Quality evaluation device and quality evaluation method

Abstract

To provide a quality evaluation device and a quality evaluation method that can enhance the accuracy of determining the quality of ready mixed concrete.SOLUTION: According to an embodiment, a quality evaluation device is a quality evaluation device 1 for ready mixed concrete that flows down along an inclined surface of a chute. The quality evaluation device 1 includes a camera 2 for capturing images of the chute and the ready mixed concrete, and a chute shape determination unit 11 for determining a three-dimensional shape of the chute from an image captured by the camera 2, and a concrete property identification unit 12 for identifying the ready mixed concrete flowing down from the image captured by the camera 2. The concrete property identification unit 12 includes a height calculation unit 13 for calculating the height of the ready mixed concrete relative to an intersection point between the ready mixed concrete and the chute in a plane orthogonal to the direction in which the ready mixed concrete flows down. The quality evaluation device 1 includes a quality determination unit 16 for determining the quality of the ready mixed concrete on the basis of the property of the ready mixed concrete calculated by the concrete property identification unit 12.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a quality evaluation device and a quality evaluation method for ready-mixed concrete. [Background technology]

[0002] Patent Document 1 describes a quality evaluation device that inspects ready-mixed concrete transported by an agitator vehicle before it is poured into a pump vehicle. The quality evaluation device includes a camera that takes video of the ready-mixed concrete, a surface recognition unit that recognizes the surface of the ready-mixed concrete, a slope calculation unit that calculates the slope of the surface of the ready-mixed concrete, and a quality determination unit that determines the quality of the ready-mixed concrete from the calculated slope.

[0003] In this quality evaluation device, a camera captures video of ready-mixed concrete flowing down an inclined surface. A surface recognition unit recognizes the surface of the ready-mixed concrete from the captured video, and a slope calculation unit calculates the slope of the surface shape of the ready-mixed concrete from the recognized surface of the ready-mixed concrete. A quality determination unit determines the quality of the ready-mixed concrete from the slope of the surface shape of the ready-mixed concrete.

[0004] Ready-mixed concrete with a low slump value and hardness flows thicker than softer ready-mixed concrete, so the above-mentioned slope fluctuates more. The quality assessment unit assesses the quality of the ready-mixed concrete from the above-mentioned slope of the ready-mixed concrete, thereby eliminating ready-mixed concrete with a low slump value and hardness. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7122276 Summary of the Invention [Problem to be solved by the invention]

[0006] The quality evaluation device described above determines the quality of fresh concrete from the slope, thereby eliminating hard fresh concrete with a low slump value. However, soft fresh concrete with a high slump value is less likely to exhibit the above slope when flowing down the chute. Therefore, it may be impossible to accurately determine the quality of soft fresh concrete with a high slump value. Therefore, it is necessary to accurately determine whether fresh concrete is too hard or too soft, thereby improving the accuracy of quality determination.

[0007] An object of the present disclosure is to provide a quality evaluation device and a quality evaluation method that can improve the accuracy of determining the quality of ready-mixed concrete. [Means for solving the problem]

[0008] (1) A quality evaluation device according to the present disclosure is a quality evaluation device for fresh concrete flowing down the inclined surface of a chute. The quality evaluation device includes a camera that photographs the chute and the fresh concrete, a chute shape identification unit that identifies the three-dimensional shape of the chute from the image photographed by the camera, and a concrete property identification unit that identifies the fresh concrete flowing down from the image photographed by the camera. The concrete property identification unit has a height calculation unit that calculates the height of the fresh concrete relative to the intersection of the fresh concrete and the chute on a plane perpendicular to the direction in which the fresh concrete flows down. The quality evaluation device includes a quality determination unit that determines the quality of the fresh concrete based on the properties of the fresh concrete calculated by the concrete property identification unit.

[0009] In this quality evaluation device, a camera photographs the chute and fresh concrete, and a chute shape identification unit identifies the three-dimensional shape of the chute. The height of fresh concrete flowing down the chute correlates with the hardness of the fresh concrete. That is, the harder the fresh concrete, the higher the height of the fresh concrete, and the softer the fresh concrete, the lower the height of the fresh concrete. In this quality evaluation device, a height calculation unit calculates the height of the fresh concrete relative to the intersection of the fresh concrete and the chute on a plane perpendicular to the direction in which the fresh concrete flows down, and the quality of the fresh concrete is determined from this height. Therefore, fresh concrete with a low height can be determined to be too soft, and fresh concrete with a high height can be determined to be too hard. Therefore, fresh concrete that is too hard and fresh concrete that is too soft can be accurately determined, thereby improving the accuracy of determining the quality of fresh concrete.

[0010] (2) In the above (1), the concrete property identification unit may further include a flow rate calculation unit that calculates the flow rate of the fresh concrete flowing down. In this case, the quality of the fresh concrete is determined from the flow rate and height of the fresh concrete flowing down. Therefore, since the quality can be determined according to the flow rate of the fresh concrete, the quality can be determined with higher accuracy.

