A concrete rapid carbonation test device and method

Abstract

The application discloses a kind of concrete rapid carbonation test device and method.The device includes pressure gas mixing system, carbonation unit, air valve, timer and central controller;Pressure gas mixing system includes carbon dioxide concentration control system, temperature control system, humidity control system, pressure control system, convection fan, air release valve and pressure mixed gas cabin;Carbon dioxide concentration control system is used to monitor and regulate the carbon dioxide concentration in pressure mixed gas cabin, temperature control system is used to monitor and regulate the temperature in pressure mixed gas cabin, humidity control system is used to monitor and regulate the relative humidity in pressure mixed gas cabin, pressure control system is used to monitor and regulate the total pressure in pressure mixed gas cabin, and carbonation unit is used to accommodate the concrete test piece to be carbonated.The method realizes the independent, accurate control and rapid stability of multiple parameters such as gas temperature, humidity, carbon dioxide concentration and total pressure under pressure condition.

Description

Technical Field

[0001] This invention relates to the field of building material durability testing, specifically a rapid carbonation testing device and method for concrete. Background Technology

[0002] The durability of reinforced concrete structures is a key factor determining their service life, and concrete carbonation is one of the main causes of steel corrosion and structural performance degradation. Therefore, the testing and evaluation of concrete's resistance to carbonation is crucial for materials research and development, engineering quality control, and service life prediction.

[0003] Currently, carbonation tests in domestic and international standards and specifications (such as GB / T50082-2024 "Standard for Test Methods of Long-Term Performance and Durability of Concrete") are generally conducted under normal pressure. This method typically places concrete specimens in an environment with a specific concentration of carbon dioxide (e.g., (20.0±0.5)vt%), a constant temperature (20±2℃), and a constant relative humidity (usually (70±5)%RH), evaluating performance by periodically measuring the carbonation depth. However, this method has a significant limitation: the testing cycle is extremely long. To obtain representative carbonation depth data, tests often need to last for months or even years, which cannot meet the urgent needs of modern engineering for rapid material evaluation and iterative research and development. To accelerate the carbonation process, a high-pressure environment is required. Increasing the environmental pressure can significantly increase the CO2 diffusion rate, thereby greatly accelerating the carbonation reaction rate. However, existing high-pressure carbonation technologies have significant technical bottlenecks: in a closed high-pressure system, the four core parameters—temperature, total pressure, carbon dioxide concentration, and relative humidity—are highly coupled and interfere with each other.

[0004] Therefore, there is an urgent need for a new device and method that can decouple the above-mentioned multi-parameter interference and can quickly, accurately, and stably establish and maintain a carbonation test environment that meets the requirements of standard specifications under pressure, so as to truly realize the rapid and reliable evaluation of the carbonation resistance performance of concrete. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a rapid carbonation testing device and method for concrete.

[0006] The technical solution of the present invention to solve the technical problem of the device is to provide a rapid carbonation test device for concrete, which includes a pressure gas mixing system, a carbonation unit, a venting valve, a timer and a central controller;

[0007] The pressurized gas mixing system includes a carbon dioxide concentration control system, a temperature control system, a humidity control system, a pressure control system, a convection fan, a vent valve, and a pressurized mixing chamber.

[0008] The carbon dioxide concentration control system is used to monitor and regulate the carbon dioxide concentration in the pressure mixing chamber. It includes a carbon dioxide gas source, a carbon dioxide concentration sensor, a carbon dioxide inlet valve, and a carbon dioxide flow meter. The outlet of the carbon dioxide gas source is connected to an inlet of the pressure mixing chamber through a pipeline. The pipeline is equipped with a carbon dioxide inlet valve and a carbon dioxide flow meter. The carbon dioxide flow meter is used to monitor the real-time flow rate of carbon dioxide introduced into the pressure mixing chamber during the pre-construction of the pressure foundation. The carbon dioxide concentration sensor is located inside the pressure mixing chamber.

[0009] The temperature control system is used to monitor and regulate the temperature inside the pressure mixing chamber, and includes temperature sensors and heat exchangers; both temperature sensors and heat exchangers are located inside the pressure mixing chamber.

[0010] The humidity control system is used to monitor and regulate the relative humidity inside the pressure mixing chamber, and includes a humidity sensor, a dehumidifier, and a steam generator; the humidity sensor, dehumidifier, and steam generator are all located inside the pressure mixing chamber.

[0011] The pressure control system is used to monitor and regulate the total pressure in the pressure mixing chamber, including a pressure sensor, a nitrogen inlet valve, and a nitrogen source; the outlet of the nitrogen source is connected to another inlet of the pressure mixing chamber through a pipeline, and a nitrogen inlet valve is installed on the pipeline; the pressure sensor is installed inside the pressure mixing chamber.

[0012] A convection fan is installed inside the pressure mixing chamber to promote uniform mixing and circulation of the pressure mixed gas within the chamber, ensuring uniform concentration and temperature distribution of each component in the pressure mixed gas.

[0013] The vent valve is located on the exhaust pipe of the pressure mixing chamber;

[0014] The carbonation unit is used to hold the concrete specimen to be carbonized; several carbonation units are connected in parallel; the outlet of the pressure mixing chamber is connected to the inlet of each carbonation unit through a pipeline, and each pipeline is equipped with its own ventilation valve; each ventilation valve is equipped with a timer, which is used to record the carbonation reaction time.

[0015] The central controller communicates with carbon dioxide concentration sensors, pressure sensors, humidity sensors, temperature sensors, heat exchangers, dehumidifiers, steam generators, nitrogen inlet valves, carbon dioxide inlet valves, vent valves, and carbon dioxide flow meters.

[0016] The technical solution of the present invention to solve the technical problem of the method is to provide a method for rapid carbonation testing of concrete. This method, based on the rapid carbonation testing device for concrete, includes the following steps:

[0017] Step 1, Specimen Preparation and Sealing: The carbon dioxide concentration sensor, pressure sensor, humidity sensor, temperature sensor, heat exchanger, dehumidifier, steam generator, convection fan, nitrogen inlet valve, carbon dioxide inlet valve, vent valve, ventilation valve, timer, exhaust valve of carbonation unit, central controller and carbon dioxide flow meter are all in the closed state. Several concrete specimens to be carbonized are pressed into their respective preheated carbonation units and sealed.

[0018] Step 2, Pre-establish the pressure foundation: Open the vent valve and connect the external vacuum device to begin vacuuming; when the vacuum device indicates that the air in the pressure mixing chamber has been completely removed, close the vent valve; then turn on the convection fan, open the carbon dioxide inlet valve and carbon dioxide flow meter, and inject carbon dioxide into the pressure mixing chamber through the carbon dioxide gas source, with the carbon dioxide flow meter monitoring the real-time flow rate of carbon dioxide; when the amount of carbon dioxide introduced reaches the required amount, close the carbon dioxide flow meter and carbon dioxide inlet valve; then turn on the pressure sensor, open the nitrogen inlet valve, and introduce nitrogen into the pressure mixing chamber through the nitrogen gas source to pressurize it; the pressure sensor monitors the real-time total pressure in the pressure mixing chamber, and when the real-time total pressure is not less than 90% of the set total pressure P, close the nitrogen inlet valve;

[0019] Step 3, Temperature Control: The temperature control system is activated, and the convection fan operates continuously. Through the heat exchanger, the real-time temperature within the pressure mixing chamber is stabilized at the set temperature T. When the temperature sensor detects that the real-time temperature is higher than the set temperature T, the central controller activates the heat exchanger for cooling until the real-time temperature equals the set temperature T, at which point the heat exchanger is turned off. When the temperature sensor detects that the real-time temperature is lower than the set temperature T, the central controller activates the heat exchanger for heating until the real-time temperature equals the set temperature T, at which point the heat exchanger is turned off. When the real-time temperature equals the set temperature T, proceed to Step 4.

