JP5857995B2 - Manufacturing method of artificial stone - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method for producing an artificial stone material by placing a raw material mainly composed of steelmaking slag and fine powder of blast furnace slag and water into a yard and hydrating and curing the hydrated solidified body. .

There is known a hydrated solidified product obtained by kneading a raw material mainly composed of powdered steelmaking slag and blast furnace slag fine powder with water and hydrating and hardening the raw material (for example, Patent Document 1). Can be used as roadbed materials, civil engineering materials, harbor civil engineering materials, and other concrete substitutes.
As one method for producing such a hydrated solid product, there is known a method in which a kneaded material and water are placed in a yard and coarsely crushed after curing to obtain an artificial stone (Non-patent Document 1). . The amorphous artificial stone material obtained by this method is particularly suitable for harbor civil engineering materials such as covering stones, rooting stones, rubble stones, and submerged dike materials.

  The conventional manufacturing method of artificial stone as shown in Non-Patent Document 1 is to place a mixture of raw material and water in a wide area of the yard to level it, and to set the hydrated solidified body after curing to a concrete breaker or the like Are roughly crushed into block stones having a size of about 100 to 300 kg / piece. Patent Document 2 discloses a method in which a plurality of parallel ridges are provided in a yard and a kneaded material is placed in a groove between the ridges in order to improve the productivity of this method. In this method, since a slender hydrated solid body is formed between the ribs, in the rough crushing step, a lump stone material can be obtained simply by crushing the hydrated solid body in two directions in the width direction, and the rough crushing operation can be performed very efficiently. Therefore, an artificial stone made of a hydrated solidified slag material can be produced with high productivity.

JP 2001-270746 A JP 2009-107908 A

“Coastal Development Technology Library No.16, Steel Slag Hydrated Solid Technology Manual, Effective Utilization Technology of Steelmaking Slag”, March 2003, Coastal Development Technology Center

  In these artificial stone manufacturing methods, the upper surface of the casting is open. For this reason, the upper surface portion starts to evaporate immediately after placement, and the moisture necessary for hydration hardening is insufficient due to evaporation, and a weak reaction layer of several centimeters in thickness is formed from the upper surface of the placement object. There is a problem. When the fragile portion is crushed or classified to adjust the product particle size by pulverizing the solidified cast (hydrated solidified product), most of the fragile portion becomes finer and becomes less than the product particle size, thereby reducing the product yield. In particular, the effect is great at high temperatures in summer, increasing the amount of powder generated during crushing and reducing the strength of artificial stone. For this reason, the amount of powder under the sieve generated in the particle size adjustment process increases, resulting in a nonstandard product, which makes processing difficult. In order to prevent this, it is conceivable to repeat watering in order to keep the moisture on the surface even after placement, or to use a moisture retention sheet called a concrete curing mat. Because it is necessary to increase the number of staff, it is difficult to implement in terms of economy.

  Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, and to put a raw material mainly composed of steelmaking slag and blast furnace slag fine powder and water into a yard to hydrate and cure the water. The purpose of the present invention is to provide a production method capable of increasing the product yield without impairing the economy and producing the artificial stone with high productivity and low cost when coarsely crushing the solidified body to produce the artificial stone. .

  The present inventors have studied a method that can effectively and economically prevent drying of the upper surface of the casting when curing the raw material and water kneaded material (casting material) placed in the yard, Effective use of stone particles such as stone powder generated during the transportation and particle size adjustment of artificial stone products, and this powder is covered with moisture to cover the top surface of the cast and a water retention layer to prevent drying And found a method. In other words, in the transportation and particle size adjustment of artificial stone materials at the time of product shipment, artificial stone particles (including many fine particles) that are smaller than the product size are inevitably generated. If it is laid in layers with a certain thickness and water is sprinkled from above to form a water retaining layer, it takes several days for the water to evaporate from this layer, so the cast material covered with a granular layer It was found that the lowering of moisture on the upper surface can be suppressed.

The present invention has been made on the basis of such findings and has the following gist.
[1] A kneaded material (a) composed mainly of steelmaking slag and blast furnace slag fine powder is placed in the yard, and the cast (A) is hydrated and hardened, then roughly crushed and artificially In the method of manufacturing stone,
After placing the kneaded material (a) in the yard, the artificial stone material for covering the upper surface of the cast material (A) with a water-containing granular layer (B) and curing the cast material (A) in this state A manufacturing method of
The granular material layer (B) is one or more types of granular materials selected from granular stone materials generated during the manufacturing process of artificial stone materials and granular stone materials generated during handling of the manufactured artificial stone materials. And an average stone thickness of 2 cm or more, and a method for producing an artificial stone material.

