Measurement method for concrete equivalent to blast furnace cement type A

Abstract

To obtain highly reliable and objective mass measurement values about each of Portland cement and a blast furnace cement type B even in a production facility only provided with one cement measuring instrument.SOLUTION: In a measurement method for producing concrete equivalent to a blast furnace cement type A by kneading Portland cement, a blast furnace cement type B, an aggregate, water and a chemical admixture by a mixer, the following step S1 and step 2 are executed. In the step S1, either the Portland cement or the blast furnace cement type B is measured by a cement measuring instrument so as to be fed to the mixer. Thereafter, in the step S2, the other of the Portland cement and the blast furnace cement type B is measured by the same cement measuring instrument so as to be fed to the mixer.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for measuring Portland cement and blast-furnace cement type B in order to produce concrete equivalent to blast-furnace cement type A by kneading Portland cement, blast-furnace cement type B, aggregate, water, and a chemical admixture together.

Background Art

[0002] As cement, there are Portland cement (e.g., ordinary Portland cement) and blast-furnace cement. Portland cement is the most typical type of cement obtained by firing limestone, clay, etc. and adding gypsum to make it powdery. Blast-furnace cement is a cement obtained by mixing blast-furnace slag with Portland cement, and it has low heat generation due to hydration and high chemical resistance.

[0003] As blast-furnace cement, there are blast-furnace cement type A, blast-furnace cement type B, and blast-furnace cement type C. In blast-furnace cement type A, the mass ratio of blast-furnace slag exceeds 5% and is 30% or less; in blast-furnace cement type B, the mass ratio of blast-furnace slag exceeds 30% and is 60% or less; in blast-furnace cement type C, the mass ratio of blast-furnace slag exceeds 60% and is 70% or less.

[0004] A technique for producing concrete equivalent to blast-furnace cement type A by kneading Portland cement, blast-furnace cement type B, aggregate, water, and a chemical admixture in a mixer is disclosed in Patent Document 1. This concrete equivalent to blast-furnace cement type A has performance equivalent to general concrete and can reduce the carbon dioxide emissions from concrete materials by 8.2 to 18.5%.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] To produce concrete equivalent to the aforementioned blast furnace cement type A, it is necessary to weigh Portland cement and blast furnace cement type B separately and supply them to the mixer. When weighing these two types of cement in a ready-mix concrete manufacturing facility that has only one cement weighing scale, cumulative weighing has traditionally been performed.

[0007] In other words, one type of cement is weighed out using a cement weighing scale in an amount equal to its target mass (referred to as the first target mass). Next, the other type of cement is added to the same cement weighing scale, so the total mass of cement (the first target mass plus the target mass of the other type of cement) is weighed out using the same scale. In this type of cumulative weighing, since each type of cement is weighed out using a single scale, it is difficult to show the breakdown of the masses of the two types of cement weighed out as reliable and objective evidence. Furthermore, there is a high possibility of errors occurring in the measured mass values.

[0008] Therefore, the object of the present invention is to provide a weighing method and weighing apparatus that enable reliable and objective mass measurements to be obtained for both Portland cement and blast furnace cement type B, even in a ready-mix concrete manufacturing facility equipped with only one cement weighing device. [Means for solving the problem]

[0009] To achieve the above-mentioned objective, the weighing method according to the present invention is a weighing method for producing concrete equivalent to blast furnace cement type A by mixing Portland cement, blast furnace cement type B, aggregate, water, and chemical admixture in a mixer, (A) Either the Portland cement or the blast furnace cement type B is measured using a cement weighing device and supplied to the mixer. (B) Subsequently, the Portland cement and the other type of blast furnace cement B are measured using the same cement measuring device and supplied to the mixer.

[0010] The weighing device according to the present invention is a weighing device for producing concrete equivalent to blast furnace cement type A by mixing Portland cement, blast furnace cement type B, aggregate, water, and chemical admixture in a mixer, The system is equipped with a cement measuring device, which measures out one of the Portland cement and the blast furnace cement type B using the cement measuring device and supplies it to the mixer, and then measures out the other of the Portland cement and the blast furnace cement type B using the same cement measuring device and supplies it to the mixer. [Effects of the Invention]

[0011] According to the present invention, highly reliable and objective mass measurements can be obtained for both Portland cement and blast furnace cement type B. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a concrete manufacturing apparatus equipped with a weighing device according to an embodiment of the present invention. [Figure 2] An example of a weighing method according to an embodiment of the present invention is shown. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described based on the drawings. Common parts in each figure are denoted by the same reference numerals, and redundant explanations are omitted.

[0014] Figure 1 is a schematic diagram of a concrete manufacturing apparatus 10 according to an embodiment of the present invention. The manufacturing apparatus 10 is a device for controlling the quality of concrete equivalent to blast furnace cement type A. Concrete equivalent to blast furnace cement type A is ready-mixed concrete produced by mixing Portland cement, blast furnace cement type B, aggregate (fine aggregate and coarse aggregate), water, and chemical admixtures. Such concrete equivalent to blast furnace cement type A will be simply referred to as "type A equivalent concrete" below.

[0015] In concrete equivalent to Type A, the mass ratio of blast furnace slag to the combined amount of Portland cement and blast furnace cement Type B (excluding water, aggregates, and chemical admixtures) is greater than 5% and less than or equal to 30%. The mass ratio of blast furnace slag is the ratio of the mass of blast furnace slag contained in the target cement (i.e., Portland cement and blast furnace cement Type B in ready-mixed concrete) to the total mass (excluding water, aggregates, etc.) of the target cement (the same applies hereafter). Furthermore, in this application, if a and b are numerical values ​​and the statement is made that "the mass ratio is a% to b%", the range indicated by "a% to b%" may or may not include a%, and may or may not include b%.

[0016] The concrete manufacturing apparatus 10 may be installed in a ready-mix concrete manufacturing facility. This manufacturing facility may be, but is not limited to, a ready-mix concrete manufacturing plant (ready-mix concrete plant) located on land. For example, this manufacturing facility may be installed on a ship. The concrete manufacturing apparatus 10 comprises a weighing device 3 and a mixer 5.

[0017] The weighing device 3 weighs Portland cement and blast furnace cement type B in two stages using a single cement weighing device 21. Specifically, the weighing device 3 weighs one of the Portland cement and blast furnace cement type B using the cement weighing device 21 and supplies it to the mixer 5, and then weighs the other of the Portland cement and blast furnace cement type B using the same cement weighing device 21 and supplies it to the mixer 5.

