KR101379085B1 - Artificial stone and method for producing the same - Google Patents

Abstract

Using a large amount of land, such as dredged soil, as a material, an artificial stone having strength greater than semi-hard pavement and lighter than concrete is provided. A hydration hardened body obtained by hydration-curing a kneaded material of a mixed material containing an earth, a binder and a granulated steelmaking slag, wherein the mass per unit volume is 2000 to 2200 kg / m ³ . Since a large amount of ITO, such as dredged soil, is used as a material, such an effective use can be achieved, and since it has a strength higher than quasi-hard stone and is lighter than concrete, it is particularly useful for stone applications requiring strength, durability, and lightness. will be.

Description

Artificial stone and its manufacturing method {ARTIFICIAL STONE AND METHOD FOR PRODUCING THE SAME}

The present invention relates to an artificial stone obtained by solidifying Ito, such as dredged soil, with a binder, and a manufacturing method thereof.

Fragile Ito, represented by dredged soil, occurs along the route dredging and various civil works. Among them, those which are useful as civil engineering materials such as sand can be used as they are, such as shallow composition, backfilling, etc., but in the case of Ito which has a high ratio of silt, water is used. There are many things in the state of), and since the strength as the soil can hardly be expected, it often becomes a waste.

In order to effectively use Ito, various techniques have been proposed and implemented conventionally. The most representative of them is a technique for improving the characteristics as soil and using it with high quality soil. For example, various techniques for adding cement and lime to Ito and improving the characteristics of the ground have been shown in the "Stable Treatment Method of Soft Ground by Lime" by the Japan Lime Association.

In addition, Patent Literature 1 discloses a technique for improving the strength by mixing steel slag with dredged soil. In this technique, the strength of dredged soil is mainly caused by a pozzolanic reaction with CaO powder of steel slag and Si, Al, etc. of dredged soil. It is reforming. In addition, Patent Literature 2 discloses a technique in which a converter slag containing free CaaO and blast furnace cement are added to the soft soil to perform solidification treatment (improving strength). .

However, such a method is a property improvement as a soil material, and even if strength is expressed, it is limited to the use as soil only.

On the other hand, Patent Document 3 discloses a method of mixing a solidified material made of blast furnace slag, quicklime, fly ash and the like with dredged soil and solidifying to obtain a block material (solidified body). have. In this method, about 40-60 (mass part) solidified material is added with respect to dredged soil 100 (mass part) containing a water content, and the kneaded material is solidified and the block material is manufactured.

Japanese Patent Publication No. 2009-121167 Japanese Patent Laid-Open No. 2006-231208 Japanese Patent Publication No. 2008-182898

Since concrete materials (blocks) have a large specific gravity, they are materials suitable for marine blocks and the like which require stability. On the other hand, on the other hand, when applied to the block etc. which are provided in a soft ground, there exists a problem that it sinks to the ground and will not fulfill its role. In addition, the backfill material or the like of concrete has a smaller specific gravity, so the pressure applied to the wall becomes smaller, so that the economic efficiency of the whole construction body becomes higher, and therefore it is desirable to be as light as possible.

This point and the method of patent document 3 are said to be able to manufacture the lightweight block material of about 1.45-1.65 g / cm < ³ > in apparent density. However, since no aggregate is used at all, long-term durability and volume stability are not so expected, and there is a high possibility of breakage during use. The block material is the strength obtained by the method of Patent Document 3 is a 6N / mm ² to about average, maximum, even a mere degree 8N / mm ^2. In order to use it as a substitute for stone or concrete material, the strength (9.8 N / mm ² or more) of quasi-hard stone or more prescribed in JIS-A-5006: 1995 (rubble) is required. However, the strength of the block material obtained in Patent Literature 3 is the lowest level of curbstone (less than 9.8 N / mm ² ) and is considerably higher than the improvement level of the soil material, but various uses as a substitute for stone or concrete material It is not sufficient strength for use.

Accordingly, an object of the present invention is to solve the problems of the prior art as described above, and to provide an artificial stone that can be used in a large amount of ITO such as dredged soil as a material, and has a strength of semi-pumice or more and is lighter than concrete. have.

In addition, another object of the present invention is to provide a manufacturing method capable of stably manufacturing such artificial stone.