[2] In the production method of [1], the moisture content of the granular material layer (B) is 20 to 50%, and the cast (A) is cured for 1 day or longer in that state. Stone manufacturing method.

[3] In the manufacturing method of [1] or [2 ] above, after the curing of the casting (A) is completed, the granular material layer (B) covering the top surface of the casting (A) is removed. A method for producing artificial stone.
[4] In the manufacturing method according to any one of [1] to [3 ] above, the artificial stone obtained by roughly crushing the cast (A) after completion of curing is sieved at an arbitrary point of time, and then granulated. A method for producing an artificial stone characterized by separating objects.
[5] In the production method according to any one of [1] to [4 ] above, the artificial material characterized by watering the granular material layer (B) at least once during the curing period of the cast article (A). Stone manufacturing method.

  According to the present invention, by covering the upper surface of the casting for obtaining a hydrated solidified body that is an artificial stone with a highly water-retaining powder layer, the upper part of the casting is dried during curing. Can be suppressed, the occurrence of defective strength development can be reduced, the product yield can be improved, and the productivity can be increased. Moreover, since the granular material generated from the manufactured artificial stone material etc. can be utilized for the granular material for a granular material layer, it can implement at low cost. Therefore, the product yield can be increased without impairing the economy, and the artificial stone can be manufactured with high productivity and low cost.

BRIEF DESCRIPTION OF THE DRAWINGS One Embodiment of the manufacturing method of this invention is shown in order of a process, A figure (a) is a top view, A figure (b) is sectional drawing which follows the XX line of Fig. (A). The other embodiment of the manufacturing method of this invention is shown, A figure (a) is a top view, A figure (b) is sectional drawing which follows the XX line of figure (a) The graph which shows the particle size distribution of the slip used for the granular material layer B in an Example Diagram showing the relationship between scratch width and compressive strength shown in the literature

In the present invention, a raw material mainly composed of steel slag and blast furnace slag fine powder and water kneaded product a are placed in a yard, and the cast product A is hydrated and hardened, and then roughly crushed to produce an artificial stone material. After the kneaded material a is placed in the yard, the upper surface of the cast material A is covered with a water-containing powder layer B (the powder layer B is laid on the cast material A). In this state, the cast object A is cured. In addition, having steelmaking slag and blast furnace slag fine powder as a main component means that they are contained in an amount of 50% by mass or more.
According to such a method for producing an artificial stone material of the present invention, the highly water-retaining powder layer suppresses the drying of the upper layer portion of the cast article during curing, and reduces the occurrence of poor strength development portions. It is possible to improve the product yield, and for the granular material for the granular material layer, the granular stone material generated from the manufactured artificial stone material can be used, so that it can be implemented at low cost. .

As the granular material b constituting the granular material layer B, for example, it is possible to use a granular stone material generated in the manufacturing process of the artificial stone material or a granular stone material generated during handling of the manufactured artificial stone material. Although it is preferable in that a granular stone material having a particle size smaller than the product particle size generated in the system can be effectively used, other granular stone materials or natural sand may be used alone or in combination. Examples of other granular stone materials include, but are not limited to, stone powder generated in a limestone factory. Artificial stones are often used for marine applications and are free of reinforcing bars, so there is no need to worry about rust expansion, so there is no problem even if sea sand is used when the production site is near the beach.
Therefore, in this invention, 1 or more types of the granular material b as mentioned above can be utilized for the granular material layer B. FIG.

  However, from the viewpoint described above, at least a part of the granular material b constituting the granular material layer B is a granular stone material generated in the manufacturing process of the artificial stone material, and a powder generated during handling of the manufactured artificial stone material It is preferable that it is 1 or more types of granular stone materials. These powdery stone materials are so-called “suri”. Among these, as the granular stone material generated in the manufacturing process of artificial stone material, for example, when further curing stone material roughly crushed in the yard, products generated when the stone material is sieved before or after the curing For example, an under-sieving portion having a particle size smaller than that of the particle size may be used. In addition, as for the granular stone material generated when handling the manufactured artificial stone material, for example, the sieving fraction less than the product particle size generated at the time of transportation for product shipment or at the time of delivery (for example, separated by a bucket type screen) Etc.).