[0011] (3) In the above (1) or (2), the concrete property identification unit may further include a flow velocity calculation unit that calculates the flow velocity of the fresh concrete flowing down. In this case, the quality of the fresh concrete is determined from the flow velocity and height of the fresh concrete flowing down. Therefore, the quality can be determined according to the flow velocity of the fresh concrete, and therefore the quality can be determined with higher accuracy.

[0012] (4) In any of (1) to (3) above, the chute may have a rectangular shape in plan view. The chute shape identification unit may identify the three-dimensional shape of the chute by detecting at least three of the four corners of the chute in plan view. In this case, the three-dimensional shape of the chute can be identified with high accuracy, further improving the accuracy of determining the quality of ready-mixed concrete.

[0013] (5) A quality evaluation method according to the present disclosure is a quality evaluation method for fresh concrete flowing down the inclined surface of a chute. The quality evaluation method includes the steps of: flowing the fresh concrete down the inclined surface; photographing the chute and the fresh concrete; identifying the three-dimensional shape of the chute from the image obtained in the photographing step; identifying the fresh concrete flowing down from the image; calculating the height of the fresh concrete relative to the intersection of the fresh concrete and the chute on a plane perpendicular to the direction in which the fresh concrete flows down; and determining the quality of the fresh concrete from the height.

[0014] In this quality evaluation method, the chute and fresh concrete are photographed, and the three-dimensional shape of the chute is identified. Then, as with the quality evaluation device described above, the height of the fresh concrete relative to the intersection of the fresh concrete and the chute on a plane perpendicular to the direction in which the fresh concrete flows is calculated, and the quality of the fresh concrete is determined from this height. Therefore, fresh concrete with a low height can be determined to be too soft, and fresh concrete with a high height can be determined to be too hard. Therefore, this quality evaluation method can achieve the same effects as the quality evaluation device described above. [Effects of the Invention]

[0015] According to the present disclosure, the accuracy of determining the quality of ready-mixed concrete can be improved. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram showing an example of a quality evaluation site equipped with a quality evaluation device according to an embodiment. [Figure 2] FIG. 2 is a side view showing a camera, an agitator vehicle, and a pump vehicle arranged at the site of FIG. [Figure 3] FIG. 3 is a block diagram illustrating an example of the functions of the quality evaluation device according to the embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a three-dimensional shape of a shot. [Figure 5]FIG. 5 is a perspective view showing ready-mixed concrete flowing down a chute. [Figure 6] FIG. 6 is a diagram schematically showing the movement direction and movement distance of points on an image of flowing fresh concrete. [Figure 7] FIG. 7 is a diagram for explaining the calculation of the height of the flowing fresh concrete. [Figure 8] FIG. 8 is a graph showing an example of the relationship between slump flow and height of fresh concrete. [Figure 9] FIG. 9 is a graph showing an example of the relationship between the height, flow rate, and flow velocity of the flowing fresh concrete and the slump flow. [Figure 10] FIG. 10 is a flowchart illustrating an example of steps of a quality evaluation method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of a ready-mixed concrete quality evaluation device and quality evaluation method according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are given the same reference numerals, and duplicate explanations will be omitted as appropriate. The drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional ratios, angles, etc. are not limited to those shown in the drawings.

[0018] With reference to Fig. 1, a construction site E will be described as an example to which the quality evaluation device 1 according to this embodiment is applied. The construction site E where the quality evaluation device 1 is installed includes, for example, a ready-mixed concrete plant R, an agitator vehicle A, a pump vehicle B, and a pouring site Q. For example, a plurality of agitator vehicles A are arranged at the construction site E, and the quality evaluation device 1 evaluates the ready-mixed concrete of each of the plurality of agitator vehicles A. At the pouring site Q, ready-mixed concrete C (see Fig. 5) is poured from a pump vehicle B.

[0019] The quality evaluation device 1 performs quality evaluation of the ready-mixed concrete C, for example, before the ready-mixed concrete C is poured at a pouring site Q. For example, the quality evaluation device 1 rejects hard ready-mixed concrete C and soft ready-mixed concrete C. The quality evaluation device 1 may also evaluate the ready-mixed concrete C at a ready-mixed concrete plant R having a loading hopper R1. The quality evaluation device 1 may also manage the transportation of the ready-mixed concrete C using an agitator vehicle A.

[0020] As shown in Figures 1 and 2, the agitator vehicle A is a vehicle that transports ready-mixed concrete C produced at a ready-mixed concrete plant R to a construction site E. The agitator vehicle A has a cylindrical drum A1 that contains the ready-mixed concrete C. The drum A1 agitates the ready-mixed concrete C by rotating while containing the ready-mixed concrete C.

[0021] Pump vehicle B is a vehicle that pours ready-mixed concrete C transported by agitator vehicle A into a formwork installed at a casting site Q. A chute 3, which is a transport path for the ready-mixed concrete C, is provided at the rear of the agitator vehicle A. A quality evaluation device 1 evaluates the quality of the ready-mixed concrete C flowing along the inclined surface of the chute 3.

