CN-121978316-A - Quick carbonization test device and method for concrete

CN121978316ACN 121978316 ACN121978316 ACN 121978316ACN-121978316-A

Abstract

The invention discloses a concrete rapid carbonization test device and method. The device comprises a pressure gas mixing system, a carbonization unit, a ventilation valve, a timer and a central controller, wherein the pressure gas mixing system comprises a carbon dioxide concentration control system, a temperature control system, a humidity control system, a pressure control system, a convection fan, a gas leakage valve and a pressure gas mixing cabin, the carbon dioxide concentration control system is used for monitoring and regulating and controlling the carbon dioxide concentration in the pressure gas mixing cabin, the temperature control system is used for monitoring and regulating and controlling the temperature in the pressure gas mixing cabin, the humidity control system is used for monitoring and regulating and controlling the relative humidity in the pressure gas mixing cabin, the pressure control system is used for monitoring and regulating and controlling the total pressure in the pressure gas mixing cabin, and the carbonization unit is used for accommodating a concrete test piece to be carbonized. The method realizes independent and accurate control and rapid stabilization of a plurality of parameters of gas temperature, humidity, carbon dioxide concentration and total pressure under the pressure condition.

Inventors

Mu ru
SHI YONGXING
CHEN JIAO
GUO JILONG
ZHOU JIANLONG
WANG XIAOWEI
CHEN XIANGSHANG
Qing longbang

Assignees

河北工业大学

Dates

Publication Date: 20260505
Application Date: 20260401

Claims (10)

