JP2010241618A - Super-quick hardening, underwater non-separable cement composition; super-quick hardening, underwater non-separable premixed mortar composition; and underwater non-separable grout mortar - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a super-quick hardening, underwater non-separable cement composition; a super-quick hardening, underwater non-separable premixed mortar composition; and a super-quick hardening, underwater non-separable grout mortar which have excellent underwater non-separability, advance the opening time of a construction site, and furthermore can achieve sufficient strength development for their hardened bodies. <P>SOLUTION: The super-quick hardening, underwater non-separable cement composition includes cement, calcium aluminate, gypsum, a powdery thickener containing an alkyl allyl sulfonate and an alkyl ammonium salt, a setting modifier and a polycarboxylic acid-based water reducer. Furthermore, the super-quick hardening, underwater non-separable cement composition is made by containing a silicone-based defoamant and a gas foaming substance. The super-quick hardening, underwater non-separable premixed mortar composition is produced by containing the super-quick hardening, underwater non-separable cement composition and fine aggregates; and the super-quick hardening, underwater non-separable grout mortar is produced by mixing the super-quick hardening, underwater non-separable premixed mortar composition and water. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention mainly relates to an ultrafast hard water inseparable dynamic cement composition, an ultrafast hard water inseparable premixed mortar composition, and an ultrafast hard water inseparable mainly used in the underwater grout in the civil engineering and construction industry. Related to sex grout mortar.

When placing mortar / concrete underwater in rivers or ocean engineering works, it is important to minimize contact with surrounding water and minimize material separation.
It has been practiced to place concrete blended concrete by a concrete pump method or tremy method. However, each method has a large material separation, and the water pollution at the installation site has been a problem.

Therefore, it improves the performance of concrete itself and improves the material separation resistance of concrete in water. It is a water-insoluble separable admixture based on cellulose-based and acrylic water-soluble polymers. A construction method has been proposed in which a special concrete is placed in water using a grouting material and underwater construction (Non-patent Document 1, Patent Document 1, Patent Document 2).
This formulation using an inseparable admixture in water increases the viscosity of the mortar / concrete due to the thickening effect of the water-soluble polymer. There was a problem that caused.

  Also, underwater construction does not require compaction, so good fluidity is required.Therefore, due to the addition of a large amount of water reducing agent and the increase in unit water volume, the setting time is delayed and the compressive strength is remarkably exhibited. There was also a problem of lowering.

  On the other hand, after kneading a binder such as cement, water, fine aggregate, an anionic aromatic compound, and a carboxy group-containing polyether-based water reducing agent, a cationic surfactant is added and kneaded again. A high fluidity mortar composition imparted with separability has also been proposed (Patent Document 3).

Concrete Library No. 67, Underwater inseparable concrete design and construction guidelines (draft), Japan Society of Civil Engineers, 1991

Japanese Patent Application Laid-Open No. 07-138055 JP 2007-261721 A JP 2006-176597 A

  The present invention provides a super-fast hard water non-separable dynamic cement composition, which has good water inseparability, accelerates the opening time of the construction site, and can achieve sufficient strength development of the hardened body. A medium non-separable premix mortar composition and an ultra-fast hard water non-separable grout mortar are provided.

  That is, the present invention is (1) super speed containing a powdery thickener containing a cement, calcium aluminate, gypsum, alkylallylsulfonate and alkylammonium salt, a setting regulator, and a polycarboxylic acid water reducing agent. It is a hard water inseparable cement composition, (2) is an ultrafast hard water inseparable cement composition of (1) further comprising a silicone-based antifoaming agent, and (3) calcium aluminate is Any one of (1) to (3), which is an amorphous calcium aluminate (1) or (2) ultrafast hard water inseparable cement composition, and further comprises a gas foaming substance. The ultrafast hard water inseparable cement composition of (5) (1) to (4), the ultrafast hard water comprising the ultrafast hard water inseparable cement composition and fine aggregate Inseparable process A mix mortar composition, (6) (5) of the super fast hard water nondisjunction Premix mortar composition and an ultra fast hard water formed by kneading a water-separating grout mortar.