  Although there is no special restriction | limiting in the particle size of the granular material b which comprises the granular material layer B, in order to suppress the evaporation of the water | moisture content from the granular material layer B, many small voids are formed in a layer. It is effective to saturate the gap with water. For this reason, what is calculated | required by the granular material b which comprises the granular material layer B is that a particle size distribution is continuous and an average particle diameter is small. Inherently, slippage caused by crushing or scraping between stones tends to satisfy this requirement. Specifically, the granular material b constituting the granular material layer B preferably has a particle size with a nominal diameter of 10 mm passing through a sieve of 70% by mass, and a particle size with a nominal diameter of 10 mm passing through a sieve is 100% by mass. Particularly preferred. Further, among the nominal diameters of 10 mm or less, it is preferable that the particle size distribution is continuous, and it is more preferable that the fraction passing through the sieve having a nominal diameter of 2.5 mm is 20% by mass or more.

  The water content ratio of the powder layer B is not particularly limited, but all the voids in the powder layer B composed of the powder particles b of the particle size as described above are filled with water and saturated. Therefore, the water content is preferably 20% or more. The smaller the particle size of the granular material b is, the more water is required to reach the saturated state. However, when the water content ratio exceeds 50%, breathing exceeds saturation and the tendency of the granular material layer to flow and flow out is large. Become. For this reason, the moisture content of the granular material layer B is preferably 20 to 50%, more preferably 25 to 40%. Here, the water content ratio of the granular material layer B is the water content ratio = (W / S) where the water content in the granular material layer B is W (mass%) and the solid content is S (mass%). ) × 100.

  The water content of the powder layer B may be adjusted at any stage. For example, (i) water is contained in the powder material b before laying on the casting A, (ii) What is necessary is just to implement one or more of watering the granular material layer B laid on the casting A. In addition, the watering of (ii) may be performed a plurality of times with an appropriate time including the curing period. That is, in the granular material layer B, the water retention time can be controlled depending on the layer thickness, but in addition to the moisture adjustment up to the start of curing, it is also possible to increase the amount of water by watering multiple times at regular intervals. is there. In the case where the placement of the kneaded material a in the yard continues every day, it is preferable to perform watering a plurality of times when watering can be repeated at a fixed time every day. The thickness can be made thinner than the case where one water spray is assumed.

  A wide variety of water sources can be used as the water (particularly water for watering) to be contained in the granular layer B as long as it is possible to prevent water shortage during the curing period of the casting A. . That is, there is no problem with seawater as long as it is manufactured for marine use as well as fresh water, rainwater, industrial water, and tap water. Furthermore, water that shows alkalinity with calcium ions, such as sludge water generated in the manufacturing process of artificial stone and water recovered during kneading with a mixer, is also preferable, and can contribute to an overwhelming reduction in the amount of wastewater generated during manufacturing. .

There is no particular limitation on the thickness of the granular layer B, and the appropriate thickness of the granular layer B varies depending on the number of days of curing and the frequency of water spraying, but when the average thickness is less than 2 cm, moisture evaporation is fast. In particular, at high temperatures in summer when the application of the present invention is effective, the water retention amount may be insufficient for the required curing time (especially when the number of watering is small). Therefore, the average thickness of the granular material layer B is preferably 2 cm or more, and more preferably 4 cm or more.
On the other hand, when the thickness of the powder layer B is increased, it is advantageous for moisture retention, but the proportion of the thickness of the powder layer (water retaining layer) is larger than the layer thickness of the casting A that is the product. It becomes uneconomical because the amount of granular material separated from the product after curing increases. In addition, when the layer thickness is increased to increase the water content of the entire granular layer B, the lower layer side of the granular layer B, that is, the portion in contact with the casting A is the granular layer B. Since the water content is higher than that of the upper layer portion, the separation from the cast article A may be deteriorated due to wetting when excessive water content is left after completion of curing. For this reason, the thickness of the granular material layer B is preferably 20 cm or less, and more preferably 10 cm or less.

  It is effective to lay the granular material layer B at the beginning of the period requiring the curing of the cast A, but (i) the granular material b of the granular layer B bites into the cast A. , Suppressing strength expression due to hydration of the cast A, or preventing the powder b from adhering to the cast A with low strength, and (ii) occasionally after the kneaded product a is cast. It is effective to adjust the timing so as not to hinder the operation of forming grooves and holes for providing fracture base points at intervals close to the product particle size ("stitching" described later). Substantially, after placing the placement object A and solidifying it to such an extent that the surface can be worked without roughening the surface, it is possible to suppress the generation amount less than the product particle size and improve the product yield. This is the most advantageous timing.

