Quality control method for cement compositions

Abstract

To always grasp the flowability of a cement composition.SOLUTION: A quality management method for cement composition has a measurement step for measuring the flow condition of a cement composition flowing on an inclined part by a measurer without photographing an image, a threshold setting step for setting a threshold, and a determination step for determining the quality of the cement composition comparing the output of the measurer with the threshold, wherein the flowability condition is a flow load, the measurer is a load meter, and a load detection part includes the load meter and is inserted into the cement composition flowing on the inclined part. The load detection part outputs a signal corresponding to pressure received from the cement composition to automatically measure the flowability condition of the cement composition, and manages the flowability of the cement composition at real timing.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a method for quality control of cement compositions.

Background Art

[0002] Concrete (an example of a cement composition) decreases in fluidity over time. When the fluidity decreases, it causes defects (such as poor filling, honeycombing, and pipe blockage). Therefore, a slump (or slump flow) test is performed to evaluate the fluidity of concrete. In addition, in Patent Document 1, a recess is provided in a mixer, an image of the concrete that has entered the recess is taken when the concrete is kneaded, and the fluidity is estimated based on the taken image.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the slump test needs to be performed at specific timings (for example, at 30-minute intervals) at the site, the fluidity of concrete (cement composition) cannot be constantly grasped. Even in the method of Patent Document 1, it is difficult to constantly grasp the fluidity of concrete, and also, since this method requires modification of the drum, it cannot be generally used.

[0005] The present invention has been made in view of such problems, and an object thereof is to enable constant grasping of the fluidity of a cement composition.

Means for Solving the Problems

[0006] The main invention for achieving the above objective includes a measurement step of attaching a measuring unit to the chute of a concrete mixer truck and measuring the flow state of the cement composition flowing through the chute with a measuring meter of the measuring unit without taking an image; a threshold setting step of setting a threshold; and a determination step of determining the quality of the cement composition by comparing the output of the measuring meter with the threshold, wherein the flow state is a flow load, the measuring meter is a load cell, and the measuring unit includes the load cell. The aforementioned chute This is a quality control method for a cement composition, characterized by having a load detection unit inserted into the cement composition flowing through it, the load detection unit outputting a signal corresponding to the pressure received from the cement composition as the output of the measuring instrument, and automatically measuring the flow load of the cement composition through the measurement step, the threshold setting step and the determination step, thereby managing the fluidity of the cement composition in real time. Other features of the present invention will be made clearer by description in this specification and the accompanying drawings. [Effects of the Invention]

[0007] According to the present invention, the fluidity of the cement composition can be constantly monitored. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram illustrating an example of a concrete construction method. [Figure 2] This is a schematic diagram of the measurement unit 30 in this embodiment. [Figure 3] This is a schematic cross-sectional view showing the configuration of the probe 35. [Figure 4] Figures 4A to 4C are explanatory diagrams illustrating the method for measuring the concrete top surface height using a laser displacement meter 34. [Figure 5] Figure 5A shows the measurement data for a large slump. Figure 5B shows the measurement data for a small slump. [Figure 6]This figure shows the relationship between slump and load. [Figure 7] This diagram shows the relationship between slump and the top height of the concrete. [Figure 8] This diagram shows the relationship between slump and concrete flow velocity. [Figure 9] This diagram shows the relationship between the height of the top surface of the concrete and the load. [Figure 10] This is a flowchart illustrating the method for managing the fluidity of concrete in a comparative example. [Figure 11] This is a flowchart illustrating the method for controlling the fluidity of concrete in this embodiment. [Modes for carrying out the invention]

[0009] The following matters become clear from this specification and the accompanying drawings: The system includes a measurement step of measuring the flow state of a cement composition flowing through an inclined section with a measuring instrument without taking images, a threshold setting step of setting a threshold, and a determination step of determining the quality of the cement composition by comparing the output of the measuring instrument with the threshold, wherein the flow state is a flow load, the measuring instrument is a load cell, and includes a load detection unit inserted into the cement composition flowing through the inclined section, the load detection unit outputs a signal corresponding to the pressure received from the cement composition. This allows for the automatic measurement of the flow load of the cement composition and the real-time management of the fluidity of the cement composition. A quality control method for cement compositions characterized by [specific traits] will be revealed.

