JP4469547B2 - Ready-mixed concrete manufacturing method and manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for producing ready-mixed concrete.
[0002]
[Prior art]
The quality control of ready-mixed concrete is different from industrial materials such as cement and admixture among raw materials, and it is important to suppress the influence of natural aggregates with large quality fluctuations such as particle size and moisture content and to supply stably It becomes.
In particular, quality fluctuations such as aggregate particle size and moisture content have an extremely large effect on workability and durability, including the compressive strength of ready-mixed concrete.
[0003]
Conventionally, as an apparatus and a method for stably supplying ready mixed concrete while suppressing quality fluctuation, those relating to surface water measurement of fine aggregates (JP 2000-9722, JP 2001-170922, JP 11-320543, JP 6-285841, JP-A-8-90549, JP-A-8-39536, JP-A-5-337929, JP-A-5-337929, JP-A-5-208415, JP-A-5-208414) and related to the stable supply of fine aggregate (Japanese Patent Laid-Open No. 10-323821, Japanese Patent Laid-Open No. 9-155850, etc.), which are managed by mixing power and rotational speed (Japanese Patent Laid-Open No. 2001-227614, Japanese Patent Laid-Open No. 11-268028, Japanese Patent Laid-Open No. 8-332626, Japanese Patent Laid-Open No. 8-332625, JP-A-8-47920, JP-A-7-256628, JP-A-7-16829, Rights 7-16828, JP-A 7-16827, JP-A-6-66709), or it relates to metering of concrete material (JP-A 8-332624, JP-A 8-183021) and the like are known.
[0004]
[Problems to be solved by the invention]
However, the fresh properties of ready-mixed concrete are greatly influenced not only by the water content of the concrete but also by the amount of admixture such as a water reducing agent. Therefore, in the method of accurately measuring the water content of concrete and the method of accurately measuring the fluidity of concrete, it is possible to stably control the fresh property of each batch even if individual measurement accuracy is improved. Can not.
[0005]
Then, this invention makes it a subject to supply more stably the ready mixed concrete of favorable fresh property, when supplying ready mixed concrete for every batch.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention is a method for producing ready-mixed concrete in which cement, aggregate, kneaded water, AE auxiliary agent and admixture are weighed and kneaded for each batch. The characteristic is that the amount of air, unit water amount and fluidity index of ready-mixed concrete after kneading are measured for each batch, and from the measurement results of air amount, unit water amount and fluidity index, the amount of AE auxiliary agent and the amount of water kneaded in the next batch and water reducing agent amount out calculation, AE aid of the following batch is fed back, so as to adjust the kneading water and admixture weight, and in the calculation of the kneading water, if you change the AE aid amount The measurement result of the unit water amount is corrected based on the air amount error after the change of the AE auxiliary agent amount, and the kneading water amount of the next batch is calculated from the corrected value of the unit water amount .
[0007]
Also, the present invention is the cement has been made aggregate, mixing water, a metering and kneading AE auxiliaries and water reducing agent As a method for producing ready-mixed concrete to carry out for each batch, its features, kneading air quantity of ready-mix concrete after the unit water and flow index was measured every batch, air quantity, unit water and AE aid of subsequent batch from the measurement results of the fluidity index, kneading water and water reducing agent amount Is calculated and fed back to adjust the amount of AE auxiliary, the amount of kneading water and the amount of water reducing agent in the next batch , and when the amount of water reducing agent is changed in the calculation of the amount of water reducing agent, the amount of the AE auxiliary is changed. When the measurement result of the fluidity index is corrected based on the air amount error after the change of the agent amount, and the kneading water amount is changed, the fluidity index is changed based on the unit water amount error after the change of the kneading water amount. Fixed measurements is to calculate the water-reducing agent of the next batch from the correction values of the flowable index.
[0008]
The present invention is also characterized in that, in the method for producing ready-mixed concrete, the fluidity index is a flow time in a hopper for temporary storage of ready-mixed concrete.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a method for producing ready-mixed concrete (hereinafter also simply referred to as “concrete”) and an apparatus for producing the same according to the present invention will be described below in detail with reference to the drawings.
[0012]
FIG. 1 is a schematic view showing a concrete manufacturing apparatus according to the present invention.
Here, the manufacturing apparatus 1 includes a coarse aggregate storage tank 3 for storing coarse aggregate, a fine aggregate storage tank 4 for storing fine aggregate, a cement storage tank 5 for storing cement, A kneading water storage tank 6 for storing the kneading water, an AE auxiliary agent storage tank 7 for storing the AE auxiliary agent, and a water reducing agent storage tank 8 for storing the water reducing agent are provided.
