High-precision concrete liquid penetration test integrated system and use method thereof

Abstract

The invention discloses a high-precision concrete liquid penetration test integrated system and a use method. The system comprises a closed liquid containing box, a self-absorption turbine, a tank body, an upstream high-precision flow meter, a downstream high-precision flow meter, a data acquisition port set, a downstream data acquisition port set, a liquid pressure detector, a digital display differential pressure sensor, a concrete permeation device and a multi-channel recorder. The system can comprehensively collect the flow velocity, the surface pressure and the up-down pressure difference before and after the liquid flows through the concrete test piece, and synchronously display real-time data to computer software. Synchronous data acquisition ensures the accuracy of test data under different boundary conditions, and the system provided by the invention can accurately measure the permeability of concrete test pieces with different shapes and different fracture states under different pressures on the premise of not influencing the structural integrity of the test pieces.

Description

Technical Field

[0001] The invention relates to the field of liquid penetration ability evaluation of different concrete materials, and in particular to a high-precision concrete liquid penetration test integrated system and a use method. Background Art

[0002] Functional concrete materials have been widely used in the construction field due to their excellent mechanical properties. However, due to their internal porous structure and easy cracking characteristics, their permeability and transport performance has become a matter of great concern. In order to better understand the connected paths in the internal structure of concrete, it is crucial to reasonably and effectively evaluate its permeability, which is directly related to the durability prediction of concrete and the material transport performance of functional concrete. In particular, the existence of connected paths will increase the risk of intrusion of harmful substances, leading to steel corrosion and changes in the internal microstructure, ultimately affecting the service life of structural concrete. In the permeability test, the connected paths inside the concrete affect both the viscosity and inertial dissipation capacity of the fluid, thereby affecting the material transport efficiency. Therefore, accurately measuring the viscous permeability and inertial permeability of concrete is crucial to quantify its related performance, which not only provides reliable data support for the full life cycle prediction of concrete, but also lays a quantitative parameter foundation for the material design of functional concrete.

[0003] The HS concrete permeameter in the Concrete Impermeability Tester (JG / T 249-2009) mentioned in the Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete (GB / T 50082-2009) is widely used to determine the penetration depth and penetration grade of uncracked ordinary concrete. However, this test method has limitations and cannot directly measure the permeability coefficient of concrete. This is because the boundary parameters of concrete water penetration are difficult to determine during the test, and the water flux cannot be directly evaluated. In addition, the test also requires splitting measurements of concrete specimens, which is a cumbersome process and has limited evaluation accuracy, making it difficult to apply to the evaluation of various concrete transmission properties. Many authoritative journal articles point out that when liquid flows through the connected voids or cracks inside concrete, there is significant nonlinear flow behavior. Studies have shown that in actual engineering, it is crucial to reasonably evaluate the material transmission properties of concrete and accurately determine its inherent permeability for the mix design of permeable concrete and the evaluation of the durability of cracked or uncracked structural concrete. In addition, it is also necessary to test the transmission rate under multiple pressure gradients. The permeability coefficient measuring instrument recommended in the current "Permeable Concrete Test Method" (T / CSTM 00040-2019), or the permeability coefficient testing device provided in patents CN109142183A and CN110618069A, all adopt a test method under a certain liquid level, that is, calculating the time required for a specific amount of water to pass through the permeable concrete specimen. However, these devices and methods have some shortcomings: 1. Single pressure gradient measurement: The current test method relies on Darcy's law and only measures the flow rate under a single pressure gradient. It is difficult to observe the nonlinear behavior of the fluid or analyze the geometric characteristics of the internal connection path of the concrete by changing the pressure gradient. This limits the comprehensive understanding of the complex permeability path and the permeability behavior of concrete under different working conditions. 2. Inaccurate pressure measurement: The pressure obtained during the test is the pressure on the upper surface of the specimen, not the effective pressure gradient, resulting in the test results cannot fully reflect the actual transmission of the fluid in the specimen. 3. The complexity of channel connection and the inaccurate boundary parameters: The channel connection between the upper and lower liquid surfaces of the specimen is complex, and the sensor of the test device is difficult to effectively measure the pressure changes of the upper and lower liquid surfaces. When the liquid flows through these complex channels, the pressure loss generated cannot be accurately recorded, resulting in a smaller test result for the permeability coefficient. 4. Single test conditions: The existing test system is only applicable to specific conditions and is difficult to adapt to concrete specimens under different working conditions, especially specimens of different sizes, shapes and types. This makes the test system limited when dealing with complex and changing actual working conditions.

