JP5526944B2 - Construction method of concrete structure - Google Patents

Description

  The present invention relates to a construction method of a foundation concrete structure for buildings using a self-leveling hydraulic composition and a foundation concrete structure for buildings obtained by the construction method.

  The hydraulic composition used as a self-leveling material is not only high in fluidity, but also has a fluidity retention time that is long enough to secure an appropriate working time from the aspect of facilitating construction work, sufficient to enable early opening It is considered that it is necessary to have a fast curing property, dimensional stability as a structural material, high strength characteristics, and water resistance. The self-flowing hydraulic composition used as the self-leveling material is roughly classified into two types: a gypsum system and a cement system, according to the hydraulic components contained. The gypsum system has the advantage that it has good dimensional stability and hardens in a short time, but has low water resistance and has the disadvantage that rust is easily generated when reinforcing bars are used. On the other hand, the cement system has the disadvantages that the shrinkage is large and the curing speed is slow, contrary to gypsum yarn. In particular, there is a drawback that the curing rate is remarkably slow at low temperatures, and in the case of using a fast-curing cement, there is a point that although the curing rate is improved, the fluidity is low.

  Patent Document 1 discloses a low-shrinkage self-leveling material having excellent fluidity, good workability, no material separation, excellent surface hardness after curing (Shore hardness) and good surface accuracy. Disclosed is a self-leveling cement composition characterized by comprising 0.1 to 0.45% by weight of aluminum sulfate as a main component and aluminum sulfate based on the total amount of cement and aggregate. ing.

In Patent Document 2, as a high-strength self-leveling cement composition that is excellent in fluidity and self-smoothness, particularly extremely high in compressive strength after curing and adhesive strength with a base, a Blaine specific surface area is 7000 compared to Portland cement. A high-strength self-leveling cement composition comprising 5 to 30% by weight of one or more inorganic finely pulverized powders selected from the group consisting of -30000 cm ² / g limestone powder, fly ash, and granulated blast furnace slag Is disclosed.

  Patent Document 3 discloses a self-leveling hydraulic composition comprising a main component composed of Portland cement, fine aggregate, admixture and expansion material, and aluminum sulfate, shrinkage reducing agent, limestone fine powder, thickener and water retention agent. A self-leveling hydraulic composition is disclosed, wherein the thickener is a thickener of a cellulose-based water-soluble polymer, and the water-retaining agent is a water-retaining agent of a polyether-based water-soluble polymer. Yes.

  Patent Document 4 describes a construction method for a foundation concrete structure for buildings, which includes pouring and curing a hydraulic mortar prepared by kneading a self-leveling hydraulic composition and water. . Moreover, in the construction method described in Patent Document 4, the self-leveling hydraulic composition is composed of a main component composed of Portland cement, fine aggregate, admixture, and expansion material, aluminum sulfate, shrinkage reducing agent, limestone fine powder, It includes a thickener and a water retention agent, the thickener is a thickener of a cellulose water-soluble polymer, and the water retention agent is a water retention agent of a polyether water-soluble polymer.

  In addition, when constructing a concrete structure using a hydraulic composition composed of various cements, the construction temperature, which is one of the construction conditions, is mortar or slurry (hydraulic slurry) using the hydraulic composition. Therefore, various studies have been conducted to reduce the influence. The characteristics of the mortar and slurry using the hydraulic composition may be affected by the content ratio of the trace components of the constituent material and the content ratio of the constituent components.

  As a method for producing a self-fluid hydraulic composition in which the fluidity of the slurry does not vary between production lots of hydraulic components, the fluidity is stable, and the product yield at the time of production is improved, Patent Document 5 describes: Self-fluidity prepared by measuring the amount of free calcium oxide contained in Portland cement and mixing a hydraulic component containing Portland cement with a free calcium oxide amount of 1% by mass or less and a water reducing agent and / or thickener. A method for producing a hydraulic composition is disclosed.

  Patent Document 6 discloses a self-flowing hydraulic composition comprising a hydraulic component containing alumina cement and Portland cement, and a water reducing agent and / or a thickening agent. A self-flowing hydraulic composition using alumina cement in which the amount of aluminum oxide (X) and the amount of calcium oxide (Y) satisfy (X / Y) ≧ 1.05 is disclosed.

JP-A-8-333150 JP-A-8-208285 JP 2008-247666 A JP 2008-248554 A JP 2006-168999 A JP 2006-240899 A

  However, these self-leveling materials cannot fully exhibit their intended quick-hardness and workability depending on the use temperature, and do not cover use in a wide range of temperature conditions from low temperature to high temperature. That is, the fast curability is greatly reduced at low temperatures due to the delay in curing, and good handling properties may not be obtained at high temperatures due to the decrease in fluidity retention. Therefore, in a wide range of temperature conditions from low temperature to high temperature, it has both super-hardness that enables opening on the day of construction and fluidity retention, and temperature dependence that can cope with temperature differences due to seasonal, time differences, regional differences, etc. A material with a small amount was desired.

  Therefore, an object of the present invention is to provide a self-leveling hydraulic composition that combines good construction workability and excellent hardened body characteristics in obtaining a foundation concrete structure for buildings. In addition, the present invention aims to provide a hydraulic composition for obtaining a hydraulic slurry that can stably maintain high fluidity for a long time even when the temperature conditions during construction change, and is excellent in handling properties. To do.

  In order to solve the above problems, the present inventors have conducted intensive research and completed the present invention.

  That is, the present invention includes a step of providing a formwork for forming a foundation concrete structure for a building, a step of arranging reinforcing bars in the formwork, and placing concrete in the formwork. A step of forming a base concrete part, and a process of pouring and curing a hydraulic mortar prepared by kneading a self-leveling hydraulic composition and water on the upper surface of the base concrete part. It is the construction method of the foundation concrete structure for buildings, Comprising: It is a construction method of the foundation concrete structure for buildings in which the self-leveling hydraulic composition contains a predetermined component. The self-leveling hydraulic composition containing a predetermined component is a self-leveling water containing a main component comprising Portland cement, fine aggregate, an admixture and an expansion material, and aluminum sulfate, a shrinkage reducing agent and a thickening agent. It is a self-leveling hydraulic composition which is a hard composition and is a thickener containing a cellulose-based water-soluble polymer using ethyl cellulose as a thickener. According to the construction method of the present invention, even when the temperature condition during construction changes, it is possible to stably maintain a high fluidity for a long time and obtain a hydraulic slurry excellent in handling properties. The construction method of the foundation concrete structure for buildings and the foundation concrete structure for buildings can be obtained.