[0022] The quality evaluation device 1 evaluates the quality of ready-mixed concrete C being transported, for example, from a ready-mixed concrete plant R to a pump truck B. The quality evaluation device 1 includes a chute 3 and a camera 2 that photographs the ready-mixed concrete C. The quality evaluation device 1 evaluates the quality of the ready-mixed concrete C from an image (e.g., a video) of the ready-mixed concrete C photographed by the camera 2. As an example, the frame rate of the video photographed by the camera 2 is 30 fps.

[0023] The quality evaluation device 1 judges, for example, whether the quality of ready-mixed concrete C is acceptable. Ready-mixed concrete C that has been judged acceptable by the quality evaluation device 1 is, for example, continuously transported to a pump truck B via a chute 3, and then cast at a casting site Q. On the other hand, ready-mixed concrete C that has been judged unacceptable by the quality evaluation device 1 is, for example, rejected before arriving at the casting site Q.

[0024] The quality evaluation device 1 may evaluate the quality of the ready-mixed concrete C transported by the agitator vehicle A before the ready-mixed concrete C is poured into the pump vehicle B. In this case, it is possible to eliminate poor-quality ready-mixed concrete C before the ready-mixed concrete C is poured into the pump vehicle B. The ready-mixed concrete C is fresh concrete and is unloaded in an unhardened state. If a problem occurs with the ready-mixed concrete C after it has hardened, it will require a great deal of time and cost to repair or remove it, so it is important to perform a sufficient quality inspection before it hardens. The quality evaluation device 1 evaluates the quality of the ready-mixed concrete C transported to the construction site E by the agitator vehicle A, and, for example, inspects whether the hardness of the ready-mixed concrete C is appropriate, specifically, whether the slump or slump flow of the ready-mixed concrete C is within a certain range.

[0025] Camera 2 is disposed, for example, outside agitator vehicle A. As an example, camera 2 is disposed next to pump vehicle B. For example, camera 2 is disposed diagonally above chute 3, and photographs chute 3 and ready-mixed concrete C flowing through chute 3 from diagonally above. In other words, the angle of view of camera 2 is diagonally above chute 3 (other than directly above and directly in front).

[0026] The camera 2 photographs the chute 3 and the ready-mixed concrete C from diagonally above, allowing for a clearer image of the boundary between the ready-mixed concrete C and the chute 3. An acceptance inspection of the ready-mixed concrete C is performed by the camera 2 capturing an image of the ready-mixed concrete C flowing down the chute 3. The quality evaluation device 1 performs the acceptance inspection outside the agitator car A, making it possible to inspect the ready-mixed concrete C in each of multiple agitator cars A using a single quality evaluation device 1.

[0027] Fig. 3 is a block diagram showing an example of the functions of the quality evaluation device 1. Note that the functions of the quality evaluation device 1 are not limited to those shown in Fig. 3 and can be changed as appropriate. As shown in Figs. 2 and 3, the quality evaluation device 1 has a camera 2, a determination unit 10 that determines the quality of ready-mixed concrete C from an image captured by the camera 2, and an output unit 20 that outputs the determination result made by the determination unit 10. The output unit 20 has a display unit 21 that displays the determination result made by the determination unit 10.

[0028] The camera 2 photographs the chute 3 and the ready-mixed concrete C flowing diagonally downward in the chute 3. For example, the camera 2 is placed on a tripod 2a, and photographs the ready-mixed concrete C flowing in the chute 3 from a direction that forms a certain angle (for example, 45°) above the horizontal plane. The camera 2 outputs the photographed images of the chute 3 and the ready-mixed concrete C to the determination unit 10 in real time. Note that the images of the chute 3 and the ready-mixed concrete C photographed by the camera 2 may be displayed on the display unit 21. In this case, it is also possible to visually check the properties of the ready-mixed concrete C.

[0029] The determination unit 10 receives captured images of the chute 3 and ready-mixed concrete C from the camera 2. The determination unit 10 may be provided in a computer such as a personal computer, and is capable of communicating with both the camera 2 and the output unit 20. The computer in which the determination unit 10 is provided includes, for example, a processor (e.g., a CPU) that executes an operating system and application programs, a main memory unit including ROM and RAM, etc., an auxiliary memory unit including a hard disk or flash memory, etc., and a communication control unit including a network card or a wireless communication module.

[0030] The computer functional elements of the judgment unit 10 are realized by loading software into the processor or main memory and executing that software. The processor operates the communication control unit according to the instructions of the software, and reads or writes data from or to the main memory or auxiliary memory. Data required for computer processing is stored in the main memory or auxiliary memory.

[0031] The judgment unit 10 has, as functional elements, for example, a chute shape identification unit 11 that identifies the shape of the chute 3, and a concrete property identification unit 12 that identifies the ready-mixed concrete C flowing through the chute 3. The concrete property identification unit 12 has a height calculation unit 13 that calculates the height of the ready-mixed concrete C flowing through the chute 3. The judgment unit 10 further has, as functional elements, a quality judgment unit 16 that judges the quality of the ready-mixed concrete C, and a memory unit 17 that stores information used to judge the quality of the ready-mixed concrete C.

[0032] The chute shape identification unit 11 identifies the three-dimensional shape of the chute 3 from the image captured by the camera 2. The "three-dimensional shape of the chute" refers to the overall shape and dimensions of the chute, and more specifically, refers to the shape of the chute, which is a semi-cylindrical shape with a U-shaped cross section.

