JP6011931B2 - CEMENT COMPOSITION, MANUFACTURING METHOD FOR AIR-CONTAINING CEMENT COMPOSITION, AND CONSTRUCTION METHOD USING AIR-CONTAINING CEMENT COMPOSITION - Google Patents

Description

  The present invention relates to a cement composition containing a foaming agent, a method for producing a bubble-containing cement composition, and a construction method using the same.

  Bubble-containing cement compositions such as air milk and air mortar are used for cavity filling, light weight embankment, disaster recovery work, and the like (for example, Patent Document 1). In recent years, an air mortar with an underwater non-separation performance has been developed as an intermediate material for pipe correction.

  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.

Moreover, the powder foaming agent for cement mortar which can be mixed with a cement mortar previously is proposed (for example, patent document 2).
Patent Document 2 describes a method for producing a bubble mortar (air mortar) by previously mixing a predetermined amount of a powder foaming agent with cement or the like, and adding water to the resulting 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.

  However, the air milk or air mortar of Patent Document 1 needs to manufacture and transport cement milk or cement mortar and air bubbles separately for construction, and mix them on site immediately before construction. It is necessary and the construction work is complicated.

  In the air mortar described in Patent Document 2, since the foaming agent and cement mortar can be mixed in advance, the complexity of the construction work as described above can be eliminated, but the powder foaming agent and clay mineral are used in combination. However, the stability of the bubbles is not necessarily good enough. In particular, when the foaming agent and cement mortar are mixed in advance and then transported to the construction site, the amount of bubbles is reduced when air bubbles are removed from the air mortar when installed at the construction site, or There is a risk of air bubbles becoming uneven. Thus, when air mortar in which the amount of bubbles is reduced or non-uniform is applied, it is not possible to produce a hardened body with the volume designed at the application location. Furthermore, since the air mortar described in Patent Document 2 takes a relatively long time to obtain a desired strength after construction, it is not suitable for construction in a construction location that is required to start service in an early stage.

JP 2011-73918 A JP 2004-83339 A

  In view of the above-mentioned problems, the present invention provides a cement composition and a foam-containing cement composition that have good construction stability due to good bubble stability and can obtain a desired strength in a relatively short period of time. It is an object of the present invention to provide a method and a construction method using the bubble-containing cement composition.

  By using a specific foaming agent and a specific amount of clay mineral in combination, the inventors have extremely good stability of the bubbles in the cement composition and have a desired strength in a relatively short time. The inventors have found that expression can be obtained and have completed the present invention.

Method of manufacturing a bubble-containing cement composition of the present invention, cement and clay mineral is a powder component, an alpha olefin sulfonate-based powder foaming agent, the total amount of the clay mineral and the cement wherein comprising a step of clay minerals to form a mixed powder by mixing a so that contains 25 wt% or less than 10 wt%, a step of kneading by adding water to the mixed powder, a.

  The present invention includes a cement, an alpha olefin sulfonic acid-based foaming agent, and a clay mineral, and the clay mineral is 10% by mass to 25% by mass with respect to the total amount of the cement and the clay mineral. By being contained, it is possible to improve the stability of the bubbles when the bubble-containing cement composition is used. In addition, since the bubbles in the bubble-containing cement composition can be stably maintained, it is transported to the construction site in the state of a bubble-containing cement composition in which a foaming agent and a cement composition component other than the foaming agent are mixed in advance. be able to. Furthermore, since the desired strength is expressed in a relatively short time, the use of the construction site can be started relatively early after the construction.

  As one aspect of the present invention, the clay mineral may be one or more selected from the group consisting of a layered clay mineral, a fibrous clay mineral, an amorphous clay mineral, and a fired product thereof.

  When the clay mineral is at least one selected from the group consisting of layered clay minerals, fibrous clay minerals, amorphous clay minerals, and fired products thereof, the stability of the bubbles is improved. The desired strength can be obtained in a shorter time after the construction.

This invention which concerns on the manufacturing method of a bubble containing cement composition is 0.03 mass% or more and 1 mass% or less of the said powder foaming agent with respect to the total amount of the said cement and the said clay mineral. You may mix so that it may be included.

  The bubble-containing cement composition referred to in the present invention means a cement composition containing bubbles formed by a foaming agent.