Although there is no special restriction | limiting in the curing period of the casting A, It can cure for one day or more in the state which covered the granular material layer B (preferably moisture content 20 to 50%) which contained the casting A upper surface. preferable.
After curing of the casting A, the powder layer B covering the top surface of the casting A is removed. The powder layer B may be removed by heavy machinery (for example, a backhoe provided with a bucket with no nails in the lower part) or manually, or by scraping to the side of the mold (outside the mold). In the case of using a slurry as the powder b, since the hydration reaction of the slurry itself has already been almost completed, there is almost no adhesion between the particles of the powder b and the particles to the casting A, and the backhoe Scraping with a bucket or scraping to the side of the mold (outside the mold), most of the powder b in the powder layer B can be easily removed / separated from the casting A, The particle size specification of (artificial stone) can be secured.

  For example, after laying and spraying the granular material layer B under the conditions of Invention Example 4 to be described later and curing for 3 days, a backhoe (bucket with no nails in the lower part) is used before rough crushing of the cast A Then, the granular material layer B was scraped off. At that time, 89% by mass of the granular material b of the granular material layer B could be separated and recovered without damaging the cast A, that is, without mixing from the cast A. The powders b that are not collected are only those that remain in the grooves provided in a streak pattern on the cast A or thinly remain on the cast A in order to facilitate rough crushing. Since the recovered granular material b does not include a new cast product, the particle size remains the same, and the hydration reaction is completed and there is no caking property. It can be reused for the granular material layer B provided on the product A. If a slight mixing of the cast A during the recovery of the powder b is allowed, the powder recovery rate of the backhoe can be 90% by mass or more.

After removing the powder layer B from the top of the cast A, the cast A (hydrated solid) is roughly crushed using a heavy machine to obtain a block stone. Usually, this rough crushing is performed using a heavy machine (for example, a concrete breaker).
In addition, when the casted product A is not sufficiently hydrated and hardened and coarsely crushed in a state where the compression strength is low, a large amount of fine particles are generated and the product yield tends to be lowered. When the strength becomes too high, crushing becomes difficult, and a small lump is generated to reduce the yield. Therefore, the curing period until the cast material A is roughly crushed is preferably about 1 to 7 days.
The block stone obtained by roughly crushing the cast A (hydrated solidified body) is scraped from the placement site with a shovel car or the like, and further cured for several weeks in a stock yard or the like. In general, lump stones obtained by rough crushing have a small diameter such as slurries in grizzly or heavy machinery skeleton buckets, etc. at any point in time, such as when moving from the place of placement or curing, shipping, or unloading. Classification (sieving) is performed to separate and remove the fine particles, resulting in a product.

In addition, in order to remove the granular material b that could not be removed from the cast A, the artificial stone obtained by roughly crushing the cast A after completion of curing was sieved at an arbitrary time. It is preferable to separate the granular material b, but the granular material is obtained by the above-described classification operation for removing small diameter and fine particles such as sludge from the block stone obtained by roughly crushing the cast A. b can be easily separated.
In order to pass the product specification that does not include small-diameter and fine-grained components, if it is necessary to thoroughly separate the granular material b, the granular material can be removed by scraping the granular material layer B before roughly crushing the cast A Separating a large part of the product b, and further performing classification as described above (classification for removing small-diameter and fine-grained components from the block stone obtained by roughly crushing the casting A), This is advantageous in that the efficiency of separation of the granular material b can be improved.

Hereinafter, preferable conditions of the production method of the present invention will be described.
The raw material mainly composed of the granular steelmaking slag and blast furnace slag fine powder used in the present invention is the aggregate in which the granular steelmaking slag becomes the main aggregate of the hydrated solidified body, and the blast furnace slag fine powder is the main binder of the hydrated solidified body. It becomes.
There is no special restriction on the type of granular steelmaking slag. Steelmaking slag includes converter decarburization slag, hot metal pretreatment slag (for example, dephosphorization slag, desiliconization slag), electric furnace slag, secondary refining slag, ingot slag, etc. It may be used. Among the steelmaking slags, the hot metal pretreatment slag is particularly preferable because not only the air aging is completed quickly because there is little free-CaO, but also cracking due to hydration expansion is difficult to occur because there is little free-MgO phase. .

In addition, the steelmaking slag may be one that has been subjected to natural aging or steam aging in advance, or one that has been subjected to various treatments such as carbonation treatment.
In steelmaking slag, the larger the particle size of the slag particles, the higher the possibility of containing free-CaO or free-MgO particles inside, and there is a higher possibility of problems in the expansion stability of the hydrated solidified body. A particle size of 25 mm or less is preferred.
Also, blast furnace slag fine powder, which is the main binder of hydrated solidified material, is JIS
It is preferable to use one that conforms to A 6206: 1997.