Further, downstream thereof, each cutting device (not shown) for cutting out the concrete raw material from each storage tank, as well as a coarse aggregate measuring tank 13 and a fine aggregate measuring tank 14 for measuring the cutting amount. A cement metering tank 15, a kneading water metering tank 16, an AE auxiliary metering tank 17, and a water reducing agent metering tank 18 are provided.
Each cutting-out device is operated by a signal from the control unit 50 to be described later, and is configured to supply a predetermined amount of raw material requested to each measuring tank.
[0013]
Further, a concrete mixer 9 provided with a kneading motor 19 is provided downstream of each of the measuring tanks 13 to 18 in order to prepare concrete by kneading each measured concrete raw material. A hopper 2 for temporarily storing the prepared concrete is provided downstream of the concrete mixer 9.
[0014]
The hopper 2 is for temporarily storing the prepared concrete before loading it on the truck agitating vehicle. At the lower end, a rubber gate 28 serving as an opening, and a pinch valve 29 for opening and closing the rubber gate 28 are provided. , And a piston rod 25 for adjusting the opening degree of the pinch valve 29.
The piston rod 25 is provided with a laser position check device (not shown) for checking the expansion and contraction of the piston rod 25, that is, the opening degree of the pinch valve 29.
[0015]
Furthermore, the hopper 2 is suspended from a load cell 21 for measuring the weight of the stored concrete, and a plurality of distances for measuring the height of the stored concrete are provided on the upper surface 2a of the hopper. A sensor 22 is provided. The inclined surface 2b of the hopper is provided with a moisture meter 24 for measuring the water content of concrete.
[0016]
As the moisture meter 24, for example, a reflective neutron moisture meter can be preferably used. FIG. 2 shows the display value of the moisture meter when the water content of concrete having a known water content is measured using a reflective neutron moisture meter. As shown in FIG. 2, the measurement result of the reflective neutron moisture meter has a very good correlation with the water content of the concrete, and the reflective neutron moisture meter is used as a means for measuring the water content. It can be seen that measurement results with sufficient accuracy can be obtained.
[0017]
On the other hand, as the distance sensor 22, an ultrasonic distance sensor can be suitably used.
[0018]
As shown in FIG. 1, the measurement data of each of the measuring tanks 13 to 18, the concrete mixer 9, the load cell 21, the distance sensor 22, the moisture meter 24, and the position check device are all transmitted to the control unit 50 and processed. It is comprised so that. The data or the calculation result transmitted to the control unit 50 can be recorded in the data recording device 51 as necessary.
[0019]
Then, the controller 50 determines the amount of concrete air, the amount of water contained in the concrete per unit volume (hereinafter referred to as the unit water amount), and the fluidity index from each measurement data input by the processing procedure as shown in FIG. As one form, a function of calculating the flow time of concrete per unit volume is provided.
Further, the control unit 50 has a function of calculating correction values for the kneading water amount, the water reducing agent amount, and the AE auxiliary agent amount of the next batch based on these calculated values.
[0020]
As a specific calculation procedure of the unit water amount of concrete in the control unit 50, the following procedure can be exemplified.
(1a) The volume of the concrete is calculated based on the hopper shape inputted in advance by the data sent from the distance sensor.
(2a) The weight of concrete is calculated from the data sent from the load cell.
(3a) The unit volume mass of the concrete is calculated from the volume and weight of the concrete obtained in the above (1a) and (2a).
(4a) The unit water amount of concrete is calculated from the data sent from the moisture meter and the unit volume mass of the concrete.
[0021]
Moreover, the following procedures can be illustrated as a concrete calculation procedure of the air quantity of concrete in the control part 50. FIG.
(1b) The unit volume mass is calculated from the weight of each concrete raw material sent from the load cell provided in each measuring tank and the concrete volume calculated in (1a).
(2b) When the unit volume mass of the concrete calculated in the above (3a) is M1, and the unit volume mass calculated in (1b) is M2, the air amount (%) of the concrete can be obtained by the following equation. .
Air amount (%) = [(M1-M2) / M1] × 100
[0022]
Furthermore, as a calculation procedure of the concrete flow-down time per unit volume in the control unit 50, the following procedure can be exemplified.
(1c) The concrete flow time is calculated from signals from the position check device and the distance sensor.
(2c) Then, the concrete flow time per unit volume can be calculated by dividing the concrete flow time by the concrete volume calculated in (1a).
