JP3125316B2 - Temperature buffer type quick-setting composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature-buffer type quick-setting composition, and more particularly to a quick-setting composition using metallurgical slag containing calcium aluminate as a main component, and which can be used even when the working temperature changes. The present invention relates to a temperature-buffer type quick-setting composition which can ensure the same pot life and can obtain a high-strength cured product with excellent setting properties and workability.

[0002]

2. Description of the Related Art Emergency repair of roads, prevention of collapse of water stop walls,
Rapid hardening materials are required for water stoppage work, repair work for roads, structures, and structures, and for secondary product factories and the like where it is necessary to increase the formwork rotation rate.

[0003] The required properties of the quick-hardening materials used in the above-mentioned various fields are, of course, that they need to be hardened at an early stage after kneading, but that they are more likely to penetrate into cracks to be repaired and voids in the formation. It is an essential condition that it is easy to pour into the mold. That is, the kneaded material is required to maintain a predetermined fluidity for obtaining good workability until the end of the casting operation.
Furthermore, since these materials are generally used in large quantities because they are construction materials, it is also an important condition that the raw materials are inexpensive.

Heretofore, as such a quick-setting material, a cement obtained by adding a setting accelerator such as sodium carbonate, calcium chloride or water glass to portland cement or mixed cement, or a quick-setting cement such as alumina cement or jet cement has been used. Used.

However, among the above-mentioned conventional materials, quick-setting materials obtained by adding a setting accelerator to portland cement or mixed cement have low early strength development after kneading, and are generally used in places where high strength is required. It is difficult to do. In addition, some of the additives may elute a water-soluble substance during application or after curing, which may cause pollution.

On the other hand, fast-setting cements such as alumina cement and jet cement can be fired at 1350-1450 ° C.
High temperature and long time, material cost,
It is very expensive in terms of energy costs. For this reason, these quick-setting cements are expensive, so their use is limited to special works or when urgency is required, and the use range is limited. In particular, jet cement has the disadvantage that the fluidity is lost immediately after kneading, and the time required for maintaining the fluidity required for the work after kneading is short. Even if the pot life is extended by using a setting retarder in order to solve this drawback, a sufficient improvement effect cannot be obtained, and the workability is not always good. In addition to this kind of fast-setting cement, other than Portland cement or mixed cement, calcium aluminate calcined products are also commercially available, but these are also calcined in a dedicated firing furnace, so they will not be very expensive Not get.

As a result of repeated studies to solve the conventional problems as described above, the present inventors have found that when aluminum is used in the deoxidizing step of the stainless steel refining process, a large amount of aluminum is produced as a by-product. It has been found that metallurgical slag containing calcium aluminate as a main component has effective properties as a raw material of a quick-hardening composition, and a rapid-hardening composition containing this metallurgical slag was filed earlier by the present applicant ( 1962
60749, JP-A-63-277542).

[0008] These rapid-curing compositions comprise 12CaO · 7
The quick-hardening component obtained by mixing and pulverizing a metallurgical slag mainly composed of Al ₂ O ₃ , type II anhydrous gypsum, and a setting modifier (delay adjusting agent) is used in combination with ordinary Portland cement or mixed cement to improve the quick-setting property. What you get.

These quick-setting compositions have excellent properties such as good fluidity within a predetermined time (pot life) after kneading, and remarkably good strength development after the pot life. From, it is used in many fields.

[0010]

However, these quick-curing compositions have the following problems which need to be solved.

When the amount of the fast-setting component (metallurgical slag, type II anhydrous gypsum and setting modifier) to be added to the cement is small (for example, 20% or less), and the operating temperature is 10 ° C.
In the following cases, the strength development is extremely poor.

The addition amount of the setting regulator for obtaining the same pot life varies greatly depending on the use temperature, and it is difficult to adjust the addition amount.

Since metallurgical slag is a by-product generated from the steelmaking refining process, its chemical components fluctuate. However, depending on the chemical components, the rapid-curing composition differs in strength-developing properties and the like, and sufficient characteristics cannot be obtained. There are cases. For example, Ca
The quick-curing composition using a metallurgical slag having an O / Al ₂ O ₃ ratio of 1.3 or less has good short-term strength development of 3 hours of material age, but after 1 day of material age, 3 days of material age and 7 days of age. The increase in the strength of the sunshine age is extremely poor.