[0010] A method for controlling the quality of a cement composition is revealed, characterized by comprising: a measurement step of measuring the flow state of the cement composition flowing through an inclined section with a measuring instrument; a threshold setting step of setting a threshold; and a determination step of determining whether the cement composition is good or bad by comparing the output of the measuring instrument with the threshold.

[0011] This method of quality control for cement compositions allows for constant monitoring of the fluidity of the cement composition.

[0012] A quality control method for such a cement composition, wherein it is desirable that the threshold value is determined based on the flow state with respect to the slump of a reference cement composition.

[0013] According to such a quality control method for a cement composition, an appropriate threshold value can be set.

[0014] A quality control method for such a cement composition, wherein the flow state is a flow load, the measuring instrument is a load cell, the load cell includes a load detection unit inserted into the cement composition flowing through the inclined portion, and the load detection unit may output a signal according to the pressure received from the cement composition.

[0015] According to such a quality control method for a cement composition, the fluidity of the cement composition can be evaluated by the pressure (load) received by the load detection unit from the cement composition.

[0016] A quality control method for such a cement composition, wherein the load detection unit has a cylindrical body inserted into the cement composition and a plate member having one end fixed to the inclined portion and the other end inserted into the cylindrical body, and it is desirable that the load cell is provided between the cylindrical body and the plate member and outputs the signal according to the pressure received by the cylindrical body from the cement composition.

[0017] According to such a quality control method for a cement composition, the load received from the cement composition flowing through the inclined portion can be measured.

[0018] A quality control method for such a cement composition, wherein it is desirable that the cylindrical body is a cylinder.

[0019] According to such a quality control method for a cement composition, the flow of the cement composition becomes smooth.

[0020] A quality control method for such a cement composition, wherein the flow state is a flow height. The measuring instrument may be one that measures the height of the cement composition flowing through the inclined section.

[0021] According to this quality control method for cement compositions, the fluidity of the cement composition can be evaluated based on its height.

[0022] A method for quality control of such cement composition is provided, wherein an obstacle is inserted into the cement composition flowing through the inclined section, and the measuring instrument is preferably positioned upstream of the obstacle in the flow direction of the cement composition.

[0023] According to this quality control method for cement compositions, the cement composition tends to accumulate in front of obstacles, making it easier to evaluate its fluidity.

[0024] In a method for quality control of such cement composition, it is desirable that the measuring instrument is also positioned downstream of the obstacle in the flow direction of the cement composition.

[0025] This method of quality control for cement compositions can improve the accuracy of evaluation.

[0026] The method for quality control of such cement composition is wherein the flow state is the flow velocity, and the measuring instrument measures the velocity of the cement composition flowing through the inclined section.

[0027] According to this quality control method for cement compositions, the fluidity of the cement composition can be evaluated by its flow rate.

[0028] The method for quality control of such cement composition is preferably a non-contact Doppler type sensor.

[0029] According to this quality control method for cement compositions, the flow velocity can be easily measured.

[0030] In a method for quality control of such cement composition, it is desirable to change the threshold according to the supply speed of the cement composition during placement.

[0031] According to this quality control method for cement compositions, a threshold suitable for the supply rate can be set.

[0032] ===Execution=== <Regarding concrete construction> Figure 1 is a schematic diagram illustrating an example of a concrete construction method. In Figure 1, a ready-mix concrete truck 10 and a concrete pump truck 20 are stationed at the concrete pouring site. A ready-mix concrete truck is also called a mixer truck or agitator truck.

[0033] The ready-mix concrete truck 10 is a vehicle that transports concrete materials, which have been delivered from the concrete manufacturing plant, to the concrete pouring site while mixing them. The ready-mix concrete truck 10 is equipped with a drum 12 and a chute 14 (corresponding to an inclined section).

[0034] The drum 12 is a roughly cylindrical container for loading ready-mix concrete (hereinafter also simply referred to as concrete). The drum 12 rotates continuously while the ready-mix concrete truck 10 is in motion, mixing the concrete materials. This prevents the separation of aggregates and water, keeping the concrete homogeneous.

[0035] The chute 14 is a component for guiding (discharging) the concrete inside the drum 12 to the desired unloading position, and is provided at an inclined angle at the rear of the drum 12. In addition, the chute 14 in this embodiment is provided with a measuring section 30 (described later).

[0036] The concrete pump truck 20 is a vehicle used to pump concrete, which has been transported to the site by the ready-mix concrete truck 10, to the pouring location. The concrete pump truck 20 is equipped with a hopper 22, a pump 24, and a concrete supply pipe 26.

