Color developing element and device for monitoring early carbonization depth of concrete in real time and operation process of color developing element and device

Abstract

The invention discloses a color developing element and device for monitoring the early carbonization depth of concrete in real time and an operation process of the color developing element and device, and belongs to the technical field of health monitoring evaluation and scientific research testing of engineering structure buildings. A covalent conjugate of Nile blue and alpha-cellulose, which can develop in a pH range of 10 to 13.5, is arranged in the developing tank. The device comprises the color developing element, can perform long-term real-time monitoring on the concrete carbonization depth, has the advantages of light and small structure, reversible color development, high sensitivity, easy data processing and the like, can effectively monitor the early carbonization behavior of the concrete for early warning, and reminds operation and employees to make a decision for engineering structure entity repair as soon as possible. According to the invention, accurate identification, dynamic tracking and intelligent early warning of the early carbonization behavior of the concrete are realized, reliable technical guarantee is provided for improving the safety of a building structure and prolonging the service life, and the method is suitable for popularization and application.

Description

Technical Field

[0001] The present invention belongs to the field of health monitoring and evaluation of engineering structure buildings and scientific research and testing technology, and specifically relates to a color display element, a device and an operation process thereof for real-time monitoring of the early carbonization depth of concrete. Background Art

[0002] The durability of reinforced concrete structures directly determines the safety and service life of buildings. Existing studies show that about 46% of reinforced concrete durability diseases are caused by steel corrosion, of which chloride ion corrosion and carbonization account for 30% and 32% respectively. Concrete carbonization is the core cause of steel corrosion, and its essence is carbon dioxide (CO 2 ) penetrates into the concrete and reacts with alkaline substances (such as calcium hydroxide) to form carbonates and water, causing the pH value of the concrete to gradually decrease. When the pH value is lower than 10, the concrete is completely carbonized, the passivation film on the surface of the steel bar is completely destroyed, the corrosion process is accelerated, and eventually the structure becomes unstable. Studies have shown that concrete carbonization is divided into three stages: uncarbonized (pH>13), early carbonized (pH 10~13) and fully carbonized (pH<10). However, existing technologies are insufficient in real-time monitoring of early carbonization, making it difficult to provide an early warning window for protection and repair.

[0003] At present, the mainstream detection method of concrete carbonation depth is based on the national standard "GB / T 50082-2009 Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete", which uses phenolphthalein reagent to perform color analysis on the damaged concrete section. However, the color change range of phenolphthalein (pH 8.2~10) can only identify the complete carbonation state, and cannot capture the critical changes of early carbonation (pH 10~13), resulting in serious lag in protective measures. In recent years, the scientific research field has tried to develop new sensors to break through this limitation. For example, CN112964640A proposed a fiber optic sensor for monitoring the carbonation depth of concrete, but it still has significant defects: (1) It relies on the mechanical structure of the sliding piston rod, and its sensitivity decreases due to friction or environmental erosion during long-term use; (2) The detection range and accuracy of pH sensitive materials are not clearly defined, making it difficult to accurately distinguish the carbonation stage; (3) The sensor lacks reversible response capability and cannot synchronously feedback the state recovery after the concrete is repaired, which restricts the realization of dynamic monitoring and closed-loop maintenance.

[0004] In summary, the existing technology for real-time, accurate and reversible monitoring of early carbonization of concrete still has key bottlenecks. It is urgent to develop a new sensing technology that covers a wide pH range (especially the sensitive range of pH 10-13) and has long-term stability and reversible response characteristics, so as to achieve active protection and intelligent operation and maintenance of the durability of reinforced concrete. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a color display element, a device and an operating process for real-time monitoring of the early carbonation depth of concrete. The device can perform long-term real-time monitoring of the carbonation depth of concrete, and has the advantages of light and small structure, reversible color display, high sensitivity, and easy data processing. It can effectively monitor the early carbonization behavior of concrete and provide early warning, reminding operators and practitioners to make early decisions on the physical repair of engineering structures.

[0006] The present invention is achieved through the following technical solutions: A color developing element for real-time monitoring of the early carbonization depth of concrete, wherein a plurality of color developing grooves are arranged in the color developing element, and a covalent bond of Nile blue and alpha-cellulose capable of coloring in the pH range of 10 to 13.5 is arranged in the color developing grooves.

