Concrete composition and method for producing same
阅读说明：本技术 混凝土组合物及其制造方法 (Concrete composition and method for producing same ) 是由 松田拓 野口贵文 兼松学 于 2018-04-11 设计创作，主要内容包括：本发明的混凝土组合物含有：高炉渣；膨胀材料及水泥中的至少任一种；以及水；且所述水的单位水量为130kg/m<Sup>3</Sup>以下,所述水泥的含量相对于所述高炉渣为22质量％以下,坍流度值为40cm以上。(The concrete composition of the present invention comprises: blast furnace slag; at least any one of an expanding material and cement; and water; and the unit water amount of the water is 130kg/m 3 The cement content is 22 mass% or less with respect to the blast furnace slag, and the slump flow value is 40cm or more.)
1. A concrete composition characterized in that said concrete composition comprises: blast furnace slag; at least any one of an expanding material and cement; and water; and is
The unit water amount of the water is 130kg/m3In the following, the following description is given,
the cement content is 22 mass% or less relative to the blast furnace slag,
the slump flow value is more than 40 cm.
2. The concrete composition according to claim 1, wherein the slump flow value is 50cm or more.
3. The concrete composition according to any one of claims 1 to 2, wherein the water has a unit water amount of 100kg/m3The following.
4. A concrete composition according to any one of claims 1 to 3 wherein the content of the intumescent material is 3kg/m3The above.
5. A concrete composition according to any one of claims 1 to 4 wherein the content of the intumescent material is 5kg/m3The above.
6. The concrete composition according to any one of claims 1 to 5, further comprising ferronickel slag.
7. The concrete composition according to any one of claims 1 to 6, wherein the content of the cement is 0 mass% with respect to the blast furnace slag.
8. A concrete composition according to any one of claims 1 to 7 which further comprises limestone.
9. The concrete composition according to any one of claims 1 to 8, wherein the expanding material is a lime-based expanding material.
10. A method for producing a concrete composition, characterized in that the concrete composition contains: blast furnace slag; at least any one of an expanding material and cement; and water; and is
The sheet of waterThe water quantity is 130kg/m3In the following, the following description is given,
the cement content is 22 mass% or less relative to the blast furnace slag,
the slump flow value is more than 40 cm.
Technical Field
The present invention relates to a concrete composition and a method for producing the same.
Background
In buildings such as buildings, concrete obtained by hardening a concrete composition is widely used. Generally, the concrete composition comprises: the cement-based binder includes a binder for cement, a fine aggregate such as sand, a coarse aggregate such as stone, and water. The concrete composition can obtain a cured product of the concrete composition having desired properties (e.g., strength, fluidity, etc.) by changing the kind and amount of the substance contained therein.
The cement is generally produced by the following method. A composition called cement clinker is produced by calcining raw materials such as limestone and clay at high temperature. The cement clinker is pulverized and gypsum is added to obtain cement. It is considered that since carbon dioxide is generated at the stage of manufacturing the cement clinker, the cement imposes a burden on the environment. Therefore, the concrete composition has been proposed which suppresses the use of the cement and has a low environmental load (for example, refer to patent documents 1 to 2).
However, in the concrete compositions of these proposals, the water contents (unit water amount) were 160kg/m, respectively3～174kg/m3On the left and right sides, relatively much water is contained. It is known that shrinkage (self-shrinkage) generally occurs when the concrete composition is hardened. It is also known that the concrete composition shrinks (drying shrinkage) with evaporation of water or the like after it is cured. Therefore, when the concrete composition having a relatively large water content as in the proposed case is hardened, shrinkage occurs to cause chapping.
As the concrete composition having a small water content (unit water amount), it is proposed to reduce the unit water amount to 80kg/m3～85kg/m3Left and right of the concrete composition (see, for example, patent reference)Documents 3 to 4).
However, in these proposals, the concrete composition is poor in fluidity and therefore can be used only for special applications such as embankments. The concrete composition requires good fluidity from the viewpoint of use in various buildings.
Disclosure of Invention
[ problems to be solved by the invention ]
Therefore, a concrete composition which has a low environmental load, a cured product having strength equivalent to that of conventional concrete, and good fluidity has been desired.
The invention aims to provide a concrete composition which has low environmental load, has a cured product with the same strength as the conventional concrete and has good fluidity, and a manufacturing method thereof.
[ means for solving problems ]
As a method for solving the problem, the following is described. Namely:
< 1 > a concrete composition, characterized in that said concrete composition comprises: blast furnace slag; at least any one of an expanding material and cement; and water; and the unit water amount of the water is 130kg/m3The cement content is 22 mass% or less with respect to the blast furnace slag, and the slump flow value is 40cm or more.