MEANS TO SOLVE THE PROBLEM The present inventors paid careful attention to light weight of ITO, such as dredged soil, and, as a result, repeated examinations to solve the above problems, and as a result, by using a mixed material in which steelmaking slag was further added to Ito and the binder, the strength of the semi-hard pumice was increased. It was found that a stone (hydration hardened body) that is lighter than the concrete can be obtained.

This invention is made | formed based on such a discovery, and makes the following a summary.

[1] A hydrate cured product obtained by hydration-curing a kneaded mixture of a mixed material including an earth, a binder and a granulated steel slag, wherein the mass per unit volume is 2000 to 2200 kg / m ³ . Lightweight artificial stone.

[2] The lightweight artificial stone according to the above [1], wherein the uniaxial compressive strength after curing for 28 days is 15 N / mm ² or more.

[3] The light-weight artificial stone described in [1] or [2], wherein the binder contains 80 to 95 mass% of blast furnace slag fine powder, and the remainder is usually Portland cement, lime powder, slaked lime, or blast furnace. Lightweight artificial stone, characterized in that at least one selected from cement.

[4] The light-weight artificial stone described in [1] or [2], wherein the binder contains 80 to 95 mass% of blast furnace slag fine powder and fly ash in total, and the balance is usually contained in Portland cement, lime powder, slaked lime and blast furnace cement. Lightweight artificial stone, characterized in that at least one selected, the fly ash is 30% by mass or less of the blast furnace slag fine powder.

[5] The light-weight artificial stone according to any one of [1] to [4], wherein the steelmaking slag ages the slag containing 0.5% by mass or more of free CaO, and has a differentiation rate of 2.5% or less. Lightweight artificial stone characterized by the steelmaking slag.

[6] A method for producing the lightweight artificial stone according to any one of the above [1] to [5], comprising Ito, a binder and a granulated steelmaking slag having a water content of 180 to 250%. And a mixed material having a ratio of 40 to 55% by volume of ITO to the granulated steel slag and a blending amount of the steelmaking slag of 750 kg / m ³ or more per volume of mixed material, and hydrating and curing the kneaded material. Method of making stone.

[7] The method for producing a light-weight artificial stone, wherein the dredged soil generated by the dredging construction is used as dredged soil stored as dredged soil in the manufacturing method of the above [6].

Since the artificial stone of this invention can use a large amount of land, such as dredged soil, as a material, such an effective use can be aimed at. Moreover, since it has a strength more than semi-hard pumice and is lighter than concrete, it is especially useful for stone applications in which strength, durability, and light weight are required. Moreover, according to the manufacturing method of this invention, such an artificial stone can be manufactured stably.

1 is a relation between the ratio of the dredged soil in the mixed material and the mass per unit volume of the hydrated hardened body for the hydrated hardened body obtained from a mixed material composed of a dredged soil and a binder (blast furnace slag fine powder + alkali stimulant) and a natural crushed stone and natural sand. A graph representing.
Fig. 2 is a graph showing the strength of a hydrated cured body obtained by using a mixed material composed of a dredged soil, a binder (fine blast furnace slag + alkali stimulant) and aggregate, and using natural crushed stone, natural sand and steelmaking slag as aggregates.
3 is an explanatory diagram showing an embodiment in the case of using dredged soil stored in a dredged soil dump as ITO in the present invention.

The artificial stone of the present invention is a hydration hardened body obtained by hydrating and curing a kneaded material of a mixed material containing an earth, a binder and a granulated steelmaking slag, and has a mass per unit volume of 2000 to 2200 kg / m ³ .

The present inventors paid attention to the lightness of the dredged soil and examined the mixing conditions for expressing the strength of a hydrated hardened body (hereinafter, referred to as "solidified body") using a large amount of dredged soil as a material. First, the present inventors produced a solidified body in which only the blast furnace slag powder and the alkali stimulant were added to the dredged soil as a binder, but only a solid solid which had a small specific gravity and was easily broken by impact. In particular, when the ratio of dredged soils increased, the whole became agglomerates of powdery substance, softened, weakened to abrasion, etc., and it was also found that stability as a stone could not be expected because it was light.

