JPH01230455A - Extremely quick-setting nonshrink grout material - Google Patents

Abstract

PURPOSE:To form an extremely quick-setting nonshrink grout material having excellent fluidity, workability and quick setting properties, by blending an inorganic binder with a specific additive. CONSTITUTION:This extremely quick-setting nonshrink grout material is obtained by blending the following component A with a component B. The component A comprises 100 pts.wt. inorganic binder consisting of 30-80 pts.wt. Portland cement, 5-50wt.% alumina cement, 5-20wt.% gypsum and 1-20 pts. wt. calcium hydroxide and/or calcium carbonate. The component B comprises 0.01-2.0 pts.wt. hydroxycarboxylic acid and/or salt thereof, 0.001-0.5 pt.wt. zinc compound, 0.005-0.02 expanding material, 0.01-2.0 pts.wt. water reducing agent and 0.001-2.0 pts.wt. fluidizing agent. The group material can be optionally mixed with a bulk filler, fine aggregate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultra-fast hardening non-shrinkage grout material of a novel composition.

Prior art and its problems When installing mechanical equipment, civil engineering, and constructing architectural structures, there are always places that require joining.

Grout is a material used to make the joints more complete by filling the gaps in these structures, and in such joints shrinkage must be avoided as much as possible, so low Shrinkable or non-shrinkable grouts (hereinafter referred to as non-shrinkable grouts) are used. Non-shrinkage grout is prepared by kneading non-shrinkage grout material made of Portland cement, fine aggregate, expansive materials, various types of admixtures, etc. with water. Generally, when the inside diameter of the outflow pipe is 18 mm, the P funnel ( Flow time by PL8) is 14-2
2 seconds or J funnel when the lower end inner diameter is 14 mm (
J 14) is worked up so that the flow time is 6 to 10 seconds, and then poured. Such portland cement grout has the following problems.

(a) Due to insufficient early strength and quick hardening properties, it cannot be used in locations where equipment cannot be shut down for long periods of time, or in public facilities with limited downtime such as roads and tracks.

(b) Portland cement-based grout is formulated with an expanding agent to cause expansion at a relatively early stage of water use, up to about 7 days of age, and to reduce the amount of long-term drying shrinkage.1. This is intended to compensate for the volume reduction of the body as much as possible, but if the amount of swelling agent used is at a level that does not cause excessive expansion, the amount of expansion will be insufficient and the cured body will be left in dry conditions for a long period of time. Then, it contracts and becomes smaller than its original volume.

In recent years, from the perspective of both cost reduction and construction cost reduction, there has been a demand for further improvements in the early strength and quick hardening properties of grout, so ultra-fast hardening cement is being used instead of Portland cement. The grout obtained in this case is called a fast-setting non-shrinking grout or a super fast-setting non-shrinking grout. However, such ultra-rapid hardening cement grout materials also have the following problems.

(b) Since it is common for grout to take a considerable amount of time from the time it is mixed until the end of injection, it is necessary to maintain enough fluidity to allow the grout to be used for a certain period of time (for example, 30 minutes) after it has been mixed. must be maintained. In ultra-fast-hardening cement-based grout materials, it is attempted to ensure the fluidity of the ultra-fast-hardening, non-shrinkable grout by adding a setting retarder, but the fluidity is not sufficient even at room temperature, and even more so when the construction temperature is 30°C. If the temperature exceeds ℃, the fluidity decreases significantly over time, making construction difficult. In this case, it is not preferable to increase the amount of kneading water or add water when the fluidity decreases, since this will have a negative effect on the non-shrinkage properties, strength, etc. of the grout.

Means for Solving the Problems As a result of repeated research in view of the current state of the technology as described above, the present inventor has found that an ultra-fast hardening cement grout material containing an inorganic binder and a specific additive has been developed to solve the problems of known materials. It has been found that the problem can be substantially eliminated or greatly reduced.