[0023]
Here, the time from the start of discharging when loading concrete stored temporarily in the hopper to the agitate vehicle until the completion of total discharge, and the sample of the concrete loaded in the agitate vehicle are collected and based on JIS standards The relationship with the measured “slump” is shown in FIG. As shown in FIG. 4, “flowing time” and “slump” have a very good correlation. By adopting the flow time of concrete in the hopper as a fluidity index, It can be seen that the fresh properties can be grasped.
[0024]
As described above, in the present embodiment, the unit water amount measuring means is composed of the load cell 21, the distance sensor 22, and the moisture meter 24, and the air amount measuring means is each measuring tank 13-18 for measuring the weight of each concrete raw material. The distance sensor 22 and the load cell 21 are included, and the flow time measuring means is composed of the distance sensor 22 and a position check device. And it is comprised so that the measurement data of such a component apparatus can be input into the control part 50 which is a control means, and it can calculate as each unit water amount, air amount, and flow-down time.
In the present embodiment, the case where the flow-down time obtained as described above is converted into a slump according to FIG. 4 will be described.
[0025]
Moreover, in this embodiment, the control part 50 calculates the correction value of the next batch compounding quantity based on said calculation result by the procedure as shown, for example in FIGS. 5-7, and feeds back a calculation result to each measuring tank. It also functions as such a control means. Below, the function which calculates the correction value of the following batch compounding quantity is demonstrated.
[0026]
The controller 50 corrects the AE auxiliary agent addition amount of the next batch according to the procedure as shown in FIG. That is, an error in the air amount is obtained by comparing the calculated concrete air amount with a preset air amount target value, and converted to a correction amount of the AE auxiliary agent addition amount using a calibration curve as shown in FIG. Then, the AE auxiliary agent addition amount is corrected by the correction amount, and the correction value is fed back to the AE auxiliary metering tank 17.
[0027]
For example, the cement unit amount is 330 kg / m ³ , the AE auxiliary additive amount is 0.002% of the cement unit amount, the set air amount target value is 4.5%, and the allowable error range is ± If the calculated amount of concrete air is 6.5% when it is 1.0%, the error in the air amount is + 2.0%, which is out of the error range. Correction is required. At this time, the correction value of the AE auxiliary agent amount of the next batch is calculated based on the relationship between the air amount error and the AE auxiliary agent correction amount as shown in FIG. It can be calculated as 0.001% (relative to the cement unit amount) by converting the correction amount to 0.001% and subtracting 0.001% from the added amount of AE auxiliary 0.002%.
[0028]
Further, the control unit 50 corrects the unit water amount of the next batch according to the procedure as shown in FIG. That is, the calculated unit water amount of the concrete is compared with a preset unit water amount target value to obtain a unit water amount error, a correction value of the kneading water amount is calculated according to the degree of the error, and fed back to the next batch.
Here, the unit water amount at the time of blending is calculated as the total amount of the kneaded water, the admixture and the surface water of the fine aggregate, but the error from the unit water amount target value is mainly the surface water amount of the fine aggregate. Often caused by fluctuations. Therefore, when the kneading water amount is corrected, it is preferable to change the set value of the surface water ratio of the fine aggregate as shown in FIG. Changing the surface water ratio setting value of fine aggregate not only corrects the amount of kneading water but also corrects the fine aggregate unit amount to a true value, so that the composition of each batch can be grasped more accurately. Is possible.
[0029]
For example, when the fine aggregate unit amount is 865 kg / m ³ , the surface water ratio setting value is 4.0%, the unit water amount target value is 165 kg / m ³ , and the allowable error range is ± 3 kg / m ³ , If the calculated unit water amount of the concrete is 156 kg / m ³ , the error of the unit water amount −9 kg / m ³ falls outside the error range, and thus the surface water ratio needs to be corrected.
Then, assuming that such an error in the unit water amount is caused by “fine aggregate unit amount × fine aggregate surface water ratio”, the unit water amount error (−9 kg / m ³ ) is reduced to the fine aggregate unit amount (865 kg / m ³ ). ³ ) and by correcting the surface water ratio set value (4.0%) by the value obtained (−1.0%), the correction value (3. 0%).
[0030]
When the air amount calculation result is out of the error range and the AE auxiliary agent amount of the next batch is changed, as shown in FIG. 6, the unit water amount calculation result is corrected in advance with the air amount error. It is preferable to calculate a unit water amount error and a surface water ratio correction value using the correction value after obtaining the correction value of the water amount.
[0031]
Further, the control unit 50 corrects the amount of water reducing agent in the next batch according to the procedure shown in FIG. That is, the slump error is obtained by comparing the calculated slump with a preset slump target value, converted to a correction amount of the water reducing agent amount using a calibration curve as shown in FIG. The correction value of the agent is calculated, and the correction value is fed back to the water reducing agent measuring tank 18.
