A concrete pump delivery cylinder filling rate test platform and test method

Abstract

The present invention discloses an experimental platform for testing the filling rate of a concrete pump delivery cylinder and a testing method thereof. The platform includes a hydraulic station and its control system, a displacement sensor, a hydraulic sensor, an oil pipe, a concrete suction device, a cylinder cover, a sealing gasket, a measuring cylinder, a hopper and its movable bracket, a high-speed camera and a vibration table. The hydraulic station controls the movement of the oil cylinder piston through a throttling solenoid valve, driving the concrete piston to absorb and pump materials; the concrete cylinder adopts a transparent material for easy observation during the natural filling rate test, and a steel material during the pressure filling rate test. The testing method includes pre-experimental preparation, natural suction filling rate test and pressure filling rate test, and the natural filling rate and pressure filling rate are calculated respectively through displacement and pressure monitoring, high-speed video recording and measuring with a measuring cylinder. The present invention can accurately test the filling rate, reveal its correlation with the pumping pulse, improve the visualization and controllability of the test process, and is suitable for testing various working conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete equipment testing, and relates to a concrete pump delivery cylinder filling rate testing experimental platform and a testing method thereof. Background Art

[0002] As an efficient and reliable method of delivering concrete, concrete pumping technology has been widely used in modern engineering construction, including construction projects, foundation projects, water conservancy projects, road projects, and municipal engineering. Through concrete pumping technology, concrete produced by mixing plants can be quickly and continuously delivered to the construction site, which not only significantly improves construction efficiency but also reduces the risks of manual operation, making the entire construction process safer and more controllable. With the increasing demand for efficient construction and high-quality concrete in the construction industry, the importance of concrete pumping technology in practical applications has become increasingly prominent. However, during the concrete pumping process, the problem of pumping pulse has always been one of the key factors affecting its performance and stability. The generation of pumping pulse is closely related to the filling rate of the concrete pump delivery cylinder.

[0003] During concrete pumping, the filling rate of the concrete cylinder directly determines the efficiency and stability of material suction and pumping. The filling rate refers to the ratio of the actual volume of concrete filled in the concrete cylinder during the suction process to its theoretical maximum capacity. Research has shown that achieving the ideal filling rate during the concrete cylinder suction process is often difficult due to the combined influence of concrete rheological properties (such as viscosity, fluidity, and water-cement ratio) and the operating characteristics of the pumping equipment itself (such as piston speed and suction port design). Specifically, the concrete suction process can result in low or unstable filling rates due to factors such as uneven particle distribution, air bubble incorporation, and suction resistance. This change in filling rate not only affects pumping efficiency but also causes significant pressure fluctuations during the reciprocating piston movement, known as pumping pulses. Pumping pulses can cause pipeline vibration, discontinuous delivery, and even adversely affect construction quality. Therefore, in-depth research on the variation of the concrete cylinder filling rate and its impact on pumping pulses is crucial for optimizing the structural design of concrete pumping equipment and improving pumping performance.

[0004] Currently, research on concrete pumping technology, both domestically and internationally, focuses on optimizing the mechanical structure of pumping equipment, improving hydraulic systems, and designing concrete mix proportions. For example, improving the control accuracy of the hydraulic system can reduce the amplitude of the pumping pulse to a certain extent; adjusting the concrete's water-cement ratio and aggregate grading can improve its fluidity, thereby indirectly increasing the filling rate. However, a systematic experimental platform and method for directly testing and quantitatively analyzing the core parameter of the concrete cylinder filling rate is still lacking. Traditional testing methods rely on theoretical calculations or indirect measurements, such as inferring the filling rate by comparing the pumping flow rate to the theoretical flow rate. However, this method cannot accurately reflect the actual filling state of concrete during the suction process, especially under different operating conditions such as natural suction and pressure filling. Furthermore, existing research lacks methods to observe the patterns of air incorporation during filling rate changes, which hinders the comprehensive understanding of the intrinsic connection between filling rate and pumping pulses.