The preferable aspect of the construction method of the foundation concrete structure for buildings of this invention is shown below. In the present invention, these embodiments can be appropriately combined.
(1) The main component of the self-leveling hydraulic composition is composed of 100 parts by weight of Portland cement, 100 to 400 parts by weight of fine aggregate, 5 to 150 parts by weight of admixture, and 3 to 30 parts by weight of intumescent material, and thickened. The agent is composed of a cellulose-based water-soluble polymer containing a high-viscosity type ethyl cellulose having a viscosity of 20,000 to 50,000 mPa · s at 20 ° C. in a 2% aqueous solution. In the self-leveling hydraulic composition, Portland cement The content of aluminum sulfate is 0.1 to 0.7 parts by mass, and the content of cellulose-based water-soluble polymer containing high-viscosity type ethyl cellulose is 0.005 to 100 parts by mass in total with fine aggregates. 0.2 parts by mass. The water content of the high-viscosity cellulose-based water-soluble polymer is in the above range, so that even when the temperature conditions during construction change, water that can stably maintain high fluidity for a long time and has excellent handling properties. A hard slurry can be provided.
(2) The content of the shrinkage reducing agent in the self-leveling hydraulic composition is 0.1 to 3 parts by mass with respect to 100 parts by mass of the total of the main components. By mix | blending a shrinkage reducing agent, generation | occurrence | production of the crack at the time of hardening can be suppressed and durability can be improved.
(3) The self-leveling hydraulic composition further contains fibers, and the fiber content is 0.01 to 5 parts by mass with respect to 100 parts by mass as the total of the main components. By containing the fiber, a cured product having excellent bending strength and hardly or hardly causing cracks can be stably obtained.
(4) The self-leveling hydraulic composition further includes a fluidizing agent and an antifoaming agent, and the content of the fluidizing agent is 0.01 to 3 parts by mass with respect to a total of 100 parts by mass of the main component, Content of an antifoamer is 0.01-3 mass parts with respect to a total of 100 mass parts of a main component. When the fluidizing agent and the antifoaming agent are in the above ranges, an effect that is economically commensurate with the content can be achieved.
(5) The self-leveling hydraulic composition further contains another setting modifier other than aluminum sulfate. By including a setting regulator, the pot life of the self-leveling hydraulic composition can be adjusted.
(6) The process of pouring and hardening hydraulic mortar places the concrete for forming the base concrete part, and after pouring the concrete's breathing water (floating water), pours and builds the hydraulic mortar. Including that. Since the hydraulic mortar is poured before the concrete is hardened, the base concrete portion and the hardened mortar body are integrated to prevent peeling.
(7) The step of forming the base concrete part is to form a base concrete part having a primer hardened body layer by applying a primer to the upper surface of the hardened concrete and drying it to form a primer hardened body layer. Including. By disposing the cured primer layer between the portion where the foundation concrete is placed and the hydraulic mortar layer of the self-leveling hydraulic composition, peeling at the interface between the two layers can be prevented.
(8) The foundation concrete structure for buildings is for a one-story to three-story house. By the construction method of the present invention, it is possible to obtain a foundation concrete structure for a building having a one-story to three-story house.

  Moreover, this invention is the foundation concrete structure for buildings obtained by the construction method of the foundation concrete structure for buildings mentioned above. The basic concrete structure for buildings of the present invention combines good workability and excellent hardened body characteristics, and can maintain stable and high fluidity for a long time even when the temperature conditions during construction change, It is a foundation concrete structure for buildings from which a hydraulic slurry having excellent handling properties can be obtained.

  In the construction method of the foundation concrete structure for building of the present invention, by using a predetermined self-leveling hydraulic composition, it has both good workability and excellent hardened body characteristics, and the temperature condition during construction changes. In this case, it is possible to obtain a foundation concrete structure for building construction and a foundation concrete structure for building, which can maintain a stable and high fluidity for a long time and obtain a hydraulic slurry with excellent handling properties. it can.

  Furthermore, in the construction method of the foundation concrete structure for building of the present invention, even if the temperature condition during construction changes, it is possible to maintain a stable and high fluidity for a long time. Thus, the homogeneity of the joining portion of the hydraulic mortar applied from the above can be remarkably improved, and a cured mortar body of hydraulic mortar having stable and excellent characteristics can be obtained.

  Furthermore, even when the temperature conditions during construction, which are the characteristics described above, change, high construction efficiency and good construction workability are achieved through stable and long mortar flow rate and rapid strength development. It is possible to obtain a foundation concrete structure for buildings that has a horizontal level on the surface of the cured mortar body, has a good surface finish, and has a hardened mortar body with high compressive strength on the surface. Can be formed.

It is a schematic diagram which shows the outline | summary of a construction procedure about the construction method of the foundation concrete structure for buildings of this invention. It is a perspective view which shows typically the confluence | merging location of the hydraulic mortar at the time of pouring construction of hydraulic mortar. It is a plane schematic diagram of an example of the mortar hardening body which has a corner | angular part obtained by pouring and constructing hydraulic mortar. It is a figure which shows the outline of self-leveling property evaluation using SL measuring device. It is a plane schematic diagram which shows the construction method of the top end of the foundation concrete structure for buildings, and shows the state before pouring hydraulic mortar. It is a plane schematic diagram which shows the construction method of the top edge of the foundation concrete structure for buildings, and shows a state where hydraulic mortar was poured into the ceiling edge construction part A. It is a plane schematic diagram which shows the construction method of the top edge of the foundation concrete structure for buildings, and shows a state where the casting of hydraulic mortar into the ceiling edge construction part B is started.

  The present invention is a construction method of a foundation concrete structure for buildings using a predetermined self-leveling hydraulic composition containing a cellulose-based water-soluble polymer thickener containing ethyl cellulose. An example of an embodiment will be described with reference to the drawings shown in FIGS. 1a to 1e for a foundation concrete structure for buildings obtained by the construction method of the present invention.

  FIG. 1 a schematically shows a partial cross section of the ground 11 on which a foundation concrete structure for a building is constructed. The ground 11 where the building foundation concrete structure is formed excavates the earth and sand using a backhoe and then lays a crushed stone (consolidated layer) 12 and rolls it using a plate compactor or the like.

  FIG. 1 b shows a state in which a formwork 13 of a foundation concrete structure for a building is provided on the upper surface of the ground 11 and a reinforcing bar 14 is arranged (reinforced) in the formwork. Anchor bolts 15 are firmly fixed to the reinforcing bars 14 in the mold 13 after confirming the installation location.

  FIG. 1c shows that the concrete 16 for foundation is poured into the formwork 13 in which the reinforcing bars 14 and the anchor bolts 15 are installed, and is compacted by using a vibrator. The state which formed the concrete part 21 is shown. The concrete 16 for foundation used is not particularly limited, and the concrete 16 for foundation having a general architectural composition can be appropriately selected and used.

  FIG. 1d shows a state in which the hydraulic mortar 24 of the self-leveling hydraulic composition is poured so as to adjust the height of the top to a predetermined height. The timing for constructing the hydraulic mortar 24 of the self-leveling hydraulic composition is preferably after several hours after placing the concrete in the mold 13 and after the breathing water (floating water) on the concrete surface is drawn, When the breathing water (floating water) on the concrete surface is drawn, the hydraulic mortar 24 can be poured. When the hydraulic mortar 24 is poured before the concrete is hardened after the breathing water is drawn, the base concrete portion and the mortar hardened body are integrated without applying a primer and forming a primer hardened body layer. Peeling can be prevented.

