JP6778023B2 - Pumping performance evaluation system for fresh concrete - Google Patents

Description

The present invention relates to a pumping performance evaluation system for fresh concrete, and more particularly, to a system for preventing blockage of the pumping path by evaluating the pumping performance of fresh concrete sent from a concrete pump truck. is there.

In construction where concrete must be placed away from the concrete pump truck, such as bridge superstructure, it is necessary to arrange a transport pipe to the concrete placement position and pump fresh concrete. Here, when the extension distance of the transport pipe is long, the transport pipe may be blocked depending on the quality of the fresh concrete to be pumped.

In the construction of concrete structures, blockages in transport pipes that occur during concrete placement increase the risk of causing defects (unfilled or cold joints) in the structure, which is a major factor in causing quality deterioration. In addition, there is a risk of an accident (transport pipe rupture) due to sudden blockage of the transport pipe. In addition, it takes a lot of labor and cost to restore and remove the blocked transportation pipe.

In order to deal with such inconvenience, by arranging two transport pipes, when one of the transport pipes is blocked, the current situation is to switch to the other transport pipe and pump fresh concrete. Is.

Further, a device for monitoring the blockage of a transport pipe for pumping fresh concrete has been proposed (see, for example, Patent Document 1). In the technique described in Patent Document 1, an acoustic emission sensor is attached to the outer wall side of the transport pipe, and the material of the fresh concrete is separated by detecting the frictional noise between the fresh concrete during pumping and the inner wall of the transport pipe. It is a device that determines whether or not it is present.

Specifically, the concrete material separation determination means determines whether or not the fresh concrete material is separated based on the friction sound detected by the acoustic emission sensor, and outputs the determination result to the monitoring result output means. It has become.

When the fresh concrete is in good condition and the aggregate is covered with mortar, the fresh concrete is smoothly pumped into the transport pipe, and the friction noise between the fresh concrete and the transport pipe is small. On the other hand, if the aggregate and the mortar are separated, it can be determined that the aggregate may collide with the inner wall of the transport pipe to increase the frictional force and cause the transport pipe to be blocked.

Japanese Unexamined Patent Publication No. 9-218183

The technique described in Patent Document 1 described above is used to determine the material separation of concrete (separation of aggregate and mortar) from a location where blockage is likely to occur (for example, a connection portion between a vent pipe and a straight pipe or a flexible hose). Fricatives are collected by a sensor provided at the connection part of the straight pipe) and sorted in descending order of volume. Then, the manager investigates whether or not the blockage trouble has occurred sequentially, and if the blockage trouble actually occurs, the route of the transportation pipe is changed by changing the mixing ratio of fresh concrete and the material used. It is said that it will take measures such as making it more appropriate.

However, such a method of controlling blockage of a transportation pipe is not realistic. That is, even if the technique described in Patent Document 1 is used, it is considered that it strongly affects the friction noise generated between the concrete and the transport pipe when the concrete is sent out, such as the concrete composition, the pumping speed, and the pumping path. Insufficient to make engineering decisions about coping with factors.

Even if it is possible to detect blockage at a position away from the pump truck, such as the connection between the vent pipe and the straight pipe or the connection between the flexible hose and the straight pipe, concrete that is already unsuitable for pumping (the possibility of causing blockage is extremely high). (High concrete) is filled in the transport pipe, and it is easily inferred that it will be extremely difficult to restart pumping after detection.

The present invention has been proposed in view of the above circumstances, and it is possible to prevent blockage of the pumping path by accurately and appropriately evaluating the pumping performance of fresh concrete delivered from the concrete pump truck. The purpose is to provide a pumping performance evaluation system for concrete.

The pumping performance evaluation system for fresh concrete of the present invention has the following features in order to achieve the above-mentioned object. That is, the fresh concrete pumping performance evaluation system of the present invention is a system for evaluating the pumping performance of fresh concrete sent from a concrete pump truck, and is a detector tube and a detection tube arranged in the pumping path of the fresh concrete. It is characterized by having a measuring means attached to the concrete and an evaluation means.

