JP5705703B2 - Concrete production method - Google Patents

Description

  The present invention relates to a method for producing concrete, and more particularly to a technique for cooling an aggregate constituting the concrete.

  In general, when a large amount of concrete is required, such as for dam construction, cement and aggregates (coarse and fine aggregates) are placed in a batcher plant (concrete manufacturing facility) equipped with storage bins for storing materials. Materials are transported, and these materials are kneaded with water to produce concrete, and this concrete is placed in place with a crane or the like.

  In addition, concrete generates heat due to the heat of hydration of cement, and the temperature rises. For this reason, especially in the summer, when the temperature of the material rises according to the outside air temperature and the concrete kneading temperature rises, the expression of long-term strength is reduced, and plastic shrinkage cracks are likely to occur. In addition, in the case of mass concrete that is placed throughout the year such as dam concrete, there is a risk of cracking due to temperature stress due to a temperature difference from the winter season.

As a countermeasure for this, it is conceivable to lower the temperature of the concrete by cooling the material such as aggregate before kneading during the summer construction.
As a technique for cooling the aggregate or the like, for example, techniques described in Patent Documents 1 and 2 can be cited.

  In Patent Document 1, cooling is performed by feeding cold air (cooling air) to the aggregate that is supplied and staying in the storage bin (silo) and bringing the cold air into direct contact with the aggregate. Have been described.

  In Patent Document 2, water is contained in the surface of the aggregate by sprinkling the aggregate in the storage bin with a water spray nozzle from above, and then the inside of the airtight storage bin is evacuated. Thus, it is described that the surface water of the aggregate is evaporated and the aggregate is cooled by the latent heat of evaporation.

JP 62-74603 A JP-A-57-188317

By the way, at the time of manufacturing concrete, it is important in terms of the quality of the concrete to mix each material such as aggregate, cement, water and the like at a predesigned blending ratio (design blending).
In general, the surface water ratio of the aggregate is measured prior to supplying the aggregate to the storage bin, and the surface water volume corresponding to the measured surface water ratio is subtracted from the design water volume (water volume in the design formulation). Is set as the amount of water during mixing.

Here, especially in low slump concrete such as dam concrete, the amount of design water is small, so management of the water amount is very important for quality control of the concrete.
The quality of concrete can be evaluated by, for example, a slump test defined by JIS A 1101.

However, in patent document 1, when some aggregate used as the path | route of the cold wind dries, dispersion | variation will arise in the surface water rate of the aggregate in a storage bottle.
For this reason, since the dispersion | variation in the surface water amount of aggregate will generate | occur | produce after setting the water amount at the time of mixing, the quality of concrete may become unstable.

Further, in Patent Document 2, since water is sprayed directly on the surface of the aggregate, if the water spray is uneven, the surface water ratio of the aggregate in the storage bottle varies.
For this reason, since the dispersion | variation in the surface water amount of aggregate will generate | occur | produce after setting the water amount at the time of mixing, the quality of concrete may become unstable.

  In view of such a situation, an object of the present invention is to reduce the temperature of the manufactured concrete and stabilize the quality of the manufactured concrete.

  Therefore, in the present invention, the step of supplying and retaining the aggregate in the storage bottle, the step of cooling the outside air to generate cold air, the step of adding water to the generated cold air, and the water are added. Cooling the aggregate by blowing the cool air to the aggregate in the storage bin, and mixing the cooled aggregate supplied from the storage bin, cement, and water to produce concrete And a step of evaluating the consistency of the manufactured concrete, and a step of adjusting the amount of water added to the cold air and / or the air amount of the cold air based on the evaluated consistency.

  Here, the “concrete consistency” means the degree of fluidity / solidity of the concrete in the unsolidified state after mixing, or the degree of resistance to deformation or flow.

  According to the present invention, by adding moisture to the cold air, cooling of the aggregate in the storage bottle is promoted by vaporization of the moisture, so that the temperature of the manufactured concrete can be reduced.