[0004] In a device for measuring the permeability coefficient of high permeability concrete with announcement number CN114923833B, a gravity sensor and an open exposure data acquisition method are used to measure the water flux per unit time under different pressure gradients by changing the water pressure. However, the device still has the following shortcomings: 1. Data acquisition is discontinuous, the cumulative observation efficiency is low, and there is a lack of observation of fluid temperature. The device measures the flow rate by weight method, and it is necessary to accumulate and observe the flow rate within a specific time period, resulting in low test efficiency. In addition, the pressure control is only near a certain gradient, and the test liquid temperature is not effectively monitored, which makes it difficult to achieve a more accurate evaluation of fluid transmission behavior, and there are errors in the observed data. 2. The scope of application of the test sample is limited. Due to the limited pressure adjustment range, the device is mainly suitable for high permeability concrete specimens, such as cracked concrete or permeable concrete. It has limitations when testing uncracked ordinary concrete and cannot effectively measure its permeability. 3. The fluid circulation is not closed, and there are safety hazards. The device adopts an open test method and cannot achieve fluid circulation in a closed pipeline. This design is prone to liquid splashing, especially toxic liquids, which may cause environmental pollution and operational safety issues. 4. Separate data collection increases the complexity of analysis. The pressure gradient and water flow rate are collected separately, lacking simultaneous data, resulting in high data integration and analysis costs. In addition, the time cost of collecting and analyzing data increases, affecting the convenience of the test process. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the multiple limitations existing in the existing penetration testing technology in the prior art, namely, the inability to accurately measure fluid transmission behavior under a variety of pressure gradients, the cumbersome operation steps and the lack of suitability for boundary condition control under complex working conditions, the difficulty in keeping data acquisition and analysis synchronized, and other defects, and to provide a high-precision concrete liquid penetration test integrated system and a method of use.

[0006] The technical solution adopted by the present invention to solve its technical problem is a high-precision concrete liquid penetration test integrated system, including a closed liquid holding box, a self-priming turbine, a tank, an upstream high-precision flow meter, a downstream high-precision flow meter, a data acquisition port set, a downstream data acquisition port set, a liquid pressure detector, a digital display differential pressure sensor, a concrete penetration device, and a multi-channel recorder;

[0007] The self-priming turbine is connected to the closed liquid holding box through a conduit, the closed liquid holding box is connected to the tank body through a conduit, an air compressor and a fine-tuning pressure ball valve are provided on the tank body, and the tank body is connected to an upstream high-precision flow meter through the fine-tuning pressure ball valve;

[0008] The upstream high-precision flow meter is connected to the data acquisition port set through a conduit, the data acquisition port set is provided with no less than four ports, and is respectively connected to a liquid pressure detector, a digital display differential pressure sensor, and a concrete penetration device through conduits, while the concrete penetration device is connected to the downstream data acquisition port set;

[0009] The downstream data acquisition port set is provided with no less than three ports, and is connected to the digital differential pressure sensor and the downstream high-precision flow meter through a conduit, and the downstream high-precision flow meter flows back to the closed liquid holding tank through the conduit;

[0010] The upstream high-precision flow meter, the downstream high-precision flow meter, the liquid pressure detector, and the digital differential pressure sensor are all connected to the multi-channel recorder through lines, and the multi-channel recorder is connected to the computer terminal through lines.

[0011] Furthermore, the sealed liquid holding box has no less than four connection ports, which are respectively connected to an outflow pipe, a pumping and filling pipe, a reflux pipe, and a temperature measuring instrument.

[0012] Furthermore, the self-priming turbine has a suction end and an output end, the outflow pipe is connected to the suction end, and the self-priming turbine generates pumping pressure on the liquid and pumps it from the output end to the tank.

[0013] Furthermore, the tank body has no less than three connection ports, which are respectively connected to an air compressor, a pumping pipe, and a check pipe. A third one-way check valve is provided on the check pipe. The other end of the third one-way check valve is connected to an intermediate pipe, and the other end of the intermediate pipe is connected to a fine-tuning pressure ball valve.

[0014] Furthermore, the conduits are all made of high-pressure resistant materials, and the joint parts are all connected by high-pressure resistant threaded sealing.

[0015] Furthermore, the concrete penetration device includes a penetration box, a liquid inlet pipe, a liquid outlet pipe, and a liquid collection container. The liquid inlet and the liquid outlet are both provided with liquid separation channels, and the liquid separation channels are both connected to ball valves, and the ball valves are connected to the liquid collection container through conduits; the liquid inlet and the liquid outlet are relatively arranged on both sides of the penetration box.

[0016] Furthermore, a concrete specimen is sealed in the penetration box, a side of the concrete specimen is sealed with adhesive tape, and a gap between the penetration box and the concrete specimen is filled with liquid sealant.