[0018] According to this embodiment, when weighing Portland cement, the weighing device 3 automatically weighs Portland cement so that its mass is the target mass, and when weighing blast furnace cement type B, it automatically weighs blast furnace cement type B so that its mass is the target mass.

[0019] The target mass of Portland cement and the target mass of blast furnace cement type B are determined based on the predetermined mixing ratio of Portland cement and blast furnace cement type B, the target mass of the entire amount of concrete equivalent to type A to be manufactured, and the like. The predetermined mixing ratio is predetermined so that the mass ratio of blast furnace slag in the concrete equivalent to type A to be manufactured exceeds 5% and is 30% or less as described above. The predetermined mixing ratio will be described later.

[0020] In addition, the measuring device 3 may be configured to automatically measure the aggregates. When fine aggregates and coarse aggregates are used as the aggregates, the measuring device 3 automatically measures the fine aggregates so that their mass becomes the target mass of the fine aggregates, and automatically measures the coarse aggregates so that their mass becomes the target mass of the coarse aggregates.

[0021] Furthermore, the measuring device 3 may be configured to automatically measure the chemical admixture so that its mass becomes the target mass of the admixture, and to automatically measure the liquid obtained by combining water and the chemical admixture so that its mass becomes the target mass of the water. The target mass of the fine aggregates, the target mass of the coarse aggregates, the target mass of the admixture, and the target mass of the water may be determined based on, for example, the target mass of the entire amount of concrete equivalent to type A to be manufactured.

[0022] <Details of the configuration of the measuring device> The measuring device 3 includes a first supply device 11, a second supply device 12, a cement measuring device 21, a fine aggregate supply device 13X, a fine aggregate measuring device 23X, a coarse aggregate supply device 13Y, a coarse aggregate measuring device 23Y, an admixture supply device 14, a water supply device 15, a liquid measuring device 24 for the admixture and water, a control unit 31, and a storage device 33.

[0023] The first supply device 11 supplies Portland cement to the cement measuring device 21. The first supply device 11 has a storage bottle 11a and an opening / closing gate 11b. The storage bottle 11a holds a sufficient amount of Portland cement inside. The Portland cement in the storage bottle 11a may be transported from the cement silo of the ready-mix concrete plant. The opening / closing gate 11b opens and closes an opening provided at the bottom of the storage bottle 11a. When the opening / closing gate 11b is opened, the Portland cement falls from the storage bottle 11a through the opening at its bottom (opening / closing gate 11b) into the cement measuring device 21. This supplies Portland cement to the cement measuring device 21 (measuring bottle 21a, described later).

[0024] The second supply device 12 supplies blast furnace cement type B to the cement measuring device 21. The second supply device 12 has a storage bottle 12a and an opening / closing gate 12b. The storage bottle 12a holds a sufficient amount of blast furnace cement type B inside. The blast furnace cement type B in the storage bottle 12a may be transported from the cement silo of the ready-mix concrete plant. The opening / closing gate 12b opens and closes an opening provided at the bottom of the storage bottle 12a. When the opening / closing gate 12b is opened, the blast furnace cement type B falls from the storage bottle 12a through the opening at its bottom (opening / closing gate 12b) into the cement measuring device 21. This supplies blast furnace cement type B to the cement measuring device 21 (measuring bottle 21a, described later).

[0025] The cement weighing device 21 is for weighing Portland cement and blast furnace cement type B in two stages. When weighing Portland cement, the cement weighing device 21 holds the Portland cement supplied from the first supply device 11, measures the mass of the Portland cement it holds, and outputs the measured mass value to the control unit 31. When weighing blast furnace cement type B, the cement weighing device 21 holds the blast furnace cement type B supplied from the second supply device 12, measures the mass of the blast furnace cement type B it holds, and outputs the measured mass value to the control unit 31.

[0026] The cement measuring device 21 includes a measuring bottle 21a, a load cell 21b, and an opening / closing gate 21c.

[0027] The measuring bottle 21a is supported (e.g., suspended) by a structure via a load cell 21b. Portland cement or blast furnace cement type B (hereinafter, Portland cement or blast furnace cement type B will also be simply referred to as cement) is supplied to the measuring bottle 21a from the first supply device 11 or the second supply device 12. As a result, the measuring bottle 21a holds the cement inside. The load cell 21b measures the mass of the cement held by the measuring bottle 21a and outputs the measured mass value to the control unit 31. The opening / closing gate 21c opens and closes an opening provided at the bottom of the measuring bottle 21a. When the opening / closing gate 21c is opened, cement falls from the measuring bottle 21a through the opening at its bottom (opening / closing gate 21c) into the mixer 5. As a result, cement is supplied to the mixer 5.

[0028] The fine aggregate supply device 13X supplies fine aggregate to the fine aggregate weighing device 23X. The fine aggregate supply device 13X has a storage jar 13a and an opening / closing gate 13b. The storage jar 13a holds a sufficient amount of fine aggregate inside. The fine aggregate in the storage jar 13a may be transported from the aggregate storage area of ​​the ready-mix concrete plant. The opening / closing gate 13b opens and closes an opening provided at the bottom of the storage jar 13a. When the opening / closing gate 13b is opened, the fine aggregate falls from the storage jar 13a through the opening at its bottom (opening / closing gate 13b) into the fine aggregate weighing device 23X. This supplies fine aggregate to the fine aggregate weighing device 23X (the weighing jar 23a described later).

[0029] The fine aggregate weighing device 23X holds the fine aggregate supplied from the fine aggregate supply device 13X, measures the mass of the held fine aggregate, and outputs the measured mass value to the control unit 31. The fine aggregate weighing device 23X includes a weighing bottle 23a, a load cell 23b, and an opening / closing gate 23c.

[0030] The weighing bottle 23a is supported (e.g., suspended) by a structure via a load cell 23b. The weighing bottle 23a holds the fine aggregate supplied from the fine aggregate supply device 13X inside. The load cell 23b measures the mass of the fine aggregate held by the weighing bottle 23a and outputs the measured mass value to the control unit 31. The opening / closing gate 23c opens and closes an opening provided at the bottom of the weighing bottle 23a. When the opening / closing gate 23c is opened, the fine aggregate falls from the weighing bottle 23a through the opening at its bottom (opening / closing gate 23c) into the mixer 5. This supplies the fine aggregate to the mixer 5.