Therefore, the present inventors produced the solidified body which further added natural crushed stone and natural sand as aggregate. However, under this condition, when the mass per unit volume is 2000 kg / m <^3> or more, and it is trying to make a thing equivalent to a quasi-pumice, it turned out that it is necessary to reduce the ratio of dredged soil in a mixed material to less than 35 volume%. Fig. 1 shows the relationship between the proportion of dredged soil in the mixed material and the mass per unit volume of the solid material with respect to the solidified body obtained by a mixed material composed of a dredged soil, a binder (blast furnace slag fine powder + alkali stimulant) and a natural crushed stone and natural sand as aggregates. Indicates. Of course, such a solid body (artificial stone) can also be said to be useful as a material in its own way, but considering the effective use of dredged soil, the amount of dredged soil is not sufficient.

MEANS TO SOLVE THE PROBLEM The present inventors further examined the measures which solve the above point, examined several aggregates with a high specific gravity, and started again. However, in the examination, it was found that the strength of the solidified body tends to be slightly lower than the strength expected from the added blast furnace slag powder and the alkali stimulant. That is, it was found that even when a material (aggregate) having a large specific gravity was simply blended, the strength was not expressed as expected. Accordingly, the inventors of the present inventors have conducted studies on this cause and found that since dredged soil has an action of adsorbing alkaline powder, it is possible to inhibit the pozzolanic reaction, which is a basic reaction of solidification of cement and blast furnace slag fine powder. .

The present inventors thought that solving this point could produce a solid having a stable strength and specific gravity, and as a result of further studies, it was found that steelmaking slag may be blended as aggregate. 2, the strength of the solidified body manufactured using natural crushed stone, natural sand, and steelmaking slag as aggregate is shown. In this production test, the mixed material is 50% by volume of dredged soil, and the amount of aggregate is 25% by volume (natural crushed stone, natural sand: about 660 kg / m ³ , steelmaking slag: about 800 kg / m ³ ). Alkaline stimulants (usually Portland cement) were used together with blast furnace slag powder. In addition, as steelmaking slag, what stabilized the converter decarburization slag by steam aging was used. According to FIG. 2, the solidified body which used steelmaking slag for aggregate has the high intensity | strength compared with the solidified body which used natural crushed stone and natural sand for aggregate. This reason is not necessarily clear, but it can be considered as follows. That is, since steelmaking slag is an oxide containing a large amount of Ca powder, Ca ion and OH ion are supplied when steelmaking slag contacts with water. As a result of alleviating the reaction inhibiting factors caused by the dredged soil as described above, it is considered that a solid having a high strength has been obtained.

Therefore, by mixing and hydrating and curing the mixed material in which the granulated steelmaking slag and the binder are mixed with Ito, a hydrated cured product having moderate specific gravity and high strength can be obtained while using Ito in a large amount.

If the mass per unit volume of the artificial stone is less than 2000 kg / m ^{3, it is} less than the specific gravity used as the standard of the semi-hard stone described in JIS-A-5006: 1995. This is suitable for applying to soft ground and the like. However, it becomes easy to flow by waves, and stability of the role which an artificial stone should play originally falls. On the other hand, in the case of more than 2200kg / m ^3, is in the average weight of the level of semi pumice, applied to applications in which light weight (輕量) is desired, the significant difference (有意差) in the case of using the conventional stone Disappears. In addition, it is difficult to secure sufficient amount of dredged soil. For this reason, the mass per unit volume shall be 2000-2200 kg / m <^3> .

Further, the strength of the artificial stone has JIS-A-5006: If one or more semi pumice equivalent specified by 1995, that is 28 days curing unconfined compressive strength to 9.8N / mm ² or more after the good. Moreover, although natural stone is stable in strength, in the case of a solid, since imbalance etc. generate | occur | produce according to a compounding condition, it is more preferable that it is 15 N / mm <^2> or more by uniaxial compressive strength after 28 days of hardening.

Dredged soil is typical of the soil used in the present invention, but in addition, for example, mud generated from excavation work, construction sludge and the like can be mentioned. Here, itato generally means the thing which cannot carry out a bandit and shows the fluidity which a person cannot walk on it. As a rough strength, the cone index prescribed | regulated by JIS-A-1228: 2009 (a cone index test method of hardened soil) is 200 N / mm <^2> or less.