The present invention solves the above-mentioned conventional problems, and can obtain good strength development even when the components of the metallurgical slag are changed. It is an object of the present invention to provide a temperature-buffer type quick-setting composition that is easy and inexpensive.

[0015]

According to the first aspect of the present invention, there is provided a temperature-buffer type quick-setting composition, comprising a cement component comprising Portland cement and / or a mixed cement, and 2 to 50% by weight of the cement component. 0.1 to 5% by weight based on the total weight of the quick-setting component, the cement component and the quick-setting component
A fast-setting composition comprising a coagulation control agent, wherein the fast-setting component is 40 to 95% by weight of a fine metallurgical slag containing calcium aluminate as a main component and a type II anhydrous gypsum 5 to 5%. 6
0 to 1% by weight of a mixture of 1 to 10% by weight of alkali carbonate and 1 to 10% by weight of one or more selected from the group consisting of sodium aluminate, potassium aluminate and aluminum sulfate And the setting modifier comprises an organic acid-based setting retarder and an alkali sulfate.

[0016] Temperature buffered rapid hardening composition according to claim 2, A
Fine metallurgical slag containing calcium luminate as a main component is characterized in that when aluminum is used in the deoxidation step of the stainless steel refining process, the main component is calcium aluminate generated as a by-product. .

The type II anhydrous gypsum used in the present invention is a by-product gypsum by-product in a hydrofluoric acid production process, a natural gypsum (anhydrite,
Gypsum) or 650-8 as needed.
If calcined at 50 ° C. to form type II anhydrous gypsum,
Both can be used.

[0018] The quick-setting component of the quick-setting composition of the present invention is a fine metallurgical slag containing calcium aluminate as a main component.
(Hereinafter, simply referred to as "metallurgical slag" or "metallurgical slag.")
In a mixture consisting of 40 to 95% by weight and 5 to 60% by weight of anhydrous type II gypsum, 1 to 10% by weight of alkali carbonate is selected from the group consisting of sodium aluminate, potassium aluminate and aluminum sulfate. One or more kinds are added by 1 to 10% by weight.

Here, by mixing and pulverizing the fine metallurgical slag and the type II anhydrous gypsum, the amount of expansion of the cured product in water can be reduced.
If it is less than 95%, the strength developability is insufficient. If it exceeds 95% by weight, the long-term strength developability is poor. In addition, type II anhydrous gypsum is 5% by weight.
When it is less than 60%, the long-term strength developability is poor. When it exceeds 60% by weight, the obtained cured product may be swelled and broken.

When the addition amount of the alkali carbonate is less than 1% by weight based on the total amount of the metallurgical slag and the type II anhydrous gypsum,
The strength developability at low temperature with a small amount of fast-curing component used, for example, the strength developability at a use temperature of 10 ° C. or less with a fast-curing component usage of 20% by weight or less is a characteristic of the present invention. The use of ordinary Portland cement of different brands may significantly reduce the strength development. Among the chemical components of metallurgical slag, CaO
When the metallurgical slag having a / Al ₂ O ₃ ratio of 1.30 or less is used, the strength increase of the obtained cured product after one day of material age is extremely poor. Meanwhile, no amount significant difference in the addition effect more than 10% by weight of alkali carbonate, the occurrence of efflorescence les Ssensu on leading to rise in material costs and concern not preferable. Therefore, the addition amount of the alkali carbonate is set to 1 to 10% by weight. In addition, as alkali carbonate,
Sodium carbonate, potassium carbonate and the like can be used.

The addition amount of one or more selected from the group consisting of sodium aluminate, potassium aluminate and aluminum sulfate is 1% by weight based on the total amount of metallurgical slag and type II anhydrous gypsum. If the amount is less than 20% by weight or more than 20% by weight, it becomes impossible to exhibit the temperature buffering action characteristic of the present invention. That is, when the above-mentioned alkali carbonate is used in combination with sodium aluminate, potassium aluminate and / or aluminum sulfate, the ratio is alkali carbonate: (sodium aluminate, potassium aluminate and / or (Aluminum sulfate) = 2: 1
A range of １ ： 1: 2 (weight ratio) is preferred. For example, if this ratio exceeds the above range on the side where the amount of alkali carbonate is large, 5
At 20 ° C. the setting is faster and at 20 ° C. the setting is delayed.
Conversely, when the amount of alkali carbonate exceeds the above-mentioned range on the side where the amount of alkali carbonate is small, the setting is extremely fast, and it becomes difficult to adjust even if an appropriate amount of a setting retarder described later is used.

