JP2014218415A - Quick-hardening polymer cement mortar composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quick-hardening polymer cement mortar composition which can secure a sufficient pot life even after a product is stored for a long term.SOLUTION: Provided are: (1) a quick-hardening polymer cement mortar composition comprising cement, a polymer, fine aggregate, a super quick-hardening clinker, gypsum, a coagulation regulator, where the super quick-hardening clinker is a CaO-AlO-based super quick-hardening clinker including a carbonic acid component; (2) the quick-hardening polymer cement mortar composition according to (1) where the super quick-hardening clinker contains 29.9 to 65% of CaO, 29.9 to 70% of AlO, and 0.1 to 5% of a carbonic acid component as CO; (3) the quick-hardening polymer cement mortar composition according to (1) or (2) containing a shrinkage-reducing agent; and (4) the quick-hardening polymer cement mortar composition according to any of (1) to (3) containing fibers.

Description

  The present invention mainly relates to a hardened polymer cement mortar composition used in the field of civil engineering and construction.

Concrete structures may deteriorate due to salt damage, neutralization, freezing and thawing, chemical corrosion, and the like, and the surface may be cracked or floated. As countermeasures, a construction is performed in which a deteriorated portion is confirmed by a hammering inspection or the like, removed by an electric pick, an air pick, a water jet, or the like, and newly repaired with a repair member. In small-scale repair work with a small repair cross section, cross-section repair is often performed by kneading polymer cement mortar and applying a trowel (see Patent Documents 1 and 2).

Furthermore, a rapid-hardening polymer cement composition for the purpose of reducing drying shrinkage due to cement hydrate and improving initial strength is also known (see Patent Documents 3 and 4).

By using polymer cement mortar, durability and cure shrinkage can be greatly improved as compared with mortar not containing polymer, but water retention at the stage where it does not cure cannot be improved, and cracks may occur in the initial stage. Cellulose ether can be added for the purpose of improving water retention, but this has a problem that the setting of mortar is delayed.
For ordinary polymer cement mortar with no rapid hardening, the thickness of one application is 50mm or less, and when the application thickness is more than that, it is necessary to apply after the condensation of the first layer mortar has progressed to some extent. In general, it is necessary to carry out after 1 to 2 hours and 4 to 5 hours in the winter, and it takes a long time to finally finish.

In view of this, a repair mortar in which setting is not delayed even in a low temperature environment by using an expansion material, a drying shrinkage reducing agent and a setting accelerator together has been proposed (see Patent Document 5).

JP 2001-322858 A JP 2003-89565 A Japanese Patent Laid-Open No. 3-177346 JP-A-4-321540 JP 2005-82434 A

The rapid hardening polymer cement mortar needs to have a certain pot life in order to be placed after being kneaded. Usually, oxycarboxylic acid, its salt, or alkali metal is used as a setting modifier. The combined use of carbonates, sugars and the like can be mentioned.
However, when these setting modifiers are mixed with a rapid hardening material or a rapid hardening cement in advance, there is a problem that the performance deteriorates with storage and the pot life is likely to change.

Therefore, as a result of various efforts to solve the above-mentioned problems, the present inventor has found that a quick-hardening polymer cement mortar excellent in storage stability can be prepared with a quick-hardening material made of a specific ultrafast hardening clinker. The present invention has been completed.
The present invention provides a rapid-curing polymer cement mortar composition that can ensure a sufficient pot life even when the product is stored for a long period of time.

The present invention is (1) a CaO—Al ₂ O ₃ based ultrafast hard clinker comprising a cement and a polymer, a fine aggregate, a super fast hard clinker, gypsum and a setting regulator, and the super fast hard clinker contains a carbonic acid component. A certain quick-hardening polymer cement mortar composition, (2) Super fast hardening clinker, CaO 29.9-65%, Al ₂ O ₃ 29.9-70%, carbonic acid component 0.1-5 in terms of CO ₂ (1) The rapid hardening polymer cement mortar composition comprising (1), (3) The rapid hardening polymer cement mortar composition comprising (1) or (2) a shrinkage reducing agent, and (4) fibers. (1) to the rapid hardening polymer cement mortar composition according to any one of (3).

The rapid hardening polymer cement mortar composition of the present invention has an effect that a sufficient pot life can be secured even when stored for a long period of time.

Hereinafter, the present invention will be described in detail.
The parts and% used in the present invention are based on mass unless otherwise specified.

