JPS632909B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a cement-based unevenness adjusting agent. Conventionally, for secondary cement products such as concrete exterior walls, interior partition walls, floorboards, etc., in order to give the surface smoothness, fresh concrete was poured into formwork and waited for water to float (breathing). The surface is smoothed with a metal trowel, but the waiting time for this breathing is long, so if fresh concrete is poured during the day, the troweling work after breathing has to be done at night. There was a big inconvenience. Cement mortar or cement paste is also poured into a floor or other tile base, and then smoothed using a wooden or metal trowel. This type of work is difficult as it increases the number of man-hours, and if the ratio of water is increased in order to facilitate this troweling work, there is the problem that cracks or floating phenomena may occur on the formed surface later on. It was hot. The inventors of the present invention have conducted extensive research in order to solve such conventional inconveniences and problems, and have completed the following cement-based unevenness adjusting agent. That is, in the present invention, cement mortar or cement paste contains, per 100 parts by weight of cement,
0.01 to 10 parts by weight of nonionic cellulose ether, 0.01 to 10 parts by weight of a water reducing agent whose main component is at least one selected from alkylaryl sulfonates, sulfonates of water-soluble melamine-formalin resins, and 0.05 to 5 parts by weight of antifoaming agent. The present invention relates to a cement-based unevenness adjusting agent in which parts by weight are added. When the cement-based unevenness adjusting agent of the present invention is poured onto the surface of ready-mixed concrete after pouring, for example, it spreads uniformly on the surface, and there is no need for leveling work with a metal trowel or the like, and moreover, it does not cause breathing. This provides the advantage of significantly streamlining the work, as it produces a smooth finished surface without any scratches. Also, in the case of floors, a smooth finished surface can be formed by simply pumping the unevenness adjusting agent with a pump, etc. without the need for smoothing with a trowel, so it can be used for tiles (plastic tiles, wood tiles, etc.), carpet bases, etc. is very easily obtained and can also be used as a base for paint. That is, if the unevenness adjusting agent of the present invention is used, (1) Even though no leveling work is performed,
The surface is surprisingly smooth with no pinholes. (2) There is no need to wait for breathing and level the trowel as in the past, greatly increasing work efficiency. (3) Excellent adhesion to the underlying concrete and sufficient strength. (4) A smooth finished surface will not cause any cracks or lifting later on. (5) If a curing accelerator is used, it is efficient because it cures in a short time, and the curing time can be controlled. This brings about several notable advantages. The present invention will be explained in detail below. As the cement used in the present invention, various conventionally known hydraulic cements such as Portland cement (normal, early strength, ultra early strength, etc.), slag cement, and alumina cement can be used. On the other hand, examples of nonionic cellulose ethers include methylcellulose (MC), hydroxypropylmethylcellulose (HPMC), hydroxyethylmethylcellulose (HEMC), hydroxyethylethylcellulose (HEEC), hydroxyethylcellulose (HEC), and hydroxypropylcellulose (HPC). used. Further, in the present invention, a water reducing agent selected from those containing an alkylaryl sulfonate as a main component and those containing a sulfonate of water-soluble melamine formalin resin (methylol melamine) as a main component is used. Among these, water-soluble melamine-formalin resin is particularly preferred. Examples of antifoaming agents used in the present invention include polyoxyethylene-polyoxypropylene block copolymers resistant to alkalinity, special nonionic compounds, higher alcohols, and tributyl phosphate. The cement-based unevenness adjusting agent of the present invention can be obtained by adding predetermined amounts of the above-mentioned nonionic cellulose ether, specific water-reducing agent, and antifoaming agent to cement mortar or cement paste obtained from the above-mentioned cement. . By using these three types of additives in combination, it is possible to obtain high fluidity, low material separation and laitance, and a smooth surface without pinholes. Non-ionic cellulose ether alone
Even if some effects can be achieved in terms of material separation and laitance, fluidity is poor due to viscosity, so
The water/cement ratio increases, strength decreases, shrinkage cracks increase, and pinholes tend to form on the surface due to air entrainment. However, by simultaneously adding and containing a specific water reducing agent and an antifoaming agent, this difficulty can be overcome and the remarkable effects described above can be obtained. In order to more effectively achieve the various effects of the present invention, it is necessary to reduce water by adding 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight of nonionic cellulose ether per 100 parts by weight of cement to cement mortar or cement paste. 0.01 to 10 parts by weight of the agent, preferably 0.1 to 5 parts by weight, and 0.05 to 10 parts of the antifoaming agent.
It is necessary to add 5 parts by weight, preferably 0.1 to 3 parts by weight. In addition, there is no problem in further blending a curing accelerator, a filler, etc. into the unevenness adjusting agent obtained in this way. By incorporating a curing accelerator, it is possible to prevent the delay in setting time that is generally caused by adding a nonionic cellulose ether, and by adjusting the amount of the curing accelerator, the curing time can be controlled. Examples of the hardening accelerator include basic calcium chloride, baked bean paste, sodium aluminate, silicofluoride, carbonate, organic acids and their salts, and these are 0.1 to 5% per 100 parts by weight of cement.
It is preferable to add 0.2 to 3 parts by weight, more preferably 0.2 to 3 parts by weight. Furthermore, examples of fillers include calcium carbonate, clay, silica, and inorganic or organic fibrous substances. Next, specific examples of the present invention and comparative examples will be given. However, in all cases, the following ready-mixed concrete was used. (Ready-mixed concrete) Early strength Portland cement 100 parts River sand (3 mm or less) 196〃 Asanolite (lightweight aggregate, manufactured by Nippon Cement)
172〃 Paritsuku A (curing accelerator, manufactured by Fujisawa Pharmaceutical) 1.3〃 Water 44〃 (Parts indicate parts by weight, the same applies below) [Dimensions of formwork to pour fresh concrete] Width 300mm, length 500mm, height 100mm Implementation Example 1 Various tests were conducted on the following four types of mortar.