The quick-hardening component was prepared by converting metallurgical slag to a Blaine value of 4000.
To 8000 cm ² / g, and type II anhydrous gypsum is pulverized to a Blaine value of 4000 to 8000 cm ² / g, and these are added and mixed with alkali carbonate and the like, and further pulverized as necessary. Metallurgical slag and the like are mixed without being pulverized in advance, and a Blaine value of 4000 to 8000 cm ²
/ G. Here, if the Blaine value of the metallurgical slag used is less than 4000 cm ² / g, the strength development becomes poor, and if it exceeds 8000 cm ² / g, the pulverization cost rises. On the other hand, the Blaine value of type II anhydrous gypsum is 400
If it is less than 0 cm ² / g, the strength development properties are poor, and when the obtained cured product is immersed in water, the cured product may expand abnormally. On the other hand, if it exceeds 8000 cm ² / g, the pulverization cost rises. Therefore, it is preferable to use metallurgical slag and type II anhydrous gypsum that have been previously ground to a Blaine value of 4000 to 8000 cm ² / g.

In the present invention, among the components added as a setting regulator, examples of the organic acid-based setting retarder include oxycarboxylic acids and salts thereof. Specifically, oxycarboxylic acids such as tartaric acid, citric acid, malic acid, and gluconic acid, and sodium salts and calcium salts thereof such as
Species or two or more species. As alkali sulfate,
Examples include sodium sulfate and potassium sulfate.

The setting modifier is preferably prepared by mixing 0.25 to 7 parts by weight of alkali sulfate with respect to 1 part by weight of the organic acid-based setting retarder. Here, the ratio of alkali sulfate is 0.1.
If it is less than 25 parts by weight, the initial strength expression is reduced, and if it is more than 7 parts by weight, the retarding effect is significantly reduced. In the present invention, in particular, the setting modifier is tartaric acid: citric acid or sodium citrate: sodium sulfate = 1: 1: 2-2:
The ratio is preferably 1: 2 (weight ratio).

In the present invention, the addition amount of the setting modifier is
0.1 to the total weight of the cement component and the quick-setting component
5% by weight. If the amount of the setting modifier is less than 0.1% by weight, the retarding effect cannot be expected, and if it exceeds 5% by weight, it is over-delayed and is out of the range of use as a quick-setting composition.

Such a setting modifier may be used by mixing the above-mentioned alkali carbonate with sodium aluminate, potassium aluminate and / or aluminum sulfate and dissolving it in kneading water at the time of construction. It may be used by dry-mixing with fast-hardening components such as metallurgical slag and type II anhydrous gypsum.

In the conventional fast-curing composition, however, there is a problem in the work that the amount of the setting regulator required to secure the pot life differs significantly depending on the working temperature. For example, the addition amount of the setting agent for obtaining a pot life of about 30 minutes is 2 hours for a conventional setting agent of oxycarboxylic acid: alkali carbonate = 1: 4 (weight ratio).
0.20 to 0.25% by weight at 0 ° C, 0.7 to 0.2% at 5 ° C
1.0% by weight is required, 20 ° C and 5 ° C
And the amount of addition was significantly different. On the other hand, in the present invention, when the working temperature is about 20 ° C., the addition amount of the setting regulator is about 0.5% by weight. In addition, the difference in the amount of addition due to the temperature difference was very small, and the strength development was good even when the fast-hardening component was about 20% by weight and the application temperature was about 5 ° C.

The temperature-buffer type quick-setting composition of the present invention can be easily prepared by adding and mixing predetermined amounts of a cement component, a quick-setting component and a setting modifier, and has a kneading water amount of 30 to 100.
By kneading at a percentage by weight, it is possible to obtain a high-strength cured product with excellent setting properties and workability.
When using the temperature-buffered quick-setting composition of the present invention, dry sand, fly ash, re-emulsified synthetic powder resin, or the like may be added as other materials.

[0029]

EXAMPLES The effects of the present invention will be described more specifically with reference to examples and comparative examples.