[0005] Existing experimental platforms that can simultaneously meet both natural and pressure filling rate testing requirements are currently lacking. The natural filling rate primarily reflects the degree of concrete filling achieved without external pressure, relying on its own fluidity and the suction force of the suction device. The pressure filling rate, on the other hand, relates to the state of concrete being forcibly filled into the concrete cylinder under a specific hydraulic pressure. Due to the different mechanisms of these two filling methods, their impact on pumping pulses differs significantly. For example, during natural filling, air may be incorporated into the concrete as large bubbles, while during pressure filling, air may be evenly distributed as tiny bubbles, affecting the concrete's density and pumping stability. However, most current experimental equipment can only simulate a single operating condition, making it difficult to measure and compare filling rates in multiple dimensions. Furthermore, existing equipment also has limitations in observational methods, such as the lack of intuitive recording tools such as high-speed cameras, which cannot capture real-time changes in the concrete state during the filling process. These technical gaps limit in-depth research on concrete cylinder filling rate characteristics and their relationship to pumping pulses, hindering the effective resolution of related issues. Summary of the Invention

[0006] In view of this, the present invention provides a concrete pump delivery cylinder filling rate test experimental platform and testing method. The experimental platform can realize the accurate testing of the natural suction filling rate and pressure filling rate of the concrete cylinder, and comprehensively monitor the testing process through multiple sensors and high-speed cameras, thereby providing reliable experimental support for studying the pulse characteristics of concrete pumping.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A concrete pump delivery cylinder filling rate test platform, including a hydraulic station, a control system, a concrete suction device, a cylinder cover, a sealing gasket, a hopper, and a movable bracket;

[0009] The concrete suction device includes an oil cylinder, a water washing tank, a concrete cylinder, an oil cylinder piston, a piston rod, a connecting shaft, a concrete piston, and a fixed base; the oil cylinder and the concrete cylinder are connected via a water washing tank, and the water washing tank and the concrete cylinder are conductive and can be used to clean the concrete cylinder after testing; the piston rod is slidably arranged in the oil cylinder through the oil cylinder piston, and the concrete piston is slidably arranged in the concrete cylinder; one end of the connecting shaft passes through the water washing tank and is connected to the concrete piston, and the other end is connected to the piston rod;

[0010] The oil cylinder is connected to the hydraulic station through an oil pipe. A displacement sensor and a hydraulic pressure sensor are provided on the oil cylinder. Both the displacement sensor and the hydraulic pressure sensor are connected to the control system to obtain the displacement and hydraulic pressure information of the piston rod in the oil cylinder and control the movement of the piston rod;

[0011] The concrete cylinder is provided with a suction port at one end away from the oil cylinder, and a detachable cylinder cover is provided on the suction port, and the cylinder cover seals the suction port with a sealing gasket; the hopper is provided on a movable bracket, and the hopper is used to hold concrete. The hopper is provided with a hopper opening, and the hopper opening can be docked with the suction port by moving the movable bracket;

[0012] The control system controls the piston rod to drive the concrete piston to move, thereby achieving material suction and pumping of the concrete cylinder.

[0013] Furthermore, the experimental platform also includes a measuring cylinder and a vibration table. The measuring cylinder is used to receive the concrete pumped out of the concrete cylinder, and the vibration table is used to vibrate and expel the air from the concrete in the measuring cylinder.

[0014] Furthermore, the experimental platform also includes a high-speed camera, which is used to record the material suction and pumping processes.

[0015] Furthermore, the concrete cylinder is made of transparent material during the natural filling rate test, and is made of a common steel concrete cylinder during the pressure filling rate test.

[0016] Furthermore, the hydraulic station includes an oil pump, a throttle solenoid valve, an oil tank, a relief valve, and a pressure gauge; the oil pump on the oil tank is connected to the oil cylinder through an oil pipe, and the throttle solenoid valve controls the forward and backward movement of the oil cylinder piston in the oil cylinder, and then drives the concrete piston in the concrete cylinder through the connecting shaft to realize concrete suction and pumping.

[0017] A concrete pump cylinder filling rate test method based on the above-mentioned experimental platform includes pre-experimental preparation and requirements, natural suction filling rate test method and pressure filling rate test method, wherein:

[0018] Pre-experimental preparation and requirements include the following steps:

[0019] (1) Select the concrete cylinder material according to the experiment type. Transparent material is used for natural filling rate test, and steel material is used for pressure filling rate test.