[0032]
For example, when the cement unit amount is 330 kg / m ³ , the water reducing agent amount is 1.0% of the cement unit amount, the set slump target value is 18 cm, and the allowable error range is ± 1.5 cm. If the slump obtained by converting the measured value is 22 cm, the error +4 cm is out of the error range, so the amount of the water reducing agent needs to be corrected. At this time, the correction value of the water reducing agent amount in the next batch is based on the relational expression between the water reducing agent amount and the slump as shown in FIG. 9, and the error (+4 cm) between the obtained slump and the slump target value is corrected with the water reducing agent. It can be calculated as 0.8% by converting the amount to 0.2% and subtracting from 1.0%.
[0033]
When the air amount calculation result is out of the error range and the AE auxiliary agent amount of the next batch is changed, the air amount of the next batch is also changed. Therefore, in such a case, as shown in FIG. 7, it is preferable to correct the slump by the air amount error and obtain the slump error using the corrected value. For example, a calibration curve as shown in FIG. 10 is used for the relationship between the air amount error and the slump correction amount.
[0034]
For example, as described above, when the slump calculation result is 22 cm and the air amount error is + 2.0%, based on the relational expression between the air amount error and the slump correction amount as shown in FIG. The slump correction amount is determined to be 5 cm, and the slump correction value is calculated to be 17 cm by subtracting the slump correction amount of 5 cm from the slump calculation result of 22 cm. In this case, the slump correction value is within the slump error range, and the amount of water reducing agent is not corrected.
[0035]
When the unit water amount calculation result is outside the unit water amount error range and the unit water amount of the next batch is corrected, as shown in FIG. 7, the slump is corrected by the unit water amount error, and the corrected value is used. It is preferable to determine the slump error. For example, a calibration curve as shown in FIG. 11 is used for the relationship between the unit water amount error and the slump correction amount.
[0036]
For example, as described above, when the amount of the water reducing agent is 1.0% with respect to the cement unit amount, the slump calculation result is 22 cm, and the error of the unit water amount is −9 kg / m ³ , FIG. Based on the relational expression between the unit water amount error and the slump correction amount as shown, the slump correction amount is obtained as 6 cm, and the slump correction value is calculated as 28 cm. In this case, since the error of the slump is +10 cm, the water reducing agent correction amount is determined to be 0.5% based on the relational expression between the slump error and the water reducing agent correction amount shown in FIG. Subtract from 1.0% to 0.5% (based on cement unit).
[0037]
Next, a concrete manufacturing method when the concrete manufacturing apparatus having such a configuration is used will be described.
[0038]
First, a batch of a predetermined amount of concrete raw material is supplied from each of the concrete raw material storage tanks 3 to 8 to each of the measuring tanks 13 to 18. Next, each concrete raw material is transferred to the concrete mixer 9 and mixed so as to be homogeneous, whereby concrete is prepared. The concrete is temporarily stored in the hopper 2 before being loaded onto the truck agitator vehicle.
[0039]
In the hopper 2, after measuring the weight, volume, moisture content, etc. of the concrete as described above, the pinch valve 29 is opened at a constant opening by a position check device, and the concrete is supplied to the truck agitating vehicle. At this time, the distance sensor 22 installed in the hopper upper part 2a measures the time from the start of concrete discharge until it is completely discharged.
[0040]
And in the control part 50, the unit water quantity of concrete, the flow time per unit volume, and the air quantity are calculated by the method as described above, and based on these calculation results, the composition of the concrete raw material of the next batch is determined, The new batch will prepare the next batch of concrete.
[0041]
As described above, according to the manufacturing method and manufacturing apparatus of the present embodiment, the fresh property of the concrete is obtained by calculating the “unit water amount”, “flow time per unit volume”, and “air amount” of the concrete for each batch. As the result is a more accurate understanding and a combination of these calculation results to correct the amount of concrete blended in the next batch, even if the quality of the concrete raw material fluctuates, the concrete with good fresh properties is always stable. Can be supplied.
[0042]
In addition, according to the said embodiment, when correcting the fine aggregate surface water rate, the measurement result of the air amount was considered in addition to the measured unit water amount, but the present invention is not limited to this. Absent. Therefore, it is also possible to correct the fine aggregate surface water ratio based only on the measured value of the unit water amount. Further, the correction target may be the amount of kneading water instead of the fine aggregate surface water ratio.