[0017] The present invention further solves the technical problem by adopting a technical solution that is a method for using a high-precision concrete liquid penetration test integrated system, comprising the following steps:

[0018] S1. The concrete specimen is subjected to vacuum saturation treatment for 1 to 2 hours to reduce the time to reach a stable state, wherein the treatment area includes the crack area of ​​cracked concrete or the hydraulic exposure area of ​​permeable concrete / porous ordinary concrete;

[0019] S2. Before installing the concrete specimen, there is no restriction on the geometric shape of the specimen cross section, but it is necessary to ensure that the shape of the specimen cross section is consistent in the direction of liquid flow or the height direction of the specimen, and ensure that there is no lateral leakage in the communication path between the upper pressure surface and the lower pressure surface of the specimen; by using tape to perform preliminary sealing on the side and upper and lower end surfaces of the concrete specimen, the concrete specimen is placed in the penetration box, and the gap between the penetration box and the specimen is filled with liquid sealant. After the sealant is dry, the tape on the upper and lower pressure surfaces is cut off to expose the test area;

[0020] S3, installing the sealed concrete specimen into the concrete penetration device, and installing the device into the high-precision concrete liquid penetration test integrated system;

[0021] S4. Check the liquid level of the sealed liquid holding box to ensure that the liquid level is between 2 / 3 and 4 / 5 of the total height of the box, and place the probe of the temperature detector at 1 / 3 to 2 / 3 between the liquid level and the bottom of the box;

[0022] S5. Test run the equipment, set the pressure value of the self-priming turbine to 0.01 to 1 MPa, open the fine-tuning pressure ball valve, check that the wiring is in good contact, confirm that the data collected by the upstream and downstream high-precision flow meters, liquid pressure detectors, and digital differential pressure sensors can be recorded and displayed by the multi-channel recorder and displayed on the computer, and check all catheter interfaces to ensure that they are leak-proof and well sealed;

[0023] S6. Gradually increase the pressure value of the self-priming turbine to ensure that the pressure of the liquid pressure detector is lower than the compressive strength of the concrete specimen. When the flow rate reaches 80% of the upstream high-precision flow meter range or 80% of the digital differential pressure sensor range, stop pressurizing; if the pressure is not enough, pressurize through the conduit and the air compressor; test to maintain this flow state, observe the bubbles in the liquid collection container, close the ball valve to effectively remove the gas in the system, until the flow rate difference does not exceed 7% of the reading, it is considered that the turbulent state has been reached; for denser specimens, the ball valve can be selectively opened to speed up the time it takes for the liquid to fill the entire system;

[0024] S7. When the liquid fills the entire test system, start formal testing and data collection; adjust the pressure value of the self-priming turbine so that the reading of the digital differential pressure sensor or the flow rate reading of the downstream high-precision flow meter reaches the minimum; turn on the temperature measuring instrument to record the temperature of the test liquid, and gradually increase the pressure of the liquid pump system so that the collection reading reaches 80% of the range; record the collection results, which are continuous pressure gradients {ΔP│ΔP1, ΔP2, ΔP3, ..., ΔPn} and flow rates {Q│Q1, Q2, Q3, ..., Qn}, where the data has isochronous properties;

[0025] S8. Query the fluid physical property data according to the liquid temperature value to confirm the viscosity and density of the liquid at this temperature; import the collected data {ΔP│ΔP1, ΔP2, ΔP3, ..., ΔPn} and {Q│Q1, Q2, Q3, ..., Qn} into the calculation, and use the formula to calculate the linear coefficient A and the nonlinear coefficient B, and then import the results into the formula to calculate the inherent permeability coefficient K v and inertial permeability coefficient K i .

[0026] Further, the calculation formula in step S8 is:

[0027]

[0028] The linear coefficient A and nonlinear coefficient B are calculated and substituted into formulas (2) and (3) to calculate the inherent permeability coefficient K. v and inertial permeability coefficient K i :

[0029]

[0030]

[0031] In summary, the present invention has the following beneficial technical effects:

[0032] 1. The sealed closed-loop liquid seepage test helps prevent liquid splashing, contamination, and even safety hazards; 2. Digital control of pressure gradient and upper surface pressure detection reduces pressure fluctuations, and can more accurately test the boundary parameters required for the permeability coefficient of concrete. At the same time, it can also monitor the liquid pressure to prevent excessive hydraulic pressure on the upper surface of the concrete from causing changes or even damage to the void structure; 3. Adopt upstream and downstream high-precision flow meters to monitor the volume of liquid flowing in and out, observe the capillary suction volume of the liquid in real time, judge the saturated flow stage when the liquid passes through the test concrete, and measure the time required for it to reach this stage; 4. Isochronous and real-time observations are carried out on each boundary parameter to reduce the measurement errors caused by various human factors during manual testing, and it has the function of coarse and fine adjustment of the pressure gradient of the control specimen; 5. It has strong mobility and operability, is suitable for concrete specimens under different working conditions, can provide accurate evaluation tests, and provide hardware and test method support for the connectivity of concrete voids, durability evaluation during service, and quantification of transmission performance of mix design of permeable concrete; 6. This design is conducive to the integration and intelligent automation of concrete material penetration testing, and provides theoretical support for the production of precision instruments in laboratories. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of an embodiment of a high-precision concrete liquid penetration test integrated system of the present invention;

[0034] Figure 2 It is a structural schematic diagram of a concrete penetration device of an embodiment of a high-precision concrete liquid penetration test integrated system of the present invention;

[0035] Figure 3 It is a schematic diagram of a specimen sealing seam in an embodiment of a high-precision concrete liquid penetration test integrated system of the present invention.