1. The rapid carbonization test device for the concrete is characterized by comprising a pressure gas mixing system, a carbonization unit, a ventilation valve (12), a timer (13) and a central controller (20); The pressure gas mixing system comprises a carbon dioxide concentration control system, a temperature control system, a humidity control system, a pressure control system, a convection fan (8), a gas release valve (11) and a pressure gas mixing cabin (19); The carbon dioxide concentration control system comprises a carbon dioxide gas source, a carbon dioxide concentration sensor (1), a carbon dioxide gas inlet valve (10) and a carbon dioxide flowmeter (21), wherein a gas outlet of the carbon dioxide gas source is communicated with one gas inlet of a pressure mixed gas cabin (19) through a pipeline, the carbon dioxide gas inlet valve (10) and the carbon dioxide flowmeter (21) are arranged on the pipeline, and the carbon dioxide concentration sensor (1) is arranged in the pressure mixed gas cabin (19); The temperature control system comprises a temperature sensor (4) and a heat exchanger (5), wherein the temperature sensor (4) and the heat exchanger (5) are arranged in a pressure gas mixture cabin (19); The humidity control system comprises a humidity sensor (3), a dehumidifier (6) and a steam generator (7), wherein the humidity sensor (3), the dehumidifier (6) and the steam generator (7) are all arranged in a pressure mixed gas cabin (19); The pressure control system comprises a pressure sensor (2), a nitrogen inlet valve (9) and a nitrogen source, wherein an air outlet of the nitrogen source is communicated with the other air inlet of the pressure mixed gas cabin (19) through a pipeline, and the pipeline is provided with the nitrogen inlet valve (9), and the pressure sensor (2) is arranged in the pressure mixed gas cabin (19); the convection fan (8) is arranged in the pressure mixed gas cabin (19); the air release valve (11) is arranged on an exhaust pipeline of the pressure mixed gas cabin (19); The carbonization device comprises a plurality of carbonization units which are connected in parallel, wherein the air outlet end of a pressure mixed air cabin (19) is communicated with the air inlet end of each carbonization unit through a pipeline, each pipeline is provided with a respective ventilation valve (12), each ventilation valve (12) is provided with a timer (13), and a central controller (20) is in communication connection with a carbon dioxide concentration sensor (1), a pressure sensor (2), a humidity sensor (3), a temperature sensor (4), a heat exchanger (5), a dehumidifier (6), a steam generator (7), a nitrogen inlet valve (9), a carbon dioxide inlet valve (10), a gas leakage valve (11) and a carbon dioxide flowmeter (21).
2. The rapid concrete carbonization test device according to claim 1, wherein 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 gas cylinder, the pressure sensor (2) is a MICRO pressure sensor, the nitrogen gas source is a high-pressure nitrogen gas cylinder, the humidity sensor (3) is a Visala resistance type humidity sensor, the temperature sensor (4) is a PT100 platinum resistance temperature sensor, the heat exchanger (5) is a fin type heat exchanger, the dehumidifier (6) is a condensation dehumidifier, the steam generator (7) is an electric heating steam generator, and the carbon dioxide flowmeter (21) is an MF series flowmeter.
3. The rapid concrete carbonization test device according to claim 1, wherein the number of carbonization units is 1 to 10.
4. The rapid carbonization test device for concrete according to claim 1, wherein the carbonization unit comprises a carbonization box cover (14), a connecting piece (15), a sealing strip (16) and a carbonization barrel (17); The carbonization device comprises a carbonization cylinder (17) for placing a concrete test piece to be carbonized, a carbonization box cover (14) connected with the carbonization cylinder (17) in a sealing way through a connecting piece (15), a sealing strip (16) arranged at the joint of the carbonization box cover (14) and the carbonization cylinder (17), and an exhaust valve (18) arranged on the carbonization box cover (14) for exhausting air when steady-state pressure mixed gas is injected into a carbonization unit before carbonization starts and discharging air after carbonization test is finished.
5. The rapid carbonization test device for concrete according to claim 4, wherein the connecting member (15) is a connecting screw; the carbonization cylinder (17) is in a truncated cone shape, the carbonization box cover (14) is connected with the end face with the large diameter of the carbonization cylinder (17), and when steady-state pressure mixed gas is injected from the exhaust valve (18), under the action of the pressure mixed gas, the sealing between the cylinder wall of the carbonization cylinder (17) and a concrete test piece to be carbonized is pressed more tightly.
6. The rapid carbonization test device for concrete according to claim 1, wherein relays are arranged in front of a nitrogen inlet valve (9), a carbon dioxide inlet valve (10), a gas leakage valve (11) and a ventilation valve (12); the nitrogen gas inlet valve (9), the carbon dioxide inlet valve (10), the air leakage valve (11) and the air ventilation valve (12) can be controlled to be opened and closed, and the opening degree of the air leakage valve can be continuously adjusted to realize flow control from slight opening to full opening.
7. A method for testing rapid carbonization of concrete, characterized in that the method is based on the rapid carbonization testing device for concrete according to any one of claims 1-6, comprising the following steps: step 1, preparing and sealing a test piece, namely, a carbon dioxide concentration sensor (1), a pressure sensor (2), a humidity sensor (3), a temperature sensor (4), a heat exchanger (5), a dehumidifier (6), a steam generator (7), a convection fan (8), a nitrogen inlet valve (9), a carbon dioxide inlet valve (10), a gas release valve (11), a vent valve (12), a timer (13), an exhaust valve (18) of a carbonization unit, a central controller (20) and a carbon dioxide flowmeter (21) are all in a closed state, and pressing a plurality of concrete test pieces to be carbonized into respective preheated carbonization units and sealing; Step 2, pre-building a pressure foundation, namely opening a gas release valve (11) and externally connecting a vacuum pumping device to start vacuumizing, closing the gas release valve (11) after the vacuum pumping device displays that air in a pressure mixed gas cabin (19) is pumped out, then opening a convection fan (8), opening a carbon dioxide gas inlet valve (10) and a carbon dioxide flowmeter (21), injecting carbon dioxide into the pressure mixed gas cabin (19) through a carbon dioxide gas source, monitoring the real-time flow of the carbon dioxide through the carbon dioxide flowmeter (21), closing the carbon dioxide flowmeter (21) and the carbon dioxide gas inlet valve (10) when the monitored amount of the introduced carbon dioxide reaches the required amount of the carbon dioxide, then opening a pressure sensor (2), opening a nitrogen gas inlet valve (9), introducing nitrogen gas into the pressure mixed gas cabin (19) through the nitrogen gas source to pressurize, and monitoring the real-time total pressure in the pressure mixed gas cabin (19) through the pressure sensor (2), and closing the nitrogen gas inlet valve (9) when the real-time total pressure is not less than 90% of a set total pressure P; Step 3, temperature regulation and control, namely starting a temperature control system, continuously working a convection fan (8), stabilizing the real-time temperature in a pressure gas mixture cabin (19) at a set temperature T through the action of a heat exchanger (5), starting the heat exchanger (5) through a central controller (20) when the temperature sensor (4) monitors that the real-time temperature is higher than the set temperature T, and cooling until the real-time temperature is equal to the set temperature T, closing the heat exchanger (5), starting the heat exchanger (5) through the central controller (20) when the temperature sensor (4) monitors that the real-time temperature is lower than the set temperature T, heating and heating until the real-time temperature is equal to the set temperature T, closing the heat exchanger (5), and performing step 4 when the real-time temperature is equal to the set temperature T; step 4, regulating the relative humidity, namely starting a humidity control system, continuously operating a convection fan (8), stabilizing the real-time relative humidity in a pressure mixed gas cabin (19) at the set relative humidity through linkage operation of a dehumidifier (6) and a steam generator (7), when the real-time relative humidity is monitored by a humidity sensor (3) to be higher than the set relative humidity, operating the dehumidifier (6) to dehumidify until the real-time relative humidity is equal to the set relative humidity, and closing the dehumidifier (6), when the real-time relative humidity is monitored by the humidity sensor (3) to be lower than the set relative humidity, operating the steam generator (7) to humidify until the real-time relative humidity is equal to the set relative humidity, closing the steam generator (7), and when the real-time relative humidity is equal to the set relative humidity, performing step 5; step 5, pressure fine tuning, namely opening a nitrogen inlet valve (9), introducing nitrogen into the pressure gas mixture cabin (19) through a nitrogen source, and stabilizing the real-time total pressure of the pressure gas mixture cabin (19) at a set total pressure P by utilizing a pressure control system, when the pressure sensor (2) monitors that the real-time total pressure in the pressure gas mixture cabin (19) is lower than the set total pressure P, opening the nitrogen inlet valve (9), injecting nitrogen, and pressurizing until the real-time total pressure is equal to the set total pressure P, so as to form steady-state pressure gas mixture; Starting carbonization, namely starting a carbon dioxide concentration sensor (1), opening all ventilation valves (12), opening exhaust valves (18) of all carbonization units, enabling steady-state pressure mixed gas to enter each carbonization unit and exhaust air through the respective exhaust valve (18), ending the exhaust after at least 10 seconds of the air is introduced, closing the exhaust valve (18), and synchronously triggering a timer (13) to start timing, so that carbonization reaction starts; Step 7, continuously carbonizing, namely continuously working a carbon dioxide concentration sensor (1), a pressure sensor (2), a humidity sensor (3), a temperature sensor (4) and a convection fan (8) in the carbonizing reaction process, controlling the opening and closing of a heat exchanger (5), a dehumidifier (6), a steam generator (7), a nitrogen inlet valve (9) and a carbon dioxide inlet valve (10) by a central controller (20) according to data monitored and fed back by the carbon dioxide concentration sensor (1), the pressure sensor (2), the humidity sensor (3) and the temperature sensor (4) in real time, and dynamically adjusting the data to maintain the respective set values by the central controller (20) in a whole-process monitoring record mode to store real-time carbon dioxide concentration, real-time total pressure, real-time temperature and real-time relative humidity data; And 8, finishing and recycling, namely after the carbonization reaction time is reached, manually closing a convection fan (8), a ventilation valve (12) and a timer (13), controlling a central controller (20) to close a carbon dioxide concentration sensor (1), a pressure sensor (2), a humidity sensor (3), a temperature sensor (4), a heat exchanger (5), a dehumidifier (6), a steam generator (7), a nitrogen inlet valve (9) and a carbon dioxide inlet valve (10), opening a release valve (11) to release pressure, manually opening an exhaust valve (18) of a carbonization unit to release pressure, and taking out the carbonized concrete test piece.
8. The rapid carbonization test method for concrete according to claim 7, wherein in the step 1, a concrete specimen to be carbonized is pressed into a preheated carbonization unit and sealed, specifically, the surface of the concrete specimen to be carbonized is wiped clean, then molten sealing material is roll-coated on the surface of the concrete specimen to be carbonized, and then the surface of the concrete specimen to be carbonized is pressed into a preheated carbonization cylinder (17) by using a press machine, a sealing strip (16) and a carbonization box cover (14) are installed, the carbonization box cover (14) is fastened with the carbonization cylinder (17) by using a connecting piece (15), and the sealing strip (16) is combined to ensure the whole sealing performance of the carbonization unit; In the step 1, the sealing material is sealing wax; In the step 1, the temperature of a preheated carbonization barrel (17) is 60-80 ℃; In the step 1, the shape and the size of a concrete sample to be carbonized are matched with those of a carbonization cylinder (17), and the bottom surface of the concrete sample to be carbonized is level with the bottom surface of the carbonization cylinder (17); In the step 1, the concrete sample to be carbonized is in a truncated cone shape.
9. The rapid carbonization test method for concrete according to claim 7, wherein in the step 2, the required carbon dioxide amount is determined by a carbon dioxide substance amount n CO2 , and the carbon dioxide substance amount n CO2 is calculated according to a carbon dioxide partial pressure P CO2 and an ideal gas state equation, wherein T is a set temperature, R is an ideal gas constant, V is the volume of a pressure gas mixture chamber (19), P CO2 is a carbon dioxide partial pressure, P CO2 =C CO2 ×P;C CO2 is a set carbon dioxide volume concentration, and P is a set total pressure; In the step 2, the total pressure P is set to be 0.1-1 MPa, the control precision is +/-0.02 MPa, the carbon dioxide volume concentration C CO2 is set to be 2-30 vt, the control precision is +/-0.5%, the temperature T is set to be 20 ℃, and the control precision is +/-2 ℃; in step 4, the relative humidity is set to 70% and the control accuracy is set to + -5%.
10. The rapid carbonization test method for concrete according to claim 7, wherein in the step 7, the carbonization reaction time is 12 to 48 hours.