Ito represented by dredged soil is more effective in adsorbing ions (alkaline powder) as the amount of deposited soil increases, and in the prior art, it is difficult to obtain a solid having a suitable strength, and thus the present invention is particularly useful. Specifically, the present invention can be said to be particularly useful when targeting the soil containing 70 vol% or more of soil particles (sedimentary soil powder) having a particle diameter of 0.075 mm or less.

As will be described later, it may be used in a proportion of 40% by volume or more in the mixed material.

Examples of the binder include blast furnace slag fine powder, blast furnace slag fine powder added with an alkali stimulant, blast furnace cement, ordinary portland cement, and the like, and one or more of them can be used.

In addition, it is preferable to add an alkali stimulator to the blast furnace slag fine powder as a binder from the viewpoint of reducing the environmental load without using natural materials as much as possible, and securing the strength of the solidified body and the manufacturing cost. By using an alkali stimulant together with the blast furnace slag fine powder as a binder, the hydraulic environment of the blast furnace slag fine powder can be exhibited by creating an alkaline environment. That is, the hydration reaction of blast furnace slag fine powder can be accelerated | stimulated, and the intensity | strength of solidified body can be ensured. In addition, when portland cement is usually used as the binder, the pH increase when the solid is immersed in water is larger than when the alkali stimulant is used together with the blast furnace slag powder. Therefore, when considering the load to the surrounding environment, it is suitable to use an alkali stimulant together with the blast furnace slag fine powder.

As the alkali stimulant, for example, one or more kinds of lime powder, slaked lime, ordinary portland cement, blast furnace cement and the like can be used. In this case, it is preferable that 80-95 mass% of fine blast furnace slag powders are contained, and remainder is 1 or more types chosen from lime powder, slaked lime, ordinary portland cement, and blast furnace cement. When using an alkali stimulant together with blast furnace slag fine powder as a binder, when the ratio of blast furnace slag fine powder is 80 mass% or more, an excess alkali component will not remain in a solid body. Therefore, when using a solid in the sea etc., the load of alkali to a seawater environment is small. It is also economically advantageous. On the other hand, even if the ratio of blast furnace slag fine powder exceeds 95 mass%, it can knead | mix and solidify. However, when it is 95 mass% or less, since it is easy to disperse stably, the effect of a stimulant becomes small for the alkali suppression effect of dredged soil, etc., the effect of adding blast furnace slag powder is high, and it is necessary to use various raw materials. It is economically feasible because there is no facility load.

Although the kind of steelmaking slag which is an aggregate is not specifically limited, The molten iron preliminary slag (talin slag, a degreasing slag, desulfurization slag etc.), converter decarburization slag, an electric furnace slag, etc. are mentioned, One or more of these can be used. have. The steelmaking slag is preferably one having a particle size of 25 mm or less. It is also possible to use a particle size larger than this. However, even when the steel slag contains free CaO and stabilized by steam aging or the like, when the slag particle size is large, there is a high possibility that free CaO remains inside, causing expansion and defects in long term use. There is a possibility. In addition, since only the fine powder acts as aggregate, that is, volume stability and durability decrease, the proportion of particles having a particle diameter of 0.15 mm or more is more preferably 80% by mass or more of the whole steelmaking slag.

In addition, there is no particular limitation on the composition of steelmaking slag. However, the higher the basicity (CaO / SiO ₂ ) is preferable because the effect of increasing the strength is increased. However, if it is too high, the residual amount of free CaO will tend to become large, as mentioned later. In addition, in the case of a high base, even if the steelmaking slag is stabilized in advance by steam aging or the like, the basic problem is eliminated. However, since the aging treatment tends to become powdery, it serves as an aggregate. It is difficult to secure granularity. Moreover, since the intrinsic amount of free CaO also increases, it may be necessary to make aging time longer than usual, or there may be a case where free CaaO remains inside and the imbalance of volume stability becomes large. Therefore, the basicity (CaO / SiO ₂ ) is preferably about _2.0 to 5.0.

