JP2003177115A - Quality control system for high-fluidity concrete - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the qualities of high-fluidity concrete using values obtained by observed conditions of freshly mixed high-fluidity concrete during kneading and discharging. <P>SOLUTION: This system is provided with a measuring unit 2 which measures vibration and noise produced by a mixer while high-fluidity concrete is kneaded, a spectrum analyzing means 3 which analyzes spectrums of the measured vibration and noise, and a quality estimating unit 4 which estimates qualities of the high-fluidity concrete using results of the spectral analysis. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to quality control of high fluidity concrete.

[0002]

2. Description of the Related Art Conventionally, there is a slump as an index showing the softness of ready-mixed concrete, and quality control is performed so as to approach a target value. In the case of conventional ready-mixed concrete, there is a high correlation between the mixer load (electric power, current, hydraulic pressure) value when kneading and the slump, and the slump was estimated from the mixer load when kneading. In addition, although the materials used are best managed to meet the conditions at the time of design, in reality, due to qualitative variations in the materials used and errors in the estimation of surface water on the fine aggregate, the slump will exceed the target value. Sometimes they are far apart. In such a case, the surface water of the fine aggregate seems to be the biggest factor of the error.Therefore, the surface water of the fine aggregate is carefully adjusted while considering the surface water meter indication value and the slump value of the finished ready-mixed concrete. is doing. At this time, the slump is visually checked on the monitor screen.

In recent years, the demand for high-fluidity concrete has increased. This high-fluidity concrete is a concrete that is suitable for use in a place where it is difficult to fill it with ordinary concrete, such as a section with a thin section or a structure with a large amount of rebar. It is a concrete with fluidity that does not require hardening work. In other words, high-fluidity concrete has higher fluidity than ordinary concrete, and because it has an appropriate viscosity, it is possible to easily obtain homogeneous concrete with less material separation and workability in pumping etc. It is an excellent concrete.

As a method for evaluating the fresh property of high-fluidity concrete, that is, the quality of fresh concrete, slump flow is used for fluidity and 50 is used for viscosity.
A method of measuring cm slump flow time, funnel flow time for separation resistance, and the like is known.

[0005]

Therefore, according to the prior art, it was attempted to estimate the slump flow from the mixer load (electric power, current, hydraulic pressure) value when mixing ready-mixed concrete in high-fluidity concrete. In this case, it is difficult to estimate the slump flow because this correlation is small (close to no correlation). ITVs being kneaded and discharged by a skilled person
Even if you look at the image, you cannot find the slump flow at all. Therefore, it is an object of the present invention to enable quality control of high-fluidity concrete based on the values observed during mixing and discharging other than the mixer load (electric power, current, hydraulic pressure) values.

[0006]

In order to solve the above-mentioned problems, in a high-fluidity concrete quality control system according to claim 1 of the present invention, vibrations and sounds generated from a mixer during kneading of high-fluidity concrete are measured. The measurement means, the spectrum analysis means for spectrum-analyzing the measured vibration and sound, and the quality estimation means for estimating the quality of the high-fluidity concrete from the result of the spectrum analysis.

In the quality control system for high-fluidity concrete having the above-mentioned structure, it is possible to estimate an abnormality during the kneading of the high-fluidity concrete by spectral analysis of vibration and sound generated from the mixer during the kneading of the high-fluidity concrete, and It is possible to estimate whether or not the high-fluidity concrete has been mixed to the desired quality.

According to a second aspect of the present invention, in the high-fluidity concrete quality control system according to the first aspect, the vibration or sound generated from the mixer is vibration of the mixer load, vibration of the mixer, or mixing sound. And

In the above structure, the quality of the high-fluidity concrete can be controlled by spectrally analyzing the vibration of the mixer load, the vibration of the mixer, or the mixing sound when kneading the high-fluidity concrete.