  Further, according to the present invention, the amount of water added to the cold air and / or the air volume of the cold air is adjusted based on the evaluated consistency, thereby preventing local drying and excessive water content of the aggregate in the storage bottle. Since it can suppress, it can suppress that the surface water quantity of an aggregate varies, and, by extension, the quality of the concrete manufactured can be stabilized.

The figure which shows schematic structure of the concrete manufacturing system in one Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a schematic configuration of a concrete production system according to an embodiment of the present invention.
The concrete production system 1 is mainly composed of a batcher plant 2, a cold air pipe 3, a cold air device 4, and a watering device 5.

The batcher plant 2 is constructed by stacking devices corresponding to the concrete manufacturing process on the foundation frame 21 as a multi-level hierarchical structure.
The top floor is a receiving block 23 provided with a distribution chute 22. In this receiving material block 23, various aggregates sent from an above-ground aggregate yard (not shown) via a conveying device 24 (for example, a belt conveyor) are distributed by a distribution chute 22 and are stored in a lower storage block 25. Each type of aggregate is put into the storage bin 26 provided. Here, in this embodiment, G1 aggregate (particle size 150 to 80 mm), G2 aggregate (particle size 80 to 40 mm), G3 aggregate (particle size 40 to 20 mm), G4 aggregate (particle) Concrete is manufactured using 5 types of aggregates (diameter 20-5 mm) and S aggregates (particle size 5 mm or less). The aggregates G1 to G4 correspond to coarse aggregates, while the aggregate of S corresponds to fine aggregates.

  Each of the storage bins 26 provided corresponding to each of the five types of aggregates is connected to a cold air pipe 3, and the cold air from the cold air device 4 passes through each of the cold air pipes 3. It is supplied into the storage bin 26.

In the storage bin 26, the aggregate supplied from the distribution chute 22 stays.
In addition to the storage bin 26 for aggregate, the storage block 25 includes a storage bin (not shown) for storing cement pumped by air from a cement silo (not shown), and a cold water device (not shown). A storage bottle (not shown) for storing water (for example, about 6 ° C.) fed by a water pump (not shown) and a storage bottle (not shown) for storing the admixture are also provided.

  Below the storage block 25, a weighing block 27 is provided. The weighing block 27 is provided with a weighing bin corresponding to each storage bin. As for the aggregate, a measurement bin 28 is provided for each of the five types of aggregates.

  A kneading block 29 is provided below the measuring block 27. The kneading block 29 is provided with a mixer 30 for kneading each material measured and dispensed in each measuring bottle.

  A concrete hopper 31 for temporarily storing the concrete discharged from the mixer 30 is provided on the upper portion of the foundation frame 21 below the kneading block 29. The concrete temporarily stored in the concrete hopper 31 is appropriately discharged by opening and closing a discharge damper (not shown) provided in the lower part of the concrete hopper 31.

The cold air device 4 takes in outside air and cools it to generate cold air, and sends this cold air to the watering device 5 through the cold air pipe 3.
The cold air device 4 includes a chiller unit 41, a cooling tower 42, and a blower 43.

  The chiller unit 41 includes a refrigerant circuit (not shown). This refrigerant circuit forms a closed circuit filled with refrigerant, and includes a compressor, a radiator, an expansion valve, and an evaporator (not shown). In the refrigerant circuit, a vapor compression refrigeration cycle is performed by circulating the refrigerant. Then, the outside air is cooled by absorbing the heat of the outside air with an evaporator.

The cooling tower 42 is a device for releasing heat from the above-described radiator to the outside.
The blower 43 sends the air (cold air) cooled by the evaporator of the chiller unit 41 to the watering device 5 through the cold air pipe 3. Here, the air volume adjustment of the cold air can be realized, for example, by adjusting the operation speed of the blower 43.