In addition, when the slag produced | generated in the steelmaking process contains 0.5 mass% or more of free CaO, the steelmaking slag is aged and made into the differentiation rate 2.5% or less, and then the material (aggregate) of this invention. It is preferable to use as. For slag having a relatively high basicity, free CaO remains in many cases. Free CaO has the advantage that it quickly becomes Ca (OH) ₂ by contact with water and is easily ionized to be involved in the reaction. On the other hand, free CaOO remaining in the interior of the slag particles expands when they come into contact with water that has penetrated, resulting in fragmentation inside the particles, which may cause defects in the solid. Therefore, for steelmaking slag containing 0.5% by mass or more of free CaO, aging (usually, steam aging, etc.) beforehand and hydrating free CaO with Ca (OH) ₂ will not cause a volume change when used as aggregate. It is preferable because it is not. Aging may be performed to such an extent that the slag differentiation rate is 2.5% or less.

Here, the mineral phase constituting the solid particles of Ito is completely different depending on the dredging area and the occurrence history. Therefore, depending on the type of dredged soil, Ca content supplied from steelmaking slag may become excessive, and the reactivity of kneaded material and the pH of the water which contacted hardened | cured material may arise. As a countermeasure, it is also conceivable to reduce the amount of steel slag blended to reduce the supply of Ca powder, but the weight of the cured product becomes lighter and the volume stability also decreases. In such a case, it is preferable to mix | blend fly ash in addition to blast furnace slag fine powder as a binder.

Since fly ash is mainly composed of amorphous SiO ₂ and Al ₂ O ₃ , it can be expected that the pozzolanic reaction occurs more quickly than the crystalline material when excessive alkali is generated. However, when the fly ash is excessively blended, the amount of Ca in the binder is too small, and the stability of the reaction of the original dredged soil, steelmaking slag and the binder may be impaired. For this reason, when mix | blending fly ash, it is preferable to make the compounding quantity into 30 mass% or less with respect to blast furnace slag fine powder.

Therefore, in the case of using an alkali stimulant together with the blast furnace slag fine powder as the binder, the total content of the blast furnace slag fine powder and the fly ash is 80-95 mass% for the same reason as described above, and the balance is usually Portland cement, lime powder, slaked lime. It is preferable that it consists of 1 or more types chosen from blast furnace cement, and makes fly ash 30 mass% or less with respect to blast furnace slag fine powder.

As described above, the artificial stone of the present invention can use a large amount of dredged soil, and can also effectively use steelmaking slag, which is an industrial by-product, and furthermore, has a high strength equivalent to quasi-pumice or more and is lighter than concrete. For this reason, it is very useful as a stone installed in soft ground.

Next, the manufacturing method of the artificial stone of this invention is demonstrated.

In the manufacturing method of the artificial stone of this invention, steelmaking slag which is an earth, a binder, and aggregate is mix | blended, the mixed material which added water as needed is kneaded, this kneaded material is hydrate-hardened, and an artificial stone is obtained.

Since the present invention aims to effectively use Ito represented by dredged soil, it is preferable that the ratio of Ito in the mixed material is as large as possible, and therefore, the ratio of Ito to the steelmaking slag of Ito, the binder and the granular phase in the mixed material (original Ito). The ratio including the water contained in) is preferably 40% by volume or more. On the other hand, the proportion of ITO becomes easy to 60 volume is%, and the mass per unit volume of 2000kg / m ³ or larger, because the ratio of the aggregate does not lower, solidified is not not stay, a sufficient durability to secure It becomes easy. For this reason, the ratio of ITO with respect to ITO, a binder, and a granulated slag of steel in a mixed material is 40 to 60 volume%.

Moreover, in more preferable manufacturing conditions, it contains the earth, the binder, and the granulated steelmaking slag with water content of 180-250%, and the ratio of the earth with respect to the earth, the binder and the steelmaking slag of a granular phase is 40-60 volume%. The kneaded material having a blended amount of steelmaking slag of 750 kg / m ³ or more per volume of mixed material is kneaded, and the kneaded material is hydrated and cured. Here, the water content of dredged soil is calculated as water content = (A / B) x 100 when the amount of water contained in the dredged soil is A (mass%) and the solid content is B (mass%).

According to such preferred production conditions, a hydrated cured product having a mass per unit volume of 2000 to 2200 kg / m ³ , 28 days of curing, having a uniaxial compressive strength of 15 N / mm ² or more and less unbalanced characteristics can be stably produced. .