[0031] The coarse aggregate supply device 13Y supplies coarse aggregate to the coarse aggregate weighing device 23Y. The configuration and operation of the coarse aggregate supply device 13Y and the coarse aggregate weighing device 23Y are the same as those of the fine aggregate supply device 13X and the fine aggregate weighing device 23X, so their explanation is omitted. In other words, the configuration and operation of the coarse aggregate supply device 13Y and the coarse aggregate weighing device 23Y are the same as described above, except that the fine aggregate supply device 13X, the fine aggregate weighing device 23X, and the fine aggregate are replaced with the coarse aggregate supply device 13Y, the coarse aggregate weighing device 23Y, and the coarse aggregate, respectively.

[0032] The admixture supply device 14 supplies liquid chemical admixture to the liquid measuring device 24. The admixture supply device 14 has a storage bottle 14a and a valve 14b. The storage bottle 14a holds a sufficient amount of chemical admixture inside. The valve 14b opens and closes an opening provided at the bottom of the storage bottle 14a. When the valve 14b is opened, the chemical admixture flows downward from the storage bottle 14a through the opening at its bottom (valve 14b) and is supplied to the liquid measuring device 24 (measuring bottle 24a, described later).

[0033] The water supply device 15 supplies water to the liquid measuring device 24. The water supply device 15 has a storage bottle 15a and a valve 15b. The storage bottle 15a holds a sufficient amount of water inside. The water in the storage bottle 15a may be supplied from, for example, an underground water tank installed in a ready-mix concrete plant, or it may be tap water, industrial water, recycled water, etc. The valve 15b opens and closes an opening provided at the bottom of the storage bottle 15a. When the valve 15b is opened, water flows downward from the storage bottle 15a through the opening at its bottom (valve 15b) and is supplied to the liquid measuring device 24 (measuring bottle 24a described later).

[0034] The liquid measuring device 24 holds the liquid (chemical admixture and water) supplied from the admixture supply device 14 and the water supply device 15, measures the mass of the held liquid, and outputs the measured mass value to the control unit 31. The liquid measuring device 24 includes a measuring bottle 24a, a load cell 24b, and a valve 24c.

[0035] The measuring bottle 24a is supported (e.g., suspended) by a structure via a load cell 24b. The measuring bottle 24a holds the liquid supplied from the admixture supply device 14 and the water supply device 15 inside. The load cell 24b measures the mass of the liquid held in the measuring bottle 24a and outputs the measured mass value to the control unit 31. The valve 24c opens and closes an opening provided at the bottom of the measuring bottle 24a. When the valve 24c is opened, the liquid (chemical admixture and water) flows downward from the measuring bottle 24a through the opening at its bottom (valve 24c) and is supplied to the mixer 5.

[0036] The control unit 31 may have pre-inputted or set the following: identification information for the concrete equivalent to type A to be manufactured, and the target mass of Portland cement, the target mass of blast furnace cement type B, the target mass of fine aggregate, the target mass of coarse aggregate, the target mass of admixture, and the target mass of water, as defined above.

[0037] The control unit 31 controls the first supply device 11, the second supply device 12, and the cement measuring device 21 so that one of the Portland cement and blast furnace cement type B is measured out by the cement measuring device 21 and supplied to the mixer 5, and then the other of the Portland cement and blast furnace cement type B is measured out by the same cement measuring device 21 and supplied to the mixer 5.

[0038] In this case, when weighing either Portland cement or blast furnace cement type B (hereinafter also referred to as "one type of cement") with the cement weighing device 21, the control unit 31 controls the first supply device 11 or the second supply device 12 that supplies the one type of cement so that the mass measurement value from the cement weighing device 21 becomes the target mass (hereinafter also referred to as the first target mass). As a result, the cement weighing device 21 holds a mass of one type of cement that is within an acceptable range of deviation from the target mass (hereinafter referred to as the state in which the one type of cement has been received).

[0039] Similarly, when weighing Portland cement and blast furnace cement type B (hereinafter also referred to as "the other cement") with the cement weighing device 21, the control unit 31 controls the first supply device 11 or the second supply device 12 that supplies the other cement so that the mass measured by the cement weighing device 21 equals the target mass (hereinafter also referred to as "the second target mass"). As a result, the cement weighing device 21 holds a mass of the other cement that is within an acceptable range of deviation from the target mass (hereinafter referred to as "the state in which the other cement has been received").

[0040] More specifically, when Portland cement is measured using the cement weighing device 21, the control unit 31 controls the opening and closing of the gate 11b based on the mass measurement from the cement weighing device 21 and the target mass of Portland cement. In this control, the control unit 31 opens the gate 11b of the first supply device 11 to start supplying Portland cement from the storage bottle 11a of the first supply device 11 to the weighing bottle 21a. When the mass measurement from the cement weighing device 21 approaches the target mass of Portland cement (for example, when the mass measurement from the cement weighing device 21 becomes a value smaller than the target mass by a set value), the gate 11b of the first supply device 11 may be closed. As a result, the cement weighing device 21 enters a state where it has completed receiving the Portland cement.

[0041] Similarly, when measuring blast furnace cement type B with the cement weighing device 21, the control unit 31 controls the opening and closing of the gate 12b based on the mass measurement from the cement weighing device 21 and the target mass of blast furnace cement type B. In this control, the control unit 31 opens the gate 12b of the second supply device 12 to start supplying blast furnace cement type B from the storage bottle 12a of the second supply device 12 to the weighing bottle 21a. When the mass measurement from the cement weighing device 21 approaches the target mass of blast furnace cement type B (for example, when the mass measurement from the cement weighing device 21 becomes a value smaller than the target mass by a set value), the gate 12b of the second supply device 12 may be closed. As a result, the cement weighing device 21 enters a state where it has completed receiving blast furnace cement type B.

[0042] The control unit 31 controls the fine aggregate supply device 13X based on the mass measurement value from the fine aggregate weighing device 23X and the target mass of the fine aggregate, so that the mass measurement value becomes the target mass of the fine aggregate. As a result, the fine aggregate weighing device 23X holds a mass of fine aggregate that is within an acceptable range of deviation from the target mass of the fine aggregate (hereinafter referred to as the fine aggregate acceptance completion state).

[0043] More specifically, the control unit 31 controls the opening and closing of the gate 13b based on the mass measurement value from the fine aggregate weighing unit 23X and the target mass of fine aggregate. In this control, the control unit 31 opens the gate 13b of the fine aggregate supply device 13X to start supplying aggregate from the storage bottle 13a to the weighing bottle 23a of the fine aggregate supply device 13X. When the mass measurement value from the fine aggregate weighing unit 23X approaches the target mass of fine aggregate (for example, when the mass measurement value from the fine aggregate weighing unit 23X becomes a value smaller than the target mass of fine aggregate by a set value), the control unit 31 may close the gate 13b of the fine aggregate supply device 13X. As a result, the fine aggregate weighing unit 23X enters a state where it has completed receiving the fine aggregate.