[0020] Step 4, Relative Humidity Control: Activate the humidity control system. The convection fan operates continuously, and through the coordinated operation of the dehumidifier and steam generator, the real-time relative humidity in the pressure mixing chamber is stabilized at the set relative humidity. When the humidity sensor detects that the real-time relative humidity is higher than the set relative humidity, the dehumidifier operates to dehumidify until the real-time relative humidity equals the set relative humidity, then the dehumidifier is turned off. When the humidity sensor detects that the real-time relative humidity is lower than the set relative humidity, the steam generator operates to humidify until the real-time relative humidity equals the set relative humidity, then the steam generator is turned off. When the real-time relative humidity equals the set relative humidity, proceed to Step 5.

[0021] Step 5, Pressure Fine-tuning: Open the nitrogen inlet valve and introduce nitrogen into the pressure mixing chamber through the nitrogen source. Use the pressure control system to stabilize the real-time total pressure of the pressure mixing chamber at the set total pressure P. When the pressure sensor detects that the real-time total pressure in the pressure mixing chamber is lower than the set total pressure P, open the nitrogen inlet valve to inject nitrogen and pressurize until the real-time total pressure equals the set total pressure P, forming a steady-state pressure mixture.

[0022] Step 6: Start carbonization: Turn on the carbon dioxide concentration sensor, open all ventilation valves, and open the exhaust valves of all carbonization units to allow the steady-state pressure mixed gas to enter each carbonization unit and exhaust the air through its respective exhaust valve. After at least 10 seconds of ventilation, exhaust ends. Close the exhaust valves and simultaneously trigger the timer to start timing. The carbonization reaction begins.

[0023] Step 7, Continuous carbonization process: During the carbonization reaction, the carbon dioxide concentration sensor, pressure sensor, humidity sensor, temperature sensor and convection fan work continuously. The central controller controls the opening and closing of the heat exchanger, dehumidifier, steam generator, nitrogen inlet valve and carbon dioxide inlet valve based on the data monitored and fed back by the carbon dioxide concentration sensor, pressure sensor, humidity sensor and temperature sensor in real time. The central controller monitors, records and stores real-time carbon dioxide concentration, real-time total pressure, real-time temperature and real-time relative humidity data throughout the process, and dynamically adjusts to maintain them at their respective set values.

[0024] Step 8, End and Recovery: After the carbonation reaction time is reached, the carbonation test ends. Manually turn off the convection fan, ventilation valve and timer. The central controller controls the shutdown of the carbon dioxide concentration sensor, pressure sensor, humidity sensor, temperature sensor, heat exchanger, dehumidifier, steam generator, nitrogen inlet valve and carbon dioxide inlet valve, and opens the vent valve to release pressure. Manually open the exhaust valve of the carbonation unit to release gas, and then take out the carbonized concrete specimen.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) This invention can significantly accelerate the carbonation process of concrete, improve test efficiency, and has the advantages of low carbon dioxide consumption and leakage, and environmental protection. It constructs an integrated technical system of "pressurized carbonation device + intelligent image detection", which connects the carbonation environment control with the in-depth detection process, and solves the accuracy defects of traditional manual detection.

[0027] (2) The pressure mixed gas of the present invention can quickly penetrate concrete specimens, accelerate the carbonation process, and significantly shorten the carbonation test cycle (the traditional carbonation test cycle is 28 days).

[0028] (3) Due to the shortened carbonization cycle, the chamber, pipeline and carbonization unit are kept fully sealed during the test, the amount of carbon dioxide consumed and leaked is significantly reduced, and carbon dioxide is recovered when the test is completed, resulting in a significant reduction in carbon emissions.

[0029] (4) The apparatus of the present invention enables the precise and rapid preparation of a stable pressure-mixed gas that meets the requirements in advance within a pressure mixing chamber, and then introduces it into the carbonation chamber of a sealed concrete specimen to accelerate the carbonation reaction. The method of the present invention achieves independent, precise control and rapid stabilization of multiple parameters such as gas temperature, humidity, carbon dioxide concentration and total pressure under pressure conditions.

[0030] (5) In this invention, carbon dioxide and nitrogen are first injected into the pressure mixing chamber to establish a pressure base so that the total pressure is close to the set total pressure, and then the relative humidity is controlled to avoid multiple parameters being adjusted at the same time in the later stage. Moreover, premature humidification will cause water vapor to condense due to the increase in pressure. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall device of the present invention;

[0032] Figure 2 This is a schematic diagram of the carbonization unit of the present invention;

[0033] Figure 3 This is a schematic diagram of the carbonization cylinder of the present invention;

[0034] Figure 4 The figures are: (a) Curves showing the changes of various parameters in the pressure mixing chamber of Embodiment 1 of the present invention over time; (b) Curve showing the changes of carbon dioxide concentration over time; (c) Curve showing the changes of temperature over time; (d) Curve showing the changes of relative humidity over time; and (e) Curve showing the carbonized concrete specimen after spraying with phenolphthalein alcohol solution.

[0035] Figure 5 This is a diagram showing the carbonation zone division of the carbonated concrete specimens in Examples 1-5 of the present invention.

[0036] Figure 6 The distribution diagram of measuring points on the carbonized concrete specimens of Examples 1-4 of this invention;

[0037] Figure 7 This is a distribution diagram of measuring points on the actual carbonized concrete specimen of Example 1 of the present invention;

[0038] Figure 8The figures are: (a) Curves showing the changes of various parameters in the pressure mixing chamber of Embodiment 2 of the present invention over time; (b) Curve showing the changes of carbon dioxide concentration over time; (c) Curve showing the changes of temperature over time; (d) Curve showing the changes of relative humidity over time; and (e) Curve showing the carbonized concrete specimen after spraying with phenolphthalein alcohol solution.

[0039] Figure 9 The figures are: (a) Curves showing the changes of various parameters in the pressure mixing chamber of Embodiment 3 of the present invention over time; (b) Curve showing the changes of carbon dioxide concentration over time; (c) Curve showing the changes of temperature over time; (d) Curve showing the changes of relative humidity over time; and (e) Curve showing the carbonized concrete specimen after spraying with phenolphthalein alcohol solution.

[0040] Figure 10 The figures are: (a) Curves showing the changes of various parameters in the pressure mixing chamber of Embodiment 4 of the present invention over time; (b) Curve showing the changes of carbon dioxide concentration over time; (c) Curve showing the changes of temperature over time; (d) Curve showing the changes of relative humidity over time; and (e) Curve showing the carbonized concrete specimen after spraying with phenolphthalein alcohol solution.

