JPH10324551A - Grout composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compsn. which shows a flowing effect even at a low temp. while it maintains high strength developing property by compounding a specified amt. of an admixture containing a copolymer comprising specified proportions of N-substd.-α,β-unsatd. monocarboxylic acid amide deriv., methacrylic acid (salt) and acrylic acid (salt) into a grout material comprising cement and a specified amt. of sand. SOLUTION: An admixture containing the copolymer described below is compounded by 0.2 to 2.0 wt.% or a cement into a grout material comprising cement and 100 to 400 wt.% of sand to the cement. The copolymer consists of a N-substd.-α,β-unsatd. monocarboxylic acid amide deriv. (A) expressed by the formula, methacrylic acid (salt) (B) and acrylic acid (salt) (C) with 55/45 to 85/15 molar ratio of A/B and 99.5/0.5 to 55/45 molar ratio of B/C. The copolymer has 60,000 to 220,000 weight average mol.wt. In the formula, R<1> is H, lower alkyl; R<2> is 1 to 4C alkyl; X is H, alkali (earth) metal, (org.)ammonium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grout composition, and more particularly to a cement grout composition comprising cement and sand that can be used if the kneading temperature is about 5 ° C. or higher.

[0002]

2. Description of the Related Art Conventionally, grouting materials have been used for bridge bearings, injection of machines under a base plate, fixing of anchor bars, injection of lock anchors, filling of gaps in a reverse hitting method, reinforcing and repairing structures, and the like. I have.

[0003] Various grout materials have been developed so far, but cement grout materials are most widely used, and are composed of cement and sand as raw materials in which various additives are compounded according to applications and purposes. Have been. JP Hei 3
The grout material disclosed in JP-A-199285 is cement, sand, and fluid coke [a by-product produced when thermal decomposition of heavy hydrocarbons (for example, pitch) is carried out by fluid coking method. 300 μm, water content adjusted to 3% by weight or less, and used as an additive for cement-based grouting material.
The value of m is more effective. ] A grout composition comprising a grout material comprising a high-performance water reducing agent containing polyalkylallyl sulfonate and / or melamine formaldehyde resin sulfonate as a main component in an amount of 3 to 35% by weight based on fluid coke. , High fluidity, fresh non-shrinkage (non-bleeding and non-sinking),
It has characteristics such as excellent strength development and is practically used as a non-shrinkable grout material.

[0004]

However, in the case of the above-mentioned grout material which requires much higher fluidity than ordinary concrete, the influence of temperature on the fluidity becomes remarkable. For example, grout material is used for construction in winter. In this case, a high-performance water reducing agent containing a polyalkylallyl sulfonate and / or a melamine formaldehyde resin sulfonate as a main component disclosed in Japanese Patent Application Laid-Open No. 3-199285 has a problem that fluidity is remarkably reduced. I understand.

[0005] In general, grout is applied by pouring using a pump or pouring by gravity. For this reason, immediately after grout production, KODAN-304 was used in order to confirm that a predetermined fluidity was obtained.
It is performed managed by J ₁₄ funnel method as defined in -1976.

[0006] In the conventional cement-based grout material described above, when the kneading temperature is 15 ° C or less, even if a predetermined fluidity can be obtained immediately after production, the fluidity is not maintained when the mixture is allowed to stand for 20 minutes or more for the convenience of construction. significantly decreased, hardly flowing down from J ₁₄ funnel significant flow losses were observed. In order to solve this problem, they have been kneaded again at the time of use or increased by adding the high-performance water reducing agent. However, when the temperature is further lowered or the standing time is prolonged, the desired fluidity cannot be obtained even if the mixture is mixed again or the addition rate of the high-performance water reducing agent is increased, and the high-performance water reducing agent is not obtained. If the amount is too large, separation phenomena such as bleeding and aggregate settlement may occur.

[0007] An object of the present invention is to provide a cement grout composition capable of maintaining high strength development and maintaining high fluidity in order to solve the above-mentioned conventional problems.

[0008]

Means for Solving the Problems The present inventors have maintained high strength development by using an admixture containing a specific vinyl copolymer in place of the above-mentioned high-performance water reducing agent, and have achieved a 30 It has been found that a cement-based grout material having a low flow loss and high fluidity can be obtained if the kneading temperature of the grout material is kept at about 5 ° C. or more even after standing for about a minute. Completed.

