Concrete quality three-level monitoring device and method

Abstract

The invention discloses a concrete quality three-level monitoring device and method, and belongs to the technical field of concrete construction. The method aims at solving the cracking problem caused by factors such as temperature stress and shrinkage stress in mass concrete construction and the key technical problems such as data islanding phenomenon and regulation and control lag in an existing monitoring method. According to the technical scheme, a three-level monitoring system of pouring layer-cooling layer-structural layer is constructed, and various key parameters such as temperature, humidity, flow velocity and cooling water flow of concrete in pouring, cooling and stabilizing stages are accurately monitored in real time; the central controller is used for carrying out real-time analysis processing and dynamic regulation and control on the data, so that comprehensive, accurate and continuous monitoring on the concrete construction quality is realized; the method is mainly applied to monitoring scenes of mass concrete construction quality, concrete cracking can be effectively prevented, the engineering quality and safety are remarkably improved, and reliable technical guarantee is provided for the concrete construction industry.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mass concrete construction quality control, and particularly relates to a concrete quality three-level monitoring device and method. BACKGROUND

[0002] Concrete is the most widely used building material in civil engineering field, and its quality has a decisive influence on the safety and durability of engineering structures. In modern large-scale engineering, especially in the construction process of mass concrete structures (such as hydraulic dams, large foundations, nuclear power plant containment vessels, etc.), the construction mode of centralized mixing, long-distance transportation to the construction site and pouring is generally adopted. This mode puts forward very high requirements for concrete quality management, which needs to cover the whole life cycle from production, transportation, pouring, cooling and curing to long-term service.

[0003] However, at present, the construction quality control of mass concrete structures mainly focuses on the quality control of the production process of the mixing station, including the monitoring of raw material processing and mixing stage, and the local quality control of the site pouring stage, such as temperature and humidity monitoring. But there are still many significant deficiencies in the whole cycle monitoring.

[0004] Firstly, the monitoring process is discontinuous. The current monitoring system focuses on the initial stage of concrete production, and the monitoring measures for the subsequent critical temperature control (cooling water process) and long-term performance of the structure (internal temperature and strain state) are insufficient, resulting in a break in the monitoring process in the time dimension. For example, in the water cooling stage after concrete pouring, how to accurately monitor and adjust the flow, temperature and water pressure of cooling water to ensure that the internal temperature rise and temperature drop rate of concrete meet the temperature control design requirements is a major challenge faced by current technology. The existing technology often cannot realize continuous monitoring and dynamic adjustment of this process, increasing the risk of concrete cracking due to temperature stress. For example, CN120101951A discloses an intelligent temperature monitoring system and method for mass concrete, which can monitor the temperature of concrete, but does not fully consider the continuous monitoring of the cooling water process, a key link. In the stage from concrete pouring to the completion of water cooling, it may not be able to fully and continuously obtain the dynamic correlation information between the temperature change of concrete and the cooling water parameters, thereby affecting the accurate evaluation of the temperature control effect of concrete.

[0005] Secondly, the key parameter monitoring is missing. For the flow rate of the concrete into the warehouse (directly affecting the uniformity of the concrete), the core parameters (including flow, water temperature, water pressure) during the water cooling process, and the actual temperature field and stress-strain state inside the structure, there is currently a lack of effective monitoring technology. This makes it difficult for construction personnel to fully understand the actual state of the concrete during the construction process, thereby increasing the quality risk. For example, the inability to monitor and adjust the flow and water temperature of the cooling water in real time can lead to excessive internal temperature gradient of the concrete, causing cracking. The system and method disclosed in CN120101951A mainly focus on temperature monitoring, and do not involve key parameters such as the flow rate of the concrete into the warehouse and the water pressure during the water cooling process, making it difficult to form a comprehensive parameter monitoring system for the concrete construction process, and not conducive to timely discovering potential quality problems caused by abnormal parameters.