[0041] Figure 11 The figures shown are: (a) Curves of monitoring data of various parameters in the pressure mixing chamber of Embodiment 5 of the present invention over time; (b) Curve of carbon dioxide concentration over time; (c) Curve of temperature over time; (d) Curve of relative humidity over time; (e) Carbonized concrete specimen after spraying phenolphthalein alcohol solution.

[0042] In the diagram, the components are: carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, heat exchanger 5, dehumidifier 6, steam generator 7, convection fan 8, nitrogen inlet valve 9, carbon dioxide inlet valve 10, vent valve 11, ventilation valve 12, timer 13, carbonization chamber cover 14, connector 15, sealing strip 16, carbonization cylinder 17, exhaust valve 18, pressure mixing chamber 19, central controller 20, and carbon dioxide flow meter 21. Detailed Implementation

[0043] Specific embodiments of the present invention are given below. These specific embodiments are only used to further illustrate the present invention in detail and do not limit the scope of protection of the present invention.

[0044] This invention provides a rapid carbonation test device for concrete (hereinafter referred to as the device, such as...). Figure 1 As shown, the device includes a pressurized gas mixing system, a carbonization unit, a vent valve 12, a timer 13, and a central controller 20;

[0045] The pressurized gas mixing system is used to prepare and store pressurized mixed gas, including a carbon dioxide concentration control system, a temperature control system, a humidity control system, a pressure control system, a convection fan 8, a vent valve 11, and a pressurized gas mixing chamber 19;

[0046] The carbon dioxide concentration control system is used to monitor and regulate the carbon dioxide concentration in the pressure mixing chamber 19. It includes a carbon dioxide gas source, a carbon dioxide concentration sensor 1, a carbon dioxide inlet valve 10, and a carbon dioxide flow meter 21. The outlet of the carbon dioxide gas source is connected to an inlet of the pressure mixing chamber 19 through a pipeline. The pipeline is equipped with a carbon dioxide inlet valve 10 and a carbon dioxide flow meter 21. The carbon dioxide flow meter 21 is used to monitor the real-time flow rate (preferably mass flow rate) of carbon dioxide introduced into the pressure mixing chamber 19 when the pressure foundation is pre-built. The carbon dioxide concentration sensor 1 is installed in the pressure mixing chamber 19 to monitor the real-time carbon dioxide concentration in the pressure mixing chamber 19.

[0047] The temperature control system is used to monitor and regulate the temperature inside the pressure mixing chamber 19, and includes a temperature sensor 4 and a heat exchanger 5. Both the temperature sensor 4 and the heat exchanger 5 are installed inside the pressure mixing chamber 19. The temperature sensor 4 is used to monitor the real-time temperature inside the pressure mixing chamber 19. The heat exchanger 5 is used to regulate the real-time temperature inside the pressure mixing chamber 19.

[0048] The humidity control system is used to monitor and regulate the relative humidity inside the pressure mixing chamber 19, and includes a humidity sensor 3, a dehumidifier 6, and a steam generator 7. The humidity sensor 3, dehumidifier 6, and steam generator 7 are all installed inside the pressure mixing chamber 19. The humidity sensor 3 is used to monitor the real-time relative humidity inside the pressure mixing chamber 19. The dehumidifier 6 is used to dehumidify and reduce the real-time relative humidity inside the pressure mixing chamber 19. The steam generator 7 is used to humidify and increase the real-time relative humidity inside the pressure mixing chamber 19.

[0049] The pressure control system is used to monitor and regulate the total pressure inside the pressure mixing chamber 19, including a pressure sensor 2, a nitrogen inlet valve 9, and a nitrogen source; the outlet of the nitrogen source is connected to another inlet of the pressure mixing chamber 19 through a pipeline, and the pipeline is equipped with a nitrogen inlet valve 9; the pressure sensor 2 is installed inside the pressure mixing chamber 19 to monitor the real-time total pressure inside the pressure mixing chamber 19.

[0050] The convection fan 8 is installed inside the pressure mixing chamber 19 to promote the uniform mixing and circulation of the pressure mixed gas inside the pressure mixing chamber 19, and to ensure that the concentration and temperature distribution of each component in the pressure mixed gas are uniform.

[0051] The vent valve 11 is installed on the exhaust pipe of the pressure mixing chamber 19 and is used to perform safe pressure relief and gas discharge operations when the pressure of the pressure mixing chamber 19 exceeds the limit, the carbon dioxide concentration exceeds the limit, or after the test is completed.

[0052] The carbonation unit is the site where the carbonation reaction occurs and is used to contain the concrete specimen to be carbonized; several carbonation units are connected in parallel; the outlet of the pressure mixing chamber 19 (preferably the carbon dioxide inlet and nitrogen inlet far away from the pressure mixing chamber 19) is connected to the inlet of each carbonation unit through a pipeline, and each pipeline is equipped with its own ventilation valve 12; each ventilation valve 12 is equipped with a timer 13, which is used to record the carbonation reaction time;

[0053] The central controller 20 is communicatively connected to the carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, heat exchanger 5, dehumidifier 6, steam generator 7, nitrogen inlet valve 9, carbon dioxide inlet valve 10, vent valve 11, and carbon dioxide flow meter 21. It is used to receive and store data from each sensor in real time, and output control commands according to the preset program to regulate the opening and closing status and degree of opening of the nitrogen inlet valve 9, carbon dioxide inlet valve 10, and vent valve 11, so that the environmental parameters of the pressure mixing chamber 19 can quickly reach and stabilize at the set values. During the carbonization test, the central controller 20 monitors, records, and stores real-time carbon dioxide concentration, real-time total pressure, real-time temperature, and real-time relative humidity data throughout the process.

[0054] Preferably, the carbon dioxide concentration sensor 1 is an NDIR infrared carbon dioxide concentration sensor; the carbon dioxide gas source is a high-pressure carbon dioxide cylinder; the pressure sensor 2 is a MICRO pressure sensor; the nitrogen gas source is a high-pressure nitrogen cylinder; the humidity sensor 3 is a Vasala resistance humidity sensor; the temperature sensor 4 is a PT100 platinum resistance temperature sensor; the heat exchanger 5 is a commercially available finned heat exchanger with heating and cooling functions; the dehumidifier 6 is a condensing dehumidifier, preferably a commercially available semiconductor refrigeration dehumidifier; the steam generator 7 is an electrically heated steam generator, preferably a commercially available electric heating tube steam generator; and the pressure mixing chamber 19 is a sealed cylindrical pressure vessel, with a main body material of 316 stainless steel and a volume of 0.2~2m³. 3The pipeline uses 316 stainless steel compression fittings with an outer diameter of 6mm or 8mm; the nitrogen inlet valve 9, carbon dioxide inlet valve 10, vent valve 11, vent valve 12, and exhaust valve 18 are commercially available direct-acting valves, with valve bodies and internal sealing materials of 316 stainless steel and polytetrafluoroethylene, respectively; the pipeline and valves are connected by 316 stainless steel compression fittings, forming a closed gas transmission channel with a pressure resistance of not less than 1.6MPa and resistance to carbon dioxide corrosion; the carbon dioxide flow meter 21 uses an MF series flow meter.

