KR102519893B1 - Ready mixed concrete manufacturing method - Google Patents

Abstract

(Problem) The present invention is to manufacture raw concrete as ordered without unnecessary test mixing.
(Means of solution) Divide the production of raw concrete into two times, compare the slump and slump flow values for each time to determine suitability, and in the next time of the unsuitable time, increase or decrease the amount of the admixture considering the previous time, and then Estimated strength is obtained by obtaining the ratio of the amount of cement and unit water in raw concrete, and compared with the required strength, the amount of moisture is increased or decreased, and the raw concrete produced by multiple times is mixed in the same mixer truck.
(Effects) Since there is no test mixing, raw concrete in every round is not wasted, and high-quality raw concrete can be manufactured on demand because the entire quantity is produced while finely adjusting by increasing the number of divisions.

Description

Raw concrete manufacturing method {READY MIXED CONCRETE MANUFACTURING METHOD}

The present invention relates to a technology for shipping ready mixed concrete as ordered.

As the biggest request of the ordering party for raw concrete, it is assumed that it is manufactured according to the order of the ordering party (with the mixture of materials), and in particular, the following two At least one of the conditions is met.

(1) That the manufactured raw concrete meets the prescribed strength and durability when reaching the prescribed age, and that this is guaranteed.

(2) The fresh property at the time of transporting the manufactured raw concrete to a predetermined place by a mixer truck should ensure workability that is easy to pour.

Regarding the concrete strength and durability after hardening in (1) above, the present applicant, based on the amount of water and the amount of cement contained in the raw concrete produced, based on the performance of the raw concrete factory, kneaded without a predetermined age ( A method for guaranteeing strength and durability immediately after cleaning, that is, a method for stably shipping high-quality fresh concrete as ordered by suppressing with a high probability the possibility of nonconformity occurring after shipment from the raw concrete manufacturing plant. 1 (Japanese Patent No. 5718886).

That is, the method proposed in Patent Literature 1 is based on cement, aggregate, and surface yield of aggregate mixed according to the order when producing raw concrete, corrected based on the dynamic load of water and admixture The weight is measured, these are kneaded, and the unit water quantity of the raw concrete after kneading is measured, and the ratio between the amount of cement and the unit water quantity is obtained from the measured value to obtain the estimated strength, as well as the lowest and highest values of this estimated strength. The range of values is obtained, whether or not the unit quantity is less than the recommended value, whether the ratio between the amount of cement and the unit quantity is less than or equal to a predetermined ratio, and the lowest value in the range of the lowest and highest values of the estimated strength is the required strength and the estimated strength Shipment is determined only when all conditions are met, whether or not the probability of occurrence of the lowest value of is greater than or equal to 95%.

In addition, mainly regarding the pouring workability and workability of the green concrete in the above (2), the present applicant, in Patent Document 2 (Japanese Unexamined Patent Publication No. 2020-71134), the composition and mixing of raw concrete, the load of the kneading device, etc. A method of calculating a highly reliable slump and slump flow estimate by measuring fluidity by excluding disturbance factors was proposed.

That is, the method proposed in Patent Document 2 is a hollow truncated cone with an upper and lower surface open to estimate the slump and slump flow values of raw concrete, and the upper surface has a large diameter and the lower surface has a large diameter. After kneading and before shipment, raw concrete is charged into the measuring container arranged to have a small diameter, and the discharge time and discharge speed of the raw concrete discharged from the measuring container are measured. The average shear deformation of a plurality of parts of the circumferential edge in the central predetermined diameter part of the top surface of the pile of raw concrete as viewed from the top surface, and the average shear deformation of the plurality of parts of the circumferential edge in the large diameter part larger than the central predetermined diameter part The average shear strain and the maximum volume change, which is the maximum value of the discharge volume within the discharge time of the raw concrete, are continuously measured and calculated within the discharge time, and based on these measurements, the estimated value of the slump and slump flow is calculated.

By using the methods of Patent Literatures 1 and 2, the quality of raw concrete is drastically improved compared to before, and the requirements of (1) and (2) above are satisfied and guaranteed, respectively, than before, but the strength of the ordered (1) The current condition is that the quality of shipped raw concrete still has deviations at the casting site because it has not yet met 100% of the requirements for performance, durability, and (2) workability.

In addition, in order to meet the request of the owner, it is possible to consider repeating so-called trial mixing several times by adjusting water or admixture, but raw concrete that has become unsuitable due to trial mixing cannot be shipped, so it will be discarded. There was no choice but to lose materials or equipment operation rate or time for test mixing.

: Japanese Patent No. 5718886 : Japanese Unexamined Patent Publication No. 2020-71134

The problem to be solved by the present invention is that the ordered requirements for (1) strength and durability and (2) workability are not met up to 100%, so there is still a deviation in the quality of shipped raw concrete at the casting site. In addition, if test mixing is performed to improve the quality of raw concrete to be shipped, loss of material, facility operation rate, or time for test mixing occurs.

In order to solve the above problems, the present invention divides the production of raw concrete into at least two times, calculates the division amount by dividing all the concrete materials by the number of times of production, and calculates the total amount of the concrete material ordered to be the division amount for each time. Each dynamic load divided equally at least twice is measured , and then kneaded, and estimated values of slump and slump flow are calculated for the raw concrete after kneading, and the required slump and slump flow values are compared to the required admixture. / Adjust the amount if unnecessary or necessary, continue to find the estimated strength of raw concrete, determine whether or not this estimated strength is an appropriate value, and adjust the amount of moisture in consideration of the previous time at the next time of the unsuitable time. The raw concrete produced by the above was mixed in the same mixer truck.