Further, in the quality control system for high-fluidity concrete according to claim 3, measuring means for measuring vibration and sound generated when the kneaded high-fluidity concrete is discharged from the mixer, and spectrum analysis of the measured vibration and sound. A spectrum analysis unit and a quality estimation unit that estimates the quality of the high-fluidity concrete from the result of the spectrum analysis are provided.

In the high-fluidity concrete quality control system having the above-mentioned structure, it is possible to estimate the abnormality of the high-fluidity concrete by spectral analysis of vibrations and sounds generated when the kneaded high-fluidity concrete is discharged from the mixer, and It is possible to estimate whether the liquid concrete has been mixed to the desired quality.

According to a fourth aspect of the present invention, in the high-fluidity concrete quality control system according to the third aspect, vibrations and sounds generated when the high-fluidity concrete is discharged from the mixer are vibrations of a mixer load, vibrations of a concrete hopper, or , The sound of falling into the concrete hopper.

In the above structure, the quality of the high-fluidity concrete is controlled by spectrally analyzing the vibration of the mixer load when the high-fluidity concrete is discharged from the mixer, the vibration of the concrete hopper, or the sound of dropping into the concrete hopper. You can

According to a fifth aspect, in the high-fluidity concrete quality control system according to any one of the first to fourth aspects, the quality estimating means estimates a slump flow which is an index of fluidity from the result of the spectrum analysis. It is characterized by estimating the quality of high flow concrete.

In the above structure, the quality control of high-fluidity concrete is performed by estimating the slump flow from the correlation between the result of spectrum analysis and the slump flow which is an index of fluidity.

According to a sixth aspect of the present invention, in the high-fluidity concrete quality control system according to any of the first to fifth aspects, the quality estimating means uses the result of the spectrum analysis as a slump index for viscosity and material separation resistance. The quality of high-fluidity concrete is estimated by estimating the flow time, the 50 cm slump flow time, the funnel downflow time, and the like.

In the above structure, the slump flow time, 50 cm slump flow time, and funnel flow time are correlated from the results of spectrum analysis and the correlation between slump flow time, 50 cm slump flow time, and funnel flow time, which are indicators of viscosity and material separation resistance. Estimate the time to control the quality of high-fluidity concrete.

According to a seventh aspect, in the high-fluidity concrete quality control system according to any of the first to sixth aspects, in addition to the result of the spectrum analysis, temperature, surface water of fine aggregate, cement type, admixture use It is characterized by estimating the quality of high-fluidity concrete, including information about the amount and other mixing.

In the above structure, the quality of the high-fluidity concrete is considered in consideration of the mix of the concrete including not only the result of the spectrum analysis but also the temperature, the surface water of the fine aggregate, the kind of the cement, and the kneading such as the admixture. Can be estimated. The type of cement is ordinary Portland cement.
There are blast furnace cement, low heat Portland cement, etc.,
Other than that, it also includes differences depending on the manufacturer.

According to an eighth aspect, in the high-fluidity concrete quality control system according to any one of the first to seventh aspects, the quality estimating means performs spectrum analysis in advance to obtain an average value of vibration intensity at each frequency. It is characterized by monitoring whether or not the result of spectrum analysis of the measured vibration or sound is within the range of the allowable value based on the average value, and monitoring the abnormality relating to the kneading of the high-fluidity concrete.

In the above-mentioned structure, the average of the vibration intensity at each frequency is obtained in advance from the result of the spectrum analysis, and the abnormality related to the kneading of the high-fluidity concrete is monitored depending on whether the result is within a certain range from the average. be able to.

According to a ninth aspect, in the high-fluidity concrete quality control system according to the eighth aspect, the permissible value is a standard deviation value, and spectrum analysis is performed in advance and the average value and the standard deviation of the vibration intensity at each frequency are set. It is characterized in that it is judged whether or not it is within the range obtained from the value and the abnormality related to the kneading of the high-fluidity concrete is monitored.

