JP2000025029A - Quality controlling method for ready-mixed concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quality controlling method for ready-mixed concrete by which W/C (water cement ratio) of produced ready-mixed concrete can be grasped at real time in a point of time for production. SOLUTION: The set-up weighing value of various concrete materials is set up in accordance with a compounding ratio preset on an operation panel and respective materials are weighed while keeping the set-up weighing value as a target value. When discharge of the materials into a mixer is started, actually weighed amount of cement, weighed amount of water and surface water rate of aggregate are fetched from the operation panel 1 to a quality controlling device and simultaneously the set-up weighing value is fetched. Actual result W/C (water cement ratio) is calculated at real time from the weighed amount of cement, weighed amount of water and weight of surface water stuck on the surface of aggregate. W/C error at every kneading batch, which is difference value of the actual result W/C and set-up W/C calculated similarly from the set-up weighing value, is calculated. The W/C error is plotted in a CRT indicator at every kneading batch and transition of the W/C error is indicated in a graph.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for managing quality of ready-mixed concrete, and more particularly to a quality control method for displaying data on W / C of ready-mixed concrete to be manufactured.

[0002]

2. Description of the Related Art Conventionally, in a ready-mixed concrete manufacturing plant, as a quality control of a ready-mixed concrete, a sample is prepared by sampling a part of the ready-mixed concrete at the time of placing the concrete, and the test sample is prepared after 28 days. Data is collected by performing various tests such as compressive strength tests, and these data are sequentially input to a quality control device equipped with quality control software on a personal computer, for example, to output a strength test result report or Further, a predetermined number of data is statistically totalized, and the degree of variation in compressive strength is represented by a control chart or the like, so that the quality of the ready-mixed concrete manufactured and shipped is managed and fed back to the mix design.

Recently, the unit water volume has been increased to 185 kg.
/ M ³ or less, and the quality control audit system promotes quality improvement. Therefore, W / C ( (Water-cement ratio) is becoming increasingly important.

[0004]

However, in the above-mentioned conventional quality control method, samples are manufactured by sampling when ready-mixed concrete is manufactured and shipped, and after 28 days, various tests such as compressive strength are performed on the samples. And collects various quality data, inputs the data to a quality control device, and statistically analyzes them to verify the quality of the ready-mixed concrete and feeds the data back to the mix design. Therefore, there has been no one that can determine in real time whether the ready-mixed concrete has the W / C as designed when the ready-mixed concrete is manufactured.

[0005] In view of the above, it is an object of the present invention to provide a quality control method for ready-mixed concrete that enables real-time determination of the W / C of the manufactured ready-mixed concrete at the time of manufacture.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention sets a set weighing value of various concrete materials on an operation panel based on a predetermined blending value, and sets the set weighing value to a target value. When various materials are measured as values and kneaded with a mixer, the actual W / C (water-cement ratio) is calculated from the actually measured amount of cement, the amount of measured water, and the amount of surface water adhering to the surface of the measured aggregate. It calculates in real time, and further calculates the W / C error for each kneading batch, which is the difference between the actual W / C and the set W / C calculated from the set weighing value. It is characterized in that the transition of the error is graphically displayed on a display device.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the quality control method for ready-mixed concrete according to the present invention, a set weighing value based on a blended value of each material of ready-mixed concrete to be shipped to an operation panel for operating a ready-mixed concrete production plant is determined. Set and start weighing. At this time, it is necessary to consider the amount of surface water adhering to the aggregate, especially the surface of the sand, and the surface water amount of this sand is calculated based on the surface water content of the sand detected by the moisture meter installed in the sand flow path, Gravel, sand, and water are measured based on the set measurement value in consideration of the surface water amount, and also the cement and the admixture are measured. When the measurement of the various materials is completed, these materials are discharged to the mixer at predetermined time intervals and kneaded for a predetermined time to produce ready-mixed concrete.