[0043]
Furthermore, according to the embodiment, when correcting the amount of water reducing agent, the measured slump is used as a reference, the slump is corrected based on the measurement result of the air amount or unit water amount, and the water reducing agent is corrected using the corrected slump. Although the correction value is calculated, the present invention is not limited to this. Therefore, it is also possible to correct the amount of water reducing agent based only on the slump measurement value.
[0044]
Further, regarding the fresh properties of concrete, physical properties other than the unit water amount, the flow time per unit volume, and the air amount may be measured, and the blending of the next batch may be corrected in consideration of the measured values.
[0045]
【The invention's effect】
As described above, according to the ready mixed concrete manufacturing method and manufacturing apparatus according to the present invention, it is possible to accurately grasp the concrete fresh property for each batch and perform appropriate feedback control. It becomes possible to supply concrete stably.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a ready mixed concrete manufacturing apparatus according to the present invention.
FIG. 2 is a graph showing a relationship between a moisture meter measurement result and a unit water amount.
FIG. 3 is a flowchart showing a calculation procedure in a control unit.
FIG. 4 is a graph showing the relationship between hopper flow time and slump.
FIG. 5 is a flowchart showing an example of a calculation procedure of an AE auxiliary agent correction value in a calculation unit.
FIG. 6 is a flowchart showing an example of a calculation procedure of the fine aggregate surface water ratio in the calculation unit.
FIG. 7 is a flowchart showing an example of a calculation procedure of a water reducing agent correction value in a calculation unit.
FIG. 8 is a graph showing an example of a relationship between an air amount error and an AE auxiliary agent correction amount.
FIG. 9 is a graph showing an example of a relationship between a slump error and a water reducing agent correction amount.
FIG. 10 is a graph showing an example of a relationship between an air amount error and a slump correction amount.
FIG. 11 is a graph showing an example of a relationship between a unit water amount error and a slump correction amount.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... This manufacturing apparatus, 2 ... Hopper, 3 ... Coarse aggregate storage tank, 4 ... Fine aggregate storage tank,
5 ... Cement storage tank, 6 ... Kneading water storage tank, 7 ... AE auxiliary storage tank,
8 ... Water reducing agent storage tank, 9 ... Concrete mixer, 13 ... Coarse aggregate measuring tank,
14 ... Fine aggregate measuring tank, 15 ... Cement measuring tank, 16 ... Kneading water measuring tank,
17 ... AE auxiliary measuring tank, 18 ... Water reducing agent measuring tank, 21 ... Load cell,
22 ... Distance sensor, 24 ... Moisture meter, 25 ... Piston rod, 28 ... Rubber gate 29 ... Pinch valve, 50 ... Control unit

Claims (4)

  In a method for producing ready-mixed concrete in which cement, aggregate, kneaded water, AE auxiliary agent and water reducing agent are measured and kneaded for each batch, the amount of air, unit water amount and fluidity index of the ready-mixed concrete after kneading are set to 1. Measure for each batch, calculate the amount of AE assistant, kneading water and water reducing agent in the next batch from the measurement results of air quantity, unit water quantity and fluidity index, and feed back the amount of AE assistant and kneading water quantity in the next batch In the calculation of the kneading water amount, when the amount of the AE auxiliary agent is changed, the measurement result of the unit water amount is calculated based on the air amount error after the change of the AE auxiliary amount. A method for producing ready-mixed concrete, comprising correcting and calculating the kneaded water amount of the next batch from the corrected value of the unit water amount.   In a method for producing ready-mixed concrete in which cement, aggregate, kneaded water, AE auxiliary agent and water reducing agent are measured and kneaded for each batch, the amount of air, unit water amount and fluidity index of the ready-mixed concrete after kneading are set to 1. Measure for each batch, calculate the amount of AE assistant, kneading water and water reducing agent in the next batch from the measurement results of air quantity, unit water quantity and fluidity index, and feed back the amount of AE assistant and kneading water quantity in the next batch In the calculation of the water reducing agent amount, when the amount of the AE auxiliary agent is changed, the fluidity index is calculated based on the air amount error after the change of the amount of the AE auxiliary agent. When the measurement result is corrected and the kneading water amount is changed, the measurement result of the fluidity index is corrected based on the unit water amount error after the change of the kneading water amount, and the previous value from the corrected value of the fluidity index is corrected. Method for producing ready-mixed concrete and calculates a water reducing agent amount for the next batch. The flowable indicator method for producing a ready-mixed concrete according to claim 1 or 2, characterized in that the flow time of the temporary storage for the hopper of ready-mix concrete. The method for producing ready-mixed concrete according to any one of claims 1 to 3, wherein the unit water amount of the ready-mixed concrete after kneading is measured using a neutron moisture meter.

Images