Basically, the production of raw concrete is to achieve the ordered (estimated) strength, slump, and slump flow values, but due to weather, time of day, and various other factors, including errors, estimated strength is required from a certain level. do not approach the strength of the Therefore, according to the present invention, even if the production amount (order) of raw concrete is small, for example, it is divided into at least two times, but in the case of, for example, two times without test mixing, the first time is always produced as ordered, and then the second time ( In the final round), the quantity of the second round is corrected in consideration of the error of the first round, so even if the same error as the first round occurs in the second round, the error as a whole is reduced, and it is divided into at least two rounds, but since there is no test mixing, all Since raw concrete is not wasted in each round, and the entire amount is produced while finely adjusting by increasing the number of divisions, high-quality raw concrete can be produced on demand.

[Fig. 1] is a diagram showing the schematic configuration of the raw concrete manufacturing equipment of the present invention.
[Fig. 2] is a diagram showing the manufacturing procedure of the raw concrete of the present invention.
[Fig. 3] is a diagram showing a slump and an estimation sequence of slump flow values.
[Fig. 4] is a diagram showing the order of calculation of estimated strength and necessity/unnecessity of water.
[Figure 5] In the estimation procedure of slump and slump flow value, (a) is a diagram showing the relationship between the flow rate and discharge time when raw concrete is discharged, (b) is the relationship between the maximum flow rate and slump when raw concrete is discharged is a drawing representing
Fig. 6 is a diagram showing the relationship between a measuring vessel and a TOF camera in a slump and slump flow value estimation facility.
[Fig. 7] In the estimation sequence of slump and slump flow values, (a) is a diagram showing the relationship between the shear strain average value and discharge time when the slump value is 10 cm, and (b) is a diagram showing the relationship between the discharge time when the slump value is 15 cm It is a diagram showing the relationship between the average shear strain value and the discharge time.
[Figure 8] In the estimation sequence of slump and slump flow values, (a) is a diagram showing the relationship between the average shear strain value and discharge time when the slump value is 21 cm, and (b) is the maximum average when raw concrete is discharged It is a diagram showing the relationship between shear strain and slump.
[Fig. 9] In the estimation procedure of slump and slump flow value, (a) is a diagram showing the relationship between the volume change of raw concrete and the discharge time, and (b) is a diagram showing the relationship between the maximum volume change of raw concrete and slump it is a drawing
Fig. 10 is a diagram showing the relationship between each factor and the slump in the estimation order of slump and slump flow value.

The present invention aims to satisfy and guarantee at least one of (1) strength and durability and (2) workability of ready mixed concrete. The production of concrete is divided into at least two times, the division amount obtained by dividing all the concrete materials by the number of times of production is calculated, and each dynamic load of the concrete material is measured based on the division amount for each time, and then These are kneaded, estimated values of slump and slump flow are calculated for the raw concrete after kneading, and the required/unnecessary admixture is compared with the required slump and slump flow values. and, if necessary, adjust the amount, continue to find the estimated strength of raw concrete, determine whether this estimated strength is an appropriate value, and increase or decrease the amount of water in consideration of the previous time at the next time of the unsuitable time This was achieved by mixing the raw concrete prepared by the plurality of times with adjustment in the same mixer truck.

In addition, the present invention achieves the above object by dividing the production of raw concrete into at least two times, calculating the division amount by dividing all the concrete materials by the number of times of production, and each dynamic load of the concrete material based on the division amount for each time are measured, these are kneaded, and estimated values of slump and slump flow are calculated for the raw concrete after kneading, and compared with the required slump and slump flow values, in the next time of the inappropriate time, the increase or decrease of the amount of the admixture is adjusted considering the previous time. It can also be achieved by mixing the raw concrete produced multiple times in the same mixer truck by continuously obtaining the estimated strength of the raw concrete after kneading, comparing it to the required strength, and adjusting the increase or decrease in water content.

In addition, in the present invention, for the purpose of both (1) and (2) above, the production of raw concrete is divided into at least two times, the amount of division obtained by dividing all the concrete materials by the number of times of production is calculated, and the division is performed for each time. Measure each dynamic load of the concrete material based on the amount, knead them, check if it is the last time among the number of manufactures, and if it is not the last time, the judgment on the slump and slump flow value is appropriate, and the judgment on the estimated strength is appropriate In this case, the mixer truck is instructed to take out the mixer truck as it is, and when the judgment on the slump and slump flow value is appropriate and the judgment on the estimated strength is unsuitable, the excess and deficiency amount of moisture is calculated and fed back, and the mixer truck is instructed to take out the slump And if the judgment on the slump flow value is inappropriate, the excess or deficiency of the admixture is calculated and fed back. In the case of inappropriateness, the excess or deficiency of the admixture is calculated and fed back, and if the judgment on the estimated strength is inappropriate, the excess or deficiency of the moisture amount is calculated and fed back, and the mixer truck is instructed to withdraw, and in the last time, the excess or deficiency of the admixture fed back to the previous time It can be achieved by performing increase/decrease adjustment taking into consideration the increase/decrease adjustment taking into account the excess/deficiency amount of moisture fed back up to the previous time, taking it out with the same mixer truck as above, and mixing the raw concrete produced multiple times in the same mixer truck.

