JP7431182B2 - Concrete property confirmation method and concrete property identification device - Google Patents

Description

The present invention relates to a concrete property confirmation method and a concrete property identification device.

Fresh concrete delivered from a concrete plant is inspected on site as part of an acceptance inspection to confirm its properties. Sampling inspections of concrete are generally carried out every 50 to 150 ^m3 , as it takes time and effort to conduct them on all quantities. However, even if concrete is confirmed to have predetermined properties through an acceptance inspection, it may no longer meet the required performance due to changes over time. Additionally, there were concerns that concrete that did not meet the required performance would be mixed in with concrete that had not been inspected.
Therefore, when receiving fresh concrete, a person in charge may confirm that the fresh concrete satisfies the required performance by observing the fresh concrete flowing down the chute of the agitator truck. However, in visual observation, there may be differences depending on the experience and skill of the observer.
Therefore, Patent Document 1 describes a test method that makes it possible to quantitatively determine the properties of the total quantity of fresh concrete delivered. A method for calculating the slope of the surface shape of fresh concrete and determining the quality of fresh concrete from this slope is disclosed. This method is based on the fact that fresh concrete with low slump and hardness tends to have a large slope due to its height at the beginning of the chute flow, whereas fresh concrete with high slump and softness tends to have a small slope. This method predicts the slump of concrete.
When receiving concrete from an agitator truck, it is common to change the opening degree of the drum gate of the agitator truck depending on the pace of concrete placement. On the other hand, the concrete slump prediction method disclosed in Patent Document 1 is an evaluation method when the opening degree of the drum gate of the agitator truck is kept constant, so construction work in which the opening degree of the drum gate is changed according to the concrete pouring pace is performed. could not be evaluated appropriately.

Japanese Patent Application Publication No. 2020-142398

The present invention proposes a concrete property confirmation method and a concrete property identification device that can efficiently perform a 100% inspection even on fresh concrete brought in from a plant and whose pouring amount changes depending on the construction situation. The task is to

The concrete property confirmation method of the present invention to solve the above-mentioned problems includes a criterion creation step for creating an evaluation criterion for evaluating the properties of concrete flowing down a chute, and a step of creating an evaluation criterion for evaluating the properties of concrete flowing down a chute. a photographing step of photographing, a calculation step of calculating the flow rate and speed ratio of the concrete for pouring from the photographed video of the concrete for pouring, and a step of comparing the flow rate and the speed ratio with the evaluation criteria for the pouring of the concrete. The method includes a property identification process for identifying slump or slump flow of concrete for construction. In the judgment standard creation process, the judgment flow rate is calculated from the flow width and average flow velocity of the test concrete when the test concrete with a known slump or slump flow is allowed to flow down a test chute inclined at a predetermined angle. and a determination speed for calculating a determination speed ratio which is the ratio of the flow velocity at the center in the width direction and the flow velocity at the side parts in the width direction of the test concrete flowing down the test chute. A ratio creation work and a correlation data creation work of creating correlation data of the slump or slump flow of the test concrete, the judgment flow rate, and the judgment speed ratio are performed. In the calculation step, the flow rate of the pouring concrete is calculated from the flow width and average flow velocity of the pouring concrete flowing down the chute, and the flow rate of the pouring concrete at the widthwise center of the chute is calculated. and the side flow velocity is calculated. Further, in the property identifying step, the flow rate and the speed ratio are applied to the correlation data to identify the slump or slump flow of the concrete for pouring.

According to this concrete property confirmation method, the properties of concrete (slump or slump flow) are determined based on a photographed video of concrete flowing through a chute (including at least two still images taken at a predetermined time interval). In order to confirm this, it is possible to carry out a 100% inspection, and as a result, the risk of containing concrete that does not meet the required performance can be reduced. In addition, since the properties of the concrete flowing through the chute are confirmed using the width of the concrete and the flow velocity measured at multiple locations, it is possible to make judgments according to changes in the concrete flow rate, and it is possible to make judgments according to the construction situation. Even if the implantation amount changes, 100% inspection can be performed efficiently. Furthermore, since the properties of the concrete are confirmed by applying the measured data to correlation data created in advance, it is possible to quantitatively confirm the properties.