[0036] Description of reference numerals:

[0037] 100, closed liquid container; 101, outflow port; 102, reflux port; 103, pumping port; 110, outflow pipe; 111, pumping pipe; 112, reflux pipe; 120, temperature measuring instrument; 121, probe; 130, box filter; 200, self-priming turbine; 201, suction end; 202, output end; 203, digital display; 204, pressure control button; 300, tank; 301, boost port; 302, pumping port; 303, check port; 310, inlet pipe ; 311, first one-way check valve; 312, pump inlet pipe; 320, connecting conduit; 321, second one-way check valve; 322, air inlet pipe; 323, air compressor; 330, check pipe; 331, third one-way check valve; 332, intermediate pipe; 340, fine-tuning pressure ball valve; 400, upstream high-precision flowmeter; 401, inlet conduit; 402, outlet conduit; 410, downstream high-precision flowmeter; 411, downstream flowmeter conduit; 500, data acquisition port set; 501, flowmeter port; 502, upstream differential pressure port; 503, penetration port; 504, pressure detection port; 510, downstream data acquisition port set; 511, filter port; 512, downstream differential pressure port; 513, downstream flow meter port; 520, intermediate filter; 521, filter inlet conduit; 522, filter outlet conduit; 600, liquid pressure detector; 700, digital differential pressure sensor; 701, high pressure area conduit; 702, low pressure area conduit; 800, concrete penetration device; 801, penetration inlet Catheter; 810, penetration box; 811, liquid sealant; 812, liquid inlet pipe; 813, liquid outlet pipe; 814, inlet liquid separation channel; 815, outlet liquid separation channel; 816, tape; 820, concrete specimen; 830, liquid collection container; 831, toxic gas filter; 840, inlet duct; 841, first ball valve; 842, upstream duct; 843, downstream duct; 844, second ball valve; 845, outlet duct; 900, multi-channel recorder; 910, computer terminal. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0039] Reference Figure 1 This embodiment includes a closed liquid holding box 100, a self-priming turbine 200, a tank body 300, an upstream high-precision flow meter 400, a downstream high-precision flow meter 410, a data acquisition port set 500, a downstream data acquisition port set 510, a liquid pressure detector 600, a digital display differential pressure sensor 700, a concrete penetration device 800, and a multi-channel recorder 900.

[0040] The sealed liquid holding box 100 is made of a high-strength corrosion-resistant material with good sealing performance and is used to store the test liquid. The sealed liquid holding box 100 is provided with four connection ports, namely an outflow port 101, a reflux port 102, a pumping and filling port 103 and a port for temperature measurement. The outflow port 101 is connected to an outflow pipe 110, the reflux port 102 is connected to a reflux pipe 112, and the pumping and filling port 103 is connected to a pumping and filling pipe 111, through which the liquid can be taken out and filled. A temperature measuring instrument 120 is provided on the temperature measurement port, and a probe 121 is provided at the bottom of the temperature measuring instrument 120, so that the liquid temperature can be displayed in real time through the temperature measuring instrument 120. In addition, a high-mesh, low-aperture box filter 130 is installed at one end of the outflow pipe 110 located inside the sealed liquid holding box 100 to ensure the purity and safety of the liquid in the entire system. In this embodiment, the liquid level of the sealed liquid holding box 100 should be located at 2 / 3 to 4 / 5 of the total height of the box, the probe 121 should be placed at 1 / 3 to 2 / 3 between the liquid level and the bottom of the box, and the bottom of the reflux pipe 112 should be higher than the top of the liquid level.

[0041] The self-priming turbine 200 has two ports, a suction end 201 and an output end 202, and also has a digital display 203 and a pressure control button 204. The liquid enters the suction end 201 of the self-priming turbine 200 through the outflow pipe 110 of the closed liquid holding box 100, that is, the outflow pipe 110 is connected to the suction end 201. The self-priming turbine 200 generates pumping pressure for the liquid, and cooperates with the digital display 203 and the switch and pressure control button 204 to adjust the pressure of the system. In addition, the self-priming turbine 200 is built with an intelligent pressure control module, which has the functions of silent, self-priming, variable frequency and constant pressure pumping liquid to ensure that the safety and stability of the system are effectively guaranteed during the long-term seepage test.

[0042] The tank body 300 is a high-pressure resistant steel tank body 300, and has three ports, namely a boost port 301, a pumping port 302 and a check port 303. The boost port 301 is connected with a connecting conduit 320, a second one-way check valve 321, an air inlet pipe 322 and an air compressor 323 in sequence, and the compressed air inlet pipe 322 and the air compressor 323 are further pressurized to ensure the stability of the liquid pressure in the system. The pumping port 302 is connected with an inlet pipe 310, a first one-way check valve 311 and a pumping pipe 312 in sequence. The check port 303 is connected with a check pipe 330, a third one-way check valve 331, an intermediate pipe 332 and a fine-tuning pressure ball valve 340 in sequence. Driven by sufficient pressure, the liquid enters the third one-way check valve 331 from the check pipe 330 and flows to the fine-tuning pressure ball valve 340 to adjust the flow rate and pressure of the liquid.