In the above construction, the average and standard deviation of the vibration intensity at each frequency are obtained in advance from the result of spectrum analysis, and the high-fluidity concrete is determined whether or not the spectrum is within the range determined by the standard deviation from the average. It is possible to monitor abnormalities related to kneading.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described below with reference to the drawings. The high-fluidity concrete quality control system 1 according to the present embodiment, as shown in FIG.
A measuring unit 2 for measuring the vibration of a mixer during mixing of fresh concrete and a vibration during discharging of fresh concrete, an analyzing unit 3 for spectrally analyzing the measured vibration, and a quality estimating unit 4 for estimating quality from the analyzed spectrum. Constitute. In addition, a concrete kneading apparatus generally includes a storage bin 5 for storing aggregates and cement, a weighing bottle 6 for weighing materials taken out from the storage bin 5, a mixer 7 for kneading fresh concrete, and a kneading machine. It is composed of a concrete hopper 8 for discharging the ready-mixed concrete.

Further, the high-fluidity concrete is a concrete whose flowability is remarkably enhanced without impairing the material separation resistance during freshness, and includes superfluid concrete, compaction-free concrete, self-compacting concrete, high-performance concrete, high-performance concrete. It is a concept that includes concrete and the like.

The measuring unit 2 measures the vibration of the mixer 7 and the mixing sound when the high-fluidity concrete is mixed. The sound of the mixer 7 can be measured by the sound collecting device 21 such as a microphone. Alternatively, it is also possible to install a video camera and measure the recorded sound by using audio software (such as a sound recorder) such as a personal computer.

The analysis unit 3 spectrally analyzes the measured vibrations and sounds. Here, as shown in FIG.
Vibration and noise during kneading measured during one batch with
It has a function of obtaining a power spectrum (FIG. 2B) from (a)) and observing a frequency f included in vibration or sound and a power P which is the vibration intensity of the frequency component. As a spectrum analysis method, in addition to power spectrum analysis,
Fast Fourier Transform (FFT)
And maximum entropy method (MEM: MaximumEntropy Metho
It is also possible to analyze with d) or wavelet analysis. Hereinafter, the case where the analysis unit 3 analyzes using a power spectrum will be described.

The quality estimating unit 4 has a function of estimating whether or not the quality of the ready-mixed concrete is desired based on the spectrum analysis. There is a correlation between the power at a certain frequency of the power spectrum obtained by the spectrum analysis and the fluidity index such as slump flow. Therefore, a value such as slump flow, which is an index of liquidity, is estimated from the correlation. Alternatively, in addition to the power spectrum analyzed by spectrum analysis, values such as slump flow may be estimated by including information on kneading such as temperature, surface water of fine aggregate (sand etc.), cement type, admixture usage, etc. good.

In addition to slump flow, quality indicators include slump flow time, which is an index of viscosity and material separation resistance, 50 cm slump flow time, funnel flow-down time such as O-funnel test and V-funnel test. These may be estimated. Alternatively, as shown in FIG. 3, it is estimated whether or not the ready-mixed concrete meets the desired quality depending on whether or not the result of the spectrum analysis is within a certain range.

Therefore, the operation using the high-fluidity concrete quality control system 1 which is an example of this embodiment having the above-mentioned configuration will be described. Further, in the present embodiment, a case will be described in which the mixing sound of the mixer during kneading is measured and the fluidity is estimated using the slump flow. First, in order to control the quality of high-fluidity concrete at the time of kneading the high-fluidity concrete, for example, N batch (preferably as much as possible) experiments were conducted, and vibrations and sounds were measured and spectrum analysis was performed. The correlation between the results and the quality of high-fluidity concrete is sought.