  The watering device 5 includes a water tank, a spray water pipe, and a spray nozzle (not shown). The water storage tank is connected to the spray nozzle through a spray water pipe. A water pump (not shown) is installed in the spray water pipe between the water storage tank and the spray nozzle.

  The cold water (for example, about 6 ° C.) stored in the water storage tank is mist-injected into the cold air from the spray nozzle via the spray water pipe and the water pump. That is, in the watering device 5, water is added to the cold air by spraying cold water mist onto the cold air. Here, the adjustment of the amount of water added to the cold air (amount of spray water) can be realized, for example, by adjusting the operating rotational speed of the water pump installed in the spray water pipe.

The cold air to which moisture has been added by the water sprinkler 5 is supplied to the storage bin 26 via the cold air pipe 3 to cool the aggregate in the storage bin 26.
Next, a concrete manufacturing method using the concrete manufacturing system 1 will be described below.

  First, prior to supplying the aggregate into the storage bin 26, the aggregate is sampled and its surface water percentage is measured. Here, the surface water ratio means a ratio obtained by dividing the amount of surface water in the wet state (the amount of water adhering to the surface of the aggregate) by the mass of the aggregate in the surface dry state (surface dry saturated state). To do.

  Then, based on the measured value of the surface water ratio, the amount of water at the time of mixing (the amount of water measured in the measuring bottle) is set. Specifically, the surface water volume of the aggregate corresponding to the measured value of the surface water ratio is subtracted from the design water volume, and this is used as the water volume during mixing. That is, the amount of water at the time of mixing is adjusted based on the measured value of the surface water ratio so as to be the design water amount.

The aggregate whose surface water content has been measured is supplied into the storage bin 26 and stays for a certain period of time.
On the other hand, the cool air device 4 cools the outside air to generate cool air.
The cold air generated by the cold air device 4 is sent to the watering device 5 through the cold air pipe 3.

In the sprinkler 5, water is added to the cold air by spraying mist on the cold air.
The cold air to which moisture has been added by the watering device 5 is blown to the aggregate in the storage bin 26 via the cold air pipe 3, thereby cooling the aggregate.

  Aggregate from the storage bin 26 is weighed in the weighing bin 27 based on the on-site formulation and supplied to the mixer 30. Further, cement, water, and admixture from a storage bin (not shown) are separately measured in a measurement bin (not shown) based on the on-site blending and supplied to the mixer 30. The details of on-site formulation will be described in the examples described later.

In the mixer 30, aggregate, cement, water, and admixture are kneaded.
The concrete thus manufactured is appropriately discharged from a discharge damper (not shown) of the concrete hopper 31.

The consistency of the discharged concrete is evaluated.
As a method for evaluating consistency, for example, a slump test defined in JIS A 1101 and a standard VC test defined in JSCE-F 507-2007 can be used. In the present embodiment, a case where a slump test is used as a consistency evaluation method will be described below as an example.

  The manufactured concrete slump is measured by a slump test. Based on the measurement result, the amount of mist sprayed by the watering device 5 (in other words, the amount of water added to the cold air) and the cold air device 4 are measured. To adjust the amount of cold air supplied to the storage bin 26.

  In general, based on the measured value of the surface water content, coarse aggregate (G1 to G4), fine aggregate (S), on-site mix adjusted water mix, concrete mixed in a predetermined mixer for a predetermined time in advance It shows the same consistency as the concrete designed by testing. Specifically, when evaluating the consistency by a slump test, for example, if the slump value of the design planned at the time of test kneading is 8 cm, it is approximately within a certain range (for example, 8 cm ± 2.5 cm). Convergence (in other words, within acceptable limits) has been demonstrated.

