JP2004292307A - Hydraulic composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic composition from which mortar or concrete having good flowability or strength development can be produced although an inorganic powder such as a blast furnace slag powder having a small Blaine specific surface area (≤5,000 cm<SP>2</SP>/g) is used in the composition. <P>SOLUTION: The hydraulic composition contains a pulverized material of a fired material having a hydraulic modulus (H.M.) of 1.8-2.3 , a silica modulus (S.M.) of 1.3-2.3 and an iron modulus(I.M.) of 1.3-1.8, gypsum, and at least one inorganic powder selected from a blast furnace slag powder, fly ash, a limestone powder, and a silica stone powder. The fired material can be produced by using at lest one selected from industrial waste materials, municipal waste materials and soil generated by construction as a raw material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a hydraulic composition capable of producing mortar and concrete excellent in fluidity and strength.

Mortar and concrete using blast furnace cement obtained by blending blast furnace slag powder with Portland cement clinker and gypsum are more effective in suppressing alkali-aggregate reaction and sulfate resistance than mortar and concrete using ordinary Portland cement. It has the advantage of being excellent and having high long-term strength. However, mortar and concrete using blast furnace cement have a disadvantage that the initial strength is inferior to mortar and concrete using ordinary Portland cement. Therefore, the Blaine specific surface area of 6000 cm ² / g or more, in particular by using a large blast furnace slag powder 8000 cm ² / g or more fineness, attempts to improve the initial strength of mortar and concrete (for example, Patent Document 1).

JP-A-61-242942

However, in Patent Document 1, it is necessary to pulverize the blast furnace slag to have a Blaine specific surface area of 6000 cm ² / g or more, and there is a problem that the pulverization takes time.
In addition, by using a blast furnace slag powder having a high degree of fineness, the initial strength of mortar and concrete is improved, but the subsequent strength does not increase, and there is a problem that sufficient long-term strength may not be obtained. .
Further, since blast furnace slag powder having a high degree of fineness is used, there is a problem that the fluidity of mortar and concrete is reduced.

The present invention has been made in view of the problems and findings of the prior art described above, and an object thereof is to provide a hydraulic composition containing an inorganic powder such as a blast furnace slag powder having a small Blaine specific surface area (5000 cm ² / g or less). Even so, an object of the present invention is to provide a hydraulic composition capable of producing mortar and concrete having good fluidity and strength.

The present inventors have produced mortars and concretes having good fluidity and strength, even with hydraulic compositions containing inorganic powder such as blast furnace slag powder having a small Blaine specific surface area (5000 cm ² / g or less). As a result of diligent research on hydraulic compositions that can be made, the above problems can be solved by combining a pulverized product of a fired product having a specific hydraulic modulus, a silicic acid content and an iron content with an admixture such as gypsum and blast furnace slag powder. Can be solved, and the present invention has been completed.

That is, the present invention provides a pulverized product of a calcined product having a hydraulic modulus (HM) of 1.8 to 2.3, a silicic acid ratio (SM) of 1.3 to 2.3, and an iron ratio (IM) of 1.3 to 2.8, gypsum, and a blast furnace. A hydraulic composition comprising one or more inorganic powders selected from slag powder, fly ash, limestone powder, and silica stone powder (claim 1). Hydraulic compositions having such a composition can be used for mortars and concretes having good fluidity and strength while using inorganic powders such as blast furnace slag powder having a small Blaine specific surface area (5000 cm ² / g or less). Can be manufactured.
The fired product can be a fired product manufactured using at least one material selected from industrial waste, general waste, and soil generated from construction (claim 2). By using one or more materials selected from industrial waste, general waste and construction waste soil as the raw material of the fired product, it is possible to promote effective use of the waste.

