JPH0716829A - Quality controller for ready-mixed concrete - Google Patents

Abstract

PURPOSE:To provide a required workability to ready-mixed concrete. CONSTITUTION:In kneading ready-mixed concrete, when a shaft torque signal 31 outputted from a shaft torque operator 30 for detecting a shaft torque value of a mixer 1 comes to a stable state, an operation start signal 33 is outputted from a stable state judging device 32. A replenishing admixture amount operator 46 evaluates a secondary admixture amount to be replenished to ready-mixed concrete on the basis of the shaft torque signal 31 and admixture replenishing amount data 45 stored in an admixture replenishing amount data storage device 44. A replenishing admixture supply controller 48 actuates a flow regulating valve 22 based on an admixture replenishing signal 47 from the admixture replenishing amount operator 46 to supply secondary admixture 43 to the ready- mixed concrete. In this manner, the ready-mixed concrete has a suitable workability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quality control device for ready-mixed concrete.

[0002]

2. Description of the Related Art Conventionally, ready-mixed concrete used for construction work has been prepared by mixing ready-mixed concrete constituent materials such as cement, water, sand and gravel (aggregate) in a ready-mixed concrete manufacturing facility such as batcher plant. Is manufactured by.

Workability (ease of flow, ease of driving) of ready-mixed concrete is slump value, slump flow value,
Although it can be expressed by a funnel time value, etc., even if the above-mentioned green concrete constituent materials are kneaded in a predetermined composition, each value representing workability due to the surface water content and particle size distribution of the aggregate is the design value. Can be different and this is
It also occurs in ready-mixed concrete manufacturing facilities where the management of raw concrete components is well controlled.

Therefore, conventionally, a worker operating a ready-mixed concrete production facility appropriately adjusts the amount of water supplied at the time of kneading the ready-mixed concrete based on experience, so that the ready-mixed concrete has a predetermined workability. I am trying.

[0005]

However, in recent years,
In high-quality concrete with excellent fluidity, such as compaction-free concrete, which has been researched and developed, the flow of green concrete will be impaired if the amount of water is not appropriate.

On the other hand, even if the surface water content of the gravel is detected by means of a moisture meter or the like, there is a measurement error, and it is difficult to always make the workability of the ready-mixed concrete an appropriate value.

[0007]

[Knowledge based on survey results] As a result of intensive studies by the inventors in order to solve the above problems, the following findings were obtained.

(1) As shown in FIG. 6, for mortar produced by kneading water, cement and sand with a mixer,
Further, when gravel, water, and an admixture are added to produce ready-mixed concrete, the rotation speed of the mixer is set to a medium speed, and the mixer axial torque when the ready-mixed concrete is kneaded (current value when the mixer is driven by a motor). / Rotation speed or power value /
When the rotational speed and the hydraulic pressure / rotational speed when the mixer was hydraulically driven were measured, the axial torque increased once after the kneading started, and decreased as the fresh concrete approached the kneading state, and When kneaded, it tends to be in a substantially stable state, and the lower the axial torque at this time, the higher the moisture content of the green concrete tends to be.

(2) Further, as shown in FIG. 4, the relationship between the slump flow value representing the workability of green concrete and the shaft torque of the mixer when the fresh concrete is kneaded is such that the higher the shaft torque, the slump flow value. On the other hand, as shown in FIG. 5, on the other hand, as shown in FIG. 5, the relationship between the funnel time value indicating the workability of fresh concrete and the shaft torque of the mixer when the fresh concrete is kneaded is that the higher the torque, the more the funnel time becomes. The value also tends to increase.

(3) Therefore, a predetermined amount of mortar, gravel and a little less than the predetermined amount of the admixture (primary admixture) is used by using the mortar whose moisture content has been previously measured and the gravel whose surface water amount has been actually measured. ) Is subjected to model kneading in which various amounts of water are kneaded, and the axial torque of the mixer and the slump flow value or funnel time value of the fresh concrete when kneading the fresh concrete produced by the model kneading If the relationship is sought, the workability of the ready-mixed concrete can be grasped from the axial torque when the ready-mixed concrete is mixed.