  Therefore, when the measured value of the manufactured slump of the concrete is varied and smaller than the predetermined value as a whole, some aggregate that has become the path of the cold air is dried in the storage bin 26. Since the surface water amount of the aggregate is highly likely to vary, the amount of water added to the cold air is increased by the watering device 5. In this case, the amount of water added to the cold air is increased as the measured value of the slump is decreased. Thereby, since the local drying of an aggregate is suppressed, the dispersion | variation in the surface water amount of an aggregate is suppressed. Here, the predetermined value is a value corresponding to the allowable range of the consistency of concrete and is set in advance.

  In addition, when the measured values of the slump of the manufactured concrete are varied and smaller than the predetermined value as a whole, some aggregate that has become a path for cold air is dried in the storage bin 26. Since there is a high possibility that the surface water amount of the aggregate has a variation, the cool air device 4 reduces the air volume of the cool air. In this case, the air volume of the cold air is reduced as the measured value of the slump becomes smaller. Thereby, since the local drying of an aggregate is suppressed, the dispersion | variation in the surface water amount of an aggregate is suppressed.

  In addition, when the measured value of the slump of the produced concrete varies and is smaller than the predetermined value as a whole, in addition to performing the combination of an increase in the amount of water added to the cold air and a decrease in the air volume of the cold air, Any one of these may be implemented.

  On the other hand, when the measured values of the slumps of the produced concrete vary and are larger than the predetermined value as a whole, the water content of some aggregates that have become passages for the cold air in the storage bin 26 is excessive. Thus, since there is a high possibility that the surface water amount of the aggregate has a variation, the amount of water added to the cold air is reduced by the watering device 5. In this case, the amount of water added to the cold air is reduced as the measured value of the slump increases. Thereby, since the local excessive water | moisture content of an aggregate is suppressed, the dispersion | variation in the surface water amount of an aggregate is suppressed.

  Further, when the measured values of the slumps of the manufactured concrete are varied and larger than the predetermined value as a whole, the water content of some aggregates that have become passages for the cold air in the storage bin 26 is excessive. Thus, since there is a high possibility that the surface water amount of the aggregate varies, the cool air device 4 increases the air volume of the cool air. In this case, the air volume of the cold air is increased as the measured value of the slump increases. Thereby, since the local excessive water | moisture content of an aggregate is suppressed, the dispersion | variation in the surface water amount of an aggregate is suppressed.

  In addition, when the measured value of the slump of the produced concrete varies and is larger than the predetermined value as a whole, in addition to performing a combination of a decrease in the amount of water added to the cold air and an increase in the air volume of the cold air, Any one of these may be implemented.

  The adjustment of the amount of water added and the amount of air flow are considered to be affected by the outside air temperature and humidity, but it is not always necessary to adjust every hour or day. For example, it may be sufficient to adjust for each relatively long period of each month or season.

〔Example〕
Next, an embodiment to which the above-described concrete manufacturing method is applied will be described.
In this embodiment, the specifications and capabilities of the batcher plant 2 were as follows.
Mixer capacity: 6m ³
Number of mixers: 1 Kneading cycle time: 2 min
Working efficiency: 0.9
Kneading capacity: 6 m ³ × 1 unit × 60 min / h ÷ 2 min × 0.9 = 162 m ³ / h
Capacity of storage bins for aggregates G1-G4: 20m ³ each
Table 1 shows the design mix of concrete in this example.

本実施例では、ダム建設で用いられるＡ配合（外部配合）のコンクリートと、Ｂ配合（内部配合）のコンクリートとの２種類のコンクリートについて、上述のコンクリートの製造方法を適用した。

In this example, the above-described method for producing concrete was applied to two types of concrete, that is, concrete of A mix (external mix) used in dam construction and concrete of B mix (internal mix).

In Table 1, the water binder ratio is the weight ratio of water and binder. Here, the binder means a hardening material mainly made of cement.
The fine aggregate rate is the volume ratio of fine aggregates in the total aggregate.

The air amount means the amount of air contained in the concrete.
Moreover, the unit volume of water, binder, fine aggregate, and coarse aggregate each mean the weight (design weight) per 1 m ^{3 of} concrete.