[0055] Preferably, the carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, heat exchanger 5, dehumidifier 6, steam generator 7, and convection fan 8 are all located at any position within the pressure mixing chamber 19.

[0056] Preferably, the number of carbonization units is 1 to 10.

[0057] Preferably, the carbonization unit (e.g.) Figure 2 (As shown) includes a carbonization chamber cover 14, a connector 15, a sealing strip 16, and a carbonization cylinder 17;

[0058] The carbonation cylinder 17 is used to place the concrete specimen to be carbonized; the carbonation chamber cover 14 is sealed to the carbonation cylinder 17 through the connector 15; a sealing strip 16 is provided at the connection between the carbonation chamber cover 14 and the carbonation cylinder 17 to further enhance the sealing performance; an exhaust valve 18 is provided on the carbonation chamber cover 14 to discharge air when a steady-state pressure mixed gas is injected into the carbonation unit before carbonation begins, and to release air after the carbonation test is completed.

[0059] Preferably, the connector 15 is a connecting screw, and more preferably a tie screw.

[0060] Preferably, the carbonization cylinder 17 is frustum-shaped, with the bottom diameter larger than the top diameter (e.g., ...). Figure 3 As shown, the height in this embodiment is 160mm.

[0061] Preferably, the carbonization chamber cover 14 is connected to the large-diameter end face (bottom face in this embodiment) of the carbonization cylinder 17. When pressurized mixed gas is injected from the exhaust valve 18, the seal between the cylinder wall of the carbonization cylinder 17 and the concrete specimen to be carbonized will become tighter and tighter under the action of the pressurized mixed gas, effectively enhancing the sealing performance.

[0062] Preferably, a relay is provided before each of the nitrogen inlet valve 9, the carbon dioxide inlet valve 10, the vent valve 11, and the ventilation valve 12; the relay operates after power is cut off to maintain the closed state of the nitrogen inlet valve 9, the carbon dioxide inlet valve 10, the vent valve 11, and the ventilation valve 12.

[0063] Preferably, the nitrogen inlet valve 9, carbon dioxide inlet valve 10, vent valve 11, and vent valve 12 can not only control their opening and closing (connecting or cutting off the airflow), but their opening degree can also be continuously adjusted to achieve flow control from slightly open to fully open. The flow rate is maximum when fully open and relatively low when slightly open. For fine-tuning, the valves can be opened to 5-20% of their full opening. Fine-tuning can be performed when the set value is reached to 80-90%.

[0064] This invention also provides a method for rapid carbonation testing of concrete (hereinafter referred to as the method), which is based on the aforementioned rapid carbonation testing device for concrete and includes the following steps:

[0065] Step 1, Specimen Preparation and Sealing: Carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, heat exchanger 5, dehumidifier 6, steam generator 7, convection fan 8, nitrogen inlet valve 9, carbon dioxide inlet valve 10, vent valve 11, ventilation valve 12, timer 13, exhaust valve of carbonization unit 18, central controller 20 and carbon dioxide flow meter 21 are all in the closed state. Press several concrete specimens to be carbonized into their respective preheated carbonization units and seal them.

[0066] Preferably, in step 1, pressing the concrete specimen to be carbonized into the preheated carbonization unit and sealing it involves: wiping the surface of the concrete specimen to be carbonized clean, then rolling molten sealing material onto the surface of the concrete specimen, then pressing it into the preheated carbonization cylinder 17 using a press, installing the sealing strip 16 and the carbonization box cover 14, and fastening the carbonization box cover 14 to the carbonization cylinder 17 with the connector 15, and combining the sealing strip 16 to ensure the overall sealing performance of the carbonization unit;

[0067] Preferably, in step 1, the sealing material is sealing wax. In this embodiment, the paraffin wax with 2% rosin is used as specified in GB / T50082-2024 "Standard for Test Methods of Long-Term Performance and Durability of Concrete".

[0068] Preferably, in step 1, the temperature of the preheated carbonization cylinder 17 is 60~80℃.

[0069] Preferably, in step 1, the shape and size of the concrete specimen to be carbonized match the carbonation cylinder 17; the bottom surface of the concrete specimen to be carbonized is flush with the bottom surface of the carbonation cylinder 17.

[0070] Preferably, in step 1, the concrete specimen to be carbonized is a concrete specimen that has reached the required age; the concrete specimen to be carbonized is a frustum shape, with the bottom diameter being larger than the top diameter (in this embodiment, the height is 150 mm).

[0071] Step 2, Pre-establish the pressure foundation: Open the vent valve 11 and connect the external vacuum device to start vacuuming; when the vacuum device shows that the air in the pressure mixing chamber 19 has been completely evacuated, close the vent valve 11; then turn on the convection fan 8, open the carbon dioxide inlet valve 10 and the carbon dioxide flow meter 21, and inject carbon dioxide into the pressure mixing chamber 19 through the carbon dioxide gas source. The carbon dioxide flow meter 21 monitors the real-time flow rate of carbon dioxide; when the amount of carbon dioxide introduced reaches the required amount, close the carbon dioxide flow meter 21 and the carbon dioxide inlet valve 10; then turn on the pressure sensor 2, open the nitrogen inlet valve 9, and introduce nitrogen into the pressure mixing chamber 19 through the nitrogen gas source to pressurize it; the pressure sensor 2 monitors the real-time total pressure in the pressure mixing chamber 19, and when the real-time total pressure is not less than 90% of the set total pressure P, close the nitrogen inlet valve 9;

[0072] Preferably, in step 2, the required amount of carbon dioxide is expressed as the amount of carbon dioxide, n. CO2 Determined; based on the partial pressure of carbon dioxide P CO2 The amount of substance n of carbon dioxide can be calculated using the ideal gas law. CO2 Ideal gas law P CO2 V=n CO2 RT, where T is the set temperature; R is the ideal gas constant, taken as 8.314; V is the volume of pressure mixing chamber 19; P CO2 For the partial pressure of carbon dioxide, P CO2 =C CO2 ×P;C CO2 P is the set carbon dioxide volume concentration; P is the set total pressure.

[0073] Preferably, in step 2, the total pressure P is set to 0.1~1MPa, with a control accuracy of ±0.02MPa; the carbon dioxide volume concentration (i.e., the ratio of the volume of carbon dioxide to the volume of the pressure mixing chamber 19) C is set. CO2 The VT% is 2~30% (preferably 20% VT%), with a control accuracy of ±0.5%; the volume of the pressure mixing chamber 19 is 0.2~2m³. 3 The set temperature T is 20℃, and the control accuracy is ±2℃.

