JPH10139516A - One-powder type fiber reinforced mortar composition for coating and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a moltar composition capable of easily formulating only by adding water at a working job site, hardly forming an aggregated matter and capable of manifesting an excellent strength by blending a cement, a reemulsifiable powdery resin, a fluidizing agent, an anti-foaming agent, sand and fiber. SOLUTION: In the moltar composition, a cement, a reemulsifiable powdery resin, a fluidizing agent, an anti-foaming agent, sand and fiber are incorporated. In its production, after forming a mixture by mixing cement, the reemulsifiable powdery resin, the fluidizing agent, the anti-foaming agent and the fiber, the sand is added and mixed to the mixture. A blending proportion is, for example, 100 pts.wt. cement, 1-40 pts.wt. reemulsifiable powdery resin, 0.01-3 pts.wt. fluidizing agent, 0.01-1 pts.wt. anti-foaming agent, 100-200 pts.wt. sand and 0.1-2 pts.wt. fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-powder type mortar composition for use as a coating material on a civil engineering site for reinforcing and repairing a structure, and a method for producing the same.

[0002]

2. Description of the Related Art Heretofore, in this type of one-powder type mortar for coating, a method of preparing a material to be used on site has been adopted. In this on-site blending, an aqueous emulsion is added to other components as a resin which is one component of the mortar composition, but there is a problem that the blending is troublesome and measurement errors easily occur. When cement is added to the aqueous emulsion, the dispersion of the cement becomes poor, and there is a disadvantage that cement aggregates are easily generated. Also, after the water and cement are kneaded in advance, if the aqueous emulsion is added, the dispersion of the aqueous emulsion becomes poor due to the metal ions of the cement, and the agglomerates of the aqueous emulsion tend to be formed. Emulsion aggregates need to be removed.

[0003]

In order to solve such a problem, it has been proposed to use a re-emulsifiable powder resin, but there is a problem that the strength of the applied and cured mortar is reduced. . An object of the present invention is to provide a one-powder type fiber-reinforced mortar composition for application that can be easily prepared simply by adding water at the site of use, and that can exhibit excellent strength without generating undesirable aggregates. To provide. Another object of the present invention is to provide a method for producing a one-powder type fiber reinforced mortar composition for coating, which can uniformly disperse fibers in the mortar composition.

[0004]

The invention according to claim 1 is
A one-powder type fiber-reinforced mortar composition for application, comprising cement, a re-emulsifiable powder resin, a fluidizing agent, an antifoaming agent, sand and fibers. Inclusion of fibers enhances strength expression.

[0005] The invention according to claim 2 is a coating method in which cement, a re-emulsifiable powder resin, a fluidizing agent, an antifoaming agent and fibers are mixed to form a mixture, and sand is added to the mixture and mixed. This is a method for producing a one-powder type fiber-reinforced mortar composition for use.
According to this method, the fibers can be uniformly dispersed in the mortar composition, thereby increasing the strength development.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The mortar composition according to the present invention comprises 1 to 40 parts by weight of a re-emulsifiable powder resin and 0.01 to 3 parts by weight of a fluidizer per 100 parts by weight of cement. And 0.01 to 1 part by weight of an antifoaming agent, 100 to 200 parts by weight of sand, and 0.1 to 2 parts by weight of fiber. Claim 1
The preferred content of the re-emulsifiable powder resin is 5 to 2
5 parts by weight, and the preferred content of the fluidizing agent is 0.1 to
1.5 parts by weight, and the preferable content of the antifoaming agent is 0.0
5 to 0.5 parts by weight, and the preferred content of sand is 100
To 150 parts by weight, and the preferable content of the fiber is 0.1
１1 part by weight. In the first aspect, 3 to 9 parts by weight of an expanding material may be further included.