That is, the present invention relates to a cement grout material comprising 100% to 400% by weight of sand with respect to cement and (a) N-substituted-α, β represented by the following general formula (1): A copolymer of an unsaturated monocarboxylic acid amide derivative, (b) methacrylic acid or a salt thereof, and (c) acrylic acid or a salt thereof, wherein the copolymerization molar ratio is (a) / (b) = 55 / 45-85 / 15, (b) /
(C) = 99.5 / 0.5 to 55/45,
And a weight average molecular weight of 60,000 to 220,000.
A grout composition characterized in that a cement admixture containing a copolymer (hereinafter referred to as "special admixture") is blended in an amount of 0.2 to 2.0% by weight based on cement. .

[0010]

Embedded image (Wherein, R ^{1 represents} hydrogen or a lower alkyl group, R ² represents a linear or branched alkyl group having 1 to 4 carbon atoms, X represents hydrogen, an alkali metal, an alkaline earth metal, ammonium or an organic ammonium group. )

In the above, the number of carbon atoms of the lower alkyl group of R ¹ is preferably in the range of 1 to 6, and particularly preferably a methyl group. Further, the grout composition of the present invention preferably further contains 3 to 10% by weight of fluid coke based on cement.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the grout composition of the present invention, the above-mentioned special admixture is added in place of the conventional high-performance water reducing agent, whereby the flow effect is maintained even at a low temperature and the flow loss is suppressed. It seems to be.

Therefore, the rate of addition of the special admixture to the cement is an important factor, and the mixing ratio of the special admixture is 0.2 to 2.0% by weight, preferably 0.5 to 2.0% by weight of the cement.
1.5% by weight. If it is less than 0.2% by weight, a predetermined fluidity cannot be obtained in a wide temperature range of about 5 ° C. or more, and there is no effect of suppressing the generation of bleeding water. Excessive compounding is not preferred because the strength of the cured product is reduced.

Known cement and sand are used for the grout composition of the present invention. For example, cements include various portland cements, mixed cements, alumina cements and the like, and sands used in conventional cement grout materials such as river sand, sea sand, land sand, silica sand, and crushed sand may be used. The particle size of the cement or sand is not particularly limited, and may be in the conventional range.

The special admixture used in the present invention is:
(A) N-substituted-α, β represented by the above general formula (1)
A copolymer of an unsaturated monocarboxylic acid amide derivative, (b) methacrylic acid or a salt thereof, and (c) acrylic acid or a salt thereof, wherein the copolymerization molar ratio of the monomers is (a) / ( b) = 55 / 45-85 / 15, (b) /
(C) = 99.5 / 0.5 to 55/45,
And a weight average molecular weight of 60,000 to 220,000.
Is a copolymer of

N-substituted -α of the above monomer component (a),
Examples of the β-unsaturated monocarboxylic amide derivative include 2-
Acrylamide-2-methylpropanesulfonic acid, 2-
Examples include acrylamidoethanesulfonic acid, 2-methacrylamidoethanesulfonic acid, 3-methacrylamidopropanesulfonic acid, and salts thereof.

As the monomer component (b) of the copolymer, methacrylic acid or a salt thereof is used. Acrylic acid or a salt thereof is used as the monomer component (c) of the copolymer.

The salts in these monomer components include:
Alkali metal salts, alkaline earth metal salts, and organic ammonium salts such as ammonium salts, amine salts, and alkanolamine salts are used. In the copolymer of the present invention, the copolymerization molar ratio of the monomer components (a) and (b) is (a).
/ (B) = 55 / 45-85 / 15, preferably 60 /
It needs to be in the range of 40 to 80/20. When the copolymerization molar ratio exceeds 85/15, the fluidity is remarkably reduced. When the copolymerization molar ratio is less than 55/45, the fluidity is remarkably reduced and the compressive strength is also reduced.