First, the measuring section 2 measures the sound during kneading,
When the analyzing unit 3 performs the spectrum analysis for N batches, N power spectra are obtained. When this power spectrum is overlaid and displayed, it is displayed as shown in FIG. Figure 3
The vertical axis of (a) represents the power P of vibration and the horizontal axis represents the frequency f. Therefore, the average of the power at each frequency is calculated,
Furthermore, the standard deviation is calculated. The reference power spectrum is obtained from the average of the powers at each frequency, and for example, plus or minus 2
A region having a width of double standard deviation σ is set as a range that can usually be taken.

Average power mean at the frequency fα (P (f
α)) and its standard deviation σ (fα) are obtained as follows.

[Formula 1] Therefore, at frequency fα, mean (P (fα))-2σ (fα) to mean (P (fα))
It is determined that the power within the range of + 2σ (fα) is normal. In the entire frequency range, it is the filled-in portion D as shown in FIG. Hereinafter, the line representing this area is referred to as a range curve D.
Assuming that the power spectrum values are normally distributed on each frequency axis, the measured power spectrum of the sound (vibration) is
It is believed that there is a 95% probability of being within this range curve. The range curve is not limited to ± 2 times the standard deviation and may be set appropriately.

Further, the vibration measured by the measuring unit 2 is calculated by the analyzing unit 3 for the power spectrum for N batches, and the result is shown in FIG.
As shown in (FIG. 3 (a)), the relationship with the slump flow SF is analyzed from the superimposed display. That is, FIG. 4B shows a graph in which the correlation between the power P and the slump flow SF at a certain frequency f is calculated, and the correlation is calculated for all frequency bands. In FIG. 4B, the vertical axis represents the correlation coefficient R and the horizontal axis represents the frequency f. Correlation coefficient R is -1.0
It is represented by ~ 1.0, and the closer it is to ± 1.0, the higher the degree of correlation.

FIG. 4C is a scatter diagram showing the relationship between the power P of the frequency fα and the slump flow SF. G is
It is a linear regression of the sample in the figure, and R is a correlation coefficient (at the frequency fα) between two variables of the power P and the slump flow SF.

Therefore, the slump throw SF can be obtained from the frequency at which the correlation is recognized. For example, when the frequency having a strong correlation with the slump flow is fα, the slump flow estimation model can be expressed as the slump flow estimated value = F (P (fα)). However, F represents a function.

Therefore, an example of a slump flow estimation model and its estimation method will be shown. 1) Model in which the power value of a specific frequency has a high correlation Here, the case where the power of the power spectrum and the slump flow are considered to have a relationship represented by a linear expression will be considered. If there is a high correlation at some frequency fα, the slump flow estimate SF is

[Formula 2] Ask in. In this example, the spectrum analysis of the actually measured vibration data is performed, P (fα) is calculated, and the calculated value is substituted into Equation 2 to calculate the estimated value of the slump flow. Equation 2 is the simplest model for directly estimating the slump flow. Although the case where the slump flow has a linear relationship with P (fα) has been described here, a function F including various terms such as a square term and a term represented by an exponent is given, and SF = F (P (fα )).

2) Besides the model using the power values of a plurality of frequencies, the estimated value of the slump flow is a specific frequency fα.
Not just modeled in relation to. For example, power values P (f ₁ ), P (f ₂ ), ...
This is a function that has (f _q ) as an explanatory variable.
A model for estimating is also possible. It may be obtained as SF = F (P (f ₁ ), P (f ₂ ), ..., P (f _q )). For example,

[Formula 3] Ask from.

3) Model using power values at a plurality of frequencies and other information about kneading Power values at a plurality of frequencies P (f ₁ ), P (f ₂ ), ...
., P (f _q ), in addition to kneading information (temperature, surface water of fine aggregate, cement type, admixture usage, etc.) X ₁ , X ₂ , ..., X _r are explanatory variables The model to be considered is also considered. At this time, the slump flow estimated value SF is SF = F (P (f ₁ ), P (f ₂ ), ..., P (f _q ), X ₁ ,
X ₂ , ..., X _r ) may be used. However, X ₁ , X ₂ , ...
-, the X _r Specifically, temperature, surface water fine aggregate, cement type considered and admixtures usage. For example,

[Formula 4] Ask from.