  In addition, when concrete 16 is placed in the mold 13 due to circumstances such as a construction schedule and the hydraulic mortar 24 cannot be poured on that day, the concrete 16 in the mold 13 is cured after the concrete 16 is cured. After removing the latency on the top surface (white paste), oil, dust, etc., applying and drying the primer, the hydraulic mortar 24 can be poured.

  FIG. 1e shows a hydraulic mortar 24 of a self-leveling hydraulic composition that can be applied to the surface of the base concrete portion 22 and maintain stable and good fluidity for a long time even when the temperature conditions during the application change. A state in which the mold 13 is removed after curing is shown. A mortar hardened body 17 adjusted to a predetermined height using a self-leveling hydraulic composition is formed on the base concrete part surface 22.

  In the construction method of the foundation concrete structure for building according to the present invention, a stable and large mortar flow rate can be obtained for a long time even when the temperature condition during construction is changed while having excellent material separation resistance. It is preferable to select and use a self-leveling hydraulic composition. When the mortar flow rate is stable for a long time even if the temperature condition changes, not only the work efficiency during construction is improved, but also the hydraulic mortar 24 constructed from a plurality of locations as shown in FIGS. This has a significant effect on the homogenization of the hydraulic mortar 24 at the junction 25 and not only improves the finish of the surface of the mortar cured body 17 but also significantly improves the variation of the construction thickness and the strength of the cured body. .

  Next, an example of a procedure for pouring hydraulic mortar into the ground concrete surface 22 will be described.

  In FIG. 5, the plane schematic diagram before pouring hydraulic mortar into the surface concrete part surface 22 is shown. The planar shape of the foundation concrete structure for buildings can take various shapes depending on the shape of the building. Therefore, in the foundation concrete structure for buildings, a plurality of top end construction portions (in the case of FIGS. 5 to 7, the top end construction portion A32 and the top end construction portion B34) may include many parts to be connected. is there. A weir 40 is provided in a portion to which the top end construction portion is connected, and hydraulic mortar can be poured into different top end construction portions sequentially. In the schematic plan view shown in FIG. 6, the hydraulic mortar 24 is poured into the top end construction portion A <b> 32 using a bucket 50 or the like.

  Next, as shown in FIG. 7, the weir 40 is removed, and the hydraulic mortar 24 is poured into the top end construction part B34 using a bucket 50 or the like. The hydraulic mortar 62 of the top end construction portion A32 and the hydraulic mortar 64 of the top end construction portion B34 merge at the place where the weir 40 is present. At this time, it is necessary for the hydraulic mortars 62 and 64 to be familiar. By using the hydraulic mortars 62 and 64 of a predetermined self-leveling hydraulic composition containing a cellulose-based water-soluble polymer thickener containing ethyl cellulose, it is stable even when the temperature conditions during construction change. Since the high fluidity can be maintained for a long time, the familiarity when the hydraulic mortars 62 and 64 merge at the place where the weir 40 is present can be improved. By moving the bucket 50 containing the hydraulic mortar 24 and moving the pouring position of the hydraulic mortar 24 in the direction away from the place where the weir 40 was, as shown by the arrows in FIG. The hydraulic mortar 64 can be poured into the whole end construction part B34.

  In addition, as shown in FIG. 6, when the concrete cast for the formation of the ground concrete part 21 is hardened, before pouring the hydraulic mortar 24, it is applied to the upper surface of the hardened concrete (the ground concrete part surface 22). A primer cured body layer can also be formed by applying and drying a primer. By disposing the cured primer layer between the base concrete portion 21 and the hydraulic mortar 24 layer of the self-leveling hydraulic composition, peeling at the interface between the two layers can be prevented. Therefore, it is effective to form a hardened primer layer when concrete 16 is placed in the mold 23 due to circumstances such as a construction schedule and hydraulic mortar cannot be poured on that day.

  The construction method as described above can maintain a stable and high fluidity for a long time even when the temperature condition during construction changes, so it has a horizontal level on the surface of the cured mortar and has a good surface finish. It is possible to obtain a foundation concrete structure for buildings having a mortar cured body with high compressive strength on the surface layer.

  Next, the self-leveling hydraulic composition used for the construction method of the foundation concrete structure for buildings of the present invention will be described. In the construction method of the present invention, since the predetermined self-leveling hydraulic composition described below is used, even when the temperature condition during construction changes, it is possible to stably maintain high fluidity for a long time and to improve the handling property. An excellent hydraulic slurry can be obtained.

  The self-leveling hydraulic composition used in the construction method of the present invention contains main components composed of Portland cement, fine aggregate, admixture and expansion material, and further contains aluminum sulfate, shrinkage reducing agent and thickener. The self-leveling hydraulic composition that can maintain a stable and high fluidity for a long time even when the temperature conditions during construction used in the construction method of the present invention are changed is a cellulose-based thickener containing ethyl cellulose. It is characterized by being a thickener containing a water-soluble polymer. If hydraulic mortar of the self-leveling hydraulic composition used in the construction method of the present invention is used, even if the temperature conditions during construction change, stable and high fluidity can be maintained for a long time, and handling properties An excellent hydraulic slurry can be obtained. Hereinafter, the self-leveling hydraulic composition used in the construction method of the present invention will be described.

  The self-leveling hydraulic composition used in the construction method of the present invention is a cellulose-based water-soluble composition containing aluminum sulfate, a shrinkage reducing agent, and ethyl cellulose together with main components composed of Portland cement, fine aggregate, admixture and expansion material. Contains polymer thickener.

  Portland cement, which is one of the main components and is a hydraulic component, includes ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, medium-heated Portland cement, sulfate-resistant Portland cement, low-heat Portland cement that conforms to JIS. And white Portland cement and combinations thereof. Further, instead of Portland cement, mixed cement such as blast furnace cement, fly ash cement and silica cement can be used.

  The self-leveling hydraulic composition used in the construction method of the present invention contains fine aggregate as one of the main components. Fine aggregates include silica sand, river sand, sea sand, mountain sand and crushed sand, alumina clinker, silica powder, clay mineral, waste FCC catalyst and inorganic materials such as limestone, urethane crushed, EVA foam and foaming resin It can select suitably from resin pulverized materials etc., such as. In particular, as the fine aggregate, one or a mixture of two or more selected from sands such as quartz sand, river sand, sea sand, mountain sand, crushed sand, waste FCC catalyst, quartz powder and alumina clinker is preferably used. it can.