The copolymerization molar ratio of the monomer components (b) and (c) significantly affects the mixing time and the fluidity. In order to shorten the mixing time from 1 minute 30 seconds to about 2 minutes, (b) / (c) = 99.5 / 0.5 to 55
/ 45, preferably in the range of 97/3 to 65/35. Copolymer molar ratio of 99.5 / 0.5
If it is more than 2 minutes, a long time of 2 minutes or more is required for mixing in order to secure fluidity. If the ratio is less than 55/45, the fluidity is significantly reduced.

Further, the copolymer in the present invention needs to have a weight average molecular weight in the range of 60,000 to 220,000, preferably 80,000 to 160,000.
000. When the weight average molecular weight exceeds 220,000, the viscosity of the aqueous solution of the admixture increases, making it difficult to handle, and the fluidity is significantly reduced. Molecular weight 60,00
If it is less than 0, the fluidity decreases.

The copolymer in the present invention can be synthesized by ordinary radical polymerization. However, as the polymerization initiator, an oxidation-reduction initiator obtained by combining a persulfate and a sulfite is used. ) And (c) are more preferably obtained by copolymerizing the components.

As the persulfate, sodium persulfate, ammonium persulfate, potassium persulfate and the like are used. As the sulfites, sulfites, bisulfites or pyrosulfites are used, and as these salts, sodium, potassium, ammonium and the like are used. In particular, a redox polymerization initiator obtained by combining ammonium persulfate and potassium bisulfite is preferable.

At the time of the copolymerization reaction, an initiator may be simultaneously added to the mixture of the components (a), (b) and (c), and the components (a), (b) and The component (c) and the initiator may be continuously added at a predetermined molar ratio.

In order to obtain a copolymer having a predetermined weight average molecular weight, the concentration of the persulfate is set to be 0.1 to 1 mol of the vinyl monomer.
01 to 0.2 mol is suitable, preferably 0.02 to 0.2 mol.
0.1 mol. If the persulfate concentration exceeds 0.2 mol, the weight average molecular weight will be lower than the lower limit and the fluidity will decrease.
On the other hand, if it is less than 0.01 mol, the weight average molecular weight exceeds the upper limit, the viscosity of the aqueous solution of the admixture becomes high, handling becomes difficult, and the flowability is also lowered.

The sulfite is used in an amount of 0.1 to 1 mole of persulfate.
It is preferable to use them together in a proportion of 1 to 5 mol, preferably 0.5 to 2 mol. When this amount exceeds 5 mol, the salt concentration of the obtained copolymer becomes high, and the durability of the grout material is reduced. On the other hand, if it is less than 0.1 mol, the polymerization rate is reduced, and the fluidity is reduced.

The polymerization temperature is preferably from 15 to 70 ° C. When the polymerization temperature exceeds 70 ° C., thermal decomposition of the persulfate occurs, the polymerization rate decreases, and the initial fluidity decreases. Further, even when the polymerization temperature is lower than 15 ° C., the polymerization rate decreases, and the same phenomenon occurs. The polymerization can be carried out by aqueous solution polymerization. The time required for the polymerization is usually about 20 minutes to 4 hours, but is appropriately selected depending on the monomer ratio, the aqueous solution concentration and the like. Further, the pH at the time of polymerization is preferably 2 or more. Furthermore, as long as the effects of the present invention are not impaired, other copolymerizable monomer components, such as styrene, may be added to the polymerization components (a), (b) and (c).
Acrylonitrile, acrylamide, acrylate, methacrylate, vinyl acetate, and the like may be copolymerized.

In the grout composition of the present invention, a fluid coke, an expanding agent or a thickener may be used to such an extent that the amount of water does not change, and may be used in combination with a special admixture. In particular, when used as a non-shrinkable grout material as disclosed in JP-A-3-199285, fluid coke is used in combination with a special admixture, and the fluid coke is added to the cement in an amount of 3 to 10% by weight. It is preferable to use them in combination.
If it is less than 3% by weight, sufficient non-shrinkage property cannot be obtained, and if it exceeds 10% by weight, the strength is reduced, and neither is preferable. Fluid coke is a by-product generated when heavy hydrocarbons (for example, pitch) are thermally decomposed by a fluid coking method, and has a particle size of 44 to 300 μm and a water content of 3% by weight or less. It is.