4) It is also possible to use a neural network (back propagation method) H as the nonlinear model or the nonlinear model. Information about the power values P (f ₁ ), P (f ₂ ), ..., P (f _q ) of various frequencies and the kneading in the neural network H (temperature, surface water of fine aggregate, cement type,
Amount of admixture, etc.) X ₁ , X ₂ , ..., X _r are associated with each unit, and SF = H (P (f ₁ ), P (f ₂ ), ..., P (f _q ), X ₁ ,
X ₂ , ..., X _r ). In the case of a neural network, each unit often operates in a non-linear relationship such as a sigmoid function.

The slump flow estimation model for obtaining the slump flow SF by various methods has been described above.
At this time, the frequencies for which the correlation is recognized are displayed by superimposing a power spectrum 11 on the screen 10 as shown in FIG. 5, and further, a slump flow of a specific frequency and a power scatter diagram 12 and the entire frequency range are displayed. The correlation coefficient 13 of is displayed, and the place where the correlation is considered to be high is directly or automatically designated and taken out. Further, the mixer load curve 14 which has been conventionally performed can also be displayed together.

Therefore, the quality estimating unit 4 estimates the fresh property of high-fluidity concrete such as slump flow from the above range curve (FIG. 3B) and the slump flow estimation model. First, in the quality estimation unit 4, as shown in FIG. 3, the range curve D is displayed on the screen, and the power spectra of one batch are displayed in an overlapping manner. At this time, the range curve
If a part outside D appears, it is assumed that there is some abnormality. Further, the estimated value of the slump flow is calculated from the above estimation model.

Further, it is preferable that the set range curve is constructed by recent manufacturing data so as to conform to recent quality, not absolute one. Therefore, it is preferable to update the data as it is accumulated every time one batch is measured.

Further, as a result of the actual measurement, the appearance of the correlation varies depending on the composition. It depends on the target slump flow, type of cement, and type of admixture (high-performance AE water reducing agent, etc.), so it is necessary to construct different models for each.

As described above, in the first embodiment, the sound at the time of kneading can be measured and the quality of the high-fluidity concrete can be managed so as to have a desired quality.

Next, as a second embodiment, a case of analyzing the sound when the kneaded high-fluidity concrete is discharged from the mixer 7 will be described.

The configuration is the same as that of the first embodiment, except that the sound at the time of discharging is measured and the quality is controlled. Only the different points will be described. The measuring unit 2 measures the sound of falling onto the concrete hopper 8. The sound of the concrete hopper 8 can be measured by the sound collector 21 such as a microphone. Alternatively, the sound recorded by installing a video camera can be measured by using audio software (such as a sound recorder) such as a personal computer.

The analyzing section 3 analyzes the spectrum of the measured sound. Here, the power spectrum is obtained from the sound at the time of discharge measured by the measuring unit 2 during one batch, and the frequency f and its power P included in the vibration or sound are observed. The other configuration and the operation by this configuration are the same as those described in the first embodiment, and thus detailed description will be omitted.

As described above, in the second embodiment, the sound at the time of discharge can be measured and the quality of the high-fluidity concrete can be managed so as to have a desired quality.

Next, as a third embodiment, as shown in FIG. 6, a drive load (power, current, power) of a motor for rotating a mixer arm when kneading high-fluidity concrete.
The case of analyzing the vibration of hydraulic pressure) will be described.

The configuration is the same as that of the first embodiment, except that the vibration of the drive load of the motor for rotating the mixer arm is measured and the quality is controlled. Only the different points will be described. The measuring unit 2 can also measure the vibration of the drive load (electric power, current, hydraulic pressure) of the motor 22 for rotating the mixer arm. When measuring the vibration of the drive load of the motor, the vibration of the drive load of the motor is measured with a power converter, an ammeter, an oil pressure gauge, or the like.