[0007] Preferably, the preparation method of the covalent bond of Nile blue and α-cellulose is as follows: First, chloroform, α-cellulose and chloroacetyl chloride are added to a container in sequence and a magnetic rotor is built in. The container is connected to a reflux condenser, and the solution is refluxed and stirred at 80°C for 4 hours to achieve the attachment of acyl chloride groups to cellulose; then Nile blue is added to the solution, and then the solution is refluxed and stirred at 80°C for 4 hours to achieve amide coupling between Nile blue and functionalized cellulose; finally, the solution is filtered with water and acetone to remove loosely bound dyes.

[0008] Preferably, the color display element is made of transparent acrylic material and is covered with a polyamide film.

[0009] Preferably, the bandwidth of the color developing slot is 1 mm; the length of the color developing element is 5-50 mm.

[0010] A device for real-time monitoring of the early carbonization depth of concrete, comprising the above-mentioned color display element, as well as a pulse fiber optic light source, a three-primary color sensor, a color recognition processor and a carbonization assessment processing unit; wherein the color display element is connected to the pulse fiber optic light source and the three-primary color sensor respectively through sensing optical fibers, the pulse fiber optic light source and the three-primary color sensor are both connected to the color recognition processor through sensing optical fibers, and the color recognition processor is connected to the carbonization assessment processing unit through sensing optical fibers; the carbonization assessment processing unit is externally connected to a data receiving and early warning device.

[0011] The operation process of the above-mentioned device for real-time monitoring of the early carbonization depth of concrete comprises the following steps: Step 1) Before the concrete to be tested is poured, solidified and hardened, the color display element is embedded in the concrete test block to be tested along the carbonization direction, and a connector for an external pulse fiber optic light source and a three-primary color sensor is reserved on the outside of the concrete test block to be tested; Step 2) After the concrete test block is cured and dried, it is sealed on the side with paraffin or epoxy. Before being placed in the carbonization box, the color developing element is first connected to the pulse fiber light source and the three primary color sensor respectively, and then connected to other equipment to assemble together into the device for real-time monitoring of the early carbonization depth of concrete; Step 3) Place the treated concrete test block into the carbonization box and start the test; Step 4) The covalent bond of Nile blue and α-cellulose in the color developing tank of the color developing element develops color in the range of pH 10-13.5, and the pH value parameter is output through the pulse fiber light source; the three primary color sensor outputs the RGB three-color light source parameters; the color recognition processor adopts machine learning training, and is trained by the input RGB three-color light source parameters and pH value parameters, and the model with the smallest error after training is used as the color recognition processing model, and then the pH value is calculated by the processing model; after the color recognition processor outputs the pH value of each color developing tank of the color developing element, the carbonization evaluation processing unit determines the carbonization state of the concrete at the current corresponding position through the pH value, and divides different areas according to the position of the color developing tank; when the pH is less than 10, it is determined that the concrete is completely carbonized; when the pH is between 10 and 13, it is determined that the concrete is in the early carbonization stage; when the pH is greater than 13, it is determined that the concrete has not yet been carbonized; Step 5) The carbonization assessment processing unit outputs the obtained concrete carbonization state data to the data receiving and early warning device to identify whether the concrete to be tested is early carbonized or not, and warns the concrete that is already in the early carbonization stage.

[0012] Preferably, in step 1), the depth of the color-developing element pre-embedded into the concrete test block to be tested along the carbonization direction is half of the entire length of the concrete test block to be tested.

[0013] Preferably, the frequency range of the pulse fiber light source in step 4) is 1-600 kHz.

[0014] Preferably, in step 4), the three-primary-color sensor can support triple 16-bit RGB three-color light sources, with a fine color difference recognition accuracy of no more than 3 degrees and a response time of no more than 500 μs.

[0015] Preferably, in step 4), the training model of the color recognition processor includes a linear regression model, a support vector machine, a random forest, and an artificial neural network.

[0016] The beneficial effects of the present invention are as follows: (1) The device of the present invention can accurately capture subtle changes in the pH value of concrete within the range of 10 to 13 (corresponding to the early carbonization stage) through the synergistic effect of the highly sensitive color development unit and the three-primary color sensor, breaking through the limitation that the traditional phenolphthalein reagent can only detect complete carbonization (pH < 10). After the real-time monitoring data is quickly analyzed by the color recognition processor and the carbonization evaluation processing unit, an early warning signal can be immediately triggered to help operators detect carbonization risks early, provide a critical time window for concrete repair, avoid irreversible corrosion caused by the destruction of the steel passivation film, and significantly reduce the risk of structural instability.