[0020] (2) Determine the diameter of the concrete cylinder and select a matching concrete piston;

[0021] (3) Connect the concrete cylinder and the water washing tank, connect the concrete piston to the connecting shaft, and assemble the experimental platform;

[0022] (4) Extend the suction port completely into the hopper opening to fully wet the concrete cylinder and hopper;

[0023] (5) Open the hydraulic station, adjust the overflow valve to set the maximum hydraulic oil pressure P, control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, and push the cylinder piston forward to the initial position. At this time, the concrete piston is at the suction port position;

[0024] (6) Seal the concrete cylinder with a cylinder cover and a sealing gasket to prevent the concrete from entering the concrete cylinder prematurely;

[0025] (7) Load concrete into the hopper in an amount that ensures the lowest point of the concrete after suction is higher than the highest point of the hopper opening, and the loading amount is the same for different water-cement ratios;

[0026] The natural inhalation fill rate test method includes the following steps:

[0027] (1) The stroke of the oil cylinder piston is set by adjusting the throttle solenoid valve and displacement sensor through the control system, and the theoretical maximum filling volume V0 of the concrete cylinder is calculated;

[0028] (2) After loading is completed, open the cylinder cover and gasket;

[0029] (3) Turn on the data acquisition system of the displacement sensor and hydraulic sensor to monitor the displacement changes of the cylinder piston and the hydraulic oil pressure changes;

[0030] (4) Turn on the high-speed camera to monitor the concrete cylinder's suction process, concrete state, and bubble changes during the suction process;

[0031] (5) Control the throttle solenoid valve to inject hydraulic oil into the front of the cylinder, push the cylinder piston back to the predetermined stroke position, and complete the material suction;

[0032] (6) After the suction is completed, close the concrete cylinder with the cylinder cover and gasket, and then remove the hopper;

[0033] (7) Place the measuring cylinder below the suction port;

[0034] (8) Open the cylinder head and gasket;

[0035] (9) Turn on the high-speed camera to monitor the changes of concrete and bubbles in the concrete cylinder during the pumping process, as well as the state and volume changes of the concrete pumped into the measuring cylinder;

[0036] (10) Control the throttle solenoid valve to inject hydraulic oil into the rear of the oil cylinder, and pump out the concrete in the concrete cylinder until the concrete piston moves to the suction port position; the pumping process is monitored by a high-speed camera, and the changes in the concrete and bubbles in the concrete cylinder and the state and volume changes of the concrete pumped into the measuring cylinder;

[0037] (11) Start the vibration table and fully vibrate the concrete pumped into the measuring cylinder until the volume V1 is reached without large-scale air;

[0038] (12) Calculate the natural suction filling rate of the concrete cylinder under the natural suction mode under the same piston stroke and the same rheological properties of concrete

[0039] The pressure fill rate test method includes the following steps:

[0040] (1) The theoretical maximum stroke L0 of the cylinder piston is set by adjusting the throttle solenoid valve and displacement sensor through the control system;

[0041] (2) After loading is completed, open the cylinder cover and gasket;

[0042] (3) Turn on the data acquisition system of the displacement sensor and hydraulic sensor to monitor the displacement changes of the cylinder piston and the hydraulic oil pressure changes;

[0043] (4) Control the throttle solenoid valve to inject hydraulic oil into the front of the cylinder, push the cylinder piston back to the predetermined stroke position, and complete the material suction;

[0044] (5) After the suction is completed, close the concrete cylinder with the cylinder cover and gasket and remove the hopper;

[0045] (6) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, pushing the cylinder piston forward. When the hydraulic sensor detects that the pressure reaches the maximum value P, the forward distance is recorded as ΔL, and the oil injection is stopped;

[0046] (7) Place the measuring cylinder below the suction port;

[0047] (8) Open the cylinder head and gasket;

[0048] (9) Turn on the high-speed camera and monitor the changing state of the concrete material and the internal bubbles in the concrete cylinder during the pumping process, the falling state of the concrete material during the process of being pumped from the concrete cylinder to the measuring cylinder, and the volume change of the pumped concrete material;

[0049] (10) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, gradually pumping out the concrete sucked into the concrete cylinder until the concrete is completely pumped out and the concrete piston moves to the suction port position.

[0050] (11) Calculate the pressure filling rate of concrete under natural suction mode with the same piston stroke and the same rheological properties at different pressures P.

[0051] Furthermore, in the pressure filling rate test, different hydraulic oil pressures P were set by adjusting the relief valve, and the filling rate changes under different pressures were recorded.

[0052] Furthermore, by replacing concrete cylinders with different cylinder diameters and concrete with different rheological properties, the test was repeated to analyze the changing pattern of the filling rate.