Further, the concrete property identification device of the present invention for carrying out the concrete property confirmation method includes a photographing means for photographing the pouring concrete flowing down a chute, and a photographing means for photographing the concrete for pouring from the photographed image of the photographing means. calculation means for calculating the flow rate and flow velocity of the concrete for pouring, as well as the velocity ratio of the flow velocity at the center part in the width direction of the chute for pouring and the flow velocity at the side parts, and a test in which slump or slump flow is known. The flow rate when the test concrete flows down the chute, the judgment speed ratio which is the ratio of the flow velocity at the center in the width direction and the flow velocity at the side parts in the width direction of the test concrete, and the slump or the slump flow. The flow rate and the speed ratio calculated by the calculation means are compared with the correlation stored in the storage means, and the correlation data of the concrete for pouring is calculated. and property specifying means for specifying slump or slump flow.

In addition, in the judgment criterion creation process, the test concrete was made to flow down the chute by changing the opening degree of the drum gate of the agitator truck while keeping the inclination angle of the chute of the agitator truck constant, and the concrete was made to flow down the chute for each opening degree of the drum gate. The correlation data is created for each opening degree of the drum gate using the calculated flow rate for determination and the speed ratio for determination, and the correlation data is created for each opening degree of the drum gate, and the correlation data is calculated for the agitator track when the concrete for pouring is made to flow down in the property identification step. The slump or slump flow of the concrete for pouring may be specified by applying the flow rate and the speed ratio to the correlation data corresponding to the opening degree of the drum gate.
In addition, in the judgment criterion creation process, the test concrete was made to flow down the chute by changing the inclination angle of the chute of the agitator truck while keeping the opening degree of the drum gate of the agitator truck constant, and for each inclination angle of the chute. The correlation data is created for each inclination angle of the chute using the calculated flow rate for determination and the speed ratio for determination, and the correlation data is created for each inclination angle of the chute , and the correlation data is calculated for the agitator track when the concrete for pouring is made to flow down in the property identification step. The slump or slump flow of the concrete for pouring may be specified by applying the flow rate and the speed ratio to the correlation data corresponding to the inclination angle of the chute.
In this way, by adding the opening degree of the drum gate and the inclination angle of the chute to the criteria for determining the properties of concrete, more accurate determination becomes possible.

According to the concrete property confirmation method and concrete property identification device of the present invention, it is possible to efficiently perform a 100% inspection on fresh concrete whose placement amount changes depending on the construction situation.

It is a block diagram showing an outline of a concrete property identification device of this embodiment. It is a figure which shows concrete flowing down a chute, Comprising: (a) is a top view, (b) is a sectional view. It is a flowchart which shows the concrete property confirmation method of this embodiment. It is a flowchart which shows each work of a judgment standard creation process. It is a graph showing an example of the relationship between the flow velocity of concrete flowing down a chute and slump or slump flow. (a) is a photograph showing the condition of concrete flowing down the chute evaluated by slump flow, and (b) is a photograph showing the condition of concrete flowing down the chute evaluated by slump flow. FIG. 2 is an explanatory diagram of the Buckingham-Reiner equation, in which (a) is a cross-sectional view of a tube through which a sample flows, (b) is a plane cross-sectional view of a tube through which a sample flows, and (c) is a graph showing the relationship between flow velocity and position. It is. It is an explanatory diagram showing the relationship between the position in the chute width direction and the flow velocity of the flow in the pipe accompanied by slip in the chute, in which (a) is concrete evaluated by slump, (b) is concrete evaluated by slump flow, ( c) is concrete with a large flow rate, and (d) is concrete with a small flow rate. It is a graph showing the relationship between slump or slump flow and flow velocity, in which (a) the flow rate is 30 m ³ /h, and (b) the flow rate is 60 m ³ /h.

In this embodiment, a concrete property confirmation method will be described in which a 100% inspection is performed on fresh concrete (concrete for pouring) brought in from a concrete plant to confirm that it satisfies required performance. Concrete placement is carried out by various methods depending on the construction, such as pumping, hopper placement, etc., but fresh concrete (concrete for pouring) transported from the concrete plant using an agitator truck is transported from the drum of the agitator truck. It is discharged through a chute. Therefore, by checking the properties of fresh concrete (slump, slump flow, etc.) as it flows through the chute of the agitator truck, it is possible to conduct a 100% inspection of fresh concrete regardless of the construction method. More specifically, the concrete property confirmation method of this embodiment involves photographing fresh concrete flowing down the chute of an agitator truck when concrete is being carried in, and determining the slump, slump flow, or 500 mm flow of fresh concrete from this photographed video (image). By specifying the time, it is confirmed that the fresh concrete delivered meets the required performance.

