JPH0432907B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a self-leveling method in which a slurry containing various types of gypsum, Boltland cement, and other hydraulic cements is poured onto the subfloor of a structure and then hardened to form a horizontally smooth floor surface. . (Conventional technology) As is well known, the self-leveling method is a method in which a slurry containing hydraulic cement (hereinafter also simply referred to as slurry) is poured into the subfloor of a structure and allowed to flow naturally. A construction method that forms a horizontal surface with good level accuracy by hardening it (also called the poured floor construction method).
It is. In other words, this construction method allows slurry poured into the sub-floor to flow naturally under the action of gravity while it still retains sufficient fluidity to form a horizontally smooth construction surface (new floor surface). From this perspective, in this construction method,
Once the slurry has been poured onto the subfloor, avoid any situation that may disturb the slurry as much as possible.
It is said that it is preferable to leave it in the poured state (let it stand still) from the viewpoint of forming a floor surface with good level accuracy. (Problems to be Solved by the Present Invention) Therefore, in this construction method, when the slurry is poured onto the subfloor, it is possible that the slurry used was not appropriate, for example, the composition of the slurry was not appropriate. Even if it is found that there is an excess or deficiency in the amount of raw materials used, and it becomes necessary to add specific raw material components to the slurry after pouring to optimize the slurry, there is no need to worry about this. Without implementing such optimization measures,
The reality is that it is left as is. This is because even if it is possible to optimize the slurry by adding raw materials to the slurry after pouring, adding raw materials to a slurry that has already hardened and whose viscosity is increasing is difficult. Disturbances are newly formed (or are being formed) due to the natural flow of the slurry.
This is due to the fear that it will have a negative impact on the floor surface, impairing the expression of good level accuracy (improving the finished flatness of the newly formed floor surface). Therefore, in the above case, a problem arises in that the construction results are unsatisfactory or even fail. (Means for Solving the Problems) As a result of various studies to solve these conventional problems, the inventors of the present invention have found that even when raw material components are added to the slurry after pouring, the subsequent addition is to the slurry. If this is done while the slurry is still fluid, and the slurry is stirred and mixed to homogenize after adding the raw materials, the level of precision on the construction surface will not be impaired in any way, and the slurry will be Surprisingly, in this case, it is not only possible to optimize the slurry, but also to pour the appropriate slurry onto the subfloor from the beginning, and then to improve the level accuracy of the construction surface. In order to improve this, we have discovered that the level accuracy of the construction surface can be significantly improved compared to when the slurry surface is leveled using a plasterer's dragonfly or trowel according to the conventional method, and we have arrived at the present invention. That is, the present invention provides a self-leveling construction method in which a slurry containing hydraulic cement is poured onto the subfloor of a structure to form a smooth floor surface.
After pouring the slurry onto the sub-floor, while the slurry is still in a fluid state, the slurry is mixed with hydraulic cement, aggregate, dispersant, thickener, etc.