[0053] Furthermore, by comparing the monitoring data of the displacement sensor and hydraulic sensor with the records of the high-speed camera, the air mixing pattern during the suction process and its influence on the filling rate were analyzed.

[0054] The beneficial effects of the present invention are:

[0055] 1. This invention addresses the lack of systematic filling rate testing in existing technologies by designing an experimental platform that integrates both natural suction filling rate and pressure filling rate testing. This platform can simulate concrete filling processes under both no external pressure and a specific pressure, respectively. The testing method, incorporating measurement tools such as displacement sensors, hydraulic sensors, and graduated cylinders, accurately calculates the filling rate, providing reliable data support for studying the filling characteristics of concrete during pumping.

[0056] 2. The experimental platform of this invention utilizes a transparent concrete cylinder (for natural filling rate testing) and a high-speed camera to record the concrete's state changes and bubble distribution during the suction process in real time, visually revealing the patterns of air incorporation. This visualization overcomes the limitations of traditional indirect measurement methods, which cannot accurately reflect the filling state. Furthermore, the hydraulic station and its control system precisely adjust the piston stroke and hydraulic pressure through a throttling solenoid valve and a relief valve, making the test conditions more controllable and the experimental results more reproducible and scientific.

[0057] 3. By comparing filling rate variations under different cylinder diameters, hydraulic pressures, and concrete rheological properties, combined with analysis of displacement and pressure data during suction and pumping, this paper systematically studies the impact of filling rate on pumping pulses. This provides a theoretical basis and technical guidance for resolving pulse problems caused by insufficient filling rate during pumping, helping to optimize the performance of concrete pumping equipment.

[0058] 4. This invention provides a scientific filling rate test method, providing an experimental basis for the structural design of concrete pumping equipment, hydraulic system improvements, and concrete mix optimization. This research result can effectively reduce pipeline vibration and delivery discontinuity caused by pumping pulses, improve construction efficiency and concrete pouring quality, and thus promote the further development of concrete pumping technology in the construction industry.

[0059] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0061] Figure 1 Schematic diagram of a concrete pump delivery cylinder filling rate test platform in an embodiment of the present invention.

[0062] Figure 2 for Figure 1 Schematic diagram of the hydraulic station and control system.

[0063] Figure 3 for Figure 1 Schematic diagram of the concrete suction device.

[0064] Figure 4 for Figure 1 Schematic diagram of the middle hopper and movable bracket.

[0065] Figure numerals: 1-hydraulic station and its control system; 2-displacement sensor; 3-hydraulic sensor; 4-oil pipe; 5-concrete suction device; 6-cylinder head; 7-sealing gasket; 8-measuring cylinder; 9-hopper and its movable bracket; 10-high-speed camera; 11-vibrating table; 101-oil pump; 102-throttling solenoid valve; 103-oil tank; 104-overflow valve; 105-pressure gauge; 501-oil cylinder; 502-water washing tank; 503-concrete cylinder; 504-oil cylinder piston; 505-piston rod; 506-connecting shaft; 507-concrete piston; 508-fixed base; 509-suction port; 510-oil filling port; 511-oil filling port; 901-hopper; 902-hopper opening; 903-bracket; 904-pulley. DETAILED DESCRIPTION

[0066] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0067] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0068] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0069] like Figure 1 As shown, the present invention provides a concrete pump cylinder filling rate test experimental platform mainly including a hydraulic station and its control system 1, a displacement sensor 2, a hydraulic sensor 3, an oil pipe 4, a concrete suction device 5, a cylinder cover 6, a sealing gasket 7, a measuring cylinder 8, a hopper and its movable bracket 9, a high-speed camera 10, and a vibration table 11.

[0070] like Figure 2 As shown, the hydraulic station and its control system 1 includes an oil pump 101, a throttle solenoid valve 102, an oil tank 103, a relief valve 104, a pressure gauge 105, etc. The hydraulic station and its control system 1 is connected to the concrete suction device 5 via an oil pipe 4. The throttle solenoid valve 102 automatically controls the hydraulic oil to be injected into the front or rear oil pipe 4, thereby controlling the forward and backward movement of the cylinder piston 504 in the oil cylinder 501. The connecting shaft 506 then drives the concrete piston 507 in the concrete cylinder 503 to suction and pump concrete.