[0043] The regulated liquid enters the upstream high-precision flowmeter 400 through the inflow conduit 401 on the left side of the upstream high-precision flowmeter 400, and after being measured, enters the data acquisition port set 500 through the outflow conduit 402. In addition, the upstream high-precision flowmeter 400 and the downstream high-precision flowmeter 410 are two flowmeters with exactly the same properties. The type of flowmeter can be selected according to the test conditions and is not limited to a specific type. Applicable flowmeter types include but are not limited to mass flowmeters, volume flowmeters, differential pressure flowmeters, float flowmeters, turbine flowmeters, electromagnetic flowmeters, vortex flowmeters, and ultrasonic flowmeters.

[0044] The data acquisition port set 500 has four ports, namely a flow meter port 501, an upstream pressure difference port 502, a penetration port 503, and a pressure detection port 504. The flow meter port 501 is connected to the outflow conduit 402, the upstream pressure difference port 502 is connected to the digital pressure difference sensor 700, the penetration port 503 is connected to the concrete penetration device 800 through the penetration inlet conduit 801, and the pressure detection port 504 is connected to the liquid pressure detector 600.

[0045] The downstream data acquisition port set 510 has three ports, namely, a filter port 511, a downstream pressure difference port 512, and a downstream flow meter port 513. The filter port 511 is connected to the output side of the concrete penetration device 800, and an intermediate filter 520 is arranged between the filter port 511 and the concrete penetration device 800. The liquid enters the intermediate filter 520 through the filter inflow conduit 521, and then flows out of the filter outflow conduit 522 to the filter port 511. The downstream pressure difference port 512 is connected to the digital pressure difference sensor 700. Specifically, the upstream pressure difference port 502 is connected to the left side of the digital pressure difference sensor 700 through the high-pressure area conduit 701, and the downstream pressure difference port 512 is connected to the right side of the digital pressure difference sensor 700 through the low-pressure area conduit 702. The downstream flow meter port 513 is connected to the downstream high-precision flow meter 410 through the downstream flow meter conduit 411. After the measurement is completed, the liquid flows back to the closed liquid holding box 100 through the reflux pipe 112 to ensure the circulation of the liquid in the system.

[0046] Reference Figure 2 and Figure 3The concrete penetration device 800 is suitable for measuring the permeability of concrete specimens 820 of various shapes under different load environment conditions, such as cracked specimens, cracked specimens under load, or permeable concrete specimens 820 of different shapes. The system can safely and efficiently perform permeability measurements. The concrete infiltration device 800 includes a penetration box 810, a liquid inlet pipe 812, a liquid outlet pipe 813, and a liquid collecting container 830. The liquid inlet pipe 812 has an inlet liquid separation channel 814, and the liquid outlet pipe 813 has an outlet liquid separation channel 815. The inlet liquid separation channel 814 is connected to a first ball valve 841 through an inlet conduit 840, and the outlet liquid separation channel 815 is connected to a second ball valve 844 through an outlet conduit 845. At the same time, the first ball valve 841 is connected to the left side of the liquid collecting container 830 through an upstream conduit 842, and the second ball valve 844 is connected to the right side of the liquid collecting container 830 through a downstream conduit 843. A toxic gas filter 831 is also arranged above the liquid collecting container 830. The liquid can selectively flow into the diversion liquid collecting container 830 through the inlet liquid separation channel 814, and the air in the system is removed through the toxic gas filter 831. A concrete specimen 820 is sealed in the penetration box 810 . The side of the concrete specimen 820 is sealed with a tape 816 , and a gap between the penetration box 810 and the concrete specimen 820 is filled with a liquid sealant 811 .

[0047] The multi-channel recorder 900 is connected to the upstream high-precision flow meter 400, the downstream high-precision flow meter 410, the liquid pressure detector 600, and the digital differential pressure sensor 700 through lines. During the test process, the test data are recorded in the multi-channel recorder 900 and digitally displayed through the computer.

[0048] In this embodiment, all conduits are made of high-pressure resistant materials, and the joints or port parts are connected by high-pressure resistant threaded seals. High-pressure resistant materials may include but are not limited to hard corrosion-resistant metal materials or soft metal wire braided rubber tubes to ensure the reliability and sealing of the system under high-pressure environments.

[0049] The present invention uses a method for using a high-precision concrete liquid penetration test integrated system, comprising the following steps:

[0050] Step 1: Before testing, for concrete specimen 820 (such as cracked concrete, permeable concrete or porous ordinary concrete), the test area of ​​the specimen should preferably be subjected to vacuum saturation treatment for 1 to 2 hours to reduce the time to reach a stable state. The specific area is: the crack part of cracked concrete, the hydraulic exposure area of ​​permeable concrete or porous ordinary concrete.