It is characterized by post-adding one or more of slurry raw materials such as an expanding agent, an expansion inhibitor, a shrinkage inhibitor, an antifoaming agent, a setting regulator, and water, and then stirring and mixing to homogenize the slurry. Self-leveling construction method. ”. To explain the motivation behind the present invention, the present inventors previously disclosed in Japanese Patent Application No. 74032/1983 (Japanese Unexamined Patent Publication No. 2103157/1983) that in the self-leveling method, slurry is applied to the subfloor. After pouring, a film with properties different from the internal slurry forms on the surface of the slurry within a short time, but while the slurry is still in a fluid state, the slurry is stirred and mixed to homogenize it. It has been disclosed that when such treatment is performed, the level accuracy of the construction surface can be significantly improved compared to when such treatment is not performed. The present invention has been made based on this fact, and as mentioned above, it is not only effective to disturb the slurry under certain conditions after pouring the slurry on the subfloor, but it is even more effective. Since an unexpected favorable effect was obtained, it was attempted to optimize the slurry in addition to the above-mentioned effect by post-adding raw material components to the slurry prior to the disturbance. The hydraulic cement used in the present invention is gypsum and inorganic cements that have been conventionally used in self-leveling construction methods. Examples of gypsum-based cement include α-hemihydrate gypsum, β-hemihydrate gypsum, type anhydrite, etc. Examples of inorganic cements include ordinary Portland cement, early strength Portland cement, ultra early strength Portland cement, medium Portland cement, special Portland cement, blast furnace cement, fly ash cement, rapid hardening cement, alumina cement, granulated blast furnace slag, Examples include blast furnace slag and fly ash. During construction, only these cements may be used, but usually these cements are combined with aggregate,
For example, river sand, mountain sand, sea sand, silica sand, various lightweight aggregates, various slags, and other aggregates are mixed, and if necessary, various dispersants and thickeners commonly used in this type of self-leveling cement are added. Additives such as a foaming agent, a swelling agent, an expansion inhibitor, a shrinkage inhibitor, an antifoaming agent, and a setting regulator are added. Therefore, the slurry containing hydraulic cement in the present invention refers to a slurry obtained by adding appropriate water to the above-mentioned cement alone or a mixture thereof with one or more types of aggregate and additives and kneading the same. say. Examples of the preparation of the slurry containing the above-mentioned hydraulic cement and the additives added to the slurry in the present invention are as follows. Γ Dispersant: Alkylaryl sulfonate type, aromatic polycyclic condensate sulfonate type, polyol type,
Melamine formalin resin sulfonate type, higher polyhydric alcohol type, oxyorganic acid salt type, lignin type or polyoxyethylene alkyl ether type. Γ Thickener: Carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, polyvinyl alcohol, polyethylene oxide or natural polymeric polysaccharide. Γ Expansion agent: Calcium sulfoaluminate, calcium oxide or iron powder. Γ expansion inhibitor...borax, potassium sulfate, sodium citrate, Rothsiel's salt, slaked lime, succinic acid or maleic acid. Γ contraction inhibitors...urea, methylurea, ethylurea,
Acetamide or calcium cyanamide. Antifoaming agent: silicone-based, ethylene oxide-propylene oxide-based. Γ Coagulation regulator...polypeptone, amino acid derivative,
Citric acid, glycolic acid, sucrose, potassium sulfate, Glauber's salt, aluminum sulfate, potassium hydroxide, calcium oxide, sodium aluminate, potassium aluminate, sodium silicate, potassium fluoride, sodium fluoride, calcium chloride, potassium carbonate, sodium carbonate, Sodium hydroxide or potassium hydroxide. The subfloor of the structure to be constructed in the present invention is the so-called foundation of the structure,
For example, poured concrete, PC concrete,
New or existing materials such as ALC lightweight concrete, cement mortar, wood wool cement board, and wood chip cement board can be used as examples. In the present invention, after the slurry containing the hydraulic cement is poured onto the subfloor of such a structure, and while the slurry is still in a fluid state, the above-mentioned hydraulic cement, One or more of the slurry raw materials such as aggregates, dispersants, thickeners, swelling agents, expansion inhibitors, shrinkage inhibitors, defoamers, setting regulators and water are post-added. At this time, the slurry raw material to be added later is appropriately selected depending on the properties of the poured slurry. For example, if the fluidity of the slurry is poor, there are various reasons for this, but usually water, dispersant, etc. are insufficient due to the composition, so these are added afterward.On the other hand, if