[0044] The control unit 31 controls the coarse aggregate supply device 13Y based on the mass measurement value from the coarse aggregate weighing device 23Y and the target mass of coarse aggregate, so that the mass measurement value becomes the target mass of coarse aggregate. As a result, the coarse aggregate weighing device 23Y holds a mass of coarse aggregate within an acceptable range of deviation from the target mass of coarse aggregate (hereinafter referred to as the coarse aggregate acceptance completion state). A more detailed explanation of this control is the same as in the case of fine aggregate, so it will be omitted.

[0045] The control unit 31 controls the admixture supply device 14 based on the mass measurement value from the liquid measuring device 24 and the target mass of the admixture, so that the mass measurement value becomes the target mass of the admixture. As a result, the liquid measuring device 24 holds a mass of chemical admixture that is within an acceptable range of deviation from the target mass of the admixture (hereinafter referred to as the chemical admixture acceptance completion state).

[0046] More specifically, the control unit 31 controls the opening and closing of the valve 14b of the admixture supply device 14 based on the mass measurement value from the liquid measuring device 24 and the target mass of the admixture. In this control, the control unit 31 opens the valve 14b to start supplying the chemical admixture from the storage bottle 14a to the measuring bottle 24a of the admixture supply device 14, and may close the valve 14b when the mass measurement value from the liquid measuring device 24 approaches the target mass of the admixture (for example, when the mass measurement value from the liquid measuring device 24 becomes a value smaller than the target mass of the admixture by a set value). As a result, the liquid measuring device 24 enters a state where it has completed receiving the chemical admixture.

[0047] Next, the control unit 31 controls the water supply device 15 to supply water to the liquid measuring device 24 holding the chemical admixture. For example, the control unit 31 controls the water supply device 15 based on the mass measurement value from the liquid measuring device 24 and the target water mass so that the mass measurement value becomes the target water mass. As a result, the liquid measuring device 24 is in a state where it holds a liquid (a mixture of the chemical admixture and water) whose mass is within an acceptable range from the target water mass (hereinafter referred to as the water reception completion state).

[0048] More specifically, the control unit 31 controls the opening and closing of the valve 15b of the water supply device 15 based on the mass measurement value from the liquid measuring device 24 and the target water mass. In this control, the control unit 31 opens the valve 15b to start supplying water from the storage bottle 15a to the measuring bottle 24a of the water supply device 15, and may close the valve 15b when the mass measurement value from the liquid measuring device 24 approaches the target water mass (for example, when the mass measurement value from the liquid measuring device 24 becomes a value smaller than the target water mass by a set value). As a result, the liquid measuring device 24 enters a state where water reception is complete.

[0049] The control unit 31 has an error calculation unit 31a that calculates the measurement error by the weighing device 3. The error calculation unit 31a may be incorporated into the control unit 31. Hereinafter, the mass measurements output from the cement weighing device 21, which has completed receiving one type of cement, the fine aggregate weighing device 23X, which has completed receiving the fine aggregate, and the coarse aggregate weighing device 23Y, which has completed receiving the coarse aggregate, will be referred to as the 1st to 3rd measurement values, respectively. Furthermore, hereinafter, the mass measurements output from the cement weighing device 21, which has completed receiving the other type of cement, the liquid weighing device 24, which has completed receiving the chemical admixture, and the liquid weighing device 24, which has completed receiving the water, will be referred to as the 4th to 6th measurement values, respectively.

[0050] The error calculation unit 31a calculates the errors between the first measured value and the target mass of one cement (first target mass), the second measured value and the target mass of fine aggregate, the third measured value and the target mass of coarse aggregate, the fourth measured value and the target mass of the other cement (second target mass), the fifth measured value and the target mass of admixture, and the sixth measured value and the target mass of water, as the first to sixth errors, respectively.

[0051] The first to sixth measurement values ​​and the first to sixth errors are recorded in the storage device 33 in association with the identification information of the Type A equivalent concrete being manufactured. That is, the error calculation unit 31a stores the first to sixth measurement values ​​and the first to sixth errors in the storage device 33 as quality data in association with the identification information of the Type A equivalent concrete being manufactured. At this time, the error calculation unit 31a may further store the first and second target masses, the target mass of fine aggregate, the target mass of coarse aggregate, the target mass of admixture, and the target mass of water in the storage device 33 in association with the said identification information. The storage device 33 may be a non-volatile memory. For example, the storage device 33 may be a flash memory, a magnetic disk (hard disk), or an optical disk.

[0052] The control unit 31 may, as described above, once the cement measuring device 21 has completed receiving one type of cement, (for example, by opening the gate 21c) supply one type of cement from the cement measuring device 21 to the mixer 5, and then, as described above, set the cement measuring device 21 to complete receiving the other type of cement, and then (for example, by opening the gate 21c) supply the other type of cement from the cement measuring device 21 to the mixer 5.

[0053] Furthermore, the control unit 31 may also perform the following control to supply other materials to the mixer 5.

[0054] The control unit 31 may, when the fine aggregate weighing unit 23X is in the state where it has finished receiving the fine aggregate, control the unit to supply the fine aggregate from the fine aggregate weighing unit 23X to the mixer 5; when the coarse aggregate weighing unit 23Y is in the state where it has finished receiving the coarse aggregate, control the unit to supply the coarse aggregate from the coarse aggregate weighing unit 23Y to the mixer 5; and when the liquid weighing unit 24 is in the state where it has finished receiving the water, control the unit to supply the water from the liquid weighing unit 24 together with the chemical admixture to the mixer 5. In this case, the supply of fine aggregate from the fine aggregate weighing unit 23X to the mixer 5 is performed by the control unit 31 opening the on / off gate 23c of the fine aggregate weighing unit 23X, the supply of coarse aggregate from the coarse aggregate weighing unit 23Y to the mixer 5 is performed by the control unit 31 opening the on / off gate 23c of the coarse aggregate weighing unit 23Y, and the supply of water and chemical admixture from the liquid weighing unit 24 to the mixer 5 is performed by the control unit 31 opening the valve 24c of the liquid weighing unit 24.

[0055] The control unit 31 may operate the mixer 5 when manufacturing concrete equivalent to type A. For example, the control unit 31 may start the mixer 5 when it first supplies some of the materials used to manufacture concrete equivalent to type A (Portland cement, blast furnace cement type B, aggregate, and water and chemical admixture) to the mixer 5. Then, while the mixer 5 is operating, the control unit 31 supplies the remaining materials used to manufacture concrete equivalent to type A to the mixer 5. As a result, Portland cement, blast furnace cement type B, aggregate (fine aggregate and coarse aggregate), and water and chemical admixture are mixed in the mixer 5. Consequently, concrete equivalent to type A is manufactured by mixing Portland cement, blast furnace cement type B, aggregate, water and chemical admixture.