Here, the agitator truck is equipped with a vehicle that is driven by an engine and a drum that is rotatably mounted on the vehicle and can store concrete.By rotating the drum, the concrete in the drum is stirred, and the concrete is It is configured to suppress the progress of deterioration. A drum gate is provided at the concrete discharge port of the drum to open and close the discharge port. Further, a chute having a U-shape in cross section is provided at the rear of the drum to guide the concrete discharged from the discharge port. When discharging concrete from the drum, the amount of concrete discharged is adjusted by the opening degree of the drum gate, and the chute is allowed to flow down.

In the concrete property confirmation method of this embodiment, a concrete property identification device 1 is used. FIG. 1 shows a concrete property identification device 1. As shown in FIG. 1, the concrete property identification device 1 of this embodiment includes a photographing means 2, a communication means 3, a storage means 4, a calculation means 5, a property identification means 6, a determination means 7, an output means 8.
The photographing means 2 is a camera that photographs the concrete flowing down the chute of the agitator truck. In this embodiment, a video is shot. The moving image photographed by the photographing means 2 is transmitted to the storage means 4 and the output means 8 via the communication means 3. The photographing means 2 may be fixed to the agitator track, or may be fixed to a support member or the like provided near the agitator track (for example, at a position facing the chute).

The communication means 3 transmits and receives data and signals between the means of the concrete property identification device 1 by wire or wirelessly.
The storage means 4, the calculation means 5, the property specifying means 6, and the determination means 7 are built into a so-called personal computer 10, and are connected to the photographing means 2 and the output means 8 via the communication means 3.
is connected to.

The storage means 4 stores photographic data of the photographing means 2, calculation results of the calculation means 5, identification results of the property specifying means 6, determination results of the determination means 7, and the like. Furthermore, the storage means 4 stores correlation data (correlation) between the flow rate and flow velocity when concrete with known properties (slump, slump flow, or time to reach 500 mm flow) flows down the chute, and the properties. There is. A large amount of correlation data is stored depending on the chute angle and the opening degree of the drum gate of the azimuth data track. Furthermore, the storage means 4 also stores the shape (cross-sectional dimensions, etc.) of the chute for each type of agitator truck.

Calculation means 5 calculates the flow rate and flow velocity of concrete for pouring from the moving image photographed by photographing means 2. When the calculation means 5 is activated, it reads the photographed video stored in the storage means 4 and calculates the flow rate and flow velocity of the concrete C from the photographed video. Figure 2 shows concrete C flowing down chute S. The flow rate of concrete C is calculated by estimating the flow width W of concrete C as it flows down chute S and the average flow velocity (average flow velocity) from the image, and then calculating the cross section of concrete C found from the flow width W and the shape of chute S. Calculated by multiplying the area by the average flow velocity. The flow velocity V is the time t required for a specific aggregate contained in the concrete C flowing down the chute S to flow down a predetermined distance L, or the distance L that the aggregate flows down during a predetermined time t. It is calculated by measuring the distance L and dividing the distance L by the time t (V=L/t). The flow velocity V is calculated at least at three locations of the concrete C flowing down the chute S, at the center in the width direction and at both sides. The average flow velocity is the average value of the flow velocity V measured at different positions in the width direction. The calculating means 5 also calculates the speed ratio between the flow speed at the center and the flow speed at the sides. The calculation results (flow rate, flow velocity, speed ratio) by the calculation means 5 are stored in the storage means 4.

The property specifying means 6 compares the flow rate and flow velocity calculated by the calculating means 5 with the correlation data stored in the storage means 4, and specifies the slump, slump flow, or time to reach 500 mm flow of concrete for pouring. . That is, by applying the flow rate and flow velocity (velocity ratio) of concrete C calculated by calculation means 5 to the correlation data read from storage means 4, the slump, slump flow, or time to reach 500 mm flow corresponding to the concrete is calculated. Extract.
The identification result by the property identification means 6 is stored in the storage means 4 and displayed on the output means 8.

The determining means 7 confirms that the properties of the concrete C (slump, slump flow, or time to reach 500 mm flow) are within the range of preset management reference values. The management reference value is stored in the storage means 4 as a value set in advance according to construction conditions and the like so that no problems occur during driving. If the properties of the concrete C are outside the control standard value range, an alarm is sent to the output means 8. When an alarm is issued, the alarm is displayed on the monitor of the output means 8 and an alarm sound is sounded.