[0006] Thirdly, the feedback control mechanism is insufficient. The current monitoring system is limited to the data collection stage, and lacks intelligent early warning and closed-loop control functions based on multi-link and multi-parameter comprehensive analysis. This leads to difficulties in adjusting construction parameters in a timely manner to prevent potential quality problems such as temperature cracks and stress overruns, which is particularly prominent in complex and variable construction environments. For example, when the internal temperature of the concrete is too high, existing technologies often cannot automatically adjust the operating parameters of the cooling system, but require manual intervention, which not only increases management costs, but also reduces the timeliness and effectiveness of the control. The system and method disclosed in CN120101951A are unable to automatically adjust and close-loop control the construction parameters such as the cooling system based on temperature changes after obtaining temperature data, and still rely on manual judgment and operation when temperature anomalies occur, which cannot quickly and accurately respond to the impact of temperature changes on concrete quality.

[0007] Fourthly, the whole-cycle monitoring is incomplete. The current monitoring system fails to fully cover the quality monitoring needs from the start of concrete into the warehouse, through the water cooling peak period, to the completion of the structure temperature stabilization and stress release. This incompleteness makes it difficult for engineers to assess the long-term performance of concrete structures with sufficient data support. For example, for the performance changes and safety assessment of concrete structures during long-term operation, existing technologies often cannot provide comprehensive and continuous data support, affecting the judgment of the long-term stability of the structure. The system and method disclosed in CN120101951A mainly focus on temperature monitoring during the concrete construction phase, and involve less performance monitoring of concrete structures during long-term service, making it difficult to meet the needs of whole-cycle monitoring, and not conducive to the assessment and maintenance of the long-term safety and durability of concrete structures.

[0008] Furthermore, the prior art also lacks a multi-parameter collaborative analysis mechanism. Although some monitoring systems implement multi-parameter monitoring, there is a lack of effective collaborative analysis mechanism between parameters, leading to monitoring data islandization and difficulty in forming a comprehensive evaluation of concrete quality. For example, the multi-parameter concrete monitoring system described in US20100280755A1 can monitor temperature, humidity, and stress parameters of concrete simultaneously, but does not mention how to comprehensively analyze these parameters through a central controller to achieve more accurate quality control. This data islandization phenomenon seriously restricts the utilization efficiency of monitoring data and reduces the accuracy and reliability of monitoring results. The system and method disclosed in CN120101951A also lack multi-parameter collaborative analysis. Only temperature parameters are monitored and analyzed, and temperature is not comprehensively correlated and analyzed with other parameters that may affect concrete quality, making it difficult to comprehensively and accurately evaluate the quality of concrete.

[0009] At the same time, the prior art has poor monitoring adaptability in extreme environments. In high-cold and high-altitude areas, due to the harsh environmental conditions, concrete construction quality control faces greater challenges. The prior art often cannot adapt to the monitoring needs in such extreme environments, leading to quality problems such as cracking and leakage of concrete structures during long-term operation, seriously affecting the safety and durability of the project. For example, in low-temperature conditions, the sensitivity and stability of sensors may be affected, leading to inaccurate monitoring data; at the same time, the cooling control strategy of existing systems may not effectively respond to the influence of atmospheric pressure changes in high-altitude areas on cooling effect. The system and method disclosed in CN120101951A do not fully consider the influence of extreme environmental factors on monitoring equipment and monitoring effect, and may not work normally or provide accurate and reliable monitoring data in harsh environments such as high-cold and high-altitude, thereby affecting effective control of concrete construction quality.