(4) Further, if the replenishment amount of the admixture required to provide the ready-mixed concrete produced by each of the above model kneading with a predetermined workability is calculated as shown in FIG.
As shown in, it is possible to grasp the axial torque when the fresh concrete is kneaded in each model kneading and the amount of the admixture (secondary admixture) to be replenished to the kneaded fresh concrete.

(5) If the amount of the secondary admixture to be replenished to the ready-mixed fresh concrete can be ascertained in this way, the fluctuation of the surface water amount of gravel and gravel whose predetermined amount of mortar and surface water is unknown In order to have a predetermined workability by measuring the axial torque when kneading fresh concrete produced by kneading with a smaller amount of primary admixture than the predetermined amount so that it can be dealt with, The amount of admixture (secondary admixture) to be added to the green concrete can be calculated.

[0013]

An object of the present invention is to provide ready-mixed concrete with a predetermined workability.

[0014]

In order to achieve the above object, in a quality control apparatus for ready-mixed concrete of the present invention, a predetermined amount of mortar whose moisture content is measured and a predetermined amount of gravel and a predetermined amount whose surface water amount are measured are used. Addition of admixture to the relationship between the axial torque of the mixer and the amount of secondary admixture to be added to the fresh concrete when the fresh concrete produced by kneading a slightly smaller amount of the primary admixture and water with the mixer An admixture replenishment amount data memory stored as amount data, a flow rate adjusting valve provided in the admixture supply system passage to the mixer, a flow meter for detecting the flow rate of the admixture passing through the flow rate adjusting valve, and a raw A shaft torque calculator for determining the shaft torque of a mixer for kneading concrete, and whether or not the shaft torque value signal output from the shaft torque calculator is in a stable state, or A stable state determiner that determines whether or not a predetermined time has elapsed since the shaft torque signal was output, and the admixture replenishment amount data and the axial torque when the calculation start signal is output from the stable state determiner. The admixture replenishment signal is output from the replenishment admixture amount calculator that calculates the amount of the secondary admixture to be replenished to the ready-mixed concrete based on the value signal and outputs the admixture supplement replenishment signal. At this time, a supplementary admixture supply control for adjusting the opening of the flow rate adjusting valve by outputting a flow rate adjusting signal to the flow rate adjusting valve based on the admixture supplementing signal and the flow rate detection signal output from the flow meter. Equipped with vessels.

[0015]

In the quality control device for ready-mixed concrete of the present invention,
The stable state judgment device determines that the shaft torque signal output from the shaft torque calculator is in a stable state, and the admixture replenishment amount stored in the admixture replenishment amount data storage unit by the replenishment admixture amount calculator. The amount of the secondary admixture to be replenished to the fresh concrete is calculated based on the data and the shaft torque signal, and the secondary admixture is supplied to the fresh concrete by operating the flow rate adjusting valve by the supplementary admixture supply controller. Therefore, the workability of ready-mixed concrete becomes appropriate.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of green concrete manufacturing equipment to which an embodiment of the quality control device for green concrete of the present invention is applied. 1 is a mixer, and the mixer 1 is driven by a motor 2 and It is designed to mix concrete.

3 is a gravel storage hopper, 4 is a gravel weighing hopper, the gravel weighing hopper 4 weighs the gravel 5 fed from the gravel storage hopper 3, and supplies the weighed gravel 5 to the mixer 1. It is like this.

6 is a sand storage hopper, and 7 is a sand weighing hopper. The sand weighing hopper 7 weighs the sand 8 fed from the storage hopper 6 and supplies the weighed sand 8 to the mixer 1. It has become.

A cement storage hopper 9 and a cement weighing hopper 10 are provided. The cement weighing hopper 10 weighs the cement 11 fed from the cement storage hopper 9 and supplies the weighed cement 11 to the mixer 1. It is like this.

Reference numeral 12 is a water storage tank, and 13 is a water metering hopper. The water metering hopper 13 measures the water 15 flowing in from the water storage tank 12 through the on-off valve 14, and measures the measured water 15 as described above. It is supplied to the mixer 1.

