JP2017171537A - Cement admixture sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement admixture sheet that is convenient, is easy to measure and that is also easy to finely adjust the amount of chemical admixture to be mixed.SOLUTION: Provided is a cement admixture sheet comprising a water dispersible sheet that carries the chemical admixture component.SELECTED DRAWING: None

Description

  The present invention relates to a cement admixture sheet to be admixed when producing a cement kneaded material such as a hardened cement paste, mortar or concrete.

  Admixture (addition) is performed when producing a cement kneaded material such as cement paste, mortar, or concrete. Typical examples of such admixtures include setting retarders, setting accelerators, fibers, cement dispersants such as high-performance water reducing agents and high-performance AE water reducing agents, foaming agents, and antifoaming agents. When these admixtures are added, the admixture is added after measuring the mass or volume of the admixture to be added. At this time, a scale for measuring the admixture, a measuring device such as a graduated cylinder, or a measuring instrument was necessary.

  As a technique for easily adding an admixture to a cement kneaded material without the need for weighing, a cement composition is prepared by filling a container made of a packaging material (water-dispersible material) that dissolves or disintegrates the admixture in water or an alkaline solution. A method of adding and kneading (including a kneaded product) has been proposed (for example, see Patent Document 1 or 2).

JP 2000-302493 A Japanese Patent Application Laid-Open No. 07-138057

However, depending on the type of admixture, the amount added may be increased or decreased after confirming the properties of the manufactured kneaded material such as concrete or mortar at the construction site.
When a container made of a water-dispersible material is filled with an admixture, it can be increased or decreased only by the amount unit filled in one container, and the necessary properties may not be obtained.

  Accordingly, an object of the present invention is to provide a cement admixture that is simple and does not require measurement, and that allows easy adjustment of the amount of admixture to be mixed.

  Therefore, as a result of various studies, the present inventor makes it easy to mix the admixture into the cement paste by supporting the cement admixture component on the water-dispersible sheet and making it into a sheet, which is simple and requires a lot of labor for measurement. It has been found that it becomes easy to finely adjust the amount of the admixture which is not mixed, and the present invention has been completed.

  That is, the present invention provides the following [1] to [3].

[1] A cement admixture sheet comprising a water-dispersible sheet carrying an admixture component.
[2] The cement-mixing sheet according to [1], wherein the water-dispersible sheet has a water-soluble resin as a main component, or a water-soluble resin and an insoluble fiber as main components.
[3] Admixture component is set retarder, setting accelerator, fiber, high performance water reducing agent, high performance AE water reducing agent, foaming agent, antifoaming agent, AE agent, antifreezing agent, rust preventing agent, shrinkage reducing agent, The cement admixture sheet according to [1] or [2], which is an admixture selected from a thickener, a water retention agent, a pigment, a whitening inhibitor, a quick setting agent, a quick hardening agent, and a waterproofing agent.

  According to the present invention, the present invention can provide a cement-mixing sheet that is simple and does not require measurement, and that allows easy adjustment of the amount of admixture to be mixed. In addition, according to the present invention, the adjustment of the amount of admixture added when producing a cement kneaded product does not require a measuring instrument and a measuring instrument. A method for producing a cement kneaded material with admixture components that is easy from preparation to production is obtained. After confirming the properties of the manufactured kneaded material such as concrete or mortar at the construction site, the amount of addition can be easily increased or decreased, and a cement kneaded material having a predetermined property can be easily obtained.

The cement admixture sheet of the present invention comprises a water-dispersible sheet carrying an admixture component.
In the present invention, the water dispersibility refers to a property of being dissolved or dispersed in water or an alkaline aqueous solution, or being disintegrated in water or an alkaline aqueous solution, and the water dispersible sheet refers to a sheet having water dispersibility.
As the water-dispersible sheet, a water-soluble resin or a sheet mainly composed of a water-soluble resin and insoluble fibers is preferable because of its excellent water dispersibility.

