be easily obtained in a relatively short time.

  The clay mineral preferably has a swelling power of 15 ml / 2 g or more and 50 ml / 2 g or less. When the swelling power of the clay mineral is in the above range, the stability of the bubbles becomes better. In addition, the said swelling power means the swelling power measured based on the method prescribed | regulated to the standard test method (JBAS-104) of Japan Bentonite Industry Association.

As the quick setting agent, for example, quick setting agents such as alkali aluminate, calcium aluminate and calcium sulfoaluminate are used. Among them, it is preferable to use an alkali aluminate, and it is particularly preferable to use sodium aluminate. By using sodium aluminate, air bubbles and air mortar are filled with the bubble-containing cement composition in the cavity under the aquifer environment while maintaining the bubbles necessary to exhibit the function of the bubble-containing cement composition. There is an advantage that the work can be suitably performed.
Further, the quick setting agent may contain components other than the quick setting component such as sodium aluminate. Here, when the quick setting agent contains components other than the quick setting component together with the quick setting component, the content (% by mass) of the quick setting agent with respect to the total amount of the composition is that of the quick setting component with respect to the total amount of the composition. It means content (mass%). Examples of the quick setting component include one or more selected from the group of sodium aluminate, aluminum sulfate, and sodium silicate.

In the foam-containing cement composition of the present embodiment, as described above, the content of the quick setting agent with respect to the total amount of the composition is 0.2% by mass or more and 0.4% by mass or less, and the content of the clay mineral Is 2.5% by mass or more and 15.0% by mass or less with respect to the total amount of the composition. When the quick setting agent is less than 0.2% by mass with respect to the total amount of the composition, the density of the bubble-containing composition becomes less than 1.0 t / m ³ and the flow value becomes too large, This is because there is a possibility that the work of filling the hollow portion with the bubble-containing cement composition may not be suitably performed. On the other hand, when the quick setting agent exceeds 0.4% by mass with respect to the total amount of the composition, the flow value may be too small to obtain the fluidity necessary for functioning as a bubble-containing composition. Because there is. From such a viewpoint, the content of the quick setting agent with respect to the total amount of the bubble-containing cement composition is more preferably 0.25% by mass or more and 0.4% by mass or less.

  Further, if the clay mineral is less than 2.5% by mass relative to the total amount of the composition, the density may be too high, and if it exceeds 15.0% by mass, kneading may not be possible. From such a viewpoint, the content of the clay mineral with respect to the total amount of the bubble-containing cement composition is more preferably 5.0% by mass or more and 10.0% by mass or less.

The density of the bubble-containing cement composition of the present embodiment is 1.0 t / m ³ or more and 1.4 t / m ³ or less. When the density is 1.0 t / m ³ or more, when the bubble-containing cement composition is filled in the cavity portion in the aquifer environment, the bubble-containing cement composition does not float on water. The operation | work which fills a cavity part with a containing cement composition can be performed more easily. On the other hand, if the density is 1.4 t / m ³ or less, the possibility of material separation is reduced.

  Moreover, it is preferable that the flow value of the bubble-containing cement composition of this embodiment is 140 mm or less by the measurement according to the flow test of the NEXCO test method 313 mentioned later, for example. If it exceeds 140 mm, there is a risk of spreading in the water when filling the void-containing cement composition in the aquifer environment, and as a result, filling the void-containing cement composition into the hollow portion may be complicated. Because there is. In addition, it is preferable that the flow value of a bubble containing cement composition is 80 mm or more from a viewpoint of maintaining the fluidity | liquidity required to make it function as air milk, air mortar, etc. originally.

Furthermore, it is preferable that content of the foaming agent with respect to the total amount of a composition is 0.09 mass% or more and 0.4 mass% or less. When the content of the foaming agent relative to the total amount of the composition is less than 0.09% by mass, there is a possibility that bubbles necessary for functioning as a bubble-containing cement composition such as air milk or air mortar are not retained in the composition. On the other hand, when it exceeds 0.4 mass%, the density of the bubble-containing composition becomes less than 1.0 t / m ³ , and when the work of filling the void-containing cement composition into the cavity portion in the aquifer environment is performed. When the bubble-containing cement composition floats in water, and the flow value of the bubble-containing cement composition increases and the bubble-containing composition is filled in the cavity in the aquifer environment, the bubble-containing composition diffuses in water. It is because there is a possibility of doing.
Here, the content (% by mass) with respect to the total amount of the foaming agent composition is such that, for example, components other than the foaming component such as sodium alpha olefin sulfonate are contained in the foaming agent together with the foaming component. Means the content (mass%) of the foaming component relative to the total amount of the composition.