[0074] Step 3, Temperature Control: The temperature control system is activated, and the convection fan 8 operates continuously. Through the heat exchanger 5, the real-time temperature within the pressure mixing chamber 19 is stabilized at the set temperature T. When the temperature sensor 4 detects that the real-time temperature is higher than the set temperature T, the central controller 20 activates the heat exchanger 5 to cool down the air until the real-time temperature equals the set temperature T, at which point the heat exchanger 5 is turned off. When the temperature sensor 4 detects that the real-time temperature is lower than the set temperature T, the central controller 20 activates the heat exchanger 5 to heat up the air until the real-time temperature equals the set temperature T, at which point the heat exchanger 5 is turned off. When the real-time temperature equals the set temperature T, proceed to Step 4.

[0075] Step 4, Relative Humidity Control: The humidity control system is activated, and the convection fan 8 operates continuously. Through the coordinated operation of the dehumidifier 6 and the steam generator 7, the real-time relative humidity within the pressure mixing chamber 19 is stabilized at the set relative humidity. When the humidity sensor 3 detects that the real-time relative humidity is higher than the set relative humidity, the dehumidifier 6 operates to dehumidify until the real-time relative humidity equals the set relative humidity, at which point the dehumidifier 6 is turned off. When the humidity sensor 3 detects that the real-time relative humidity is lower than the set relative humidity, the steam generator 7 operates to humidify until the real-time relative humidity equals the set relative humidity, at which point the steam generator 7 is turned off. When the real-time relative humidity equals the set relative humidity, proceed to Step 5.

[0076] Preferably, in step 4, the relative humidity is set to 70%, and the control accuracy is ±5%.

[0077] Step 5, Pressure Fine Adjustment: Open the nitrogen inlet valve 9 to introduce nitrogen into the pressure mixing chamber 19 through the nitrogen source. Use the pressure control system to precisely adjust the real-time total pressure of the pressure mixing chamber 19 to the set total pressure P. When the pressure sensor 2 detects that the real-time total pressure in the pressure mixing chamber 19 is lower than the set total pressure P, open the nitrogen inlet valve 9 to inject nitrogen and pressurize until the real-time total pressure equals the set total pressure P, forming a steady-state pressure mixture.

[0078] Step 6, Start carbonization: Turn on carbon dioxide concentration sensor 1, open all ventilation valves 12, open exhaust valves 18 of all carbonization units, so that the steady-state pressure mixed gas enters each carbonization unit and exhausts the air through its respective exhaust valve 18. After at least 10 seconds of ventilation, exhaust ends. Close exhaust valve 18 and synchronously trigger timer 13 to start timing. The carbonization reaction begins.

[0079] Step 7, Continuous carbonization process: During the carbonization reaction, carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, and convection fan 8 work continuously. The central controller 20 controls the opening and closing of heat exchanger 5, dehumidifier 6, steam generator 7, nitrogen inlet valve 9, and carbon dioxide inlet valve 10 based on the data monitored and fed back in real time by carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, and temperature sensor 4. The central controller 20 monitors, records, and stores real-time carbon dioxide concentration, real-time total pressure, real-time temperature, and real-time relative humidity data throughout the process, and dynamically adjusts them to maintain them at their respective set values.

[0080] Preferably, in step 7, the carbonization reaction time is 12~48h.

[0081] Step 8, End and Recovery: After the carbonization reaction time is reached, the carbonization test ends. Manually turn off the convection fan 8, ventilation valve 12 and timer 13. The central controller 20 controls the shutdown of carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, heat exchanger 5, dehumidifier 6, steam generator 7, nitrogen inlet valve 9 and carbon dioxide inlet valve 10, and opens the vent valve 11 to release pressure. Manually open the exhaust valve 18 of the carbonization unit to release gas, and then take out the carbonized concrete specimen.

[0082] Preferably, in step 8, the vent valve 11 is slowly opened to safely discharge the gas outdoors or to a dedicated recovery system (such as a commercially available SF6 gas recovery device) for safe depressurization and gas discharge.

[0083] Preferably, in step 8, the exhaust valve 18 in the carbonization unit is slowly opened to release the gas.

[0084] Example 1:

[0085] Step 1, Specimen Preparation and Sealing:

[0086] First, concrete specimens were prepared. The mass ratio of the concrete specimens was water:cement:fine aggregate:coarse aggregate:water-reducing agent = 170:350:812:1056:2.8, with a water-cement ratio of 0.486. Frustum-shaped concrete specimens (bottom diameter 185mm, top diameter 175mm, height 150mm) were prepared according to the mass ratio, with 3 specimens per group. The cement used was 42.5 grade ordinary Portland cement PO42.5. The fine aggregate was natural river sand with a fineness modulus of 2.5. The coarse aggregate was hard, rough-surfaced continuously graded crushed stone with a size of 5~20mm. The water-reducing agent used was a polycarboxylate-type high-efficiency water-reducing agent.

[0087] The concrete specimens were then subjected to standard curing for 28 days. After curing, they were taken out of the standard curing room 2 days before the test and then dried at 60°C for 48 hours to obtain the concrete specimens to be carbonated.

[0088] Then, wipe the surface of the dried frustum-shaped concrete specimen to be carbonized clean, and then roll molten sealing material onto the surface of the concrete specimen to be carbonized. Then, use a press to press it into the carbonization cylinder 17 at 70°C, install the sealing strip 16 and the carbonization box cover 14, and use the connector 15 to fasten the carbonization box cover 14 to the carbonization cylinder 17, and combine the sealing strip 16 to ensure the overall sealing performance of the carbonization unit.

[0089] Carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, heat exchanger 5, dehumidifier 6, steam generator 7, convection fan 8, nitrogen inlet valve 9, carbon dioxide inlet valve 10, vent valve 11, ventilation valve 12, timer 13, exhaust valve of carbonization unit 18, central controller 20 and carbon dioxide flow meter 21 are all in the closed state.

[0090] Step 2, Pre-establish the pressure foundation: Open the vent valve 11 and connect the external vacuum device to begin vacuuming; when the vacuum device indicates that the air in the pressure mixing chamber 19 has been completely removed, close the vent valve 11; then turn on the convection fan 8, open the carbon dioxide inlet valve 10 and the carbon dioxide flow meter 21, and inject carbon dioxide into the pressure mixing chamber 19 through the carbon dioxide gas source. The carbon dioxide flow meter 21 monitors the real-time flow rate of carbon dioxide; when the amount of carbon dioxide introduced reaches the required amount, close the carbon dioxide flow meter 21 and the carbon dioxide inlet valve 10; then turn on the pressure sensor 2, open the nitrogen inlet valve 9, and introduce nitrogen into the pressure mixing chamber 19 through the nitrogen gas source to pressurize it; the pressure sensor 2 monitors the real-time total pressure in the pressure mixing chamber 19 as 0.45 MPa, and close the nitrogen inlet valve 9; set the total pressure P to 0.5 MPa; set the carbon dioxide volume concentration C. CO2 20% vt%

[0091] Step 3, Temperature Control: The temperature control system is activated, and the convection fan 8 operates continuously. Through the heat exchanger 5, the real-time temperature within the pressure mixing chamber 19 is stabilized at the set temperature T. When the temperature sensor 4 detects that the real-time temperature is higher than the set temperature T, the central controller 20 activates the heat exchanger 5 to cool down the air until the real-time temperature equals the set temperature T, at which point the heat exchanger 5 is turned off. When the temperature sensor 4 detects that the real-time temperature is lower than the set temperature T, the central controller 20 activates the heat exchanger 5 to heat up the air until the real-time temperature equals the set temperature T, at which point the heat exchanger 5 is turned off. When the real-time temperature equals the set temperature T, proceed to Step 4. The set temperature T is 20°C.