< 2 > the concrete composition according to the above < 1 >, wherein the slump flow value is 50cm or more.
< 3 > the concrete composition according to any one of said < 1 > to < 2 >, wherein the unit water amount of said water is 100kg/m3The following.
< 4 > the concrete composition according to any one of said < 1 > to < 3 >, wherein the content of said expansive material is 3kg/m3The above.
< 5 > the concrete composition according to any one of said < 1 > to < 4 >, wherein the content of said expansive material is 5kg/m3The above.
< 6 > the concrete composition according to any one of said < 1 > to < 5 >, further comprising ferronickel slag.
< 7 > the concrete composition according to any one of the < 1 > to < 6 >, wherein the content of the cement is 0% by mass relative to the blast furnace slag.
< 8 > the concrete composition according to any one of said < 1 > to < 7 >, further comprising limestone.
< 9 > the concrete composition according to any one of said < 1 > to < 8 >, wherein said expanding material is a lime-based expanding material.
< 10 > a method for producing a concrete composition, characterized in that said concrete composition comprises: blast furnace slag; at least any one of an expanding material and cement; and water; and is
The unit water amount of the water is 130kg/m3In the following, the following description is given,
the cement content is 22 mass% or less relative to the blast furnace slag,
the slump flow value is more than 40 cm.
[ Effect of the invention ]
According to the present invention, a concrete composition which has a low environmental load, has a cured product having strength equivalent to that of conventional concrete, and has good fluidity, and a method for producing the same can be provided.
Detailed Description
(concrete composition)
The concrete composition of the present invention comprises: blast furnace slag; at least any one of an expanding material and cement; and water; further optionally containing other components.
< blast furnace slag >
The blast furnace slag is obtained by recovering components other than iron contained in iron ore together with limestone as a secondary raw material and ash in coke (by-product) in a step of producing pig iron from the iron ore. The blast furnace slag contains CaO and SiO2、Al2O3MgO, and the like.
The blast furnace slag is not particularly limited as long as it can be generally used in a concrete composition, and may be appropriately selected according to the purpose. Examples of the blast furnace slag include: blast furnace slag used in JIS R5211 "blast furnace cement", blast furnace slag conforming to JIS A6206 "blast furnace slag fine powder for concrete", and the like.
The fineness of the blast furnace slag is not particularly limited and may be appropriately selected according to the purpose, and is preferably 3,000cm213,000cm above g2Less than g, more preferably 3,000cm28,000cm above g2The ratio of the carbon atoms to the carbon atoms is less than g. If the fineness value is within the above range, the fluidity of the concrete composition and the strength of the cured product of the concrete composition can be improved.
The content of the blast furnace slag is not particularly limited and may be appropriately selected according to the purpose, and is preferably 200kg/m with respect to the entire concrete composition3～500kg/m3. If the blast furnace slag content is in the above range, the strength of the cured product of the concrete composition can be improved.
< intumescent Material >
The swelling material is a material which dissolves calcium ions when put in water. The expansion material is not particularly limited as long as it meets JIS a 6202 "expansion material for concrete" in japanese industrial standards, and may be appropriately selected according to the purpose. Examples of the expanding material include: mainly contains CaO and CaSO4The lime-based expanding material mainly contains CaO and C3A·CaSO4、CaSO4And an ettringite-based expanding material. These may be used alone or in combination of two or more. Among these, lime-based puffing containing calcium oxide is preferable from the viewpoint of reducing shrinkageAnd (4) swelling the material.
The expansion material is one of specific examples of a material for showing the performance of the binding material of the blast furnace slag.
The performance-imparting material of a binding material for blast furnace slag (hereinafter, sometimes simply referred to as "performance material") is a substance that imparts performance to the performance of the binding material for blast furnace slag.
The blast furnace slag cannot exhibit the binder property only by itself, but if the binder property-exhibiting material of the blast furnace slag acts on the blast furnace slag, the binder property can function. This is because the performance material and the silicon dioxide (SiO) contained in the blast furnace slag2) And alumina (Al)2O3) The reaction is carried out. The concrete composition is hardened by the binding material property exhibiting material containing the blast furnace slag.
As the binding material property exhibiting material of the blast furnace slag, an alkali-activated material is preferably used.
In the present invention, the alkali-activated material is a material in which an aqueous solution (or suspension) becomes alkaline when mixed with water. One of specific examples of the alkali-activated material is the swelling material.