  The underwater inseparable cement composition of the present invention is in a powder form and can be dry blended, and as a premix product, it is only necessary to prepare and mix water in the field construction, so that workability is improved, In addition, it has excellent non-separability and fluidity in water, has sufficient strength and no shrinkage not only in the air but also in water, and shortens the time for taking measures to prevent outflow even in locations with water flow. There is a remarkable effect of being able to.

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

  As the cement used in the present invention, various portland cements such as normal, early strength, very early strength, low heat, and moderate heat, various mixed cements obtained by mixing these portland cements with blast furnace slag, fly ash, or silica, , Limestone powder, filler cement mixed with blast furnace slow-cooled slag fine powder, environmentally friendly cement manufactured using various industrial wastes as the main raw material, so-called eco-cement, and so on. More than species can be used. In the present invention, it is preferable to select ordinary Portland cement or early-strength Portland cement from the viewpoint of initial strength development and material separation resistance.

The calcium aluminate used in the present invention is a general term for compounds mainly composed of CaO and Al ₂ O ₃ , and specific examples thereof include, for example, CaO · 2Al ₂ O ₃ , CaO · Al ₂ O _3. 12CaO · 7Al ₂ O ₃ , 11CaO · 7Al ₂ O ₃ · CaF ₂ , 3CaO · 3Al ₂ O ₃ · CaF _{2 and} other crystalline calcium aluminates and CaO and Al ₂ O ₃ components Examples include amorphous compounds as components. Among, CaO / _Al 2 _{O 3} molar ratio is preferably calcium aluminate in the range of 0.75~3, CaO / _Al 2 _{O 3} molar ratio is more preferably from 1 to 2. If the CaO / Al ₂ O ₃ molar ratio is less than 0.75, sufficient initial strength development may not be obtained. Conversely, if the CaO / Al ₂ O ₃ molar ratio exceeds 3, sufficient fluidity or good Usage time may not be obtained.
In addition, the calcium aluminate is preferably amorphous, and if it is crystalline, sufficient strength may not be obtained.

Calcium aluminate (hereinafter referred to as CA) as a method of obtaining a include a method obtained by heat-treating the like CaO material and Al ₂ O ₃ material by a rotary kiln or an electric furnace.
Examples of the CaO raw material for producing CA include calcium carbonate such as limestone and shells, calcium hydroxide such as slaked lime, and calcium oxide such as quick lime.
Examples of the Al ₂ O ₃ raw material include industrial by-products called bauxite and aluminum residual ash.

When CA is obtained industrially, impurities may be contained. Specific examples thereof include, for example, SiO ₂ , Fe ₂ O ₃ , MgO, TiO ₂ , MnO, Na ₂ O, K ₂ O, Li ₂ O, S, P ₂ O ₅ , and F. The presence of these impurities is not particularly problematic as long as the object of the present invention is not substantially impaired. Specifically, there is no particular problem if the total of these impurities is in the range of 10% or less.

Also, CA the present invention, as a compound, calcium such as _{4CaO · Al 2 O 3 · Fe} 2 O 3, 6CaO · 2Al 2 O 3 · Fe 2 O 3, and _{6CaO · Al 2 O 3 · 2Fe} 2 O 3 Calcium ferrite such as aluminoferrite, 2CaO · Fe ₂ O ₃ and CaO · Fe ₂ O ₃ , calcium aluminosilicate such as gelenite 2CaO · Al ₂ O ₃ · SiO ₂ and anorthite CaO · Al ₂ O ₃ · 2SiO ₂ , melvinite 3CaO · MgO · 2SiO _2, Akerumanaito 2CaO · MgO · 2SiO _2, and Monte calcium magnesium silicate, such as celite CaO · MgO · SiO _2, tri-calcium silicate 3CaO · SiO _2, dicalcium silicate 2CaO · SiO _2, Rankinai DOO 3CaO · 2SiO _2, and wollastonite calcium silicates and night CaO · SiO _2, calcium titanate CaO · TiO _2, free lime, and, leucite _{(K 2 O, Na 2 O} ) · Al 2 O 3 · SiO 2 In the present invention, these crystalline materials or amorphous materials can be mixed.