Furthermore, the cement content relative to the total amount of the composition is preferably 35% by mass or more and 60% by mass or less. This is because if it is less than 35% by mass, the density may be less than 1.0 t / m ³ , while if it exceeds 60% by mass, kneading may not be possible. From this viewpoint, the content is more preferably 40% by mass or more and 50% by mass or less.

  Furthermore, it is preferable that content of the water with respect to the total amount of a composition is 33 to 55 mass%. If the amount is less than 33% by mass, kneading may not be possible, whereas if it exceeds 55% by mass, the density may be low. From this viewpoint, the content is more preferably 40% by mass or more and 50% by mass or less.

  The cement composition of this embodiment may further contain a retarder, a water reducing agent, and the like. Moreover, when obtaining air mortar as a bubble containing cement composition, the aggregate may be further included.

  Next, an embodiment of a method for producing a bubble-containing cement composition of the present invention will be described.

  In the method for producing a bubble-containing cement composition of the present embodiment, cement, a foaming agent, a clay mineral, a quick setting agent, and water are added to the total amount of the composition. 2 mass% or more and 0.4 mass% or less are contained, and it mixes so that the said clay mineral may be contained 2.5 mass% or more and 15.0 mass% or less with respect to the total amount of a composition.

  Specifically, when the foaming agent is a powder, cement as a powder component and the foaming agent are mixed to form a mixed powder, and predetermined water is added to the mixed powder and kneaded. And a method for obtaining a bubble-containing cement composition. Or the method of obtaining the bubble-containing cement composition by mixing and knead | mixing each component of the said powder component and water at once is mentioned. In any method, bubbles are generated by dissolving the foaming agent in water, and the bubbles are uniformly mixed in the slurry-like cement composition by kneading, thereby containing bubbles such as air milk or air mortar. A cement composition is produced. The kneading can be performed, for example, by putting each material in a container of several liters to several tens of liters and kneading with a hand mixer or the like.

  In addition, a filler, an aggregate (in the case of air mortar) or the like may be further added as the powder component, and a retarder, a water reducing agent or the like may be further added to water as the liquid component.

When the filler is used, it is preferable to use a filler that has not been dried using heavy oil. Examples of the filler include silica powder and silica sand powder (in the case of air mortar), and these are preferably fine powder. By using a filler to which sulfur oxides and nitrogen oxides are not attached, the stability of bubbles can be further improved. This is because sulfur oxide (SO _x ) and nitrogen oxide (NO _x ) generated during drying are considered to be one of the factors that crush bubbles.

  Next, a construction method for performing construction using the bubble-containing cement composition produced as described above at the construction site will be described. In the construction method of the cement composition of the present embodiment, the cement, the foaming agent, the clay mineral, the quick setting agent, and the water are added in an amount of 0.2% by mass based on the total amount of the quick setting agent. The foam-containing cement composition is obtained by mixing so that the clay mineral is contained in an amount of not less than 0.4% by mass and the clay mineral is not less than 2.5% by mass and not more than 15.0% by mass with respect to the total amount of the composition. Construction is performed using the bubble-containing cement composition.

In this case, in the produced bubble-containing cement composition, the quick setting agent is contained in an amount of 0.2% by mass to 0.4% by mass with respect to the total amount of the composition, and the clay mineral is based on the total amount of the composition. 2.5 wt% to 15.0 wt%, and 1.0 t / m ³ or more and 1.4 t / m ³ or less. When it is transported to the construction site and the bubble-containing cement composition is filled in the cavity at such a construction site, the fluidity is good and the workability is excellent, and the load on the construction site can be reduced. In the case where the bubble-containing cement composition is filled in the cavity portion in the aquifer environment while avoiding the characteristics inherent to the bubble-containing cement composition such as air milk and air mortar as much as possible, the bubble-containing cement composition is Like floating in the water There is nothing.