The output means 8 includes a so-called monitor, a printer, and the like. The output means 8 is connected to the computer via the communication means 3. The output means 8 of this embodiment also includes a speaker that emits an alarm sound or the like. When the photographed image (moving image) photographed by the photographing means 2 is transmitted, it is displayed on the monitor of the output means 8. Further, the output means 8 outputs the calculation results calculated by the calculation means 5, the identification results by the property identification means 6, the determination results by the determination means 7, etc., on a monitor or printer (display, print, etc.).

Next, a method for confirming the properties of concrete C using the concrete property specifying device 1 will be explained. Figure 3 shows a flowchart of the method for confirming the properties of concrete C. As shown in FIG. 3, the method for confirming the properties of concrete C includes a criterion creation step S1, a photographing step S2, a calculation step S3, and a property identification step S4. The criterion creation step S1 is performed at a plant or the like, and the photographing step S2, the calculation step S3, and the property identification step S4 are performed on the concrete C brought in at the construction site.

The criterion creation step S1 is a step of creating evaluation criteria (correlation data) for evaluating the properties of the concrete C flowing down the chute S. In the judgment criteria creation step S1, the same type of agitator truck as that used to transport concrete for pouring is used in a plant that manufactures concrete C, etc., to create the evaluation criteria for concrete for pouring. Collect data. FIG. 4 shows each operation in the judgment criterion creation step S1. As shown in FIG. 4, in the determination standard creation step S1, a determination flow rate creation work S11, a determination speed ratio creation work S12, and a correlation data creation work S13 are performed.

In the determination flow rate creation work S11, the flow width of test concrete for which slump, slump flow, or 500 mm flow arrival time is known is made to flow down a chute (test chute) S inclined at a predetermined angle. W and flow velocity V are measured, and the flow width W and flow velocity V are used to calculate the flow rate F for determination. The flow width W and the flow velocity V are measured from a photographed video of the test concrete flowing down the chute S. The flow width W is the length of the concrete C flowing down the chute S in a direction perpendicular to the flow direction when viewed from above (see FIG. 2). The flow velocity is calculated by measuring the time it takes the aggregate selected from the concrete C to flow down a predetermined distance or the distance it flows down in a predetermined time, and dividing the distance by the time. The flow velocity is measured at multiple locations in the width direction of the concrete C. Calculate the average value of the flow velocity measured at multiple locations (average flow velocity). After calculating the average flow velocity, the flow rate for determination is calculated by multiplying the cross-sectional area of the concrete C calculated from the flow width W of the concrete C and the shape of the chute S by the average flow velocity.

In the determination speed ratio creation operation S12, a determination speed ratio is calculated using the flow velocity at the central portion in the width direction and the flow velocity at the side portions in the width direction of the test concrete flowing down the chute S. The speed ratio for determination is the ratio of the flow speed at the center portion in the width direction and the flow speed at the side portions in the width direction. In this embodiment, the position for measuring the flow velocity on the side in the width direction was within a range of 50 to 60 mm inside from the boundary between concrete C and chute S on the concrete surface. This is set to be within 2.5 to 3 times the maximum diameter of aggregate contained in concrete C. The calculated speed ratio for determination is stored in the storage means together with the value of slump, slump flow, or time to reach 500 mm flow.

In the correlation data creation work S13, the correlation between the slump of the test concrete, the time to reach slump flow or 500 mm flow (for example, slump 10.5 cm to 23 cm, slump flow 400 mm to 700 mm), the flow rate for determination, and the speed ratio for determination is defined. Create correlated data. The correlation data is data that is compiled by associating the judgment flow rate calculated in the judgment flow rate creation work S11 and the judgment speed ratio calculated in the judgment speed ratio creation work S12 with the value of the slump or slump flow of the test concrete. be. The correlation data is displayed on the output means 8 as a graph as necessary.
In this embodiment, correlation data is created when the opening degree of the drum gate of the agitator track (for example, in three stages, large, medium, and small) and the inclination angle of the chute S are changed. That is, correlation data for each degree of opening of the drum gate of the agitator track with the inclination angle of the chute S of the agitator track being constant, and correlation data for each degree of inclination of the chute S of the agitator track with the degree of opening of the drum gate of the agitator track being constant. Create. Further, the correlation data is created for each cross-sectional shape of the chute S of the agitator track that is expected to be used.