Further, in the implementation of the above-described manufacturing method, the present invention includes a measuring unit for measuring the ordered cement, aggregate, surface yield of the aggregate, and water and admixture corrected based on the surface yield of the aggregate, respectively; An input unit for instructing and inputting the mixing amount of raw concrete ordered to the management unit, and a cement and aggregate of the mixing ratio input to the input unit. A measuring container arranged so that the upper surface has a large diameter and the lower surface has a small diameter in the shape of a hollow truncated cone with an open upper and lower surface, In this measuring vessel, a TOF (Time of Flight) camera disposed obliquely above the top opening is provided, and the production of raw concrete is divided into at least two times, even if it is a small amount, for example, and it is determined whether or not the current production time is the last time. In addition, (1) obtaining the estimated strength of raw concrete after kneading, determining whether or not this estimated strength is an appropriate value, and adjusting the amount of moisture in consideration of the previous time in the next inappropriate meeting, (2) after kneading A control unit that performs at least (1) among calculating the estimated slump and slump flow values of raw concrete, comparing them with the required slump and slump flow values, and adjusting the amount of the admixture in consideration of the previous time in the next inappropriate session It can be realized by a raw concrete manufacturing facility further equipped with.

(Example)

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The method of the present invention is performed by the raw concrete manufacturing equipment of the present invention shown in Fig. 1, for example. The green concrete manufacturing facility 1 (hereinafter, referred to as facility 1) of the present invention is a facility that takes out light weight of fresh concrete material, kneads, confirms, and ships (discharges with a mixer truck) For example, even if the production amount is small, it is produced by dividing it into multiple (two times in this example), taking into account the value of the estimated strength of the first time, the final value of the slump and slump flow value, and dividing it at the time of producing the next time In order to adjust the amount of moisture and to adjust the amount of admixture, it has the following configuration.

2 is a cement take-out part, 3 is an aggregate take-out part, 4 is a water supply part, and 5 is an admixture take-out part. A cement dynamic load measurement unit 2A, an aggregate dynamic load measurement unit 3A, a surface yield measurement unit 3B, a water dynamic load measurement unit 4A, and an admixture dynamic load measurement unit 5A that measure the mass of are installed.

6 is a kneading device for kneading each material supplied from the cement take-out unit 2, the aggregate take-out unit 3, the water supply unit 4, and the admixture take-out unit 5. In this kneading unit 6, kneading A time measuring unit 6A for measuring time and a kneading frequency measuring unit 6B for measuring the number of times of kneading are respectively provided.

7 denotes a wet batch hopper for taking out raw concrete supplied from the kneading device 6, and a unit quantity measuring unit 7A and a shipment amount measuring unit 7B are installed in the wet batch hopper 7. .

8 is a hollow truncated cone with an upper and lower surface opened between the outlet of the kneading device 6 and the loading opening of the wet batch hopper 7, and is arranged so that the upper surface has a large diameter and the lower surface has a small diameter. It is courage. This measuring container 8 has a shape as shown in FIG. 1 in which the slump cone used in the slump test is reversed, and the upper surface is open and the lower surface is provided with an opening gate controlled to open and close. there is.

Reference numeral 9 denotes a TOF camera (Time of Flight Camera: distance image camera) arranged obliquely above the top surface opening in this measuring container 8. This TOF camera 9 is arranged obliquely above the top surface opening in the measuring container 8 . The TOF camera 9 outputs a photographing (measurement data) signal to a control unit 12 described later, and is controlled by control signals from the control unit 12 to start/stop measurement.

The measuring container 8 and the TOF camera 9 are installed between the kneading device 6 and the wet batch hopper 7 in the case of this embodiment. In addition, the TOF camera 9 is housed in a protective container in order to protect it from cement particles and flying mortar and to perform continuous measurement. This protective container has waterproof, dust-proof and moisture-proof properties, and also has a function of radiating heat emitted from the semiconductor laser.

The above is equipment installed outdoors among equipment 1, and the measurement signal by each measuring unit of the outdoor equipment and the operation instruction signal of each unit are input to and output from the management unit 11 installed as indoor equipment. . In addition, the connection relationship between indoor facilities and outdoor facilities will be described later.

Among the facilities 1, the management unit 11 installed indoors is composed of, for example, a server with a configuration equivalent to a (personal) computer, the CPU and memory provided in the server are the control unit 12, and the hard disk is the data unit ( 13), the keyboard and mouse serve as the input unit 14, and the display (or printer) serves as the output unit 15.

The raw concrete manufacturing method of the present invention is a part of a series of operation programs of production, management, kneading, and determination of whether to ship or not in the facility 1. In the facility 1, the control unit 12 reads the entire program corresponding to the raw concrete manufacturing method from the data unit 13 in the management unit 11, and the control unit 12 reads the following operation unit by activating the so-called program. (12A), the blending instruction unit 12B, and the judgment unit 12C are expressed. The control unit 12 performs various calculations based on various types of input data and formulas read from the data unit 13 or data on inquiries, and controls each unit of the outdoor equipment.

That is, the control unit 12 performs various calculations based on outputs from each of the measurement units 2A, 3A, 3B, 4A, 5A, 6A, 6B, 7A, and 7B and the TOF camera 9, and the determination unit 12C ), the calculation unit 12A outputs the result, and the mixing instruction unit 12B outputs a mixing instruction signal to the cement take-out unit 2, the aggregate take-out unit 3, the water supply unit 4, and the admixture take-out unit 5. ), and a determination unit 12C which mainly determines the suitability of the operation value based on each operation value calculated by the operation unit 12A.

Further, the control unit 12 controls the opening of the opening gate on the lower surface of the measuring container 8 (the same applies to the case where the wet batch hopper 7 also serves). The controller 12 ensures that the gate is always opened according to a certain rule so that the opening speed of the gate and the like do not affect the calculation of the next slump and the estimated value of the slump flow.