If necessary, the raw material may further contain one or more selected from powdered granulated blast furnace granulated slag, fly ash, alkali stimulating material, and the like.
The granulated blast furnace granulated slag is basically blended as a part of the aggregate, but has a weak hydraulic property. It solidifies upon stimulation and contributes to strength.
The fly ash acts as a pozzolanic substance, helps improve the strength at long-term ages, reduces the alkalinity of the hydrated solidified body as a whole, and reduces the amount of alkaline substance eluted when the hydrated solidified body is immersed in water. There is also a function to reduce.

As the alkali stimulating material, for example, a Ca-based material such as slaked lime or cement (Portland cement or the like) can be used. The ground granulated blast furnace slag has latent hydraulic properties, and curing is accelerated by alkali stimulation. For this reason, high intensity | strength can be obtained more stably by adding an alkali stimulating material.
As a general raw material blending ratio, for example, steelmaking slag is 60 to 85 mass%, blast furnace slag fine powder is about 5 to 30 mass% (the balance is water), and other components (blast furnace granulated slag as necessary) Add one or more of fly ash, alkali stimulant, etc.).

There is no particular limitation on the yard where the manufacturing method of the present invention is implemented, and it may be ordinary outdoor ground. In the present invention, the form in which the kneaded material a and the raw material mainly composed of steelmaking slag and blast furnace slag fine powder is placed in the yard is arbitrary. Therefore, for example, as shown in Non-Patent Document 1, the kneaded material a and the raw material water are cast in a wide range of the yard and leveled, and the cured product A (hydrated solidified product) is cured. You may make it coarsely crush. However, from the viewpoint of productivity, the method shown in Patent Document 2, that is, the following method (i) or (ii) is particularly preferable.
(I) A plurality of parallel ridges are provided in the yard, and the kneaded material a is placed in a groove between the ridges. That is, the groove between the ribs is used as a formwork.
(Ii) A ridge is provided in the yard, a mold plate parallel to the ridge is disposed, and the kneaded material a is placed in a groove between the ridge and the mold plate. That is, the groove between the ridge and the formwork plate is used as a formwork.

In addition, as shown in the examples described later, a formwork is formed by arranging formwork members (for example, plate-like or I-beam concrete members or steel members) in a yard, and a kneaded material a May be placed.
1A to 1D show an embodiment of the manufacturing method of the present invention in the order of steps. FIG. 1A is a plan view, and FIG. 1B is an XX line in FIG. FIG.
In this embodiment, first, as shown in FIG. 1A, a formwork member 2 (side plate) is arranged on an outdoor ground 1 to assemble a formwork 2, and steelmaking slag and blast furnace slag fines are assembled in the formwork 2. A kneaded product a of water and a raw material mainly composed of powder is cast (poured). Then, after this casting object A is allowed to stand for a certain period of time (for example, about 1 to 6 hours) and solidifies to such an extent that fluidity is lost, the upper surface of the casting object A is shown in FIG. It covers with the water-containing granular layer B, and the cast A is cured in that state. Usually, the granular material b is laid on the casting A using a heavy machine such as a backhoe. The granular material b may contain water in advance, or may be sprinkled after laying.

When curing of the casting A is completed, the granular material layer B is removed with a heavy machine or the like as shown in FIG. 1 (c), and then the mold 2 (member 20) is removed, and then FIG. As shown in Fig. 2, a heavy machine (for example, a concrete breaker) is used to crush (break) the position p at an appropriate interval in the longitudinal direction of the cast A (hydrated solidified body) in its width direction, and the massive stone 3 And This rough crushing interval is appropriately determined according to the size (particle size) of the stone to be produced. Thereby, since the lump stone material 3 is obtained only by crushing (breaking) the casting object A (hydrated solidified body) in the width direction, rough crushing work can be performed very efficiently.
The massive stone 3 obtained by roughly crushing the cast A (hydrated solidified body) is scraped out with a shovel car or the like, and further cured in a stock yard or the like for a certain period of time to become a product. In addition, the massive stone material 3 obtained by rough crushing is classified (sieved) at an arbitrary time, and the fine particles are separated.