floating water occurs in the slurry, Since water is usually in excess, raw material components other than water (cement, dispersant, aggregate, and other components) are added afterwards. In addition, in this type of construction method, if Portland cement or similar cements are used as the hydraulic cement, even if a slurry of the appropriate composition (from the fluidity point of view) is poured onto the subfloor from the beginning, Cracks may appear on the floor surface after the slurry hardens, which has been considered a problem in the past, but in such cases, adding a quick hardening agent to the slurry after pouring at an appropriate time can solve this problem. can be prevented. In the self-leveling method, as mentioned above, after the slurry is poured onto the subfloor, a film with properties different from the inside is formed on the slurry surface within a short time (usually immediately), but it is necessary to stir the slurry. When homogenized by mixing, a favorable effect of improving the level accuracy of the construction surface can be obtained. Therefore, in the present invention, after adding the slurry raw material to the slurry after pouring,
The slurry is stirred and mixed using appropriate equipment to homogenize it. At that time, it goes without saying that the raw material components added later are also stirred and mixed to homogenize the slurry as a whole. The equipment used at this time may be of any shape or structure as long as it can stir and mix the slurry and post-added raw material components to homogenize the cellarry, but it may have any shape or structure as long as it can achieve the desired purpose and effect. From the viewpoint of economy, workability, etc., it is desirable to use one that is as simple in structure and easy to use as possible. In this way, as a device, for example, a conventional plastering dragonfly or trowel as shown in Figures 1 to 4 with many rod-shaped protrusions attached, or a device with side branch protrusions attached to the rod-shaped protrusions, or Examples include those having similar shapes. Below, some of these devices will be explained with reference to the drawings. Figure 1 A is a plastering iron with a number of rod-shaped protrusions attached at right angles to the substrate. As for metal,
Plastic, rubber, wood, bamboo, etc. are used. If the length of the rod-shaped protrusion is too short, the base of the iron will come into contact with the slurry during work, worsening work efficiency, so the length of the rod is usually at least twice the thickness of the slurry being poured, preferably at least twice as long. do. The tip of the rod should be rounded to allow for smooth stirring operations.If the rod is too thin, it will not have sufficient strength, and if it is too thick, it will unnecessarily disturb the slurry, so the diameter of the rod is usually around 1 to 5 mm. Make it. If the distance between the bar-like protrusions is too narrow, the slurry will move too much during work, and if it is too wide, the slurry will not be stirred and mixed sufficiently.
Usually 2-10cm. The rods may be arranged in any manner such as random, aligned, or staggered on the substrate, but usually arranging them in 1 to 5 rows on the substrate in a staggered manner provides the best stirring efficiency. If the number of rows exceeds 5, the workability will deteriorate. B in Fig. 1 is a rod-shaped protrusion in A with side branch protrusions attached, and it is expected that the stirring effect will be better than in the case where A is used. 1C is an example in which a mesh plate is used in place of the substrate in A. Figures 2 to 2 are examples in which a rod-shaped protrusion is applied to a plasterer's dragonfly, and O in Figure 3 is an example in which a mesh rotating frame is attached instead of the rod-shaped protrusion. . In addition, the holes in Fig. 3 are made by attaching rod-like protrusions at intervals of 2 to 5 cm along the diameter at the bottom of a wooden or metal disk or ring-shaped frame, or using plate-like protrusions instead of sticks. This is an example of a case where many objects are attached. Furthermore, ``way'' in FIG. 4 is an example of a shape similar to a rake for cleaning a garden, a rake for farming, or the like. In addition, in the above-mentioned dragonfly-shaped or trowel-shaped device to which a rod-shaped projection or a rod-shaped projection with a side branch is attached, a plate-shaped projection with a width of 0.5 to 10 cm and the same height as the projection is used instead of these projections. You can also attach multiple things. At this time, it goes without saying that the intervals between the plate-like protrusions, the arrangement, etc. of the plate-shaped protrusions should be adjusted to suit the stirring and mixing of the slurry. Next, how to use these devices will be explained. Normally, a film is formed on the slurry surface immediately after construction. Therefore, after pouring the slurry onto the subfloor, immediately after adding the slurry raw material, or at an appropriate time while the slurry is still in a fluid state, use the above-mentioned dragonfly or trowel.