During this time, the actual W / C is calculated from the actually measured cement amount, the measured water amount and the surface water amount of the aggregate calculated from the surface water ratio. Further, the setting W / C is calculated from the set weighing value of each material, and the difference between the setting W / C and the actual W / C, that is, the W / C error is calculated. Then, the W / C error is plotted for each kneading batch on a CRT display device as a display device, and the plots are connected by a line to be displayed as a graph showing the transition of the W / C error for each kneading batch.

[0009]

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

In the figure, reference numeral 1 denotes an operation panel for operating a ready-mixed concrete production plant, which includes a gravel measuring tank 2, a sand measuring tank 3,
A moisture meter 7 for taking in the measuring signals from the water measuring tank 4, the cement measuring tank 5, and the admixture measuring tank 6, and measuring the surface water content of the gravel and sand to be discharged to the gravel measuring tank 2 and the sand measuring tank 3. , 7 'can be taken in. At this time, if the surface water content is stable due to gravel or the like, the surface water content measured in the test room can be directly input to the operation panel 1 without using the moisture meter 7 '.

In the operation panel 1, when the concrete material is weighed, a set weighing value serving as a weighing target value for each material is set based on a predetermined mixing value of the concrete material.

Reference numeral 8 denotes an example of a quality control device, which comprises a CRT display device 10 for displaying various data on a personal computer main body 9, a printer 11 for outputting various data, and a personal computer main body 9. Has installed software for quality control of ready-mixed concrete.

As shown in FIG. 2, in the quality control device 8, the set weighing values set by the operation panel 1, the actual weighing values of the weighed various materials, and the surface water rates of the moisture meters 7, 7 'are real-time. It is received in real time by the processing unit 12, and the ratio of water / cement W /
C is calculated, and W / C is a difference value between the set W / C based on the set weighing value and the actual W / C based on the actual weighing value.
Calculate the C error. Then, these data are stored in the weighing result database file 13, and for the current day, the current day is extracted from the weighing result database file 13 into the weighing result file 14 on the day and displayed on the CRT display device 10, or is displayed on the printer 11. Output.

Next, a procedure for displaying the W / C error of the ready-mixed concrete manufactured at the time of the ready-mixed concrete on the display device of the quality control device will be described.

First, when the kind of ready-mixed concrete to be manufactured and the kneading amount are determined, a set weighing value, which is a weighing target value for each material, is set and input to the operation panel 1 based on the blending value determined for each kind.

When the weighing start operation is performed, the water content of the aggregate is measured by the moisture meters 7, 7 ', and the set weighing values of the aggregate and the weighing water in consideration of the measured surface water content are calculated. Is reset.

When the weighing of each material is completed with the set weighing value as a target value, the weighing value and the surface water rate at the time of weighing are taken into the quality control device 8, and the release of the weighed material to the mixer is started. The W / C error of the ready-mixed concrete of this batch is calculated.

First, the setting W / C is calculated as follows from the set weighing value based on a predetermined blending value. Among the mixing values, the mixing values of sand, kneading water and cement are, for example, sand S1 = 500 kg kneading water W1 = 300 kg cement C1 = 700 kg, and the surface water ratio SC of the sand is: surface water ratio SC = 10% If so, the set weighed value is calculated as follows: Sand set weighed value S2 = 500 × (1 + 10/100) = 5
50kg surface water amount of sand w1 = 500 × (10/100) = 50k
g Water setting measurement value W2 = 300-50 = 250 kg Setting W / C is as follows: Setting W / C = (250 + 50) /700=42.86%.

Next, when the actual W / C is obtained, for example, assuming that the actual measured value with respect to the set measured value is sand S3 = 552 kg water W3 = 251 kg cement C3 = 702 kg, the surface water amount w2 in the measured sand S3 Is the surface water amount w2 = 552 × (10/100) = 52 kg, and the total water amount W4 of the measured water W3 and the surface water amount w2 is the total water amount W4 = 251 + 52 = 303 kg. Therefore, the actual W / C is actual W / C = 303/702 = 43.16%.