[0010] In summary, the prior art has specific problems such as discontinuous monitoring process, lack of key parameter monitoring, insufficient feedback control mechanism, incomplete whole-cycle monitoring, lack of multi-parameter collaborative analysis mechanism, and poor monitoring adaptability in extreme environments in the field of mass concrete construction quality control. The mass concrete intelligent temperature monitoring system and method disclosed in CN120101951A also fails to fully solve these problems. These problems not only restrict the improvement of concrete construction quality, but also increase the safety risks during project operation. Therefore, it is of great practical significance and application value to develop a whole-cycle monitoring device and method that can comprehensively, accurately, and continuously monitor the construction quality of mass concrete. SUMMARY

[0011] The technical problem to be solved by the present application is to provide a concrete quality three-level monitoring device and method, aiming to solve the specific technical problems of discontinuous monitoring process, missing key parameter monitoring, insufficient feedback control mechanism and incomplete whole-cycle monitoring in the field of mass concrete construction quality control. In particular, for mass concrete structures such as high-cold high-altitude hydropower stations and bridge piers, the existing technology often cannot fully cover the whole life cycle quality monitoring requirements from concrete pouring to water cooling and then to structural stability.

[0012] The present application provides a concrete quality three-level monitoring device to overcome the limitations of fragmented monitoring system, incomplete parameter monitoring and untimely feedback control in the prior art, thereby systematically improving the recognizability, controllability and traceability of concrete construction quality.

[0013] To achieve the above-mentioned goal, the present application adopts the following technical solutions: A concrete quality three-level monitoring device is constructed, specifically, the device is a three-level monitoring system composed of a "pouring layer-cooling layer-structure layer".

[0014] 1. Pouring layer monitoring module: set in the concrete pouring site, containing an array of temperature and humidity sensors and a flow rate sensor, which monitors the temperature, humidity and flow rate of the concrete in real time during pouring. The data acquisition unit integrates the sensor signals, performs preliminary processing and transmits them to the central controller, ensuring that the concrete enters the warehouse in a suitable state and speed, reducing the risk of segregation.

[0015] 2. Cooling layer monitoring module: deployed in the cooling water pipe network system inside or on the surface of the concrete structure, containing a flow meter, a temperature sensor group and a pressure sensor, which monitors the flow rate, temperature and water pressure of the cooling water in real time. The data acquisition unit integrates and transmits these parameters to the central controller to evaluate the cooling efficiency and achieve dynamic control.

[0016] 3. Structure layer monitoring module: embedded in the interior of the concrete structure, containing a distributed temperature sensor group and a strain sensor group, which monitors the internal temperature field distribution and internal strain of the concrete during hardening and stabilization in real time. The data acquisition unit is responsible for collecting and processing these data and uploading them to the central controller for further analysis.

[0017] 4. Central controller: as the core of the system, it establishes communication connection with the above three monitoring modules, is responsible for receiving, storing and processing real-time data, analyzes according to preset threshold and algorithm model, issues warning information, and outputs control instructions to related executing mechanism, forming a closed-loop quality management chain of "monitoring-analysis-warning-control".

[0018] The present application also provides a concrete quality three-level monitoring method based on the above-mentioned device, the specific steps are as follows: 1. Pouring layer monitoring steps: Step 1.1, arranging a temperature and humidity sensor array and a flow rate sensor at a concrete pouring site to collect real-time temperature, humidity and flow rate data of the concrete; Step 1.2, the data acquisition unit performs preliminary processing on the sensor signals and transmits them to the central controller; Step 1.3, the central controller analyzes the received data in real time according to the preset threshold to determine whether the concrete state is suitable for storage, and issues a warning message if there is an abnormality.

[0019] 2. Cooling layer monitoring steps: Step 2.1, arranging flow meters, temperature sensor groups and pressure sensors in the cooling water pipe network system inside or on the surface of the concrete structure to collect real-time flow, temperature and water pressure data of the cooling water; Step 2.2, the data acquisition unit integrates and transmits these parameters to the central controller; Step 2.3, the central controller evaluates the cooling efficiency according to the real-time data and compares it with the preset threshold, and outputs control instructions to the relevant executing agencies if adjustment is needed to achieve dynamic control.

[0020] 3. Structure layer monitoring steps: Step 3.1, embedding distributed temperature sensor groups and strain sensor groups inside the concrete structure to collect real-time internal temperature field distribution and internal strain data of the concrete during the hardening and stabilization stages; Step 3.2, the data acquisition unit collects and processes these data and uploads them to the central controller; Step 3.3, the central controller analyzes the received data for a long time and continuously to evaluate the long-term performance and safety of the concrete structure, and issues a warning message if there is a potential risk.