That is, the present invention provides the following ultra-fast hardening non-shrink grout material: [Portland cement 30-80 parts by weight Alumina cement 5-50 parts by weight Gypsum]
5 to 20 parts by weight Calcium hydroxide and/or calcium carbonate 1 to 20 parts by weight of inorganic binder 100 parts by weight, oxycarboxylic acid and/or its salts 0.01 to 2.0 parts by weight Zinc compound 0.001 -0.5 parts by weight Expanding agent 0.005-0.02 parts by weight Water reducing agent 0.01-2.0 parts by weight Super-fast hardening non-shrink grout made by blending 0.001-2.0 parts by weight of fluidizing agent Material. j Below, each component used in the present invention and its usage ratio will be explained.

As is well known, in a composition, each component influences each other and produces a synergistic effect, so it may not always be appropriate to clearly indicate the reason for limiting each component, but it is possible to do so. The reason for the limitation is also shown.

In the present invention, portland cement, alumina cement, gypsum and calcium hydroxide and/or calcium carbonate are used as the inorganic binder phase.

Examples of the Portland cement include ordinary Portland cement, early strength Portland cement, ultra early strength Portland cement, sulfate-resistant Borland cement, and white Portland cement, and one or more of these may be used.

As the gypsum, one or more types of gypsum such as trihydrate gypsum, α-type hemihydrate gypsum, β-type hemihydrate gypsum, ■-type dihydrate gypsum, and ■-type dihydrate gypsum are used.

The proportions of each component in 100 parts by weight (hereinafter simply referred to as parts) of the inorganic binder are: 30 to 80 parts of Portland cement, 5 to 50 parts of alumina cement, 5 to 20 parts of gypsum, calcium hydroxide and/or calcium carbonate. 1 to 20 parts. If the blending ratio of photoland cement and alumina cement is outside the above range, it becomes difficult to sufficiently develop early strength and quick hardening properties. If the blending ratio of gypsum is less than 5 parts, the early strength and quick hardening properties will not be sufficiently improved, whereas if it exceeds 20 parts, abnormal expansion will occur in the cured product after a long period of time. Sometimes.

If the amount of calcium hydroxide and/or calcium carbide is less than 1 part, the early strength and quick hardening properties will not be sufficiently improved (on the other hand, if the amount is 20 parts),
There is a tendency for the strength of the cured product to decrease after a long period of time.

In the present invention, the inorganic binder further contains a small amount of oxycarboxylic acid and/or its salt (at least one kind of zinc compound, at least one kind of swelling agent, at least one water reducing agent, and a small amount of fluidizing agent). Add one kind of both.

Oxycarboxylic acid and/or its salt and zinc compound are:
It exerts a synergistic effect to suppress the decline in the fluidity of the grout and extend its pot life. Examples of oxycarboxylic acids include malic acid, tartaric acid, gluconic acid, and citric acid, and examples of salts thereof include alkali metal salts and alkaline earth metal salts. Among these, gluconic acid, citric acid, alkali metal salts and alkaline earth metal salts thereof are more preferred. Examples of zinc compounds include zinc oxide, zinc chloride, zinc bromide, zinc sulfate, zinc nitrate, zinc hydrogen carbonate, zinc acetate, zinc formate, zinc phosphate, and the like. The blending ratio for 100 parts of the inorganic binder is 0.01 to 2 parts of oxycarboxylic acid and/or its salt and 0.001 to 0.5 parts of the zinc compound. If the amount of either of the two is less than the lower limit, the synergistic effect of the two in preventing a decrease in the fluidity of the grout cannot be fully exerted. If it exceeds the upper limit, no further improvement in fluidity will be achieved, but rather a decrease in the strength of the cured product will occur.

As the expansion material, it is preferable to use an oxidation expansion type expansion shrine that utilizes the oxidation expansion mechanism of metal powder such as aluminum powder or iron powder. Hydraulic expansion materials that utilize a hydration expansion mechanism, such as lime-based and calcium sulfoaluminate-based materials, are not preferred because they exhibit a peculiar phenomenon in expansion properties when mixed with the above-mentioned inorganic binder. As such an oxidation expansion type expansion system, JIS K 5906
Particle size (88
It is preferable to use aluminum powder containing 2% or less of the main component of a μm mesh sieve. The mixing ratio of the expansion material to 100 parts of the inorganic binder is 0.005 to 0.02 parts.