  In addition, while the flow value of the bubble-containing composition that is inherently good in fluidity is maintained above a certain level, the flow value is smaller than the flow value of the conventional bubble-containing composition, and the above-described aquifer environment When filling the cavity portion with the bubble-containing composition below, the risk of the bubble-containing composition diffusing in water as in the conventional case is reduced.

  Furthermore, in the construction method of the foam-containing cement composition of the present embodiment, the foam-containing cement composition is produced in advance by a production method as described above at a location away from the construction site such as a factory, and then transported to the construction site. And it can be used as a bubble-containing cement composition at a construction site.

  When the foam-containing cement composition is transported to the construction site as described above, if the clay-containing mineral is contained in the foam-containing cement composition, the foam is easily maintained in the composition, such as cement milk or cement mortar. Since the slurry-like cement composition and the foaming agent can be conveyed in a state of being mixed in advance without being separately conveyed, the conveyance cost can also be suppressed. Furthermore, since only the necessary amount of the mixed material needs to be manufactured and transported prior to transportation, material loss is small, which is advantageous in terms of cost. In addition, at the construction site, it is not necessary to mix the slurry-like cement composition and the foaming agent conveyed by different conveyance media with a dedicated device, and thus the equipment can be downsized at the construction site.

Although the method of conveying the said bubble containing cement composition to a construction site is not specifically limited, For example, using conveyance vehicles, such as a mixer vehicle and a mobile vehicle, is mentioned. In the case of a construction scale of several L to several tens of m ³ , it is preferable to use a mobile vehicle or a mixer truck, and in the case of a construction scale of several tens of m ³ or more, it is preferable to use a mixer truck. Or you may convey using conveyance apparatuses other than conveyance vehicles, such as a transfer pipe connected from the manufacturing place to the construction site.

  The bubble-containing cement composition conveyed to the construction site may be applied at the construction site as it is, or may be applied after further adding water or the like at the construction site.

Thus, since the manufacturing method of the cement composition of this embodiment, a bubble containing cement composition, and these construction methods do not require a large installation in a construction place, a construction amount is small (for example, less than 100 m < ³ >). This is particularly advantageous.

  In addition, although this embodiment is as above, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

(Contains cement composition)
Examples 1 to 11 and Comparative Examples 1 to 14 having the contents shown in Table 1 were prepared as cement compositions for cement milk used in this example. In Table 1, the unit of the content of each material of the cement composition is g. The value in parentheses for the content of clay mineral and quick-set agent is mass%. Further details of each material used are as follows.

(material)
Cement: Blast furnace cement (Brand name "Blast furnace cement type B", manufactured by Sumitomo Osaka Cement Co., Ltd.)
Clay mineral: Bentonite (Hojoon Super Clay: swelling power 30ml / 2g)
Powder foaming agent: sodium alpha olefin sulfonate (trade name “Lipolane PB-800”: manufactured by Lion Corporation)
Quick setting agent: Sodium aluminate (trade name “Sodium aluminate”, manufactured by Taiyo Co., Ltd.)

(Production method)
First, as a powder component, cement, clay mineral, powder foaming agent, and quick setting agent are put in a container with a capacity of 5 L, and two rubber stoppers are put and mixed by shaking. Each amount of water described in 1 was added and kneaded at 1300 rpm for 2 minutes using a hand mixer (trade name “UT-1305”, manufactured by Makita) to obtain air milk.

(Evaluation method)
About each Example and the comparative example, the density, the air content, the flow value, the property, and the compressive strength were measured as follows.
<< Density / Air volume >>
The total weight and volume of each air milk 2 minutes after kneading were measured.
The density was determined from the total weight and volume. The volume was calculated from the density of each raw material powder and water. Furthermore, the amount of air was determined from the density and weight.
<Flow value>
The flow value was measured according to the flow test described in NEXCO test method 313.
《Compressive strength》
The compressive strength was determined by measuring the compressive strength at 1 day, 7 days and 28 days of age using a method according to the uniaxial compression test method of soil described in JIS A1216.

<Properties>
Air milk immediately after kneading was filled in a bleeding bag, and the properties after 3 hours were visually observed to evaluate the presence or absence of defoaming, separation, and accumulation of water at the bottom.

These results are shown in Tables 2 and 3. In Table 2, the unit of density is t / m ³ , the unit of flow value is mm, the unit of total weight is g, the unit of volume is cm ³ , and the unit of air amount is cm ³ . In Table 3, the unit of compressive strength is kN / m ² .