  The particle size of the fine aggregate is preferably 2 mm or less, more preferably 1 mm or less, more preferably 0.7 mm or less, particularly preferably 0.6 mm or less. Those having a particle size of can be suitably used. The particle size of the fine aggregate is measured using several sieves having different nominal dimensions defined in JIS / Z-8801.

  The content of fine aggregate in the self-leveling hydraulic composition used in the construction method of the present invention is preferably 100 to 400 parts by weight, more preferably 120 to 350 parts by weight, with respect to 100 parts by weight of Portland cement. More preferably, it is 140-320 mass parts, Most preferably, it is the range of 150-300 mass parts. When the content of the fine aggregate in the self-leveling hydraulic composition used in the construction method of the present invention is within the above range, a mortar slurry excellent in fluidity and material separation resistance can be obtained, It is preferable because a cured product having an excellent surface state and high strength can be obtained.

  Examples of the admixture that is one of the main components include slag powder such as fly ash and blast furnace slag fine powder, and these can be used alone or in combination of two or more. In particular, bending and compressive strength can be increased by including blast furnace slag fine powder. Therefore, the admixture preferably contains blast furnace slag fine powder.

An admixture having a fineness (Brain specific surface area) of 3,000 to 5,000 cm ² / g can be preferably used. If the Blaine specific surface area of the admixture is less than 3,000 cm ² / g, the effect of increasing the material separation resistance of the mortar slurry will be poor, and the hydration reactivity of the admixture will be poor. On the other hand, when the Blaine specific surface area of the admixture exceeds 5,000 cm ² / g, the tendency of the viscosity of the mortar slurry to increase becomes remarkable, and the fluidity may be inhibited.

  The content of the admixture in the self-leveling hydraulic composition used in the construction method of the present invention is preferably 5 to 150 parts by mass, more preferably 10 to 120 parts by mass with respect to 100 parts by mass of Portland cement. The range is preferably 15 to 90 parts by mass, particularly preferably 20 to 80 parts by mass. When the admixture has a content in the above range, a mortar cured product having excellent surface properties and compressive strength can be obtained.

  Examples of the expansion material that is one of the main components include expansion materials mainly composed of ettringite-based calcium sulfoaluminate, expansion materials mainly composed of calcium oxide, aluminum oxide and sulfur trioxide, and lime-based materials such as quick lime. Examples of the expansion material and gypsum-based expansion material such as gypsum, and the like can be used as one or a mixture of two or more of these expansion materials. As the expansion material, it is preferable to use a gypsum-based expansion material, particularly an expansion material containing gypsum or gypsum.

  The content of the expansion material in the self-leveling hydraulic composition used in the construction method of the present invention is preferably 3 to 30 parts by mass, more preferably 5 to 25 parts by mass, with respect to 100 parts by mass of Portland cement. Preferably it is 8-20 mass parts, Most preferably, it can be the range of 10-18 mass parts. It is preferable for the inflatable material to be in the above-mentioned content range because appropriate expansibility can be expressed and the change in the length of the mortar cured body can be suppressed, and at the same time, generation of cracks due to excessive expansion action can be prevented.

  Gypsum that is particularly preferably used as the expansion material is gypsum such as anhydrous and semi-water. Regardless of the type of gypsum such as anhydrous and semi-water, the expansion material can be used as one kind or a mixture of two or more kinds thereof.

  Examples of limes preferably used as the expansion material include quick lime, slaked lime, calcined dolomite, and the like, and can be used as one kind or a mixture of two or more kinds thereof.

  The self-leveling hydraulic composition used in the construction method of the present invention is a cellulosic water-soluble polymer containing aluminum sulfate, a shrinkage reducing agent, and ethyl cellulose together with main components composed of Portland cement, fine aggregate, admixture and expansion material. Contains a thickener.

  Aluminum sulfate contained in the self-leveling hydraulic composition used in the construction method of the present invention has a function as a setting accelerator. The content of aluminum sulfate is preferably 0.1 to 0.7 parts by mass, more preferably 0.15 to 0.6 parts by mass with respect to the total amount (100 parts by mass) of Portland cement and fine aggregate. More preferably, the range is 0.2 to 0.5 parts by mass, and particularly preferably 0.25 to 0.45 parts by mass. By making the content of aluminum sulfate in the above range, it is possible to obtain a good strength enhancement effect, and it is possible to obtain a good effect of reducing shrinkage of the cured product due to this early strength development. When there is too little content of aluminum sulfate, the expression of the shrinkage reduction effect will be insufficient. In addition, the shrinkage reduction effect increases as the content of aluminum sulfate increases, but if added excessively, the setting effect of cement becomes prominent and fluidity of the mortar slurry decreases, and fine cracks appear in the hardened body. May occur. Therefore, the content of aluminum sulfate is preferably in the above range.

  The self-leveling hydraulic composition used in the construction method of the present invention contains a shrinkage reducing agent. For the self-leveling hydraulic composition used in the construction method of the present invention, by adding a shrinkage reducing agent within a range that does not impair its characteristics, the occurrence of cracks during curing is suppressed and durability is improved. Can do.

  A known shrinkage reducing agent can be used as the shrinkage reducing agent. As the shrinkage reducing agent, in particular, those having an alkylene oxide polymer represented by the following chemical formula (1) in the skeleton of the chemical structure can be suitably used.

（但し式（１）中、Ｒ^１及びＲ^２は、互いに独立してアルキル基、フェニル基、シクロアルキル基、水素基などであり、Ａは炭素数２〜３の１種のアルキレン基（エチレン基、プロピレン基）又はランダム若しくはブロック重合させた２種のアルキレン基であり、ｎは２〜２０の整数である。）

(In the formula (1), R ¹ and R ² are each independently an alkyl group, a phenyl group, a cycloalkyl group, a hydrogen group, etc., and A is an alkylene group having 2 to 3 carbon atoms (ethylene Group, propylene group) or two kinds of random or block polymerized alkylene groups, and n is an integer of 2 to 20.)

  As the shrinkage reducing agent, for example, polyalkylene glycols such as polypropylene glycol and poly (propylene / ethylene) glycol and generally known ones such as alkoxy poly (propylene / ethylene) glycol having 1 to 6 carbon atoms are appropriately selected and used. be able to.

  The content of the shrinkage reducing agent relative to the self-leveling hydraulic composition can be appropriately selected according to the content of the main component and subcomponent used. For example, the content of the shrinkage reducing agent is preferably 0.1 to 3 parts by mass, more preferably 0.13 to 2 parts by mass, and more preferably 0.15 to 1 part by mass with respect to 100 parts by mass of the main component. More preferably, the amount is 0.18 to 0.8 parts by mass.

  In the self-leveling hydraulic composition used in the construction method of the present invention, the self-leveling property of the hydraulic mortar and the material separation resistance are balanced at a high level, and further, the hydraulic property in the initial stage in which the hydraulic mortar is cured. In order to suppress the drying of the mortar surface and avoid the occurrence of cracks, a thickener containing a cellulose-based water-soluble polymer containing ethyl cellulose is used.