Although the particle size of the CA of the present invention is not particularly limited, it is usually preferably 3,000 to 9,000 cm ² / g, preferably 4,000 to 8,000 cm in terms of the specific surface area of the brain (hereinafter referred to as the “brane value”). ² / g is more preferable. If it is less than 3,000 cm ² / g, the initial strength development may not be sufficient, and if it exceeds 9,000 cm ² / g, it may be difficult to ensure fluidity and pot life.

In the present invention, from the viewpoint of securing fluidity and pot life, it is preferable to use a CA with a loss on ignition of 1% or more, more preferably a CA with a loss on ignition of 2% or more. preferable.
A method for reducing the ignition loss to 1% or more is not particularly limited, and examples thereof include a method for supplying moisture and moisture, a method for supplying carbon dioxide, and the like.

  The gypsum used in the present invention is a generic term for each gypsum of anhydrous, semi-water, or dihydrate, and is not particularly limited, but from the viewpoint of strength development, anhydrous gypsum or semi-water gypsum Use is preferred, and the use of anhydrous gypsum is more preferred.

Although the particle size of gypsum is not particularly limited, from the viewpoint of ensuring dimensional stability and fluidity, the brane value is usually preferably from 3,000 to 9,000 cm ² / g, and from 4,000 to 8,000 cm. ² / g is more preferable.

  The blending ratio in 100 parts of the binder composed of cement, CA, and gypsum in the super fast cement composition of the present invention is excellent in fluidity and has a strength that can be released in a short time while ensuring sufficient pot life. In order to express, 50-90 parts of cement, 5-25 parts of CA, and 5-25 parts of gypsum are preferable.

  Here, the blending ratio of CA and gypsum is 30 to 70 parts of CA and 100 to 70 parts of quick hardening component consisting of CA and gypsum from the viewpoint of insufficient initial strength and dimensional stability. Part is preferable, CA 40-60 parts, gypsum 60-40 parts is more preferable.

  The blending ratio of the rapid hardening component is preferably 10 to 50 parts, more preferably 20 to 40 parts in 100 parts of the binder, from the viewpoints of initial strength development, material separation resistance, securing pot life, and dimensional stability. preferable.

In the present invention, a thickener is used in order to impart inseparability in water.
The thickener used in the present invention is a powdery thickener containing an alkylallyl sulfonate and an alkylammonium salt. When both come into contact with water, the thickener is associated by intermolecular interaction to form a string. These micelles are formed, and the rheology modification effect is expressed by their structure.
The blending ratio of the alkyl allyl sulfonate and the alkyl ammonium salt is not particularly limited as long as string-like micelles can be formed. Usually, the active ingredient is preferably in the range of 1/10 to 10/1 in terms of mass ratio of alkylallyl sulfonate / alkyl ammonium salt.
The amount of the powder thickener used is preferably 0.10 to 0.50 part, more preferably 0.15 to 0.45 part with respect to 100 parts of the binder from the viewpoint of inseparability in water and fluidity. preferable.

In the present invention, a polycarboxylic acid-based water reducing agent is used to impart fluidity.
The form of the polycarboxylic acid-based water reducing agent may be either liquid or powder, but since the cement composition is blended as a dry blend, a powder is used.
The amount of the polycarboxylic acid-based water reducing agent used is preferably 0.05 to 0.30 parts with respect to 100 parts of the binder from the viewpoints of fluidity, generation of bubbles, inseparability in water, and setting time.

In the present invention, it is possible to use a silicone-based antifoaming agent containing dimethylcyclohexane as an active ingredient for the purpose of defoaming the entrained air and preventing the strength from coming from the air entrainment. Like the water reducing agent, the form is either liquid or powder. However, since the cement composition is blended as a dry blend, a powder is used.
The amount of the silicone-based antifoaming agent used is preferably 0.005 to 0.10 parts with respect to 100 parts of the binder from the viewpoints of reduction in air amount, compressive strength, and inseparability in water.