[0092] Step 4, Relative Humidity Control: The humidity control system is activated, and the convection fan 8 operates continuously. Through the coordinated operation of the dehumidifier 6 and the steam generator 7, the real-time relative humidity within the pressure mixing chamber 19 is stabilized at the set relative humidity. When the humidity sensor 3 detects that the real-time relative humidity is higher than the set relative humidity, the dehumidifier 6 operates to dehumidify until the real-time relative humidity equals the set relative humidity, at which point the dehumidifier 6 is turned off. When the humidity sensor 3 detects that the real-time relative humidity is lower than the set relative humidity, the steam generator 7 operates to humidify until the real-time relative humidity equals the set relative humidity, at which point the steam generator 7 is turned off. When the real-time relative humidity equals the set relative humidity, proceed to Step 5; the set relative humidity is 65%.

[0093] Step 5, Pressure Fine-tuning: Open the nitrogen inlet valve 9 to introduce nitrogen into the pressure mixing chamber 19 through the nitrogen source. Use the pressure control system to stabilize the real-time total pressure of the pressure mixing chamber 19 at the set total pressure P. When the pressure sensor 2 detects that the real-time total pressure in the pressure mixing chamber 19 is lower than the set total pressure P, open the nitrogen inlet valve 9 to inject nitrogen and pressurize until the real-time total pressure equals the set total pressure of 0.5 MPa, forming a steady-state pressure mixture.

[0094] Step 6, Start carbonization: Turn on carbon dioxide concentration sensor 1, open all ventilation valves 12, open exhaust valves 18 of all carbonization units, so that the steady-state pressure mixed gas enters each carbonization unit and exhausts the air through its respective exhaust valve 18. After 30 seconds of ventilation, exhaust ends. Close exhaust valve 18 and synchronously trigger timer 13 to start timing. The carbonization reaction begins.

[0095] Step 7, Continuous Carbonization Process: During the carbonization reaction, carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, and convection fan 8 operate continuously. The central controller 20, based on the real-time monitoring and feedback data from these sensors, controls the opening and closing of heat exchanger 5, dehumidifier 6, steam generator 7, nitrogen inlet valve 9, and carbon dioxide inlet valve 10. The central controller 20 monitors, records, and stores real-time carbon dioxide concentration, total pressure, temperature, and relative humidity data throughout the process, and dynamically adjusts to maintain them at their respective set values. Environmental parameter data during the carbonization process are as follows: Figure 4 As shown in (a)-(d); the carbonization reaction time is 12h;

[0096] Step 8, End and Recovery: After the carbonization reaction time is reached, the carbonization test ends. Manually turn off the convection fan 8, ventilation valve 12 and timer 13. The central controller 20 controls the shutdown of carbon dioxide concentration sensor 1, pressure sensor 2, humidity sensor 3, temperature sensor 4, heat exchanger 5, dehumidifier 6, steam generator 7, nitrogen inlet valve 9 and carbon dioxide inlet valve 10, and opens the vent valve 11 to release pressure. Manually open the exhaust valve 18 of the carbonization unit to release gas, and then take out the carbonized concrete specimen.

[0097] Carbonation depth was measured on the carbonated concrete specimens; the method for measuring carbonation depth was as follows:

[0098] After carbonation, the carbonated concrete specimens were removed and deformed. After deforming, the powder on the cross-section was brushed off, and then a 1% phenolphthalein alcohol solution (containing 20% ​​distilled water) from GB / T50082-2024 "Standard for Test Methods of Long-Term Performance and Durability of Concrete" was sprayed. The resulting product is as follows. Figure 4 As shown in (e); subsequently, images are acquired using a high-resolution industrial camera (at least 24 megapixels in this embodiment) and color calibration and preprocessing are performed using existing image processing methods; finally, the central controller 20 automatically generates hundreds of measurement points and calculates depth values, outputs a structured inspection report containing the mean and standard deviation, and automatically stores it in the database.

[0099] In this embodiment, the carbonation zone division and measuring point distribution diagram of the carbonated concrete specimen are shown below. Figures 5-7 As shown, the carbonized area is uniformly divided into 100 units, and corresponding measuring points are generated. Then, the carbonization depth value of each measuring point is calculated, and a structured inspection report containing the mean and standard deviation is output and automatically stored in the database. The carbonization depth dataset is shown in Table 1 (unit: mm).

[0100] Table 1

[0101]

[0102] The arithmetic mean of the 100 measurements was calculated to be 17.7 mm, and the standard deviation was 1.4 mm.

[0103] Example 2:

[0104] This embodiment is exactly the same as Embodiment 1, except that:

[0105] The mass ratio of the concrete specimens was water:cement:fly ash:mineral powder:fine aggregate:coarse aggregate:water-reducing agent = 144:260:120:120:786:1000:6, with a water-cement ratio of 0.288. The set temperature T was 20℃, relative humidity was 65%, total pressure P was 0.5MPa, and carbon dioxide volume concentration C was... CO2The environmental parameter data during the carbonization process are as follows: 20% vt%. Figure 8 As shown in (a)-(d) in the figure; the carbonation reaction time was 24 h. The carbonation depth detection method was the same as in Example 1. The carbonized concrete specimens after spraying with phenolphthalein alcohol solution are shown in the figure. Figure 8 As shown in (e) above. The carbonization depth dataset is shown in Table 2 (unit: mm):

[0106] Table 2

[0107]

[0108] The arithmetic mean of the 100 measurements was calculated to be 29.8 mm, and the standard deviation was 1.8 mm.

[0109] Example 3:

[0110] This embodiment is exactly the same as Embodiment 1, except that:

[0111] The mass ratio of the concrete specimens was water:cement:fly ash:silica fume:fine aggregate:coarse aggregate:water-reducing agent = 160:280:120:30:830:970:4.5, with a water-cement ratio of 0.372. The set temperature T was 20℃, the set relative humidity was 65%, the set total pressure P was 0.5MPa, and the set carbon dioxide volume concentration C was... CO2 The environmental parameter data during the carbonization process are as follows: 20% vt%. Figure 9 As shown in (a)-(d) in the figure; the carbonation reaction time was 48 h. The carbonation depth detection method was the same as in Example 1. The carbonized concrete specimens after spraying with phenolphthalein alcohol solution are shown in the figure. Figure 9 As shown in (e) above. The carbonization depth dataset is shown in Table 3 (unit: mm):

[0112] Table 3

[0113]

[0114] The arithmetic mean of the 100 measurements was calculated to be 52.4 mm, and the standard deviation was 1.6 mm.