The cement used in the present invention is not particularly limited, and normal, early strength, very early strength, low heat, and moderate heat Portland cement, and these portland cements include blast furnace slag, fly ash, or silica. Examples include various mixed cements, eco-cement, white cement, super-hard cement, filler cement mixed with fine limestone powder, and the like.

The polymer used in the present invention is, for example, a polymer for cement admixture specified in JIS A 6203, such as a polymer dispersion in which fine particles of polymer are dispersed in water, rubber latex, and resin emulsion. This refers to re-emulsifying powder resin obtained by drying a stabilizer added, etc., improving durability such as neutralization, salt damage, frost damage, etc., mortar adhesion strength, bending strength, tensile strength It is used for the purpose of improving the strength characteristics.
For example, rubber latex such as acrylonitrile / butadiene rubber, styrene / butadiene rubber, chloroprene rubber, and natural rubber, ethylene / vinyl acetate copolymer, polyacrylic acid ester, vinyl acetate vinyl versatate copolymer, and styrene / acrylic. Examples include acid ester copolymers, acrylic ester copolymers typified by acrylonitrile / acrylic acid esters, epoxy resins, liquid polymers typified by unsaturated polyester resins, and the like. Mixtures can be used.

The amount of the polymer used in the present invention is preferably 1 to 20 parts, more preferably 3 to 10 parts in terms of solid content with respect to 100 parts of a binder composed of cement, super-hard hard clinker and gypsum. If it is less than 1 part, the durability improvement effect is small, and if it exceeds 20 parts, strength development may be affected.

The super-hard hard clinker of the present invention is synthesized by using calcium aluminate as a base material and reacting with carbon dioxide gas. The clinker is usually a lump having a size of about 5 to 30 mm and is used after being pulverized. The clinker referred to in the present invention is a general term for lump, powder and the like.
The calcium aluminate used in substrate, a raw material containing calcia, by mixing a raw material containing alumina, calcined and in the kiln, obtained by heat treatment such as melting in an electric furnace, CaO and Al ₂ It is a general term for substances having O ₃ as a main component and having hydration activity, and a part of CaO and / or Al ₂ O ₃ is an alkali metal oxide, an alkaline earth metal oxide, silicon oxide, titanium oxide, To compounds having iron oxide, alkali metal halide, alkaline earth metal halide, alkali metal sulfate, alkaline earth metal sulfate, or the like, or having CaO and Al ₂ O ₃ as main components, These are substances dissolved in a small amount. The mineral form may be either crystalline or amorphous.
Incidentally, within a range not impairing the effects of the present invention _CaO, may contain a _{Al 2 O} 3, CO ₂ and other components other than. Other components include SiO ₂ , Fe ₂ O ₃ , MgO, TiO ₂ , ZrO ₂ , MnO, P ₂ O ₅ , Na ₂ O, K ₂ O, Li ₂ O, sulfur, fluorine, chlorine and moisture. An ignition loss component etc. are mentioned. The content of other components is usually in the range of 0 to 10%.
The chemical components of the ultrafast hard clinker of the present invention are preferably CaO 29.9 to 65%, Al ₂ O ₃ 29.9 to 70%, and carbonic acid component 0.1 to 5% in terms of CO _2. . Without this component range, it may be difficult to ensure sufficient pot life when stored. .

When using an ultra-fast curing clinker in a rapid-curing polymer cement mortar composition, it is preferable to adjust the brane specific surface area to 4000 to 9000 cm ² / g. When the calcium aluminate has a fineness of 4000 cm ² / g or less in terms of Blaine specific surface area, sufficient ultra-fast hardness may not be obtained, or strength development at low temperatures may not be sufficient. Further, even if it exceeds 9000 cm ² / g, further enhancement of the effect cannot be expected.

The treatment method of calcium aluminate, which is a base material for the ultra-fast hard clinker, with carbon dioxide gas is not particularly limited, and can be synthesized by bringing calcium aluminate into contact with carbon dioxide gas. From the viewpoint of storage stability, it is preferable to contact with carbon dioxide. Moreover, it is preferable to perform the carbonation of calcium aluminate after grinding the clinker.
The carbonation treatment vessel used in the present invention is not particularly limited, as long as the clinker and carbon dioxide gas can be brought into contact with each other and allowed to react, and an electric furnace, a fluidized bed heating furnace, or a super speed may be used. A mill for grinding hard clinker may be used.

The carbonic acid component (CO ₂ ) contained in the ultrafast hard clinker of the present invention can be measured by an inorganic carbon analysis method. Hydrochloric acid is applied to the ultra-fast hard clinker, and the generated CO ₂ is absorbed into the absorption liquid, and can be quantified by a titration method. As a specific apparatus, a “Coolometer” manufactured by Nippon Anse Co., Ltd. can be used.