In the present invention, the ratio of the gypsum hemihydrate to the total amount of the gypsum dihydrate and the gypsum hemihydrate in the hydraulic composition is preferably 30% by mass or more in terms of SO ₃ (claim 3). By increasing the proportion of hemihydrate gypsum, it is possible to further improve the fluidity and also to reduce the heat of hydration of the hydraulic composition.
In the present invention, the ratio of SO _{3 in} the gypsum dihydrate and hemihydrate gypsum to the total SO ₃ in the hydraulic composition is preferably 40% by mass or more (claim 4). By increasing the ratio of SO ₃ in dihydrate gypsum and hemihydrate gypsum to the total SO ₃ in the hydraulic composition, it is possible to further improve the fluidity and reduce the heat of hydration of the hydraulic composition. You can also.

In the hydraulic composition of the present invention, it is possible to produce mortar and concrete having good fluidity and strength while using inorganic powder such as blast furnace slag powder having a small Blaine specific surface area (5000 cm ² / g or less). Can be.
Further, in the hydraulic composition of the present invention, one or more kinds selected from industrial waste, general waste and construction waste soil can be used as a raw material, which can contribute to promotion of effective use of waste. it can.

Hereinafter, the present invention will be described in detail.
The calcined product used in the present invention has a hydraulic modulus (HM) of 1.8 to 2.3, a silicic acid ratio (SM) of 1.3 to 2.3, and an iron ratio (IM) of 1.3 to 2.8.
When the hydraulic hardness (HM) of the calcined product decreases, 3CaO.Al ₂ O ₃ (hereinafter abbreviated as C ₃ A) and 4CaO.Al ₂ O ₃ .Fe ₂ O ₃ (hereinafter C _{4 A)} (Abbreviated as AF) content tends to increase, and the fluidity of mortar and concrete tends to decrease. Further, it becomes difficult to fire the fired product. On the other hand, when the hydraulic modulus (HM) increases, the initial strength of the mortar or concrete increases, but the elongation of the long-term strength tends to be slow. Therefore, the hydraulic hardness (HM) is preferably 1.8 to 2.3, and more preferably 2.0 to 2.2.
When the silicic acid ratio (SM) of the calcined product decreases, the content of C ₃ A and C ₄ AF in the calcined product increases, and the fluidity of mortar and concrete tends to decrease. Further, it becomes difficult to fire the fired product. On the other hand, when the silicic acid ratio (SM) is large, it is preferable in terms of fluidity of mortar and concrete, but the content of C ₃ A and C ₄ AF is small, and it becomes difficult to fire the fired product. Therefore, the silicic acid ratio (SM) is preferably 1.3 to 2.3.
When the iron ratio (IM) of the fired product is small, it is preferable in terms of fluidity of mortar and concrete, but the crushability of the fired product is reduced. On the other hand, when the iron ratio (IM) increases, the content of C ₃ A in the fired product increases, and the fluidity of mortar and concrete tends to decrease. Therefore, the iron ratio (IM) is preferably 1.3 to 2.8.

As a raw material of the burned material, generally of Portland cement clinker raw material, i.e. limestone, quicklime, CaO raw material such as slaked lime, silica, SiO ₂ raw clay such as Al ₂ O ₃ raw material such as clay, Tetsukasu, such as iron cake Fe ₂ O ₃ raw materials can be used.
In the present invention, as the raw material of the fired product, in addition to the raw material, at least one selected from industrial waste, general waste, and construction soil can be used. It is preferable to use one or more materials selected from industrial waste, general waste, and construction waste soil as a raw material of the fired product because effective use of the waste can be promoted. Here, as the industrial waste, for example, raw corn sludge, various sludges (for example, sewage sludge, purified water sludge, construction sludge, iron making sludge, etc.), construction waste material, concrete waste material, boring waste soil, various incineration ash, molding sand, Examples include rock wool, waste glass, blast furnace secondary ash, and the like. Examples of the general waste include sewage sludge dry powder, municipal waste incineration ash, shells, and the like. Examples of the soil generated from construction include soil and residual soil generated from construction sites and construction sites, and waste soil.