Reference numeral 20 denotes an admixture storage tank, and the admixture 21 stored in the admixture storage tank 20 is a flow rate adjusting valve 2
It is designed to be supplied to the mixer 1 as the primary admixture 42 or the secondary admixture 43 via 2 and the flow rate of the admixture 21 supplied to the mixer 1 is measured by the flow meter 23. Has become.

Reference numeral 24 is an inverter device, and the inverter device 24 supplies a drive current 25 to the motor 2.

Reference numeral 26 denotes a rotation speed detector, which detects the rotation speed of the mixer 1 and detects the rotation speed detection signal 2
7 is output.

Reference numeral 28 denotes a power meter, which measures the power supplied from the inverter device 24 to the motor 2 and outputs a power value measurement signal 29.

Reference numeral 30 denotes a shaft torque calculator, which calculates the shaft torque of the mixer 1 based on the rotation speed detection signal 27 and the power value measurement signal 29 and outputs a shaft torque signal 31. It is supposed to do.

Reference numeral 32 denotes a stable state determiner. The stable state determiner 32 determines whether or not the signal value of the shaft torque signal 31 output from the shaft torque calculator 30 has been stable for a certain period of time or longer. When the shaft torque signal 31 becomes stable, the calculation start signal 33 is output.

44 is an admixture replenishment amount data storage unit,
The admixture replenishment amount data storage 44 stores the relationship between the axial torque of the mixer 1 when the fresh concrete is kneaded and the replenishment amount of the secondary admixture 43 to be replenished to the fresh concrete (see FIG. 2). It is stored as replenishment amount data 45.

Reference numeral 46 is a replenishment admixture amount computing unit, which is a replenishment admixture amount data storage unit when the stable state judging unit 32 outputs a computation start signal 33. The admixture replenishment amount data 45 stored in 44 is read, and the amount of the secondary admixture 43 to be replenished based on the admixture supplement replenishment amount data 45 and the shaft torque signal 31 output from the shaft torque calculator 30 is determined. Ask, admixture replenishment signal 4
7 is output.

Reference numeral 48 is a supplementary admixture supply controller, and the supplementary admixture supply controller 48 is the supplementary admixture amount calculator 4 described above.
When the admixture replenishment signal 47 is output from 6, the flow rate adjustment signal 49 that opens the flow rate adjustment valve 22 is output to the flow rate adjustment valve 22 to detect the flow rate output from the flow meter 23. After the flow rate corresponding to the admixture supplement signal 47 is measured based on the signal 50 and the admixture supplement signal 47,
A flow rate adjusting signal 49 for closing the flow rate adjusting valve 22 is output to the flow rate adjusting valve 22.

Reference numeral 51 is a workability data storage device. In the workability data storage device 51, the relationship between the axial torque of the mixer 1 and the slump flow value of the fresh concrete when the fresh concrete is kneaded (see FIG. 4). ) And the relationship between the shaft torque of the mixer 1 when the fresh concrete is kneaded and the rot time value of the fresh concrete (see FIG. 5) are stored as workability data 52.

Reference numeral 53 is a workability calculator, and the workability calculator 53 includes the workability data 52 stored in the workability data storage 51 and the shaft torque signal 31 output from the shaft torque calculator 30.
Based on and, the slump flow value and funnel time value of the ready-mixed concrete to be kneaded by the mixer 1 are obtained, and the workability measurement signal 54 is output.

Reference numeral 55 is a workability display device, and the workability display device 55 is a slump flow of fresh concrete mixed by the mixer 1 based on the workability measurement signal 54 output from the workability calculator 53. The value and the funnel time value are displayed.

The operation of this embodiment will be described below.

In the ready-mixed concrete manufacturing facility shown in FIG. 1, when the ready-mixed concrete is manufactured, a predetermined amount of cement 11 stored in the cement storage hopper 9 is weighed by the cement weighing hopper 10, and the sand storage hopper 6 is used. A predetermined amount of sand 8 stored in is measured by a sand weighing hopper 7.

A predetermined amount of water 15 stored in the water storage tank 12 is measured by the water measuring hopper 13, and the water 15
Then, the cement 11 and the sand 8 are put into the mixer 1, and the motor 2 is operated by the inverter device 24 to make the mixer 1
Rotate at high speed to knead mortar.