[0017] (2) The color unit of the present invention uses a reversible pH-sensitive material (a covalent bond of Nile blue and α-cellulose). When the alkaline environment of the concrete is restored after repair, the color signal can be reversed synchronously, realizing dynamic tracking of the "carbonization-repair" state. This feature enables the device to be reused for a long time and supports instant verification of the repair effect, providing closed-loop data support for the full life cycle management of reinforced concrete structures and avoiding the monitoring interruption problem caused by irreversible response of traditional sensors.

[0018] (3) The device of the present invention abandons vulnerable mechanical sliding parts (such as the piston rod in CN112964640A) and significantly improves the long-term monitoring stability through the non-contact design of optical sensing and solid-state color display unit. Its lightweight and miniaturized structure is easy to embed into or on the surface of concrete, and can withstand complex working conditions such as temperature and humidity fluctuations and vibrations, ensuring continuous and reliable data collection. It is suitable for concealed deployment in various scenes such as bridges, tunnels, and buildings.

[0019] (4) In the device of the present invention, the combination of the three primary color sensor and the color recognition processor directly converts the color signal into a digital carbonization grade (uncarbonized / early carbonized / completely carbonized), and automatically outputs the evaluation result through the threshold algorithm of the carbonization evaluation processing unit. This technology gets rid of the dependence on manual visual interpretation, eliminates subjective errors, and supports wireless transmission and cloud management, helping to build a digital operation and maintenance system for smart construction sites and infrastructure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of a device for real-time monitoring of the early carbonization depth of concrete; Figure 2 It is a schematic diagram of the structure of a color display element for real-time monitoring of the early carbonization depth of concrete; Figure 1 , 2 In: 1. Concrete test block to be tested; 2. Paraffin or epoxy sealing insulation layer; 3. Color development element; 3-1. Color development tank; 4. Sensing optical fiber; 5. Pulse optical fiber light source; 6. Three primary color sensor; 7. Color recognition processor; 8. Carbonization evaluation processing unit; 9. Data receiving and early warning device; Figure 3 The monitoring data of the early carbonization depth inside the concrete structure after a certain period of time in Example 1; Figure 4 This is the monitoring data of the pH change of concrete at a certain location with carbonization time in Example 2. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Unless otherwise specified, the technical means used in the following examples are all conventional means well known to those skilled in the art, and the experimental methods without specifying the specific conditions are all conventional methods in the art.

[0023] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0024] A device for real-time monitoring of the early carbonation depth of concrete, such as Figure 1 As shown, it includes a color rendering element 3, a pulse fiber optic light source 5, a three-primary color sensor 6, a color recognition processor 7 and a carbonization evaluation processing unit 8; wherein the color rendering element 3 is connected to the pulse fiber optic light source 5 and the three-primary color sensor 6 respectively through a sensing fiber 4, the pulse fiber optic light source 5 and the three-primary color sensor 6 are both connected to the color recognition processor 7 through the sensing fiber 4, and the color recognition processor 7 is connected to the carbonization evaluation processing unit 8 through the sensing fiber 4; the carbonization evaluation processing unit 8 is externally connected to a data receiving and early warning device 9.

[0025] like Figure 2 As shown, the color developing element 3 is provided with a plurality of color developing grooves 3-1 with a width of 1 mm, and the color developing grooves 3-1 are provided with a covalent conjugate of Nile blue and α-cellulose. The covalent conjugate develops color in the pH range of 10 to 13.5, can react quickly within 10 seconds, is sensitive and reversible, and has an excellent effect on monitoring the early carbonization behavior of concrete.

[0026] The preparation method of the covalent bond of Nile blue and α-cellulose is shown in the following formula I:

[0027] Formula I In formula I: * represents a polar ion; x, y, z, and n are all natural numbers ≥ 1, wherein the value of n is 170 to 200.

[0028] The specific steps are as follows: First, 200 mL of chloroform, 10 g of α-cellulose and 5 mL of chloroacetyl chloride are added to a 500 mL flask in sequence and a magnetic rotor is built in. The flask is connected to a reflux condenser, and the solution is refluxed and stirred at 80°C for 4 h to achieve the attachment of acyl chloride groups to cellulose; then 0.1 g of Nile blue is added to the solution, and then the solution is refluxed and stirred at 80°C for 4 h to achieve amide coupling between Nile blue and functionalized cellulose; finally, the solution is filtered with water and acetone to remove loosely bound dyes.