The content of the expanding material is not particularly limited, and may be appropriately selected depending on the purpose, and is preferably 3kg/m in terms of reducing shrinkage3Above, more preferably 5kg/m3Above, more preferably 15kg/m3The above. Further, as the content of the expanding material, 200kg/m is preferable3The following.
< Cement >
The cement is not particularly limited as long as it is generally used in a concrete composition, and may be appropriately selected according to the purpose, and examples thereof include: portland cements such as ordinary, medium-heat, low-heat, early-strength, super-early-strength, and sulfate-resistant cements, mixed cements such as blast furnace cement, fly ash cement, and silica cement, super-rapid cements such as alumina cement and quick-setting cement, and kyanite-based cement. These may be used alone or in combination of two or more.
The content of the cement is 22 mass% or less, preferably 5 mass% or less, and more preferably 0 mass% with respect to the mass of the blast furnace slag (substantially not contained), from the viewpoint of reducing the burden on the environment.
< water >)
The water is not particularly limited and may be appropriately selected according to the purpose.
The unit water amount (content) of the water is 130kg/m3Below, preferably 110kg/m3Below, more preferably 100kg/m3Below, more preferably 85kg/m3The following. If the unit water amount is 130kg/m3Hereinafter, the shrinkage of the hardened material of the cement composition can be reduced.
Further, the unit amount of water is preferably 65kg/m in terms of fluidity3Above, more preferably 75kg/m3The above.
The ratio of the mass of water to the mass of the blast furnace slag (water/blast furnace slag ratio) is preferably 36 mass% or less. If the water/blast furnace slag ratio is 36% by mass or less, the fluidity can be improved.
In addition, if the water/blast furnace slag ratio is more than 36 mass%, proper fluidity cannot be obtained.
< other ingredients >
The other components are not particularly limited as long as they can be generally used in a concrete composition, and may be appropriately selected according to the purpose, and examples thereof include: silicon powder, fly ash, fine aggregate, coarse aggregate, mixing agent and the like.
Silica powder
The silicon powder is fine particles (the average particle size of the primary particles is about 0.1 to 1.0 μm) obtained by collecting dust from exhaust gas generated in a refining process of ferrosilicon, fused zirconia, metallic silicon, or the like. The silicon powder is amorphous SiO2The main component further contains alumina, iron oxide, calcium oxide, titanium oxide, and the like.
When the silica fume is mixed with the performance-imparting material for binding material of blast furnace slag, the silica fume reacts with calcium hydroxide (pozzolan reaction) generated upon hydration of the performance-imparting material for binding material of blast furnace slag, and functions to improve the strength of the hardened material of the concrete composition.
The content of the silicon powder is preferably 80kg/m3Above 130kg/m3The following. If the content of the silicon powder is within this numerical range, the fluidity of the cured product of the concrete composition can be improved.
Fly ash
The fly ash is an industrial waste generated in a coal-fired power plant. In the coal-fired power plant, finely pulverized coal is burned in a boiler to convert its energy into electricity. The coal turns into ash by this combustion, but ash particles in a molten state are suspended in the high-temperature combustion gas, become spherical fine particles as the temperature decreases at the boiler outlet, and are captured by the electric dust collector. The captured spherical fine particles are generally referred to as fly ash.
When the fly ash is mixed with the binding-material-performance-exhibiting material for blast furnace slag, the fly ash reacts with calcium hydroxide (pozzolan reaction) generated upon hydration of the binding-material-performance-exhibiting material for blast furnace slag, and acts to improve the strength of a hardened material of a concrete composition.
Fly ash contains a large amount of silicon dioxide (SiO)2) And alumina (Al)2O3) In addition to these, iron oxide, magnesium oxide, and calcium oxide are included.
Fly ash used in concrete compositions was specified in JIS to have 4 qualities (fly ash types I to IV). In the present invention, any quality can be used, and of these, I-type fly ash is preferable in terms of improvement of fluidity and strength of hardened material.
As the content of the fly ash, 100kg/m is preferable3Above 300kg/m3The following. If the content of the fly ash is within this numerical range, the fluidity of the concrete composition and the strength of the hardened material of the concrete composition can be improved.
Fine aggregate
The fine aggregate is not particularly limited as long as it can be generally used in a concrete composition, and may be appropriately selected according to the purpose, and may be a natural product or an artificial product. Specific examples of the fine aggregate include: nickel iron slag (FNS1.2A conforming to JIS a 5011-2, FNS 5A), copper slag (CUS 1.2 conforming to JIS a 5011-3), electric furnace oxidizing slag (N or H conforming to EFS1.2 of JIS a 5011-4), hard sandstone crushed sand, and the like. These may be used alone or in combination of two or more. Among these, nickel iron slag is preferable in terms of reduction of shrinkage.