The setting regulator used in the present invention is not particularly limited. Specific examples thereof include organic acids such as oxycarboxylic acids such as citric acid, tartaric acid, malic acid, gluconic acid, and succinic acid or salts thereof such as sodium, potassium, calcium, magnesium, ammonium, and aluminum, and carbonic acid. Examples thereof include alkali carbonates of sodium, potassium carbonate, and lithium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, and ammonium bicarbonate. One or more of these can be used. .
In the present invention, the combined use of an organic acid and an alkali carbonate is preferable from the viewpoint of satisfying both sufficient pot life and initial strength development.

  Although the usage-amount of a setting regulator is not specifically limited, From a viewpoint of pot life or intensity | strength development property, 0.1-2 parts are preferable with respect to 100 parts of binder normally, 0.3- One part is more preferred.

When using the underwater inseparable cement composition of the present invention as a grout material, a gas foam material is used to integrate with the structure or to prevent the grout mortar that has not yet solidified from sinking or shrinking. To do.
Examples of gas foaming substances include flaky aluminum powder surface-treated with stearic acid, aluminum powder produced by an atomizing method, substances that foam nitrogen gas in an alkaline atmosphere, such as azo compounds, nitroso compounds, and hydrazine derivatives. Percarbonate such as sodium percarbonate, potassium percarbonate and ammonium percarbonate, perborate such as sodium perborate and potassium perborate, permanganate such as sodium permanganate and potassium permanganate In addition, peroxide substances such as hydrogen peroxide can be used. This nitrogen gas foaming material may generate ammonia gas and carbon dioxide gas in addition to nitrogen gas.
The amount of the gas foaming material used is 0.0005 to 0.003 part for the aluminum powder and 0.01% for the nitrogen gas foaming material with respect to 100 parts of the binder from the viewpoint of the expansion coefficient of the cured body and the strength of the cured body. ~ 0.5 part, and the peroxide is preferably 0.01-0.1 part.

The fine aggregate used in the present invention plays an important role in terms of reducing the calorific value and dimensional change and ensuring durability, and specific examples include river sand, mountain sand, and sea sand, Examples include quartz sand-based fine aggregate, limestone-based fine aggregate, blast furnace granulated slag-based fine aggregate, and recycled aggregate. From the viewpoint of premixing, dry fine aggregate is preferred.
The particle size of the fine aggregate is preferably 1.2 to 3.0, more preferably 1.5 to 2.7 in terms of coarse particle ratio (FM), from the viewpoint of fluidity, inseparability in water, and strength. .
The amount of the fine aggregate used is preferably 50 to 200 parts with respect to 100 parts of the bond from the viewpoint of thermal cracking and compressive strength.

In order to suppress the heat of hydration when placing in large quantities, it is possible to mix coarse aggregate and use it as concrete.
As coarse aggregates, slag aggregates defined by JIS A 5011-1, JIS A 5011-2, JIS A 5011-3, and JIS A 5011-4, as well as crushed stones defined by JIS A 5005, Ordinarily said boulders and bean gravel can also be used.
From the viewpoint of workability, the particle size of the coarse aggregate is preferably 25 mm or less, more preferably 20 mm or less, in terms of Gmax.
The mixing ratio of the fine aggregate and the coarse aggregate in the concrete is preferably s / a (fine aggregate ratio) of 45 to 75% from the viewpoints of suppression of heat of hydration, workability, and fluidity.

  The amount of water used is not particularly limited because it varies depending on the blending ratio of each material, but from the viewpoint of fluidity and strength development, it is usually preferably 30 to 50% in terms of water binder, 35 to 35%. 45% is more preferable.

In the present invention, fly ash can be blended for the purpose of improving fluidity.
The fly ash is preferably the fly ash type I described in JIS A 6201.
The amount of fly ash can be used by replacing 5 to 20 parts with cement in the binder.

  In the present invention, the mixing order of the materials is not particularly limited as long as they are mixed in a powder form and finally premixed.