[0029] In a preferred solution, the color display element 3 is made of a transparent acrylic material and is covered with a polyamide film.

[0030] The operation process of the above-mentioned device for real-time monitoring of the early carbonization depth of concrete is as follows: Figure 1 As shown, the specific steps are as follows: (1) Before the concrete to be tested is poured, solidified and hardened, the color display element 3 is pre-buried in the concrete test block 1 to be tested along the carbonization direction, wherein the embedding depth of the color display element 3 is approximately half (L / 2) of the overall length (L) of the concrete test block 1 to be tested, and a connector for an external pulse fiber optic light source 5 and a three-primary color sensor 6 is reserved on one side of the outside of the concrete test block 1 to be tested.

[0031] (2) After the concrete test block 1 is cured and dried, it is sealed with paraffin or epoxy side seals in accordance with GB50082-2024 to prepare a paraffin or epoxy sealing isolation layer 2. Before being placed in the carbonization box, the color display element 3 is first connected to the pulse fiber light source 5 and the three-primary color sensor 6 respectively, and then connected to other equipment to assemble the above-mentioned device for real-time monitoring of the early carbonization depth of concrete.

[0032] (3) Place the treated concrete specimen 1 into the carbonization box and start the test.

[0033] (4) The covalent bond of Nile blue and α-cellulose in the color development tank 3 - 1 of the color development element 3 develops color in the pH range of 10 to 13.5, and the pH value parameter is output through the pulse fiber light source 5 (frequency range of 1 to 600 kHz).

[0034] The three-primary color sensor 6 is an RGB three-color light source that supports triple 16-bit calculation, has a fine color difference recognition accuracy of no more than 3 degrees, a response time of no more than 500 μs, and outputs RGB three-color light source parameters.

[0035] The color recognition processor 7 adopts machine learning training, and the training models include linear regression model (Linearregression model, LM), support vector machine (Support Vector Machine, SVM), random forest (Randomforest, RF), artificial neural network (Artificial neural network, ANN), etc., and is trained by inputting RGB three-color light source parameters and pH value parameters. The model with the smallest error after training is used as the color recognition processing model, and then the pH value is calculated by the processing model.

[0036] A large number of artificial intelligence models were used to train a large number of pH parameters and three-color light source parameters in the early stage. In the subsequent implementation process, the pH of the concrete block 1 to be tested changed due to carbonation, and the color change in the color rendering element 3 was reversed through the artificial intelligence model to infer the pH value of the RGB three-color light source parameters, and then determine whether it was carbonized. The purpose of model training is to find a processing model with the smallest prediction error.

[0037] After the color recognition processor 7 outputs the pH value of each color development slot 3-1 of the color development element 3, the carbonization evaluation processing unit 8 determines the carbonization state of the concrete at the corresponding position according to the pH value, and divides different areas according to the position of the color development slot. When the pH is less than 10, the concrete is determined to be completely carbonized; when the pH is between 10 and 13, the concrete is determined to be in the early carbonization stage; when the pH is greater than 13, the concrete is determined to be not yet carbonized.

[0038] (5) The carbonization evaluation processing unit 8 outputs the obtained concrete carbonization state data to the data receiving and early warning device 9 to identify whether the concrete to be tested is early carbonized or not, and issues an alarm for concrete that is already in the early carbonization stage.

[0039] Example 1 The concrete mix ratio to be tested in this embodiment is shown in Table 1.

[0040] Table 1 Concrete mix ratio to be tested

[0041] After weighing the materials in Table 1 in proportion, mix the concrete according to the operating procedures of GB / T 50080-2016 "Standard for Test Methods for Properties of Ordinary Concrete Mixtures" and pour the freshly mixed concrete into a carbonization test mold of 100 mm × 100 mm × 400 mm.

[0042] Before the concrete is poured and hardened, a 50 mm long color display element is embedded in the concrete along the carbonization direction, and the concrete at the insertion position is smoothed. A connector for an external pulse fiber light source and a three-primary color sensor is reserved on the outside of the concrete.

[0043] After demolding, the test block should be immediately placed in a standard curing room with a temperature of 20±2℃ and a relative humidity of more than 95% for curing for 28 days.

