JPS6253466B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of using a moisture regulating material for fine aggregate, and removes moisture attached to fine grain materials such as sand and sludge under conditions where it is not disturbed by wind power or the like. Mortar or concrete that can smoothly and efficiently adjust the yield within the appropriate range and determine the primary and secondary water amounts with high precision to obtain a product with little breathing, excellent strength, and low coefficient of variation. The purpose of the present invention is to provide a method for preparing such a raw kneaded material.

River sand or similar fine-grained materials are so-called fine aggregates and are indispensable materials for various types of construction or civil engineering that use cement today.Of course, they have been commonly used since ancient times, and In some cases, sea sand, water slag, or sludge are being used as substitutes. However, such fine-grained materials have adhering moisture, and this adhering moisture value usually fluctuates in a variety of ways and over a wide range. In other words, the source of such river sand is outdoors, such as a riverbed, and even if it is collected and deposited in a yard, there is hardly any special roofing, so it is difficult to collect or deposit it in a yard. Due to both transportation and storage conditions, there is an extremely high possibility that it will come into contact with river water or rain and dew.On the other hand, because of the fine grain size of sand, it has an extremely large specific surface area, and it is inevitable that it will contain water that adheres to the surface. and
In addition, since moisture is retained in the voids between these particles, the adhering moisture is always present, and moreover, it constantly changes depending on the weather conditions. The same thing is also observed in the sea sand, water slag sand, etc. mentioned above, and it is particularly likely that foreign components are mixed in due to the collection conditions in these sands. Even in such cases, clay and other mud particles are deposited, and these substances cause various problems when used as described above. On the other hand, when preparing a cement mixture using such sand, the water-cement ratio (hereinafter referred to as W/C) and cement-sand ratio (hereinafter referred to as C/S), or when making concrete, their The blending ratio of coarse aggregate (G) such as gravel (hereinafter referred to as S/G or C/G) to either or both of cement and sand affects the strength and fluidity (formability, construction workability, etc.) of the resulting compact. It is clear that excessive water content will cause separation and breathing in any case, and will be a major cause of a decrease in strength, while too little water will cause molding problems. This impairs the properties and injection properties, and even if auxiliary treatments such as continuous vibration and compression are used in combination, a dense structure cannot be formed, which also causes a decrease in strength and other product defects. Therefore, although it is essential to properly determine the W/C as described above to obtain a desirable product, achieve smooth injection molding, and obtain effective spraying, The fact that the amount of water adhering to sand fluctuates as described above and that it is impossible to accurately grasp and manage this makes it virtually impossible to properly determine the above-mentioned relationship, and W/C Not only that, but the S/C is also unstable, and in the end it is not possible to achieve the desired strength or molding work. Of course, there are methods of drying this sand to absolute dryness or measuring it in water, but a large amount is required. In addition, the former consumes a large amount of heat energy and time, and the latter also requires less man-hours to completely penetrate the sand grains and release air (JIS (According to the 2011 law, 24-hour immersion is required) and the amount of man-hours required to drain the water afterwards is significantly increased.

As mentioned above, it is natural that the adhesion and contamination of foreign components will change the performance of the product.In particular, salt adhering to sea sand can lead to corrosion of reinforcing steel, so it is strictly regulated, and JIS etc. Although salt removal methods are prescribed, a large amount of clean water is consumed in washing sea sand for such salt removal, its handling is complicated, and of course, difficult treatment is required for dehydration after salt removal washing. shall be.

In order to dehydrate the surface of such granular materials, Japanese Patent Laid-Open Publication No. 1983-1983 discloses that the granular materials are dispersed using wind power, and the water is dehydrated by the impact force of the scattered granular materials.
This is proposed in No. 54358, but it is clear that this would require a fairly strong wind force, and it is natural that this wind flow would flow turbulently within the casing of the equipment and blow out around the equipment. The force ejected from the typhoon alone is as strong as a typhoon, or even stronger. In other words, if it were carried out inside a factory, it would blow through the factory like a typhoon, and even if it was carried out outdoors, it would blow away the surrounding earth and sand, making it difficult for workers to get close to the equipment. An even stronger pressure airflow is generated, and the behavior of the granular material after the impact is reversed is also disturbed, especially in the case of sand grains, the sand grains are blown out of the case by the airflow from the case.
The processing results will be greatly disturbed and the work itself will inevitably become unstable.