Any gypsum can be used as the gypsum used in the present invention. Among these, anhydrous gypsum is preferable in terms of strength development, and type II anhydrous gypsum is preferable.
The particle size of the gypsum, preferably 4000 cm ² / g or more in Blaine specific surface area, 5000~7000cm ² / g is more preferable. If it is less than 4000 cm < ² > / g, initial strength development may fall.
The amount of gypsum used is preferably from 25 to 200 parts, more preferably from 50 to 150 parts, and most preferably from 75 to 125 parts, based on 100 parts of the ultrafast curing clinker. Outside these ranges, strength development may be reduced.

  The amount of the rapid hardening component composed of the super fast hardening clinker and gypsum is preferably 10 to 35 parts, more preferably 15 to 25 parts, out of a total of 100 parts of cement, super fast hardening clinker and gypsum. If it is less than 10 parts, the initial strength development may be small, and if it exceeds 35 parts, there will be no significant effect and the long-term strength may be reduced.

The setting modifier of the present invention makes it possible to ensure the working time during construction, and is usually used in powder form. The types of setting regulators include oxycarboxylic acids such as citric acid, tartaric acid, gluconic acid, malic acid and their metal salts, phosphates such as tripolyphosphate and sodium monophosphate, sucrose, fructose, etc. Examples thereof include saccharides, borates such as sodium borate, silicofluorides such as magnesium silicofluoride, and one or more of these can be used in combination. Moreover, it is also possible to use what combined carbonate, a sulfate, nitrate, nitrite etc. with these setting regulators.
The amount of use of the setting modifier varies depending on the use, the construction work time, the composition of the setting agent, etc., and it is difficult to determine uniquely. In the present invention, the use amount is adjusted so that the rapid hardening polymer cement mortar composition is cured in accordance with the working time of 30 to 90 minutes.
The amount of use of the setting modifier of the present invention is 0. 0 with respect to 100 parts of a binder composed of cement and a rapid hardening component. 05 to 2 parts are preferable, and 0.1 to 1 part is more preferable. If it is less than 0.05 part, it is difficult to delay the setting, and if it exceeds 2 parts, strength development may be inhibited.

The shrinkage reducing agent used in the present invention is one that prevents the diffusion of unreacted water and suppresses drying shrinkage of cement hydrate. Specifically, alcohol-based, lower alcohol alkylene oxide derivative-based, glycol-based Organic compounds having a surfactant activity such as glycol ether / amino alcohol derivative and polyether can be used.
The amount of the shrinkage reducing agent used is preferably 1 to 8 parts with respect to 100 parts of the binder composed of cement and a rapid hardening component. If the amount is less than 1 part, the shrinkage reduction effect may not be sufficient. If the amount exceeds 8 parts, not only the cost will be increased, but also the fluidity at the time of freshness may be reduced, or the setting delay or strength may be reduced.

The fibers used in the present invention improve crack resistance and bending strength.
Examples of the fibers include polymer fibers such as vinylon fibers, propylene fibers, and nylon fibers, and inorganic fibers represented by steel fibers, glass fibers, and carbon fibers, and are not particularly limited.
The amount of fibers used is preferably 0.05 to 0.7 parts, more preferably 0.08 to 0.5 parts, with respect to 100 parts of the quick-hardening polymer cement mortar composition. If it is less than 0.05 part, the effect of improving the bending strength may not be exhibited, and if it exceeds 0.7 part, the fluidity of the mortar may be adversely affected. The length of the fiber is preferably 15 mm or less in view of the beauty of the iron finish surface.

In the present invention, a water reducing agent can be used. The type is not particularly limited, and is a general term for those having a dispersing action and air entraining action on cement, improving fluidity and enhancing strength. Specifically, naphthalene sulfonic acid water reducing agent, melamine sulfonic acid type Water-reducing agents, lignin sulfonic acid-based water reducing agents, and polycarboxylic acid-based water reducing agents can be used, and the use form of the water reducing agent can be either liquid or powder, but when used as a premix product Powder is preferred.
The amount of water reducing agent used is not particularly limited. Although there is a difference in the water reduction rate depending on the type of water reducing agent and the appropriate amount is different, usually 0.05 to 1.0 part in terms of solid content is preferable with respect to 100 parts of the binder composed of cement and a rapid hardening component. If it is less than 0.1 part, the fluidity may not be sufficient, and if it exceeds 1.0 part, sagging may occur during plastering.