Each rod-like protrusion or plate-like protrusion is held perpendicular to the slurry surface and moved linearly or circularly over the entire area of the slurry layer, moving throughout the slurry. When using a dragonfly with a reticulated rotating frame attached, the rotating frame is rolled and moved in the slurry all over the construction surface in the same manner as above. Furthermore, when a device such as a disk or ring-shaped frame with a rod-shaped protrusion or a plate-like protrusion attached is used, the same process as above is performed while rotating the disk etc. with an appropriate power. Note that, if necessary, the dragonfly, trowel, etc. mentioned above can be towed by power, or can be towed while applying power vibrations. By performing such treatment on the slurry that has been poured onto the subfloor and to which the slurry raw material has been subsequently added, the slurry and the post-added slurry raw material are stirred and mixed, and the slurry is homogenized. In carrying out the present invention, such treatment can be repeated not only once but as many times as long as the slurry retains its fluidity. Also, depending on the type of slurry used,
After the treatment, a film may be formed on the slurry surface again, so in such a case, the treatment may be repeated until no surface film is formed. Furthermore, in the present invention, even when the slurry viscosity increases, the slurry can be sprinkled with water and the process can be repeated, if necessary. Next, the present invention will be specifically explained with reference to examples. In each of the following examples, all parts simply represent weight. (Example) Example 1 40 parts of tap water was charged into a high-speed electric mixer and while rotating, 0.3 part of Mighty FD (trademark, manufactured by Kao Soap Co., Ltd.) was added as a dispersant and 0.2 part of carboxymethyl cellulose (CMC) as a thickener. , as an antifoaming agent
A pre-mixed mixture of 0.02 parts of KM73 (trademark, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.2 parts of Pufftard P-11 (trademark, manufactured by Ajinomoto Co., Inc.) as a setting regulator was added, and then α 80 parts of mold hemihydrate plaster;
After adding 20 parts of β-type hemihydrate gypsum and 100 parts of river sand of 20 mesh passes as aggregate, they were mixed for 3 minutes to prepare a slurry for pouring. The flow value of the slurry immediately after kneading is 203 mm (when a PVC cylindrical frame with a diameter of 50 mm and a height of 51 mm is filled with slurry, placed on a glass plate, and the cylindrical frame is pulled up vertically, the slurry spreads in a circular shape on the glass plate). (hereinafter the same shall apply) and had suitable fluidity for casting. The slurry was left in the mixer for 45 minutes and then poured to a thickness of 5 mm onto each of the four compartmented test beds (mortar beds) that had been previously treated with an acrylic primer. (The area of each section was 2 m ² ) 1st section (control example) The self-leveling properties of the poured slurry were poor, and the surface was uneven. The flow value of this slurry was 178 mm. 2nd section (control example) After pouring the slurry, width 10cm x length 500mm
× Mixing was carried out by stirring using a stirring tool in which iron rods of length 5 cm and diameter 2 mm were driven in three rows at 30 mm intervals in a zigzag pattern on a 10 mm thick wooden board. As a result, the slurry surface became smooth, but some scratches still remained. Third section (method of the present invention) After the slurry is poured, 0.1 part of Melment L-10 (trademark, liquid product manufactured by Showa Denko K.K.) as a dispersant is sprayed uniformly over the entire surface of the slurry using a horticultural sprayer. At the same time, the slurry was thoroughly stirred using the stirring tool described above to homogenize it. After stirring, a portion of the slurry was taken out and the flow value was measured, and the result was 198 mm. 4th section (method of the present invention) After pouring the slurry, spray 0.5 parts of tap water evenly over the entire surface of the slurry with a gardening spray, and at the same time stir the entire slurry thoroughly using the same stirring tool as above. homogenized. After stirring, a portion of the slurry was taken out and the flow value was measured.
It was 209mm. After the slurry poured into each section has hardened, the flatness (level accuracy) of the surface finish is evaluated.
Results measured according to JASS-5T-604 (Test method for flatness of finished concrete) and 7-day compressive strength of cured product (40 x 40 x 160 mm square bar) (compressive strength on the 7th day after curing) The results of the measurements are shown in Table 1.