Further, in order to perform rough crushing of the cast article A (hydrated solidified body) more efficiently, the cast article A is crushed in the width direction at appropriate positions in the longitudinal direction of the cast article A (that is, the cast article A is crushed in the width direction). A groove or a plurality of hole portions may be formed along the width direction of the placement object A at a position to be broken (hereinafter referred to as “streaching” to form such a groove or a plurality of hole portions). There is a case.)
FIG. 2 shows an embodiment thereof. FIG. 2A is a plan view, and FIGS. 2B-1 and 2B-2 are cross-sectional views taken along line XX of FIG. .

  In the case of FIG. 2 (b-1) at a position p (position at which the casting object A should be crushed in the width direction) at an appropriate interval in the longitudinal direction of the casting object A as shown in FIG. 2 (a). In FIG. 2 (b-2), a plurality of holes 4b are formed at intervals along the placement object width direction. . The formation method of these grooves 4a and hole portions 4b is arbitrary. For example, after the flowability of the kneaded material a placed is lost, a part of the work arm of a heavy machine (for example, a concrete breaker) is placed. It can be formed by pressing it into the inside from the upper surface of A. The groove 4a and the hole 4b may be formed after the kneaded material a is solidified to such an extent that the fluidity is lost (for example, about 60 to 120 minutes after the kneaded material a is placed).

Moreover, although the depth of the groove | channel 4a and the hole part 4b is arbitrary, it is preferable to set it as 50% or more of the thickness of the casting A, desirably 60% or more. Further, when the plurality of hole portions 4b are formed at intervals along the placement object width direction, the interval between adjacent hole portions 4b (distance between the outer edge portions of the hole portions) is set to be twice or less the hole diameter. It is preferable.
As shown in FIG. 2, if the groove 4a or the plurality of holes 4b are appropriately formed along the width direction at the position where the cast A should be roughly crushed (broken), it can be blown by a heavy machine such as a concrete breaker. The entire width of the casting A can be broken.

In this example, as a granular material of the granular material layer B, a particle having a particle size of 20 mm or less (a particle obtained by sieving according to JIS-A-1102) was used. FIG. 3 shows the particle size distribution of this gap, which is a particle size having a nominal diameter of 10 mm and passing through a sieve of 80% by mass or more. The original artificial stone material from which this gap was obtained was manufactured with the target of a compressive strength of 9.8 N / mm ² or more after standard curing on the 28th, and an aging material (bone) of converter slag having a particle size of 30 mm or less. Material) and blast furnace slag fine powder (bonding material), and fly ash and raw material containing ordinary Portland cement (each material is “Steel Slag Hydrated Solid Technology Manual (revised), February 2008”) The mixture was kneaded with water and this kneaded product was placed in a yard. This cast is roughly crushed in 3 days and cured for about 3 months in the air, then crushed with heavy machinery to adjust the particle size to produce an artificial stone product. What was sometimes generated during classification (sieving) was used.

In addition, according to a separately conducted test, when the above-mentioned particle size of 20 mm or less was used for the granular layer B, water was sprayed on the granular layer B, and breathing water began to be generated on the surface. The water content was 22%. In addition, when using a gap having a smaller particle diameter, the water content ratio during saturation when the same breathing water began to be generated is 25% when a gap having a particle diameter of 9.5 mm or less is used, and a particle diameter of 5 mm or less. When using a gap, it was 30%.
Moreover, in a part of Example, what mixed limestone powder | flour with said slip was used as a granular material.

Hereafter, the manufacturing procedure of the artificial stone material performed in the present Example is demonstrated.
Targeting artificial stones with a compressive strength of 9.8 N / mm ² or more after standard curing on the 28th, mainly consisting of aging material (aggregate) of converter slag with a particle size of 30 mm or less and blast furnace slag fine powder (binding material), In addition, raw materials containing fly ash and normal Portland cement (each material is blended in the standard range of “Technical Manual for Steel Slag Hydrated Solids (Revised Edition), February 2008)” are kneaded with water. A was set up in the outdoor yard during the daytime in the summer.