The present invention relating to a construction method using a cement composition comprises a cement and clay mineral as powder components, and an alpha olefin sulfonic acid-based powder foaming agent, based on the total amount of the cement and the clay mineral. The clay mineral is mixed so that it is contained in an amount of 10% by mass or more and 25% by mass or less to form a mixed powder, and water is added to the mixed powder to knead to obtain a foam-containing cement composition. The bubble-containing cement composition is transported to the construction site for construction.

  According to the present invention relating to the construction method using the cement composition, since the construction is performed using the bubble-containing cement composition, the cured body according to the volume designed at the construction site because the stability of the bubbles is good. It is possible to suppress the deterioration of the construction quality, such as inability to manufacture. In addition, since a desired strength can be obtained in a relatively short time, in-service use can be started at an early stage. Furthermore, since the bubble-containing cement composition is obtained in advance, and the bubble-containing cement composition is transported to the construction site for construction, there is no need to perform the work of mixing the bubble-containing cement composition at the construction site. The construction work can be done easily.

  ADVANTAGE OF THE INVENTION According to this invention, the construction quality becomes favorable because the stability of the air bubbles is good, and the desired strength can be obtained in a relatively short period of time, the method for producing the air bubble-containing cement composition, and the air bubble containing A construction method using the cement composition can be provided.

An embodiment of the present invention will be described.
First, an embodiment of the cement composition of the present invention will be described.
The cement composition of the present embodiment includes cement, an alpha olefin sulfonic acid-based foaming agent, and a clay mineral, and the clay mineral is 10% by mass with respect to the total amount of the cement and the clay mineral. The cement composition is contained in an amount of 25% by mass or less.

  The cement composition of the present embodiment is a cement composition for a bubble-containing cement composition. The bubble-containing cement composition refers to a cement composition containing bubbles formed by a foaming agent. For example, a bubble formed by a foaming agent is contained in a cement slurry containing at least cement and water. Air milk, air mortar and the like.

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.

Examples of the alpha olefin sulfonic acid-based foaming agent include powders containing sodium alpha olefin sulfonate as a main component (for example, containing 35% by mass or more). 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.

The blending amount of the alpha olefin sulfonic acid foaming agent is, for example, 0.03% by mass or more and 1% by mass or less, preferably 0.05% by mass or more and 0% by mass with respect to the total amount of cement and clay mineral. 0.8 mass% or less, more preferably 0.2 mass% or more and 0.6 mass% or less.
When the blending amount of the alpha olefin sulfonic acid foaming agent is within such a range, a sufficient amount of bubbles can be obtained, and at the same time, a desired strength can be obtained in a relatively short time when a cured product is obtained. It is done.

Examples of clay minerals include layered clay minerals, fibrous clay minerals, amorphous clay minerals, silica minerals, feldspars, zeolites, dolomite, and the like, and fired products of these clay minerals, 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.
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 Japanese bentonite industry association standard test method (JBAS-104).

  The clay mineral is contained in an amount of 10% by mass to 25% by mass, preferably 15% by mass to 22% by mass with respect to the total amount of the cement and the clay mineral.

  When the blending amount of the clay mineral is within the above range, the bubbles can be stably maintained in the cement composition after foaming. Moreover, there is no possibility of suppressing foaming of the foaming agent, and a cured product having a volume as designed can be obtained.

  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 the method for producing the bubble-containing cement composition of the present invention will be described.

  The method for producing a foam-containing cement composition of the present embodiment includes a cement, an alpha-olefin sulfonic acid foaming agent, a clay mineral, and water with respect to a total amount of the cement and the clay mineral. It mixes so that clay mineral may contain 10 mass% or more and 25 mass% or less.

Specifically, when the powder component cement and clay mineral and the alpha olefin sulfonic acid-based foaming agent are powders, they are mixed to form a powder mixture. Examples thereof include a method of adding a predetermined water and kneading to obtain a foam-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.

The amount of water to be blended at the time of kneading can be appropriately adjusted according to the amount of foaming agent and the like, for example, 60% by mass to 120% by mass with respect to the total amount of cement and clay mineral. Preferably, it is about 80% by mass or more and about 100% by mass.
When the amount of water is within such a range, the foaming agent can be sufficiently foamed to contain a sufficient amount of bubbles.