When the mortar is kneaded by the mixer 1, the gravel 5 stored in the gravel storage hopper 3 is weighed by a predetermined amount by the gravel weighing hopper 4, and the water 15 stored in the water storage tank 12 is weighed. A predetermined amount is measured by the hopper 13, water 15 and gravel 5 are put into the mixer 1, and the admixture 21 stored in the admixture storage tank 20 is also added.
While measuring the flow rate with the flow meter 23, the admixture 2
1 is supplied to the mixer 1 as the primary admixture 42 so that the integrated flow rate thereof is slightly smaller than the predetermined amount for mortar, and the motor 2 is operated by the inverter device 24 to rotate the mixer 1 at a medium speed.

When the motor 2 is operated, the rotation speed of the mixer 1 is detected by the rotation speed detector 26, and the rotation speed detector 2 is detected.
The rotation speed detection signal 27 is output from 6 and the electric power supplied from the inverter device 24 to the motor 2 is measured by the power meter 28, and the power value measurement signal 29 is output from the power meter 28.

The shaft torque calculator 30 obtains the shaft torque of the mixer 1 based on the rotation speed detection signal 27 and the power value measurement signal 29, and outputs a shaft torque signal 31.

At this time, as shown in FIG. 3, the time-dependent change of the axial torque of the mixer 1 increases once after the start of the kneading of fresh concrete, and decreases as the mortar approaches the kneading state, and when the mortar kneads. It tends to be in a substantially stable state.

In this way, the fresh concrete produced by kneading the water 15, the gravel 5, and the primary admixture 42 into the mortar is in a kneaded state, and the signal value of the shaft torque signal 31 is constant. When the stable state is reached for a time or longer, the stable state determiner 32 outputs the calculation start signal 33.

When the calculation start signal 33 is output, the admixture replenishment amount calculator 46 causes the admixture replenishment amount data memory 44 to store the admixture replenishment amount data 45 (see FIG. 2) and the shaft torque. Based on the signal 31, the amount of the secondary admixture 43 to be replenished to the ready-mixed concrete currently mixed by the mixer 1 is obtained, and the admixture replenishment signal 47 is output.

When the admixture replenishment signal 47 is output, the replenishment admixture supply controller 48 outputs a flow rate adjusting signal 49 to the flow rate adjusting valve 22 to open the flow rate adjusting valve 22, and the admixture storage tank. The admixture 21 stored in 20 is supplied to the mixer 1 as a secondary admixture 43 via a flow meter 23.

At this time, the flow meter 23 measures the flow rate of the secondary admixture 43 passing through the flow meter 23 to obtain the flow rate detection signal 5
Outputs 0.

Further, the replenishment admixture supply controller 48 measures the flow rate corresponding to the admixture replenishment signal 47 based on the flow rate detection signal 50 and the admixture replenishment signal 47, and then sends the flow rate adjustment signal 49. Output to the adjusting valve 22 to close the flow rate adjusting valve 22.

When the secondary admixture 43 is further kneaded into the green concrete in this way, the workability of the green concrete is adjusted to a predetermined value.

As described above, in this embodiment, by mixing the predetermined amount of mortar and water 15, the predetermined amount of gravel 5 of which surface water amount is unknown and the primary admixture 42 of not more than the predetermined amount by the mixer 1. A secondary admixture 43 for grasping the axial torque of the mixer 1 at the time of kneading the generated fresh concrete and for providing a predetermined workability.
Is further replenished to the fresh concrete, so that the fresh concrete can be provided with a predetermined workability without being influenced by the surface water ratio of the gravel 5.

When the mixer 1 is in operation, the workability calculator 53 mixes the workability data 52 stored in the workability data storage 51 and the shaft torque signal 31 by the mixer 1 based on the workability data 52. The slump flow value and the funnel time value of the ready-mixed concrete are obtained, and the workability measurement signal 54 is output.

Further, the workability display device 55 displays the slump flow value and funnel time value of the green concrete mixed by the mixer 1 based on the workability measurement signal 54.