  The water-dispersible sheet of the present invention may be in the form of a sheet, and examples thereof include a film-like sheet, a nonwoven fabric-like sheet, a woven fabric-like sheet, and a paper-like sheet. Among these, a nonwoven fabric sheet is preferable from the viewpoints of transportability, water dispersibility, product stability, and ease of handling.

  The thickness of the water-dispersible sheet of the present invention is not particularly limited, but is preferably 1 μm to 10 mm from the viewpoints of transportability, processability, solubility in water, product stability, ease of handling at the construction site, and the like. 10 micrometers-5 mm are more preferable, and 20 micrometers-1 mm are still more preferable.

Examples of water-soluble resins used in the present invention include polyvinyl alcohol-based water-soluble resins, water-soluble cellulose ethers, starches, modified starches such as etherified starches and dextrins, poly (meth) acrylic acid, polyacrylamide, polyethylene oxide, polyvinyl pyrrolidone, Preferred examples include naphthalene sulfonate formalin condensate, melamine sulfonate formalin condensate, polycarboxylate and the like. When a water-soluble resin is a main component, one or two or more kinds selected from polyvinyl alcohol-based water-soluble resins and water-soluble cellulose ethers are used as water-soluble resins in terms of excellent sheet durability and water solubility. Is preferably used.
Here, the polyvinyl alcohol-based water-soluble resin (hereinafter sometimes referred to as “PVOH-based resin”) is a product obtained by saponifying polyvinyl acetate and replacing some or all of the acetate groups with hydroxyl groups (polyvinyl alcohol, hereinafter “ PVOH ”may be abbreviated as“ PVOH ”), a part or all of the acetate group of a copolymer of vinyl acetate and another monomer substituted with a hydroxyl group (hereinafter referred to as“ PVOH copolymer ”), A functional group other than an acetic acid group (hereinafter referred to as “modified PVOH”), a PVOH copolymer having a functional group other than a hydroxyl group, an acetic acid group, and a monomer-derived functional group (hereinafter referred to as “modified PVOH copolymer”). "). Here, examples of the functional group other than the hydroxyl group and the acetic acid group include a carbonyl group, a carboxyl group, an ethylene oxide group, a propylene oxide group, an acetoacetyl group, an acyl group, a sulfonic acid group, a cation group (quaternary ammonium salt), and a halogen. , Phenyl group, diacetone acrylamide group, mercapto group, silanol group and the like.

  The insoluble fiber contained in the water-dispersible sheet is not particularly limited as long as it is a fiber that is insoluble or hardly soluble in water, but polyethylene fiber, polypropylene fiber, nylon fiber, cellulose fiber (pulp fiber), polyester fiber, vinylon fiber, etc. A water-insoluble organic fiber is a preferred example.

The admixture component in the present invention is not particularly limited as long as the admixture is miscible with the cement kneaded material. For example, cement such as a setting retarder, a setting accelerator, fiber, a high-performance water reducing agent, a high-performance AE water reducing agent, and the like. Dispersants, foaming agents, antifoaming agents, AE agents, antifreeze agents, rust preventive agents, shrinkage reducing agents, thickeners, water retention agents, pigments, whitening prevention agents, quick setting agents, quick hardening agents, waterproofing agents, etc. A preferred example is given. Among these, a setting retarder, a setting accelerator, a high-performance water reducing agent, a high-performance AE water reducing agent, a thickener, a water retention agent, a foaming agent, an antifoaming agent, an AE agent, a quick setting agent, a rapid hardening agent, and the like are particularly preferable. .
The admixture component is supported on the water dispersible sheet as long as the admixture component is uniformly contained in the water dispersible sheet or a uniform admixture component-containing layer is formed on the surface of the water dispersible sheet. . The amount of the admixture component supported in the water dispersible sheet is preferably 1% by mass to 200% by mass with respect to the mass of the water dispersible sheet from the viewpoint of simplification of work and management at the construction site, and 5% by mass to 150% by mass. % Is more preferable.