Detector tube has a reduced diameter portion whose inner diameter is reduced in diameter gradually along the pumping direction of the fresh concrete, on the downstream side of the pumping direction of the fresh concrete of the reduced diameter portion, the inner diameter along the pumping direction of the fresh concrete is gradually It has a diameter-expanded portion that expands the diameter.

The measuring means is a means for measuring the force generated when the fine aggregate or coarse aggregate contained in the fresh concrete comes into contact with the detection tube, which is attached to the detection tube , by using an accelerometer .

The evaluation means is a means for evaluating the pumping performance of fresh concrete and the possibility of blockage in the pumping path by using the acceleration measured by the measuring means.

In the pumping performance evaluation system for fresh concrete having the above-described configuration, the diameter-reduced portion has a ratio of the inner space cross-sectional area of the widest cross section to the narrowest cross section of 45% or more and 95% or less, and the widest cross section. The ratio of the inner diameter to the length of the reduced diameter portion is preferably 25 or less.

In the pumping performance evaluation system for fresh concrete having the above-described configuration, a diameter-reduced continuous portion having the same inner diameter as the diameter-reduced portion of the diameter-reduced portion is provided between the diameter-reduced portion and the diameter-expanded portion. It is possible.

Further, in the pumping performance evaluation system for fresh concrete having the above-described configuration, it is preferable that the detector tube is attached in the vicinity of the concrete pump truck.

Further, in the fresh concrete pumping performance evaluation system having the above-described configuration, it is preferable to mount the sensor below the horizontal position of the detector tube.

According to the fresh concrete pumping performance evaluation system according to the present invention, a detector tube having a load portion that gives a load to the fresh concrete pumping and a low load portion that gives a smaller load to the fresh concrete than the load portion is provided. By providing this, it is possible to create a state similar to that of different pumping loads in a short section in the actual pumping path of fresh concrete.

Further, by providing the detector tube, it is possible to create a situation in which the pumping load is different at an arbitrary location regardless of the type and combination of the pumping paths. The pumping path refers to a cylinder of a concrete pump truck, pipes and booms connected to the cylinder, a transport pipe for transporting fresh concrete to a place away from the concrete pump truck, and the like.

Then, since the pumping performance can be evaluated by using appropriate information for evaluating the pumping system from various data generated in the detector tube, accurate evaluation can be performed. In addition, the accuracy of the evaluation can be further improved by performing the evaluation using a plurality of data. Further, by defining the specifications of the reduced diameter portion of the detector tube, more accurate measurement can be performed.

Further, by installing a detection tube in the vicinity of the concrete pump truck, it is possible to know the pumping performance of fresh concrete pumped from the concrete pump truck at an early stage in the initial stage of pumping. Further, by mounting the sensor below the horizontal position of the detector tube, it is possible to reliably detect information on the pumping state of fresh concrete.

As described above, by using the pumping performance evaluation system for fresh concrete according to the present invention, it is possible not only to prevent blockage of the pumping path including the transportation pipe and to improve the work efficiency, but also to improve the quality of the structure. Can be enhanced. In addition, the safety of pumping work can be enhanced.

The block diagram of the functional means constituting the pumping performance evaluation system of fresh concrete which concerns on this invention. Explanatory drawing which shows the pumping path of fresh concrete. The schematic diagram which shows the structure of the detector tube. Explanatory drawing which shows the shape of the reduced diameter part. Explanatory drawing of test result of composition of fresh concrete and fresh property. A graph showing the relationship between the composition of fresh concrete in the detector tube and the peak value of the acceleration amplitude. The graph which shows the relationship between the composition of fresh concrete in a taper pipe and the peak value of an acceleration amplitude. The graph which shows the evaluation about the difference of the acceleration amplitude between a detection tube and a horizontal tube. A graph showing the relationship between the number of tamping times and the flow value. The graph which shows the relationship of the frequency with respect to the peak value of acceleration in a bent pipe and a horizontal pipe. The graph which shows the relationship of the frequency with respect to the peak value of acceleration in a taper pipe and a horizontal pipe. A graph showing the relationship between the frequency and the peak value of acceleration in the detector tube and the horizontal tube. The graph which shows the evaluation of the time passage by the difference of acceleration in a bent pipe and a horizontal pipe. A graph showing the evaluation of the passage of time due to the difference in acceleration between a tapered pipe and a horizontal pipe. A graph showing the evaluation of the passage of time due to the difference in acceleration between the detector tube and the horizontal tube. Explanatory drawing which shows the relationship between the composition and pumping speed of fresh concrete, and the amount of voltage per one stroke of a cylinder.