[0033] FIG. 4 is a perspective view showing an example of the chute 3. As shown in FIG. 4, the chute 3 has an inclined surface 3d (upper surface) along which the fresh concrete C flows, and the inclined surface 3d is a concave curved surface. The inclined surface 3d has a U-shaped cross section perpendicular to the direction D1 along which the fresh concrete C flows, and the fresh concrete C flows down inside the U-shaped cross section of the chute 3. The length of the chute 3 in direction D2, which is the width direction of the chute 3, gradually decreases, for example, from upstream to downstream of the flow path of the fresh concrete C in the chute 3. For example, the chute shape identification unit 11 identifies the three-dimensional shape of the chute 3 by analyzing the image of the chute 3 captured by the camera 2 using deep learning with a posture estimation method.

[0034] The chute 3 has a quadrangular shape in a planar view. That is, the chute 3 has a quadrangular portion 3c that has a quadrangular shape in a planar view. The quadrangular portion 3c has, for example, a trapezoidal shape. The chute shape identification unit 11 detects at least three of the four corners 3b of the chute 3 in a planar view to identify the three-dimensional shape of the chute 3.

[0035] For example, the chute shape identification unit 11 may detect the four corners 3b (quadrature portions 3c) of the chute 3 in a planar view to identify the three-dimensional shape of the chute 3. In this case, the shape of the chute 3 can be identified more easily and accurately than when only three of the four corners 3b are detected.

[0036] The memory unit 17 stores, for example, the three-dimensional shape of a chute in advance. For example, the shape of a chute for pouring ready-mixed concrete is standardized in advance, and the memory unit 17 stores the three-dimensional shapes of multiple types of standardized chutes. For a standardized chute, the three-dimensional shape of the chute can be determined by knowing the shape of the aforementioned rectangular portion 3c. The chute shape identification unit 11 extracts, for example, information about a chute having the same shape as the rectangular portion 3c photographed by the camera 2 from the memory unit 17, and identifies the extracted three-dimensional shape of the chute as the three-dimensional shape of the chute 3. In this way, the three-dimensional shape of the chute 3 is identified.

[0037] 3 and 5, the concrete property identification unit 12 identifies the flowing fresh concrete C from the image captured by the camera 2. For example, the concrete property identification unit 12 has a flow rate calculation unit 14 that calculates the flow rate of the fresh concrete C flowing down the chute 3, and a flow velocity calculation unit 15 that calculates the flow velocity of the fresh concrete C flowing down the chute 3. The flow velocity calculation unit 15 recognizes the surface of the fresh concrete C from the image captured by the camera 2, for example. The flow velocity calculation unit 15 calculates the velocity of the surface of the fresh concrete C.

[0038] 5 and 6, for example, the flow velocity calculation unit 15 recognizes multiple points P1 moving in a video of ready-mixed concrete C flowing down the chute 3. The flow velocity calculation unit 15 captures, for example, the movement direction and movement distance of the multiple points P1 over a certain period of time (for example, between frames) as vectors (for example, arrow Y).

[0039] The flow velocity calculation unit 15 recognizes the multiple points P1, for example, inside a parallelogram-shaped frame F. The frame F is set, for example, at the center of the direction D1 of the chute 3. As a result, the flow velocity calculation unit 15 calculates the flow velocity of the fresh concrete C at the center of the direction D1 of the chute 3. The flow velocity calculation unit 15 recognizes the multiple points P1 moving in the video of the fresh concrete C, and calculates the flow velocity of the fresh concrete C from the movement direction and movement distance of the multiple points P1 over a certain period of time.

[0040] For example, the flow rate calculation unit 14 calculates the flow rate of the ready-mixed concrete C by detecting an intersection P2 between the chute 3 identified by the chute shape identification unit 11 and the ready-mixed concrete C. However, the flow rate calculation unit 14 may calculate the flow rate of the ready-mixed concrete C by a method other than detecting the intersection P2.

[0041] 3 and 7, the height calculation unit 13 calculates the height d of the fresh concrete C relative to an intersection P2 between the fresh concrete C and the chute 3 on a plane perpendicular to the direction D1 in which the fresh concrete C flows. The height calculation unit 13 calculates the height d relative to the intersection P2 between the end of the fresh concrete C and the chute 3 in direction D2, which is the width direction of the chute 3. For example, the height calculation unit 13 calculates the length of a line segment L1 that extends vertically upward from the lowest point 3f of the chute 3 identified by the chute shape identification unit 11 to the surface C1 of the fresh concrete C on a cross section of the chute 3 perpendicular to direction D1. The height calculation unit 13 then identifies an intersection P3 between the line segment L1 and an imaginary straight line L2 that extends horizontally from the intersection P2, and calculates the length from the intersection P3 to the surface C1 of the fresh concrete C as the height d.