  The method for producing the water-dispersible sheet carrying the admixture component is not particularly limited, but the method for producing the water-dispersible sheet after adding the admixture component to the raw material of the water-dispersible sheet and the water-dispersible sheet are produced. Examples thereof include a method of adding an admixture component later and a method of adding an admixture component when producing a water-dispersible sheet.

  The method for producing the sheet is not particularly limited, but a method of rolling a water-soluble resin or a mixture of a water-soluble resin and an insoluble fiber, an aqueous solution of a water-soluble resin, or an aqueous solution of a water-soluble resin in which insoluble fibers are dispersed are used for a plate or a belt. A method of evaporating water after spreading on, a method of forming and producing a nonwoven fabric from a water-soluble resin in which fibers or water-insoluble fibers are dispersed as a main component, water-soluble resin as a binder, A preferable example is a method of forming a sheet (for example, a papermaking method). When the water-dispersible sheet is a non-woven fabric produced by a method for forming and producing a non-woven fabric or a water-soluble paper produced by a papermaking method, the surface area of the water-soluble resin per apparent area of the sheet is large, and when it is put into water It is preferable because the water-soluble resin is easily dissolved. The method for forming and producing the nonwoven fabric can be the same method as the method for producing the nonwoven fabric with a water-insoluble resin such as polypropylene and polyester. In the case of a PVOH-based resin water-dispersible sheet, a film-like one is preferable because it is easily dissolved.

  The cement admixture sheet of the present invention is kneaded after adding a predetermined amount (predetermined area) to kneaded water, the material before kneading of the cement kneaded material, the cement kneaded material being kneaded, or the cement kneaded material after kneading. .

  The amount of the cement-mixing sheet of the present invention is added after obtaining the required area of the sheet in advance. The sheet is preferably printed or perforated, and the required amount is cut off at the mesh and mixed with the cement kneaded material, so that the amount of the admixture can be more easily adjusted.

  EXAMPLES Next, an Example is given and this invention is demonstrated in detail.

Example 1
By immersing a methanol solution of citric acid in a polyvinyl alcohol water-soluble resin film (commercially available) so that the amount of citric acid added becomes 60 g / m ^2, and then evaporating the methanol, A water-dispersible sheet (thickness 80 μm) made of PVOH resin carrying a certain citric acid was prepared.

The PVOH-based resin water-dispersible sheet 0.01 m ² prepared in 400 g of kneaded water (water) was added and then stirred to dissolve the PVOH-based resin water-dispersible sheet containing the citric acid. A total amount of this kneaded water was mixed with 1000 g of ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., the same below) using a Hobart mixer N-50 in accordance with JIS R 5201 to prepare a cement paste. . The content of citric acid contained in the cement paste at this time was 0.06 parts by mass with respect to 100 parts by mass of cement.
The completion time of the produced cement paste was measured according to JIS R 5201. The termination time was 8 hours 30 minutes.

(Example 2)
A methanol solution of calcium nitrate is soaked in water-soluble paper (commercially available) produced by a paper making method using cellulose fiber (pulp fiber) and water-soluble cellulose ether so that the added amount of calcium nitrate is 6.0 g / m ^2. Thereafter, methanol was evaporated to prepare a water-soluble paper (water-dispersible sheet) (thickness 130 μm) carrying calcium nitrate as a cement setting accelerator.

The water-soluble paper containing calcium nitrate was dispersed in water by adding 2 m ² of the prepared water-soluble paper to 400 g of kneaded water (water) and then stirring. The total amount of this kneaded water was mixed with 1000 g of ordinary Portland cement together with a Hobart mixer N-50 in accordance with JIS R 5201 for a total of 3 minutes to prepare a cement paste. The content of calcium nitrate contained in the cement paste at this time was 1.2 parts by mass with respect to 100 parts by mass of cement.
The completion time of the produced cement paste was measured according to JIS R 5201. The termination time was 3 hours and 20 minutes.

(Comparative Example 1)
400 g of kneaded water (water) was mixed with 1000 g of ordinary Portland cement in accordance with JIS R 5201 using a mixer N-50 manufactured by Hobart for a total of 3 minutes to prepare a cement paste.
The completion time of the produced cement paste was measured according to JIS R 5201. The termination time was 6 hours.

