JPH0561423B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method of constructing a self-leveling material (hereinafter referred to as SL material) for finishing the floor of a structure. [Prior Art] As methods for finishing floors of structures, the following various methods are conventionally known. 1 Cement mortar finish; cement mortar or concrete (hereinafter referred to as base material)
A method of pouring cement mortar to a standard thickness of 25 mm and finishing the surface smooth with a metal trowel after hardening and curing. 2. Direct leveling of concrete (monolithic construction method): A method of finishing the surface of poured floor concrete to a smooth surface using a metal trowel, checking the level of water retention before the hardening of the poured floor concrete is completed. 3 Construction method using SL material: Level the poured base material with a wooden trowel, etc. After curing and curing, clean the surface of the base material, perform primer (adhesive) treatment, etc., then pour out the SL material and remove the dragon marks. A method of finishing it smooth using etc. 4 Recently, a construction method has been proposed in which SL material is poured before the hardening of the poured base material is completed. 4-1 After pouring concrete, a slurry of cement-based SL material is poured and hardened while a slight amount of breathing water remains on the concrete surface (Japanese Patent Application Laid-open No. 155434/1983); 4-2 After pouring concrete, Once the concrete has finished settling, the breathing water is forcibly removed and then poured onto the concrete surface.
Method of pouring SL material (Japanese Patent Application Laid-Open No. 60-223573)
and so on. [Problems to be Solved by the Invention] Method 1) involves placing the base material, curing it, and then finishing it with cement mortar, which requires two discontinuous steps and requires a long construction period. There are also disadvantages in that poor adhesion may occur on discontinuous surfaces, and that skilled plastering techniques are required to obtain surface smoothness. Method 2) requires a long time to finish the surface with a metal trowel after pouring the floor concrete to check the level of water drainage, and requires skill in leveling with a metal trowel to obtain a smooth surface. It is difficult to Method 3) also involves pouring the base material and curing it.
Two discontinuous steps are required to cast the SL material, which increases the required construction time.Additionally, it requires cleaning the surface of the hardened base material and applying a primer before pouring the SL material. However, it still has the disadvantage of being susceptible to poor adhesion. When using methods such as 4-1) or 4-2), in which SL material is poured before the concrete has completely hardened, it is necessary to check the water drainage of the concrete or force breathing water. Even if you simply remove the concrete and pour in the SL material, there is a problem that the integration of the concrete and SL material is insufficient and the adhesion is not sufficient. The purpose of the present invention is to shorten the construction time by continuously placing the base material and pouring the SL material, and to ensure the strength of the adhesive surface between the base material and the SL material, and to easily create a smooth floor surface. The purpose is to provide a floor finishing method that can be obtained. [Means for Solving the Problems] In order to improve the problems of the prior art, the present inventors conducted intensive research and roughened the surface of the base material that was cast as the floor of a structure before it had completely hardened. By doing so, we found that the subsequent pouring and spreading of the SL material and the integration of the base material and the SL material became possible, and based on this knowledge, we completed the present invention. In other words, the present invention relates to a self-leveling method in which a cement-based mortar or concrete is used as a base material, and a self-leveling material is poured over the base material to form a smooth floor surface, in which the base material is poured and leveled. Then, before the hardening of the base material is completed, the surface of the base material is roughened and the self-leveling material is poured on." The method of the present invention will be explained below. The method of the present invention is intended for floors of structures in which cement mortar or concrete is cast as a base material, and concrete includes lightweight concrete, crushed stone concrete, watertight concrete, prepacked concrete, ready-mixed concrete, and the like. Leveling after pouring the base material is normally done using a dragonfly or a wooden trowel, but in the method of the present invention, leveling with a dragonfly is sufficient. In the present invention, roughening the surface of the base material refers to creating fine lines evenly on the surface of the base material before completion of hardening by scratching the surface of the base material. The depth of the creases should be 0.1 mm or more, but it is not preferable to make them too deep from the viewpoint of workability and the size of the aggregate in the base material. Preferably 0.3-30
mm, more preferably 1 to 10 mm. Through this treatment, slag and uncured substances contained in cement and aggregate that separate and float to the surface after pouring are removed from the surface of the base material or rolled into the base material again. Furthermore, the surface area of the base material is increased. In order to roughen the surface of the base material in the method of the present invention, there are no particular restrictions on the shape or structure as long as it can fulfill the above-mentioned functions. , brooms such as palm brooms, scrubbers and brushes with hard bristles, and if the surface of the base material becomes hard, use hard protrusions made of metal, hard plastic, wood, bamboo, etc. It is preferable to use a large number of dragonfly-shaped or trowel-shaped tools, such as those disclosed in Japanese Patent Application Laid-Open No. 59-203157. The distance between the rod-like protrusions may be set as appropriate, but the diameter is preferably about 5 mm or less. If the distance between the protrusions is too wide, the scratching operation will have to be repeated many times, resulting in inefficiency. Moreover, if the diameter is too large, the efficiency of the roughening process will decrease. The thickness of the SL material layer is usually 10 mm, but depending on the finish of the surface of the base material, the actual thickness may be 5 to 30 mm, and locally it may be about 50 mm. When pouring the SL material onto the surface of the base material, the breathing water on the surface of the base material generated by material separation is pushed away from the starting point to the finishing point of pouring the SL material.
It is a good idea to provide a drainage port in advance at the point where the SL material has finished pouring to remove the breathing water, and then shut off the drain. In addition, when leveling the poured base material, a water guide groove of an appropriate width and depth should be created from the planned start point to the end point of the pouring of the SL material, such as the one shown in Figure 1. It is best to provide them at appropriate intervals so that the tributaries converge on the main stream. In the method of the present invention, commonly used gypsum-based or inorganic cement-based SL materials can be used. Gypsum-based SL materials include α hemihydrate gypsum, β
Gypsum-based materials such as hemihydrate gypsum and molded anhydrite, and inorganic cement-based SL materials include ordinary Portland cement, early strength Portland cement, ultra early strength Portland cement, moderate heat Portland cement, and special Portland cement. ,
Examples include those based on cements such as blast furnace cement, flyash cement, rapid hardening cement, and alumina cement. These base materials include river sand, mountain sand, sea sand, silica sand,
Various lightweight aggregates, slags, fly ashes and other fine aggregates can be mixed, and if necessary, dispersants, thickeners, and
Various additives such as antifoaming agents, expansion inhibitors, shrinkage inhibitors, and setting regulators can be blended. A polymer dispersion may be mixed into the SL material, or the polymer dispersion may be applied to the surface of the cast base material. The casting of SL material in the present invention means casting of a self-smooth slurry obtained by adding and kneading the above-mentioned SL material with appropriate water to give it fluidity. [Effect of the invention] After pouring the base material, it is possible to cast the base material without waiting for the hardening of the base material to complete, regardless of the presence or absence of breathing water.
Furthermore, since it is possible to continue pouring and spreading the SL material without any special pre-treatment to eliminate breathing water, it is possible to significantly reduce the time required for floor construction. It ensures the strength of the adhesive surface with the wood, and allows you to easily obtain a smooth floor surface. [Example] Hereinafter, the method of the present invention will be explained with reference to Examples and Comparative Examples. Examples: 1 to 10, Comparative Examples: 1 to 10 Formwork made of structural plywood with a thickness of 15 mm (dimensions:
600 x 600 x 300 mm), the concrete shown in Table 1 was poured to a thickness of 250 mm and leveled with a wooden trowel. The surface of the concrete in each formwork was roughened using a palm broom for 0.5 and 1 hour after pouring, and a nailed dragonfly for 3, 5 and 6 hours after pouring. Immediately after roughening, SL material slurry was poured to a thickness of 10 to 15 mm. A comparative example was also conducted in which the SL material slurry was poured without roughening treatment. Table 1 Mixture and physical properties of concrete used:

[Table] The SL material slurry used is shown in Table 2 or 3.
SL materials having the compositions shown in the table were kneaded at the sand ratio and water mixing ratio shown in Table 4, respectively.

【table】

【table】

[Table] After pouring and spreading the SL material, it was cured indoors at a temperature of 15 to 23°C, and the adhesive strength between the concrete and the SL material was measured 7 days and 28 days after the pouring. Table 5 shows the adhesive strength between the concrete and the SL material. The method for measuring adhesive strength is to
A cut was made from the wood layer to the concrete layer below, and measurements were taken using a Kenken-type tensile tester. All cases using the method of the present invention showed better adhesive strength than cases where roughening was not performed.

[Table] Example: 11 After erecting the cloth foundation formwork for a warehouse floor (5 x 10 m), concrete (slump: 16 cm) was poured to a thickness of 20 cm, and was leveled with a wooden dragonfly while using a width board. A groove with a depth of about 10 to 20 mm was formed in the shape shown in FIG. It took 1 hour and 30 minutes from pouring concrete to leveling and cutting grooves, and while continuing to roughen the concrete surface with a bamboo duster, we installed gypsum-based SL material "One-Two Floor" No. 1 (Nitto Chemical Industry Co., Ltd.) (manufactured by J.D.) was cast to an average thickness of 15 mm. The time required for spreading was 30 minutes. Three months after construction, the adhesive strength between the concrete and the SL material was measured at six locations on the floor using the same method as in the previous example. The measurement results were 22, 18, 25, 22, 23, 20 (average value: 22) Kg/cm ² , and all the fracture locations were in the concrete.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the water guide groove of the present invention. Explanation of symbols, 1... Floor subfloor material, 2... Water guide groove,
A... Point where SL material pouring starts, B... Place where SL material pouring ends, 〓 or →... Shows the outline (only a portion) of the direction in which SL material is poured.

Claims (1)

[Claims] 1 In the self-leveling construction method, where cement-based mortar or concrete is used as a base material and a self-leveling material is poured over the base material to form a smooth floor surface, after the base material is poured and leveled,
A method for applying a self-leveling material, which comprises roughening the surface of the base material and pouring the self-leveling material on the surface before the hardening of the base material is completed.