The present inventors scattered fine aggregate such as sand as described above using centrifugal force without using wind power, etc., and caused the dispersed flying particles to collide with the plate surface, and the impact force at the time of the collision was The adhering moisture is transferred to the colliding plate surface, and the adhering moisture is adjusted by inverting and falling the fine aggregate from the plate surface.The particle behavior is less likely to be disturbed by air currents inside the case, and generally The amount of water remaining on the particles is inversely proportional to the above-mentioned flight speed and centrifugal force. Therefore, by appropriately selecting the degree of centrifugal force, the amount of water attached to the sand grains that reverse and fall from the impact plate can be made approximately constant, and a desirable improvement in yield can be achieved. Using the moisture stabilized fine aggregate obtained in this way,
It allows for reasonable mortar or concrete adjustment.

An example of an apparatus for carrying out the method of the present invention as described above is as shown in the accompanying drawings, in which a rotating disk 2 is mounted below a fine-grain material supplying means 1 such as a hopper. A loading port 11 from the hopper 1 faces the central portion of the rotating disk 2, and a dispersion piece 7 is disposed on the peripheral side thereof. A shaft cylinder 12 rotatably provided to the outside of the charging port
The shaft cylinder 12 is assembled to the fixed cylinder 13 with a bearing 3 interposed therebetween, and the pulley 15 attached to the upper part of the shaft cylinder 12 is connected to the pulley 5 of the motor 4. A belt 14 is suspended between the two and rotated at a required speed. However, an annular collision plate 6 is provided at an appropriate distance on the circumferential side of the rotating disk 2 as described above, and can be attached to and detached from the bell-shaped guide body 9 which is inclined downwardly in the casing 10. At the bottom of the guiding body 9, dividing means 8, 8a, and 8b are arranged in a ring in multiple stages, and the lowest dividing means 8b connects the lower region of the guiding body 9 with the casing 10,
The partitioning means 8b is connected to the other partitioning means 8a, 8 by means of a connecting plate 18.
As shown in the figure, these are arranged in stages.

As shown in the figure, the upper end of each of the dividing means 8 to 8b is formed into a knife shape, and this portion is disposed opposite to the inner surface of the guide member 9 with a gap at least large enough to allow liquid and air to pass through. The fine grain material moving along the surface of the guide member 9 is separated from the wall surface.

In some cases, an annular rotating plate 2a with its circumferential side bent slightly downward may be attached to the outer periphery of the rotating disk 2 as described above, as shown by the imaginary line. In this case, the sand grains are scattered downward to some extent, and the setting position of the collision plate 6 is lower, but even if the dispersion piece 7 is not specially arranged, the sand grains spread on the two surfaces of the disk can be scattered. On the other hand, when the sand particles scatter and separate, an effective centrifugal force can be imparted by the frictional action of the sand grains in the downward bending region. However, in such a case, by making the distance between each of the separating means 8 to 8b and the surface of the guide member 9 even smaller than in the illustrated case, the sand grains can be preferably separated, and the same effect as described above can be achieved. . A belt conveyor or the like is installed in front of the hopper 1 to continuously feed sand grains.

Furthermore, if preferable operating conditions are adopted in the above-mentioned apparatus as in the embodiment described later, what is discharged along the guiding part 9 surface in the above-mentioned apparatus will be water and substantial mud. You can release it as is.

However, such favorable operating conditions may not always be obtained depending on the properties of the applied sand grains, etc. In such cases, the material that has fallen from the lower end of the guiding member 9 to the outside of the separating means 8b may be appropriately removed. Of course, it is possible to carry out sedimentation separation or other treatment to separate the fine granules, and charge them into the hopper 1 using a conveyor or the like for reprocessing. In addition, the moisture removed from the fine granule material by the treatment of the present invention can be recovered and used as appropriate without simply discharging it. Used for concrete mixing.