Hereinafter, embodiments of the pumping performance evaluation system for fresh concrete (hereinafter, abbreviated as pumping performance evaluation system) according to the present invention will be described with reference to the drawings. 1 to 4 show a pumping performance evaluation system according to an embodiment of the present invention, FIG. 1 is a block diagram of the pumping performance evaluation system, FIG. 2 is an explanatory diagram showing a pumping path of fresh concrete, and FIG. A schematic diagram showing the configuration of the detector tube, and FIG. 4 is an explanatory diagram showing the shape of the reduced diameter portion.

Further, FIG. 5 is an explanatory diagram of the test results of the blending of fresh concrete and the fresh properties, FIG. 6 is a graph showing the relationship between the blending of fresh concrete in the detector tube and the peak value of the acceleration amplitude, and FIG. 7 is a graph of the fresh concrete in the tapered pipe. A graph showing the relationship between the compounding and the peak value of the acceleration amplitude, FIG. 8 is a graph showing the evaluation of the difference in the acceleration amplitude between the detector tube and the horizontal tube, FIG. 9 is a graph showing the relationship between the number of tamping times and the flow value, and FIG. 10 is a vent. A graph showing the relationship of frequency with respect to the peak value of acceleration in the tube and the horizontal tube, FIG. 11 is a graph showing the relationship of frequency with respect to the peak value of acceleration in the tapered tube and the horizontal tube, and FIG. 12 is a graph showing the relationship between the peak acceleration in the detection tube and the horizontal tube. A graph showing the relationship of frequency with respect to a value, FIG. 13 is a graph showing an evaluation of time lapse due to a difference in acceleration between a bent pipe and a horizontal pipe, and FIG. 14 is a graph showing an evaluation of time lapse due to a difference in acceleration between a tapered pipe and a horizontal pipe. 15 is a graph showing the evaluation of the passage of time due to the difference in acceleration between the detection tube and the horizontal tube, and FIG. 16 is an explanatory diagram showing the relationship between the blending and pumping speed of fresh concrete and the amount of voltage per stroke of the cylinder. ..

<Overview of pumping performance evaluation system>
As shown in FIGS. 1 and 2, the pumping performance evaluation system 10 according to the embodiment of the present invention is a system for evaluating the pumping performance of fresh concrete delivered from the concrete pump truck 100, and is a system for evaluating the pumping performance of fresh concrete. The detector tube 120 is provided in a path and has a load portion that applies a load to the pumping of fresh concrete and a low load portion that exerts a smaller load on the pumping of fresh concrete as compared with the load portion.

The pumping path of fresh concrete is a path from the cylinder 110 of the concrete pump truck 100 to the driving position, and is a pipe or boom portion (not shown) communicatively connected to the cylinder 110 and the cylinder 110 of the concrete pump truck 100. , Various devices and members such as a transport pipe 40 for transporting fresh concrete to a place separated from the concrete pump truck 100 serve as a pumping route.

Further, based on the measuring means 20 for measuring the force generated when the fine aggregate (sand) and the coarse aggregate (gravel) contained in the fresh concrete come into contact with the detection tube 120, and the information measured by the measuring means 20. Therefore, it is provided with an evaluation means 30 for evaluating the pumping performance of fresh concrete and the possibility of blockage in the pumping path such as the transport pipe 40.

In general building construction, fresh concrete is often driven directly from the concrete pump truck 100, and blockages occur in the pumping path such as pipes and booms (not shown) equipped in the concrete pump truck 100. Possibility needs to be evaluated. In this case, the detection tube 120 is attached to the cylinder 110, the pipe, and the boom portion.

Further, in a construction such as a bridge superstructure where concrete must be placed at a place away from the concrete pump truck 100, a transport pipe 40 is arranged up to the concrete placing position and fresh concrete is pumped. In this case, as a pumping path for fresh concrete, there is a cylinder 110 for feeding fresh concrete from the concrete pump truck 100 and a transport pipe 40 communicating with the cylinder 110, and the detection pipe 120 is connected to such a pumping path. Install.