Then, the control unit 12 in this embodiment divides the production of raw concrete into at least two times, even if it is a small amount, for example, and calculates the division amount obtained by dividing the ordered mixture amount of cement and aggregate by the number of times of production, and Based on each value measured by the measuring unit, the ratio of the amount of cement and the unit water quantity is calculated to obtain the estimated strength, and at the same time, it is determined whether this estimated strength is an appropriate value or not, and in the next round of the unsuitable round, the amount of moisture considering the previous round is adjusted, and based on the measured values taken by the TOF camera within the discharge time, the estimated value of the slump and slump flow is calculated, and the suitability is determined by comparing with the required slump and slump flow values, and an inappropriate meeting In the next round, adjust the amount of the admixture considering the previous round.

The processing of this control unit 12 will be described below. Fig. 2 is a flowchart showing the processing procedure of the entire method of the present invention in this embodiment. The management unit 11 executes a program that controls the entire facility 1, and inputs an order requested from the input unit 14 under operating conditions of each unit on the outdoor side (Step 1: hereinafter referred to as #1). .

Subsequently, the control unit 12 determines the number of divisions (twice in this embodiment) based on the order (#2), and distributes the divided amount of material to the cement take-out unit 2, the aggregate take-out unit 3, Take it out from the water supply part 4 and the admixture take-out part 5 (#3).

In #3, in this embodiment, the amount of water to be blended is determined based on not only the order but also the surface yield of the aggregate. The correction quantity is determined as follows. The controller 12 measures the coarse aggregate in the aggregate, measures the yield of coarse aggregate in the aggregate, and then the surface yield measuring unit 3B The surface yield of the aggregate is measured, and based on the conditions input from the input unit 14 regarding the current mix in the production of the ordered raw concrete, the data unit 13 is inquired for the quality data of the aggregate, and the estimated strength , and the standard deviation at that time is set.

In #3, when the material is actually taken out, the input unit 14 outputs the determined mixing amount and conditions of the cement, aggregate, water, and admixture to the output unit 15 (here described as a display). , The compounding amount, conditions, etc. are outputted in the output part 15.

When the control unit 12 outputs a withdrawal execution signal from #3, the cement goes to the cement dynamic load measurement unit 2A, the aggregate goes to the aggregate dynamic load measurement unit 3A, and the water (including the above correction) goes to the water dynamic load measurement unit 4A. In this way, the admixture is drawn out to the admixture dynamic load measurement section 5A, respectively.

In this embodiment, prior to material being pulled out to each dynamic load measurement unit (2A, 3A, 4A, 5A) and dynamic load measurement (#4), the measurement accuracy of each measurement unit (2A, 3A, 4A, 5A) is confirmed, , this precision value is output to the control unit 12, and the control unit 12 measures the dynamic load in consideration of the measurement error.

After measuring the dynamic load of each material in #4, the control unit 12 calculates the cement-water ratio (amount of cement/amount of water: the ratio of the amount of cement to the amount of water) using the dynamic load values of cement and water. , the strength before kneading is calculated using the dynamic load value of each material, and this value is temporarily stored in the data section 13. In addition, the strength referred to in the present invention is a general term for compressive strength and bending strength, and each material is charged into the kneading device 6, and kneading is started by the kneading device 6 (#5).

The controller 12 controls the number of times of kneading and the time of kneading from the kneading device 6, outputs the situation to the output unit 15, and monitors and outputs the situation, and when the predetermined number of times and time of kneading have elapsed, Later, in the case of this embodiment, the raw concrete after kneading from the kneading device 6 is discharged to the measuring container 8.

After #5, the control unit 12 estimates the slump and slump flow values described later in detail in the measuring container 8 (#6: subroutine), and determines whether or not this time is the final round of the number of divisions in #2. Check (#7).

If it is not the last in #7 (No in #7), the controller 12 determines whether or not the slump and slump flow values estimated in #6 are appropriate (within the range) (#8), and if appropriate (# OK at 8), the raw concrete is discharged from the measuring container (8) to the wet batch hopper (7).

On the other hand, if it is not titrated in #8 (NG in #8), the control unit 12 sets the excessive or insufficient amount of the admixture as the withdrawal amount of the admixture for the next time (the last time in this embodiment) (as necessary information in #3 In order to do this, the data is fed back to the data unit 13 (#10), and the raw concrete is discharged from the measuring container 8 to the wet batch hopper 7 in the same way as in the case where the process itself is appropriate.

The controller 12 calculates the estimated strength in the wet batch hopper 7 based on the amount of moisture and the amount of cement described in detail later (#9), and checks whether or not this time is the last time of the number of times divided in #2 do (#11).

If it is not the last in #11 (No in #11), the control unit 12 determines whether the value of the strength estimated in #9, that is, the amount of moisture is appropriate (within the range) (#12), and if appropriate ( OK at #12), discharge from the wet batch hopper 7 to the mixer truck (#13), and the round ends.

On the other hand, if it is not appropriate in #12 (NG in #12), the control unit 12 sets the excessive or insufficient amount of water as the water supply amount of the next time (the last time in this embodiment) (as necessary information in #3 For), the data is fed back to the data unit 13 (#14), and the process itself is discharged from the wet batch hopper 7 to the mixer truck (#13) in the same way as in the case of proper processing, and the session ends.

In addition, in #7, when the batch is the final divided batch (Yes in #7), the amount of the admixture is adjusted here in consideration of the excess or deficiency of the admixture up to the previous time (#15), and the process proceeds to #9 , On the other hand, in #11, if the episode is the final episode divided (Yes in #11), the amount of moisture is adjusted here (#16) in consideration of the excess or deficiency of moisture until the previous episode, and the process proceeds to #13 .