A concrete device that takes these relationships into consideration is as shown in FIG. 2, in which the receiving gutter 19 is slightly inclined below the guide body 9 in the device shown in FIG. In addition, the lower part of the sorting means 8b is narrowed as shown in the figure, and a discharge belt conveyor 20 is connected to this.
is arranged, and the conditioned sand is always carried out by the conveyor 20 in a state in which it is slightly accumulated in the throttle opening 20a, so that the inside of this sorting means 8a is substantially sealed, and the above-mentioned receiving gutter is 19
A discharge port 19a is provided at the lower inclined portion of the drain tank 19 so that water removed from the fine granule material is allowed to fall into a hopper-shaped receiver 17 provided in a drainage tank 18. Also, a scraping piece 2 is provided at the bottom of such a receiver 17.
A scraping conveyor 21 such as a so-called water conveyor is provided in which the solid content settled at the bottom of the receiver 17 is scraped up to the outside of the drain tank 18. Water is pumped up by a required water pumping mechanism (not shown) provided with a water pipe 22 having an inlet 23 and sent to a mixer section for kneading mortar or concrete as described above. A water supply pipe 25 having a water level detection mechanism 24 is provided on one side of the water tank 18 so as to keep the water level of the drain tank 18 constant at all times. Water pipe 22 mentioned above
In some cases, it may be guided to the receiving gutter 19 part and the receiving gutter 1
It can be used for the purpose of injecting water to clean the inside of the hopper 9, or for pre-adding water to the fine granule material that is guided to the base of the conveyor 30 and fed into the hopper 1. That is, the present invention ultimately uses impact force to remove water adhering to the surface of fine granular material, and it seems pointless to add water to the water to be removed in advance. In some cases, the fine grain material may be in a dry state that does not reach the moisture content adjusted for removal, and in this case, the moisture content will not be uniform even after careful removal adjustment processing. In addition, it is inevitable that each fine grain material contains a certain amount of mud, and since this mud has viscosity, there is a possibility that it will stick to the 6 surfaces of the impact plate, especially if the fine grain material to be treated has a low moisture value. In such cases, it is very important to increase the moisture content of the fine grain material to be treated in advance.In other words, water that is removed from the fine grain material and flows down the wall surface can cause damage to the six surfaces of the collision plate, etc. It also allows mud and other particles that tend to adhere to the surface to flow down.

Furthermore, if there is a high possibility that mud or the like will adhere to the collision plate 6, the motor 4a installed above the hopper 1, as shown in the embodiment in FIG.
A vertical shaft 27 driven by the vertical shaft 27 is suspended down to the collision plate 6 portion, and a cleaning piece 28 is arranged on the vertical shaft 27, and the collision plate 6 portion is rotated slowly (for example, 10 times or less per minute) of the vertical shaft 27. It is possible to perform scraping cleaning. If a highly sticky mud adhesion layer is formed on the 6th surface of the collision plate, it will act as a buffer layer and impair the adjustment effect that utilizes the impact energy. There is a high possibility that the fine-grained material itself will be captured by the adhesion layer due to mud and the like, and the impact will not be reversed. By appropriately performing the cleaning, it is possible to effectively carry out moisture adjustment treatment without these disadvantages.

Note that a screw 29 is provided on the vertical shaft 27 as described above, if necessary, so that the fine grain material from the hopper 1 is constantly supplied onto the rotating disk 2. In other words, it is clear that it is undesirable for the amount of fine grain material supplied to the rotating disk 2 to fluctuate extremely in order to obtain constant moisture control.
Favorable supply and operation can be obtained by achieving the steady supply by driving by a motor 4a separate from the motor 4a.

A specific example of the method of the present invention using the above-mentioned apparatus will be described below first with respect to its adjustment process.

Adjustment example 1 Water-containing Megawa sand produced in Kimitsu, Chiba Prefecture (water absorption rate 2.25%, coarse grain rate 3.27), which varies in the range of 4% to 25% of the amount of attached water depending on the equipment shown in the above drawing.
A rotating disk 2 with a diameter of 450 mm is used, and the rotating disk 2 is rotated every minute by a motor 4.
It was rotated at a speed of 1250 revolutions to cause the supplied sand grains to collide with the collision plate 6. The sand grain supply rate to hopper 1 is 25 m ³ /hr as water-containing sand, and 5 to 40 /min on the conveyor feeding into hopper 1.
However, under the rotational conditions of the rotary disk 2 as described above, the sand carried out by the conveyor was kept sealed while ensuring that the sand accumulated in the lower part of the sorting means 8b was sealed with the accumulated sand. The result of sampling every minute and measuring the water content is 8.79 to 8.93
%, and the amount of attached water is 6.54 to 6.58
It was confirmed that the recovery rate was 24.1m 3 /hr and the yield was 24.1m ³ /hr.
The weight loss reached 96.2%, and the weight loss was essentially recognized as mud.