[0042] The flow rate calculation unit 14 may calculate the cross-sectional area of ​​the fresh concrete C in a plane perpendicular to the direction D1 from the height d calculated by the height calculation unit 13, and calculate the flow rate of the fresh concrete C from the calculated cross-sectional area and flow velocity. The flow rate calculation unit 14 may also calculate the cross-sectional area of ​​the fresh concrete C in a plane perpendicular to the direction D1 from the intersection point P2 described above, and calculate the flow rate of the fresh concrete C from the calculated cross-sectional area and flow velocity. In this way, the method by which the flow rate calculation unit 14 calculates the flow rate of the fresh concrete C is not particularly limited.

[0043] The quality determination unit 16 determines the quality of the ready-mixed concrete C from the height d of the ready-mixed concrete C calculated by the height calculation unit 13. For example, as shown in FIG. 8, there is a correlation between the height d and the slump flow of the ready-mixed concrete C. That is, the larger the height d, the smaller the slump flow, and vice versa. The quality determination unit 16 may calculate the slump flow of the ready-mixed concrete C from the relationship between the height d and the slump flow that is stored in advance in the memory unit 17. In this case, it is possible to quickly calculate the slump flow.

[0044] However, the condition of the fresh concrete C flowing through the chute 3 may change, and when the relationship between the height d and the slump flow is used as described above, the condition of the flowing fresh concrete C is not taken into consideration, and there is room for improvement in terms of the accuracy of determining the quality of the fresh concrete C. Therefore, the quality determination unit 16 may calculate the slump flow using the height d and the flow velocity of the fresh concrete C. Alternatively, the quality determination unit 16 may calculate the slump flow using the height d and the flow rate of the fresh concrete C.

[0045] In this embodiment, the quality determination unit 16 determines the quality of the fresh concrete C from the height d, the flow velocity of the fresh concrete C, and the flow rate of the fresh concrete C. For example, the quality determination unit 16 calculates the slump flow SF (slump flow value) of the fresh concrete C from equation (1) using the height d of the fresh concrete C, the flow velocity V of the fresh concrete C, and the flow rate Q of the fresh concrete C. SF=a1×V+a2×Q+a3×d+b (1) In equation (1), a1, a2, and a3 are coefficients, and b is an intercept. Note that it is also possible to calculate slump SP (slump value) using equation (1) instead of slump flow SF.

[0046] FIG. 9 is a graph showing an example of the relationship (relationship of formula (1)) between slump flow SF, height d, flow velocity V, and flow rate Q. The values ​​of a1, a2, a3, and b in formula (1) are preset values ​​and can be determined by experiments or the like conducted before operating the quality evaluation device 1. The values ​​of a1, a2, a3, and b may be set based on the mix proportions, mix characteristics, and individual differences of the ready-mixed concrete C, which differ for each construction site E.

[0047] An example of quality determination of ready-mixed concrete by the quality determination unit 16 will be described below. In the example, the quality determination unit 16 calculates the slump flow SF for ready-mixed concrete of Examples 1 to 3 in Table 1 below. In Table 1, W / C (%) indicates the ratio of water to cement in the ready-mixed concrete, and s / a (%) indicates the ratio of fine aggregate to all aggregates in the ready-mixed concrete. Air indicates the ratio of air in the ready-mixed concrete. W indicates water, C indicates cement, S1 and S2 indicate fine aggregate, and G indicates coarse aggregate.

[0048] In the ready-mix concrete of Examples 1 to 3, water W was industrial water and supernatant water, and cement C was ordinary Portland cement (density: 3.16 g / cm) manufactured by Taiheiyo Cement Corporation. 3 ) was used as the fine aggregate S1. The surface dry density was 2.56 g / cm 3 , mountain sand with a coarse grain ratio of 2.10, and fine aggregate S2 with a surface dry density of 2.64 g / cm 3 The coarse aggregate G was limestone crushed sand with a surface dry density of 2.70 g / cm. 3 The crushed limestone sand with a volume ratio of 61.0 was used. [Table 1]

[0049] A slump flow test was performed on the ready-mixed concrete of Examples 1 to 3 to obtain the values ​​of a1, a2, a3, and b in the above-mentioned formula (1). As a result, the actual measured value of the slump flow of the ready-mixed concrete of Example 1 was 506 mm, the actual measured value of the slump flow of the ready-mixed concrete of Example 2 was 625 mm, and the actual measured value of the slump flow of the ready-mixed concrete of Example 3 was 727 mm, with a1 = 4.16, a2 = -0.128, a3 = -94.0, and b = 864.2.

[0050] The slump flow SF of the ready-mixed concrete in Examples 1 to 3 was calculated from the above values ​​of a1, a2, a3, and b and formula (1), resulting in 510 mm in Example 1, 636 mm in Example 2, and 710 mm in Example 3, and values ​​close to the actually measured values ​​were obtained in all of Examples 1 to 3. As described above, the quality determination unit 16 calculates the slump flow (or slump) of the ready-mixed concrete C using formula (1), and thus the quality of the ready-mixed concrete C can be determined with high accuracy.

[0051] As shown in Figure 3, the output unit 20 includes a display unit 21 that displays the judgment result of the ready-mixed concrete C by the quality judgment unit 16, an alarm output unit 22 that outputs an alarm when the quality judgment unit 16 judges that the quality of the ready-mixed concrete C is not good, and an equipment control unit 23 that controls equipment in accordance with the judgment result of the quality judgment unit 16.