The above raw materials are mixed so as to have predetermined HM, SM, and IM, and are preferably fired at 1200 to 1550 ° C. to produce a fired product. A more preferred firing temperature is 1350 to 1450 ° C.
The method of mixing the respective raw materials is not particularly limited, and may be performed using a conventional apparatus or the like.
The apparatus used for firing is not particularly limited, and for example, a rotary kiln or the like can be used. When firing in a rotary kiln, a fuel substitute waste, for example, waste oil, waste tire, waste plastic, or the like can be used.
In the fired product used in the present invention, the amount of free lime is preferably 0.5 to 1.0% by mass from the viewpoint of improving the strength developing property of mortar and concrete, particularly the initial strength developing property.

As gypsum, dihydrate gypsum, α-type or β-type hemihydrate gypsum, anhydrous gypsum and the like can be used alone or in combination of two or more.
In the present invention, the ratio of gypsum hemihydrate to the total amount of gypsum dihydrate and hemihydrate gypsum in the hydraulic composition is preferably 30% by mass or more in terms of SO ₃ . By increasing the ratio of gypsum hemihydrate to the total amount of gypsum dihydrate and gypsum hemihydrate in the hydraulic composition to 30% by mass or more in terms of SO ₃ , the fluidity of mortar and concrete is further improved, and the hydraulic composition The heat of hydration of the product can be reduced. A more preferable ratio of the gypsum hemihydrate to the total amount of the gypsum dihydrate and the gypsum hemihydrate is 60% by mass or more, particularly preferably 70% by mass or more in terms of SO ₃ .

Further, in the present invention, the ratio of SO ₃ in gypsum dihydrate and hemihydrate gypsum to all SO ₃ in the hydraulic composition is preferably 40% by mass or more. By increasing the ratio of SO _{3 in} the dihydrate gypsum and hemihydrate gypsum to the total SO ₃ in the hydraulic composition to 40% by mass or more, it is possible to further improve the fluidity of the mortar or concrete and to increase the water content of the hydraulic composition. Reduction of sum heat can be achieved. The more preferable ratio of SO ₃ in gypsum dihydrate and hemihydrate gypsum to the total SO ₃ in the hydraulic composition is 50 to 95% by mass, particularly preferably 60 to 90% by mass.
The amount of gypsum dihydrate / hemihydrate gypsum can be determined by thermal analysis (thermogravimetry or the like) using a sample container described in JP-A-6-242035. Further, the quantification of the total amount of SO ₃ in the hydraulic composition can be performed by chemical analysis.

Gypsum amount of hydraulic composition is from mortar or concrete fluidity and strength development, etc., with respect to the pulverized product 100 parts by weight of the baked product, preferably 1 to 5 parts by weight converted to SO _3, More preferably, it is 2 to 3.5 parts by mass.

The hydraulic composition of the present invention contains one or more inorganic powders selected from blast furnace slag powder, fly ash, limestone powder, and silica stone powder. As the inorganic powder, blast furnace slag powder, or a combination of blast furnace slag powder and limestone powder is used because of the fluidity and strength development of mortar and concrete, as well as the effect of suppressing alkali-aggregate reaction and sulfate resistance. Is preferred.
In the present invention, the amount of the inorganic powder in the hydraulic composition varies depending on the type of the inorganic powder. For example, if the blast furnace slag powder, the fluidity and strength development of mortar and concrete, furthermore, the effect of suppressing alkali-aggregate reaction, sulfate resistance, etc. It is preferably from 150 to 150 parts by mass, more preferably from 20 to 100 parts by mass. In the case of fly ash, limestone powder or silica stone powder, the amount is preferably from 10 to 100 parts by mass, more preferably from 20 to 80 parts by mass, based on 100 parts by mass of the fired material. When blast furnace slag powder and limestone powder are used in combination, the blast furnace slag powder is used in an amount of 10 to 150 parts by mass with respect to 100 parts by mass of the baked material due to the fluidity and strength development of mortar and concrete. Preferably, the limestone powder is used in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the pulverized fired product.