Moreover, although it is not described in Table 1, the admixture was put into concrete.
Prior to supplying the aggregate into the storage bin 26, the aggregate was sampled and its surface water ratio was measured. The measurement results were as follows.

Coarse aggregate G1: 0.0%
Coarse aggregate G2: 0.3%
Coarse aggregate G3: 0.5%
Coarse aggregate G4: 1.0%
Fine aggregate S: 4.0%
Based on the measured value of the surface water ratio, the amount of water at the time of mixing was set, and this was used as the on-site formulation. This on-site formulation is shown in Table 2.

表２に示す現場配合では、表面水率の測定値に対応する骨材の表面水量を設計水量より差し引いて、これを混合時の水量とした。具体的には、Ａ配合のコンクリートに関しては、骨材全体での表面水量（３０ｋｇ／ｍ^３）を設計水量（１２４ｋｇ／ｍ^３（表１参照））より差し引いて、これを混合時の水量（９４ｋｇ／ｍ^３）とした。また、Ｂ配合のコンクリートに関しては、骨材全体での表面水量（３４ｋｇ／ｍ^３）を設計水量（１１５ｋｇ／ｍ^３（表１参照））より差し引いて、これを混合時の水量（８１ｋｇ／ｍ^３）とした。

In the on-site formulation shown in Table 2, the surface water volume of the aggregate corresponding to the measured value of the surface water ratio was subtracted from the design water volume, and this was used as the water volume during mixing. Specifically, for concrete containing A, the surface water amount (30 kg / m ³ ) of the aggregate as a whole is subtracted from the design water amount (124 kg / m ³ (see Table 1)), and this is the amount of water during mixing ( 94 kg / m ³ ). For concrete blended with B, the total surface water amount (34 kg / m ³ ) of the aggregate is subtracted from the design water amount (115 kg / m ³ (see Table 1)), and this is the amount of water during mixing (81 kg / m ³ ). ³ ).

In the on-site blending, the surface water amount was added to the design weight for the unit volume of fine aggregate and coarse aggregate.
Concrete with B blending was manufactured in the concrete manufacturing system 1 with the on-site blending shown in Table 2.

Here, the specifications and capabilities of the cold air device 4 were as follows.
Chiller unit: 270,000 kcal / h 37 kW × 2 units Cooling tower: 2 units Blower: 55 kW × 1 unit Further, the cold air pipe 3 is a steel pipe having a circular cross section, and the diameter thereof is 700 to 1000 mm.
Moreover, in the watering apparatus 5, the average value of the mist diameter injected was about 50 micrometers.

  First, in the concrete production system 1 under conditions of an air temperature of 32 ° C. and a humidity of 50%, the cold air device 4 and the water spray device 5 are not used (that is, the aggregate is not cooled by the cold air), Concrete was manufactured.

ここで、表３において、貯蔵ビン２６内の細骨材及び粗骨材の温度は、赤外線温度計で測定された。同様に、貯蔵ビン内のセメント及び水についても、各々の温度が周知の温度測定手段により測定された。 Table 3 shows the estimation result (heat balance sheet) of the concrete temperature in this case.

Here, in Table 3, the temperature of the fine aggregate and the coarse aggregate in the storage bin 26 was measured with an infrared thermometer. Similarly, the temperature of each cement and water in the storage bottle was measured by a well-known temperature measuring means.

The temperature of the fine aggregate and coarse aggregate in the storage bin 26 was 30.0 ° C., respectively.
The temperature of the binder in the storage bottle was 40.0 ° C.
The water temperature in the storage bottle was 6.0 ° C.

Under these conditions, the concrete temperature was estimated to be 27.2 ° C. using a heat balance sheet.
On the other hand, the measured concrete temperature was 29.0 ° C.