In the present invention, an antifoaming agent can be further used. An antifoaming agent can be used for the purpose of adjusting moderate air entrainment. The types of antifoaming agents include: polyether oxide defoamers such as alkylene oxide adducts of higher fatty acids, glycol oxide oxide adducts, silicone defoamers such as dimethyl silicone, and trialkyl phosphate deodorants such as tributyl phosphate. There are foaming agents.
The amount of the antifoaming agent used is preferably 0.001 to 0.5 part, more preferably 0.003 to 0.1 part, with respect to 100 parts of the binder composed of cement and a rapid hardening component. If it is less than 0.001 part, the defoaming effect is small, and even if it exceeds 0.5 part, the defoaming effect reaches its peak and may be uneconomical.

Examples of the fine aggregate used in the present invention include commonly used river sand, sea sand, crushed sand, silica sand, lightweight aggregate, etc., and one or more of them can be used in combination. These dry sands are preferred when used as a premix product.
The maximum particle size of the fine aggregate is preferably 2 mm or less. If it is more than that, workability at the time of iron finishing may be impaired, and the finished surface may feel rough.
The amount of fine aggregate used is preferably 50 to 250 parts with respect to 100 parts of the binder composed of cement and a rapid hardening component. If the amount exceeds 250 parts, insufficient strength occurs or workability is impaired. There is.

The amount of kneading water used in the present invention is not particularly limited, but is usually preferably 25 to 50% and more preferably 30 to 45% in terms of water / binder ratio. Outside this range, kneading may be difficult, and material separation or strength reduction may occur.

Further, as an additive (agent), one of a thickener, a rust inhibitor, a defrost agent, a foaming agent, a clay mineral such as bentonite, an ion exchanger such as zeolite, a fine siliceous powder, calcium carbonate and calcium hydroxide. Species or two or more species can be used as long as the object of the present invention is not substantially inhibited.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

"Experiment 1"
Using various types of ultrafast hard clinker shown in Table 1, with respect to 100 parts of a binder consisting of 80 parts of cement, 10 parts of super fast hard clinker and 10 parts of anhydrous gypsum, 0.3 part of a setting modifier, 200 parts of aggregate Then, 7 parts of the polymer was uniformly mixed in a V-type blender to prepare a quick hardening polymer cement mortar composition. Thereafter, in a room at 20 ° C., 42 parts of water was added to 100 parts of the binder, and the mixture was kneaded with a mortar mixer to obtain mortar, and the fluidity, pot life, and compressive strength were measured. The results are shown in Table 1.
Furthermore, the same experiment was conducted on the quick-hardening polymer cement mortar composition subjected to the accelerated storage test.

(Materials used)
Cement: Ordinary Portland cement, commercially available super fast hard clinker A: CaO 63.6%, Al ₂ O ₃ 34.4%, CO ₂ 0%, others 2.0%. After firing at 1450 ° C., the powder was pulverized to a specific surface area of 5000 cm ² / g.
Super fast hard clinker B: Super fast hard clinker A (pulverized product) treated with carbon dioxide gas at 600 ° C. atmosphere. _{CaO62.7%, Al 2 O 3 33.8} %, CO 2 1.5%, other 2.0%. Blaine specific surface area 5000 cm ² / g.
Super fast hard clinker C: CaO 49.5%, Al ₂ O ₃ 47.5%, CO ₂ 0%, other 3.0%, calcined after firing at 1450 ° C. to a Blaine specific surface area of 5000 cm ² / g.
Super fast hard clinker D: Super fast hard clinker C (pulverized product) treated with carbon dioxide gas at 600 ° C. atmosphere. CaO 49.0%, Al ₂ O ₃ 47.2%, CO ₂ 0.8%, Others 3.0%, Blaine specific surface area 5000 cm ² / g.
Super fast hard clinker E: CaO 36.0%, Al ₂ O ₃ 60.1%, CO ₂ 0%, other 3.9%, baked at 1450 ° C. and pulverized to a specific surface area of 5000 cm ² / g.
Super fast hard clinker F: Super fast hard clinker E (pulverized product) treated with carbon dioxide gas at 600 ° C. atmosphere. CaO 36.3%, Al ₂ O ₃ 60.5%, CO ₂ 0.2%, others 3.0%. Blaine specific surface area 5000 cm ² / g.
Super-hard clinker G: Super-hard clinker C (ground product) treated with carbon dioxide gas at 200 ° C. CaO 49.4%, Al ₂ O ₃ 47.4%, CO ₂ 0.2%, Others 3.0%, Blaine specific surface area 5000 cm ² / g.
Super-hard clinker H: Super-hard clinker C (pulverized product) treated with carbon dioxide gas at 400 ° C. atmosphere. CaO 49.2%, Al ₂ O ₃ 47.2%, CO ₂ 0.6%, Others 3.0%, Blaine specific surface area 5000 cm ² / g.
Super-hard clinker I: Super-hard clinker C (ground product) treated with carbon dioxide gas at 800 ° C. atmosphere. CaO 49.0%, Al ₂ O ₃ 47.0%, CO ₂ 1.0%, Others 3.0%, Blaine specific surface area 5000 cm ² / g.
Setting controller: Reagent grade 1 citric acid anhydrous gypsum: type II anhydrous gypsum, Blaine specific surface area 5000 cm ² / g
Fine aggregate: limestone crushed sand, maximum particle size 1.2mm
Polymer: Acrylic-vinyl acetate-vinyl versatate copolymer, commercial product