Further, as a type of the transport pipe 40, there are a straight pipe, a vent pipe, a flexible pipe and the like, and the pumping path of fresh concrete is not constant incline and straight like horizontal, uphill, downhill, bent and the like. Further, the fresh concrete to be pumped has a different frictional resistance value in the pumping path depending on the mixing ratio of cement, water, fine aggregate, coarse aggregate, other additives and the like.

The pumping performance evaluation system 10 according to the embodiment of the present invention is a system capable of responding to the fact that concrete must be placed in a wide variety of modes at each site, and can be directly applied using the detector tube 120. By creating a state similar to a pipe, a vent pipe, a flexible pipe, etc., and using the measurement information measured by the detection pipe 120, the pumping performance of fresh concrete sent from the concrete pump truck 100 is accurately and appropriately evaluated. , It is possible to prevent blockage in the pumping path such as the transport pipe 40.

<Detective tube>
The detector tube 120 has a load portion that applies a load to the pumping of fresh concrete, and a low load portion that applies a smaller load to the fresh concrete than the load portion. That is, as shown in FIGS. 3A to 3E, the detection tube 120 has a diameter-reduced portion 121 whose inner diameter gradually decreases along the pumping direction of the fresh concrete, and the inner diameter gradually increases. It is composed of an enlarged diameter portion 123, the enlarged diameter portion 123 is a low load portion, and the reduced diameter portion 121 is a load portion.

Further, a diameter-reduced continuous portion 122 may be provided between the diameter-reduced portion 121 and the diameter-expanded portion 123 so that the inner diameter is continuous with the same inner diameter as the portion with the smallest inner diameter (a). And the diameter-expanded portion 123 may be continuous (b), and in the pumping direction of fresh concrete, the same inner diameter as the portion having the largest inner diameter is continuous on the front side or the rear side of the diameter-expanded portion 123. The diameter-expanded continuous portion 124 may be provided (c, d), and in the pumping direction of fresh concrete, the same inner diameter as the portion having the largest inner diameter is continuous on the front side and the rear side of the diameter-expanded portion 123. The diameter-expanded continuous portion 124 may be provided (e).

As described above, the load portion of the detection tube is a reduced diameter portion whose inner diameter gradually decreases in the pumping direction of fresh concrete, and the reduced diameter portion has the widest cross section and the largest diameter as shown in FIG. It is preferable that the ratio of the inner space cross-sectional area to the narrow cross section is 45% or more and 95% or less, and the ratio of the inner diameter of the widest cross section to the length of the reduced diameter portion is 25 or less.

<Measuring means>
The measuring means 20 includes a vibrometer, an accelerometer, a sensor that generates electricity (for example, a sensor that generates electricity in connection with vibration, such as a power generation element or a piezoelectric element), a displacement meter, a strain gauge, a pressure gauge, and a flow rate. Use one or more of a meter and an accelerometer (sensors related to deformation and pressure). In each sensor, fine aggregates and coarse aggregates contained in fresh concrete come into contact with the transport pipe 40, the cylinder 110 of the concrete pump truck 100, and the pipes and booms (not shown) equipped in the concrete pump truck 100. It is a device for measuring the force generated at the time of performing, and the measurement information is used for the evaluation in the evaluation means 30. In the present embodiment, in particular, the measuring means 20 is attached to the detection tube 120, but the accuracy of the evaluation in the evaluation means 30 can be further improved by attaching the measuring means 20 to other places (appropriate places of the pumping path).

The measurement by the displacement meter or the strain meter is, for example, the measurement in the circumferential direction and the axial direction of the transport pipe 40. Further, the information measured by the measuring means 20 relates to a force generated when the fine aggregate or coarse aggregate contained in the fresh concrete comes into contact with the cylinder 110, the pipe, or the boom portion of the transport pipe 40 or the concrete pump truck 100. It is a thing. Further, when evaluating the information measured by the measuring means 20, in addition to the measured value itself, information such as a temporal change and a shape may be used.