[0115] Example 4:

[0116] This embodiment is exactly the same as Embodiment 1, except that:

[0117] The mass ratio of the concrete specimens was water:cement:fly ash:fine aggregate:coarse aggregate:water-reducing agent = 158:300:80:810:1032:3.82, with a water-cement ratio of 0.416. The set temperature T was 20℃, relative humidity was 65%, total pressure P was 0.2MPa, and carbon dioxide volume concentration C was... CO2 The environmental parameter data during the carbonization process are as follows: 20% vt%. Figure 10 As shown in (a)-(d) in the figure; the carbonation reaction time was 12 hours. The carbonation depth detection method was the same as in Example 1. The carbonized concrete specimens after spraying with phenolphthalein alcohol solution are shown in the figure. Figure 10 As shown in (e) above. The carbonization depth dataset is shown in Table 4 (unit: mm):

[0118] Table 4

[0119]

[0120] The arithmetic mean of the 100 measurements was calculated to be 6.2 mm, and the standard deviation was 1.4 mm.

[0121] Example 5:

[0122] This embodiment is exactly the same as Embodiment 1, except that:

[0123] The mass ratio of the concrete specimens was water:cement:mineral powder:fine aggregate:coarse aggregate:water-reducing agent = 160:300:100:810:1020:4, with a water-cement ratio of 0.40. The set temperature T was 20℃, the set relative humidity was 65%, the set total pressure P was 0.8MPa, and the set carbon dioxide volume concentration C was... CO2 The environmental parameter data during the carbonization process are as follows: 20% vt%. Figure 11 As shown in (a)-(d) in the figure; the carbonation reaction time was 12 hours. The carbonation depth detection method was the same as in Example 1, except that the carbonation area was evenly divided into 50 units and corresponding measuring points were generated. The carbonized concrete specimens after spraying with phenolphthalein alcohol solution are shown in the figure. Figure 11 As shown in (e) above. The carbonization depth dataset is shown in Table 5 (unit: mm):

[0124] Table 5

[0125]

[0126] The arithmetic mean of the above 50 measurements was calculated to be 26.8 mm, and the standard deviation was 1.6 mm.

[0127] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A rapid carbonation testing device for concrete, characterized in that, The device includes a pressure gas mixing system, a carbonization unit, a vent valve (12), a timer (13), and a central controller (20). The pressurized gas mixing system includes a carbon dioxide concentration control system, a temperature control system, a humidity control system, a pressure control system, a convection fan (8), a vent valve (11), and a pressurized mixing chamber (19). The carbon dioxide concentration control system includes a carbon dioxide gas source, a carbon dioxide concentration sensor (1), a carbon dioxide inlet valve (10), and a carbon dioxide flow meter (21); the outlet of the carbon dioxide gas source is connected to an inlet of a pressure mixing chamber (19) through a pipeline, and a carbon dioxide inlet valve (10) and a carbon dioxide flow meter (21) are installed on the pipeline; the carbon dioxide concentration sensor (1) is installed inside the pressure mixing chamber (19); The temperature control system includes a temperature sensor (4) and a heat exchanger (5); both the temperature sensor (4) and the heat exchanger (5) are located inside the pressure mixing chamber (19); The humidity control system includes a humidity sensor (3), a dehumidifier (6), and a steam generator (7); the humidity sensor (3), the dehumidifier (6), and the steam generator (7) are all located inside the pressure mixing chamber (19); The pressure control system includes a pressure sensor (2), a nitrogen inlet valve (9), and a nitrogen source; the outlet of the nitrogen source is connected to another inlet of the pressure mixing chamber (19) through a pipeline, and a nitrogen inlet valve (9) is installed on the pipeline; the pressure sensor (2) is installed inside the pressure mixing chamber (19); A convection fan (8) is installed inside the pressure mixing chamber (19); The vent valve (11) is installed on the exhaust pipe of the pressure mixing chamber (19); Several carbonization units are connected in parallel; the outlet of the pressure mixing chamber (19) is connected to the inlet of each carbonization unit through a pipeline, and each pipeline is equipped with its own ventilation valve (12); each ventilation valve (12) is equipped with a timer (13); the central controller (20) is connected to the carbon dioxide concentration sensor (1), pressure sensor (2), humidity sensor (3), temperature sensor (4), heat exchanger (5), dehumidifier (6), steam generator (7), nitrogen inlet valve (9), carbon dioxide inlet valve (10), vent valve (11) and carbon dioxide flow meter (21).

2. The rapid carbonation test device for concrete according to claim 1, characterized in that, The carbon dioxide concentration sensor (1) adopts an NDIR infrared carbon dioxide concentration sensor; the carbon dioxide gas source adopts a high-pressure carbon dioxide cylinder; the pressure sensor (2) adopts a MICRO pressure sensor; the nitrogen gas source adopts a high-pressure nitrogen cylinder; the humidity sensor (3) adopts a Vasala resistance humidity sensor; the temperature sensor (4) adopts a PT100 platinum resistance temperature sensor; the heat exchanger (5) adopts a finned heat exchanger; the dehumidifier (6) adopts a condenser dehumidifier; the steam generator (7) adopts an electric heating steam generator; the carbon dioxide flow meter (21) adopts an MF series flow meter.

3. The rapid carbonation test device for concrete according to claim 1, characterized in that, The number of carbonization units ranges from 1 to 10.

4. The rapid carbonation test device for concrete according to claim 1, characterized in that, The carbonization unit includes a carbonization box cover (14), a connector (15), a sealing strip (16), and a carbonization cylinder (17). The carbonization cylinder (17) is used to place the concrete specimen to be carbonized; the carbonization box cover (14) is sealed to the carbonization cylinder (17) through the connector (15); a sealing strip (16) is provided at the connection between the carbonization box cover (14) and the carbonization cylinder (17); an exhaust valve (18) is provided on the carbonization box cover (14) to discharge air when a steady-state pressure mixed gas is injected into the carbonization unit before carbonization begins, and to release air after the carbonization test is completed.

5. The rapid carbonation test device for concrete according to claim 4, characterized in that, The connector (15) uses a connecting screw; The carbonization cylinder (17) is frustum-shaped; the carbonization box cover (14) is connected to the end face with the larger diameter of the carbonization cylinder (17). When a steady-state pressure mixed gas is injected from the exhaust valve (18), the seal between the cylinder wall of the carbonization cylinder (17) and the concrete specimen to be carbonized will become tighter and tighter under the action of the pressure mixed gas.

6. The rapid carbonation test device for concrete according to claim 1, characterized in that, A relay is installed before the nitrogen inlet valve (9), the carbon dioxide inlet valve (10), the vent valve (11), and the ventilation valve (12); The nitrogen inlet valve (9), carbon dioxide inlet valve (10), vent valve (11) and ventilation valve (12) can not only control opening and closing, but also continuously adjust the degree of opening to achieve flow control from slightly open to fully open.