Description

Quick carbonization test device and method for concrete Technical Field The invention relates to the field of building material durability test, in particular to a concrete rapid carbonization test device and method. Background The durability of reinforced concrete structures is a key factor in determining their service life, and concrete carbonization is one of the most important causes of corrosion of the steel bars, leading to deterioration of structural properties. Therefore, the test and evaluation of the carbonization resistance of the concrete are of great importance for material development, engineering quality control and life prediction. At present, carbonization test methods of standard specifications (such as GB/T50082-2024 Standard for testing concrete Long-term Performance and durability) at home and abroad are generally carried out under normal pressure. The method typically subjects concrete test pieces to an environment of specific concentration of carbon dioxide (e.g., (20.0.+ -. 0.5) vt%), constant temperature (20.+ -. 2 ℃) and constant relative humidity (typically (70.+ -. 5)% RH), and the performance is evaluated by periodically measuring the depth of carbonization. However, this method has a significant limitation in that the test period is extremely long. In order to obtain representative carbonization depth data, the test often needs to last for months or even years, which cannot meet the urgent demands of modern engineering on rapid evaluation and iterative research and development of materials. To accelerate the carbonization process, a high pressure environment needs to be applied. Increasing the ambient pressure can significantly increase the rate of CO 2 diffusion, thereby greatly increasing the rate of carbonization. However, the existing high-pressure carbonization technical scheme has obvious technical bottlenecks that four core parameters of temperature, total pressure, carbon dioxide concentration and relative humidity are highly coupled and mutually interfered in a closed high-pressure system. Therefore, there is an urgent need for a novel apparatus and method capable of decoupling the above-mentioned multi-parameter interference and rapidly, accurately and stably establishing and maintaining a carbonization test environment meeting the standard specification requirements under pressure, so as to truly realize rapid and reliable evaluation of carbonization resistance of concrete. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a rapid concrete carbonization test device and a rapid concrete carbonization test method. The technical scheme for solving the technical problem of the device is that the invention provides a rapid concrete carbonization test device, which comprises a pressure gas mixing system, a carbonization unit, a ventilation valve, a timer and a central controller; the pressure gas mixing system comprises a carbon dioxide concentration control system, a temperature control system, a humidity control system, a pressure control system, a convection fan, a gas leakage valve and a pressure gas mixing cabin; The system comprises a pressure mixing gas cabin, a carbon dioxide concentration control system, a carbon dioxide flow meter, a carbon dioxide concentration sensor, a carbon dioxide inlet valve and a carbon dioxide flow meter, wherein the pressure mixing gas cabin is internally provided with a pressure base; The temperature control system is used for monitoring and regulating the temperature in the pressure mixed gas cabin and comprises a temperature sensor and a heat exchanger, wherein the temperature sensor and the heat exchanger are both arranged in the pressure mixed gas cabin; The humidity control system is used for monitoring and regulating the relative humidity in the pressure mixed gas cabin and comprises a humidity sensor, a dehumidifier and a steam generator, wherein the humidity sensor, the dehumidifier and the steam generator are all arranged in the pressure mixed gas cabin; The pressure control system is used for monitoring and regulating the total pressure in the pressure mixed gas cabin and comprises a pressure sensor, a nitrogen inlet valve and a nitrogen source, wherein the air outlet of the nitrogen source is communicated with the other air inlet of the pressure mixed gas cabin through a pipeline, and the nitrogen inlet valve is arranged on the pipeline; the convection fan is arranged in the pressure mixed gas cabin and used for promoting the uniform mixing and circulation of the pressure mixed gas in the pressure mixed gas cabin and ensuring the uniform concentration and temperature distribution of each component in the pressure mixed gas; The air release valve is arranged on an exhaust pipeline of the pressure mixed air cabin; The device comprises a plurality of carbonization units, a pressure mixture cabin, a plurality of carbonization units, a plurality of pressure mixture cabin and a plurality of pre