[0037] The hopper 22 is located at the rear of the pump truck 20 and is positioned opposite the chute 14 of the concrete mixer truck 10. The hopper 22 receives the concrete discharged from the chute 14 of the concrete mixer truck 10.

[0038] Pump 24 is, for example, a double-cylinder reciprocating pump that generates hydraulic force to push concrete supplied from hopper 22 to cylinder (not shown) out of cylinder. Pump 24 then pumps the concrete in cylinder into concrete supply pipe 26 at high pressure.

[0039] The concrete supply pipe 26 is a tubular member that delivers concrete, which is pushed out from the cylinder by the drive of the pump 24, to the pouring site (formwork, etc.).

[0040] Concrete is transferred from the chute 14 of the ready-mix concrete truck 10 to the hopper 22 of the pump truck 20, and then, driven by the pump 24, is poured through the concrete supply pipe 26 into formwork and other structures.

[0041] <Regarding the measurement unit 30> Figure 2 is a schematic diagram of the measuring unit 30 in this embodiment. Figure 3 is a schematic cross-sectional view showing the configuration of the cylindrical load cell (hereinafter referred to as probe) 35.

[0042] As shown in Figure 2, a measuring unit 30 is provided on the chute 14 of the concrete mixer truck 10. This measuring unit 30 measures the flow state of the concrete (in this embodiment, the flow state of the concrete flowing through the chute 14). In this embodiment, the measuring unit 30 is detachable from the chute 14 and can be attached to the chute 14 of the delivered concrete mixer truck 10. However, it is not limited to this, and the measuring unit 30 may be pre-attached to the chute 14 of the concrete mixer truck 10. It may also be attached to a component other than the chute 14.

[0043] As shown in Figure 2, the measuring unit 30 of this embodiment includes a pair of L-shaped angles 31 fixed to the chute 14, a steel plate 32, a magnetic stand 33, a laser displacement meter 34, and a probe 35. In Figure 2, when describing the position of each component, the side of the chute 14 where the L-shaped angles 31 are located is considered the top, and the opposite side is considered the bottom.

[0044] The L-shaped angle 31 is a steel material (angle steel) with an L-shaped cross-section. A pair of L-shaped angles 31 are positioned with the steel material 352 of the probe 35 (described later) sandwiched between them, with their outer surfaces facing each other, and are fixed in place by a vise or the like. The pair of L-shaped angles 31 are also fixed to the chute 14 by a vise or the like.

[0045] The steel plate 32 is a long, narrow flat plate fixed to the underside of a pair of L-shaped angles 31. More specifically, the steel plate 32 is positioned so that its longitudinal direction aligns with the flow direction of the concrete (corresponding to the flow direction), and its approximately central portion in the longitudinal direction is fixed to the underside of the pair of L-shaped angles 31.

[0046] The magnetic stand 33 is a component (holding device) for fixing the laser displacement meter 34 onto the iron plate 32, and is provided at both ends of the iron plate 32 in the longitudinal direction.

[0047] As shown in Figure 3, the probe 35 (corresponding to the load detection unit and obstacle) comprises a cylinder 350, a steel material 351, a steel material 352, and a load cell 353 (corresponding to the measuring instrument).

[0048] The cylinder 350 (corresponding to the cylindrical body) is a cylindrical member with a circular cross-section. However, the cross-section is not limited to a circle; it may be a cylindrical member of other shapes (e.g., triangular or square). However, using a circular cross-section (i.e., a cylinder) as in this embodiment allows for smoother concrete flow when inserted into the concrete. Furthermore, when measuring only the concrete height with the laser displacement meter 34 without using the load cell 353, any object that obstructs the concrete flow will suffice. For example, it may be a cylindrical or rectangular prism that is not cylindrical. It may also be reinforcing bars, etc.

[0049] The steel member 351 is a component for attaching the load cell 353 to the inner surface of the cylinder 350. Therefore, the surface of the steel member 351 facing the cylinder 350 is shaped to follow the shape of the inner surface of the cylinder 350 (curved), and the steel member 351 is fixed to the inner surface of the cylinder 350. Note that if the cross-section of the cylinder 350 is not circular but triangular or square, and the load cell 353 is to be attached to a straight section (flat surface), the steel member 351 may be omitted, and the load cell 353 may be attached directly.