  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 clay, the alpha olefin sulfonic acid foaming agent, the clay mineral, and water are added to the clay mineral with respect to the total amount of the cement and the clay mineral. Is mixed so as to be contained in an amount of 10% by mass or more and 25% by mass or less, and a bubble-containing cement composition is obtained, and the bubble-containing cement composition is transported to a construction site for construction.

  Specifically, in the construction method of the cement composition of the present embodiment, the bubble-containing cement composition is produced in advance by a production method as described above at a place away from the construction site such as a factory, and then the construction site. It can be transported and used as a blended product 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.

The cement composition of the present embodiment includes cement, an alpha olefin sulfonic acid-based foaming agent, and a clay mineral, and the clay mineral is 10% by mass with respect to the total amount of the cement and the clay mineral. By containing 25% by mass or less, when the foam-containing cement composition is used, it is possible to effectively suppress the reduction of bubbles, and it is possible to effectively suppress the loss of bubbles, and Since the non-uniformity can be effectively suppressed, the stability of the bubbles can be improved.
For this reason, even if bubbles are foamed with a foaming agent in advance before arriving at the construction site, because the stability of the bubbles is high, it can be used as a blended product at the construction site. This eliminates the need for complicated work of mixing these components, and makes the construction work easy.

In addition, since the slurry-like cement composition such as cement milk or cement mortar and the foaming agent can be conveyed in advance without being separately conveyed, the conveyance cost can 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.
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.

(Cement composition)
Examples 1 to 9 and Comparative Examples 1 to 4 having the blending amounts shown in Table 1 were prepared as cement compositions for cement milk used in this example.
The 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)
Clay mineral: Bentonite (Hojoon Super Clay: swelling power 30ml / 2g)
Atapulgite (Atagel 50, Hayashi Kasei Co., Ltd .: Swelling power 25ml / 2g)
Powder foaming agent: trade name “Lipolane PB-800”, manufactured by Lion Corporation

(Production method)
First, as powder components, cement, clay mineral, and powder foaming agent are put in a container with a capacity of 5 L, two rubber stoppers are added, and they are mixed by shaking. 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, 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. 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 observed for visual observation, and the presence or absence of defoaming, separation, and accumulation of water at the bottom was evaluated.
These results are shown in Table 2.

(Evaluation results)
As shown in Table 2, the air milk of each Example had a compressive strength exceeding 20 kN / m ² at a material age of 1 day. Furthermore, no defoaming, separation, or accumulation of water at the bottom was found in visual property observation.
As described above, it was found that the air milk of each Example had high compressive strength at the age of 1 day, sufficiently contained air bubbles, suppressed air bubble removal, and high air bubble uniformity.

On the other hand, in Comparative Examples 1 and 3 containing no clay mineral, the foam disappeared and decreased, and there was no uniform foam. Furthermore, separation of cement milk by defoaming occurred. Furthermore, the compression strength could not be measured because the material was uncured at 1 day of age.
In Comparative Example 2 in which the amount of the clay mineral was small, the amount of air was relatively large, but in the property observation, a water pool was generated due to separation. Furthermore, the compressive strength was less than 20 kN / m ² at the age of 1 day.
Moreover, in Comparative Example 4 with a large amount of clay mineral, kneading could not be performed, and cement milk could not be obtained.

Claims (4)

It contains cement and clay mineral is a powder component, an alpha olefin sulfonate-based powder foaming agent, wherein the clay mineral is 25 wt% or less than 10% by weight relative to the total amount of the clay mineral and the cement Mixing to form a mixed powder,
And a step of adding water to the mixed powder and kneading the mixture .   The method for producing a cement composition according to claim 1, wherein the clay mineral is at least one selected from the group consisting of a layered clay mineral, a fibrous clay mineral, and a fired product thereof. The bubble according to claim 1 or 2, wherein the powder foaming agent is mixed so that the powder foaming agent is contained in an amount of 0.03% by mass or more and 1% by mass or less based on a total amount of the cement and the clay mineral. A method for producing a cement composition. Cement and clay mineral, which are powder components, and alpha olefin sulfonic acid-based powder foaming agent are contained in an amount of 10% by mass to 25% by mass with respect to the total amount of the cement and the clay mineral. The mixed powder is mixed to form a mixed powder, water is added to the mixed powder and kneaded to obtain a foam-containing cement composition, and the foam-containing cement composition is transported to a construction site for construction. A construction method using a bubble-containing cement composition.