[0071] like Figure 3As shown, the concrete suction device 5 is equipped with a displacement sensor 2, a hydraulic sensor 3, an oil cylinder 501, a water washing tank 502, a concrete cylinder 503, an oil cylinder piston 504, a piston rod 505, a connecting shaft 506, a concrete piston 507, a fixed base 508, a suction port 509, an oil filling port 510, and an oil filling port 511. The water washing tank 502 connects the oil cylinder 501 and the concrete cylinder 503, typically using bolts to ensure a secure connection and easy disassembly. The concrete cylinder 503 is made of a transparent material during the natural filling rate test, allowing the suction process and concrete conditions to be observed and recorded. A conventional steel concrete cylinder is used during the pressure filling rate test.

[0072] like Figure 4 As shown, the hopper and its movable bracket 9 include a hopper 901, a hopper opening 902 for the concrete cylinder 503 to extend into, a bracket 903, and a pulley 904. The design of the pulley 904 allows the hopper 901 to be easily moved away after the concrete cylinder 503 completes the material suction, so as to carry out the next step of the pumping experiment.

[0073] The cylinder cover 6 and the sealing gasket 7 are used for the experiment of measuring the pressure filling rate of the concrete cylinder; the measuring cylinder 8, the hopper and its movable bracket 9 and the high-speed camera 10 are used for the experiment of measuring the natural suction filling rate and the pressure filling rate of the concrete cylinder; the vibration table 11 is used for the experiment of measuring the suction filling rate.

[0074] The specific implementation plan and operation steps of the experiment are shown in 2. Experimental method for testing the filling rate of the concrete pump delivery cylinder.

[0075] Experimental method for testing the filling rate of concrete pump delivery cylinder

[0076] Preparation and requirements before the experiment:

[0077] (1) First, determine the type of experiment to be conducted (natural filling rate test experiment or pressure filling rate test experiment). In the natural filling rate test experiment, the concrete cylinder 503 is made of transparent material, usually acrylic material; in the pressure filling rate test experiment, a common ordinary steel concrete cylinder is used.

[0078] (2) Determine the cylinder diameter of the concrete cylinder 503 required for the experiment and select a concrete piston 507 of appropriate size.

[0079] (3) Connect the concrete cylinder 503 and the water washing tank 502 respectively, connect the concrete piston 507 to the connecting shaft 506, and the concrete pump delivery cylinder filling rate test experimental platform is assembled. Figure 1 The status shown.

[0080] (4) The suction port 509 of the concrete cylinder 503 is completely extended into the hopper opening 902 to fully wet the concrete cylinder 503 and the hopper 901.

[0081] (5) Turn on the hydraulic station and adjust the overflow valve 104 to set the maximum value P of the hydraulic oil pressure; control the throttle solenoid valve 102 to allow the hydraulic oil to be injected into the rear of the oil cylinder 501 from the oil filling port 511, pushing the oil cylinder piston 504 forward to the initial position. At this time, the concrete piston 507 is located at the suction port 509 of the concrete cylinder 503.

[0082] (6) Seal the concrete cylinder with the cylinder cover 6 and the sealing gasket 7 to prevent the concrete material from entering the concrete cylinder in advance.

[0083] (7) Concrete material is loaded into the hopper 901. The loading amount must ensure that after the suction is completed, the lowest position of the concrete material is still higher than the highest point of the hopper opening 902, so as to ensure that the suction material is sufficient; in addition, the loading amount must be the same under different water-cement ratios to eliminate experimental errors as much as possible.

[0084] 2.1 Natural suction material filling rate test method

[0085] (1) The control system adjusts the throttle solenoid valve 102 and the displacement sensor 2 to set the required stroke of the oil cylinder piston 504, that is, the suction stroke of the concrete cylinder 503, and calculates the theoretical maximum filling rate of the concrete cylinder based on the set stroke, that is, the volume V0 of the concrete cylinder that can theoretically be filled without the presence of large-sized air.

[0086] (2) After the loading is completed, the cylinder cover 6 and the sealing gasket 7 of the sealed concrete cylinder 503 are opened.

[0087] (3) Turn on the data acquisition system of the displacement sensor 2 and the hydraulic pressure sensor 3 to monitor the displacement changes of the cylinder piston 504 and the pressure changes of the hydraulic oil during the experiment.

[0088] (4) Turn on the high-speed camera 10 to monitor the concrete cylinder 503's suction process and the changing states of the concrete material and internal bubbles in the concrete cylinder 503.