[Table] As is clear from Table 1, according to the present invention, the difference in finished flatness is significantly improved. Example 2 46 parts of tap water was charged into a high-speed electric mixer and while rotating, 0.4 parts of 7-7500 (trademark manufactured by Nippon Zeon Co., Ltd.) was added as a dispersant and Kelzan (trademark) was added as a thickener.
Sansho Co., Ltd.) 0.1 part, silicone as an antifoaming agent
A mixture of 0.02 parts of KM73 (trademark, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.1 parts of polypeptone (reagent) as a setting regulator was added, followed by 100 parts of alpha hemihydrate gypsum as hydraulic cement and 100 parts of silica sand as aggregate. A slurry for pouring was prepared by kneading for 3 minutes. The flow value of the slurry immediately after mixing is 233
It was warm in mm. The subfloor for pouring (test floor) was a mortar bed that had been treated with an ethylene-vinyl acetate primer in advance, and consisted of three sections of 2 ^m2 each. The slurry was poured into each section to a thickness of 10 mm. 1st section (control example) Floating water was generated in the slurry after pouring and spreading. 2nd section (method of the present invention) Add 5 silica sand (No. 6) to the slurry after pouring.
Immediately, the entire surface was sufficiently stirred using the same stirring tool used in Example 1 to completely mix the silica sand. The flow value of the slurry after treatment was 208 mm. 3rd section (method of the present invention) Immediately after pouring the slurry, CMC0.05
A portion of the slurry was spread with powder over the entire surface of the slurry, and the entire surface was sufficiently stirred using the same stirring tool used in Example 1 to completely mix the slurry. The flow value of the slurry after treatment was 213 mm. For each section, after the slurry had cured, the presence or absence of efflorescence on the surface was measured, and three days after curing, vinyl floor tiles were adhered to the cured surface using an epoxy adhesive, and the surface adhesive strength was measured two weeks later. . The results are shown in Table 2.

[Table] As is clear from Table 2, according to the present invention, efflorescence is prevented and the surface adhesive strength with vinyl floor tiles is also improved. Example 3 55 parts of tap water was charged into a high-speed electric mixer, and while rotating, Melment F-10 (trademark) was added as a dispersant.
0.5 parts (manufactured by Showa Denko Co., Ltd.), 0.2 parts of Hymetolose (trademark, manufactured by Shin-Etsu Chemical Co., Ltd.) as a thickener, and 0.2 parts of SN-Deformer 14-HP (trademark, manufactured by Sannopco Co., Ltd.) as an antifoaming agent.
A pre-mixed mixture of 0.1 part (Made in Japan) and 1.0 part potassium alum as a setting regulator was added, followed by 60 parts of molded anhydrite as hydraulic cement, 40 parts of fly-ash cement and 100 parts of sea sand as aggregate.
A slurry for pouring was prepared by kneading for 3 minutes. The flow value of the slurry immediately after mixing is 228
It was warm in mm. The base floor (test floor) for pouring is a mortar bed that has been treated with an acrylic primer in advance.
There were 3 sections of ² m each. The slurry was poured into each section to a thickness of 10 mm. 1st section (control example) Floating water was generated in the slurry after pouring and spreading. Second Section (Comparative Example) One hour after the slurry was poured, the entire surface of the slurry was thoroughly stirred using the same stirring tool as used in Example 1. As a result, floating water disappeared. Third section (method of the present invention) After pouring the slurry, powder mixed with 10 parts of fly ash cement and 10 parts of sand was spread over the entire surface of the slurry, and using the same stirring tool as used in Example 1. The entire surface was thoroughly stirred to ensure complete mixing.
The flow value of the slurry after treatment was 199 mm. After the slurry poured into each section hardens, we check the presence or absence of efflorescence on the surface, check the 7-day compressive strength of the cured product (40 x 40 x 160 mm square rod), and after 7 days, glue the vinyl floor tiles with epoxy adhesive. The results of measuring the surface adhesive strength after two weeks were as follows.

[Table] Example 4 50 parts of tap water was charged into a high-speed electric mixer, and while rotating, Melment F-10 (trademark) was added as a dispersant.