The photographing step S2 is a step of photographing the situation in which the concrete for pouring that has been carried into the construction site flows down the chute S. At this time, the angle of the chute S and the opening degree of the drum gate are recorded. In this embodiment, a moving image is shot. The photographed moving image is displayed on the output means 8 and is also stored in the storage means 4 together with the angle of the chute S and the opening degree of the drum gate. The angle of the chute S is measured by an inclinometer attached to the chute S. The measurement results of the inclinometer may be transmitted to the storage means 4 via the communication means 3, or may be input by the measuring person. Further, the opening degree of the drum gate may be automatically measured by installing a sensor on the drum gate in advance and transmitted to the storage means 4 via the communication means 3, or the opening degree of the drum gate may be automatically measured and transmitted to the storage means 4 via the communication means 3. You may check the opening degree of the drum gate and input it.

Calculation step S3 is a step of calculating the flow rate and speed ratio of the concrete for pouring from the photographed video of the concrete for pouring. The flow rate of the concrete for pouring is calculated from the flow width W of the concrete for pouring flowing down the chute S and the average flow velocity. Moreover, the speed ratio of the concrete for pouring is calculated from the flow velocity of the central portion in the width direction of the chute S of the concrete for pouring and the flow velocity of the side portions of the chute S of the pouring concrete.
When the photographing means 2 starts photographing concrete for pouring flowing down the chute S, the calculating means 5 is activated. The calculation means 5 calculates the flow rate and speed ratio from the moving image stored in the storage means 4. The flow rate is calculated by calculating the cross-sectional area of the pouring concrete from the measured flow width of the pouring concrete and the cross-sectional shape of the chute S, and then multiplying this by the average flow velocity of the pouring concrete flowing down the chute S. Calculated by The average flow velocity is the average value of flow velocities calculated at multiple locations (center and side) in the width direction. In this embodiment, the flow velocity is calculated at the center and side parts in the width direction of the concrete for pouring, and the average flow velocity is calculated from the average value of these values. The widthwise side portions shall be within a range of 50 to 60 mm inside from the boundary between concrete C and chute S on the concrete surface. The flow velocity is calculated by measuring the time it takes the aggregate in the pouring concrete flowing down the chute S to flow down a predetermined distance or the distance it flows down at a predetermined time, and dividing this distance by time.
Note that the calculation means 5 may be activated by operating a computer. The calculation result of the calculation means 5 is stored in the storage means 4. The flow rate and speed ratio are stored together with the angle of the chute S and the opening degree of the drum gate.

The property specifying step S4 is a step of specifying the property (slump, slump flow, or time to reach 500 mm flow) of concrete for pouring. The properties of the concrete for pouring are determined by applying the flow rate and velocity ratio to the correlation data stored in the storage means 4. At this time, correlation data corresponding to the opening degree of the drum gate of the agitator truck and the inclination angle of the chute S when pouring concrete is used.
When calculation of the flow rate and speed ratio is completed by the calculation means 5, the property identification means 6 is activated. The property specifying means 6 reads the correlation data in which the angle of the chute S and the opening degree of the drum gate match from the data stored in the storage means 4, and uses the flow rate and speed ratio calculated in the calculation step S3 as the correlation data. By applying it to the judgment flow rate and judgment speed ratio of ). The properties of the concrete for pouring specified by the property specifying means 6 are displayed on the output means 8. Further, the specified properties of the concrete for pouring are stored in the storage means along with the elapsed time from the time when it started to be discharged from the agitator truck (or from the time when it was taken out from the plant).
When the properties of the concrete for pouring are specified, the determining means 7 is activated and compares the properties of the concrete for pouring with preset management reference values. If the specified properties of the concrete for pouring are outside the range of predetermined control reference values, the output means 8 issues an alarm.

As described above, according to the method for confirming the properties of concrete C of this embodiment, in order to confirm the properties of concrete C (slump, slump flow, or time to reach 500 mm flow) based on the photographed video of concrete C flowing through chute S, all It becomes possible to carry out inspections. As a result, the risk of using concrete C that does not meet the required performance can be reduced.
Further, since the properties of the concrete C are confirmed using the width of the concrete C flowing through the chute S and the flow velocity measured at multiple locations, it is possible to make a determination according to a change in the flow rate of the concrete C. Therefore, even if the amount of implantation changes depending on the construction situation, a complete inspection can be performed efficiently.
In addition, since the properties of concrete C are specified by applying calculation results based on measurement data to correlation data created in advance, it is possible to quantitatively confirm the properties.
In addition, since the correlation data is associated with the opening degree of the drum gate and the angle of inclination of the chute S, it is possible to specify properties according to the opening degree of the drum gate and the angle of the chute S during construction, making it more accurate. Judgment becomes possible.
Since the concrete properties are automatically specified by the concrete property specifying device 1, quantitative evaluation is possible.