[0051] Step 2: When installing the concrete specimen 820, the test method does not limit the geometric shape of the specimen cross section, so the design of the penetration box 810 has high flexibility. However, it should be noted that the shape of the specimen cross section should be consistent in the liquid flow direction or height direction, and the communication path between the upper and lower pressure surfaces of the specimen should not have lateral leakage. Therefore, the upper and lower pressure surfaces must be sealed with the penetration box 810 to form an independent sealed chamber. The distance between the upper and lower pressure surfaces of the specimen is L, and the effective penetration area is AS. The method is: encapsulate the tape 816 on the side of the specimen, and cover the upper and lower end surface penetration area of ​​the specimen with the tape 816. Put the initially encapsulated specimen into the penetration box 810, and fill the gap between the penetration box 810 and the specimen with liquid sealant 811. It is recommended to use a polymer sealing material that is elastic after drying. After the sealant is completely cured and forms strength, carefully remove the tape 816 on the upper and lower pressure surfaces to ensure that the test area is completely exposed.

[0052] Step 3: When preparing for the test, install the concrete specimen 820 into the system and ensure that the equipment is started safely. The specific operations are as follows:

[0053] Step 3.1: Install the fixed concrete specimen 820 to Figure 2 The concrete penetration device 800 is then installed in the Figure 1 High-precision concrete liquid penetration test integrated system;

[0054] Step 3.2: Check the liquid level of the sealed liquid holding box 100 to ensure that the liquid level is located at 2 / 3 to 4 / 5 of the total height of the box, and the probe 121 of the temperature detector 120 should be placed at 1 / 3 to 2 / 3 between the liquid level and the bottom of the box;

[0055] Step 3.3: During the equipment trial operation, set the switch of the self-priming turbine 200 and the pressure control button 204, preset the liquid pressure value, and the recommended range is 0.01-1MPa. Open the fine-tuning pressure ball valve 340, ensure that the sensor wiring is firm, check the upstream and downstream high-precision flow meters 400, 410, liquid pressure detector 600, and digital differential pressure sensor 700 to ensure that their data can be effectively collected by the paperless recorder and displayed on the computer terminal 910. Check the pipeline interface of the entire system to ensure that there is no leakage and it is well sealed.

[0056] Step 3.4: gradually increase the reading of the digital display 203 of the self-priming turbine 200 so that the pressure value of the liquid pressure detector 600 is always lower than the compressive strength of the concrete specimen 820. When the flow rate reaches % of the range of the upstream high-precision flow meter 400 or the pressure difference sensor, stop the pressure increase. If the pressure is insufficient, the air compressor 323 can be started to increase the pressure through the connecting conduit 320, the second one-way check valve 321, the air introduction pipe 322 and the air compressor 323. Keep this flow state, open the first ball valve 841, and observe the bubbles in the liquid collection container 830. When the bubbles are significantly reduced, close the first ball valve 841 to ensure that all gases in the system have been removed until the flow rate difference between the upstream and downstream high-precision flow meters 410 does not exceed 7% of the reading of the upstream high-precision flow meter 400. At this time, the system reaches a stable turbulent state. For the concrete specimen 820 with high density and poor permeability, the exhaust speed is slow, which may cause the liquid outlet pipe 813 to be in a negative pressure state. At this time, the second ball valve 844 can be selectively opened to partially pressurize liquid into the liquid outlet pipe 813 to accelerate the system filling process. After the operation is completed, the second ball valve 844 is closed.

[0057] Step 4: After the liquid fills the system, the test is officially started and data collection is performed. Adjust the reading of the digital display 203 of the self-priming turbine 200 so that the pressure difference ΔP of the digital pressure difference sensor 700 or the flow rate Q of the downstream flow meter reaches the minimum value. Start the temperature measuring instrument 120 and record the temperature T of the test liquid. Gradually increase the pressure control button 204 until the digital pressure difference sensor 700 or the downstream flow meter reaches 80% of its range. The data collection results are {ΔP│ΔP1, ΔP2, ΔP3, ..., ΔPn} and {Q│Q1, Q2, Q3, ..., Qn}, ΔPn corresponds to Qn respectively.

[0058] Step 5: Data processing. According to the temperature T of the test liquid, consult the "Fluid Physical Property Data Manual" to determine the liquid viscosity μ and density ρ. Import the collected {ΔP│ΔP1, ΔP2, ΔP3, ..., ΔPn} and {Q│Q1, Q2, Q3, ..., Qn} data into formula (1) for fitting:

[0059]

[0060] The linear coefficient A and nonlinear coefficient B are calculated and substituted into formulas (2) and (3) to calculate the inherent permeability coefficient K. v and inertial permeability coefficient K i :

[0061]

[0062]

[0063] The units of pressure gradient ΔP, linear coefficient A, nonlinear coefficient B and flow rate Q in formula (1) are Pa / m, kg / m5·s, kg / m8 and m3 / s respectively; the units of effective permeable area AS, viscosity μ and L in formulas (2) and (3) are m, Pa·s and m respectively; the water permeability coefficient K v , inertial permeability coefficient K i The units of and density ρ are m2, m and kg / m3 respectively.