In the analysis unit 3, the measured vibration of the drive load of the motor is spectrally analyzed. Here, the measuring unit 1
A power spectrum is obtained from the vibration of the driving load of the motor measured during the batch, and the frequency f and its power P included in the vibration are observed. The other configuration and the operation by this configuration are the same as those described in the first embodiment, and thus detailed description will be omitted.

As described above, in the third embodiment, the vibration of the driving load of the motor can be measured and the quality of the high-fluidity concrete can be controlled to a desired quality.

Next, as a fourth embodiment, as shown in FIG. 7, a case of analyzing the vibration of the mixer 7 at the time of kneading the high-fluidity concrete and the vibration of the concrete hopper 8 at the time of discharging from the mixer will be described. To do.

The configuration is the same as that of the first embodiment, except that the vibration of the mixer 7 during kneading and discharging is measured to control the quality. Only the different points will be described. When measuring the vibration of the mixer 7, the measuring unit 2 installs an accelerometer 23, a laser displacement measuring instrument 23, or the like on the mixer 7 and measures the vibration (solid line in FIG. 7). When measuring the vibration of the concrete hopper 8 when it is discharged from the mixer, the concrete hopper 8 is provided with an accelerometer 23, a laser displacement measuring device 23, or the like (the broken line in FIG. 7).

The analysis unit 3 performs spectrum analysis on the measured vibration. Here, the power spectrum is obtained from the vibration at the time of kneading or the vibration at the time of discharging measured by the measuring unit 2 during one batch, and the frequency f and its power P included in the vibration are observed. The other configuration and the operation by this configuration are the same as those described in the first embodiment, and thus detailed description will be omitted.

As described above, in the fourth embodiment, the vibration of the mixer 7 at the time of kneading or the vibration of the concrete hopper 8 at the time of discharging from the mixer is measured to bring the quality of the high-fluidity concrete to the desired quality. Can be managed to be.

Although the slump flow has been described in the above embodiment, the funnel flow-down time, the slump flow time, the 50 cm slump flow time, etc., such as the O funnel test and the V funnel test can be estimated in the same manner.

Further, there is a relation between the decay state of the mixer load value at the time of discharging the mixer and the elapsed time, and from this, the raw concrete falling state can be grasped. Therefore, it is expected that the funnel downflow time can be estimated by investigating the relationship between the decay state of the mixer load value and the elapsed time. It is also possible to control the quality of high-fluidity concrete by estimating this funnel flow time.

Further, various results can be obtained by looking at the results of analysis in the embodiments described in detail above, for example, by making a determination by combining the analysis of the kneading noise and the analysis of the vibration of the driving load of the motor. It is possible to combine them into more precise ones.

[0060]

EXAMPLE An example will be described below for confirming the correlation between the load of the mixer and the slump flow, but the present invention is not limited to the mode shown in the example.

FIG. 8 shows the correlation between the mixer load and the slump flow examined in the same manner as the conventional method. FIG. 8A shows the batch number, the mixer load, and the actual measurement value of the slump flow at that time. FIG. 8B is a scatter diagram of the mixer load and the slump flow at that time, but no correlation is seen.

(1) Mixing Sound of Mixer and Dropping Sound to Concrete Hopper Then, as shown in FIG. 9, a video camera is installed in the concrete hopper to collect the mixing sound of the mixer and the dropping sound to the concrete hopper. It is an experimental result which analyzed the power spectrum.

The compounding was carried out for those shown in the following table.

[Table 1] In Table 1, W / C is the water cement ratio, s / a is the fine aggregate ratio, SF is the slump flow, and C type is the cement type.