7. A method for rapid carbonation testing of concrete, characterized in that, This method, based on the rapid carbonation test apparatus for concrete according to any one of claims 1-6, includes the following steps: Step 1, Specimen preparation and sealing: Carbon dioxide concentration sensor (1), pressure sensor (2), humidity sensor (3), temperature sensor (4), heat exchanger (5), dehumidifier (6), steam generator (7), convection fan (8), nitrogen inlet valve (9), carbon dioxide inlet valve (10), vent valve (11), ventilation valve (12), timer (13), exhaust valve of carbonization unit (18), central controller (20) and carbon dioxide flow meter (21) are all in the closed state. Press several concrete specimens to be carbonized into their respective preheated carbonization units and seal them. Step 2, Pre-establish pressure foundation: Open the vent valve (11) and connect the external vacuum device to start vacuuming; when the vacuum device shows that the air in the pressure mixing chamber (19) has been completely evacuated, close the vent valve (11); then turn on the convection fan (8), open the carbon dioxide inlet valve (10) and the carbon dioxide flow meter (21), inject carbon dioxide into the pressure mixing chamber (19) through the carbon dioxide gas source, and monitor the real-time flow of carbon dioxide through the carbon dioxide flow meter (21); when the amount of carbon dioxide introduced reaches the required amount of carbon dioxide, close the carbon dioxide flow meter (21) and the carbon dioxide inlet valve (10); then turn on the pressure sensor (2), open the nitrogen inlet valve (9), and introduce nitrogen into the pressure mixing chamber (19) through the nitrogen gas source to pressurize it; the pressure sensor (2) monitors the real-time total pressure in the pressure mixing chamber (19), and when the real-time total pressure is not less than 90% of the set total pressure P, close the nitrogen inlet valve (9). Step 3, Temperature Control: Start the temperature control system and the convection fan (8) works continuously. Through the action of the heat exchanger (5), the real-time temperature in the pressure mixing chamber (19) is stabilized at the set temperature T. When the temperature sensor (4) detects that the real-time temperature is higher than the set temperature T, the heat exchanger (5) is turned on through the central controller (20) to cool down until the real-time temperature equals the set temperature T, and then the heat exchanger (5) is turned off. When the temperature sensor (4) detects that the real-time temperature is lower than the set temperature T, the heat exchanger (5) is turned on through the central controller (20) to heat up until the real-time temperature equals the set temperature T, and then the heat exchanger (5) is turned off. When the real-time temperature equals the set temperature T, proceed to step 4. Step 4, relative humidity control: Start the humidity control system, the convection fan (8) works continuously, and through the linkage of the dehumidifier (6) and the steam generator (7), the real-time relative humidity in the pressure mixing chamber (19) is stabilized at the set relative humidity; when the humidity sensor (3) detects that the real-time relative humidity is higher than the set relative humidity, the dehumidifier (6) works to dehumidify until the real-time relative humidity is equal to the set relative humidity, and then the dehumidifier (6) is turned off; when the humidity sensor (3) detects that the real-time relative humidity is lower than the set relative humidity, the steam generator (7) works to humidify until the real-time relative humidity is equal to the set relative humidity, and then the steam generator (7) is turned off; when the real-time relative humidity is equal to the set relative humidity, proceed to step 5; Step 5, Pressure fine adjustment: Open the nitrogen inlet valve (9) and introduce nitrogen into the pressure mixing chamber (19) through the nitrogen source. Use the pressure control system to stabilize the real-time total pressure of the pressure mixing chamber (19) at the set total pressure P. When the pressure sensor (2) detects that the real-time total pressure in the pressure mixing chamber (19) is lower than the set total pressure P, open the nitrogen inlet valve (9) to inject nitrogen and pressurize until the real-time total pressure is equal to the set total pressure P, forming a steady-state pressure mixture. Step 6, Start carbonization: Turn on the carbon dioxide concentration sensor (1), open all the ventilation valves (12), open the exhaust valves (18) of all carbonization units, so that the steady-state pressure mixed gas enters each carbonization unit and exhausts the air through its respective exhaust valve (18). After at least 10 seconds of ventilation, the exhaust ends. Close the exhaust valve (18), and synchronously trigger the timer (13) to start timing. The carbonization reaction begins. Step 7, Continuous carbonization process: During the carbonization reaction, the carbon dioxide concentration sensor (1), pressure sensor (2), humidity sensor (3), temperature sensor (4) and convection fan (8) work continuously. The central controller (20) controls the opening and closing of the heat exchanger (5), dehumidifier (6), steam generator (7), nitrogen inlet valve (9) and carbon dioxide inlet valve (10) based on the data monitored and fed back by the carbon dioxide concentration sensor (1), pressure sensor (2), humidity sensor (3) and temperature sensor (4) in real time. The central controller (20) monitors, records and stores the real-time carbon dioxide concentration, real-time total pressure, real-time temperature and real-time relative humidity data throughout the process, and dynamically adjusts them to maintain them at their respective set values. Step 8, End and Recovery: After the carbonization reaction time is reached, the carbonization test ends. Manually turn off the convection fan (8), ventilation valve (12) and timer (13). The central controller (20) controls the shutdown of carbon dioxide concentration sensor (1), pressure sensor (2), humidity sensor (3), temperature sensor (4), heat exchanger (5), dehumidifier (6), steam generator (7), nitrogen inlet valve (9) and carbon dioxide inlet valve (10), and opens the vent valve (11) to release pressure. Manually open the exhaust valve (18) of the carbonization unit to release gas, and then take out the carbonized concrete specimen.

8. The rapid carbonation test method for concrete according to claim 7, characterized in that, In step 1, the concrete specimen to be carbonized is pressed into the preheated carbonization unit and sealed. Specifically, the surface of the concrete specimen to be carbonized is wiped clean, and then molten sealing material is rolled onto the surface of the concrete specimen to be carbonized. Then, a press is used to press it into the preheated carbonization cylinder (17), the sealing strip (16) and the carbonization box cover (14) are installed, and the carbonization box cover (14) is fastened to the carbonization cylinder (17) with the connector (15). Combined with the sealing strip (16), the overall sealing performance of the carbonization unit is ensured. In step 1, the sealing material is sealing wax; In step 1, the temperature of the preheated carbonization cylinder (17) is 60~80℃; In step 1, the shape and size of the concrete specimen to be carbonized are matched with the carbonation cylinder (17); the bottom surface of the concrete specimen to be carbonized is flush with the bottom surface of the carbonation cylinder (17); In step 1, the concrete specimen to be carbonized is a frustum shape.

9. The rapid carbonation test method for concrete according to claim 7, characterized in that, In step 2, the required amount of carbon dioxide is expressed as the amount of carbon dioxide, n. CO2 Determined; based on the partial pressure of carbon dioxide P CO2 The amount of substance n of carbon dioxide can be calculated using the ideal gas law. CO2 Ideal gas law P CO2 V=n CO2 RT, where T is the set temperature; R is the ideal gas constant; V is the volume of the pressure mixing chamber (19); P CO2 For the partial pressure of carbon dioxide, P CO2 =C CO2 ×P;C CO2 P is the set carbon dioxide volume concentration; P is the set total pressure. In step 2, the total pressure P is set to 0.1~1MPa, with a control accuracy of ±0.02MPa; the carbon dioxide volume concentration C is set. CO2 The VT is 2~30%, and the control accuracy is ±0.5%; the set temperature T is 20℃, and the control accuracy is ±2℃. In step 4, the relative humidity is set to 70%, and the control accuracy is ±5%.

10. The rapid carbonation test method for concrete according to claim 7, characterized in that, In step 7, the carbonization reaction time is 12~48h.

Images