<Evaluation means>
The evaluation means 30 acquires the information measured by the measuring means 20 and evaluates according to the type of each information, thereby determining the pumping performance of fresh concrete and the possibility of blockage in the pumping path such as the transport pipe 40. evaluate. The measuring means 20 is composed of at least one type or a combination of two or more types of each of the above-mentioned sensors, and the information used for evaluation includes waveforms, frequencies, accelerations, amplitudes, currents, voltages, resistances, etc. acquired by these sensors. Energy, displacement, strain, pressure, flow rate, flow velocity.

By combining and measuring information obtained from a plurality of types of sensors, it is possible to achieve high measurement accuracy and evaluation accuracy. For example, by using the displacement amount of the pumping path of the transport pipe 40 or the like in addition to the voltage value or acceleration, the pumping load for the pumping path of the transport pipe 40 or the like and the pumping speed of fresh concrete can be discriminated.

The evaluation means 30 can be configured by a personal computer, a microcomputer, a tablet-type mobile terminal, and an application program installed therein. Further, since an input means 50 such as a keyboard and a mouse and an output means 60 such as a display device, a printer, an amplifier and a speaker can be connected to a personal computer or a microcomputer as accessory devices, an instruction signal can be input and evaluated. Data can be output.

Furthermore, the information output by the sensor may change depending on the usage time, usage location, and the like. Therefore, it is preferable to perform calibration as appropriate to correct the information according to the usage status of the sensors constituting the evaluation means 30.

Further, each sensor constituting the measuring means 20 and the evaluation means 30 may be connected by wire using an electric cable, or may be wirelessly connected by using radio waves, infrared rays, or a relay device. Whether to connect by wire or wirelessly may be appropriately selected according to the connection state between the sensor mounting position and the evaluation means 30, that is, the distance, the presence or absence of a shield, and the like.

<Arrangement position of detector tube>
The arrangement position of the detection tube 120 is not particularly limited, but as shown in FIG. 2, it is preferably in the vicinity of the concrete pump truck 100. By attaching the detection tube 120 in the vicinity of the concrete pump truck 100, it is possible to know the pumping performance of fresh concrete pumped from the concrete pump truck 100 at an early stage in the initial stage of pumping.

Here, when an attempt is made to obtain a highly accurate waveform using each sensor, the amount of data can be reduced in a region where the frequency (frequency) is low, and handling as information processing is improved. Then, when the amount of data is reduced, it becomes possible to remotely collect data by wireless communication. Furthermore, there is an advantage that a sensor having a low frequency band can be easily obtained.

<Evaluation of pumping performance>
Depending on the operating state of the pump (cylinder 110), pulsation occurs in the fresh concrete that is pumped through the pumping path such as the cylinder 110 or the transport pipe 40, and the waveform, frequency, which is the measurement information of the sensor attached to the detection pipe 120, Acceleration, amplitude, current, voltage, resistance, energy, displacement, strain, pressure, flow rate, and flow velocity change. Further, by attaching the measuring means 20 to the detection pipe 120 having the load portion and the low load portion having different pumping loads of fresh concrete and acquiring various information, various shapes such as a straight pipe, a vent pipe, a flexible pipe, etc. It is possible to simulate the pumping path of a certain transport pipe 40 or the like. Therefore, it is possible to acquire the information necessary for the pumping performance evaluation of fresh concrete in real time according to the situation at the site.

Further, by combining the information acquired from the above-mentioned plurality of types of sensors, various calculations can be performed in real time, and the pumping performance of the fresh concrete can be accurately evaluated in consideration of the pumping speed of the fresh concrete.

As described above, the waveform, frequency, acceleration, amplitude, current, voltage, resistance, energy, displacement, strain, pressure, flow rate, and flow velocity, which are the measurement information of the sensor, are used for the evaluation. For example, as the pumping speed of fresh concrete increases, the pumping pressure in the pumping path such as the transport pipe 40 tends to increase, and the acceleration value tends to increase. Further, in the case of fresh concrete having a composition in which blockage is likely to occur, the shape of acceleration tends to show an irregular shape due to more turbulence as compared with a composition in which blockage is unlikely to occur and is smoothly pumped.