Among the nickel slag, the nickel slag having the following characteristics is preferable in terms of reduction of shrinkage.
Water absorption of 1.50% or more.
When the water-saturated state is left in an environment at a temperature of approximately 20 ℃ and a relative humidity of approximately 95%, the water content is reduced to 0.50% or less.
The water absorption ratio is a ratio of a mass (g) of water in a state where the surface of the nickel iron slag is dried (surface-dried state) and the voids in the nickel iron slag are saturated with water to a mass (g) of the nickel iron slag in an absolutely dried state. The moisture content is a ratio of a total mass (g) of water contained in voids inside the nickel-iron slag and surface water (water adhering to the surface of the fine aggregate) to a mass (g) of the nickel-iron slag in an absolutely dry state. The water content is a value that varies depending on the dried state of the nickel iron slag.
Examples of the nickel-iron slag having the above characteristics include PAMCOSAND (registered trademark) manufactured by pacific metals corporation.
The content of the fine aggregate is preferably 900kg/m3Above 1,300kg/m3The following. If the content is within the numerical range, the fluidity and the strength of the cured product become good.
Coarse aggregate
The coarse aggregate is not particularly limited as long as it can be generally used in a concrete composition, and may be appropriately selected according to the purpose, and may be a natural product or an artificial product.
Examples of the natural coarse aggregate include: and coarse aggregates such as crushed stones 2015, crushed stones 2013, crushed stones 2010, crushed stones 1505, crushed stones 1305, and No. 5 or No. 6 of "crushed stones for roads" in JIS a 5005, and the like. Specific examples thereof include: hard sandstone crushed stones, andesite crushed stones, basalt crushed stones, quartz schist crushed stones, lime crushed stones and the like.
Examples of the synthetic coarse aggregate include: and a coarse aggregate of ferronickel slag aggregate (by-product in ferronickel production) which meets JIS a 5011-2. Specific examples thereof include: artificial corundum, sintered bauxite, and the like.
Among these, lime crushed stone is preferable from the viewpoint of reducing shrinkage.
The content of the coarse aggregate is preferably 500kg/m3Above 1,000kg/m3The following. If the content is within the numerical range, the fluidity and the strength of the cured product become good.
(mixture)
The admixture (hereinafter, also referred to as "chemical admixture") is not particularly limited as long as it can be generally used in a concrete composition, and may be appropriately selected according to the purpose. Specific examples of the admixture include: common polycarboxylic acid-based high-performance water reducing agents having a high water reducing rate, polyoxyalkylenealkyl ether-based defoaming agents, and the like.
The amount of the polycarboxylic acid-based high-performance water reducing agent to be added is appropriately adjusted depending on the concrete composition.
< Properties of concrete composition and cured product thereof >
The concrete composition of the present invention has the following physical properties.
Slump flow value
The slump flow value is a value representing the fluidity of the concrete composition. The slump flow value is measured according to JIS A1150 "slump flow test of concrete".
The slump flow value of the concrete composition of the present invention is 40cm or more, preferably 50cm or more in view of homogeneity and workability.
Compressive strength-
The compressive strength is measured according to JIS A1108 "compression test method for concrete". Samples used for the measurement of the compressive strength were 7 days and 28 days old (start of kneading of the concrete composition, time after adding water to the binder performance expressing material of the blast furnace slag).
Shrinkage strain (self-shrinkage strain, drying shrinkage strain) -
The self-contraction strain was measured by a method according to the methods of the self-contraction research council of the japan concrete institute and the super-fluid concrete research council of the japan concrete institute, the sealing was released at a age of 7 days, and the added value of the self-contraction strain and the drying contraction strain was measured in a dry environment. The measurement of the shrinkage strain was carried out until the age of the material was 28 days.
(method for producing concrete composition)
The method for producing the concrete composition of the present invention is not particularly limited as long as it is a general method for producing a concrete composition, and may be appropriately selected according to the purpose, and for example, the concrete composition can be produced by the following method. The components other than water (the blast furnace slag, at least one of the binder performance-exhibiting material and cement, etc.) are put into a mixer in a thermostatic chamber at 20 ℃ and dry-stirred, and then water is put into the mixer and the mixture is subjected to main stirring.
The apparatus such as a mixer is not particularly limited as long as it can be generally used for a concrete composition, and may be appropriately selected according to the purpose.