Next, the set W / C (%) and the actual W / C
When the W / C error is calculated from the difference value with respect to (%), W / C error = set W / C (%) − actual W / C (%) = 43.16−42.86 = 0.3% Becomes

W / C calculated for each batch in this way
The errors are plotted from left to right in the order of batch numbers on the screen of the CRT display device 10 of the quality control device 11 as shown in FIG.
A line graph showing the transition of the / C error is displayed.

The W / C error display screen shown in FIG. 3 has a vertical line representing W / C error%, a horizontal line representing a batch number, and a reference line CL drawn horizontally near the center of the vertical line. An upper limit W / C error line UL is drawn above and a lower limit W / C error line LL is drawn below to make it easy to determine whether the plotted W / C error is within an allowable range. At this time, the scale is automatically adjusted so that UL and LL are located at two-thirds of the scale width above and below the reference line CL on the vertical axis.

Further, a scroll bar A is provided below the horizontal line, and when the scroll bar A is slid left and right, the graph of the W / C error on the screen scrolls left and right, and the W / C error of the desired batch number is displayed. The graph can be viewed immediately.

As described above, the W / C error can be graphically displayed in real time at the time of manufacturing on the CRT display device 10 of the quality control device 8, and it is easy to determine whether the W / C as designed is obtained. Quality control of W / C of ready-mixed concrete becomes easy, and if the W / C is managed as designed, the compressive strength of the ready-mixed concrete manufactured from the W / C after 28 days can be easily estimated. You can also.

The weighing results can be displayed as a list from the weighing results database file 13 and the weighing results file 14 shown in FIG.
1, the W / C error, the set W / C and the actual W / C
A list of C and weighing results can be output, and daily weighing data and a change state of W / C can be confirmed, and quality control can be performed finely.

In this embodiment, the quality control device has been described as being independent from the operation panel. However, it goes without saying that the quality control device can be incorporated in the operation panel.

[0027]

As described above, according to the method for quality control of ready-mixed concrete according to the present invention, each material is weighed with the set weighing value of various concrete materials set on the operation panel as a target value, and the measured value is measured by a mixer. At the time of kneading, the actual W / C (water-cement ratio) is calculated in real time from the actually measured amount of cement, the measured amount of water, and the measured amount of surface water adhering to the surface of the aggregate. Since the W / C error for each kneading batch, which is the difference value from the set W / C calculated from the set weighing value, was calculated, and the transition of the W / C error for each kneading batch was graphically displayed on a display device. It is possible to grasp whether the W / C of the ready-mixed concrete manufactured in real time at the time of the production of the ready-mixed concrete is the W / C as designed, and to perform more complete quality control in addition to the conventional quality control method.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a quality control device adopting a ready-mixed concrete quality control method according to the present invention.

FIG. 2 is an explanatory diagram showing a data processing flow.

FIG. 3 is an explanatory diagram showing a configuration of a screen.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Operation panel 2 ... Gravel measuring tank 3 ... Sand measuring tank 4 ... Water measuring tank 5 ... Cement measuring tank 6 ... Admixture measuring tank 7, 7 '... Moisture meter 8 ... Quality control device 9 ... Personal computer main body 10 ... CRT Display device 11: Printer CL: Reference line UL: Upper limit W
/ C error line LL: Lower limit W / C error line A: Scroll bar

Claims (1)

[Claims] 1. A set measurement value of various concrete materials is set on an operation panel based on a predetermined blending value, and various materials are measured using the set measurement value as a target value, and are kneaded by a mixer. The actual W / C (water-cement ratio) is calculated in real time from the actually measured cement amount, the measured water amount, and the measured surface water amount adhering to the surface of the aggregate,
Further, a setting W calculated from the actual W / C and the set weighing value.
/ C calculated by calculating a W / C error for each kneading batch, which is a difference value amount with respect to / C, and displaying a transition of the W / C error for each kneading batch on a display device in a graph. Quality control method.