I-shaped concrete members (I-beams) are arranged to form a 4 m wide cast formwork, and the kneaded material a is poured directly from the concrete agitator car into this formwork, and the thickness is approximately 60 cm thick with a backhoe. Turned into. In addition, 2 hours after placing the kneaded material a, creasing was performed with a backhoe fixed to a bucket to which an iron plate having a height of 50 cm was attached.
After 3 hours have elapsed from the placement of the kneaded material a, the above-mentioned gap (powder particles having a particle size of 20 mm or less) is laid on the cast material A in the mold and leveled, and the upper surface of the cast material A The granular material layer B which covers was formed. In addition, about the thing with the thin thickness of the granular material layer B, it equalized by human power (use the dragonfly for ground maintenance). Water was sprinkled on the granular material layer B with a watering wheel or a hose, and watering was terminated when breathing water was seen. In some examples, watering was performed multiple times every 24 hours. Moreover, in some Examples, watering was performed with respect to the granular material b before laying, and watering was not performed with respect to the granular material layer B. In some embodiments, after 2 hours of placing the kneaded material a, the above-mentioned slip (powder particles having a particle size of 20 mm or less) is laid on the placed material A in the mold, and leveled. The granular material layer B which covers the upper surface of the structure A was formed, and creasing was performed immediately after that.
The maximum daily temperature during the test period was 33 to 36 ° C., and there was no rainfall of 1 mm or more during the curing period.

  After curing in the mold, the mold was removed, and the powder layer B was scraped off to the side of the casting A with a backhoe (bucket with no nails at the bottom). The granular material b scraped off was scraped up with a backhoe, moved from the placement site, and weighed in an on-vehicle state. The mass of the granular material at this time is defined as [x1]. The cast A from which the powder layer B was scraped was roughly crushed with a concrete breaker to obtain a block stone. In order to develop the strength, it was cured in place until 7 days after placing, and then transferred to the product yard. When moving to the product yard, screening with a skeleton bucket attached to the backhoe separates small and fine particles with a particle size of 150 mm or less, which is less than the product particle size, and weighs them to place the kneaded material a The ratio to the amount was calculated. Here, the product yield is higher as the smaller diameter and finer particle size is 150 mm or less. In addition, by the screening by the skeleton bucket, a slight residual amount (slack that constitutes the powder particle layer B) and a small diameter / fine particle part generated by the rough crushing of the placement object A are classified. However, assuming that the gap constituting the granular material layer B is sufficiently smaller than the hole of the skeleton bucket and the total amount is sieved, the above [x1] and the amount [x2] classified in the screening are added up. The amount obtained by subtracting the laying amount of the granular material layer B from the amount [X] was defined as the small and fine particles (particle size of 150 mm or less) generated by the rough crushing of the cast material A. Moreover, a part of the granular material layer B is sampled before being discharged from the mold, and the residual moisture of the granular material layer B is measured. With this moisture content, the total amount [X] of the granular material layer B is measured. The amount to subtract the laying amount was corrected.

In addition, the powder layer B is scraped by hand before rough crushing, and is marked on the upper surface of the cast object A that has been exposed. After rough crushing and 7 days after placement (or after 7 days of curing, coarse At the time of crushing), the part derived from the top surface of the massive stone found by marking is scratched with a scratch tester approved by the Japan Painted Floor Industry Association, and the width of the wound is measured to determine the top surface of the cast object. The strength of was evaluated. The scratch was adjusted to a load of 1.0 kg, and the strength was determined using the figure in the document “Noboru Yuasa et al., Summary of the Annual Meeting of the Architectural Institute of Japan, September 1999, p.677”. This figure is shown in FIG.
The above measurement results are shown in Table 1 together with the production conditions of each example. In Table 1, “-150 mm generation ratio (%)” is the ratio of the amount of small and fine particles having a particle diameter of 150 mm or less generated by rough crushing of the cast A to the cast amount of the kneaded product a. It is. The watering source is water used for adjusting the water content ratio of the powder layer B.

In Comparative Example 1, since there is no powder particle layer B, the upper portion of the casted material becomes insufficiently hydrated and solidified due to insufficient moisture, and many small and fine particles (particle size of 150 mm or less) are generated, resulting in a low product yield.
On the other hand, in each of Invention Examples 1 to 12 in which the granular material layer B is installed and water is retained, the product yield is improved as compared with Comparative Example 1.
The scratch width in the scratch test of Comparative Example 1 is as large as 1.52 mm. According to the estimation from FIG. 4, the compressive strength is expressed only up to about ² N / mm ² , and the target 28-day standard curing is performed. The compression strength after 7 days, which is the evaluation point of this example, is too low for the later compression strength of 9.8 N / mm ² or more.

In Invention Examples 2 to 5, the generation amount of small and fine particles (particle size of 150 mm or less) decreases as the thickness of the granular material layer B increases, and the product yield is improved as compared with the comparative examples. In addition, when Invention Example 2 in which the thickness of the granular material layer B is 10 cm and Invention Example 5 in which the thickness of the granular material layer B is 20 cm are compared, the amount of small diameter and fine particles (particle size of 150 mm or less) generated is It does n’t change much. According to the estimation from FIG. 4 based on the scratch width of the scratch test, both have developed a compressive strength of 7 to 8 N / mm ² , and the strength is greatly improved as compared with Comparative Example 1. Although the result of the scratch test is improved as the powder layer B is thickened, the improvement effect is almost saturated when the thickness of the powder layer B exceeds 10 cm based on the results of Invention Examples 2 and 5. To do.