The above is an outline of the raw concrete manufacturing method of the present invention using the facility 1 of the present invention. Here, the advantages of dividing and manufacturing one order will be explained. For example, in the case of manufacturing one order at a time, for example, it can be set to a value close to the upper or lower limit of the upper and lower range of the slump and slump flow value, and also, for example, the upper and lower range of the (estimated) intensity value It can be set to a value close to the upper or lower limit.

In the present invention, even values close to the upper or lower limits of the upper and lower limits of the slump, slump flow value, and (estimated) strength value in the case of one order being produced once are not acceptable, and by multiple times of production By dividing and adjusting the admixture and moisture content, which are factors in the value that fluctuates close to the upper or lower limit, in consideration of the previous batch each time, it is possible to get close to the median value of the upper and lower ranges by repeating fine adjustment each time the number of repetitions is repeated. There is an advantage to being

In order to ensure the above-mentioned merit of manufacturing by dividing one order, the calculation process of estimated values of slump and slump flow value in #6 and the calculation process of estimated strength of raw concrete in #9 are important.

(estimation of slump and slump flow value)

The subroutine processing of #6 and #9 will be described below. In FIG. 3, a subroutine for calculating the slump and slump flow values of #6 in FIG. 2 is shown. In the pre-process, that is, in this embodiment, after receiving the raw concrete discharged from the kneading device 6 (described later) with the opening gate on the lower surface of the measuring container 8 closed, the control unit 12 counts a certain amount of time to stand still (Step 1: hereinafter referred to as S1).

The controller 12 receives all of the raw concrete discharged from the previous process in the measuring container 8 and after a certain period of time has elapsed, opens the opening gate installed on the lower surface of the measuring container 8 to remove the raw concrete from the measuring container 8. Raw concrete is discharged (S2). This open gate is designed so that the manner of opening does not affect the estimation of the slump and slump flow values.

The control unit 12 operates the TOF camera 9 at the same time or just before the opening gate on the lower surface of the measuring container 8 is opened (S3). The TOF camera 9 continues to photograph the top surface of the accumulation of raw concrete in the measuring container 8 from above the measuring container 8 while it is being discharged from the measuring container 8. The distance from the photographing data to the photographing point is measured and output to the controller 12 .

In S3, the control unit 12 continuously calculates the next item based on the data from the TOF camera 9, and uses it as a measured value.

·Flow speed when raw concrete is discharged

·Average shear strain

·Volume variation

(flow velocity when raw concrete is discharged)

The controller 12 calculates the discharge rate based on the amount of discharge after a predetermined time has elapsed inside the measuring container 8, that is, the amount of sedimentation due to discharge from the top surface of the pile.

That is, the amount of raw concrete discharged after t seconds (ΔV(t)) is obtained by subtracting the raw concrete volume (V(t)) from the raw concrete volume (V(t−1)) measured at t−1 seconds until t seconds. It can be calculated as a volume by the following formula.

ΔVt = V(t−1)−V(t) (cm ³ ) (1)

The flow velocity (Δvt) at the time of discharging raw concrete from t-1 sec to t sec is the area of the discharge opening (A (cm ² )) It can be calculated by the following formula divided by the measurement time interval (Δt). The relationship between the flow rate and the discharge time when raw concrete is discharged is shown in FIG. 5 (a).

Δvt=ΔVt/(A×Δt) (cm/S) (2)

(average shear strain)

The control unit 12 calculates the amount of depression (settling amount) at a specific point as an average amount of shear deformation from data taken by the TOF camera 9 of the top surface of the raw concrete deposit in the measuring container 8. As shown in FIG. 6, the upper surface of the raw concrete discharged from the measuring container 8 is concave at the center due to the shape of the measuring container 8 and its own weight when the raw concrete is discharged, and gradually enters the outer periphery. There is a characteristic of sedimentation deformation in which the height of the top surface of the sediment in the measurement container 8 is lowered by sedimentation.

This characteristic is influenced by the viscosity of raw concrete, and it appears remarkably depending on the degree of viscosity. Therefore, in the present invention, the slump and slump flow values are not estimated based on factors that indirectly affect the fluidity, but focus on the amount of shear deformation in the measuring container 8, that is, the fluidity of the raw concrete itself (that is, Directly), it was decided to estimate the slump and slump flow values.

For this shear strain, even after kneading, the viscosity of raw concrete tends to become heterogeneous depending on the deposition position, so an average value was adopted. In order to obtain the average shear strain, as shown in Fig. 6, the heights of a plurality of points on the top surface of the pile in the measuring container 8 of the flowing raw concrete are measured and averaged.

Next, the explanation continues using FIG. 6 . The TOF camera 9 includes, for example, five points including the center of a predetermined diameter region (hereinafter referred to as region I) of the central portion in the measuring container 8, and furthermore, in a concentric circle, the central portion For example, four points in the large-diameter area (hereinafter referred to as area II) from the predetermined diameter, at the timing of the predetermined interval when the raw concrete is discharged from the lower surface of the measuring container 8 The vertical height Li(t) (i is the measurement position, i = 1 to 9) of each point in the measurement is sent to the controller 12. 7 to 8 show the relationship between the shear strain and the discharge time when raw concrete is discharged.

The amount of change in the vertical direction of each point (ΔLi (t)) is the vertical height (Li (t) ) is calculated by the following formula as a value subtracted.