If the re-emulsifiable powder resin is less than the above lower limit,
It is inferior in durability and elasticity development, and if it exceeds the above upper limit, the effect is small and the economy is poor. When the fluidizing agent is less than the above lower limit, sufficient fluidity cannot be obtained, and when the fluidizing agent exceeds the above upper limit, problems such as setting delay are caused. If the defoaming agent is less than the above lower limit, a sufficient defoaming effect will not be exhibited, and if the defoaming agent exceeds the upper limit, the effect will be small and the economic efficiency will deteriorate. If the amount of sand is less than the above lower limit, a sufficient effect of reducing the binder is not obtained. If the amount of sand exceeds the above upper limit, workability is poor and problems such as an increase in the amount of water occur. If the fiber is less than the above lower limit, sufficient strength cannot be obtained, and if the fiber exceeds the above upper limit, a problem that a fiber mass is formed in the mortar composition occurs.

[0008] Each material constituting the mortar composition of the present invention will be described in detail. The cement of the present invention includes (A) Portland cements such as ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, moderate heat Portland cement, sulfate-resistant Portland cement, belite cement, white Portland cement, and the like. ) Blended cement such as blast furnace cement, fly ash cement, silica cement, silica fume cement, etc., (c) Special cement such as calcium aluminate-based special cement, alumina cement, ultra-rapid hardening cement, etc.
Soil stabilizing cement and the like. The above cements (A) to (D) may be used alone or in combination of two or more.

[0009] The re-emulsifiable powder resin of the present invention is a powder obtained by drying a synthetic resin emulsion obtained by emulsion polymerization in the form of particles, and in particular, a powder which is re-emulsified when added to water and stirred. Usually, it is obtained by spray drying a vinyl resin emulsion. Specific examples of the re-emulsifiable powder resin include polymers and copolymers of vinyl acetate, acrylate, methacrylate, and styrene. The fluidizing agent of the present invention, β-naphthalene sulfonic acid condensate salt, creosote oil sulphonic acid condensate salt, melamine resin sulfonic acid condensate salt, gluconate, lignin sulfonate, polyoxyethylene nonyl phenyl ether, And polycarboxylates.

The antifoaming agent of the present invention includes ethers, fatty acid esters, fatty acid amides, fatty acid metal soaps, higher alcohols, highly polymerized glycols, organic phosphates, silicones and the like. The sand of the present invention includes river sand, mountain sand, sea sand,
Examples include silica sand, artificial fine aggregate, crushed sand, natural silica sand, and the like. The fibers of the present invention include vinylon fibers, carbon fibers, aramid fibers, polyethylene fibers, polypropylene fibers, glass fibers, steel fibers and the like. Examples of the expanding material of the present invention include bauxite, lime, calcium-sulfoaluminate-based materials obtained by calcining gypsum, and lime-based materials obtained from anhydrous gypsum and limestone powder.

[0011]

Next, examples of the present invention will be described together with comparative examples. <Example 1> Re-emulsifiable powder resin (acrylate ester) 2 with respect to 100 parts by weight of ordinary Portland cement
0 parts by weight, a fluidizing material (highly condensed naphthalenesulfonic acid) 0.3 parts by weight, and an antifoaming agent (higher alcohol-based)
4 parts by weight, 0.3 parts by weight of fiber (vinylon type 6 mm) and swelling agent (calcium sulfoaluminate type) 6.3
A part by weight was collected and put into a V-type mixer to mix uniformly.
Next, 150 parts by weight of silica sand was collected as sand, and the mixture was uniformly mixed in the V-type mixer to prepare a mortar composition.

<Comparative Example 1> A mortar composition was prepared by repeating the same procedure as in Example 1 except that no fiber and no expanding material were used. Table 1 shows the compounding contents of Example 1 and Comparative Example 1.

[0013]

[Table 1]

<Physical Properties of Mortar and Specimen Prepared by Adding Water to Mortar Composition> (a) Fluidity (Flow) Test The fluidity was measured according to JIS R 5201 "Physical Testing Method for Cement" 9.7. The test was performed according to the test. That is, as shown in Table 2, water was added to the mortar compositions of Example 1 and Comparative Example 1 at a water material ratio of 18 (the ratio of water to mortar composition 1 was 18), mixed with a mixer, and immediately subjected to a flow test. To obtain a value, and the fluidity was evaluated. Table 2 shows the results.