[0044] The specimens were carbonized at 28 days of age, taken out from the standard curing room 2 days before the test, and then dried at 60 °C for 48 h.

[0045] After the drying process is completed, except for the two reserved opposite carbonized surfaces, the remaining surfaces are sealed with heated paraffin.

[0046] Before the specimen is placed in the carbonization box, the color developing element is connected to the pulse fiber optic light source and the three-primary color sensor, and a test system is built according to the device for real-time monitoring of the early carbonization depth of concrete, and then checked and tested.

[0047] Place the treated specimens in a carbonization box. The carbon dioxide concentration in the box must be maintained at 20±3%, the relative humidity must be controlled at 70±5%, and the temperature must be controlled within the range of 20±2℃.

[0048] Since the bandwidth of the color developing slot is 1 mm and the length of the color developing element is 50 mm, the color of different color developing slots changes continuously with the change of carbonization time. When the concrete is completely carbonized, the pH is less than 10. At this time, the color processor can record the time of complete carbonization at different positions.

[0049] Record the curves of different carbonation depths in concrete over time, such as Figure 3 As shown, with the extension of carbonization time, the carbonization depth inside the concrete continues to deepen, and the carbonization depth curve conforms to the curve trend of the theoretical model (the following formula), indicating that the device for real-time monitoring of the early carbonization depth of concrete of the present invention can accurately judge the change of the carbonization depth inside the concrete over time.

[0050]

[0051] Where: x is the carbonization depth (mm); k is the carbonation coefficient of concrete; t is the carbonation time of concrete (d).

[0052] Example 2 The concrete mix ratio to be tested in this embodiment is shown in Table 2.

[0053] Table 2 Concrete mix ratio to be tested

[0054] After weighing the materials in Table 2 in proportion, mix the concrete according to the operating procedures of GB / T 50080-2016 "Standard for Test Methods for Properties of Ordinary Concrete Mixtures" and pour the freshly mixed concrete into a carbonization test mold of 100 mm × 100 mm × 400 mm.

[0055] Before the concrete is poured and hardened, a 5 mm color display element is embedded in the concrete along the carbonization direction, and the concrete at the insertion position is smoothed. A connector for an external pulse fiber light source and a three-primary color sensor is reserved on the outside of the concrete.

[0056] After demolding, the test block should be immediately placed in a standard curing room with a temperature of 20±2℃ and a relative humidity of more than 95% for curing for 28 days.

[0057] The specimens were carbonized at 28 days of age, taken out from the standard curing room 2 days before the test, and then dried at 60 °C for 48 h.

[0058] After the drying process is completed, except for the two reserved opposite carbonized surfaces, the remaining surfaces are sealed with heated paraffin.

[0059] Before the specimen is placed in the carbonization box, the color developing element is connected to the pulse fiber optic light source and the three-primary color sensor, and a test system is built according to the device for real-time monitoring of the early carbonization depth of concrete, and then checked and tested.

[0060] Place the treated specimens in a carbonization box. The carbon dioxide concentration in the box must be maintained at 20±3%, the relative humidity must be controlled at 70±5%, and the temperature must be controlled within the range of 20±2℃.

[0061] Record the curve of pH change in concrete over time, such as Figure 4 As shown, in the early 14 days, the pH of this area remained constant due to carbonization occurring on the surface of the concrete; around 20 days after carbonization, due to the continuous deepening of the carbonization depth, this area began to gradually carbonize and the pH continued to decrease. At about 50 days, the concrete in this area was completely carbonized, indicating that the device for real-time monitoring of the early carbonization depth of concrete of the present invention can accurately determine the change of the carbonization state (pH value) of a certain position of the concrete over time.

[0062] The embodiments described above are only some embodiments of the present invention, rather than all embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. The scope of protection of the present invention shall be subject to the scope required by the claims. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work shall fall within the scope of protection of the present invention.

Claims

1. A color display element for real-time monitoring of early carbonization depth of concrete, characterized in that: The color developing element is provided with a plurality of color developing grooves, and the color developing grooves are provided with a covalent combination of Nile blue and α-cellulose which can develop color within a pH range of 10 to 13.

5.