[0089] (5) Control the throttle solenoid valve 102 to allow the hydraulic oil to be injected into the front of the oil cylinder 501 from the oil filling port 510, start to absorb the material, and gradually push the oil cylinder piston 504 back to the predetermined stroke position.

[0090] (6) After the suction is completed, the concrete cylinder 503 is sealed using the cylinder cover 6 and the sealing gasket 7, and then the hopper and its movable bracket 9 are removed.

[0091] (7) Place the measuring cylinder 8 below the suction port 509 of the concrete cylinder 503.

[0092] (8) Open the cylinder cover 6 and the sealing gasket 7 for sealing the concrete cylinder 503.

[0093] (9) Turn on the high-speed camera 10 to monitor the changing state of the concrete material and the internal bubbles in the concrete cylinder 503 during the pumping process, the falling state of the concrete material during the process of being pumped from the concrete cylinder 503 to the measuring cylinder 8, and the volume change of the pumped concrete material.

[0094] (10) Control the throttle solenoid valve 102 to allow hydraulic oil to be injected into the rear of the oil cylinder 501 from the oil filling port 511, and gradually pump out the concrete sucked into the concrete cylinder 503 until the concrete material is completely pumped out and the concrete piston 507 moves to the position of the suction port 509.

[0095] (11) Turn on the vibration table 11 and fully vibrate the concrete pumped into the measuring cylinder 8 until it reaches a volume V1 without the presence of large-sized air.

[0096] (12) Calculate the natural suction filling rate of the concrete cylinder under the natural suction method under the same piston stroke and the same rheological properties of concrete:

[0097] (13) The concrete cylinder 503 of different cylinder diameters can be replaced, the overflow valve 104 can be adjusted to set different hydraulic oil pressures, the stroke of the cylinder piston 504 can be adjusted, and concrete with different characteristics can be used to carry out natural suction filling rate tests of the concrete cylinder under different conditions.

[0098] (14) By comparing the displacement of the cylinder piston 504 monitored by the displacement sensor 2 during the suction and pumping process, the hydraulic oil pressure change monitored by the hydraulic sensor 3, and the state and volume of concrete suction and pumping recorded by the high-speed camera 10, the distribution position of the air sucked into the concrete cylinder is analyzed, and the air mixing pattern during the suction process is obtained.

[0099] (15) Combine (14) with the filling rate calculated in (12) to analyze the changing characteristics of the natural suction filling rate of the concrete cylinder and analyze its influence law.

[0100] 2.2 Pressure filling rate test method

[0101] (1) The control system adjusts the throttle solenoid valve 102 and the displacement sensor 2 to set the stroke of the oil cylinder piston 504 to be used, that is, the theoretical maximum stroke (L0) of the concrete cylinder 503.

[0102] (2) After the loading is completed, the cylinder cover 6 and the sealing gasket 7 of the sealed concrete cylinder 503 are opened.

[0103] (3) Turn on the data acquisition system of the displacement sensor 2 and the hydraulic pressure sensor 3 to monitor the displacement changes of the cylinder piston 504 and the pressure changes of the hydraulic oil during the experiment.

[0104] (4) Control the throttle solenoid valve 102 to allow the hydraulic oil to be injected into the front of the oil cylinder 501 from the oil filling port 510, start to absorb the material, and gradually push the oil cylinder piston 504 back to the predetermined stroke position.

[0105] (5) After the suction is completed, the concrete cylinder 503 is closed using the cylinder cover 6 and the sealing gasket 7, and then the hopper and its movable bracket 9 are removed.

[0106] (6) Control the throttle solenoid valve 102 to allow hydraulic oil to be injected into the rear of the oil cylinder 501 from the oil filling port 511, start to absorb material, and gradually push the oil cylinder piston 504 forward, so that the concrete piston 507 pushes the concrete forward.

[0107] (7) When the hydraulic oil pressure detected by the hydraulic sensor 3 reaches the maximum value P of the hydraulic station oil supply pressure, the concrete piston 507 starts to push the concrete forward until the pressure transmitter test value is P. The distance moved forward is ΔL, and the throttling solenoid valve 102 is controlled to stop injecting oil.

[0108] (8) Place the measuring cylinder 8 below the suction port 509 of the concrete cylinder 503.

[0109] (9) Open the cylinder cover 6 and the sealing gasket 7 for sealing the concrete cylinder 503.