Invention Example 6 is an example in which watering was carried out every day (3 times in total during the curing period), but the amount of small and fine particles (particle size of 150 mm or less) generated was the smallest. This is considered to be because the non-uniformity of the water spray and the non-uniformity of the portion that easily evaporates were suppressed, and the entire upper surface of the casting A was cured under sufficient moisture.
Inventive Example 7 is to adjust the water content in advance by watering the piles of the granular material b before laying the granular material layer B, and then laying it on the placement object A that has been laid with a backhoe, This is an example in which watering was not performed. If the amount of small and fine particles (particle size 150 mm or less) generated and the groove width in the scratch test are almost the same as those of Invention Example 3, and the water content of the powder layer B is the same, the timing of water content adjustment is It shows that it can be either before or after laying.
Invention Example 8 is a case where creasing is performed after laying the granular material layer B. Compared to Invention Example 3, the generation amount of small and fine particles (particle size of 150 mm or less) is increased. This is because (i) moisture evaporates from the inserted muscle, (ii) the strength of the powder layer B without hydration and solidification fell into the casting A halfway, and the strength decreased. This is probably because the product yield cannot be greatly improved. Therefore, it is shown that it is more advantageous to lay the granular material layer B after the creasing.

Inventive Example 9 is a mixture of the powder constituting the granular material layer B and finer stone powder than that, and there is almost no influence on the amount of small-diameter and fine-grained particles (particle size of 150 mm or less), The water content is increasing, which is considered advantageous for moisture retention.
Invention Example 10 uses seawater as the water contained in the powder layer B, and the amount of small and fine particles (particle size of 150 mm or less) is greatly reduced compared to the comparative example. Although the effect appears, the amount of small and fine particles (particle size of 150 mm or less) generated is slightly larger than Invention Example 3, which is under the same conditions except for the type of water. This is considered to be because the condensation reaction tends to be slightly delayed in the portion in contact with the casting A due to the buffering effect of seawater because seawater was used.

Invention Example 11 and Invention Example 3 have the same conditions except that the moisture content of the granular material layer B is 20% and 28%, respectively, but Invention Example 11 is slightly more than Invention Example 3 It can be seen that it is advantageous that the generation amount of small and fine particles (particle size of 150 mm or less) is high and the water content ratio is high.
However, in Invention Example 12 in which the moisture content of the powder layer B is 50%, there is an advantage that the generation amount of small and fine particles (particle size of 150 mm or less) can be suppressed even if the number of water sprays is small. The material layer B has begun to be in a slightly breathing state, and the efficiency of separation from the casting A has been slightly reduced.

DESCRIPTION OF SYMBOLS 1 Ground 2 Formwork 3 Block stone 4a Groove 4b Hole 20 Member A Placing thing B Powdery material layer a Kneaded material b Powdery material

Claims (5)

A raw material mainly composed of steelmaking slag and fine powder of blast furnace slag and water (a) are placed in the yard, the cast (A) is hydrated and hardened, and then roughly crushed to produce artificial stone. In the way to
After placing the kneaded material (a) in the yard, the artificial stone material for covering the upper surface of the cast material (A) with a water-containing granular layer (B) and curing the cast material (A) in this state A manufacturing method of
The granular material layer (B) is one or more types of granular materials selected from granular stone materials generated during the manufacturing process of artificial stone materials and granular stone materials generated during handling of the manufactured artificial stone materials. And an average stone thickness of 2 cm or more, and a method for producing an artificial stone material. Particulate matter layer a water ratio of (B) and 20-50%, process for producing an artificial stone according to claim 1, characterized in that the curing more than one day the droplet設物(A) in this state. After curing the completion of the punching設物(A), process for producing an artificial stone according to claim 1 or 2, characterized in that the removal of powder and granular material layer covering the upper surface of the punching設物(A) (B). According to an artificial stone obtained hit設物after curing completing (A) and crude crushing, and sieved at any time, any one of claims 1-3, characterized in that the separation of particulate matter Manufacturing method for artificial stone. During curing period of the punching設物(A), process for producing an artificial stone according to any one of claims 1 to 4, characterized in that water is sprayed at least once a granular material layer (B).

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