0.5 parts (manufactured by Showa Denko Co., Ltd.), 0.2 parts of Hymetolose (trademark, manufactured by Shin-Etsu Chemical Co., Ltd.) as a thickener, and SN Defomer 14-HP (trademark: Sannopco) as an antifoaming agent.
Co., Ltd.) and 10 parts of Denka CSA (trademark, made by Denki Kagaku Kogyo Co., Ltd.) as an expanding agent were added in advance, followed by 100 parts of Class B blast furnace cement as hydraulic cement and 100 parts of B-type blast furnace cement as aggregate. 100 parts of river sand (20 mesh pass product) was added and kneaded for 3 minutes to prepare a slurry for pouring. The flow value of this slurry immediately after kneading was 224 mm. The base floor (test floor) for pouring is a mortar bed that has been treated with an acrylic primer in advance.
There were 3 sections of ² m each. The slurry was spread over each section to a thickness of 10 mm. 1st section (control example) Floating water was generated in the slurry after pouring and spreading. Second section (control example) One hour after pouring the slurry,
The entire surface of the slurry was sufficiently stirred using the same stirring tool used in Example 1 to completely homogenize the slurry. As a result, the floating water disappeared. Third section (method of the present invention) After the slurry was poured, 1.0 part of aluminum sulfate powder was sprinkled over the entire surface of the slurry as a coagulation regulator, and the slurry was thoroughly stirred with the same stirring tool used in Example 1. Mix thoroughly. The curing time, the presence or absence of efflorescence on the surface of the cured product, and the presence or absence of cracks were measured for the slurry poured into each section, and the results were as shown in Table 4.

[Table] As is clear from Table 4, according to the present invention, cracks in the cured product can be prevented. Example 5 55 parts of tap water was charged into a high-speed electric mixer, and while rotating, 0.7 parts of Melment F-10 (trademark, manufactured by Showa Denko K.K.) was used as a dispersant, and Hymetrose (trademark, manufactured by Shin-Etsu Chemical Co., Ltd.) was added as a thickener. Co., Ltd.), 0.1 part of SN Defomer 14-HP (trademark, made by San Nopco Co., Ltd.) as an antifoaming agent, and 10 parts of Onoda Expan (trademark, made by Onoda Cement Co., Ltd.) as an expanding agent. Then, 100 parts of ordinary Portland cement as a hydraulic cement and 100 parts of sea sand (20 mesh pass product) as an aggregate were added and kneaded for 3 minutes to prepare a slurry for pouring. The flow value of this slurry immediately after mixing is 178mm.
It was hot. The subfloor for pouring (test floor) was a mortar bed that had been treated with an ethylene-vinyl acetate primer in advance, and consisted of three sections of 2 m ² each. The slurry was poured into each section to a thickness of 10 mm. First section (control example) The surface of the slurry after pouring was leveled with a plasterer's dragonfly, but unevenness occurred. Second section (control example) The slurry after pouring was stirred and mixed using the same stirring tool as used in Example 1. Third section (invention) After pouring the slurry, an aqueous solution was prepared by dissolving 1 part of sodium aluminate as a setting control agent in 6 parts of water, and was removed with a horticultural spray, at the same time as in Example 1. The entire surface of the slurry was thoroughly stirred and mixed using the stirring tool used. Table 5 shows the results of measuring the curing time, the finished flatness of the newly formed floor surface (level accuracy), and the presence or absence of cracks on the surface of the cured product for the slurry poured into each section.