Further, as the pumping speed of fresh concrete increases, the acceleration and amplitude tend to increase. Further, in the case of fresh concrete having a composition that is likely to cause blockage, the acceleration and amplitude tend to be higher than those of a composition that is less likely to cause blockage and is smoothly pumped. In addition, the acceleration and amplitude tend to decrease as the slump increases.

In addition, the pumping performance of fresh concrete is evaluated by using the difference and ratio of the peak values measured between the straight pipe and the vent pipe (by comparing the data obtained under different pumping loads). You can also do it. In the present embodiment, by providing the detection tube 120, a situation in which the pumping load differs at an arbitrary location is created regardless of the type and combination of the transport pipe 40 and the like in the pumping route.

In this way, since there is a correlation between waveform, frequency, acceleration, amplitude, current, voltage, resistance, energy, displacement, strain, pressure, flow rate, flow velocity and the pumping performance of fresh concrete, one type of sensor can be used. By combining the acquired information or the information acquired from a plurality of types of sensors, the pumping performance of fresh concrete can be evaluated accurately and appropriately.

<Evaluation of pumping performance of fresh concrete>
The test results regarding the pumping performance evaluation of fresh concrete using the pumping performance evaluation system 10 according to the present embodiment will be described with reference to FIGS. 5 to 16. FIGS. 5 to 9 show the detection of the difference in the type of fresh concrete by the detection pipe and the performance difference between the detection pipe and other pipes. In addition, FIGS. 10 to 14 show the effectiveness of the detector tube and the method of blockage management (evaluation of the passage of time). Further, FIG. 16 shows the relationship between the compounding and the electrical energy obtained by converting the resistance at the time of pumping into a voltage amount.

As is clear from FIGS. 5 to 16, by using the pumping performance evaluation system 10 according to the present embodiment, the pumping performance of fresh concrete can be accurately evaluated. Therefore, according to the pumping performance evaluation system 10 according to the present embodiment, it is possible to prevent the pumping path from being blocked and improve the work efficiency. Furthermore, since the pumping performance of the fresh concrete is accurately evaluated, the quality of the structure using the fresh concrete can be improved.

10 Pumping performance evaluation system 20 Measuring means 30 Evaluation means 40 Transport pipe 50 Input means 60 Output means 100 Concrete pump car 110 Cylinder 120 Detection pipe 121 Reduced diameter part 122 Reduced diameter continuous part 123 Expanded diameter part 124 Expanded diameter continuous part

Claims (5)

It is a system for evaluating the pumping performance of fresh concrete sent from a concrete pump truck.
The diameter-reduced portion, which is arranged in the pumping path of the fresh concrete and whose inner diameter is gradually reduced along the pumping direction of the fresh concrete, and the reduced diameter portion downstream of the pumping direction of the fresh concrete. In addition to being provided with a detector tube having an enlarged diameter portion whose inner diameter gradually increases along the pumping direction of fresh concrete,
A measuring means for measuring the force generated when the fine aggregate or coarse aggregate attached to the detection tube and contained in the fresh concrete comes into contact with the detection tube using an accelerometer.
An evaluation means for evaluating the pumping performance of the fresh concrete and the possibility of blockage in the pumping path using the acceleration measured by the measuring means.
A pumping performance evaluation system for fresh concrete, which is characterized by being equipped with. In the reduced diameter portion, the ratio of the inner space cross-sectional area between the widest cross section and the narrowest cross section is 45% or more and 95% or less, and the ratio of the inner diameter of the widest cross section to the length of the reduced diameter portion is 25. The pumping performance evaluation system for fresh concrete according to claim 1, wherein the system is as follows. A continuous diameter-reduced portion having the same inner diameter as the portion with the smallest inner diameter of the reduced diameter portion is provided between the reduced diameter portion and the expanded diameter portion.
The pumping performance evaluation system for fresh concrete according to claim 1 or 2. The pumping performance evaluation system for fresh concrete according to any one of claims 1 to 3, wherein the detector tube is attached in the vicinity of the concrete pump truck. The pumping performance evaluation system for fresh concrete according to any one of claims 1 to 4, wherein the sensor is mounted below the horizontal position of the detector tube.

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