  The thickener contained in the self-leveling hydraulic composition used in the construction method of the present invention has a 2% aqueous solution viscosity at 20 ° C. of 20,000 to 50,000 mPa · s, preferably 20,000 to 40,000 mPa -It consists of a high viscosity type cellulosic water-soluble polymer which is s. In the present specification, the viscosity refers to a 2% aqueous solution of a cellulose-based water-soluble polymer for thickeners A and B, using a B-type viscometer (Toki Sangyo Digital Viscometer DVL-B type). The value measured at a rotational speed of 12 rpm and 20 ° C., and the thickener E, a 1% aqueous solution of a cellulose-based water-soluble polymer measured using a LV Brookfield viscometer at a rotational speed of 12 rpm and 20 ° C. Viscosity C is a value measured by HEAD, and thickener D is a value measured by Samsung.

  As a specific example of the thickener, conventionally, a cellulose-based thickener containing methylcellulose (for example, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, etc.) has often been used. Then, a cellulose thickener containing ethyl cellulose is used. Particularly preferably, a cellulose thickener containing ethyl hydroxyethyl cellulose is used.

  The viscosity of the cellulosic water-soluble polymer contained in the thickener can be adjusted by selecting a cellulose-based water-soluble polymer thickener containing commercially available ethyl cellulose having a predetermined viscosity. As a thickener containing a cellulose-based water-soluble polymer containing ethyl cellulose, various types having different viscosities are commercially available.

  The content of the water-soluble water-soluble polymer containing high-viscosity type ethyl cellulose contained in the thickener is 0.005 to 0.2 mass relative to the total amount (100 parts by mass) of Portland cement and fine aggregate. Parts, preferably 0.008 to 0.18 parts by mass, more preferably 0.01 to 0.15 parts by mass. When the content of the high-viscosity cellulose-based water-soluble polymer is within the above range, the effect of the present invention can be ensured. In addition, when the content of the thickener is reduced, the effect of the thickener is reduced, and when the content of the thickener is increased, the fluidity may be lowered.

  By adding a predetermined thickener containing ethyl cellulose to the self-leveling hydraulic composition used in the construction method of the present invention, there is an effect of increasing the material separation resistance of hydraulic mortar having particularly excellent fluidity. Significantly, material separation can be avoided / suppressed with almost no loss of mortar fluidity. Moreover, even when the temperature conditions during construction change, high fluidity can be maintained stably for a long time.

  The self-leveling hydraulic composition contains one or more of a setting adjuster (setting retarder and setting accelerator), a fluidizing agent (water reducing agent), an antifoaming agent, a resin powder, and a fiber as necessary. be able to.

  The self-leveling hydraulic composition used in the construction method of the present invention can contain a setting modifier other than aluminum sulfate, if necessary. As the setting regulator, a setting retarding agent that is a component that delays the setting and a setting accelerator that is a component that accelerates the setting can be used alone or in combination.

  In the self-leveling hydraulic composition used in the construction method of the present invention, the fluidity, pot life, curing properties, etc. are selected by appropriately selecting the components, content and mixing ratio of the setting retarder and / or setting accelerator. Can be adjusted. Specifically, by appropriately performing the above selection, at 20 ° C., the pot life of the self-leveling hydraulic composition can be adjusted to an arbitrary time from about several minutes to about 1 hour.

  As the setting accelerator, a known setting accelerator can be used. Examples of setting accelerators include lithium salts, specifically, lithium carbonate, lithium chloride, lithium sulfate, lithium nitrate, lithium hydroxide and other inorganic lithium salts, lithium acetate, lithium tartrate, lithium malate, lithium citrate, etc. One or more selected from organic lithium salts and metal sulfates other than aluminum sulfate can be preferably used. In particular, by using aluminum sulfate and potassium sulfate in combination, a stable setting promoting effect can be obtained. Moreover, it is preferable to use aluminum sulfate and potassium sulfate as a setting accelerator from the point of availability and low cost.

  When using potassium sulfate as a setting accelerator, the amount used (content) is preferably 0.1 to 0.9 parts by mass with respect to the total amount (100 parts by mass) of Portland cement and fine aggregate. More preferably, it is 0.15-0.8 mass part, More preferably, it is 0.2-0.75 mass part, Especially preferably, it is preferable that it is the range of 0.25-0.7 mass part. When the content of potassium sulfate is in the above range, it is possible to obtain a good strength enhancement effect for hydraulic mortar.

  As the particle size of the setting accelerator, it is preferable to use a particle which does not interfere with the characteristics of the self-leveling hydraulic composition used in the construction method of the present invention. Specifically, the particle size of the setting accelerator is preferably 50 μm or less.

  As the setting retarder, a known setting retarder can be used. Examples of setting retarders include sodium salts, specifically selected from inorganic sodium salts such as sodium sulfate and sodium bicarbonate, and organic sodium salts such as sodium tartrate, sodium malate, sodium citrate and sodium gluconate. The above can be used.

  The content of the setting retarder in the self-leveling hydraulic composition used in the construction method of the present invention is preferably 0.01 to 1 with respect to the total amount (100 parts by mass) of Portland cement and fine aggregate. It is 0.0 mass part, More preferably, it is 0.015-0.85 mass part, More preferably, it is 0.020-0.8 mass part, Most preferably, it is the range of 0.025-0.75 mass part. When the content of the setting retarder is in the above range, preferable workability can be obtained.

  As a fluidizing agent, naphthalene sulfonate formalin condensate, olefin unsaturated carboxylic acid copolymer salt, lignin sulfonate, casein, casein calcium, polyether-based and polycarboxylic acid-based fluidizing agents are commercially available. A thing can be used as those 1 type, or 2 or more types of mixtures irrespective of the kind. The fluidizing agent can also have a water reducing effect.

  A fluidizing agent (water reducing agent) can be added as long as the characteristics of the present invention are not impaired. The content of the fluidizing agent (water reducing agent) in the self-leveling hydraulic composition used in the construction method of the present invention is preferably 0.01 to 3 parts by mass, more preferably 0 to 100 parts by mass of the main component. 0.02 to 2 parts by mass, more preferably 0.04 to 1 part by mass, and particularly preferably 0.06 to 0.5 part by mass. If the content of the fluidizing agent (water reducing agent) is too small, sufficient effects are not exhibited. Moreover, even if the content of the fluidizing agent (water reducing agent) is too much, an effect commensurate with the content cannot be expected and not only is uneconomical, but the amount of kneading water to obtain the required fluidity increases, At the same time, the viscosity increases and the filling property may deteriorate.

  In the self-leveling hydraulic composition used in the construction method of the present invention, it is preferable to use an antifoaming agent in combination with the above thickener. When the self-leveling hydraulic composition used in the construction method of the present invention contains an antifoaming agent, it is preferable for suppressing the separation of fine aggregates contained in the main component, suppressing the generation of bubbles and improving the surface of the mortar hardened body. And the properties as a self-leveling material can be improved.