[0064] The present invention can realize high-precision, real-time, dynamic monitoring and data collection of liquid permeability of concrete specimen 820 under different pressure and temperature conditions by integrating multiple high-precision sensing and control modules, and effectively reduce the risk of test liquid leakage through innovative closed liquid circulation design, further ensuring the safety of the experimental environment and the reliability of the test results. Specifically, the whole system design includes but is not limited to the following key components: First, the self-priming turbine 200 is used as the core liquid supply and regulation unit. By configuring the self-priming turbine 200 and the intelligent pressure control module, it can ensure that the liquid always maintains a stable pressure output under different test conditions; secondly, the closed liquid holding box 100 is used as the core unit for liquid storage and temperature control. Through the combination of the temperature detector and the box filter 130, it is ensured that the liquid is always in a highly pure state before and after entering the test cycle. At the same time, the liquid level control design of the holding box can effectively prevent liquid overflow. In addition, the system also includes a tank body 300 made of high-pressure steel, which is connected to the air compressor 323 through multiple connection ports. When the liquid pressure is insufficient, the air compressor 323 can be used for auxiliary pressurization to ensure that the pressure gradient during the liquid penetration process remains stable. In terms of data acquisition and monitoring, the present invention uses an upstream high-precision flowmeter 400, a downstream high-precision flowmeter 410 and a digital pressure difference sensor 700 for real-time data monitoring and recording. These data are synchronously transmitted to the computer through a multi-channel recorder 900. Combined with dedicated data acquisition and visualization software, the operator can observe and analyze the changes in various parameters during the test in real time, ensuring that the system has high accuracy and stability in observing the liquid penetration behavior of concrete under different working conditions. In particular, with the cooperation of the concrete penetration device 800, the system can accurately measure the penetration performance of concrete specimens 820 of different shapes and different rupture states under different pressures without affecting the structural integrity of the specimen, further enhancing the scope of application of the system.

[0065] The above are all preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby. Among them, the same parts are represented by the same figure numerals. It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "inside" and "outside" refer to the directions toward or away from the geometric center of a specific component, respectively. Therefore: All equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A high-precision concrete liquid penetration test integrated system, characterized in that: It comprises a sealed liquid containing box (100), a self-priming turbine (200), a tank body (300), an upstream high-precision flow meter (400), a downstream high-precision flow meter (410), a data acquisition port set (500), a downstream data acquisition port set (510), a liquid pressure detector (600), a digital differential pressure sensor (700), a concrete penetration device (800), and a multi-channel recorder (900); The self-priming turbine (200) is connected to the closed liquid holding tank (100) via a conduit, the closed liquid holding tank (100) is connected to the tank body (300) via a conduit, an air compressor (323) and a fine-tuning pressure ball valve (340) are provided on the tank body (300), and the tank body (300) is connected to an upstream high-precision flow meter (400) via the fine-tuning pressure ball valve (340); The upstream high-precision flow meter (400) is connected to the data acquisition port set (500) via a conduit; the data acquisition port set (500) is provided with no less than four ports and is respectively connected to a liquid pressure detector (600), a digital differential pressure sensor (700), and a concrete penetration device (800) via conduits; and the concrete penetration device (800) is connected to a downstream data acquisition port set (510); The downstream data acquisition port set (510) is provided with no less than three ports, and is connected to the digital differential pressure sensor (700) and the downstream high-precision flow meter (410) through a conduit, and the downstream high-precision flow meter (410) flows back to the closed liquid holding box (100) through the conduit; The upstream high-precision flow meter (400), the downstream high-precision flow meter (410), the liquid pressure detector (600), and the digital differential pressure sensor (700) are all connected to the multi-channel recorder (900) via lines, and the multi-channel recorder (900) is connected to the computer terminal (910) via lines.

2. A high-precision concrete liquid penetration test integrated system according to claim 1, characterized in that: The sealed liquid containing box (100) has no less than four connection ports, which are respectively connected to an outflow pipe (110), a pumping and filling pipe (111), a reflux pipe (112), and a temperature measuring instrument (120).

3. A high-precision concrete liquid penetration test integrated system according to claim 2, characterized in that: The self-priming turbine (200) has a suction end (201) and an output end (202), the outflow pipe (110) is connected to the suction end (201), and the self-priming turbine (200) generates pumping pressure for liquid and pumps the liquid from the output end (202) to the tank (300).

4. A high-precision concrete liquid penetration test integrated system according to claim 1, characterized in that: The tank body (300) has no less than three connection ports, which are respectively connected to an air compressor (323), a pump inlet pipe (312), and a check pipe (330); a third one-way check valve (331) is provided on the check pipe (330); the other end of the third one-way check valve (331) is connected to an intermediate pipe (332); the other end of the intermediate pipe (332) is connected to a fine-tuning pressure ball valve (340).