[0056] (Mixing ratio) The predetermined mixing ratio of Portland cement and blast furnace cement type B described above may be, for example, the mass ratio defined as follows:

[0057] Here, we assume that while it is known that the mass percentage of blast furnace slag in Portland cement is between 0% and 5%, it is difficult to determine which value it is within this range, and that while it is known that the mass percentage of blast furnace slag in blast furnace cement type B is between 40% and 45%, it is difficult to determine which value it is within this range. Under these assumptions, the mixing ratio of Portland cement and blast furnace cement may be predetermined according to Table 1.

[0058] [Table 1]

[0059] According to Table 1, the mixing ratios are determined as follows: When producing concrete equivalent to Type A with a blast furnace slag mass ratio of 8% to 13%, the mixing ratio of Portland cement and Type B blast furnace cement to be mixed together shall be set to 80.0:20.0. When producing concrete equivalent to Type A with a blast furnace slag mass ratio of 13% to 18%, the mixing ratio of Portland cement and Type B blast furnace cement to be mixed with each other shall be set to 67.5:32.5. When producing concrete equivalent to Type A with a blast furnace slag mass ratio of 18% to 23%, the mixing ratio of Portland cement and Type B blast furnace cement to be mixed with each other shall be set to 55.0:45.0.

[0060] (Tolerance for error) The above-mentioned tolerance range for the error (first error) between the measured mass value (first measurement value) of one of the measured cements (Portland cement or blast furnace cement type B) and the first target mass is, for example, from zero to ±1% of the first target mass. That is, if the ratio of the absolute value of the first error (the value obtained by subtracting the first target mass from the first measurement value) to the first target mass is 1% or less, the first error is within the above tolerance range. Similarly, the permissible range for the error (fourth error) between the measured mass (fourth measurement) of the other cement (Portland cement or blast furnace cement type B) and the second target mass is, for example, from zero to ±1% of the second target mass.

[0061] The above-mentioned tolerance range for the error (second error) between the measured mass value of the fine aggregate (second measurement value) and the target mass of the fine aggregate is, for example, from zero to ±3% of the target mass of the fine aggregate. The above-mentioned permissible range for the error (third error) between the measured mass value of the weighed coarse aggregate (third measurement value) and the target mass of the coarse aggregate is, for example, from zero to ±3% of the target mass of the coarse aggregate.

[0062] The above-mentioned permissible range for the error (fifth error) between the measured mass of the chemical admixture (fifth measurement value) and the target mass of the admixture is, for example, from zero to ±3% of the target mass of the admixture. The above-mentioned permissible range for the error (sixth error) between the measured mass value (sixth measurement value) of the measured liquid (liquid containing water and chemical admixture) and the target water mass is, for example, from zero to ±1% of the target water mass. Furthermore, according to the present invention, each of the above-mentioned permissible ranges is not limited to the numerical examples described above.

[0063] (Method for weighing concrete equivalent to Type A) Figure 2 is a flowchart showing a weighing method for producing concrete equivalent to Type A according to an embodiment of the present invention. This weighing method may be performed using the weighing device 3 (manufacturing device 10) described above. The weighing method comprises steps S1 to S3.

[0064] In step S1, the identification information of the Type A equivalent concrete to be manufactured, the first and second target masses, the target mass of fine aggregate, the target mass of coarse aggregate, the target mass of admixture, and the target mass of water are input to the weighing device 3 (control unit 31). For example, this input may be made by a person operating an appropriate control unit (touch panel, keyboard, etc.). After this input is made, a weighing start command may be input to the weighing device 3 (control unit 31). This input may be made by a person operating an appropriate control unit.

[0065] Step S2 begins when a metering start command is input to the metering device 3 (control unit 31).

[0066] When starting Step 2, storage jars 11a, 12a, storage jar 13a for fine aggregate, storage jar 13a for coarse aggregate, storage jar 14a, and storage jar 15a may each contain sufficient amounts of Portland cement, blast furnace cement type B, fine aggregate, coarse aggregate, chemical admixture, and water, respectively. Here, storage jars 11a and 12a each contain Portland cement and blast furnace cement type B produced by the same producer. Furthermore, the Portland cement and blast furnace cement type B held in storage jars 11a and 12a, respectively, conform to their respective JIS standards.

[0067] Step S2 may be performed by the weighing device 3 based on the first and second target masses, the target mass of fine aggregate, the target mass of coarse aggregate, the target mass of admixture, and the target mass of water entered in step S1.

[0068] In step S2, the weighing device 3, as described above, automatically weighs one of the Portland cement and blast furnace cement type B using the cement weighing device 21 based on its target mass (first target mass) and supplies it to the mixer 5, and then weighs the other of the Portland cement and blast furnace cement type B using the same cement weighing device 21 based on its target mass (second target mass) and supplies it to the mixer 5.

[0069] Furthermore, in step S2, the weighing device 3 automatically weighs out the fine aggregate and coarse aggregate using the fine aggregate weighing device 23X and the coarse aggregate weighing device 23Y, respectively, based on the target mass of the fine aggregate and the target mass of the coarse aggregate, as described above. In step S2, the weighing device 3 supplies the fine aggregate and coarse aggregate thus weighed out from the fine aggregate weighing device 23X and the coarse aggregate weighing device 23Y, respectively, to the mixer 5, as described above.

[0070] Furthermore, as described above, the weighing device 3 automatically weighs the chemical admixture and water using the liquid measuring device 24 based on the target mass of the admixture and the target mass of the water, respectively. In step S2, the weighing device 3 supplies the chemical admixture and water thus weighed from the liquid measuring device 24 to the mixer 5 as described above.

[0071] Furthermore, in step S2, the weighing device 3 calculates the mass measurement value of one of the measured cements, its error (first error), the mass measurement value of the other measured cement, and its error (fourth error) as described above, and stores them in the storage device 33 in association with the identification information input in step S1.

[0072] Furthermore, in step S2, the weighing device 3 calculates the measured mass of the weighed fine aggregate, its error (second error), the measured mass of the weighed coarse aggregate, its error (third error), the measured mass of the weighed chemical admixture, its error (fifth error), the measured mass of the weighed water (more precisely, a mixture of chemical admixture and water), and its error (sixth error) as described above, and stores them in the storage device 33 in association with the identification information input in step S1.