  Anti-foaming agents contained in the self-leveling hydraulic composition used in the construction method of the present invention include synthetic materials such as silicon-based, alcohol-based and polyether-based materials, mineral oils derived from petroleum refining, and natural materials derived from plants For example, one or more known ones can be selected and used.

  An antifoamer can be added in the range which does not impair the characteristic of the self-leveling hydraulic composition used for the construction method of this invention. The content of the antifoaming agent in the self-leveling hydraulic composition used in the construction method of the present invention is preferably 0.01 to 3 parts by mass, more preferably 0.02 to 100 parts by mass of the main component. It is 1.5 mass parts, More preferably, it is 0.03-1 mass part, Most preferably, it is 0.04-0.5 mass part. When the content of the antifoaming agent is within the above range, a good antifoaming effect is recognized, and the fluidity of the hydraulic mortar slurry and the finish of the surface of the mortar cured body can be preferably adjusted.

  The self-leveling hydraulic composition used in the construction method of the present invention can contain fibers. Fibers include polyethylene, ethylene / vinyl acetate copolymer (EVA), polyolefins such as polypropylene, organic fibers composed of resin components such as polyester, polyamide, polyvinyl alcohol, and polyvinyl chloride, and metal systems such as stainless steel fibers and aluminum fibers. A fiber etc. can be used and it can use as a 1 type, or 2 or more types of mixture of these.

  The fiber contained in the self-leveling hydraulic composition used in the construction method of the present invention is preferably an organic fiber because of its low cost and easy handling. The fiber length of the organic fiber is preferably about 0.5 to 15 mm.

  The fiber content of the self-leveling hydraulic composition used in the construction method of the present invention is preferably 0.01 to 5 parts by mass, more preferably 0.01 to 2 parts by mass, with respect to 100 parts by mass of the main component. More preferably, it is 0.02-1 mass part, Most preferably, it is 0.03-0.2 mass part. By containing the fiber of the above-mentioned content with respect to the self-leveling hydraulic composition of the present invention, it is possible to stably obtain a cured product that is excellent in bending strength and hardly or does not generate cracks.

  The self-leveling hydraulic composition used in the construction method of the present invention can contain a resin powder. As the resin powder, polymer particles (such as re-emulsified resin particles) obtained by removing a liquid component from a known polymer emulsion for construction or building materials can be used. For example, polymer resin particles obtained by removing a liquid component of a polymer emulsion obtained by emulsion polymerization of an α, β-ethylenically unsaturated monomer can be used as the resin powder.

  The content of the resin powder with respect to the self-leveling hydraulic composition used for the construction method of the present invention is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 8 parts by mass with respect to 100 parts by mass of the main component. More preferably, the content can be 0.01 to 5 parts by mass, and particularly preferably 0.05 to 2 parts by mass.

Examples of the α, β-ethylenically unsaturated monomer that can be used as the resin powder include known α, β-ethylenically unsaturated monomers. Examples of the α, β-ethylenically unsaturated monomer include acrylic acid and derivatives thereof such as esters, methacrylic acid and derivatives such as esters, α-olefins such as ethylene and propylene, aromatics such as vinyl acetate and styrene. Tertiary fatty acid vinyl esters having 9 to 11 carbon atoms (R—COO—CH═CH ₂ , R is a tertiary carbon having 9 to 11 carbon atoms, such as vinyls, vinyl chloride, and versatic acid vinyl esters. ) And the like.

  A hydraulic mortar can be produced by blending and kneading the self-leveling hydraulic composition used in the construction method of the present invention and water. Moreover, since the mortar flow (flow value) of hydraulic mortar can be adjusted by selecting the compounding quantity of water suitably, the hydraulic mortar suitable for a use can be manufactured.

  In the self-leveling hydraulic composition used in the construction method of the present invention, the amount of water is preferably 10 to 70 parts by mass, more preferably 20 to 50 parts by mass, and still more preferably 100 parts by mass of the main component. It is preferable to set it as 23-40 mass parts.

  The self-leveling hydraulic composition used in the construction method of the present invention has a flow value of a hydraulic mortar prepared by mixing with water (measured according to the test method described in JASS 15M-103), preferably 180. It is preferable to be adjusted to ˜270 mm, more preferably 200 to 260 mm, and even more preferably 210 to 250 mm. Due to the flow value being in the above range, hydraulic mortar has ease of construction and excellent fluidity, in particular, stably exhibits excellent mortar flow rate, has high horizontal level accuracy, The conformability of the confluence of the slurry is excellent.

The self-leveling hydraulic composition used in the construction method of the present invention is a cured product of hydraulic mortar prepared by mixing with water, and the compressive strength at 28 days of age can obtain a value of 27 N / mm ² or more. As a result, it has sufficient strength as a foundation concrete structure for buildings.

  The self-leveling hydraulic composition used in the construction method of the present invention has an SL flow rate (L0) (second / 200 mm) using a hydraulic mortar SL meter (FIG. 4) prepared by mixing with water. It is preferably adjusted in the range of 2 to 9 seconds, more preferably in the range of 2.5 to 8 seconds. Due to the SL flow rate (L0) being in the above range, the hydraulic mortar stably demonstrates the ease of construction and the excellent mortar flow rate, and the horizontal level accuracy is high. Excellent adaptability.

  Moreover, the hydraulic mortar of the self-leveling hydraulic composition used in the construction method of the present invention does not need to be shielded from sunlight and wind using a curing sheet after construction, and the construction is easy. .

  The self-leveling hydraulic composition used in the construction method of the present invention can be used as a mortar for pouring, troweling and spraying in applications such as plastering materials, roofing materials, flooring materials and waterproofing materials. . Furthermore, the self-leveling hydraulic composition used in the construction method of the present invention can be used in the civil engineering, construction, and construction fields as a cross-sectional restoration material, a grout material, etc. used for repairing and reinforcing civil engineering structures.

  In particular, the self-leveling hydraulic composition used in the construction method of the present invention is a surface finish of concrete and a top finish (level adjustment) of the top end of a foundation concrete structure for buildings (foundation concrete structure for buildings), etc. Excellent performance. The example of the construction method in the case of using the hydraulic mortar using the self-leveling hydraulic composition used for the construction method of this invention for FIG. 2 and FIGS. If the self-leveling hydraulic composition used in the construction method of the present invention is used, it is possible to improve the construction efficiency and the horizontal level accuracy, and by forming a high strength mortar hardened body, a highly reliable building foundation. A concrete structure can be provided.

  Hereinafter, the present invention will be described in more detail based on examples. However, the present invention is not limited by the following examples.