[Slump test]

When the slump value (cm) was measured for each mortar when the proportion of water was varied and expressed in a graph, the results shown in FIG. 1 were obtained. However, a small slump cone measuring 50 x 100 x 150 mm was used. Mortar No. 1... Curve 〃 No. 2... 〃 〃 No. 3... 〃 〃 No. 4... 〃 As can be seen from this result, the cement-based unevenness adjusting agent of the present invention (mortar No. 1) is extremely liquid. [Smoothness, material separation, pinholes, cracks, and laitance tests] Pour fresh concrete into formwork (thickness: 100 mm)
mm), then apply mortar No. 1 (water content) on this side.
Mortar No. 2 (with a water content of 60 parts), Mortar No. 3 (with a water content of 63 parts), and Mortar No. 4 (with a water content of 65 parts). The mortar was poured to a thickness of 30 mm and cured without troweling. After 28 days, the surface smoothness, pinholes, cracks, laitance, and material separation (the state of the cross section of the mortar was observed. ) was investigated. However, for mortar No. 4, mortar was poured and the surface was smoothed using a metal trowel. The results were as shown in Table 1. Surface smoothness: Judging with the naked eye according to the following criteria. A...Very smooth B...Smooth (not as good as A, but no problem in practical use) C...Slightly uneven D...Pinholes with many uneven surfaces: Pinholes that occur on the surface Judgment was made with the naked eye. A: No cracks B: Some cracks C: Many cracks: Judging with the naked eye. A...No eyelashes B...Several spots C...Many laitances: Determined by catching the surface with a spatula. A: No eyelashes B: A little bit C: A lot of material separation: The cross section of the mortar was observed and judged based on the degree of aggregate settling. A...No aggregate settling B...Slight aggregate settling C...Significant aggregate settling

[Measurement of adhesive strength and compressive strength]

Regarding the mortar No. 1 and No. 4, Material Ordinance 28
Adhesive strength (Kg/cm ² ) and compressive strength (Kg/cm 2 ) after days
cm ² ) was measured, and the results were as shown in Table 2. Measuring method of adhesive strength: Cut the mortar of the test specimen until it reaches the concrete surface with a diamond cutter, adhere a steel disk to the mortar surface with epoxy resin, and use a Kenken tensile tester to determine the load when it is peeled off. , the adhesive strength was determined using the following formula. Adhesive strength (Kg/cm ² ) = Load when peeled (Kg) / Adhesive area of disc (cm ² ) Method for measuring compressive strength: After 28 days of aging (cured at room temperature), use an Amsler type compression tester. It was measured.

[Mortar mix]