(B) Drying Shrinkage Test A drying shrinkage test was carried out in accordance with JIS A 1129 “Testing method of mortar / concrete length change rate”. Water was added to the mortar compositions of Example 1 and Comparative Example 1 at a water material ratio of 18 as shown in Table 2, mixed with a mixer, and mixed with 4 × 4 ×
It was packed in a 16 cm mold, stored in a room at 20 ° C. and 80% RH for 24 hours, and then demolded. After measuring the reference length, the specimen was stored in a room at 20 ° C. and 60% RH, and the length change rate after 13 weeks was measured. Table 2 shows the results.

(C) Strength test The flexural strength and the compressive strength are determined by the physical test method of cement (JI
(SR5201-192) ". That is, from the mortar immediately after the mortar composition of Example 1 and Comparative Example 1 was prepared by adding water, a test piece of a prism having a cross section of 40 mm square and a length of 160 mm was prepared. Tensile strength is JI
The test was performed in accordance with SA 1113 “Test method for tensile strength of concrete”. The specimen was a cylindrical specimen having a diameter of 5 cm × 10 cm. When the material age of the test specimens was 7 days and 28 days, three specimens were subjected to the tests of compression strength, bending strength, and tensile strength. Table 2 shows the results.

(D) Static modulus of elasticity The static modulus of elasticity is referred to as “Test method for static modulus of concrete
SCE-G502) ". That is, a mortar prepared from the mortar compositions of Example 1 and Comparative Example 1 was molded into a cylindrical test specimen having a diameter of 5 cm and a height of 10 cm,
A strain gauge is mounted on two lines parallel and symmetrical to the axis of the specimen and centered on one-half the height of the specimen, and the respective static elastic moduli at one-third of the maximum stress are determined. I asked. Table 2 shows the results.

[0018]

[Table 2]

The following was found from Table 2. Compared with the mortar prepared from the composition of Comparative Example 1, the mortar prepared from the composition of Example 1 had a drying shrinkage strain reduced by half. Further, as compared with the specimen of Comparative Example 1, the specimen of Example 1 had higher compressive strength, bending strength, and tensile strength. Further, with respect to the static elastic modulus,
The specimen of No. was superior to the specimen of Comparative Example 1.

<Comparative Example 2> Sand is put in a V-type mixer at the same time as ordinary Portland cement together with other components such as a re-emulsifiable powder resin, a fluidizing agent, a defoamer, a fiber and an expanding agent. A mortar composition was prepared by repeating the same method as in Example 1 except that the mortar was mixed. Water was added to this composition at a water material ratio of 18 as shown in Table 3 and mixed with a mixer to prepare a mortar. Table 3 shows the physical properties of the mortar and the test specimen formed therefrom. Table 3 also shows the physical properties of Example 1 for comparison.

[0021]

[Table 3]

As is clear from Table 3, the specimen of Comparative Example 2 had lower compressive strength, bending strength and tensile strength than the specimen of Example 1.

[0023]

As described above, according to the present invention, water is added at the point of use by further containing fibers in addition to cement, the re-emulsifiable powder resin, the superplasticizer, the defoamer and the sand. It can be easily prepared by simply performing the process, and can exhibit excellent strength without generating undesirable aggregates. Also, after mixing the cement, the re-emulsifiable powder resin, the fluidizing agent, the defoaming agent, and the fiber to form a mixture, sand was added to the mixture and mixed. It can be dispersed in an object.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 24:02 16:06 22:14) 103: 30 103: 50 103: 60 111: 72 (72) Inventor Konosuke Takahara Saitama 1-297 Kitabukuro-cho, Omiya City Mitsubishi Materials Corporation Cement Research Institute

Claims (2)

[Claims] 1. A one-powder type fiber-reinforced mortar composition for application comprising cement, a re-emulsifiable powder resin, a fluidizing agent, an antifoaming agent, sand and fibers. 2. A one-powder type fiber reinforcement for application wherein a mixture is formed by mixing cement, a re-emulsifiable powder resin, a fluidizing agent, an antifoaming agent, and a fiber, and sand is added to the mixture to be mixed. A method for producing a mortar composition.