The method for producing the hydraulic composition of the present invention will be described.
As a method for producing a hydraulic composition, for example,
1) a method of simultaneously pulverizing the calcined product and gypsum, and mixing the pulverized product with one or more inorganic powders selected from blast furnace slag powder, fly ash, limestone powder, and silica powder;
2) a method of pulverizing the calcined product, mixing the gypsum with one or more inorganic powders selected from gypsum, blast furnace slag powder, fly ash, limestone powder, and silica stone powder;
3) a method of simultaneously pulverizing one or more inorganic powders selected from a calcined product, gypsum, blast furnace slag powder, fly ash, limestone powder, and silica stone powder,
And the like.

In the case of the above 1), the calcined product and the gypsum are preferably pulverized to a Blaine specific surface area of 2500 to 4500 cm ² / g, more preferably to 3000 to 4500 cm ² / g. Further, it is preferable as the inorganic powder to use a Blaine specific surface area 2500~5000cm ² / g, and more preferred to use those 3000~4500cm ² / g.
In the case of the above 2), the fired product is preferably pulverized to a Blaine specific surface area of 2500 to 4500 cm ² / g, more preferably to 3000 to 4500 cm ² / g. Further, it is preferable as a plaster and an inorganic powder to use a Blaine specific surface area 2500~5000cm ² / g, and more preferred to use those 3000~4500cm ² / g.
In the present invention, the specific surface area of the hydraulic composition is preferably 2500 to 4500 cm ² / g, and more preferably 3000 to 4500 cm ² / g, from the viewpoint of fluidity and strength development of mortar and concrete. Is more preferred.

The hydraulic composition of the present invention is used in a paste, mortar or concrete state. As the water reducing agent, a lignin-based, naphthalenesulfonic acid-based, melamine-based, or polycarboxylic acid-based water reducing agent (including an AE water reducing agent, a high-performance water reducing agent, and a high-performance AE water reducing agent) can be used.
When used in the form of mortar or concrete, fine aggregates and coarse aggregates usually used in the production of mortar and concrete, that is, river sand, land sand, crushed sand, river gravel, mountain gravel, crushed stone, etc. Can be used. In addition, molten slag produced by melting at least one of municipal garbage, municipal garbage incineration ash, and sewage sludge incineration ash, or blast furnace slag, steelmaking slag, copper slag, insulator waste, glass cullet, ceramic waste, clinker ash, waste brick In addition, waste such as concrete waste can be used for part or all of fine aggregate and coarse aggregate.
In addition, if necessary, an admixture such as an air entraining agent and an antifoaming agent may be used within a range that does not cause any trouble.

The method of kneading the paste, mortar or concrete is not particularly limited, and, for example, 1) a method in which each material is collectively charged into a mixer and kneaded for 1 minute or more, and 2) a material other than water is charged into the mixer. After kneading, it can be carried out by a method of adding water and kneading for 1 minute or more. The mixer used for kneading is not particularly limited, and may be kneaded with a conventional mixer such as a Hobart mixer, a pan-type mixer, and a twin-screw mixer.
The method for forming the paste, mortar, or concrete is not particularly limited, and for example, vibration molding or the like may be performed.
The curing conditions are not particularly limited, and for example, air curing, steam curing, or the like may be performed.

Hereinafter, the present invention will be described with reference to examples.
1. Manufacture of calcined products Using raw materials such as sewage sludge, construction waste soil, and general Portland cement clinker materials such as limestone, the hydraulic hardness (HM), silicate ratio (SM) and iron ratio ( IM). The prepared raw material was fired at 1400 to 1450 ° C. in a small rotary kiln to produce a fired product. At this time, waste oil and waste plastic were used as fuel in addition to general heavy oil. The chemical composition (% by mass) of the used sewage sludge and construction waste soil is as shown in Table 2.
The amount of free lime in each fired product was 0.6 to 1.0% by mass.

2. Preparation of crushed product of calcined product and gypsum (hereinafter abbreviated as crushed product) Exhausted dehydrated gypsum (manufactured by Sumitomo Metal Co., Ltd.) was heated at 140 ° C. to 100 parts by mass of each calcined product in Table 1. Gypsum hemihydrate was added so as to be 3.0 parts by mass in terms of SO ₃ , and was simultaneously pulverized with a batch-type ball mill so that the Blaine specific surface area became 3250 ± 50 cm ² / g to prepare a pulverized product.