[0050] The steel member 352 (corresponding to a plate member) is a plate-shaped member, and as shown in Figure 3, its lower end is positioned inside the cylinder 350, while its upper end extends above the cylinder 350 and is fixed in place between a pair of L-shaped angles 31. In other words, the steel member 352 is fixed to the chute 14.

[0051] The load cell 353 is positioned between a steel member 351 fixed to the cylinder 350 and a steel member 252 fixed to the chute 14. When the cylinder 350 receives pressure from the concrete, the load cell 353 outputs a signal corresponding to that pressure. In other words, the load cell 353 measures the load (corresponding to the flow load) of the concrete flowing through the chute 14.

[0052] The laser displacement meter 34 is attached to the magnet stand 33 so as to face the concrete flowing through the chute 14. Further, the laser displacement meters 34 are provided upstream and downstream of the probe 35, respectively, in the flow direction (flowing direction) of the concrete. Among these, the laser displacement meter 34 provided upstream is also referred to as the laser displacement meter 34A, and the laser displacement meter 34 provided downstream is also referred to as the laser displacement meter 34B.

[0053] The laser displacement meter 34 has a laser irradiation unit (not shown) and a reflected laser reception unit (not shown), and measures the distance to the measurement object by receiving the laser irradiated from the laser irradiation unit and reflected by the measurement object with the reflected laser reception unit. In the present embodiment, the laser displacement meter 34 measures the top height of the concrete (corresponding to the flowing height) flowing through the chute 14.

[0054] Figs. 4A to 4C are explanatory diagrams of a method for measuring the top height of concrete by the laser displacement meter 34.

[0055] As shown in Fig. 4A, in a state where no concrete is flowing through the chute 14, the distance between each laser displacement meter 34 and the bottom of the chute 14 is measured. In Fig. 4A, the distances (measured values) are d1 both on the upstream side (laser displacement meter 34A) and the downstream side (laser displacement meter 34B). 4]

[0056] As shown in Fig. 4B, when concrete is flowing through the chute 14 and the slump is large, the concrete flows gently like a liquid. Therefore, the load received by the probe 35 is small, and the top height of the concrete becomes low. In Fig. 4B, the measured value on the upstream side (laser displacement meter 34A) is d2 (<d1), and the measured value on the downstream side (laser displacement meter 34B) is d2' (<d1). In this case, the top height of the concrete is obtained as d1 - d2 on the upstream side and d1 - d2' on the downstream side. When the slump is large, as shown in Fig. 4B, the difference between the measured value (d2) on the upstream side and the measured value (d2') on the downstream side is small, and the difference between the top height on the upstream side and the top height on the downstream side is also small.

[0057] Also, as shown in FIG. 4C, when concrete is flowing in the chute 14 and the slump is small, the probe 35 becomes an obstacle, and the concrete is likely to accumulate in front of the probe 35 (the upstream side of the flow). Therefore, the load received by the probe 35 is large, and the top height of the concrete in front of the probe 35 (the upstream side) becomes high. In FIG. 4C, the measured value d3 (<d1) on the upstream side (laser displacement meter 34A) is smaller than the measured value d3' (<d1) on the downstream side (laser displacement meter 34B). Also in this case, the top height of the concrete is obtained as d1 - d3 on the upstream side and d1 - d3' on the downstream side. When the slump is small, as shown in FIG. 4C, the measured value (d3) on the upstream side is smaller than the measured value (d3') on the downstream side. That is, the top height on the upstream side is likely to be high.

[0058] Although not shown here, the flow velocity of the concrete flowing in the chute 14 (corresponding to the flow rate) can also be measured using a Doppler-type non-contact flow velocity meter (for example, WJ7661 type RYUKAN manufactured by Yokogawa Electric Corporation). This non-contact flow velocity meter measures the flow velocity of rivers and the like using radio waves (microwaves), but it is also applicable to the flow of concrete. Although it is desirable to arrange the non-contact flow velocity meter perpendicular to the inclination of the chute 14 (the flow of concrete), if it cannot be arranged perpendicular, correction may be performed.

[0059] The outputs of the load cell 353, the laser displacement meter 34 (and the non-contact flow velocity meter) are transmitted to a terminal device (not shown) such as a personal computer (PC) or a tablet terminal via communication means such as a cable (wired) or wireless. This terminal device has a storage unit for storing data and programs, an arithmetic unit for performing various calculations based on the programs, a display unit for displaying measurement data (such as waveforms), a warning generation unit for generating warnings by sound or light emission, and the like. Then, the terminal device manages the measured data and generates a warning when the measured value reaches a predetermined value (threshold value).