[0110] (10) Turn on the high-speed camera 10 to monitor the changing state of the concrete material and the internal bubbles in the concrete cylinder 503 during the pumping process, as well as the falling state of the concrete material during the process of being pumped from the concrete cylinder 503 to the measuring cylinder 8 and the volume change of the pumped concrete material.

[0111] (11) Control the throttle solenoid valve 102 to allow hydraulic oil to be injected into the rear of the oil cylinder 501 from the oil filling port 511, gradually pumping out the concrete sucked into the concrete cylinder 503 until the concrete material is completely pumped out and the concrete piston 507 moves to the position of the suction port 509.

[0112] (12) Calculate the pressure filling rate of concrete under natural suction mode at different pressures P for concrete with the same piston stroke and the same rheological properties:

[0113] (13) The concrete cylinder 503 of different cylinder diameters can be replaced, the overflow valve 104 can be adjusted to set different hydraulic oil pressures, the stroke of the cylinder piston 504 can be adjusted, and concrete with different characteristics can be used to carry out natural suction filling rate tests of the concrete cylinder under different conditions.

[0114] (14) By comparing the displacement of the cylinder piston 504 monitored by the displacement sensor 2 during the suction and pumping process, the hydraulic oil pressure change monitored by the hydraulic sensor 3, and the state and volume of concrete suction and pumping recorded by the high-speed camera 10, the distribution position of the air sucked into the concrete cylinder is analyzed, and the air mixing pattern during the suction process is obtained.