(Flow evaluation of hydraulic mortar)
The flow value is measured according to the test method described in JASS 15M-103. A pipe made of vinyl chloride (internal volume: 100 ml) having an inner diameter of 50 mm and a height of 51 mm is placed on a glass sheet having a thickness of 5 mm, filled with kneaded hydraulic mortar, and then the pipe is pulled up. After the spread has stopped, the diameters in two perpendicular directions are measured, and the average value is taken as the flow value.

(SL evaluation of hydraulic mortar)
Using a SL (self-leveling) measuring instrument shown in FIG. 4, a weir plate is provided on a rail 30 mm wide × 30 mm high × 750 mm long, 150 mm long from the tip, and hydraulic mortar immediately after kneading is used. A predetermined amount is filled and molded. Immediately after molding, the weir plate is pulled up, and after stopping the flow of hydraulic mortar, measure the distance from the gage (installed portion of the weir plate) to the shortest portion of the flow of hydraulic mortar, and the value (SL value) Let L0. Further, the time required for hydraulic mortar to flow 200 mm from the weir plate is measured, and the measurement time is defined as SL flow rate (L0) (second / 200 mm).

  Similarly, after 30 minutes after molding, the weir plate is pulled up, and after stopping the flow of hydraulic mortar, the distance from the gauge point (the installation portion of the weir plate) to the shortest portion of the flow of hydraulic mortar is measured, and the value ( SL value) is set to L30. Moreover, the time required for hydraulic mortar to flow 200 mm from the weir plate is measured, and the measurement time is defined as SL flow rate (L30) (second / 200 mm).

(Evaluation of material separation resistance of hydraulic mortar)
Using a SL measuring device shown in FIG. 4, a rail is provided on a rail having a width of 30 mm × a height of 30 mm × a length of 750 mm, and a length of 150 mm from the tip, and a predetermined amount of slurry immediately after kneading is filled and molded. Immediately after molding, the weir plate is pulled up, and after the flow of the hydraulic mortar is stopped, the material separation state of the fine aggregate and the paste is evaluated by palpation at the head of the flow of the hydraulic mortar.

(1) Materials used: The following materials were used. The viscosity of thickeners A and B was determined by using a B-type viscometer (digital viscometer DVL-B type manufactured by Toki Sangyo Co., Ltd.) with a 2% aqueous solution of a cellulose-based water-soluble polymer. Measured at ° C. The B-type viscometer is a viscometer that measures the viscous resistance torque of the liquid acting on the rotor when the cylindrical rotor is rotated in the liquid. In the B type viscometer, it is necessary to select the type of rotor according to the viscosity to be measured. For measuring the viscosity of thickener A, the rotor No. for DVL-B type manufactured by Toki Sangyo Co., Ltd. was used. 4 for measuring the viscosity of thickener B. 1 was used. The viscosity of the thickener E was measured with a 1% aqueous solution of a cellulose-based water-soluble polymer using an LV Brookfield viscometer at a rotation speed of 12 rpm and 20 ° C. Thickener C is a value measured by HEAD, and thickener D is a value measured by Samsung.
Portland cement: Hayashi Cement, manufactured by Ube Mitsubishi Cement, Blaine specific surface area of 4,500 cm ² / g.
-Fine aggregate A: quartz sand, Takano No. 6 (Takano Shoji).
-Fine aggregate B: Silica sand, N70 (Ashiya).
Admixture: Blast furnace slag, manufactured by Kawasaki Steel Corporation, liberment, Blaine specific surface area 4,400 cm ² / g.
Expandable material: gypsum, manufactured by Asahi Glass Co., Ltd., hydrofluoric acid anhydrous gypsum, Blaine specific surface area 3,300 cm ² / g.
-Setting accelerator A: Potassium sulfate, manufactured by Ueno Pharmaceutical Co., Ltd.
-Setting accelerator B: Aluminum sulfate, manufactured by Daimei Chemical Co., Ltd., S150.
Thickener A: Marporose EMP30 (cellulose water-soluble polymer: hydroxypropylmethylcellulose (HPMC)), manufactured by Matsumoto Yushi Seiyaku Co., Ltd.
Thickener B: MX30000 (high viscosity type cellulose water-soluble polymer: hydroxyethyl methylcellulose (HEMC)), Matsumoto Yushi Seiyaku Co., Ltd., viscosity 30000 mPa · s.
Thickener C: 75HD30000 (cellulose-based water-soluble polymer: hydroxypropylmethylcellulose (HPMC)), manufactured by HEAD.
Thickener D: PMC30U (cellulose-based water-soluble polymer: hydroxypropylmethylcellulose (HPMC)), manufactured by Samsung.
Thickener E: Vermocol E431FQ (cellulose-based water-soluble polymer containing ethyl cellulose of high viscosity type: ethyl hydroxyethyl cellulose (EHEC)), manufactured by BASF Corporation, viscosity 30000 mPa · s.
・ Shrinkage reducing agent: Hibidan, manufactured by Takemoto Yushi Co., Ltd.
・ Fluidizing agent: Polycarboxylic acid-based water reducing agent (commercially available, for building materials).
-Antifoaming agent B: ADEKA company make, Adecanate B115F.
-Setting retarder: Sodium gluconate, manufactured by Tomita Pharmaceutical.
Resin powder: Nippon Synthetic Chemical Co., Ltd., Movinyl Powder DM200.
-Fiber: Polyester fiber, manufactured by Kyoto Textile Materials Co., Ltd., fiber length: 2 mm.

(Comparative Examples 1-4, Example 1)
The components listed in Table 1 were mixed to produce a self-leveling hydraulic composition. Table 2 shows the content ratio of components such as a setting accelerator among the components shown in Table 1 when the total of Portland cement and aggregate is 100 parts by mass. Table 3 shows the content of components such as a shrinkage reducing agent among the components shown in Table 1 when the total of the main components (Portland cement, aggregate, admixture and expansion material) is 100 parts by mass. Indicates the percentage. Next, while stirring the inside of a polyethylene beaker (2.0 liters) containing water (0.26 kg) with a mixer, the self-leveling hydraulic composition is 0.26 so that the water / self-leveling hydraulic composition ratio is 0.26. A product (1 kg) was added and kneaded for 3 minutes to obtain a hydraulic mortar. Each flow value, SL value, and flow rate at 20 ° C. and 5 ° C. of the obtained hydraulic mortar were measured, and the tendency of material separation was evaluated. The results are shown in Tables 4 and 5. Tables 6 and 7 show the difference and change rate of the SL value at room temperature of 20 ° C. and 5 ° C., and the difference and change rate of the flow rate, respectively.