Therefore, as for the concrete temperature, the estimated value using the heat balance sheet was lower than the actually measured value.
Next, under conditions of an air temperature of 32 ° C. and a humidity of 50%, the concrete manufacturing system 1 uses the cold air device 4 and does not use the water spray device 5 (that is, cold air without adding moisture to the cold air). The aggregate of B was cooled) to produce B-mixed concrete. Here, the amount of cold air sent from the cold air device 4 into the storage bin 26 was 400 m ³ / min, and the temperature of the cold air was 10 ° C.

貯蔵ビン２６内の細骨材については、冷風装置４からの冷風により冷却されて、その温度が２４．０℃であった。 Table 4 shows the estimation result (heat balance sheet) of the concrete temperature in this case.

The fine aggregate in the storage bottle 26 was cooled by the cold air from the cold air device 4, and the temperature was 24.0 ° C.

The coarse aggregate in the storage bin 26 was cooled by the cold air from the cold air device 4, and the temperature was 23.0 ° C.
The temperature of the binder in the storage bottle was 40.0 ° C.

The water temperature in the storage bottle was 6.0 ° C.
Under this condition, the concrete temperature was estimated by a heat balance sheet to be 22.0 ° C.

On the other hand, the measured concrete temperature was 23.5 ° C.
Therefore, by using the cold wind device 4, the estimated value of the concrete temperature decreased by 5.2 ° C, and the actually measured value decreased by 5.5 ° C.

  Thereafter, the consistency was evaluated by measuring the concrete slump in a slump test. Specifically, the consistency of the manufactured concrete slump is evaluated by confirming whether it is within 3 cm ± 1.5 cm, which is the allowable range of the slump of the B-mixed concrete. It was. Here, the predetermined value in this example corresponds to 3 cm ± 1.5 cm which is an allowable range of the slump of the B blend concrete.

  As a result of the slump test, the measured value of the slump was 1 cm, which was below the predetermined value of 3 cm ± 1.5 cm. Therefore, there is a high possibility that a part of the aggregate that has become a passage for the cold air in the storage bin 26 is dried, and the surface water amount of the aggregate varies.

  In order to suppress the variation in the surface water amount of the aggregate, the watering device 5 was used together with the cold air device 4. Here, the amount of mist (amount of spray water) sprayed from the sprinkler 5 to the cold air was 10 liters / min, and the temperature of the spray water was 6 ° C.

  When the cold air to which moisture was added by mist was supplied to the aggregate in the storage bottle 26, the measured value of the concrete temperature was lowered to 22.5 ° C. That is, the cooling of the concrete was promoted by the mist spray to the cold air.

Moreover, it was 2-4 cm when the slump of the concrete manufactured, performing mist spray to cold air, was measured. That is, the measured slump value of the concrete was within the allowable range of the slump of the B-mixed concrete. Therefore, by relaxing local drying of the aggregate in the storage bin 26, variation in the surface water amount of the aggregate is suppressed, and the quality of the concrete is stabilized.
The above has been a description of the production of B-mixed concrete, but the same is true for the manufacture of A-mixed concrete, and the description thereof will be omitted.

  The cooling methods described in Patent Documents 1 and 2 are both methods for cooling the aggregate in a storage bin (silo) before the aggregate is transported to the concrete production system. Conventionally, in the production of concrete, fluctuations in the surface water volume of the aggregate impairs the stabilization of the quality of the concrete, and therefore, cooling methods resulting from fluctuations in the surface water volume have not been used much before the mixer. On the other hand, since the temperature of the cooled aggregate rises again due to the outside air temperature, it is advantageous in terms of cooling efficiency to cool the aggregate immediately before mixing. In this regard, according to the present embodiment, excellent cooling efficiency can be obtained by cooling the aggregate just before the mixer 30, and fluctuations in the surface water amount caused by cooling the aggregate just before the mixer 30 can be obtained. It can be suppressed to stabilize the quality of concrete.