Furthermore, under the same conditions as above, when the rotational speed of the rotating disk 2 was set to 1500 revolutions per minute, which was higher than in the above case, the moisture content measurement results for the sampling of sand carried out were 6.92 to 7.04% (the amount of water deposited).
4.66~4.77%), and the rotation speed is further increased to 1750%.
times/min, the moisture content is 5.79 to 5.88% (3.53 to 3.62% of adhering water), and in each case, the adhering amount is lower and the variation range is constant within a narrower range. It was confirmed that the recovery amount was 24.28m ³ /hr at 1500rpm,
At 1750 rpm, it was 24.52 m ³ /hr.

Adjustment Example 2 Medium-sized sea sand produced in Hiroshima Prefecture (water absorption rate 2.46%, coarse grain rate 2.62, salt content 0.33%) was treated with the same equipment as in Adjustment Example 1 above, and in this case, on the conveyor to the hopper, The treatment was carried out by adding 30 ml of water per minute.

That is, at this time, under the rotation conditions of the rotating disk 2 shown in the previous section of the above adjustment example, the water content of the obtained sampling was 8.56 to 8.71% (the amount of water landed).
6.40 to 6.55%), and even under the same rotation conditions, the amount of water deposited is low because it is medium-sized sand, and its salt content is 0.03%, so it can be used as it is for preparing fresh mortar or ready-mixed concrete. It was confirmed that the amount recovered was 23.8 m ³ /hr.

Similarly, the measured value of water contained in the sampling under the rotation conditions of the second stage of Adjustment Example 1 is 6.76 ~ at 1500 rpm.
6.83% (accompanying water landing amount 4.30-4.37%),
5.51~5.58% at 1750 rpm (attached water amount 3.05~
3.12%), and similar results were obtained with little variation, and the salt content in these cases was 0.028% and 0.027%, which of course could be used for concrete as is. .

In this case, in order to perform washing to remove the salt with fresh water according to the conventional salt removal treatment technology, it is necessary to perform a washing operation with at least the same amount of fresh water as the volume of the sea sand to be treated, as described above. To process 25 m ³ of sea sand corresponding to the example, 25-80 m ³ of fresh water is consumed. On the other hand, in the case of the present invention described above, the required water amount is only 1.8 m ³ /hr, which is 30×60 (minutes), and the amount of fresh water consumed is significantly reduced.

Moreover, the conventional salt removal treatment described above uses sprinklers or simple watering, and the salt removal effect varies considerably, for example, the average value is 0.03%.
Specifically, for example, it is 0.002 to 0.150%, and 0.04% is considered to be an industrially preferable range.
Although a considerable amount of substances that do not meet the following requirements are mixed in, in the case of the above adjustment example of the present invention, water is added evenly on the conveyor and impact separation is performed evenly and accurately, so it is 0.007 to 0.038%. It has been found that the range of variation is small, which is preferable from this point of view as well.

Preparation Example 3 Crushed water slag slag sand having a coarse grain ratio of 2.53 and a water absorption rate of 2.90% was treated in the same manner as described in Preparation Example 1.

In other words, when the speed is 1250 rpm, the water content in the sampling conducted every minute is 8.99 to 9.27% (the attached water is 6.09 to 6.37%).
%), and at 1750 rpm, the water content is 6.19 ~
6.28% (accompanying water 4.29-4.38%), and the amount recovered was 24.0 m ³ at 1250 rpm, 24.3 m ³ at 1500 m ³ , and 24.51 m ³ at 1750 rpm.

Specific examples of how to use the moisture regulating material as described above are as follows.

Usage example 1 To adjust cement mortar according to the conventional general method, we used near-dry Nakamegawa sand from Kimitsu, Chiba Prefecture, and the cement was 956Kg/ ^m3 , and the W/S ratio was 1:1.
35% C, 7.65% lignin sulfonic acid dispersant
When kneaded at a ratio of Kg/m ³ , considerable bubble generation was observed, and the fluidity of this mortar was 42 seconds using a J-funnel, and the breathing rate was 6% after 3 hours. The compressive strength of the compact after 3 days was 375 Kg/cm ² , 489 Kg/cm ² after 7 days, and 489 Kg/cm 2 after 28 days.
It was 563Kg/ ^cm2 . The coefficient of variation after 28 days is 15.3%.