ΔLi(t) = Li(t-1)-Li(t) (cm) (3)

The amount of shear strain (Δγi(t)) after t seconds at each measurement point in region I is the amount of change in vertical displacement (ΔLi(t)) after t seconds at the measurement position (i) (2 to 5). It is calculated by the following formula divided by the radius (Xcm) of

Δγ2(t) = {ΔL1(t)−ΔL2(t)}/X (4-1)

Δγ3(t) = {ΔL1(t)−ΔL3(t)}/X (4-2)

Δγ4(t) = {ΔL1(t)−ΔL4(t)}/X (4-3)

Δγ5(t) = {ΔL1(t)−ΔL5(t)}/X (4-4)

The amount of shear strain (Δγi(t)) after t seconds at each measurement point in region II is the amount of change in vertical displacement (ΔLi(t)) after t seconds at the measurement position (i) (6 to 9). It is calculated by the following formula divided by the radius (X'cm) of

Δγ6(t) = {ΔL2(t)−ΔL6(t)}/X' (5-1)

Δγ7(t) = {ΔL3(t)−ΔL7(t)}/X' (5-2)

Δγ8(t) = {ΔL4(t)−ΔL8(t)}/X' (5-3)

Δγ9(t) = {ΔL5(t)−ΔL9(t)}/X' (5-4)

The average amount of shear strain (Δγ) of region I and region II is calculated by Equation 1 below, which averages the amount of shear strain calculated by four orthogonal points on the circumference.

(volume change amount)

Even if the capacity is the same, the discharge time is different depending on the viscosity, so the discharge time is shorter in the case of the smaller viscosity than the larger one. The discharge time T is the value when the accumulation amount of raw concrete in the measuring container 8 is the maximum value from the photographing of the TOF camera 9 and the distance determination, and the accumulation amount is 0, that is, the volume is 0 or the volume It is calculated as the cumulative time until the time n when the fluctuation amount becomes zero. 9 shows the relationship between the amount of change in volume of raw concrete and the discharge time.

As described above, for the flow rate of raw concrete (Fig. 5), average shear strain and discharge time (Figs. 7 to 8), and volume change (Fig. 9), Fig. 5 (b), Fig. 8 (b), As shown in Fig. 9(b), it has a simple characteristic in relation to the viscosity (slump) of raw concrete, and is provided as a model formula in the data section 13.

That is, in the method for estimating slump and slump flow values of the present invention, the flow rate in the relationship between the flow rate of raw concrete and the discharge time shown in FIG. The peak (maximum flow rate), the peak of the average shear strain (maximum average shear strain) in the relationship between the average shear strain and discharge time of raw concrete in Region I and Region II shown in Fig. 8 (b), and The data section 13 is provided with a database that records each relationship between the peak (maximum volume change) of the raw concrete fluctuation amount in the relationship between the volume change amount of raw concrete and the discharge time shown in 9(b).

As shown in Fig. 5(a), the relationship between the flow rate, slump, and slump flow value during discharge of raw concrete is that the flow rate accelerates with the discharge time, reaches the maximum (peak), and then rapidly decelerates. Although this relationship differs in the peak flow rate and the discharge time to reach the peak depending on the viscosity of the raw concrete, since it is based on the (approximately linear) relational expression shown in Fig. 5 (b) according to the viscosity of the raw concrete, the control unit (12) reads the relational expression of Fig. 5(b) from the data section 13 and compares it (S4).

As shown in Figs. 7(a), 7(b) and 8(a), the relationship between the average shear strain of raw concrete and the slump and slump flow values is related to the viscosity of raw concrete in region I and region II. Although the maximum average shear strain and the discharge time to reach the maximum shear strain are different depending on the viscosity, since it is based on the (approximate linear) relational expression shown in FIG. 8 (b) according to the viscosity of raw concrete, the control unit 12 The relational expression of 8(b) is read from the data section 13 and collated (S4).

As for the relationship between the volume change amount and discharge time, as shown in Fig. 9 (a), when the maximum volume change amount (peak) is the same volume and the viscosity is different, the discharge time to reach this peak is different, and the lower the viscosity of raw concrete, the more Since it is based on the (approximately linear) relational expression shown in Fig. 9(b), the control section 12 reads the relational expression in Fig. 9(b) from the data section 13 and compares it (S4).

The control unit 12 determines, from the data unit 13, the maximum flow velocity value, which is the peak of the flow velocity of raw concrete obtained in the above S3, the maximum average shear strain value, which is the peak of the average shear strain in the regions I and II, Based on the maximum volume change value, which is the peak value of the concrete volume change amount, the slump and slump flow estimate values for each factor are specified, and as shown in FIG. 10, the specified slump and slump flow estimate values are all included The middle of the upper and lower limits of the range is calculated, and this is used as the estimated value of the slump and slump flow obtained from the measurement results (S5).

After that, the control unit 12, as described above, to the data unit 13, the flow rate of raw concrete (Fig. 5), the average shear strain and discharge time (Figs. 7 to 8), and the amount of volume change (Fig. 9), respectively. Regarding the relationship between slump and slump flow for , the “measured value” shown in FIGS. 5 (b), 8 (b), and 9 (b) was fed back, and the estimated value of S5 and raw concrete were collected. The actual measured value of the slump test is verified (S6).

Contrary to the above, the data section 13 is, for example, the slump (fixed) value actually obtained in the slump test and the flow rate of raw concrete when the slump flow (fixed) value, average shear strain and discharge time, and volume change (b), the flow rate of raw concrete having relation data of "actual test" as shown in each of Fig. 8(b) and Fig. 9(b) and reaching the estimated value of slump and slump flow calculated in S5 , average shear strain, discharge time, and volume change, verify that the "measured value" does not deviate beyond the allowable range from the relational expression of each "actual test", and determine the validity of the estimated value of S5.