  According to this embodiment, the cool air is cooled by the cool air device 4 to generate cool air, the water is added to the generated cool air by the water spray device 5, and the cold air to which the moisture is added is stored in the storage bottle 26. Spray the aggregate to cool the aggregate. Thereby, since the cooling of the aggregate in the storage bin 26 is promoted by the vaporization of the moisture added to the cold air, the temperature of the concrete to be manufactured can be reduced.

  Further, according to the present embodiment, the consistency of the manufactured concrete is evaluated, and the amount of water added to the cold air and / or the air volume of the cold air is adjusted based on the evaluation result. Thereby, since the local drying and excessive water content of the aggregate in the storage bin 26 can be suppressed, it is possible to suppress the surface water amount of the aggregate from varying, and consequently, the quality of the concrete to be manufactured is improved. Can be stabilized.

  Further, according to the present embodiment, prior to supplying the aggregate into the storage bin 26, the surface water ratio of the aggregate is measured, and the amount of water at the time of mixing is adjusted based on the measured value of the surface water ratio. Thereby, since concrete can be manufactured in a state very close to the design composition, high-quality concrete can be manufactured.

  Moreover, according to this embodiment, consistency is evaluated by measuring the slump of the produced concrete, and the amount of moisture added to the cold air is increased as the measured value of the slump decreases. Thereby, since it is possible to suppress drying of a part of the aggregate that has become a passage for the cold air in the storage bin 26, the variation in the surface water amount of the aggregate in the storage bin 26 can be reduced.

  Further, according to the present embodiment, the consistency is evaluated by measuring the slump of the produced concrete, and the amount of cold air is reduced as the measured value of the slump is reduced. Thereby, since it is possible to suppress drying of a part of the aggregate that has become a passage for the cold air in the storage bin 26, the variation in the surface water amount of the aggregate in the storage bin 26 can be reduced.

  In the present embodiment, the slump test defined in JIS A 1101 has been described as the consistency evaluation method. However, the consistency evaluation method is not limited to this, and for example, JSCE-F 507-2007. A defined standard VC test can be used.

  Further, in this embodiment, the consistency is regularly evaluated, but in addition to this, for example, the consistency of the manufactured concrete is continuously measured by using a viscosity measuring device. May be evaluated. Further, the consistency may be evaluated by measuring a current value of a drive motor (not shown) of the mixer 30.

DESCRIPTION OF SYMBOLS 1 Concrete manufacturing system 2 Batcher plant 3 Piping for cold air 4 Cooling air device 5 Water sprinkler 21 Base mount 22 Distribution chute 23 Receiving block 24 Conveyance device 25 Storage block 26 Storage bin 27 Measuring block 28 Measuring bin 29 Mixing block 30 Mixer 31 Concrete hopper 41 Chiller unit 42 Cooling tower 43 Blower

Claims (4)

Supplying and retaining the aggregate in the storage bin;
A step of cooling the outside air to generate cold air;
Adding water to the generated cold air;
A step of cooling the aggregate by blowing cold air to which the moisture has been added to the aggregate in the storage bottle;
Mixing the cooled aggregate, metered from the storage bin, cement, and water to produce concrete;
Evaluating the consistency of the manufactured concrete;
Adjusting the amount of water added to the cold air and / or the air volume of the cold air based on the evaluated consistency;
A method for producing concrete, comprising: Measuring the surface water content of the aggregate prior to supplying the aggregate into the storage bin;
The method for producing concrete according to claim 1, wherein the amount of water at the time of mixing is adjusted based on the measured value of the surface water ratio.   The consistency of the concrete is evaluated by measuring a slump of the manufactured concrete, and the amount of water added to the cold air is increased as the measured value of the slump decreases. Production method.   The consistency is evaluated by measuring a slump of the manufactured concrete, and the amount of cold air is reduced as the measured value of the slump decreases. Concrete manufacturing method.

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