On the other hand, as a reference example, when the same medium-sized sand as above was subjected to the moisture adjustment treatment according to the present invention and the rotating disk was rotated at 1750 rpm in the same manner as described in Adjustment Example 1, the water adhering to the surface was 3.53%. For river sand like above, 956 kg/m ³ of cement and C/S of 1:1 and W/C of 35% were added as above.
The fluidity of a mortar made by adding and mixing 301/m ³ of water (subtracting the amount of water adhering to the surface above) and 7.65 kg/m ³ of a lignin sulfonic acid dispersant is as follows: The freezing rate after 3 hours was 0.5%. The compressive strength of the product molded with such mortar after 3 days is 532.
Kg/cm ² , 698Kg/cm ² after 7 days, 790Kg/cm 2 after 28 days
cm ² and its coefficient of variation was 4.8%.

Further, according to the present invention, 16.47% of primary water was evenly added to and mixed with the above-mentioned medium-sized sand, which had been adjusted to have a surface adhesion water of 3.53% by using a rotating disk at a rotation speed of 1750 rpm, and then cement was mixed with C/C. Add and mix S = 1:1 to form a shell with a W/C of 20% on the surface of the sand grains, then add and knead 15% secondary water and 0.8% dispersant. The fluidity of the mortar was 19 seconds, and the rate of bleeding after 3 hours was zero. However, the compressive strength of the product formed with such mortar after 3 days is 619 kg/
cm ² , 739 Kg/cm ² after 7 days and 855 Kg/cm ² after 28 days, and the coefficient of variation is 2.2%. Compared to the conventional general method mentioned above, there is a significant increase in strength despite the same composition. It was confirmed that the product was obtained and of stable quality.

Usage example 2 Using the same medium-sized sand produced in Kimitsu as in usage example 1 using the conventional general method, cement was added at 347Kg/m ³ and C/
S=1:2, C/G=1:3.6, dispersant 3.5Kg/
The slump value of the concrete mixed at a ratio of m ³ and with a W/C of 42% was 2.1 cm, and considerable breathing and air bubbles were visually confirmed in this concrete.

However, the compressive strength of the molded product obtained with this concrete was 208 Kg/cm ² after 3 days, and 284 Kg/cm 2 after 7 days.
cm ² was 334 Kg/cm ² after 28 days, and its coefficient of variation was 17.4%.

On the other hand, as a reference example, the slump value of concrete that has been mixed and adjusted with the same mixing ratio and composition as above using the same medium-sized sand that has been subjected to the same adjustment treatment as in Application Example 1, with the amount of water adhering to the surface being 3.53%, is
8.2 cm, and some separation and breathing were observed, but the compressive strength after 3 days of the molded product obtained with such concrete was 274 Kg/cm ^2,7
The strength was 348 Kg/cm ² after 28 days, and 482 Kg/cm ² after 28 days, and the coefficient of variation was 8.2%, indicating that an increase in strength of nearly 50% was obtained and the range of variation was relatively small.

Further, according to the present invention, 6.47% primary water was added and mixed to the same 3.53% surface water-adjusted river sand as above, and then the amount of cement was added to be the same as above, and the W/C of the shell part was 20. % of shelling sand was obtained, and to this was mixed together with gravel, 22% of secondary water and a dispersant of 1% of the amount of cement were added to make concrete having the same composition as described above. However, the slump value of this concrete is 11.6 cm, and the compressive strength of the molded body made of this concrete after 3 days is
308Kg/cm ² , 382Kg/cm ² after 7 days, 513 after 28 days
Kg/cm ² and its coefficient of variation was 5.1%, and the strength was increased by about 50%, and stable concrete with a significantly small variation range could be obtained.

Application example 3 Concrete with the same composition as in application example 2 with an additional 1.5% steel fiber added by bulk ratio was adjusted and kneaded using a conventional conventional method, and the slump value was
It was visually confirmed that the concrete had a diameter of 1.5 cm and had large separation and breathing.
The bending strength after 28 days was 58 Kg/cm ² .

On the other hand, the slump value of steel fiber-containing concrete prepared by adjusting the water content according to the present invention and forming a shell with a W/C of 20% relative to the sand grains, and using this shell to give the same composition as above, was but
No separation or breathing was observed at 12.8 cm, and the bending strength of the molded product after 28 days was 92 Kg/cm ²
It was hot.