Here, the tendency of the flow velocity of the concrete C flowing down the chute S changes depending on the composition of the concrete C. FIG. 5 is a graph showing an example of the relationship between flow velocity and slump or slump flow. Moreover, FIG. 6 is a photograph showing the concrete C flowing through the chute S. Concrete C, which is evaluated by slump, shows a tendency for the flow rate to increase as the slump increases, as shown in FIG. 5, although there is some variation depending on the amount of water even if the formulation is the same. Furthermore, as shown in Fig. 6(a), concrete C evaluated by slump tends to flow at the same speed overall (velocity ratio between the sides and the center is approximately 1) when flowing down the chute S. (The vertical arrow in FIG. 6(a) indicates the flow velocity of concrete C). On the other hand, in concrete C evaluated by slump flow, as shown in FIG. 5, the flow rate tends to decrease as the viscosity increases. As shown in Fig. 6(b), the concrete C evaluated using slump flow with high viscosity has concrete C that is in contact with the chute S at the side of the chute S, and concrete C that is not in contact with the chute S at the center of the chute S. The flow velocity changes between concrete C (the vertical arrow in FIG. 6(b) indicates the flow velocity of concrete C). As described above, the flow rate of the concrete C flowing down the chute S may vary between the center and side portions of the chute S depending on the composition. This is because a phenomenon equivalent to the flow in the pipe accompanied by slippage (Buckingham-Reiner type) is also occurring in the concrete C flowing down the chute.

The Buckingham-Reiner equation (Equation 1) is based on the adhesive force (viscosity of sample C0) generated between the sample C0 flowing inside the tube P and the tube wall and the shear force acting on the interface between the sample C0 and the tube wall. Based on the phenomenon that there is a difference between the flow velocity of sample C0 in plug flow part C2 and the flow velocity of sample C0 in the other part (tube wall side) C1, the flow rate of sample C0 in pipe P is This is to find the relationship between the sliding speed and the sliding speed (see Fig. 7). FIG. 7 is a reference diagram of the Buckingham-Reiner equation. As shown in FIG. 7, in the plug flow section C2 (section x ₂ to x ₃ ), the flow velocity V ₂ is constant, while in the other sections (x ₁ to x ₂ and x ₃ to x ₄ ) Then, the flow velocity V ₁ decreases as it approaches the pipe wall. This is influenced by the adhesive force (viscosity of the sample) generated between the sample C0 and the tube wall and the shear force acting on the interface between the sample C0 and the tube wall. Slippage occurs when the shear force is greater than the adhesion force. As the adhesion force increases, the difference between the flow velocities V ₁ and V 2 between the plug flow portion C2 and the other portion C1 increases, and as the adhesion force decreases, the flow speed V ₁ , V ₂ between the plug flow portion C2 and the other portion C1 increases. The difference in _V2 becomes smaller.

It is assumed that the same phenomenon as in the pipe occurs also in the chute S having an arcuate (semicircular) cross section, depending on the mix of the concrete C. Here, FIG. 8 is an explanatory diagram showing an overview of the flow in the pipe accompanied by slip in the chute S, in which (a) shows concrete C evaluated by slump, (b) shows concrete C evaluated by slump flow, (c) shows the relationship between flow velocity v and position x for concrete C with a large flow rate, and (d) for concrete C with a small flow rate. Note that the concrete C flowing down the chute S has a phenomenon in which the flow velocity v varies depending on the composition of the concrete C and the flow rate of the concrete C. As shown in Fig. 8(a), the concrete C evaluated by slump has a constant flow velocity in the center due to the occurrence of plug flow part C2, and as it approaches the chute S in the side parts (moving outward). (according to) the flow velocity v is decreasing. On the other hand, in concrete C evaluated by slump flow, as shown in Fig. 8(b), since no plug flow part occurs in concrete C, a phenomenon occurs in which the flow velocity decreases as it approaches chute S from the center. . In addition, when the flow rate of concrete C is large, as shown in Fig. 8(c), a plug flow portion C2 occurs, so that the flow velocity is constant in the center and the flow rate is constant as it approaches the chute S in the side parts. Speed decreases. On the other hand, when the flow rate is small, as shown in FIG. 8(d), no plug flow portion is generated in the concrete C, so the flow rate tends to decrease as it approaches the chute S from the center.