3. Materials for mortar Materials other than the above pulverized materials are shown below.
1) Blast furnace slag powder; Blaine specific surface area 4000cm ² / g
2) Limestone powder; Blaine specific surface area 4230cm ² / g
3) Fine aggregate; standard sand specified in "JIS R 5201 (Physical test method for cement)"
4) Water; tap water
5) Water reducing agent: polycarboxylic acid-based high-performance AE water reducing agent (NMEB "Leobuild SP8N")

4. Production and evaluation of mortar The pulverized product and the blast furnace slag powder were mixed at a ratio shown in Table 3 to prepare a hydraulic composition. A mortar was prepared using the hydraulic composition, the fine aggregate, water and a water reducing agent, and the following measurement was performed.
1) Flow value The mortar immediately after kneading was put into a flow cone (upper diameter 5 cm, lower diameter 10 cm, height 15 cm), and the spread of the mortar when the flow cone was removed upward was measured to obtain a flow value. The mortar was mixed with a water / hydraulic composition (mass) ratio of 0.35, a fine aggregate / hydraulic composition (mass) ratio of 2.0, and a water reducing agent / hydraulic composition (mass) ratio of 0.0065. .
2) Compressive strength The compressive strength of mortar (3 days, 7 days and 28 days) was measured according to "JIS R 5201 (Physical test method of cement)". The mortar was mixed with a water / hydraulic composition (mass) ratio of 0.5 and a fine aggregate / hydraulic composition (mass) ratio of 3.0.
Table 3 shows the results.

  Table 3 shows that the mortar using the hydraulic composition of the present invention (Examples 1 to 8) has good fluidity and strength.

5. Preparation of crushed product of calcined product and gypsum (hereinafter abbreviated as crushed product) For 100 parts by mass of calcined product (No. 3) in Table 1, drained water gypsum (manufactured by Sumitomo Metal Co., Ltd.) The hemihydrate gypsum obtained by heating water gypsum at 140 ° C. was added in the amount shown in Table 4 and simultaneously pulverized so as to have a Blaine specific surface area of 3250 ± 50 cm ² / g by a batch type ball mill to prepare a pulverized product. did.

6. Production and evaluation of mortar 55 parts by mass of each pulverized material shown in Table 4, 45 parts by mass of the blast furnace slag powder and 5 parts by mass of the limestone powder were mixed to prepare a hydraulic composition. A mortar was prepared using the hydraulic composition, the fine aggregate, water and a water reducing agent, and the flow value and the compressive strength were measured in the same manner as in Example 1. The heat of hydration of the hydraulic composition was measured by the following method.
1) Heat of hydration Measured according to “JIS R 5201 (physical test method for cement)”.
Table 5 shows the results.

  Table 5 shows that the higher the ratio of gypsum hemihydrate to the total amount of gypsum dihydrate and gypsum hemihydrate, the higher the fluidity of the mortar and the lower the heat of hydration.

Claims (4)

  Hydraulic modulus (HM) is 1.8-2.3, silicic acid rate (SM) is 1.3-2.3, iron rate (IM) is 1.3-2.8, pulverized material, gypsum, blast furnace slag powder, fly ash, A hydraulic composition comprising one or more inorganic powders selected from limestone powder and silica stone powder.   The hydraulic composition according to claim 1, wherein the calcined product is a calcined product produced using at least one material selected from industrial waste, general waste, and construction soil as a raw material. _{3. The} hydraulic composition according to claim 1, wherein the ratio of gypsum hemihydrate to the total amount of gypsum dihydrate and hemihydrate gypsum in the hydraulic composition is 30% by mass or more in terms of SO _3. 4. Ratio of SO ₃ 2 dihydrate gypsum and hemihydrate gypsum to the total SO ₃ hydraulic composition is, hydraulic composition according to any one of claims 1 to 3 is 40 mass% or more.