[0073] The following describes a specific example of step S2. In this example, step S2 has two stages, as shown in Figure 2. The first stage consists of steps S20 to S24, and the second stage consists of steps S25 to S29.

[0074] <Stage 1> In step S20, the weighing device 3 sets the cement weigher 21 to the state where it has completed receiving one type of cement (Portland cement or blast furnace cement B), as described above, and sets the fine aggregate weigher 23X and the coarse aggregate weigher 23Y to the state where they have completed receiving fine aggregate and coarse aggregate, respectively. In one example, in step S20, the weighing device 3 sets the cement weigher 21 to the state where it has completed receiving Portland cement.

[0075] In step S21, the weighing device 3 (error calculation unit 31a) calculates the error (first error) between the weighed value (first weighed value) output from the cement weighing device 21, which has completed receiving one of the cements in step S20, and the target mass (first target mass) of the other cement.

[0076] Furthermore, in step S21, the weighing device 3 (error calculation unit 31a) calculates the error (second error) between the weighed value (second weighed value) output from the fine aggregate weigher 23X, which has reached the acceptance completion state in step S20, and the target mass of the fine aggregate. Similarly, in step S21, the weighing device 3 (error calculation unit 31a) calculates the error (third error) between the weighed value (third weighed value) output from the coarse aggregate weigher 23Y, which has reached the acceptance completion state in step S20, and the target mass of the coarse aggregate.

[0077] In step S22, it is checked whether the first error calculated in step S21 is within the acceptable range. If the first error is outside the acceptable range, the subsequent processing is stopped.

[0078] On the other hand, if the first error is within its allowable range, the process may proceed to step S23. Furthermore, if both the second and third errors (or one of the second and third errors) are within their allowable range, the process may proceed to step S23. In other words, in step S22, it may be checked whether the first to third errors (or a combination of the first error and one of the second and third errors) are within their respective allowable ranges.

[0079] Step S22 may be performed by the control unit 31 as follows: The control unit 31 determines whether the first error (or each of the first to third errors, or each of the first error and either the second or third error) is within the acceptable range. If the result of this determination is positive, the control unit 31 executes the processes from step S23 onward. On the other hand, if the result of this determination is negative, the control unit 31 outputs an error signal to that effect and does not execute the processes from step S23 onward. This error signal is output to, for example, an appropriate display, which then displays that the error is not within the acceptable range. In this case, the weighing device 3 may be inspected and adjusted by a person.

[0080] Alternatively, the weighing device 3 (error calculation unit 31a) inputs the first error (or each of the first to third errors, or each of the first error and either the second or third error) to the display. The display then shows the input error. If the person determines that the error displayed on the display is within the acceptable range, they input a command to the control unit 31 to execute the process from step S23 onwards by operating the appropriate control unit. The control unit 31 then executes the process from step S23 onwards. On the other hand, if the person determines that the error displayed on the display is outside the acceptable range, they do not input a command to the control unit 31 to execute the process from step S23 onwards. In this case, they may perform inspection, adjustment, etc. of the weighing device 3.

[0081] In step S23, the weighing device 3 (control unit 31) stores the first to third weighing values ​​and the first to third errors, along with the first target mass, fine aggregate target mass, and coarse aggregate target mass input in step S1, in the storage device 33 as quality data, in association with the identification information input in step S1. This quality data may be stored in the storage device 33.

[0082] In step S24, the cement weighing device 21, the fine aggregate weighing device 23X, and the coarse aggregate weighing device 23Y are supplied to the mixer 5, respectively. This supply may be achieved by the control unit 31 controlling the opening and closing gates 21c, 23c, and 23c of the cement weighing device 21, the fine aggregate weighing device 23X, and the coarse aggregate weighing device 23Y. At the start of this supply, the control unit 31 may start the operation of the mixer 5.

[0083] In one example, one of the cements is Portland cement, and in step S24, the Portland cement is supplied (put in) from the cement weighing device 21 to the mixer 5, and at the same time, the fine aggregate (sand) measured by the fine aggregate weighing device 23X is supplied (put in) to the mixer 5. At this time, the Portland cement and fine aggregate may be put into the mixer 5 in such a way that they mix together.

[0084] <Stage 2> In step S25, the weighing device 3 sets the cement weighing device 21 to the state where it has completed receiving the other cement (Portland cement or blast furnace cement B) as described above. Also in step S25, the weighing device 3 sets the liquid weighing device 24 to the state where it has completed receiving the chemical admixture, and then sets the liquid weighing device 24 to the state where it has completed receiving water (more precisely, a mixture of chemical admixture and water) as described above.

[0085] In step S26, the weighing device 3 (error calculation unit 31a) calculates the error (fourth error) between the weighed value (fourth weighed value) output from the cement weighing device 21, which has completed receiving the other cement in step S25, and the target mass (second target mass) of the other cement.

[0086] Furthermore, in step S26, the weighing device 3 (error calculation unit 31a) calculates the error (fifth error) between the measured value (fifth measured value) output from the liquid measuring device 24, which has completed receiving the chemical admixture in step S25, and the target mass of the admixture. Similarly, in step S26, the weighing device 3 (error calculation unit 31a) calculates the error (sixth error) between the measured value (sixth measured value) output from the liquid measuring device 24, which has completed receiving the water in step S25, and the target mass of water.

[0087] In step S27, it is checked whether the fourth error calculated in step S26 is within the acceptable range. If the fourth error is outside the acceptable range, the subsequent processing is stopped.

[0088] On the other hand, if the fourth error is within its allowable range, the process may proceed to step S28. Furthermore, if both the fifth and sixth errors (or one of the fifth and sixth errors) are within their allowable range, the process may proceed to step S28. In other words, in step S27, it may be checked whether the fourth to sixth errors (or a combination of the fourth error and one of the fifth and sixth errors) are within their respective allowable ranges.

[0089] Step S27 may be performed by the control unit 31 as follows: The control unit 31 determines whether the fourth error (or each of the fourth to sixth errors, or each of the fourth error and either the fifth or sixth error) is within the acceptable range. If the result of this determination is positive, the control unit 31 executes the processes from step S28 onward. On the other hand, if the result of this determination is negative, the control unit 31 outputs an error signal to that effect and does not execute the processes from step S28 onward. This error signal is output to, for example, an appropriate display, which then displays that the error is not within the acceptable range. In this case, the weighing device 3 may be inspected and adjusted by a person.