  In the present invention, any existing apparatus such as a tilting cylinder mixer, an omni mixer, a Henschel mixer, a V-type mixer, and a Nauta mixer can be used as a mixing apparatus for each material.

  Hereinafter, although further demonstrated based on the experiment example of this invention, this invention is not limited to these.

"Experiment 1"
70 parts of cement, 15 parts of CA and 15 parts of gypsum as shown in Table 1, 100 parts of binder, thickener and water reducing agent A shown in Table 1 and 0.8 part of a setting modifier Then, a cement composition was prepared. 80 parts of fine aggregate was added to 100 parts of the binder of the prepared cement composition and mixed with a V-type mixer to prepare a mortar composition.
Under an environment of 20 ° C., 100 parts of the binder of the mortar composition was kneaded with 38 parts of water to prepare grout mortar.
The prepared grout mortar was evaluated for fluidity, non-separability in water, pot life, and compressive strength. The results are also shown in Table 1.

<Materials used>
Cement: Ordinary Portland cement, commercially available, Blaine value 3,300 cm ² / g
CA i: CaO / Al ₂ O ₃ molar ratio 1.0, loss on ignition 1.0%, crystalline, main component CaO · Al ₂ O ₃ , Blaine value 5,000 cm ² / g
CA B: CaO / _Al 2 _{O 3} molar ratio 1.50, loss on ignition 1.0%, crystalline, composed mainly CaO · _Al 2 _{O 3} and 12CaO · _7Al 2 _{O 3,} Blaine 5,000 cm ² / g
CA C: CaO / _Al 2 _{O 3} molar ratio 1.70, loss on ignition 1.0%, crystalline, composed mainly CaO · _Al 2 _{O 3} and 12CaO · _7Al 2 _{O 3,} Blaine 5,000 cm ² / g
CA D: CaO / _Al 2 _{O 3} molar ratio 2.00, loss on ignition 1.0%, crystalline, composed mainly CaO · _Al 2 _{O 3} and 12CaO · _7Al 2 _{O 3,} Blaine 5,000 cm ² / g
CA Ho: CaO / Al ₂ O ₃ molar ratio 1.50, loss on ignition 1.0%, amorphous, 3% of reagent grade 1 silica is added to CA and melted at 1,650 ° C. Quenched and synthesized, brain value 5,000cm ² / g
To CA: CaO / Al ₂ O ₃ molar ratio 1.70, loss on ignition 1.0%, amorphous, 3% of reagent grade 1 silica added to CA C, melted at 1,650 ° C., Quenched and synthesized, brain value 5,000cm ² / g
CA DOO: CaO / _Al 2 _{O 3} molar ratio 2.00, loss on ignition 1.0%, amorphous, the addition of reagent first grade silica 3% CA two, melted at 1,650 ° C., Quenched and synthesized, brain value 5,000cm ² / g
CAchi: Moisture is applied to CA and the loss on ignition is set to 2.0%, brain value 5,000 cm ² / g
Gypsum: anhydrous gypsum, commercially available, brain value 4,000 cm ² / g
Thickener: powdery thickener containing alkyl allyl sulfonate and alkylammonium salt, commercially available water reducing agent A: powdered polycarboxylic acid-based water reducing agent, commercial product coagulation modifier: reagent grade 1 citric acid 25 A mixture of 75 parts of reagent and 75 parts of first grade potassium carbonate fine aggregate: lime sand, F.R. M.M. = 2.02
Water: tap water

<Measurement method>
Flowability: A flow cone having an inner diameter of 50 mm and a height of 100 mm was filled with mortar immediately after kneading, and the spread of the mortar was measured when 3 minutes passed after the cone was pulled up.
Underwater inseparability: 800 ml of water is put into a 1000 ml beaker, and about 200 ml of mortar is dropped into the beaker from a funnel having a diameter of 18 mm, and JSCE-D104 1999 “Underwater inseparable admixture quality standard for concrete is attached. The water was collected in accordance with “Method 2 for testing the degree of inseparability of underwater concrete in water”, and the pH was measured. The evaluation is good <non-separability in water <bad = small <pH <large.
Pot life: Using a self-recording temperature recorder, the time until the temperature of the mortar rose by 2 ° C. from the kneading was defined as the pot life.
Compressive strength: Using a mold of φ50 × 100 mm, a test specimen was produced in a constant temperature room at 20 ° C., and the compressive strength at the age of 3 hours was measured.