[0030] Examples 1-10, Comparative Examples 1 and 2 metallurgical slags (Blaine value 1000 cm ² / g) and type II anhydrous gypsum (hydrofluoric acid gypsum) (Blaine value 2000 cm ² /
g) in a ratio of 65:35 (weight ratio), the amount of the additives shown in Table 1 was added to the mixture, and the mixture was mixed and pulverized.
0 cm ² / g of fast-curing components AF were prepared.

[0031]

[Table 1]

This quick-setting component is added to ordinary Portland cement in the ratio shown in Table 3, and the setting modifier (external addition) in the amount shown in Table 3 with respect to the total of this cement and the quick-setting component
(In Examples 9 and 10, 2% by weight of re-emulsified synthetic powder resin and 5% by weight of silica sand were further added), and the amount of water was 50% by weight (based on the total amount of cement and quick-setting component). Was prepared.

The working temperature, pot life and compressive strength of the obtained cement milk were measured, and the results are shown in Table 3.

The metallurgical slag used in each of the examples was a metallurgical slag N by-product having the composition shown in Table 2 below, which was by-produced during stainless steelmaking.
o. It is one of 1-3. As shown in Table 2 by X-ray diffraction, these are mainly composed of C ₁₂ A ₇ , MgO,
It has been confirmed that it contains C ₃ A.

The coagulation modifier internally added and the coagulation modifier externally added in the quick-hardening component F are tartaric acid: sodium citrate: sodium sulfate = 2: 1: 2 (weight ratio). Therefore, in each mixing ratio, the setting modifier is the sum of the externally added amount and the tartaric acid content internally added in the quick-setting component.

[0036]

[Table 2]

[0037]

[Table 3]

From Table 3, it can be seen that the temperature-buffer type quick-setting composition of the present invention exhibits sufficient strength even when a small amount of the quick-setting component is added, and has the same curing even when the working temperature is changed. It is clear that time can be gained.

[0039]

As described above in detail, according to the temperature buffering type quick-setting composition of the present invention, stable and good setting properties and workability can be secured at a wide range of working temperatures. Therefore, there is no need to change the composition due to seasonal changes or the like, and one composition can be applied to all seasons and regions. Moreover, sufficient strength development can be obtained with a small amount of the fast-hardening component added, and desired characteristics can be easily adjusted without being affected by the components of the metallurgical slag used. Therefore, the rapid-curing composition of the present invention does not need to be subjected to preliminary tests and the like, can be used easily and effectively, and is capable of obtaining a high-strength solidified body.

In addition, the rapid-curing composition of the present invention is a by-product of the steelmaking and refining process, and is provided at a low cost because metallurgical slag, which has been mostly dumped in landfills as industrial waste, is effectively used. It is effective in reducing processing costs, saving resources and energy. The temperature buffering type quick-setting composition of the present invention is extremely useful industrially, particularly as a premix material.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C04B 22:10 22:14 24:04) 103: 14 103: 22 (72) Inventor Hisajun Tanaka 1 Kitabukurocho, Omiya City, Saitama Prefecture 297-chome, Mitsubishi Materials Corporation Cement Research Institute (56) References JP-A-63-277542 (JP, A) JP-A-3-150249 (JP, A) JP-A-2-302351 (JP, A) 52-121632 (JP, A) WO 91/19687 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 28/02-28/08 C04B 18/14 C04B 22 / 08 C04B 22/10 C04B 22/14 C04B 24/04 C04B 18:14 C04B 22:08 C04B 22:10 C04B 22:14 C04B 22:04

Claims (2)

(57) [Claims] 1. A cement component comprising Portland cement and / or a mixed cement, a rapidly hardening component of 2 to 50% by weight based on the cement component, and 0 to a total weight of the cement component and the fast hardening component. 1. A temperature-buffer type quick-setting composition containing 1 to 5% by weight of a setting modifier, wherein the quick-setting component is 40 to 95% by weight of fine metallurgical slag containing calcium aluminate as a main component and type II anhydrous gypsum. In a mixture of 5 to 60% by weight, alkali carbonate is 1 to 10% by weight, and one or two or more kinds selected from the group consisting of sodium aluminate, potassium aluminate and aluminum sulfate are 1 to 10% by weight. %, And wherein the setting modifier comprises an organic acid-based setting retarder and an alkali sulfate. 2. The composition according to claim 1, wherein the fine metallurgical slag is mainly composed of calcium aluminate produced as a by-product when aluminum is used in a deoxidizing step of a stainless steel refining process. .