The mixing amount of sand is 100 to 4 with respect to cement.
00% by weight is preferred. Outside this range, the strength is reduced and the material is separated, which is not preferable. The grout composition of the present invention may be prepared by mixing cement, sand and a special admixture by a conventional method, and further, if necessary, an admixture such as fluid coke.As a mixing method, the special admixture is previously mixed. Any method such as a method of kneading the grout composition with water, a method of adding a special admixture when kneading the grout material with water excluding the special admixture, and a method of kneading with water in which the special admixture is previously dissolved. However, the present invention includes all cases where the composition as the grout composition of the present invention when used as a grout material is included in the present invention. In addition, the grout composition of the present invention may be used according to a conventional method of using a cement-based grout material.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. (1) Production of special admixture A pH 7.0 to 8.0 was prepared in a reactor having a reflux condenser of 2000 ml in capacity equipped with a reflux condenser, a dropping funnel and a gas inlet tube.
2.235 mol (512.3 g) of sodium 2-acrylamido-2-methylpropanesulfonate (AAMPS.Na) adjusted to 0, and 0.671 mol (72.6)
g) sodium methacrylate (MA.Na);
287 moles (27.0 g) of sodium acrylate (A
A.Na) -containing aqueous solution (1436.4 g) was charged and purged with nitrogen, and while flowing nitrogen, all the monomer aqueous solutions were mixed to adjust the pH to 7.0 to 8.0, and then the temperature was raised. When the temperature reached 45 ° C, potassium bisulfite dissolved in a small amount of water was added.
211 mol (25.3 g) and 0.211 mol (48.1 g) of ammonium persulfate dissolved in a small amount of water were added,
The polymerization was carried out for 2 hours while maintaining the polymerization temperature at 50 to 55 ° C.
In this case, 2-acrylamide-2 relative to the whole reaction system was used.
The sum of the concentrations of sodium methylpropanesulfonate, sodium methacrylate and sodium acrylate is 2
It was 8.4% by weight.

The weight average molecular weight of the copolymer thus obtained was 120,000 as measured by gel permeation chromatography (GPC). This copolymer is referred to as a special admixture A.

Further, by keeping the molar ratio of potassium bisulfite / ammonium persulfate at 1.0 and adjusting the molar ratio of this to the comonomer (3 types), special mixing of a predetermined weight average molecular weight can be achieved. Agents BP were prepared. That is, the addition ratio of potassium bisulfite and ammonium persulfate was kept constant, and the ratio of the copolymerized monomer was appropriately changed.
AMPS · Na / MA · Na ratio, MA · Na / AA · N
Special admixtures BP having different a ratios, weight average molecular weights, etc. were produced in the same manner.

(2) Production of grout material The special admixture shown in Table 1 was added to the following cement and sand.
~ P was added to produce a normal cement grout material containing no fluid coke. The mixer used may be any mixer that can produce ordinary mortar or concrete. Put cement sand, admixture, etc. into the mixer,
After kneading for 15 seconds, a predetermined amount of water was added and kneading was performed for 2 minutes. The addition rate of each special admixture was 1.0% by weight based on the cement. The addition rate of sand was kept constant at 100% by weight with respect to the cement. Then, the ordinary obtained cement-based grout material to which no fluid coke was added was used in Example 1 in the evaluation test of the cement-based grout material.
To 9 and Comparative Examples 1 to 6. Cement: Early strength Portland cement (manufactured by Nippon Cement Co., Ltd.) Silica sand: Silica sand NP-40 (manufactured by Nippon Plaster Co., Ltd.) In addition, the above cement and sand (80, 100, 250, 400, 450 with respect to cement as shown in Table 2) weight%
The above-mentioned special admixture F is added to the various sands added in the above-mentioned steps, and the addition ratio of the special admixture F is 0.1, 0.2, 1..
Normal grout materials were produced by adding at various addition rates of 0, 1.5, 2.0, and 2.2% by weight. And it provided to Examples 10-14 and Comparative Examples 7-16 in the evaluation test of the normal cement grout material which does not add fluid coke. Further, 100% by weight and 1.0% by weight of the following sand and the above-mentioned special admixture A were added to the cement shown below, respectively. Further, the fluidized coke shown below was mixed with the fluidized coke as shown in Table 3. A non-shrinkable grout material mixed with a conventional mixer was manufactured by changing the addition ratio. And it provided to Examples 15-20 and Comparative Examples 17-18 in the evaluation test of the non-shrinkage cement grout material which added fluid coke. Cement: Early strength Portland cement (Nippon Cement Co., Ltd.) Silica sand: Silica sand NP-40 (Nippon Plaster Co., Ltd.) Fluid coke: PLA (particle size: 74-149 μ, moisture:
0.7 wt%, I.C.P.R. Companies Ltd.) In the production of the three types of grout, a so water can flow time by J ₁₄ funnel immediately after production is 8 ± 1 sec I decided. As a comparative example, "Mighty 100" manufactured by Kao Corporation as a high performance water reducing agent containing polyalkylallyl sulfonate as a main component, and "Merment F-10" as a high performance water reducing agent containing melamine formaldehyde resin sulfonate as a main component. Was also used.