If the blending ratio is less than 0.005 parts, expansion will be insufficient, whereas if it exceeds 0.02 parts, excessive fat expansion will occur.

The water reducing agent that reduces the amount of water required to obtain a predetermined fluidity, increases the strength of the cured product, and reduces the amount of drying shrinkage is not particularly limited, and any known one can be used as is. For example, products whose main component is a salt of a formalin condensate of naphthalene sulfonic acid (trade names "Mighty 100" and "Mighty 150" manufactured by Kao Corporation),
Co., Ltd. (trade name "Pole Fine 51ON", etc.), highly condensed triazine compounds (Hozolith Bussan Co., Ltd. trade name "NL-1450", "NL-4000", etc.),
Alkylaryl sulfonate polymer (Dalex (
Specific examples include the trademark name "Darlex Super 20" manufactured by Co., Ltd.). The mixing ratio of the water reducing agent to 00 parts of inorganic bond control is 0.01 to 2.0 parts. If the mixing ratio is less than 0.01 parts, the water-reducing effect will not be sufficiently exhibited, and if it exceeds 2.0 parts, solid-liquid separation may occur during hardening of the grout.

In the present invention, a fluidizing agent is used to reduce the viscosity of the grout to prevent material separation and to improve the filling properties of the grout.

The fluidizing agent is not particularly limited, and the formalin condensate of casein, calcium caseinate, and melamine sulfonic acid (for example, "Melment" manufactured by Showa Denko K.K.)
etc.) can be used. Inorganic binder 1
The mixing ratio of the fluidizing agent to 0.00 parts is 0.01 to 2.00 parts.
It will be 0 copies. If the blending ratio is less than 0.01 part, the effect of improving fluidity will not be sufficient, and if it exceeds 2.0 parts, the amount of kneading water to obtain the required fluidity will increase.
At the same time, the viscosity increases and filling properties deteriorate.

The grout material of the present invention may contain fillers, fine aggregates, etc., if necessary.

Bulking agents are added for purposes such as improving long-term strength and reducing costs, and are materials that can react with calcium hydroxide or calcium carbonate in a cement hydration environment to produce calcium silicate compounds. use. Such materials include activated siliceous fine powders such as fly ash, silica fume, and granulated blast furnace slag.

The amount of filler used varies depending on the composition of the grout material, but is usually about 200 parts or less per 100 parts of the inorganic binder. If the amount of bulking agent is excessive, early strength tends to decrease.

The fine aggregate is used for the purpose of reducing drying shrinkage and cost reduction, and specific examples thereof include river sand, sea sand, mountain sand, silica sand, kansui stone, and crushed sand. The particle size of the fine aggregate is preferably 2.5 mm or less at maximum. The amount of fine bone used varies depending on the composition of the grout material, but
Usually, the amount is about 250 parts per 100 parts of the inorganic binder. If the amount of fine aggregate is excessive, fluidity will be reduced.

Effects of the Invention In the grout material of the present invention, by combining oxycarboxylic acid and a zinc compound with the inorganic binder,
The high flow properties and long pot life improve workability in construction using grout materials. In addition, in the hardened product obtained from the grout material of the present invention, drying shrinkage is compensated for by the expansion of ettringite that is generated several hours after the start of water use, so it is better than the known hardened grout based on pol) and land cement. The amount of drying shrinkage is considerably reduced. Furthermore, due to the expansion at the initial stage of hydration due to the presence of the expanding agent and the reduction of loss on drying due to the presence of the water reducing agent and the fluidizing agent, reduction in shrinkage amount is further suppressed and early strength is also improved.

Therefore, according to the present invention, an ultra-rapid hardening non-shrinkage grout material having excellent fluidity, workability and early strength can be obtained.

For reference, the ultra-fast hardening non-shrinkage grout material (I) according to the present invention, the known Portland cement grout system (
II) and the known ultra-fast hardening cement grout ta (I[
The various characteristics of I) are summarized as follows. In Table 1, each symbol has the following meaning.