※ ＨＰＭＣ：ヒドロキシプロピルメチルセルロース
ＨＥＭＣ：ヒドロキシエチルメチルセルロース
ＥＨＥＣ：エチルヒドロキシエチルセルロース

* HPMC: Hydroxypropylmethylcellulose HEMC: Hydroxyethylmethylcellulose EHEC: Ethylhydroxyethylcellulose

※ ＨＰＭＣ：ヒドロキシプロピルメチルセルロース
ＨＥＭＣ：ヒドロキシエチルメチルセルロース
ＥＨＥＣ：エチルヒドロキシエチルセルロース

* HPMC: Hydroxypropylmethylcellulose HEMC: Hydroxyethylmethylcellulose EHEC: Ethylhydroxyethylcellulose

  In Example 1, a hydraulic mortar was produced using a self-leveling hydraulic composition using a thickener containing a cellulose-based water-soluble polymer containing ethyl cellulose. In the hydraulic mortar of Example 1, as shown in Tables 4 to 6, there is no significant difference between Example 1 and Comparative Examples 1 to 4 regarding the flow value and SL value. However, as shown in Table 7, the difference in flow rate when the ambient temperature changed immediately after molding (L0) and 30 minutes after molding (L30) in Example 1 (5 ° C. and 20 ° C.) was compared. It is significantly smaller than Examples 1 to 4 (a self-leveling hydraulic composition using a thickener containing a cellulose-based water-soluble polymer that does not use ethyl cellulose). Therefore, the rate of change of the flow rate for each temperature unit is also significantly lower in Example 1 than in Comparative Examples 1 to 4. That is, the hydraulic mortar obtained using the self-leveling hydraulic composition of Example 1 has excellent fluidity (flow value and SL flow rate) and material even when the temperature conditions during construction change. While maintaining the separation resistance, it is easy to install and stably exhibits an excellent mortar flow rate.

  From the above, by using the self-leveling hydraulic composition of the present invention, it is possible to stably maintain high fluidity for a long time even when the temperature condition at the time of construction changes, so that good handling properties are obtained. It was clarified that a cured product obtained and having excellent horizontal level properties can be stably obtained, and a mortar cured product having excellent slurry fluidity and material separation resistance can be obtained. In particular, when the flow rate of the slurry is high, not only the efficiency at the time of construction is improved, but also has a positive effect on the homogenization of the hydraulic mortar and slurry at the place where the hydraulic mortar and slurry constructed from multiple places merge. It became clear. Therefore, by using the self-leveling hydraulic composition of the present invention for the level adjustment of the top end of the residential foundation concrete, it is possible to obtain excellent construction workability, high smoothness and high strength residential foundation concrete. It became clear that the structure can be formed in a short construction period.

  The self-leveling hydraulic composition used in the present invention comprises a main component comprising Portland cement, fine aggregate, an admixture and an expansion material, and a self-leveling hydraulic composition containing aluminum sulfate, a shrinkage reducing agent and a thickener. Since the composition is a thickener containing a cellulose-based water-soluble polymer using ethyl cellulose, the resulting hydraulic mortar is stable even when the temperature conditions during construction change. Maintain good fluidity for a long time. In particular, it not only improves the efficiency at the time of construction, but also has a positive effect on the homogenization of hydraulic mortar at the location where mortars constructed from multiple locations join as shown in Fig. 2, and the surface finish of the cured mortar is In addition to improving, there is an effect of greatly improving the variation in strength of the cured product.

  In the construction method of the foundation concrete structure for building of the present invention, by selecting and using the above self-leveling hydraulic composition, excellent construction workability can be obtained, smoothness is high, and high strength. It is possible to efficiently form a basic concrete structure for a building such as a house in a short construction period.

11: Ground 12: Crushed stone (consolidated layer)
13: Formwork 14: Reinforcing bar 15: Anchor bolt 16: Concrete for foundation (concrete)
17: Hardened mortar of self-leveling hydraulic composition 18: Corner part 21: Base concrete part 22: Surface of base concrete part 23: Formwork 24: Hydraulic mortar of self-leveling hydraulic composition 25: Hydraulic mortar Meeting point 32: Top end construction part A
34: Top end construction part B
40: Weir 50: Bucket 62: Hydraulic mortar at top end construction part A 64: Hydraulic mortar at top end construction part B

Claims (8)

Providing a form for forming a foundation concrete structure for a building;
Placing the reinforcing bars in the formwork;
A process of forming a base concrete part by placing concrete in a formwork;
A method for constructing a foundation concrete structure for a building, including a step of pouring and curing a hydraulic mortar prepared by kneading a self-leveling hydraulic composition and water on the upper surface of an underlying concrete part. ,
The self-leveling hydraulic composition is a self-leveling hydraulic composition comprising a main component comprising Portland cement, fine aggregate, an admixture and an expansion material, and aluminum sulfate, a shrinkage reducing agent and a thickening agent. ,
Fine aggregate is quartz sand, admixture is blast furnace slag fine powder, expansion material is gypsum,
The thickener is a thickener containing an ethyl hydroxyethyl cellulose-based water-soluble polymer ,
Construction method of foundation concrete structure for buildings. The main component of the self-leveling hydraulic composition consists of 100 parts by weight of Portland cement, 100 to 400 parts by weight of fine aggregate, 5 to 150 parts by weight of an admixture, and 3 to 30 parts by weight of an expansion material,
The thickener is made of a cellulose-based water-soluble polymer containing a high-viscosity type ethyl cellulose having a viscosity of 20,000 to 50,000 mPa · s at 20 ° C. in a 2% aqueous solution,
In a self-leveling hydraulic composition, for a total of 100 parts by mass of Portland cement and fine aggregate,
0.1 to 0.7 parts by mass of aluminum sulfate content,
The construction method of the foundation concrete structure for buildings of Claim 1 whose content of the cellulose water-soluble polymer containing the high viscosity type ethyl cellulose is 0.005-0.2 mass part.   The basic concrete structure for buildings according to claim 1 or 2, wherein the content of the shrinkage reducing agent in the self-leveling hydraulic composition is 0.1 to 3 parts by mass with respect to 100 parts by mass of the main components. Body construction method. The self-leveling hydraulic composition further comprises fibers,
The construction method of the foundation concrete structure for buildings according to any one of claims 1 to 3, wherein the fiber content is 0.01 to 5 parts by mass with respect to 100 parts by mass in total of the main components. The self-leveling hydraulic composition further comprises a fluidizing agent and an antifoaming agent,
The content of the fluidizing agent is 0.01 to 3 parts by mass with respect to 100 parts by mass in total of the main components
The construction method of the foundation concrete structure for buildings according to any one of claims 1 to 4, wherein the content of the antifoaming agent is 0.01 to 3 parts by mass with respect to 100 parts by mass of the total of the main components. .   The construction method of the foundation concrete structure for buildings of any one of Claims 1-5 in which a self-leveling hydraulic composition contains the other setting regulator except aluminum sulfate further.   The process of forming a foundation concrete part includes forming a primer hardening body layer by apply | coating and drying a primer on the upper surface of the hardened concrete, and forming a primer hardening body layer. The construction method of the foundation concrete structure for buildings of any one of Claims.   The construction method of a foundation concrete structure for buildings according to any one of claims 1 to 7, wherein the foundation concrete structure for buildings is for a one-story to three-story house.

Images