(Measuring method)
Flowability: Measured according to the flow test of JIS R5201.
Pot life: The pot life was the time when the temperature rose by 1 ° C. from the kneading temperature.
Compressive strength: Compressive strength for 4 hours was measured according to JIS A1171.
Accelerated storage test: 25 kg of quick-hardening polymer cement mortar composition is packed in a packing material in which a 20 μm-thick high-density polyethylene sheet is attached to the interior of triple kraft paper, sealed, and 1 in a 35 ° C., 90% RH room Remained for months.

According to Table 1, it can be seen that by using the quick-hardening polymer cement mortar composition of the present invention, good fluidity and working time are ensured after storage as well as immediately after blending.

"Experimental example 2"
Using a super-hard clinker D, the length change rate and the adhesion strength were measured in the same manner as in Experimental Example 1 except that the amount of the shrinkage reducing agent shown in Table 2 was blended with 100 parts of the binder. The results are shown in Table 2.

(Materials used)
Shrinkage reducing agent: polyoxyalkylene derivative, commercially available product

(Test method)
Length change rate: The length change rate up to 28 days of material age was measured according to the test method of JIS A 1171 polymer cement mortar.
Adhesion strength: sandblasting concrete plate of horizontal 30 × vertical 30 × 6cm thick primer - (ethylene vinyl acetate based emulsion) coated with a brush so that the 150 g / m ^2, coating repair mortar so that 2cm thickness The surface was soldered to make a specimen. After 28 days of age, the core was cut with a high speed cutter to the ground concrete part with a coring and drilled, and a special drawing jig was attached and measured with a Kenken-type adhesion tester.

According to Table 2, it can be seen that by using the shrinkage reducing agent, the rate of change in length is reduced, and the shrinkage reducing effect is exhibited. Further, it can be seen that the adhesion strength is sufficient and it is integrated with the housing.

"Experiment 3"
The same procedure as in Example 1 was conducted except that the amount of fibers shown in Table 2 was added to 100 parts of the rapid hardening polymer cement mortar composition of Experiment No. 1-7 using clinker D, and the bending toughness of mortar and The adhesion strength was measured in the same manner as in Experimental Example 2. The results are shown in Table 6.

(Materials used)
Fibers: Vinylon fiber, fiber length 6 mm, fiber diameter 0.027 mm, convergence type, commercial product bending toughness: compliant with JSCE G552. The curing method was air curing in a room at a temperature of 20 ° C. and a humidity of 60%. The measurement material age was 28 days.

  According to Table 3, it can be seen that the bending toughness is improved by adding fibers.

  By adopting the quick-hardening polymer cement mortar composition of the present invention, even if stored for a long period of time, it exhibits mortar properties almost equivalent to those immediately after production, and exhibits excellent effects such as not damaging the product value. Suitable for civil engineering and construction fields.

Claims (4)

Quick hardening polymer cement mortar composition containing cement and polymer, fine aggregate, super fast hardening clinker, gypsum and setting regulator, and the super fast hardening clinker is a CaO-Al ₂ O ₃ based super fast hardening clinker containing carbonic acid component object. The rapid hardening clinker according to claim 1, comprising 29.9 to 65% of CaO, 29.9 to 70% of Al ₂ O ₃ and 0.1 to 5% of a carbonic acid component in terms of CO _2. Hard polymer cement mortar composition. The rapid hardening polymer cement mortar composition according to claim 1 or 2, comprising a shrinkage reducing agent. The rapid-hardening polymer cement mortar composition according to any one of claims 1 to 3, comprising fibers.