(Comparative Example 2)
By adding 0.6 g of citric acid to 400 g of kneaded water (water) and stirring, kneaded water containing citric acid was prepared. The total amount of this kneaded water was mixed with 1000 g of ordinary Portland cement together with a Hobart mixer N-50 in accordance with JIS R 5201 for a total of 3 minutes to prepare a cement paste. The content of citric acid contained in the cement paste at this time was 0.06 parts by mass with respect to 100 parts by mass of cement.
The completion time of the produced cement paste was measured according to JIS R 5201. The termination time was 8 hours 15 minutes.

(Comparative Example 3)
By adding 12 g of calcium nitrate to 400 g of kneaded water (water) and stirring, kneaded water containing calcium nitrate was prepared. The total amount of this kneaded water was mixed with 1000 g of ordinary Portland cement together with a Hobart mixer N-50 in accordance with JIS R 5201 for a total of 3 minutes to prepare a cement paste. The content of calcium nitrate contained in the cement paste at this time was 1.2 parts by mass with respect to 100 parts by mass of cement.
The completion time of the produced cement paste was measured according to JIS R 5201. The termination time was 3 hours 25 minutes.

  Table 1 shows the addition amount of the admixture contained in the water-dispersible sheets of Example 1 and Example 2, and the addition amount of the admixture added directly to the cement paste (mixed water) of Comparative Examples 1 to 3. It was. In addition, Table 1 shows the completion time of each cement paste.

(Example 3)
Polycarboxylic acid ether-based high-performance AE water reducing agent ("Master Glenium SP8SV" manufactured by BASF Japan Ltd. (trade name) (trade name) manufactured by papermaking method using cellulose fiber (pulp fiber) and water-soluble cellulose ether ), by adding the amount of the aqueous solution) of a polycarboxylic acid ether compound is dried after impregnated so as to be 120 g / m ^2, water feed carrying a high performance AE water reducing agent (water-dispersible sheet) (thickness 180 μm).

  Concrete was prepared by charging 40 L of each material into a concrete mixer (nominal capacity 60 L) at a blending ratio shown in Table 2 and kneading for a total of 120 seconds. It was 12.0 cm when the produced concrete slump was measured based on JIS A1101.

The concrete materials used are shown below.
<Materials used>
・ Cement: Early strong Portland cement (manufactured by Taiheiyo Cement)
Fine aggregate: mountain sand (produced in Shizuoka, Kakegawa City, surface dry density; 2.56 g / cm ³ , water absorption rate: 1.5%, FM; 2.73)
Coarse aggregate: Crushed stone 2005 (produced in Ibaraki Prefecture, surface dry density 2.63 g / cm ³ , water absorption 0.55%, FM 6.57)
・ Water: Tap water (Sakai City, Chiba Pref.)
・ High-performance AE water reducing agent: “Master Grenium SP8SV” manufactured by BASF Japan

(Comparative Example 4)]
“Master glenium SP8SV” was directly added to the kneaded water, and the others were prepared in the same manner as in Example 3 and measured for slump.

Example 4
PVOH system in which water-insoluble separable admixture (commercial product, water-soluble cellulose ether thickener) is dispersed in water-soluble paper (commercial product) manufactured by paper making method with cellulose fiber (pulp fiber) and water-soluble cellulose ether A water solution paper carrying water-insoluble separable admixture (water dispersibility) is obtained by uniformly applying a methanol solution of the resin so that the addition amount of the water-inseparable admixture is 135 g / m ² and then evaporating the methanol. Sheet) (thickness 190 μm) was prepared.

0.02 m ² of the prepared water-soluble paper was added to mortar that was mixed for 3 minutes in total using a mixer N-50 manufactured by Hobart in accordance with JIS R 5201 at a blending ratio of 450 g of cement, 1350 g of standard sand, and 225 g of water. Later, mortar was prepared by mixing for 2 minutes. The content of the non-separable admixture in water contained in the mortar at this time was 0.6 parts by mass with respect to 100 parts by mass of cement. The amount of suspended solids measured for the produced mortar was 12.0 mg / L based on the Japan Society of Civil Engineers standard “Underwater separable admixture quality standard for concrete (draft)”.