[0060] <Regarding the relationship between slump and various measurement data> Figure 5A shows an example of measurement data when the slump is large (24.5 cm in this case), and Figure 5B shows an example of measurement data when the slump is small (9 cm in this case).

[0061] In both Figures 5A and 5B, the data is arranged from top to bottom in the order of load, height (height of the top of the concrete), and flow velocity. The horizontal axis of each graph represents time. The load is the measurement value obtained by the load cell 353 of probe 35, and the height is the value obtained from the measurements of the laser displacement meter 34 (upstream laser displacement meter 34A and downstream laser displacement meter 34B) (height of the top of the concrete) (see Figures 4B and 4C). The flow velocity is the value obtained by measuring the concrete flowing through the chute 14 using a non-contact Doppler flow meter.

[0062] When the slump is large, the concrete is soft and flows easily, resulting in a small load, low height, and high flow velocity, as shown in Figure 5A.

[0063] In contrast, when the slump is small, the concrete hardens, so the load (the force exerted by the concrete on the load cell 353 of probe 35) increases. Also, the height is higher than in Figure 5A, and it can be seen that the value on the upstream side (laser displacement meter 34A) is particularly large. Furthermore, as the concrete hardens, it becomes more difficult to flow, so the flow velocity is lower than in Figure 5A.

[0064] Figure 6 shows the relationship between slump and load, and Figure 7 shows the relationship between slump and the top height of the concrete. In Figure 7, the top height of the concrete flowing through the chute 14 upstream of the probe 35 (i.e., the measurement value of the laser displacement meter 34A) is shown. Figure 8 shows the relationship between slump and concrete flow velocity, and Figure 9 shows the relationship between the top height of the concrete and the load. Each figure shows the measurement results for each pumping speed. The pumping speed is the speed at which concrete is pumped from the pump truck 20, and can be set on the pump truck 20. Since it is necessary to supply concrete from the ready-mix concrete truck 10 to the pump truck 20 according to this pumping speed, the pumping speed is correlated with the supply speed of concrete from the ready-mix concrete truck 10 to the pump truck 20. In other words, the larger the pumping speed, the larger the supply speed of concrete from the ready-mix concrete truck 10 to the pump truck 20.

[0065] As shown in Figure 6, a larger slump results in a smaller load, and a smaller slump results in a larger load. Furthermore, the load increases with increasing pumping speed (supply speed).

[0066] Furthermore, as shown in Figure 7, a larger slump results in a lower top surface height of the concrete, while a smaller slump results in a higher top surface height. Additionally, a higher pumping speed (supply speed) leads to a higher top surface height.

[0067] Furthermore, as shown in Figure 8, a larger slump results in a faster concrete flow velocity through chute 14, while a smaller slump results in a slower flow velocity. Note that when the slump is large, the difference in flow velocity due to the pumping speed (supply speed) is significant, but as the slump decreases, the difference in flow velocity due to the pumping speed decreases, and at a slump of 9.5, the flow velocity is almost the same regardless of the pumping speed.

[0068] Furthermore, Figure 9 shows that there is a correlation between height and load. In other words, measuring the flow state of concrete can be done using either load or height alone. Also, from Figures 5A and 5B, it can be said that flow velocity is also correlated with load and height.

[0069] As such, there is a correlation between slump and each measured value. Therefore, by training an AI or similar system to learn the relationship between the slump at the time of concrete acceptance and the measurement data, subsequent measured values ​​can be converted (corresponded) to the slump value.

[0070] <Regarding methods for managing the fluidity of concrete> (Comparative example) Before describing this embodiment, a general control method (comparative example) that does not use the measuring unit 30 will be described.

[0071] Figure 10 is a flowchart of the method for controlling the fluidity of concrete (quality control method) in the comparative example.

[0072] First, an order for concrete is placed (S201). Then, when the ready-mix concrete truck 10 arrives at the site (S202), an acceptance inspection is conducted (S203). If the acceptance inspection fails (NO in S203), the concrete is returned or discarded (S204), and step S201, where the concrete is ordered, is repeated. Note that an acceptance inspection failure occurs when the slump or air content does not meet the specified standards. For example, if concrete with a slump of 18 cm is ordered and the acceptable range is ±2.5 cm, then concrete with a slump of 21 cm will fail and will be returned to the plant (or discarded).