[0090] Alternatively, the weighing device 3 (error calculation unit 31a) inputs the fourth error (or each of the fourth to sixth errors, or the fourth error and each of the fifth and sixth errors) to the display. The display then shows the input error. If the person determines that the error displayed on the display is within the acceptable range, they input a command to the control unit 31 to execute the process from step S28 onwards by operating the appropriate control unit. The control unit 31 then executes the process from step S28 onwards. On the other hand, if the person determines that the error displayed on the display is outside the acceptable range, they do not input a command to the control unit 31 to execute the process from step S28 onwards. In this case, they may inspect or adjust the weighing device 3.

[0091] In step S28, the weighing device 3 (control unit 31) stores the fourth to sixth weighing values ​​and errors of the fourth to sixth, along with the second target mass, admixture target mass, and water target mass input in step S1, in the storage device 33, in association with the identification information input in step S1. As a result of performing step S28 and the above-described step S23, the storage device 33 stores the first to sixth weighing values, errors of the first to sixth, first and second target masses, fine aggregate target mass, coarse aggregate target mass, admixture target mass, and water target mass as quality data, in association with the identification information input in step S1.

[0092] In step S29, the cement measuring device 21 and the liquid measuring device 24 supply the other cement, chemical admixture, and water to the mixer 5, respectively. This supply may be achieved by the control unit 31 controlling the opening and closing gates 21c of the cement measuring device 21 and the valve 24c of the liquid measuring device 24.

[0093] In step S3, the mixer 5, which has been operating since step S24, mixes the Portland cement, blast furnace cement type B, coarse aggregate, fine aggregate, chemical admixture, and water supplied in steps S24 and S29 to produce concrete equivalent to type A.

[0094] As a result of steps S23 and S28, the quality data stored in the storage device 33 can be output to a display or printer as needed. In this case, the output quality data is displayed on the display or printed on paper by the printer.

[0095] (Effects of the embodiment) In this embodiment, a two-stage weighing process is performed in which one of Portland cement and blast furnace cement type B is weighed and supplied to the mixer 5, and then the other is weighed. In this way, Portland cement is weighed and its mass is measured while only Portland cement is held in the cement weighing device 21, and blast furnace cement type B is weighed and its mass is measured while only blast furnace cement type B is held in the cement weighing device 21. Therefore, highly reliable and objective mass measurements can be obtained for both Portland cement and blast furnace cement type B.

[0096] Furthermore, according to this embodiment, the masses of Portland cement and blast furnace cement type B used in the production of concrete equivalent to blast furnace cement type A are measured, and the measured masses are recorded in the storage device 33 as quality data, associated with the identification information of the produced type A equivalent concrete. Therefore, the recorded quality data can guarantee that the type A equivalent concrete was produced according to a predetermined mixing ratio of Portland cement and blast furnace cement type B. As a result, the required performance of the concrete can be guaranteed. For example, after producing type A equivalent concrete, its quality can be confirmed using the above quality data and shown to a third party.

[0097] Furthermore, Portland cement and blast furnace cement type B are weighed individually using a two-stage weighing method, as described above, rather than cumulative weighing. This allows for obtaining separate mass measurements for Portland cement and blast furnace cement type B. Therefore, these mass measurements can be presented as highly reliable and objective quality data (evidence).

[0098] On the other hand, unlike this embodiment, in the case of cumulative weighing, first, a predetermined target mass of Portland cement is weighed out using a weighing instrument. Next, by adding a predetermined type B blast furnace cement to the same weighing instrument, the total mass of cement, which is the sum of the target mass of Portland cement and the target mass of type B blast furnace cement, is weighed out using the same instrument. Therefore, it is difficult to show the breakdown of the weighed-out cement mass as reliable and objective evidence.

[0099] In this embodiment, the error between the measured mass of the weighed Portland cement and its target mass, and the error between the measured mass of the weighed blast furnace cement type B and its target mass are also recorded in the storage device 33. The recorded errors allow for immediate confirmation of the quality of the manufactured type A equivalent concrete.

[0100] As described above, Portland cement is supplied from the cement weighing device 21 to the mixer 5, and at the same time, fine aggregate (for example, sand) weighed by the fine aggregate weighing device 23X is also supplied to the mixer 5. This prevents the powdered Portland cement from becoming airborne as dust.

[0101] As described above, water is not supplied to the mixer 5 when either Portland cement or blast furnace cement type B is supplied to the mixer 5. Water is then supplied to the mixer 5 from the stage onward when the other Portland cement or blast furnace cement type B is supplied to the mixer 5. Therefore, it is prevented that either Portland cement or blast furnace cement type B reacts with water before the materials are mixed together in the mixer 5 for the production of concrete equivalent to type A.

[0102] The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the technical idea of ​​the present invention. For example, any of the following modifications 1 to 3 may be adopted individually, or two or more of modifications 1 to 3 may be adopted in any combination. In this case, the points not described below are the same as described above.

[0103] (Example of change 1) Portland cement and blast furnace cement type B are measured out and supplied to the mixer 5 in the first and second stages, respectively, as described above. The measured water (and chemical admixture) may be supplied to the mixer 5 after the other cement is supplied to the mixer 5 (for example, in step S29, or after step S29 and before step S3).

[0104] On the other hand, aggregate (for example, coarse aggregate) may be weighed out at any point, and the weighed-out aggregate may be supplied to the mixer 5 in the second stage, or after the second stage but before step S3, or after step S3. If the aggregate is supplied to the mixer 5 after step S3, the aggregate may be further mixed with the materials already mixed in step S3 (Portland cement, blast furnace cement type B, water, and chemical admixture) by the mixer 5 after the supply.

[0105] (Example of change 2) The above describes the case where two types of aggregate, fine aggregate and coarse aggregate, are used. However, the types of aggregate used to produce concrete equivalent to Type A may be one type (for example, fine aggregate) or three or more types.

[0106] In this case, the timing for weighing out each of the one type of aggregate, or three or more types of aggregate, using the weighing device and supplying them to the mixer 5 may be the first stage described above, the second stage, or after step S3 described above.

[0107] Even in such cases, by supplying Portland cement from the cement weighing device 21 to the mixer 5 in the first or second stage, and simultaneously adding fine aggregate (e.g., sand) measured by the fine aggregate weighing device 23X to the mixer 5 so that they mix together, it is possible to suppress the scattering of the powdered Portland cement, as described above.

[0108] Furthermore, if only one type of aggregate is used, either the fine aggregate supply device 13X and the fine aggregate weighing device 23X, or the coarse aggregate supply device 13Y and the coarse aggregate weighing device 23Y, may be omitted. If three or more types of aggregate are used, the number of aggregate supply devices, such as the fine aggregate supply device 13X, may be the same as the number of aggregate types used, and the number of aggregate weighing devices, such as the fine aggregate weighing device 23X, may be less than or equal to the number of aggregate types used.