(Comparative Example 5)
A mixture of 450 g cement, 1350 g standard sand, and 225 g water was mixed with mortar for 3 minutes in total using a mixer N-50 manufactured by Hobart in accordance with JIS R 5201. After adding the agent, mortar was prepared by mixing for 2 minutes. The content of the non-separable admixture in water contained in the mortar at this time was 0.6 parts by mass with respect to 100 parts by mass of cement. The amount of suspended solids measured for the produced mortar was 11.5 mg / L based on the Japan Society of Civil Engineers standard “Quality standard for water inseparable admixture for concrete (draft)”.

  Table 3 shows the amount of admixture added to the water-dispersible sheet of Example 4 and the amount of admixture added directly to the mortar (kneading water) of Comparative Example 5. In addition, the amount of suspended substances in each mortar is shown in Table 3.

(Example 5)
PVOH-based resin methanol in which powdered AE agent (commercial product, aliphatic alcohol-based foaming agent) is dispersed in water-soluble paper (commercial product) produced by a papermaking method using cellulose fiber (pulp fiber) and water-soluble cellulose ether After the solution was uniformly applied so that the amount of AE agent added was 100 g / m ² , methanol was evaporated to prepare a water-soluble paper (water-dispersible sheet) (thickness 170 μm) carrying the AE agent.

Lightweight by kneading each 10L material (water-soluble paper 0.08m ² ) of the formulation shown in Table 4 at low speed using a squirrel-type hand mixer (“Toshiba 2-speed mixer 150mm BMV-150A” manufactured by Toshiba). Concrete was produced. The amount of air in the produced lightweight concrete was measured in accordance with JIS A 1128 “Testing Method Based on Pressure of Air in Fresh Concrete—Air Chamber Pressure Method” and found to be 5.5%.

(Example 6)
Powdered antifoaming agent (“ADEKA NATE B-317F” (trade name) manufactured by ADEKA Co., Ltd., nonionic surface active agent is used for water-soluble paper (commercially available) produced by a paper making method using cellulose fiber (pulp fiber) and water-soluble cellulose ether. Water solution paper carrying an antifoaming agent (water dispersion) by applying a methanol solution of PVOH-based resin in which the agent is dispersed uniformly so that the added amount of the antifoaming agent is 100 g / m ² and then evaporating the methanol. Sheet) (thickness 170 μm).

Light weight by kneading 10L of each material (water-soluble paper 0.008m ² ) of the formulation shown in Table 4 at low speed using a squirrel-type hand mixer (Toshiba “Toshiba 2-speed mixer 150mm BMV-150A”). Concrete was produced. The amount of air in the produced lightweight concrete was measured in accordance with JIS A 1128 “Testing Method for Fresh Concrete with Air Pressure—Air Chamber Pressure Method” and found to be 2.0%.

The concrete materials used are shown below.
<Materials used>
・ Cement: Ordinary Portland cement (manufactured by Taiheiyo Cement)
Inorganic filler powder: Limestone fine powder (Blaine specific surface area; 4210 cm ² / g, Iwate Prefecture)
Fine aggregate: Artificial lightweight aggregate “Pacific Asanolite” (trade name) (manufactured by Kansai Pacific Mining Co., Ltd., surface dry density; 2.06 g / cm ³ , water absorption rate: 18.0%, FM; 2 .99)
Coarse aggregate: Artificial lightweight aggregate “Pacific Asanolite” (trade name) (Kansai Pacific Mining Co., Ltd., surface dry density 1.61 g / cm ³ , water absorption 29.0%, FM; 5.98 , Maximum dimension: 10 mm)
・ Cement dispersant: Naphthalenesulfonic acid-based high-performance water reducing agent “Mighty 100” (trade name) (manufactured by Kao Corporation)
-Thickener: Water-soluble cellulose ether "Metrozu 90SH-30000" (trade name) (manufactured by Shin-Etsu Chemical Co., Ltd., hydroxypropylmethylcellulose)
・ Water: Tap water (Sakai City, Chiba Pref.)