○...Excellent △...Average ×...Poor Table 1 (I) (II) (I[I) Fluidity ○ ○ ○Pot life
○ ○ ×No shrinkage during initial hydration
○○ ○ Long-term no shrinkage ○ × ○Fast hardening
○ × ○ Early strength
○ × ○ Examples Examples and comparative examples are shown below to further clarify the characteristics of the present invention.

Examples 1 to 4 First, inorganic binders having the compositions shown in Table 2 below were prepared.

Table 2 Portland cement 50 parts Alumina cement 30 parts Gypsum
10 parts calcium hydroxide
10 parts Then, the obtained inorganic binder 10
The grouting material of the present invention was obtained by blending the other components of the invention in the proportions shown in Table 3 with respect to 0 parts.

In Table 3, each symbol has the following meaning.

(A1)...Gluconic acid (A2)...Tartaric acid (A3)...Citric acid (B1)...Zinc oxide (B2)...Zinc chloride (B3)...Zinc sulfate (C) ... Formalin condensate-based water reducing agent of naphthalene sulfonic acid, trade name "Mighty 100", manufactured by Kao Corporation, (D) ... Melamine sulfonic acid formalin condensate-based fluidizing agent, trade name "Melment", Made by Showa Denko K.K. (E)... Expanding agent, aluminum powder with a particle size of 50 μm or less To the thus obtained grout material of the present invention, sand and water were added in the proportions shown in Table 4, and after uniformly kneading, Setting time (4th
Table), the compressive strength after a predetermined period of time (Table 5), and the J140-t flow time after a certain period of time (Table 6) were investigated.

In addition, Tables 4, 5, and 6 include Comparative Examples 1 and 2.
The results are also shown when a commercially available Portland cement-based non-shrink grout phase and a super fast-hardening cement-based non-shrink grout material were used.

In Table 4, each symbol has the following meaning.

S/G...Sand/grout weight ratio W, /G...Water/grout weight ratio Table 4 S/G W/G Setting (time 2 minutes) Starting Final Example 1 1 0.19 1:20 1:
402 L5 0. L4 1:55
2:203 1 0.19 L:25
L:454 1.5 0.14
1:55 2:255 1 0, L9
1:30 1:456 1.5 0.14
2:00 2:30 Comparative Example 1 1 0.19 8:45 7:
402 1 0.18 0:45 1
:00 Table 5 Compressive strength (kgf/c soak) 3hr 6hr 1st 3rd 7th 28th Example 1' 320 374 489 482 '5
00 573B '326 378 470 4
92 501 5774 170 228 38B
390 411 417 Comparative Example Also, using the grout materials of Examples 1 to 6 and Comparative Examples 1 to 2, the grout materials were poured into a mold, kept for up to 7 days, and then removed from the mold, and placed at a temperature of 20°C. After curing and drying at a relative humidity of 60%, the swelling ratio was measured using the micrometer method described in the "Expansible Concrete Design and Construction Guidelines (Draft)" edited by the Japan Society of Civil Engineers, and the graph shown in Figure 1 was obtained.

From the results shown in Tables 4 to 6 and Figure 1, the grout material of the present invention has an appropriate pot life, fluidity,
It is clear that it has excellent quick hardening and early strength properties, and the amount of shrinkage after curing is extremely small.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the shrinkage rates of cured products obtained using the grout material of the present invention and the comparative grout material. (that's all)

Claims (1)

[Claims] (1) For 100 parts by weight of an inorganic binder consisting of 30 to 80 parts by weight of Portland cement, 5 to 50 parts by weight of alumina cement, 5 to 20 parts by weight of gypsum, 1 to 20 parts by weight of calcium hydroxide and/or calcium carbonate, oxycarboxylic acid and/or salts thereof 0.01 to 2.0 parts by weight Zinc compound 0.001 to 0.5 parts by weight Expanding agent 0.005 to 0.02 parts by weight Water reducing agent 0.01 to 2.0 parts by weight Glidizer A super fast hardening non-shrinkage grout material containing 0.001 to 2.0 parts by weight.