The quality control device for ready-mixed concrete according to the present invention is not limited to the above-mentioned embodiment, and it is determined whether or not a predetermined time has passed since the shaft torque signal was output from the stable state determiner. As a structure for determining whether the shaft torque has stabilized with the passage of time, it is changed to an electric power value as a value for grasping the shaft torque of the mixer and the current value or hydraulic pressure is used as a parameter. Needless to say, various changes can be made without departing from the scope of the invention.

[0051]

As described above, according to the quality control device for ready-mixed concrete of the present invention, the amount of the secondary admixture to be replenished in the ready-mixed concrete is determined based on the shaft torque of the mixer and the admixture replenishment amount data. Since the secondary admixture is automatically supplied to the ready-mixed concrete, the workability of the ready-mixed concrete can be set to an appropriate value, and labor saving can be achieved in the production process of the ready-mixed concrete.
That is, the excellent effect can be achieved.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an example of ready-mixed concrete manufacturing equipment to which an embodiment of a quality control device for ready-mixed concrete of the present invention is applied.

FIG. 2 is a graph showing the relationship between the axial torque of the mixer when kneading the fresh concrete and the amount of the secondary admixture to be added to the fresh concrete.

FIG. 3 is a graph showing an example of a change over time in the axial torque of the mixer when producing ready-mixed concrete with the facility for producing ready-mixed concrete shown in FIG.

FIG. 4 is a graph showing the relationship between the shaft torque of the mixer and the slump flow value of green concrete when the green concrete is kneaded.

FIG. 5 is a graph showing a relationship between a shaft torque of a mixer and a funnel time value of fresh concrete when the fresh concrete is kneaded.

FIG. 6 is a graph showing the change over time of the axial torque of the mixer during mixing of ready-mixed concrete.

[Explanation of symbols]

 1 Mixer 5 Gravel 15 Water 22 Flow Control Valve 23 Flowmeter 30 Axial Torque Calculator 31 Axial Torque Signal 32 Stable State Judge 33 Calculation Start Signal 42 Primary Admixture 43 Secondary Admixture 44 Admixture Replenishment Amount Data Storage 45 Admixture Replenishment replenishment amount data 46 Replenishment admixture amount calculator 47 Admixture replenishment signal 48 Replenishment admixture supply control device 49 Flow rate adjustment signal 50 Flow rate detection signal

Front page continuation (72) Inventor Shin Tamura 3174 Showa-cho, Kanazawa-ku, Yokohama, Kanagawa Ishikawajima Construction Machinery Co., Ltd. (72) Inventor Hiroaki Masuda 3174 Showa-cho, Kanazawa-ku, Yokohama, Kanagawa Ishikawajima Construction Machinery In-house Co., Ltd. (72) Inventor Atsuhiko Fujisawa 3174 Showa-machi, Kanazawa-ku, Yokohama-shi, Kanagawa Ishikawajima Construction Machinery Co., Ltd.

Claims (1)

[Claims] 1. A raw concrete produced by kneading a predetermined amount of mortar whose moisture content is measured, a predetermined amount of gravel whose surface water amount is measured, a primary admixture slightly less than the predetermined amount, and water with a mixer. An admixture replenishment amount data storage device that stores the relationship between the mixer axial torque when kneading and the amount of secondary admixture that should be replenished to ready-mixed concrete as admixture replenishment amount data, and an admixture supply line to the mixer. , A flow meter for detecting the flow rate of an admixture passing through the flow rate adjusting valve, a shaft torque calculator for obtaining the shaft torque of a mixer for kneading fresh concrete, and the shaft torque calculator A stable state determiner for determining whether the output shaft torque value signal is in a stable state, or for determining whether a predetermined time has elapsed from the beginning of the output of the axial torque signal, Based on the admixture replenishment amount data and the shaft torque value signal, when the calculation start signal is output from the stable state determiner, the amount of the secondary admixture to be replenished to the fresh concrete is obtained, and the admixture replenishment signal is obtained. The replenishment admixture amount calculator for outputting and the flow rate based on the admixture supplement replenishment signal and the flow rate detection signal output from the flow meter when the replenishment admixture amount calculator outputs the admixture supplement replenishment signal. A quality control device for ready-mixed concrete, comprising: a replenishment admixture supply controller that outputs a flow rate adjustment signal to the adjustment valve to adjust the opening of the flow rate adjustment valve.