(Comparative Example 6)
The powdered AE agent used in Example 5 was directly added to the kneaded water, and the others were made in the same manner as in Example 5 and the amount of air measured was 5.4%.

(Comparative Example 7)
The powder defoaming agent used in Example 6 was directly added to the kneaded water, and the others were produced in the same manner as in Example 6 and the amount of air measured was 1.9%.

  Table 4 shows the addition amount of the admixture contained in the water-dispersible sheets of Example 5 and Example 6, and the addition amount of the admixture added directly to the concrete (mixed water) of Comparative Example 6 and Comparative Example 7. . In addition, the air volume of each concrete is shown in Table 4.

(Example 7)
An aqueous solution of a PVOH resin in which a foaming agent “aluminum powder” (manufactured by Toyo Aluminum Co., Ltd.) is dispersed is poured into a vat and dried to obtain a PVOH resin film having a foaming agent addition amount of 5 g / m ² (thickness 50 μm). ) Was produced.

450 g of cement, 1350 g of fine aggregate, thickener (“STARVIS SE25F” (trade name) manufactured by BASF Japan, modified starch ether) 2.0 g, antifoaming agent “Adecanate B-317F” (trade name) manufactured by ASEDA , Nonionic surfactant) The PVOH-based resin film 0 prepared in a mortar that was mixed for 3 minutes in total using a mixer N-50 manufactured by Hobart in accordance with JIS R 5201 at a mixing ratio of 2.0 g and water 225 g. After adding 004 m ² , a mortar was prepared by mixing for 2 minutes. Content of the foaming agent contained in the mortar at this time was 0.0044 parts by mass with respect to 100 parts by mass of cement.
The initial expansion coefficient of the material a day was measured according to JSCE-F 542-2010 “Testing method for bleeding rate and expansion coefficient of filling mortar” of the produced mortar and found to be 0.20%.

(Comparative Example 8)
450 g of cement, 1350 g of fine aggregate, thickener (“STARVIS SE25F” (trade name) manufactured by BASF Japan, modified starch ether) 2.0 g, antifoaming agent “Adecanate B-317F” (trade name) manufactured by ASEDA , Nonionic surfactant) Foam used in Example 7 in a mortar mixed for 3 minutes in total using a mixer N-50 manufactured by Hobart in accordance with JIS R 5201 at a mixing ratio of 2.0 g and 225 g of water. After adding the agent (aluminum powder), mortar was prepared by mixing for 2 minutes. Content of the foaming agent contained in the mortar at this time was 0.0044 parts by mass with respect to 100 parts by mass of cement.
The initial expansion coefficient of the material a day was measured according to JSCE-F 542-2010 “Testing method for bleeding rate and expansion coefficient of filling mortar” and found to be 0.23%.

  Table 5 shows the amount of admixture contained in the water-dispersible sheet of Example 7 and the amount of admixture added directly to the mortar (kneaded water) of Comparative Example 8. In addition, Table 5 shows the initial expansion rate of each mortar at the age of 1 day.

Claims (3)

  A cement admixture sheet comprising a water dispersible sheet carrying an admixture component.   The cement-mixing sheet according to claim 1, wherein the water-dispersible sheet is mainly composed of a water-soluble resin, or is composed mainly of a water-soluble resin and insoluble fibers.   Admixture component is set retarder, set accelerator, fiber, high performance water reducing agent, high performance AE water reducing agent, foaming agent, antifoaming agent, AE agent, antifreeze agent, rust preventive, shrinkage reducing agent, thickener. The cement admixture sheet according to claim 1 or 2, which is an admixture selected from a water retention agent, a pigment, a whitening prevention agent, a quick setting agent, a quick hardening agent, and a waterproofing agent.