[Table] As is clear from Table 5, according to the present invention, it is possible to improve the finished flatness of a newly formed floor surface and at the same time prevent the occurrence of cracks. (Effects of the Invention) Next, the effects of the present invention will be explained. For example, when slurry poured onto a subfloor has poor fluidity,
If a sufficiently smooth surface is not formed on the slurry surface, the fluidity of the slurry can be increased by post-adding water or a dispersant to impart sufficient self-smoothness to the slurry. In addition, conventionally, after pouring the slurry, the slurry still maintains fluidity even after a certain period of time has passed, but if the surface has stiffness that cannot be defoamed, foaming occurs, and after curing, This may cause raised foam marks. In such cases, it is possible to improve the fluidity of the slurry and promote defoaming by adding water or a dispersant later while the slurry still maintains its fluidity. The agent can be added later, and complete defoaming can be achieved by stirring after adding these raw materials. Furthermore, if there is too much mixing water, aggregate settling, breathing, etc. that occur in the poured slurry will cause unevenness, efflorescence, cracks, etc. on the floor surface after hardening. Post-addition of hydraulic cement, sand, thickener, etc. can prevent aggregate settling, breathing, etc., and can prevent unevenness, efflorescence, cracks, etc. after hardening. Furthermore, as mentioned above, when inorganic cement materials such as ordinary Portland cement, early strength Portland cement, blast furnace cement, fly ash cement, etc. are used as hydraulic cement in this type of construction method, the poured slurry It had the disadvantage of poor self-smoothness and cracks on the floor surface after curing. However, even when such a cement is used, according to the present invention, the self-smoothness of the slurry can be improved by stirring and mixing the slurry while it is still in a fluid state after pouring to make the slurry homogeneous. It can improve the level accuracy and prevent the occurrence of cracks on the floor surface after hardening.
After casting, cracking can be prevented by post-adding a curing agent to the slurry and curing it in a short period of time (usually from several minutes to 6 hours, preferably from several minutes to 3 to 4 hours). As mentioned above, according to the present invention, it is possible to modify the physical properties of the slurry even after it has been poured onto the subfloor, whereas in the past, after the slurry has been spread on the subfloor, it was only possible to modify the physical properties of the slurry for plastering. The main part of the repair work was to improve the level accuracy of the floor surface using dragonfly and trowels, and this required skilled plastering techniques. In fact, it was completely impossible to modify the physical properties of the slurry once it had been poured in terms of its composition. Therefore, conventionally, after the poured slurry has hardened, that is, the day after it is poured, uneven surfaces are adjusted by sanding, finishing is done by squeezing with hard dough, and foaming marks and pinholes are repaired. However, according to the present invention, such repair work is unnecessary, and it is possible to save labor and shorten the period required for construction, resulting in a large economic effect. Furthermore, the problems of poor self-smoothness and generation of cracks after curing, which have traditionally been the biggest drawbacks of cement-based self-leveling materials, can be solved at once by the present invention, as mentioned repeatedly.

[Brief explanation of drawings]

In the drawings of FIGS. 1 to 4, the figures indicated by the symbols I to Y each represent slurry stirring devices preferably used in the present invention.

Claims (1)

[Scope of Claims] 1 In a self-leveling construction method in which a slurry containing hydraulic cement is poured onto the sub-floor of a structure to form a smooth floor surface, after the slurry is poured onto the sub-floor, the slurry is still fluid. While maintaining the slurry, slurry raw materials such as hydraulic cement, aggregates, dispersants, thickeners, swelling agents, expansion inhibitors, shrinkage inhibitors, antifoaming agents, setting regulators, and water are added to the slurry. A self-leveling method characterized by post-adding one or more of the following, followed by stirring and mixing to homogenize the slurry. 2 Hydraulic cement is α hemihydrate gypsum, β hemihydrate gypsum,
Type anhydrite, ordinary Portland cement, early strength Portland cement, ultra early strength Portland cement, moderate heat Portland cement, special Portland cement, blast furnace cement, fly ash cement, rapid hardening cement, alumina cement,
The method according to claim 1, wherein the method is one or more of granulated blast furnace slag, blast furnace slag, and fly ash. 3. The slurry containing hydraulic cement is selected from the group consisting of hydraulic cement alone or together with aggregate, dispersant, thickener, swelling agent, expansion inhibitor, shrinkage inhibitor, antifoaming agent, and setting regulator. The method according to claim 1, which is an aqueous slurry of a mixture with one or more selected additives.