Next, we will show the results of an experiment that confirmed the difference in the flow velocity of concrete C flowing down the chute S between the center and the sides of the chute. FIGS. 9(a) and 9(b) show the relationship between slump or slump flow and flow velocity. FIG. 9(a) shows the case where the flow rate of concrete C is set to 30 m ³ /h and FIG. 9(b) shows the case when the flow rate is set to 60 m ³ /h.
As shown in Figures 9(a) and (b), for concrete C evaluated by slump, when the slump is small, there is no difference in the flow velocity between the center and the sides, but when the slump is large (20 cm or more) ) There is a difference between the flow velocity in the center and the sides. Concrete C (medium flow concrete or high flow concrete) evaluated by slump flow tends to show a tendency that the difference between the flow velocity at the center in the width direction and the flow velocity at the sides increases as the slump flow increases. Therefore, it was confirmed that the flow velocity of the concrete C flowing down the chute S between the widthwise center and the side portions differed depending on the properties of the concrete C (slump or slump flow).

In this way, concrete C flowing down the chute S (particularly medium-flow concrete whose consistency is evaluated by slump flow or high-flow concrete whose consistency is evaluated by two parameters: slump flow and time to reach 500 mm flow) flows down chute S. There may be a difference in speed between the center part of the chute S and the side part of the chute S. On the other hand, according to the method for confirming the properties of concrete C of this embodiment, since the speed ratio of the flow velocity in the center part of the chute S and the flow velocity in the side parts is used, a more accurate Evaluation can be carried out.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and each of the above-mentioned components can be modified as appropriate without departing from the spirit of the present invention.
For example, in the embodiment described above, a case has been described in which the properties of concrete for pouring are specified at the site, but it is also possible to carry out the photographing step S2 to the property identification step S4 at the plant and correlate it with the elapsed time after concrete production. It is also possible to measure changes in concrete properties over time. By understanding changes in concrete properties over time, it is possible to reset the mix of concrete C depending on the transportation time from the plant. For example, if it is assumed that the transportation time will be longer due to traffic conditions, etc., it is possible to readjust the changes in concrete properties over time and re-set the mix so that the concrete for pouring falls within predetermined control standard values. can.
Further, in the embodiment described above, the flow rate and flow velocity of concrete C are calculated using the video taken by the photographing means, but the video used to calculate the flow rate and flow speed is It shall include at least two still images taken with a distance between them.

1 Concrete property identification device 2 Photographing means 3 Communication means 4 Storage means 5 Calculation means 6 Property identification means 7 Judgment means 8 Output means 10 Personal computer S Shoot C Concrete S1 Judgment criteria creation process S2 Photography process S3 Calculation process S4 Property identification process S11 Judgment flow rate creation work S12 Judgment speed ratio creation work S13 Correlation data creation work

Claims (4)