[0052] The display unit 21 includes, for example, the display of an information terminal such as a personal computer or a laptop computer, and the display of a mobile terminal such as a mobile phone or a tablet. The display unit 21 may display, for example, an image of the flowing state of the ready-mixed concrete C including the frame F, the height d of the ready-mixed concrete C, and the determination result by the quality determination unit 16 on the above display. The display unit 21 may also display time-series data of the slump flow (or slump) calculated by the quality determination unit 16 on the above display.

[0053] The alarm output unit 22 outputs an alarm when the quality determination unit 16 determines that the quality of the ready-mixed concrete C is not good. For example, the alarm output unit 22 outputs an alarm by activating a patrol light (registered trademark), a siren, or a speaker at the work site E. The alarm output unit 22 may also output an alarm to an information terminal carried by a worker.

[0054] The equipment control unit 23 controls the operation of the equipment in accordance with the evaluation result of the ready-mixed concrete C determined by the quality determination unit 16. For example, the equipment control unit 23 is capable of communicating with the rejection mechanism 30, and rejects ready-mixed concrete C whose quality determined by the quality determination unit 16 is not good. The equipment control unit 23 may reject the ready-mixed concrete C that is not good automatically or unmanned.

[0055] Furthermore, the equipment control unit 23 may be capable of communicating with a pump that pumps the ready-mixed concrete C, and may control the operation of the pump in accordance with the evaluation result of the ready-mixed concrete C by the quality determination unit 16. As an example, the equipment control unit 23 stops the pump from pumping the ready-mixed concrete C when it is determined that the quality of the ready-mixed concrete C is not good. Note that the type of equipment controlled by the equipment control unit 23 may be the removal mechanism 30 or equipment other than the pump, and may be changed as appropriate.

[0056] Next, an example of a quality evaluation method according to this embodiment will be described with reference to the flowchart shown in Fig. 10. Fig. 10 shows an example of steps of the quality evaluation method according to this embodiment. Below, an example of evaluating the quality of ready-mixed concrete C using the above-mentioned quality evaluation device 1 will be described.

[0057] First, ready-mixed concrete C is caused to flow down the inclined surface 3d of the chute 3 (step of flowing ready-mixed concrete down). Then, the chute 3 and the flowing ready-mixed concrete C are photographed (photographing step, step S1). This photographing is performed by the camera 2. The images of the chute 3 and ready-mixed concrete C photographed by the camera 2 are output in real time to the judgment unit 10, and the images are processed by the judgment unit 10.

[0058] Then, chute shape specifying unit 11 specifies the three-dimensional shape of chute 3 from the obtained image (step of specifying the three-dimensional shape of the chute, step S2). For example, chute shape specifying unit 11 detects quadrangular portion 3c from the captured image and specifies the three-dimensional shape of chute 3 by extracting from storage unit 17 the three-dimensional shape of chute 3 that has the same shape as quadrangular portion 3c.

[0059] The photographing of the chute 3 and the identification of its three-dimensional shape may be performed in advance. That is, the photographing of the chute 3 and the identification of its three-dimensional shape may be performed before pouring the ready-mixed concrete C. In this case, the chute shape identification unit 11 can identify the three-dimensional shape of the chute 3 from the image of the chute 3 photographed by the camera 2 before pouring the ready-mixed concrete C.

[0060] Next, the concrete property identification unit 12 identifies the fresh concrete C flowing through the chute 3 (step of identifying fresh concrete). At this time, the flow velocity calculation unit 15 calculates the flow velocity V of the fresh concrete C, the flow rate calculation unit 14 calculates the flow rate Q, and the height calculation unit 13 calculates the height d of the fresh concrete C (step S3).

[0061] Specifically, the flow velocity calculation unit 15 calculates the flow velocity V on the surface of the fresh concrete C by detecting the movement direction and movement distance of multiple points P1 in the image of the fresh concrete C captured by the camera 2. The flow rate calculation unit 14 identifies an intersection P2 between the chute 3 and the fresh concrete C to calculate the cross-sectional area of ​​the fresh concrete C, and calculates the product of the calculated cross-sectional area and the flow velocity V as the flow rate Q. The height calculation unit 13 then uses a line segment L1 extending vertically upward from the lowest point 3f of the chute 3 identified by the chute shape identification unit 11 to the surface C1 of the fresh concrete C and an intersection P3 between the line segment L1 and a virtual line L2 extending from the intersection P2 in the direction D2 to calculate the height d, which is the length from the intersection P3 to the surface C1 of the fresh concrete C.

[0062] Then, the quality determining unit 16 determines the quality of the ready-mixed concrete C using the height d (a step of determining the quality of ready-mixed concrete). For example, the quality determining unit 16 measures the slump flow SF from the height d, the flow velocity V of the ready-mixed concrete C, and the flow rate Q of the ready-mixed concrete C (step S4). Then, the quality determining unit 16 determines whether the measured slump flow SF is equal to or greater than a first threshold value TH1 (step S5).