[0073] If the acceptance inspection is passed (YES in S203), concrete pouring begins using concrete mixer truck 10 and pump truck 20 (S205). Also, a slump test is performed at appropriate intervals (for example, every 30 minutes) (S206). If the slump test result is NG (failure) (NO in S207), the remaining concrete is returned and disposed of (S204), and the process returns to the step of ordering concrete (step S201). If the slump test result is OK (pass) (YES in S207), a determination is made as to whether the pouring is complete or not (step 208). If the pouring is not complete (NO in S208), concrete pouring continues, and a slump test is performed at appropriate intervals. If it is determined in step S208 that the concrete pouring is complete (YES in S208), concrete pouring is stopped.

[0074] In this comparative example, the fluidity of the concrete is repeatedly evaluated by performing slump tests at appropriate intervals (for example, every 30 minutes). In this case, the more slump tests performed, the more reliable the quality becomes, but it is time-consuming. Furthermore, managing fluidity in real time would require performing tests many times, which is practically impossible. It is also possible to visually check the condition (fluidity) of the concrete flowing through the chute 14 of the ready-mix concrete truck 10, but this is subjective and requires the deployment of dedicated personnel.

[0075] (Embodiment) Figure 11 is a flowchart of the concrete fluidity control method (quality control method) in this embodiment. In this embodiment, a warning is issued when the slump falls below a predetermined value (for example, 9.0 cm). The following description will focus on the case of measuring load, but the same control method can be used when measuring the top surface height or flow velocity of the concrete.

[0076] Steps S101 to S105 correspond to steps S201 to S205 of the comparative example, so their explanation will be omitted. In this embodiment, when the concrete mixer truck 10 arrives at the site, the measuring unit 30 is attached to the chute 14 of the concrete mixer truck 10 (S106). Alternatively, the measuring unit 30 may be attached to the chute 14 of the concrete mixer truck 10 in advance. When measuring the concrete flow velocity, a non-contact Doppler flow meter is placed near the chute 14 (i.e., the concrete flow path).

[0077] Simultaneously with the start of concrete pouring, waveform measurement by load cell 353 begins (S107), and the acceptance inspection results (slump) and measured waveform (load) are calibrated using AI (machine learning, etc.) (S108) to obtain a reference value. In other words, a correspondence is made between the slump of the reference concrete (corresponding to the reference cement composition) and the load. Then, a threshold for issuing a warning is set (S109: corresponding to the threshold setting step). For example, as shown in Figure 6, there is a roughly linear relationship between load and slump, so if data is accumulated, the load (threshold) at which the slump becomes 9.0 can be set using AI, etc. (the amount of increase in load in relation to the decrease in slump can be estimated). This threshold is stored in the memory unit of the terminal device (not shown). Note that, as shown in Figure 6, the load depends on the concrete supply speed (pumping speed) to the pump truck 20, so it is desirable to change the threshold according to the supply speed.

[0078] Subsequently, the fluidity (in this case, load) of the concrete flowing through the chute 14 is checked (measured) by the load cell 353 (S110: corresponding to the measurement step). The terminal device compares the stored threshold (for example, the load threshold corresponding to a slump of 9.0) with the output of the load cell 353 (measurement data) and determines whether the measured value has reached the threshold (is less than the threshold) (S111: corresponding to the determination step). If the measured value reaches the threshold (for example, the value corresponding to a slump of 9.0) (NO in S111), the terminal device issues a warning, such as by generating a sound. If this warning is given (YES in S112), step S104 is executed to return and discard the remaining concrete.

[0079] If the measured value in step S111 does not reach the threshold (YES in S111), or if there is no warning in step S112 (NO in S112), a determination is made as to whether the concrete pouring is complete or not (step S113). If the concrete pouring is not complete (NO in S113), the process returns to step S110 and continues with the measurement and comparison. On the other hand, if the concrete pouring is complete (YES in S113), the concrete pouring and measurement are terminated.

[0080] As described above, in this embodiment, a measuring unit 30 (load cell 353) is attached to the chute 14 of the ready-mix concrete truck 10. The following steps are performed: measuring the flow state (load) of the concrete flowing through the chute 14 with the load cell 353 (S110), setting a threshold (S109), and determining the quality of the concrete by comparing the output of the load cell 353 with the threshold (S111).