(Evaluation results)
As shown in Table 1 and Table 2, the content with respect to the total amount of the composition of the quick setting agent is 0.2% by mass or more and 0.4% by mass or less, and the content with respect to the total amount of the clay mineral composition is 2.5%. The density of each of the air milks of Examples 1 to 11 that is 1% by mass or more and 15.0% by mass or less was 1.0 t / m ³ or more and 1.4 t / m ³ or less.
In contrast, the density of Eamiruku of Comparative Example 1 and Comparative Example 2 also clay mineral also rapid setting agent is not contained, either each 0.627t / m ³ and 0.743t / m ³ 1.0t / It was less than m ³ .
Each of the clay minerals is 100 g (5.0% by mass with respect to the total weight of the composition) and 50 g (2.5% by mass with respect to the total weight of the composition). density of Eamiruku of Comparative examples 3 and 4 were both less than 1.0 t / m ^3, respectively 0.682t / m ³ and 0.717t / m ^3.
Furthermore, 2.0 g (0.1% by mass with respect to the total weight of the composition) and 5.0 g (0.25% by mass with respect to the total weight of the composition) are contained in each of the quick-setting agents. There density of Eamiruku of Comparative examples 5 and 6 that are not contained, respectively 0.735t / m ³ and 0.877t / m ^3, Comparative example 6 was higher density than Comparative examples 1 to 4 and Comparative examples Both 5 and 6 were less than 1.0 t / m ³ .
Further, 100 g of clay mineral (5.0% by mass with respect to the total weight of the composition) and the same amount as in Examples 4 to 11 above, but each 1.0 g of quick setting agent (total of the composition) 0.05% by weight) and 2.0 g (0.1% by weight with respect to the total weight of the composition), less than 0.2% by weight, less than the above Examples 4 to 11 density of Eamiruku of Comparative examples 7 and 8 is the respectively 0.832t / m ³ and 0.800t / m ^3, but the density was higher than Comparative examples 1 to 4, there is less than 1.0 t / m ³ It was.
Further, 5.0 g (0.25% by mass with respect to the total weight of the composition) of the quick setting agent is contained in the same amount as in Examples 1 to 3 and 6 to 11, but 25 g of clay mineral ( 1.2 mass% based on the total weight of the composition), and the density of the air milk of Comparative Example 10 that is less than 2.5 mass% with a content less than those of Examples 4 to 11 is 1.491 t / The m ³ exceeded 1.4 t / m ³ .
Further, 100 g of clay mineral (5.0 mass% with respect to the total weight of the composition) and the same amount as in Examples 4 to 11 above, but 10.0 g of quick setting agent (total weight of the composition) The air milk of Comparative Example 9 having a content higher than that of Examples 1 to 11 and exceeding 0.4% by mass cannot be kneaded, and has a density and a flow value. It could not be measured.
Further, 5.0 g (0.25% by mass with respect to the total weight of the composition) of the quick setting agent is contained in the same amount as in Examples 1 to 3 and 6 to 11, but 350 g of clay mineral ( The air milk of Comparative Example 11, which is 17.4% by mass based on the total weight of the composition and more than the above Examples 1 to 11 and exceeds 15.0% by mass, is also incapable of kneading and has a density. And the flow value could not be measured.
The air milk of Comparative Examples 12 to 14 contains 5.0 g (0.25% by mass with respect to the total weight of the composition) of the quick setting agent, and 100 g of clay mineral (5.0% with respect to the total weight of the composition). %) And the respective contents are the same as those in Examples 6 to 11, but as described above, in Comparative Examples 12 and 13, the density is slightly lower than 1.0 t / m ^3. In 14, the density exceeded 1.4 t / m ³ . In Comparative Example 12, the content of water is 1200 g (56.8% by mass based on the total weight of the composition), which is larger than Examples 1 to 11, and in Comparative Example 13, the content of the foaming agent is 10. 0 g (0.5% by mass with respect to the total weight of the composition), which is larger than Examples 1 to 11, and in Comparative Example 14, the content of the foaming agent is 2.0 g (with respect to the total weight of the composition). 0.1 mass%) and less than Examples 1 to 11.

  Furthermore, the flow values of the air milks of Examples 1 to 8 were about 86 to 145 mm, and all were smaller than Comparative Examples 1 to 8 and 10 of about 173 to 315 mm.