Usage example 4 Using the same river sand as in usage examples 1 to 3 above, spraying cement at 350Kg/m ³ and sand at 1120Kg/m3.
Kg/m ³ , coarse aggregate 700Kg/m ³ , quick setting agent 10.5Kg/
m ³ is mixed under dry conditions and pumped with high pressure air, water is added to the dry pumped material so that the W/C is 50% at the spray nozzle part, ), the rebound amount was approximately 35% and the amount of dust generated inside the tunnel was approximately 750 CPM. The compressive strength after 28 days of spraying is 232Kg/ ^cm3 , and its coefficient of variation is
It was 14.5%.

On the other hand, example 1 of using the same river sand as above.
In order to obtain a mortar with C/S of 1:1 using river sand with 3.53% water adhesion on the surface in the same way as in 3.-3, a shell layer with a W/C of 20% was added to the river sand. After forming, a mortar with good fluidity adjusted to W/C = 34.2% and dispersant of 0.6% (relative to the amount of cement) is pumped through one pipe, and C/C is sprayed through the other pipe. Sand and coarse aggregate, whose moisture content was adjusted to 3.53% in the same manner as above, were pumped under dry conditions so that S was 1:3.01 and S/A (A is coarse aggregate) was 56%. The material was mixed with a quick-setting agent at the nozzle part at a ratio of 1 part delivered from one pipe to 1.75 parts pumped from the other pipe, and the mixture was sprayed onto a vertical wall surface. The W/C in this shotcrete is 42% and the amount of cement is 352Kg/m ³
The rebound amount during spraying is 8.9%,
The amount of dust generated is 72 CPM, the compressive strength after 28 days of spraying is 542 Kg/cm ² , and the coefficient of variation is 3.2%, which is more than twice the strength of conventional general methods and one-fifth of the coefficient of variation. We were able to achieve a desirable spraying construction that was reduced in size.

According to the present invention as explained above, the adhering moisture of sand and other fine grain materials can be effectively adjusted under conditions where there is little disturbance from wind force or other forces, thereby making it possible to achieve an appropriate mixing ratio in practice compared to the conventional technology. For fine-grained materials such as sand, which could not be determined manually, it is possible to always obtain a preferable mixing ratio relationship, and also to accurately determine the amount of primary water, form a preferable shell for fine-grained materials, and add secondary water to this. By applying this treatment, it is possible to achieve the highest strength of the product under each compounding ratio condition, and to obtain a product of stable quality with a small range of variation.Moreover, it is possible to achieve mass production using this type of treatment. This invention has a large industrial effect as it can smoothly carry out industrially advantageous adjustment treatment with a small amount of loss during the treatment even if it is carried out on a regular basis.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the invention,
FIG. 1 is a sectional view showing an example of a device according to the present invention;
FIG. 2 is an explanatory diagram when a treatment system for the removed water is installed. In these drawings, 1 is a fine particle supply means, 2 is a rotating disk, 3 is a bearing, 4 is a motor, 5 is a pulley, 6 is a collision plate, 7 is a dispersion piece, 8,
8a and 8b are dividing means, 9 is a guide member, and 10 is a casing.

Claims (1)

[Scope of Claims] 1. Fine aggregate for mixing concrete is scattered by centrifugal force, the scattered fine aggregate caused by this centrifugal force collides with a wall surface, and the centrifugal force attempts to remove moisture adhering to the surface of the fine aggregate. At the same time, the amount of water to be added in the first stage is determined based on the adjusted moisture content of the fine particles separated and collected from the wall surface by the separating means, and after adding and mixing the moisture, powdered hydraulic material such as cement powder or gypsum powder is added. By adding and mixing, a shell of the powdered hydraulic substance is once formed on the surface of the fine aggregate, and the residual moisture is adjusted to the above-mentioned adjusted moisture value for the shelled fine aggregate to obtain the desired raw kneaded material. Calculate the secondary added water amount from
A method of using a moisture regulating material for fine granular materials, which comprises adding this second amount of added water to the shelled fine aggregate, and adding and mixing necessary powdered hydraulic substances and other additives. 2. A method of using a moisture regulating material for fine grain materials as set forth in claim 1, in which fine grain materials with impurities such as sea sand are treated by appropriately adding water to remove impurities and adjust the moisture content at the same time. .