(3) Evaluation of Grout Material Except for the measurement of the kneading temperature, the test was carried out in accordance with the quality control test method of the non-shrink mortar of the Japan Highway Public Corporation “Non-shrink mortar standard” KODAN-304-1976. Measurement of kneading temperature An alcohol thermometer was used. In addition, the temperature in a table | surface is a kneading temperature of a grout material except the temperature at the time of expansion rate measurement (atmospheric temperature). It was by consistency testing method shown in Section 3.2 of the measurement the non-shrink mortar quality control testing method of flow time according to J ₁₄ funnel. When measuring after 30 minutes, no repetition was performed. In the table, those that are not fluidized are marked with “x”. Measurement of bleeding rate The bleeding test method described in section 3.3 of the above-mentioned non-shrink mortar quality control test method was used. Measurement of Expansion Ratio The expansion / shrinkage test method described in Section 3.4 of the above-mentioned non-shrink mortar quality control test method was used. Compressive strength test The compressive strength test method described in Section 3.6 of the non-shrink mortar quality control test method was used. Specimen dimensions are:
5 cm, height: 10 cm, molded, removed the next day, kneaded to a specified age, and cured in water at the temperature. Tables 1, 2, and 3 collectively show the obtained results.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

From the results of Tables 1 to 3, it was confirmed that the grout compositions of the examples of the present invention were cement grout materials having a wider usable temperature range than before.

[0038]

As described above, the grout composition of the present invention can be used for cement and cement in an amount of 100 to 400.
(A) an N-substituted-α, β-unsaturated monocarboxylic acid amide derivative represented by the general formula (1), and (b) methacrylic acid or a salt thereof. And (c) a copolymer of acrylic acid or a salt thereof, wherein the copolymerization molar ratio is (a) / (b) = 55/4.
5-85 / 15, (b) / (c) = 99.5 / 0.5-
55/45 and a weight average molecular weight of 6
By mixing a cement admixture containing a copolymer of 20,000 to 220,000 with 0.2 to 2.0% by weight based on cement, high strength development is maintained and high fluidity is maintained. It is possible to provide a cement grout composition that can be maintained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09K 17/22 C09K 17/22 P 17/44 17/44 P 17/48 17/48 P // C04B 103: 32 111: 70 C09K 103: 00

Claims (2)

[Claims] Claims: 1. Cement and 100 to cement
Cement grout made of 400% by weight of sand,
(A) N-substituted-α, β represented by the following general formula (1)
A copolymer of an unsaturated monocarboxylic acid amide derivative, (b) methacrylic acid or a salt thereof, and (c) acrylic acid or a salt thereof, wherein the copolymerization molar ratio is (a) / (b)
= 55 / 45-85 / 15, (b) / (c) = 99.5
A cement admixture containing a copolymer having a weight average molecular weight of 60,000 to 220,000 and a cement admixture of 0.2 to 2.0% by weight based on the cement. A grout composition characterized by being blended. Embedded image (In the formula, R ^{1 represents} hydrogen or a lower alkyl group R ² represents a linear or branched alkyl group having 1 to 4 carbon atoms X represents hydrogen, an alkali metal, an alkaline earth metal, ammonium or an organic ammonium group.) 2. The grout composition according to claim 1, further comprising 3 to 10% by weight of fluid coke based on the cement.