When kneading the mixed material having a proportion of dredged soil of 50% by volume and the steel slag content of 1000 kg / m ³ , and hydrating and curing the kneaded material to obtain a solid, a slump of the mixed material and a solid of The properties were investigated. The results are shown in Table 1. In addition, the intensity | strength of a solid body is uniaxial compressive strength after 28 days of curing measured by the method similar to an Example. According to Table 1, when the dredged soil water content is less than 180%, the solidified body has sufficient characteristics, but because the mixed material has no fluidity (no slump), industrial production is difficult, and even if it can be manufactured, the unbalance of the characteristic becomes large. . On the other hand, when the water content of dredged soil is 240%, the strength begins to decrease, and at 260%, the strength decreases significantly. Therefore, 180-250% is preferable and, as for the water content of dredged soil, 240% or less is more preferable.

In addition, from the viewpoint of supplying Ca ions and OH ions as described above, the steelmaking slag also needs to be blended in a predetermined amount or more in the mixed material in order to ensure the volume stability of the solidified body, and 750 kg / per volume of the mixed material. It is preferable to mix | blend m <^3> or more, and 1000 kg / m <^3> or more is more preferable. However, when the blending amount of steelmaking slag is 1450 kg / m ³ or less, the unit volume mass of the solidified body does not become excessive, and it is not necessary to reduce the weight by using water in a large amount, and thus sufficient strength can be obtained. 1450 kg / m <^3> or less is preferable.

Ito, such as dredged soil, removes foreign matter by a sieve or the like as necessary. As a kneading means for the mixed material, for example, a kneading facility for fresh concrete may be used, but it may be carried out in a yard such as outdoors using a heavy machinery for civil engineering such as a shovel.

In order to solidify the kneaded material, for example, it may be poured into a suitable mold to solidify and cure (hydration hardening), or may be cast in a layered form such as outdoors to solidify and cure (hydration hardening). In particular, when producing a large amount of stone, it is preferable to pour a layer in the yard.

The period of solidification and curing is until the target compressive strength can be obtained and is generally about 7 days or more.

The obtained stone is crushed to an appropriate size as necessary. This crushing treatment may be carried out using a crusher. Further, when the kneaded material is poured into the yard in the form of a layer as described above, the solids of the yard may be roughly crushed by a breaker, and then crushed by a crusher. good. In addition, a crushed solidified body (mass) is usually classified by a sieve to obtain a mass of a predetermined size. For example, when used as a submerged breakwater material or the like, a mass of about 150 to 500 mm is obtained.

The dredged soils generated by dredging work vary in water content depending on the location of dredging. Moreover, when aquaculture (seaweed, oysters, etc.) of aquaculture etc. is performed in the vicinity of dredging construction, fouling of the seawater by dredging construction may affect aquatic products. Therefore, dredging work cannot be carried out through the year, and there is a limitation in the construction time (seasonal). When implementing this invention in such a situation, it is preferable to store the dredged soil which generate | occur | produced in dredging construction in a dredged soil dump, and to manufacture solidified body using the dredged soil stored in this dredged soil dump. Thereby, the following effects etc. can be acquired.

(i) Even if there is a variation in the water content of the dredged soil depending on the place of dredging, the water content of the dredged soil can be averaged by storing it in the dredged soil dump.

(ii) Even when there is a time limit for the construction of dredging, and there is a time when dredged soil cannot be collected annually, it is possible to stably supply dredged soil to the solidified manufacturing process by storing it in dredged soil dump.

(iii) By storing the dredged soil in the dredged soil dump, it is possible to easily manage and adjust the water content ratio.

3 shows an embodiment of the present invention using a dredged soil dump, and the dredged soil generated by the dredging construction is stored in the dredged soil dump. Although the shape and structure of dredged dumps are arbitrary, for example, earth and sand can be piled up in a yard, and a ring-shaped dike may be made and dredged soil may be stored inside. Dredged soil generated by dredging construction is transferred to and stored in dredged soil dump regardless of its water content and other properties and conditions. From the dredged soil dump, it is suitably supplied as ITO to the solidified body (artificial stone) manufacturing process, and a lightweight artificial stone is obtained by the manufacturing method mentioned above.