FIG. 10 shows the result of analyzing the correlation between the power spectrum of the kneading sound (FIG. 10 (a)) and the slump flow in the blending on the first day and the third day (FIG. 10 (b)), There is a frequency band in which the relation number is 0.7 to 0.9.
FIG. 11 shows the result of analyzing the correlation between the power spectrum of the emission sound (FIG. 11 (a)) and the slump flow in the combination on the first day and the third day (FIG. 11 (b)), and the correlation coefficient is 0.9
There is a frequency band indicating the degree.

FIG. 12 shows the result of analyzing the correlation between the power spectrum of the kneading sound (FIG. 12 (a)) and the slump flow in the blending on the second day and the fourth day (FIG. 12 (b)). There is a frequency band having a relation number of about -0.8. FIG. 13 shows the result of analyzing the correlation between the power spectrum of the emission sound (FIG. 13 (a)) and the slump flow in the formulation on the second day and the fourth day (FIG. 13 (b)), and the correlation coefficient is -0.7
There is a frequency band indicating the degree or about 0.7 to 0.8.

When all of the first to fourth days were examined, no significant correlation was found when the power spectrum of the kneading sound / discharge sound and the slump flow were analyzed.

As shown above, there is a high correlation between the power spectrum of the kneading sound and the discharge sound and the slump flow at a specific frequency. Further, this correlation has different characteristics depending on the content of the mixture of high-fluidity concrete.

(2) Vibration of Mixer Load Electric Power Next, as shown in FIG. 6, a result of measuring the vibration of the mixer load electric power at the time of discharging will be examined. FIG. 14 shows the result of analysis of the correlation between the power spectrum (FIG. 14A) of the vibration of the mixer electric power after discharge (trend removal and standardization) and the slump flow (FIG. 14B), There is a frequency band having a relation number of about 0.7.

As shown in FIG. 14, there is a high correlation between the power spectrum of the vibration of the mixer load power at the time of discharge and the slump flow at a specific frequency.

(3) About Vibration of Mixer Next, as shown in FIG. 7, the result of measuring the vibration of the mixer at the time of kneading with an accelerometer will be examined. Figure 15
Represents the result of analyzing the correlation between the power spectrum of vibration of the mixer during kneading (FIG. 15 (a)) and the slump flow (FIG. 15 (b)), and the correlation coefficient is 0.7 to 0.
There is a frequency band indicating 9.

As shown in FIG. 15, the power spectrum of the vibration of the mixer at the time of kneading and the slump flow show a high correlation at a specific frequency.

[0072]

As described in detail above, according to the present invention, slump flow and the like can be predicted when kneading high-fluidity concrete, and therefore it can be judged whether kneading has been properly performed or not.

By accumulating the actual measurement results, the operation guideline for approaching the target slump flow can be examined. Also,
The record of the estimated slump flow can be used as a clue for handling complaints, etc., and stable quality products can be shipped. Furthermore, if there is an abnormality, it is possible to notice it when kneading. In addition, even an unskilled person can manufacture it.

The accuracy can be improved by adding and analyzing information on temperature, surface water of fine aggregate, kind of cement, kneading agent and the like.

Furthermore, it is possible to immediately judge a clear abnormality related to kneading by checking whether the result is within the allowable range.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a high-fluidity concrete quality control system (No. 1).

FIG. 2 is a diagram for explaining spectrum analysis of measured vibrations and sounds.

FIG. 3 is a diagram for explaining a range curve for spectrum analysis.

FIG. 4 is a diagram showing a relationship between a power spectrum and a slump flow.

FIG. 5 is an example in which the relationship between the power spectrum and the slump flow is displayed on the screen.

FIG. 6 is a schematic diagram of a high fluidity concrete quality control system (No. 2).

FIG. 7 is a schematic diagram of a high-fluidity concrete quality control system (No. 3).

FIG. 8 is a diagram showing the correlation between the load of the mixer and the slump flow.

FIG. 9 is an example of an apparatus for collecting a mixer kneading sound and a sound falling to a concrete hopper.