"Experimental example 2"
A binder consisting of cement, CA and gypsum shown in Table 2 and 100 parts of binder are combined with 0.30 parts of thickener, 0.15 parts of water reducing agent A, and 0.8 parts of a setting adjuster. Except that the cement composition was prepared, the same procedure as in Experimental Example 1 was conducted to evaluate the fluidity, non-separability in water, pot life, compressive strength, and resistance to washing out of running water of the prepared grout mortar. The results are also shown in Table 2.

<Measurement method>
Resistance to washing out with running water: Attach a mold 30cm x 30cm x thickness 5cm at the bottom of the water channel, mortar it into the mold, and flow water at a flow rate of 5m / s 1 hour after placing, visually check the turbidity of the flowing water It was evaluated with. The case where the turbidity of water is severe is impossible, the case where there is turbidity of water is acceptable, the case where there is a little turbidity of water is good, and the case where there is no turbidity of water is excellent.

"Experiment 3"
70 parts of cement, 15 parts of CA and 15 parts of gypsum, and 100 parts of binder, thickener 0.30 parts and water reducing agent A 0.15 parts, antifoaming agents shown in Table 3, And gas foaming material, and except that 80 parts of fine aggregate was used to prepare grout mortar, the same procedure as in Experimental Example 1 was carried out, the fluidity of the prepared grout mortar, inseparability in water, pot life, Compressive strength and initial expansion rate were evaluated. The results are also shown in Table 3.

<Materials used>
Antifoaming agent: silicone-based antifoaming agent, commercial gas foaming material A: stearic acid-treated aluminum powder, commercial gas foaming material B: azodicarbonamide, commercial product

<Measurement method>
Initial expansion rate: mortar kneaded in a mold of φ5 × 10 cm, and measured with a photosensor for the rate of change in length in the vertical direction from just after placement until the age of 24 hours. Side, + is the expansion side

"Experimental example 4"
70 parts of cement, 15 parts of CA and 15 parts of gypsum, and 100 parts of binder, 0.030 part of defoaming agent, 0.001 part of gas foaming material A, thickener shown in Table 4 Fluidity, water inseparability, pot life, compressive strength of the prepared grout mortar, except that the grout mortar was prepared using water, a water reducing agent, fine aggregate and water. Evaluated. The results are also shown in Table 4.

Water reducing agent B: Powdered naphthalene water reducing agent, commercial water reducing agent C: Powdered melamine water reducing agent, commercial product

  The grout mortar using the underwater inseparable cement composition of the present invention is in a powder form and can be dry blended. As a premix product, the workability in field construction is improved. Excellent inseparability and fluidity, has sufficient strength development and non-shrinkage not only in the air but also in water, and can shorten the time to take measures to prevent outflow even in places with water flow Since it has a remarkable effect, it can be widely applied in the civil engineering and construction fields.

Claims (6)

  An ultra-fast hard water inseparable cement composition containing cement, calcium aluminate, gypsum, a powdery thickener containing an alkylallylsulfonate and an alkylammonium salt, a coagulation modifier, and a polycarboxylic acid water reducing agent. Furthermore, the super-fast hard water non-separable cement composition of Claim 1 formed by containing a silicone type antifoamer.   The ultra-fast hard water inseparable cement composition according to claim 1 or 2, wherein the calcium aluminate is an amorphous calcium aluminate.   The super-fast hard water inseparable cement composition according to any one of claims 1 to 3, further comprising a gas foaming substance.   An ultrafast hard water inseparable premixed mortar composition comprising the ultrafast hard water inseparable cement composition according to any one of claims 1 to 4 and a fine aggregate.   An ultrafast hard water inseparable grout mortar obtained by kneading the ultrafast hard water inseparable premix mortar composition according to claim 5 and water.