a criterion creation step for creating evaluation criteria for evaluating the properties of concrete flowing down the chute;
A photographing process of photographing concrete for pouring as it flows down a chute;
a calculation step of calculating the flow rate and speed ratio of the concrete for pouring from the photographed video of the concrete for pouring;
A method for confirming the properties of concrete, comprising: a property identification step of comparing the flow rate and the speed ratio with the evaluation criterion to identify slump or slump flow of the concrete for pouring,
In the judgment standard creation process, the judgment flow rate is calculated from the flow width and average flow velocity of the test concrete when the test concrete with a known slump or slump flow is allowed to flow down a test chute inclined at a predetermined angle. Creating a flow rate for judgment,
A determination speed ratio creation operation for calculating a determination speed ratio that is a ratio between the flow velocity at the center in the width direction and the flow velocity at the side portions in the width direction of the test concrete flowing down the test chute;
performing a correlation data creation work of creating correlation data that defines the correlation between the slump or slump flow of the test concrete, the judgment flow rate, and the judgment speed ratio;
In the calculation step, the flow rate of the pouring concrete is calculated from the flow width and average flow velocity of the pouring concrete flowing down the chute, and the flow rate of the pouring concrete at the widthwise center of the chute is calculated. and the side flow velocity,
A method for confirming properties of concrete, characterized in that, in the property specifying step, a slump or slump flow of the concrete for placement is specified by applying the flow rate and the speed ratio to the correlation data. a criterion creation step for creating evaluation criteria for evaluating the properties of concrete flowing down the chute;
A photographing process of photographing concrete for pouring as it flows down a chute;
a calculation step of calculating the flow rate and speed ratio of the concrete for pouring from the photographed video of the concrete for pouring;
A method for confirming the properties of concrete, comprising: a property identification step of comparing the flow rate and the speed ratio with the evaluation criterion to identify slump or slump flow of the concrete for pouring,
In the judgment criterion creation step, when test concrete with a known slump or slump flow is made to flow down the chute while keeping the inclination angle of the chute of the agitator truck constant and changing the opening degree of the drum gate of the agitator truck. creating a judgment flow rate for each opening degree of the drum gate from the flow width and average flow velocity of the test concrete;
Creating a judgment speed ratio, which is a ratio of the flow velocity at the center in the width direction and the flow velocity at the side parts in the width direction of the test concrete flowing down the chute, for each opening degree of the drum gate. work and
Correlation data defining the correlation between the slump or slump flow of the test concrete, the judgment flow rate calculated in the judgment flow rate creation work, and the judgment speed ratio calculated in the judgment speed ratio creation work is stored in the drum . Create correlation data for each gate opening ,
In the calculation step, the flow rate of the pouring concrete is calculated from the flow width and average flow velocity of the pouring concrete flowing down the chute, and the flow rate of the pouring concrete at the widthwise center of the chute is calculated. and the side flow velocity,
In the property identifying step, the flow rate and the speed ratio are applied to the correlation data corresponding to the opening degree of the drum gate of the agitator truck when the concrete for pouring is made to flow down, thereby determining the slump or slump of the concrete for pouring. A concrete property confirmation method characterized by identifying slump flow. a criterion creation step for creating evaluation criteria for evaluating the properties of concrete flowing down the chute;
A photographing process of photographing concrete for pouring as it flows down a chute;
a calculation step of calculating the flow rate and speed ratio of the concrete for pouring from the photographed video of the concrete for pouring;
A method for confirming the properties of concrete, comprising: a property identification step of comparing the flow rate and the speed ratio with the evaluation criterion to identify slump or slump flow of the concrete for pouring,
In the judgment criterion creation step, when test concrete with a known slump or slump flow is allowed to flow down the chute while keeping the opening degree of the drum gate of the agitator truck constant and changing the inclination angle of the chute of the agitator truck. creating a judgment flow rate for each inclination angle of the chute from the flow width and average flow velocity of the test concrete;
A judgment speed ratio creation operation that calculates a judgment speed ratio, which is the ratio of the flow velocity at the center in the width direction and the flow velocity at the side parts in the width direction, of the test concrete flowing down the chute, for each inclination angle of the chute. and,
Correlation data defining the correlation between the slump or slump flow of the test concrete, the judgment flow rate calculated in the judgment flow rate creation work, and the judgment speed ratio calculated in the judgment speed ratio creation work is used in the shoot Create correlation data for each inclination angle of
In the calculation step, the flow rate of the pouring concrete is calculated from the flow width and average flow velocity of the pouring concrete flowing down the chute, and the flow rate of the pouring concrete at the widthwise center of the chute is calculated. and the side flow velocity,
In the property identification step, the flow rate and the speed ratio are applied to the correlation data corresponding to the inclination angle of the chute of the azidata truck when the concrete for pouring is poured down, and the slump or slump of the concrete for pouring is determined. A concrete property confirmation method characterized by identifying slump flow. a photographing means for photographing concrete for pouring flowing down a chute;
Calculating the flow rate and flow velocity of the concrete for pouring from the photographed image of the photographing means, and calculating the speed ratio between the flow velocity of the central part in the width direction of the chute of the concrete for pouring and the flow velocity of the side parts. calculation means,
A flow rate when test concrete with a known slump or slump flow flows down a chute, and a judgment speed ratio that is the ratio of the flow velocity at the center in the width direction and the flow velocity at the side parts in the width direction of the test concrete. , a storage means in which a correlation with the slump or the slump flow is stored;
property identifying means for identifying the slump or slump flow of the concrete for pouring by comparing the flow rate and the speed ratio calculated by the calculating means with the correlation stored in the storage means; A concrete property identification device characterized by:

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