From the above, a predetermined amount of clay mineral and rapid setting agent (content with respect to the total amount of the clay mineral composition is 2.5% by mass or more and 15.0% by mass or less, content with respect to the total amount of the quick setting agent composition) It was found that the air milk density was 1.0 t / m ³ or more and 1.4 t / m ³ or less, and the flow value was also reduced. Therefore, if the air milk of Examples 1 to 11 is used for construction in an aquifer environment, it is possible to suitably fill the cavity such as holes and gaps, and when filling the cavity with the bubble-containing composition. It is considered that the bubble-containing composition is less likely to diffuse in water.

  Next, in the visual property observation, in Comparative Examples 1, 4, and 10, the bubbles disappeared and decreased, and there were no uniform bubbles. Furthermore, separation of cement milk by defoaming occurred. Further, in the property observation of Comparative Example 3, a water pool due to separation occurred. Furthermore, the air milk of Comparative Examples 9 and 11 could not be kneaded. On the other hand, in the air milks of Examples 1 to 11, such defoaming, separation, and water pool at the bottom were not recognized, and kneading was not impossible.

Furthermore, the air milk of Examples 1, 4, and 8 had a compressive strength of about 10 to 60 kN / m ² at a material age of 1 day, but exceeded 1400 kN / m ² at a material age of 7 days, and at a material age of 28 days. It was over 3000 kN / m ² . The Eamiruku examples 2, 3 and 5 to 7, the compressive strength is above the 100 kN / m ² in one day the age, are over 2000 kN / m ² at an age of 7 days, at age of 28 days It was over 3500 kN / m ² .

  On the other hand, the air milk of Comparative Examples 1, 2, 9 to 11 could not measure the compressive strength at any age of 1 day, 7 days, and 28 days. The air milk of Comparative Example 5 was able to measure the compressive strength at 7 days and 28 days of age, and the Air Milk of Comparative Examples 3, 4, 6 to 8 was able to measure the compressive strength of 1 day, 7 days and 28 days of age. In any case, the compressive strength was inferior to the air milk of Examples 1 to 8. In Examples 9 to 11 and Comparative Examples 12 and 13, the compressive strength was not measured.

As described above, the air milks of Examples 1 to 11 have a density of 1.0 t / m ³ or more, the flow value is smaller than that of the air milks of the respective comparative examples, and the air milk is sufficiently contained, or the bubble omission is suppressed. Furthermore, it was found that the uniformity of bubbles was high. Moreover, it turned out that the air milk of Examples 1-8 is higher than the air milk of each comparative example.

Claims (3)

Cement, a foaming agent, a clay mineral, a mixed powder formed by mixing a quick setting agent, and water are kneaded and formed.
The foaming agent is sodium alpha olefin sulfonate;
The quick setting agent is sodium aluminate;
The quick setting agent is contained in an amount of 0.2% by mass to 0.4% by mass with respect to the total amount of the composition, and the clay mineral is 2.5% by mass to 15.0% by mass with respect to the total amount of the composition. Included,
A bubble-containing cement composition having a density of 1.0 t / m ³ or more and 1.4 t / m ³ or less. The quick setting agent is composed of cement, a mixed powder formed by mixing alpha olefin sulfonate sodium as a foaming agent, clay mineral and sodium aluminate as a quick setting agent, and water. The clay mineral is contained in an amount of not less than 0.2% by mass and not more than 0.4% by mass with respect to the total amount of the object, and the clay mineral is not less than 2.5% by mass and not more than 15.0% by mass with respect to the total amount of the composition. method for producing .0t / ^{m 3} or more 1.4t / ^{m 3} or less and so as to prepare for aerated cement composition. The quick setting agent is composed of cement, a mixed powder formed by mixing alpha olefin sulfonate sodium as a foaming agent, clay mineral and sodium aluminate as a quick setting agent, and water. The clay mineral is contained in an amount of not less than 0.2% by mass and not more than 0.4% by mass with respect to the total amount of the object, and the clay mineral is not less than 2.5% by mass and not more than 15.0% by mass with respect to the total amount of the composition. to obtain a bubble-containing cement composition be prepared such that .0t / m ³ or more 1.4t / m ³ or less, using a bubble-containing cement composition to perform construction by using the bubble-containing cement composition Construction method.