[0115] (15) Combine (14) with the pressure filling rate calculated in (12) to analyze the changing characteristics of the concrete cylinder pressure filling rate and analyze its influence law.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for testing the filling rate of a concrete pump delivery cylinder, characterized in that: The test was conducted using a concrete pump cylinder filling rate test platform, which included a hydraulic station, a control system, a concrete suction device, a cylinder cover, a sealing gasket, a hopper, and a movable bracket. The concrete suction device includes an oil cylinder, a water washing tank, a concrete cylinder, an oil cylinder piston, a piston rod, a connecting shaft, a concrete piston, and a fixed base; the oil cylinder and the concrete cylinder are connected via a water washing tank, and the water washing tank and the concrete cylinder are conductive and can be used to clean the concrete cylinder after testing; the piston rod is slidably arranged in the oil cylinder through the oil cylinder piston, and the concrete piston is slidably arranged in the concrete cylinder; one end of the connecting shaft passes through the water washing tank and is connected to the concrete piston, and the other end is connected to the piston rod; The oil cylinder is connected to the hydraulic station through an oil pipe. A displacement sensor and a hydraulic pressure sensor are provided on the oil cylinder. Both the displacement sensor and the hydraulic pressure sensor are connected to the control system to obtain the displacement and hydraulic pressure information of the piston rod in the oil cylinder and control the movement of the piston rod; The concrete cylinder is provided with a suction port at one end away from the oil cylinder, and a detachable cylinder cover is provided on the suction port, and the cylinder cover seals the suction port with a sealing gasket; the hopper is provided on a movable bracket, and the hopper is used to hold concrete. The hopper is provided with a hopper opening, and the hopper opening can be docked with the suction port by moving the movable bracket; The control system controls the piston rod to drive the concrete piston to move, thereby achieving the suction and pumping of materials in the concrete cylinder; The experimental platform also includes a measuring cylinder and a vibration table. The measuring cylinder is used to receive the concrete pumped out of the concrete cylinder, and the vibration table is used to vibrate and expel the air from the concrete in the measuring cylinder. The experimental platform also includes a high-speed camera for recording the suction and pumping process; the hydraulic station includes an oil pump, a throttle solenoid valve, an oil tank, a relief valve, and a pressure gauge; the oil pump on the oil tank is connected to the oil cylinder via an oil pipe, and the throttle solenoid valve controls the forward and backward movement of the oil cylinder piston in the oil cylinder, which in turn drives the concrete piston in the concrete cylinder via a connecting shaft to achieve concrete suction and pumping; This method includes pre-experimental preparation and requirements, natural inhalation filling rate test method and pressure filling rate test method, among which: Pre-experimental preparation and requirements include the following steps: (1) Select the concrete cylinder material according to the experiment type. Transparent material is used for natural filling rate test, and steel material is used for pressure filling rate test. (2) Determine the diameter of the concrete cylinder and select a matching concrete piston; (3) Connect the concrete cylinder and the water washing tank, connect the concrete piston to the connecting shaft, and assemble the experimental platform; (4) Extend the suction port completely into the hopper opening to fully wet the concrete cylinder and hopper; (5) Turn on the hydraulic station, adjust the overflow valve to set the maximum hydraulic oil pressure P, control the throttle solenoid valve to allow the hydraulic oil to be injected into the rear of the cylinder, and push the cylinder piston forward to the initial position. At this time, the concrete piston is at the suction port position; (6) Seal the concrete cylinder with a cylinder cover and a gasket to prevent the concrete from entering the cylinder prematurely; (7) Load concrete into the hopper in an amount that ensures the lowest point of the concrete after suction is higher than the highest point of the hopper opening, and the loading amount is the same for different water-cement ratios; The natural inhalation fill rate test method includes the following steps: (1) The control system adjusts the throttle solenoid valve and displacement sensor to set the stroke of the cylinder piston and calculate the theoretical maximum filling volume V0 of the concrete cylinder; (2) After loading is completed, open the cylinder cover and gasket; (3) Turn on the data acquisition system of the displacement sensor and hydraulic sensor to monitor the displacement changes of the cylinder piston and the hydraulic oil pressure changes; (4) Turn on the high-speed camera to monitor the concrete cylinder's suction process, concrete state, and bubble changes during the suction process; (5) Control the throttle solenoid valve to inject hydraulic oil into the front of the cylinder, push the cylinder piston back to the predetermined stroke position, and complete the material suction; (6) After the suction is completed, close the concrete cylinder with the cylinder cover and gasket, and then remove the hopper; (7) Place the measuring cylinder under the suction port; (8) Open the cylinder head and gasket; (9) Turn on the high-speed camera to monitor the changes of concrete and bubbles in the concrete cylinder during the pumping process, as well as the state and volume changes of the concrete pumped into the measuring cylinder; (10) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, and pump the concrete out of the concrete cylinder until the concrete piston moves to the suction port position; the pumping process is monitored by a high-speed camera to monitor the changes in the concrete and bubbles in the concrete cylinder and the state and volume changes of the concrete pumped into the measuring cylinder; (11) Start the vibrating table and fully vibrate the concrete pumped into the measuring cylinder until the volume V1 is reached without the presence of large-scale air; (12) Calculate the natural suction filling rate of the concrete cylinder under the natural suction mode under the same piston stroke and the same rheological properties of concrete ; The pressure fill rate test method includes the following steps: (1) The theoretical maximum stroke L0 of the cylinder piston is set by adjusting the throttle solenoid valve and displacement sensor through the control system; (2) After loading is completed, open the cylinder cover and gasket; (3) Turn on the data acquisition system of the displacement sensor and hydraulic sensor to monitor the displacement changes of the cylinder piston and the hydraulic oil pressure changes; (4) Control the throttle solenoid valve to inject hydraulic oil into the front of the cylinder, push the cylinder piston back to the predetermined stroke position, and complete the material suction; (5) After the suction is completed, close the concrete cylinder with the cylinder cover and gasket and remove the hopper; (6) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, pushing the cylinder piston forward. When the hydraulic sensor detects that the pressure reaches the maximum value P, the forward distance is recorded as ΔL, and the oil injection is stopped; (7) Place the measuring cylinder under the suction port; (8) Open the cylinder head and gasket; (9) Turn on the high-speed camera and monitor the changing state of the concrete material and the internal bubbles in the concrete cylinder during the pumping process, the falling state of the concrete material during the process of being pumped from the concrete cylinder to the measuring cylinder, and the volume change of the pumped concrete material; (10) Control the throttle solenoid valve to inject hydraulic oil into the rear of the cylinder, gradually pumping out the concrete sucked into the concrete cylinder until the concrete is completely pumped out and the concrete piston moves to the suction port position; (11) Calculate the pressure filling rate of concrete under natural suction mode with the same piston stroke and the same rheological properties at different pressures P .

2. The testing method according to claim 1, wherein: In the pressure filling rate test, different hydraulic oil pressures P are set by adjusting the relief valve, and the filling rate changes under different pressures are recorded.

3. The testing method according to claim 1, wherein: By replacing concrete cylinders with different cylinder diameters and concrete with different rheological properties, the test was repeated to analyze the changing pattern of the filling rate.

4. The testing method according to claim 1, wherein: By comparing the monitoring data of the displacement sensor and hydraulic sensor with the records of the high-speed camera, the air mixing pattern during the suction process and its influence on the filling rate are analyzed.

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