For example, since the estimated value of S5 is obtained by calculating the middle of the upper limit value and the lower limit value of the range in which both the slump and slump flow estimate values specified by each factor are included, any one or a plurality of factors are, for example, "actual test" An estimated value of S5 is calculated even if it is significantly deviating from the relational expression. In order to prevent such an error, after fixing the slump and slump flow values actually obtained by the slump test for each element, comparison and verification with each element of the pre-obtained raw concrete flow rate, average shear deformation and discharge time, and volume change amount , If an admixture is necessary/unnecessary and an admixture is needed, determine the amount and input it.

Returning to Figure 2, the control unit 12, if the time is not the last (No in #7) and separated beyond the permissible range for each element (NG in #8), the admixture for the permissible range is injected In addition, the excess or deficiency of the admixture for the separation exceeding the allowable range is fed back (#10), and the processing proceeds to #9.

On the other hand, the control unit 12, if the sashimi is not the last (No in #7) and is not separated beyond the permissible range for each element, that is, if it is an appropriate value (OK in #8), injects the admixture for the permissible range , processing proceeds to #9.

In addition, if the time is the last time (Yes in #7), the control unit 12 adjusts the amount of the admixture input (if necessary) of this time and the excess or deficiency of the admixture up to the previous time and inputs it, and the process proceeds to #9.

As described above, instead of the conventional slump test and slump flow test performed by collecting raw concrete after kneading, the flow characteristics of raw concrete itself are observed with respect to the estimated value of slump and slump flow calculated based on various related factors. Since it is supposed to be measured and calculated based on this, the estimated value obtained and the slump test and slump There is almost no deviation from the measured value of the flow test, and a highly reliable estimated value can be obtained, and based on this, the necessary / unnecessary amount of the admixture and the amount when necessary can be grasped.

(estimation of strength)

Next, the subroutine processing in #9 in Fig. 2 will be described with reference to Fig. 4. In FIG. 2, after the necessity/unnecessity of the admixture based on whether or not the slump and slump flow values are within the allowable range, the calculation of the amount when necessary, and the calculation of the excess or deficiency amount, that is, raw concrete from the measuring container 8 When is discharged to the wet batch hopper 7 (S11), the unit quantity of raw concrete is measured by the unit quantity measuring unit 7A (S12).

In S12, the unit quantity/cement quantity is calculated based on the unit quantity obtained in #3 in Fig. 2 and the dynamic load value of cement measured in #4 in Fig. 2, and this value is stored in the data unit 13. Also, the control unit 12 calculates the estimated strength based on the unit quantity (S14).

Then, various measured values before kneading obtained in #4 of FIG. 2 and the estimated intensity value after kneading in S14 are read from the data unit 13, and the control unit 12 makes an acceptable determination of the estimated strength (S15). In the judgment in this judgment part 12C, judgment is made about the following conditions.

In S15, whether or not the upper limit of the unit quantity is 195kg/m ³ or less, whether the ratio of the unit quantity/cement quantity is less than 60% or less than 65% depending on the type of cement, among the ranges of the minimum and maximum values of the estimated strength Whether or not the lowest value satisfies the required intensity and whether or not the occurrence probability of the lowest value is 95% or more is determined, respectively. In addition, the reason for setting the numerical value in each of these shipping disqualification conditions will be described later.

In the judgment at S15, if even one is not satisfied (unsuitable at S15), the control unit 12 calculates the excess or deficiency of the moisture amount according to the unsatisfied judgment condition (S16), and if all are satisfied (S15 fit in), the process proceeds to #11 in FIG.

The above conditions are explained here. In general, the concrete used in reinforced concrete structures has a coating thickness of 3cm for the reinforcing bars, and with this coating thickness, the allowable amount of 185kg/m ³ ± 10kg/m ³ It is recommended to use the unit quantity of Therefore, if the unit water content is higher than 195 kg/m ³ , the plus side of the tolerance ±10 kg/m ³ of 185 kg/m ³ guaranteed by the regulations is exceeded, and in this case, the moisture content is that much.

In addition, since there are cases where the durability of cement cannot be measured only by the above unit quantity (quantity), the ratio of unit quantity/cement quantity is used as a judgment of whether or not to ship. Depending on the type of cement, even if the ratio of unit water/cement quantity is higher than 60% or 65%, since it means that the ratio of water to cement is high, there is a possibility that the above 60 years or more rust prevention guarantee may not be satisfied, determines that adjustment is necessary.

In addition, with regard to whether or not the lowest value in the range of the minimum and maximum values of the estimated strength meets the required strength, the lowest value in the strength range calculated centering on the unit quantity after kneading (S14: calculated value after kneading) is the desired desired strength. Even when the strength (#1 in Fig. 2) is lower than the required strength, it is determined that the amount of moisture needs to be adjusted.

In addition, even if the lowest value in the strength range (S14: calculated value after kneading) calculated based on the unit quantity after kneading is higher than the required strength, if the probability of occurrence of the lowest value is lower than 95%, the lowest value higher than the required strength Since the possibility of expression cannot be guaranteed, it is determined that adjustment of the moisture content is necessary.

As described above, considering that there is an error between the required strength based on the order (#1 in Fig. 2) and the calculated value immediately before shipment (S14: calculated value after kneading), all strict conditions are met. Since it is judged that water content adjustment is unnecessary only after shipment, it is possible to remarkably suppress the occurrence of problems in terms of strength and durability after shipment.

Returning to FIG. 2, the control unit 12, when the time is not the last (No in #11) and water content adjustment based on the inconsistency of the estimated strength is required (NG in #12), provides feedback of the excess or deficiency of the water. (#14), and processing proceeds to #13.

On the other hand, the control unit 12 proceeds to #13 if the time is not the last (No in #11) and no inconsistency occurs in the estimated strength, that is, if it is an appropriate value (OK in #12).

Further, in the case of the last session (Yes in #11), the controller 12 adjusts the amount of water if there is an amount of water adjustment up to the previous time, and the process proceeds to #13.