5. The high-precision concrete liquid penetration test integrated system according to claim 1 is characterized in that: The conduits are all made of high-pressure resistant materials, and the joints are all connected by high-pressure resistant threaded seals.

6. The high-precision concrete liquid penetration test integrated system according to claim 1 is characterized in that: The concrete infiltration device (800) comprises a penetration box (810), a liquid inlet pipe (812), a liquid outlet pipe (813), and a liquid collection container (830); the liquid inlet and the liquid outlet are both provided with liquid separation channels, and the liquid separation channels are both connected to ball valves, and the ball valves are both connected to the liquid collection container (830) through conduits; the liquid inlet and the liquid outlet are relatively arranged on two sides of the penetration box (810).

7. A high-precision concrete liquid penetration test integrated system according to claim 6, characterized in that: A concrete test piece (820) is sealed inside the penetration box (810), a side of the concrete test piece (820) is sealed with adhesive tape (816), and a gap between the penetration box (810) and the concrete test piece (820) is filled with liquid sealant (811).

8. A method for using the high-precision concrete liquid penetration test integrated system according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. performing vacuum saturation treatment on the concrete specimen (820) for 1 to 2 hours to reduce the time to reach a stable state, wherein the treated area includes the crack area of ​​the cracked concrete or the hydraulic exposure area of ​​the permeable concrete / porous ordinary concrete; S2. Before the concrete specimen (820) is installed, there is no restriction on the geometric shape of the specimen cross section, but it is necessary to ensure that the shape of the specimen cross section remains consistent in the direction of liquid flow or the height direction of the specimen, and to ensure that there is no lateral leakage in the communication path between the upper pressure surface and the lower pressure surface of the specimen; the concrete specimen (820) is initially sealed by using tape (816) on the side and upper and lower end surfaces, and the concrete specimen (820) is placed in the penetration box (810), and the gap between the penetration box (810) and the specimen is filled with liquid sealant (811), and after the sealant is dried, the tape (816) on the upper and lower pressure surfaces is cut off to expose the test area; S3, installing the sealed concrete specimen (820) into the concrete penetration device (800), and installing the device into an intelligent high-precision concrete liquid penetration test integrated system; S4, check the liquid level of the sealed liquid holding box (100), ensure that the liquid level is between 2 / 3 and 4 / 5 of the total height of the box, and place the probe (121) of the temperature detector (120) between 1 / 3 and 2 / 3 of the distance between the liquid level and the bottom of the box; S5. Test run the equipment, set the pressure value of the self-priming turbine (200) to 0.01 to 1 MPa, open the fine-tuning pressure ball valve (340), check that the wiring is in good contact, confirm that the collected data of the upstream and downstream high-precision flow meters (410), liquid pressure detectors (600), and digital differential pressure sensors (700) can be recorded and displayed by the multi-channel recorder (900) and displayed on the computer, and check all catheter interfaces to ensure that they are leak-proof and well sealed; S6. Gradually increase the pressure value of the self-priming turbine (200) to ensure that the pressure of the liquid pressure detector (600) is lower than the compressive strength of the concrete specimen (820). When the flow rate reaches 80% of the range of the upstream high-precision flow meter (400) or 80% of the range of the digital differential pressure sensor (700), stop increasing the pressure. If the pressure is insufficient, increase the pressure through the conduit and the air compressor (323). Test and maintain the flow state, observe the bubbles in the liquid collection container (830), close the first ball valve (841) to effectively remove the gas in the system, until the flow rate difference does not exceed 7% of the reading, it is considered that the turbulent state has been reached. For a denser specimen, the second ball valve (844) can be selectively opened to accelerate the time for the liquid to fill the entire system. S7. When the liquid fills the entire test system, formal testing and data collection begin; adjust the pressure value of the self-priming turbine (200) so that the reading of the digital differential pressure sensor (700) or the flow rate reading of the downstream high-precision flow meter (410) reaches the minimum; turn on the temperature measuring instrument (120), record the temperature of the test liquid, and gradually increase the pressure of the liquid pump system so that the collected reading reaches 80% of the range; record the collected results, which are continuous pressure gradients {ΔP│ΔP1, ΔP2, ΔP3, ..., ΔPn} and flow rates {Q│Q1, Q2, Q3, ..., Qn}, wherein the data have isochronous properties; S8. Query the fluid physical property data according to the liquid temperature value to confirm the viscosity and density of the liquid at this temperature; import the collected data {ΔP│ΔP1, ΔP2, ΔP3, …, ΔPn} and {Q│Q1, Q2, Q3, …, Qn} into the calculation, and use the formula to calculate the linear coefficient A and the nonlinear coefficient B, and then import the results into the formula to calculate the inherent permeability coefficient Kv and the inertial permeability coefficient Ki.

9. The method for using a high-precision concrete liquid penetration test integrated system according to claim 8, characterized in that: The calculation formula in step S8 is: The linear coefficient A and nonlinear coefficient B are calculated and substituted into formulas (2) and (3) to calculate the inherent permeability coefficient K. v and inertial permeability coefficient K i :

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