[0063] When the quality determination unit 16 determines that the measured slump flow SF is not equal to or greater than the first threshold value TH1 (NO in step S5), it determines that the ready-mixed concrete C is abnormal (step S6). For example, the alarm output unit 22 outputs an alarm that the ready-mixed concrete C is abnormal, and the equipment control unit 23 controls the removal mechanism 30 to remove the ready-mixed concrete C.

[0064] If the quality determination unit 16 determines that the measured slump flow SF is equal to or greater than the first threshold value TH1 (YES in step S5), it determines whether the slump flow SF is equal to or less than a second threshold value TH2 that is greater than the first threshold value TH1 (step S7).If the quality determination unit 16 determines that the slump flow SF is not equal to or less than the second threshold value TH2 (NO in step S7), it determines that the ready-mixed concrete C is abnormal (step S6).

[0065] When the quality determination unit 16 determines that the slump flow SF is equal to or less than the second threshold value TH2 (YES in step S7), it determines that the ready-mixed concrete C is normal (step S8). For example, the display unit 21 displays on the display of the information terminal that the quality of the ready-mixed concrete C is good. Thereafter, the ready-mixed concrete C in the agitator car A is received, and the steps of the quality evaluation method are similarly performed on the next agitator car A. After the steps of the quality evaluation method have been performed on all agitator cars A, the series of processes is completed.

[0066] Next, the effects obtained from the quality evaluation device 1 and quality evaluation method according to this embodiment will be described. In the quality evaluation device 1 and quality evaluation method according to this embodiment, the camera 2 photographs the chute 3 and the ready-mixed concrete C, and the chute shape identification unit 11 identifies the three-dimensional shape of the chute 3. The height d of the ready-mixed concrete C flowing down the chute 3 correlates with the hardness of the ready-mixed concrete C. In other words, the harder the ready-mixed concrete C, the higher the height d of the ready-mixed concrete C, and the softer the ready-mixed concrete C, the lower the height d of the ready-mixed concrete C.

[0067] In the quality evaluation device 1 and quality evaluation method according to this embodiment, the height d of the fresh concrete C relative to the intersection P2 between the fresh concrete C and the chute 3 on a plane perpendicular to the direction D1 in which the fresh concrete C flows down is calculated by the height calculation unit 13, and the quality of the fresh concrete C is determined from the height d. Therefore, fresh concrete C with a low height d can be determined to be too soft, and fresh concrete C with a high height d can be determined to be too hard. Therefore, fresh concrete C that is too hard and fresh concrete C that is too soft can be accurately determined, thereby improving the accuracy of determining the quality of the fresh concrete C.

[0068] As described above, the flow rate calculation unit 14 may calculate the flow rate Q of the flowing fresh concrete C, and the quality determination unit 16 may determine the quality of the fresh concrete C from the height d and the flow rate Q. In this case, the quality of the fresh concrete C is determined from the flow rate Q and the height d of the flowing fresh concrete C. Therefore, since the quality can be determined according to the flow rate Q of the fresh concrete C, the quality can be determined with higher accuracy.

[0069] As described above, the flow velocity calculation unit 15 may calculate the flow velocity V of the flowing fresh concrete C, and the quality determination unit 16 may determine the quality of the fresh concrete C from the height d and the flow velocity V. In this case, the quality of the fresh concrete C is determined from the flow velocity V and the height d of the flowing fresh concrete C. Therefore, since the quality can be determined according to the flow velocity V of the fresh concrete C, the quality can be determined with higher accuracy.

[0070] Furthermore, as described above, both the flow velocity V and the flow rate Q of the flowing fresh concrete C may be calculated, and the quality determination unit 16 may determine the quality of the fresh concrete C from the height d, the flow velocity V, and the flow rate Q. In this case, the quality can be determined according to the flow velocity V and the flow rate Q of the fresh concrete C, so that the quality of the fresh concrete C can be determined with even higher accuracy.

[0071] In this embodiment, the chute 3 has a rectangular shape in plan view. The chute shape specifying unit 11 may detect at least three of the four corners 3b of the chute 3 in plan view to specify the three-dimensional shape of the chute 3. In this case, the three-dimensional shape of the chute 3 can be specified with high accuracy, which further improves the accuracy of determining the quality of the ready-mixed concrete C.

[0072] The above describes embodiments of the quality evaluation device and quality evaluation method according to the present disclosure. However, the quality evaluation device and quality evaluation method according to the present disclosure are not limited to the contents of the above-described embodiments and may be modified within the scope of the gist described in the claims. In other words, the configuration, shape, size, material, number, and arrangement of each part of the quality evaluation device, as well as the content and order of the steps of the quality evaluation method, may be modified as appropriate within the scope of the above-described gist.

[0073] For example, in the above-described quality evaluation device 1, an example has been described in which the quality determination unit 16 calculates the slump flow SF of the fresh concrete C from the height d, the flow rate Q, and the flow velocity V. However, the quality determination unit may calculate an index value of the fresh concrete C other than the slump flow SF. For example, the quality determination unit may calculate the V-funnel flow time of the fresh concrete C from the height d, the flow rate Q, and the flow velocity V. The V-funnel flow time is an index that indicates the viscosity of the fresh concrete C. An example in which the quality determination unit calculates the V-funnel flow time will be described below.