In #13, raw concrete of all manufacturing batches divided into multiple batches is discharged to the same mixer truck. That is, in the present invention, so-called trial mixing does not exist, which is discarded because it is not suitable for shipment (even if it is suitable). This is, for example, even if there was a shortage in the amount of admixture and moisture in the first time, in the second time (the last time in this embodiment), the amount of the admixture and the amount of moisture that were insufficient in the first time was added (increased for the last time), and the second time This is because it is manufactured and mixed until it arrives at the pouring site in the same mixer truck.

By doing the same as in the present invention, since the entire amount is manufactured while repeating minute adjustments as the number of manufactures is divided by simple calculation, the overall error is small, and as a result, raw concrete with a quality very close to the order can be shipped. there is.

1: (raw concrete manufacturing) facilities
2: Cement draw-out
2A: Cement dynamic load measurement unit
3: Aggregate withdrawal part
3A: Aggregate dynamic load measurement unit
3B: surface yield measurement unit
4: water supply
4A: water dynamic load measurement unit
5: admixture withdrawal part
5A: admixture dynamic load measurement unit
6: kneading device
7: wet batch hopper
7A: unit quantity measuring unit
11: management department
12: control unit
12A: calculation unit
12B: mixing instruction unit
12C: Judgment
13: data part
14: input unit
15: output unit

Claims (4)

Divide the production of ready mixed concrete into at least two times, calculate the division amount by dividing all the concrete materials by the number of times of production, and divide the entire amount of the concrete material ordered so that the division amount for each time is divided into a plurality of the above at least two times Each equally divided dynamic load is measured, and then kneaded, and estimated values of slump and slump flow are calculated for the raw concrete after kneading, and the required slump and By comparing the slump flow value, the necessary/unnecessary and necessary amount of admixture is adjusted, and the estimated strength of the raw concrete is subsequently obtained, and it is judged whether this estimated strength is an appropriate value or not, and the next meeting of unsuitable A raw concrete manufacturing method in which the raw concrete produced by multiple times is mixed in the same mixer truck by adjusting the increase or decrease of the water content in consideration of the previous time in the first time.
The production of raw concrete is divided into at least two times, the division amount obtained by dividing all the concrete materials by the number of times of production is calculated, and each dynamic load obtained by equally dividing the entire amount of the concrete material ordered so that the division amount for each time is equally divided into the plurality of at least two times are measured, these are kneaded, and estimated values of slump and slump flow are calculated for the raw concrete after kneading, and compared with the required slump and slump flow values, in the next time of the inappropriate time, the increase or decrease of the amount of the admixture is adjusted considering the previous time. and, subsequently, the estimated strength of the raw concrete after kneading is obtained, compared with the required strength, and the increase or decrease of moisture is adjusted to mix the raw concrete produced multiple times in the same mixer truck.
The production of raw concrete is divided into at least two times, the division amount obtained by dividing all the concrete materials by the number of times of production is calculated, and each dynamic load obtained by equally dividing the entire amount of the concrete material ordered so that the division amount for each time is equally divided into the plurality of at least two times Measured, kneaded them, and confirmed whether it was the last time among the number of manufactures,
Unless it's the finale
When the judgment on the slump and slump flow value is appropriate and the judgment on the estimated strength is appropriate, an instruction is given to the mixer truck as it is,
When the judgment on the slump and slump flow value is appropriate and the judgment on the estimated strength is unsuitable, the excess and deficiency amount of moisture is calculated and fed back, and an instruction is given to the mixer truck,
If the judgment on the slump and slump flow value is inappropriate, the excess or deficiency of the admixture is calculated and fed back, and if the judgment on the estimated strength is appropriate, the mixer truck is instructed to take out as it is,
If the judgment on the slump and slump flow value is inappropriate, the excess or deficiency of the admixture is calculated and fed back.
In the final round,
Adjust the increase or decrease considering the amount of excess or deficiency of admixture fed back to the previous time, and also adjust the increase or decrease considering the amount of excess or deficiency of moisture fed back to the previous time, and take it out with the same mixer truck as above,
A raw concrete manufacturing method in which raw concrete produced by multiple times is mixed in the same mixer truck.
Cement, aggregate, surface yield of aggregate, measurement unit that measures water and admixture corrected based on the surface yield of aggregate, and various calculations and judgments based on these measurement units, as well as overall An input unit for instructing and inputting the mixing amount of raw concrete ordered to the management unit, an instruction unit for instructing input of cement and aggregate in the mixing ratio input to the input unit, and upper and lower surfaces A measuring container arranged in the shape of a hollow truncated cone with a large diameter on the upper surface and a small diameter on the bottom surface, and a TOF arranged obliquely above the opening on the upper surface in this measuring container. (Time of Flight) Equipped with a camera,
Even if the production of raw concrete is small, the production of raw concrete is divided into at least two times, the division amount obtained by dividing all the concrete materials by the number of times of production is calculated, and the total amount of the concrete material ordered to be the division amount for each time is divided into the above at least two times. In addition to measuring each dynamic load divided into plural equal parts and determining whether or not the current manufacturing round is the final round,
(1) Finding the estimated strength of raw concrete after kneading, determining whether this estimated strength is an appropriate value, and adjusting the amount of moisture in consideration of the previous time at the next time after the unsuitable time,
(2) Calculate the estimated value of the slump and slump flow of the raw concrete after kneading, compare it with the required slump and slump flow value, and adjust the amount of the admixture in consideration of the previous time in the next time of the unsuitable time,
A raw concrete manufacturing facility further comprising a control unit that performs at least (1) among them.

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