2. A color display element for real-time monitoring of early carbonization depth of concrete according to claim 1, characterized in that: The preparation method of the covalent bond of Nile blue and α-cellulose is as follows: First, chloroform, α-cellulose and chloroacetyl chloride are added to a container in sequence and a magnetic rotor is built in. The container is connected to a reflux condenser, and the solution is refluxed and stirred at 80°C for 4 hours to achieve the attachment of acyl chloride groups to cellulose; then Nile blue is added to the solution, and then the solution is refluxed and stirred at 80°C for 4 hours to achieve amide coupling between Nile blue and functionalized cellulose; finally, the solution is filtered with water and acetone to remove loosely bound dyes.

3. The color display element for real-time monitoring of early carbonization depth of concrete according to claim 1, characterized in that: The color display element is made of transparent acrylic material and is covered with a polyamide film.

4. The color display element for real-time monitoring of early carbonization depth of concrete according to claim 1, characterized in that: The bandwidth of the color developing slot is 1 mm; the length of the color developing element is 5-50 mm.

5. A device for real-time monitoring of the early carbonization depth of concrete, characterized in that: It includes the color-displaying element as described in any one of claims 1 to 4, as well as a pulse fiber optic light source, a three-primary color sensor, a color recognition processor and a carbonization assessment processing unit; wherein the color-displaying element is connected to the pulse fiber optic light source and the three-primary color sensor respectively through sensing optical fibers, the pulse fiber optic light source and the three-primary color sensor are both connected to the color recognition processor through sensing optical fibers, and the color recognition processor is connected to the carbonization assessment processing unit through sensing optical fibers; the carbonization assessment processing unit is externally connected to a data receiving and early warning device.

6. The operating process of the device for real-time monitoring of early carbonization depth of concrete according to claim 5, characterized in that: The following steps are involved: Step 1) Before the concrete to be tested is poured, solidified and hardened, the color display element is embedded in the concrete test block to be tested along the carbonization direction, and a connector for an external pulse fiber optic light source and a three-primary color sensor is reserved on the outside of the concrete test block to be tested; Step 2) After the concrete test block is cured and dried, it is sealed on the side with paraffin or epoxy. Before being placed in the carbonization box, the color developing element is first connected to the pulse fiber light source and the three primary color sensor respectively, and then connected to other equipment to assemble together into the device for real-time monitoring of the early carbonization depth of concrete; Step 3) Place the treated concrete test block into the carbonization box and start the test; Step 4) the covalent bond of Nile blue and α-cellulose in the color developing tank of the color developing element develops color in the pH range of 10 to 13.5, and the pH value parameter is output through the pulse fiber light source; the three primary color sensor outputs the RGB three-color light source parameters; The color recognition processor adopts machine learning training, and is trained by inputting RGB three-color light source parameters and pH value parameters. The model with the smallest error after training is used as the color recognition processing model, and then the pH value is calculated by the processing model; after the color recognition processor outputs the pH value of each color display slot of the color display element, the carbonization evaluation processing unit determines the carbonization state of the concrete at the current corresponding position by the pH value, and divides different areas according to the position of the color display slot; when the pH is less than 10, it is determined that the concrete is completely carbonized; when the pH is between 10 and 13, it is determined that the concrete is in the early carbonization stage; when the pH is greater than 13, it is determined that the concrete has not yet been carbonized; Step 5) The carbonization assessment processing unit outputs the obtained concrete carbonization state data to the data receiving and early warning device to identify whether the concrete to be tested is early carbonized or not, and warns the concrete that is already in the early carbonization stage.

7. The operating process of the device for real-time monitoring of early carbonization depth of concrete according to claim 6 is characterized in that: Step 1) The depth of the color-developing element pre-embedded into the concrete test block to be tested along the carbonization direction is half of the overall length of the concrete test block to be tested.

8. The operating process of the device for real-time monitoring of early carbonization depth of concrete according to claim 6, characterized in that: Step 4) The frequency range of the pulse fiber light source is 1~600 kHz.

9. The operating process of the device for real-time monitoring of early carbonization depth of concrete according to claim 6, characterized in that: Step 4) The three-primary color sensor can support triple 16-bit calculation of RGB three-color light source, with a fine color difference recognition accuracy of no more than 3 degrees and a response time of no more than 500 μs.

10. The operating process of the device for real-time monitoring of early carbonization depth of concrete according to claim 6, characterized in that: Step 4) The training model of the color recognition processor includes a linear regression model, a support vector machine, a random forest, and an artificial neural network.

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