[0021] The concrete quality three-level monitoring device and method provided by the application has the following beneficial effects: 1. The application effectively solves the specific technical problems existing in the field of mass concrete construction quality control, such as discontinuous monitoring process, missing key parameter monitoring, insufficient feedback control mechanism and incomplete whole-cycle monitoring, overcomes the limitations of the existing monitoring system, such as fragmentation, incomplete parameter monitoring and untimely feedback control, and systematically improves the recognizability, controllability and traceability of concrete construction quality.

[0022] 2. The application realizes comprehensive, accurate and continuous monitoring of the whole-cycle core parameters of concrete quality from storage to stable state, solves the data island phenomenon existing in the existing monitoring method, realizes data integration and sharing, and ensures the integrity and consistency of the monitoring data.

[0023] 3、The present application effectively reduces the risk of concrete segregation by real-time monitoring of the temperature, humidity and flow rate of the incoming concrete at the pouring layer, ensuring initial uniformity and improving construction quality, laying a good foundation for subsequent construction.

[0024] 4、During the monitoring process at the pouring layer, the present application can timely detect abnormal conditions during the concrete pouring process, such as excessively high temperature, insufficient humidity or abnormal flow rate, and thus quickly take measures to adjust and avoid potential quality problems.

[0025] 5、The present application precisely monitors the water flow parameters at the cooling layer, ensuring effective implementation of temperature control measures, using dynamic control technology to adjust the cooling water flow according to real-time monitoring data, improving cooling efficiency, solving the problem of control lag, and effectively preventing temperature cracks.

[0026] 6、The present application can adjust the cooling intensity in real time according to the internal temperature changes of the concrete by dynamically adjusting the cooling water flow at the cooling layer, avoiding excessive cooling or insufficient cooling, and improving the uniformity and stability of the cooling effect.

[0027] 7、The present application long-term and continuously monitors the internal state of the concrete at the structural layer, directly reflecting the real response and long-term performance of the concrete interior, and sets up a long-term monitoring mechanism to continuously evaluate the long-term performance and safety of the concrete structure, providing a reliable basis for structural maintenance.

[0028] 8、During the monitoring process at the structural layer, the present application can timely detect potential stress concentration areas and temperature anomalies by long-term monitoring of the strain and temperature changes in the concrete interior, providing precise guidance for structural reinforcement and repair.

[0029] 9、The present application integrates the data aggregation, fusion analysis, intelligent early warning and closed-loop control through central intelligent control, integrating scattered monitoring points into an organic whole, significantly improving the controllability and traceability of concrete construction quality, and realizing intelligent management.

[0030] 10、The central intelligent control system of the present application has strong data processing and analysis capabilities, can process a large amount of monitoring data in real time, and can perform early warning and control through intelligent algorithms, greatly improving the monitoring efficiency and accuracy.

[0031] 11、The present application effectively prevents concrete cracking, solves the cracking problem caused by temperature stress, shrinkage stress and other factors in mass concrete construction, improves engineering quality and safety, and prolongs the service life of the structure.

[0032] 12、The application provides valuable improvement suggestions for subsequent concrete construction. Through long-term accumulation and analysis of monitoring data, potential problems and improvement space in the construction process can be found, promoting the continuous optimization and improvement of construction technology. BRIEF DESCRIPTION OF DRAWINGS

[0033] The technical solutions of the application will be further described below with reference to the accompanying drawings and embodiments: Figure 1 Technical flowchart for the pouring layer monitoring module of the application; Figure 2 Technical flowchart for the cooling layer monitoring module of the application; Figure 3 Technical flowchart for the structural layer monitoring module of the application; Figure 4 Technical flowchart for the work of the central controller of the application. DETAILED DESCRIPTION

[0034] The technical solutions of the application will be further described below with reference to the accompanying drawings and embodiments: Embodiment 1 The embodiment provides a three-level concrete quality monitoring device. The device realizes comprehensive, accurate and continuous monitoring of the construction quality of mass concrete by constructing a three-level monitoring system of “pouring layer-cooling layer-structural layer”.