[0081] This allows for the automatic measurement of concrete fluidity (in this example, load) and real-time management of concrete fluidity.

[0082] In this embodiment, the case of measuring the load of concrete flowing through the chute 14 of the ready-mix concrete truck 10 has been described, but the top height of the concrete or the flow velocity may also be measured. In this case as well, a threshold should be set and the measured value should be compared with the threshold. Alternatively, the fluidity of the concrete may be evaluated by combining the load, height, and flow velocity.

[0083] ===Other Examples=== The embodiments of the present invention have been described above, but these embodiments are intended to facilitate understanding of the present invention and are not intended to limit its interpretation. Furthermore, the present invention can be modified or improved without departing from its spirit, and it goes without saying that the present invention includes equivalents thereof. For example, the following modifications are possible.

[0084] The embodiments described above illustrate the case of controlling the fluidity of concrete, but are not limited to this and can be applied to other cement compositions (e.g., mortar).

[0085] Furthermore, in the above-described embodiment, the state of concrete flowing through the chute 14 of the concrete mixer truck 10 was measured, but the measurement is not limited to the chute 14; the same measurement may be performed by pouring concrete into an inclined member. For example, a member having an inclined surface (corresponding to an inclined section) may be placed between the chute 14 of the concrete mixer truck 10 and the hopper 22 of the pump truck 20, and a measuring unit 30 may be provided on the member to measure the flow state of concrete flowing through the inclined surface.

[0086] Furthermore, in the above-described embodiment, a laser displacement meter 34A was provided upstream of the probe 35 and a laser displacement meter 34B was provided downstream of the probe 35 as laser displacement meters 34 for measuring the concrete height, but at least a laser displacement meter 34A is sufficient. However, providing laser displacement meters 34 both upstream and downstream of the probe 35, as in this embodiment, can improve the accuracy of the evaluation. In addition, three or more laser displacement meters 34 may be provided (for example, an additional laser displacement meter may be provided between the probe 35 and the laser displacement meter 34B). [Explanation of Symbols]

[0087] 10 Concrete mixer truck, 12 Drum, 14 Chute, 20 pump trucks, 22 hoppers, 24 pumps, 26 concrete supply pipes, 30 Measuring section, 31 L-shaped angle, 32 Steel plate, 33 Magnetic stand, 34 Laser displacement meter (measuring instrument), 34A Laser displacement meter, 34B Laser displacement meter, 35. Probe (load detection unit, obstacle detection unit), 350 cylinder (cylindrical body), 351 steel material, 352 steel material (plate member), 353 Load cell (measuring meter),

Claims

1. The measuring unit is attached to the chute of the concrete mixer truck. A measurement step in which the flow state of the cement composition flowing through the chute is measured by a measuring instrument in the measuring unit without taking an image, A threshold setting step to set a threshold, A determination step in which the quality of the cement composition is determined by comparing the output of the measuring instrument with the threshold value, It has, The aforementioned flow state is the flow load, The aforementioned measuring instrument is a load cell, The measuring unit includes the load cell and has a load detection unit inserted into the cement composition flowing through the chute. The load detection unit outputs a signal corresponding to the pressure received from the cement composition, which is used as the output of the measuring instrument. The measurement step, the threshold setting step, and the determination step, The fluid load of the cement composition is automatically measured, and the fluidity of the cement composition is managed in real time. A method for quality control of a cement composition characterized by the following features.

2. A method for quality control of a cement composition according to claim 1, The threshold is determined based on the flow state of the standard cement composition relative to its slump. A method for quality control of a cement composition characterized by the following features.

3. A method for quality control of a cement composition according to claim 1 or 2, The load detection unit is A cylindrical body inserted into the aforementioned cement composition, A plate member, one end of which is fixed to the chute and the other end of which is inserted into the cylindrical body, It has, The load cell is provided between the cylindrical body and the plate member and outputs the signal in accordance with the pressure the cylindrical body receives from the cement composition. A method for quality control of a cement composition characterized by the following features.

4. A method for quality control of a cement composition according to claim 3, The aforementioned cylindrical body is cylindrical. A method for quality control of a cement composition characterized by the following features.

5. A method for quality control of a cement composition according to any one of claims 1 to 4, The threshold is changed according to the supply speed of the cement composition during placement. A method for quality control of a cement composition characterized by the following features.

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