[Example]

The ingredients are blended and kneaded under the mixing conditions shown in Tables 2 and 3 (mixed for 5 minutes in a 0.75 m ³ mixing plant and discharged after a predetermined time), and the kneaded material of the mixed material is 100 mm in diameter x 200 mm in size. It molded by the mold and solidified, and manufactured the solidified body (artificial stone). The dredged soil was made up of 90% by volume of sedimentary soil collected from the water of Tokyo Bay, and water was added to adjust the water as needed. Moreover, as steelmaking slag which is an aggregate, steam aging was carried out to converter slag containing 3.5 mass% of free CaO, and the differentiation rate was made into 1.5% (particle size 0-25 mm; particle diameter 0.15 mm or more 80 mass% or more), Steelmaking slag A and steelmaking slag B with different surface density were used. The uniaxial compressive strength of the solid after 28 days of curing was measured by a compression test (JIS-A-1108: 2006). The results are shown in Tables 2 and 3 together with the unit volume mass of the solids and the like.

According to Table 2 and Table 3, the solidified body of the example of this invention has obtained the suitable unit volume mass (2000-2200 kg / m <^3> ) and high intensity | strength. On the other hand, the solidified bodies of the comparative examples Nos. 10 to 14 and 33 have too low water content of dredged soil, too much use of steelmaking slag, too much proportion of dredged soil, and do not use steelmaking slag. The unit volume mass is inappropriate.

Claims (11)

A hydration hardening body obtained by hydrating and curing a kneaded material of a mixed material containing a steelmaking slag having a differentiation rate of Ito, a binder, and a granular phase of 2.5% or less, and has a mass per unit volume. Light weight artificial stone, characterized in that 2000 ~ 2200kg / m ³ . The method of claim 1,
Lightweight artificial stone, characterized in that the uniaxial compressive strength after curing for 28 days is 15N / mm ² or more. The method of claim 1,
A light-weight artificial stone, characterized in that the binder contains 80 to 95 mass% of blast furnace slag powder, and the balance is at least one selected from portland cement, lime powder, slaked lime and blast furnace cement. 3. The method of claim 2,
A light-weight artificial stone, characterized in that the binder contains 80 to 95 mass% of blast furnace slag powder, and the balance is at least one selected from portland cement, lime powder, slaked lime and blast furnace cement. The method of claim 1,
The binder contains 80 to 95 mass% of blast furnace slag powder and fly ash in total, and the balance is usually at least one selected from Portland cement, lime powder, slaked lime and blast furnace cement. It is 30 mass% or less, light weight artificial stone. 3. The method of claim 2,
The binder contains 80 to 95 mass% of blast furnace slag powder and fly ash in total, and the balance is usually at least one selected from Portland cement, lime powder, slaked lime and blast furnace cement. It is 30 mass% or less, light weight artificial stone. 7. The method according to any one of claims 1 to 6,
The steelmaking slag is a steelmaking slag that is aged to 2.5% or less by aging a slag containing 0.5% by mass or more of free CaO. As a method of manufacturing the lightweight artificial stone according to any one of claims 1 to 6,
It contains Ito, binder and powdered steelmaking slag having a water content of 180 to 250%, and the ratio of Ito to Ito, binder and powdered steelmaking slag is 40 to 55% by volume, and the amount of the steelmaking slag is mixed. A method for producing a lightweight artificial stone, characterized by kneading a mixed material having a volume of at least 750 kg / m ³ and hydrating and curing the kneaded product. As a method of manufacturing the lightweight artificial stone according to claim 7,
It contains Ito, binder and powdered steelmaking slag having a water content of 180 to 250%, and the ratio of Ito to Ito, binder and powdered steelmaking slag is 40 to 55% by volume, and the amount of the steelmaking slag is mixed. A method for producing a lightweight artificial stone, characterized by kneading a mixed material having a volume of at least 750 kg / m ³ and hydrating and curing the kneaded product. 9. The method of claim 8,
A method for producing lightweight artificial stone, comprising dredged soil stored in a dredged soil dump as Ito, as dredged soil generated by dredging construction. 10. The method of claim 9,
A method for producing lightweight artificial stone, comprising dredged soil stored in a dredged soil dump as Ito, as dredged soil generated by dredging construction.

Images