[0109] If the number of aggregate weighers is the same as the number of types of aggregate used, the control unit 31 treats one aggregate supply device and aggregate weigher as one set for each type, and for each set (i.e., for each type), the control unit 31 controls the weighing of the aggregate of that type and supplying it to the mixer 5 based on the target mass of the corresponding aggregate type, similar to the case of the fine aggregate supply device 13X and fine aggregate weigher 23X described above. At that time, for each type, the control unit 31 may store the measured mass value of the weighed aggregate and the error calculated by the error calculation unit 31a between the measured mass value and the target mass of that aggregate type in the storage device 33 as measurement data for that type, associated with the identification information of the A-type equivalent concrete to be manufactured.

[0110] If the number of aggregate weighers is less than the number of types of aggregate used, both aggregate weighers that cumulatively weigh multiple types of aggregate and aggregate weighers that weigh only one type of aggregate may be provided, or only aggregate weighers that cumulatively weigh multiple types of aggregate may be provided.

[0111] (Example of change 3) In the above-described embodiment, the weighing device 3 (control unit 31) may be configured to record at least the first and fourth weighing values ​​(the measured mass values ​​of one and the other of the weighed Portland cement and blast furnace cement type B) as quality data in the storage device 33, in association with the identification information input in step S1.

[0112] In this case, in one example, the weighing device 3 (control unit 31) may record the first and fourth weighing values, along with the first and fourth errors, or the first and second target masses, as quality data in the storage device 33, in association with the aforementioned identification information. In another example, the weighing device 3 (control unit 31) may record the first and fourth weighing values, along with the first and fourth errors and the first and second target masses, as quality data in the storage device 33, in association with the aforementioned identification information.

[0113] In another example, the weighing device 3 does not need to record the first to sixth errors in the storage device 33 in steps S23 and S28. In this case, the error calculation unit 31a does not need to be provided. [Explanation of symbols]

[0114] 3 Measuring device, 5 Mixer, 10 Concrete manufacturing device, 11 First supply device, 11a Storage bottle, 11b Opening / closing gate, 12 Second supply device, 12a Storage bottle, 12b Opening / closing gate, 13X Fine aggregate supply device (aggregate supply device), 13Y Coarse aggregate supply device (aggregate supply device), 13a Storage bottle, 13b Opening / closing gate, 14 Admixture supply device, 14a Storage bottle, 14b Valve, 15 Water supply device, 15a Storage bottle, 15b Valve, 21 Cement measuring device, 21a Measuring bottle, 21b Load cell, 21c Opening / closing gate, 22 Second measuring device, 22a Measuring bottle, 22b Load cell, 22c Opening / closing gate, 23X Fine aggregate weighing device (aggregate weighing device), 23Y Coarse aggregate weighing device (aggregate weighing device), 23a Measuring bottle, 23b Load cell, 23c Opening / closing gate, 24 Liquid weighing device, 24a Measuring bottle, 24b Load cell, 24c Valve, 31 Control unit, 31a Error calculation unit, 33 Memory device

Claims

1. A weighing method for producing concrete equivalent to blast furnace cement type A by mixing Portland cement in which the mass percentage of blast furnace slag is 0% to 5% but it is difficult to determine which value is within that range, Blast furnace cement type B in which the mass percentage of blast furnace slag is 40% to 45% but it is difficult to determine which value is within that range, fine aggregate, coarse aggregate, water, and chemical admixture in a mixer. (A1) Either the Portland cement or the blast furnace cement type B is weighed using a cement weighing device based on the mass measurement value of the one and the first target mass, and the weighed one is supplied to the mixer. (A2) After supplying the one measured in (A1) from the cement weigher to the mixer, the other of the Portland cement and blast furnace cement type B is measured using the same cement weigher based on the mass measurement value of the other and the second target mass, and the measured other is supplied to the mixer. (A3) Based on the measured mass of the fine aggregate and the target mass of the fine aggregate, the fine aggregate is weighed using a fine aggregate weighing device, and the weighed fine aggregate is supplied to the mixer. (A4) Based on the measured mass of the coarse aggregate and the target mass of the coarse aggregate, the coarse aggregate is weighed using a coarse aggregate weighing device, and the weighed coarse aggregate is supplied to the mixer. (A5) Based on the mass measurement value of the chemical admixture and the target mass of the admixture, the chemical admixture is weighed out using a liquid measuring device, and then, based on the mass measurement value of the liquid obtained by combining the chemical admixture and the water and the target mass of the water, the liquid is weighed out using the liquid measuring device, and the weighed-out liquid is supplied to the mixer. (B1) The error calculation unit calculates the first to sixth errors, respectively, the error between the measured mass value of one of the measured materials and the first target mass, the error between the measured mass value of the measured fine aggregate and the target mass of the fine aggregate, the error between the measured mass value of the measured coarse aggregate and the target mass of the coarse aggregate, the error between the measured mass value of the other of the measured materials and the second target mass, the error between the measured mass value of the measured chemical admixture and the target mass of the admixture, and the error between the measured mass value of the liquid, which is a mixture of the measured chemical admixture and the water, and the target mass of the water. (B2) Check whether the errors in the first to sixth items are within their respective allowable ranges. (C) The measured Portland cement, blast furnace cement type B, fine aggregate, coarse aggregate, chemical admixture, and water are mixed in the mixer to produce concrete equivalent to blast furnace cement type A. (D) Quality data for showing the quality of the concrete to a third party, wherein the error calculation unit records the quality data used for verifying the quality in a storage device. The quality data is data obtained by associating the measured mass values ​​of the one component, the other component, the fine aggregate, the coarse aggregate, the chemical admixture, and the liquid (a mixture of the chemical admixture and water) with the first to sixth errors, using the error calculation unit to match them with the concrete identification information. A weighing method for manufacturing concrete equivalent to blast furnace cement type A, and then showing the quality of the concrete to a third party using the quality data.

2. The weighing method according to claim 1, wherein the Portland cement is supplied from the cement weighing device to the mixer, and at the same time, the fine aggregate weighed by the fine aggregate weighing device is supplied to the mixer.

3. The weighing method according to claim 1 or 2, wherein the measured water and chemical admixture are supplied to the mixer when (A2) is performed, or after (A2) and before (C).

4. The weighing method according to any one of claims 1 to 3, wherein if at least one of the errors in (B2) is outside the permissible range, (C) is discontinued.

Images