[0074] In the following, the quality evaluation unit estimates the rheological properties of the fresh concrete, including the viscosity and yield value, by inverse analysis. In this case, the quality evaluation device and quality evaluation method according to the present disclosure can evaluate the material separation resistance of medium-fluidity and high-fluidity fresh concrete. First, the yield value τ is calculated from the following equation (2) using the calculated slump flow SF: f Calculate (Pa).

number

[0075] Furthermore, the cross-sectional area A of the fresh concrete in the chute (for example, the area of ​​fresh concrete C in Figure 7) is divided by the wetted perimeter S, which is the length of the curved portion of the chute where the fresh concrete is located in the cross section, to calculate the diameter and depth R (cross-sectional area A / wetted perimeter S).Then, the wall shear stress τ0 (Pa) is calculated using the diameter and depth R according to the following equation (3).

number

[0076] Next, the yield value τ f , diameter depth R, and wall shear stress τ0 are used to calculate the plastic viscosity ηpl (Pa·s) of fresh concrete using the following equation (4).

number

[0077] The V-funnel flow time of each of the fresh concretes in Examples 1 to 3 was measured in advance according to JSCE-F 512. The plastic viscosity ηpl and the yield value τ f Using this, the V-funnel flow time (seconds) can be calculated using the following equation (5). V funnel flow down time = α×ηpl+β×τ f +γ (5) The measured V-funnel flow time for the ready-mixed concrete of Example 1 was 25 seconds, the measured V-funnel flow time for the ready-mixed concrete of Example 2 was 10 seconds, and the measured V-funnel flow time for the ready-mixed concrete of Example 3 was 5 seconds. Calculating α, β, and γ in equation (5) from these measured values ​​gave α = -0.012, β = 0.26, and γ = 1.0. Therefore, the V-funnel flow time can be calculated from the following equation (6). V funnel flow time=-0.012×ηpl+0.26×τ f +1.0 (6)

[0078] From the above, the quality judgment unit uses the slump flow SF calculated from the image of fresh concrete to determine the plastic viscosity ηpl and the yield value τ f , and the plastic viscosity ηpl and yield value τ f The V-funnel flow time, which is an index of viscosity, can be calculated from the above. In this way, the quality evaluation device and quality evaluation method according to the present disclosure can calculate not only the slump flow SF but also various other properties of fresh concrete by using the height d. [Explanation of symbols]

[0079] 1...quality evaluation device, 2...camera, 2a...tripod, 3...chute, 3b...four corners, 3c...rectangular section, 3d...inclined surface, 3f...lowest point, 10...judgment section, 11...chute shape identification section, 12...concrete property identification section, 13...height calculation section, 14...flow rate calculation section, 15...flow velocity calculation section, 16...quality judgment section, 17...memory section, 20...output section, 21...display section, 22...alarm output section, 23...equipment control section, 30...exclusion mechanism, A...agitator vehicle, A1...drum, B...pump vehicle, C...cement, C1...surface, D1, D2...direction, E...site, F...frame, L1...line segment, L2...virtual line, P1...point, P2, P3...intersection, Q...pouring site, R...ready-mixed concrete plant, R1...loading hopper.

Claims

1. A quality evaluation device for fresh concrete flowing down along an inclined surface of a chute, a camera for photographing the chute and the ready-mixed concrete; a chute shape determination unit that determines a three-dimensional shape of the chute from the image captured by the camera; a concrete property identification unit that identifies the fresh concrete flowing down from the image captured by the camera; Equipped with The concrete property specifying unit is A height calculation unit is provided to calculate the height of the fresh concrete relative to the intersection of the fresh concrete and the chute on a plane perpendicular to the direction in which the fresh concrete flows down, A quality determination unit is provided that determines the quality of the ready-mixed concrete based on the properties of the ready-mixed concrete calculated by the concrete property specification unit. Quality assessment equipment.

2. The concrete property identification unit further includes a flow rate calculation unit that calculates the flow rate of the fresh concrete flowing down. The quality evaluation device according to claim 1 .

3. The concrete property identification unit further includes a flow velocity calculation unit that calculates the flow velocity of the fresh concrete flowing down. The quality evaluation device according to claim 1 or 2.

4. In plan view, the chute has a rectangular shape, the chute shape specifying unit detects at least three of four corners of the chute in a plan view to specify a three-dimensional shape of the chute; The quality evaluation device according to claim 1 or 2.

5. A method for evaluating the quality of ready-mixed concrete flowing down an inclined surface of a chute, comprising: A step of flowing ready-mixed concrete down along the inclined surface; A step of photographing the chute and the ready-mixed concrete; a step of identifying a three-dimensional shape of the chute from the image obtained in the photographing step; Identifying the fresh concrete flowing down from the image; Calculating the height of the fresh concrete relative to an intersection of the fresh concrete and the chute on a plane perpendicular to the direction in which the fresh concrete flows; A step of determining the quality of the ready-mixed concrete from the height; Equipped with Quality assessment methods.

Images