Ordinary Portland cement 100 parts River sand (3 mm or less) 250〃 HEMC (※1) 1.0〃 Alkylaryl sulfonate (※2) 0.5〃 Sannopco SN-148P 1.0〃 Water 58〃 (※1): Hydroxyethyl methyl cellulose,
Viscosity of 2% aqueous solution at 20°C: 30,000 centipoise (*2): Mighty 100, Kao Atlas product name [Test results] Surface smoothness A Adhesive strength (Kg/cm ² ) 12.5 No cracks Compressive strength (Kg/cm 2 ) cm ² ) 400 Slump value (cm) 12.5 Notes Example without floating water 3 Pour fresh concrete into formwork (thickness 100
mm), then mortar of the following composition was poured onto this surface (thickness: 30 mm), and after 28 days, the surface smoothness, adhesive strength, and occurrence of cracks were examined, as well as the compressive strength and slump value of the mortar. [Mortar mix] Ordinary Portland cement 100 parts River sand (3 mm or less) 250〃 MC (*) 0.5〃 Methylolmelamine 0.5〃 Sannopco SN-148P 2.0〃 Sodium silicofluoride 1.0〃 Water 47〃 (*) Metrose SM-4000, Product name manufactured by Shin-Etsu Chemical [Test results] Surface smoothness A Adhesive strength (Kg/cm ² ) 12.0 No cracks Compressive strength (Kg/cm ² ) 450 Slump value (cm) 11.5 Notes Reference example without floating water Ready-mixed concrete Pour the formwork (thickness 100
mm), then mortar of the following composition was poured onto this surface (thickness: 30 mm), and after 28 days, the surface smoothness, adhesive strength, and occurrence of cracks were examined, as well as the compressive strength and slump value of the mortar. [Mortar mix] Ordinary Portland cement 100 parts River sand (3 mm or less) 250〃 HEEC (※1) 0.2〃 Lignosulfonate (※2) 0.25〃 Sannopco SN-148P 0.2〃 Sodium aluminate 0.5〃 Water 48〃 (※ 1): Modocoll E-1200F, Modochemi AB
Product name (*2): Polylith 10L, Nisso Master Builders product name [Test results] Surface smoothness B Adhesive strength (Kg/cm ² ) 12.5 No cracks Compressive strength (Kg/cm ² ) 440 Slump value (cm) 11.0 Notes Example without floating water 4 Pour fresh concrete into formwork (thickness 100
mm), then mortar of the following composition was poured onto this surface (thickness: 20 mm), and after 28 days, the surface smoothness, adhesive strength, and occurrence of cracks were examined, as well as the compressive strength and slump value of the mortar. [Mortar mix] Ordinary Portland cement 100 parts River sand (3 mm or less) 300 HPMC (*1) 0.05 Methylolmelamine 5.0 Polyethylene oxide-polypropylene oxide block copolymer (*2) 0.5 Baked alum 0.5 Water 55 ( *1): Metrose 90SH-1500, product name manufactured by Shin-Etsu Chemical Co., Ltd. (*2): Pluronic L-61, product name manufactured by Asahi Denka [Test results] Surface smoothness A Adhesive strength (Kg/cm ² ) 12.5 Occurrence of cracks None Compressive strength (Kg/cm ² ) 350 Slump value (cm) 12.0 Remarks Example without floating water 5 Pour fresh concrete into formwork (thickness 100
mm), then pour cement paste of the following composition onto this surface (thickness: 10 mm), and examine the surface smoothness, adhesive strength, and occurrence of crap after 28 days, as well as the slump value of the cement paste and the compressive strength of the cured product. [Cement paste formulation] Ordinary Portland cement 100 parts Metrose 90SH-100 5.0〃 Methylolmelamine 1.0〃 Sannopco SN-148P 0.7〃 Baked alum 1.0〃 Water 40〃 [Test results] Surface smoothness A Adhesive strength (Kg /cm ² ) 16.5 No cracks Compressive strength (Kg/cm ² ) 490 Slump value (cm) 12.5 Notes Example 6 No floating water After applying ethylene-vinyl acetate copolymer emulsion to the concrete base, Table 3 Mortars (a) to (d) having the compositions shown in the following were poured to a thickness of 10 mm, and after curing (after 28 days), surface smoothness and occurrence of pinholes were observed. In addition, the adhesive strength was examined in the same manner as above, and P tiles were placed on the surface of the 7-day-old mortar to measure the surface adhesive strength. The results were as shown in Table 3. In addition, "90SH30000" in Table 3 is the following substance. 90SH3000: Product name manufactured by Shin-Etsu Chemical Co., Ltd., hydroxypropyl methylcellulose

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is a graph showing the slump values (cm) for mortar Nos. 1 to 4 in Example 1 when the mixing ratio of water was changed. Curve...Mortar No.1 〃 …… 〃 No.2 〃 …… 〃 No.3 〃 …… 〃 No.4

Claims (1)

[Claims] 1 Cement mortar or cement paste contains at least one main component selected from 0.01 to 10 parts by weight of nonionic cellulose ether, alkylaryl sulfonate, and water-soluble melamine-formalin resin sulfonate per 100 parts by weight of cement. 0.01 to 10 parts by weight of water reducing agent and antifoaming agent
A cement-based unevenness adjusting agent containing 0.05 to 5 parts by weight.