FIG. 10 is a result of analyzing a relationship between a power spectrum and a slump flow (No. 1).

FIG. 11 is a result of analyzing the relationship between the power spectrum and the slump flow (No. 2).

FIG. 12 is a result of analyzing a relationship between a power spectrum and a slump flow (No. 3).

FIG. 13 is a result of analyzing the relationship between the power spectrum and the slump flow (No. 4).

FIG. 14 is a result of analyzing a relationship between a power spectrum and a slump flow (No. 5).

FIG. 15 is a result of analyzing the relationship between the power spectrum and the slump flow (No. 6).

[Explanation of symbols]

1 High-fluidity concrete quality control system 2 measuring section 3 Analysis Department 4 Quality estimation section 5 storage bottles 6 weighing bottles 7 mixer 8 concrete hoppers 10 screens 11 Power spectrum 12 Scatter plot 13 Plot of correlation coefficient 14 Mixer load curve 21 sound collector 22 motor 23 Accelerometer (laser displacement meter)

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Claims (9)

[Claims] 1. A measuring means for measuring vibrations and sounds generated from a mixer during kneading of high-fluidity concrete, a spectrum analyzing means for spectrally analyzing the measured vibrations and sounds, and a high-fluidity concrete from the result of the spectrum analysis. A quality control system for high-fluidity concrete, comprising: 2. The high-fluidity concrete quality control system according to claim 1, wherein the vibration or sound generated from the mixer is vibration of a mixer load,
High-fluidity concrete quality control system characterized by mixer vibration or mixing sound. 3. A measuring unit for measuring vibrations and sounds generated when the kneaded high-fluidity concrete is discharged from the mixer, a spectrum analyzing unit for spectrum-analyzing the measured vibrations and sounds, and a high-value unit based on the result of the spectrum analysis. A high-fluidity concrete quality control system comprising: a quality estimating means for estimating the quality of fluidized concrete. 4. The high-fluidity concrete quality control system according to claim 3, wherein vibrations and sounds generated when the high-fluidity concrete is discharged from the mixer are vibrations of the mixer load, vibrations of the concrete hopper, or vibrations to the concrete hopper. High-fluidity concrete quality control system characterized by falling sound. 5. The high-fluidity concrete quality control system according to claim 1, wherein the quality estimating means estimates a slump flow, which is an index of fluidity, from the result of the spectral analysis to obtain a high-fluidity concrete. A high-fluidity concrete quality control system characterized by estimating quality. 6. The high-fluidity concrete quality control system according to claim 1, wherein the quality estimating means uses a slump flow time as an index of viscosity and material separation resistance from the result of the spectrum analysis, and a 50 cm slump. A high-fluidity concrete quality control system that estimates the quality of high-fluidity concrete by estimating the flow time and the funnel flow-down time. 7. The high-fluidity concrete quality control system according to any one of claims 1 to 6, wherein in addition to the result of the spectrum analysis, the temperature, surface water of the fine aggregate, the type of cement, the amount of the admixture used, and the like are mixed. A high-fluidity concrete quality control system that estimates the quality of high-fluidity concrete including information. 8. The high-fluidity concrete quality control system according to claim 1, wherein the quality estimating means performs spectrum analysis in advance to obtain an average value of vibration intensity at each frequency, and measures the measured vibration or vibration. High-fluidity concrete quality control system characterized by observing whether or not the result of spectrum analysis of sound is within a range of allowable values based on the average value, and monitoring abnormality relating to kneading of high-fluidity concrete . 9. The high-fluidity concrete quality control system according to claim 8, wherein the allowable value is a standard deviation value, and spectral analysis is performed in advance to obtain the average vibration strength at each frequency and the standard deviation value. A high-fluidity concrete quality control system, characterized by monitoring whether or not it is within the range and monitoring abnormalities related to the mixing of high-fluidity concrete.