[0035] 1. Pouring layer monitoring module implementation (1) Sensor arrangement: In the concrete pouring site, an array of temperature and humidity sensors and a flow rate sensor are arranged. The array of temperature and humidity sensors is arranged in a multi-point manner to ensure comprehensive coverage of the pouring area and real-time monitoring of the temperature and humidity of the concrete. The flow rate sensor is installed on the concrete conveying pipeline to monitor the flow rate of the concrete in real time.

[0036] (2) Data acquisition and processing: The pouring layer data acquisition unit adopts a high-performance microprocessor, integrates sensor signals, performs preliminary processing (such as filtering, amplification, etc.), and transmits the processed data to the central controller through a wireless communication module.

[0037] (3) Central controller integration: The central controller adopts an industrial computer with powerful data processing and storage capabilities. It receives data from the pouring layer monitoring module, performs real-time analysis according to preset thresholds, and determines whether the concrete state is suitable for storage. If there is an anomaly, such as excessively high temperature or excessively fast flow rate, the central controller will issue a warning message and notify the on-site workers through a display screen or a mobile phone APP (Application).

[0038] 2. Cooling layer monitoring module implementation (1) Sensor and actuator arrangement: In the cooling water pipe network system inside or on the surface of the concrete structure, flow meters, temperature sensor groups, and pressure sensors are arranged. Flow meters are used to monitor the flow of cooling water in real time, temperature sensor groups are used to monitor the inlet and outlet temperatures of cooling water, and pressure sensors are used to monitor the water pressure in the cooling water pipe. At the same time, electric regulating valves are installed on the cooling water pipe as actuators to adjust the flow of cooling water according to the instructions of the central controller.

[0039] (2) Data acquisition and transmission: The cooling layer data acquisition unit also uses high-performance microprocessors to integrate the signals of flow meters, temperature sensor groups, and pressure sensors and perform preliminary processing. The processed data is transmitted to the central controller through wired or wireless communication.

[0040] (3) Dynamic regulation and control: The central controller receives data from the cooling layer monitoring module and evaluates the cooling efficiency based on real-time data. If the cooling efficiency is insufficient, such as if the temperature difference between the inlet and outlet is too small or the flow is too low, the central controller will output control instructions to the electric regulating valve to increase the flow of cooling water, thereby achieving dynamic regulation and control.

[0041] 3. Structure layer monitoring module implementation (1) Sensor arrangement: In the interior of the concrete structure, distributed temperature sensor groups and strain sensor groups are embedded by drilling and embedding. Distributed temperature sensor groups can monitor the temperature field distribution inside the concrete in real time, and strain sensor groups are used to monitor the strain inside the concrete.

[0042] (2) Data acquisition and long-term monitoring: The structure layer data acquisition unit is responsible for collecting and processing data from distributed temperature sensor groups and strain sensor groups and uploading data to the central controller through a wireless communication module. The central controller analyzes the received data continuously and evaluates the long-term performance and safety of the concrete structure.

[0043] (3) Early warning and feedback: If the central controller analyzes and finds potential risks inside the concrete, such as excessive temperature stress or abnormal strain, it will issue a warning message and notify the on-site staff through a display screen or a mobile phone APP. At the same time, the central controller can also provide feedback to the design unit or the construction unit, providing a reference for subsequent concrete construction.

[0044] Example 2 In another preferred embodiment, based on the above-mentioned embodiment 1, this embodiment provides a monitoring method based on a three-level monitoring device for concrete quality, which realizes comprehensive control of concrete construction quality by monitoring and analyzing various parameters of concrete during the pouring, cooling, and stabilizing stages in real time.

[0045] 1. Pouring layer monitoring step implementation Step 1.1, data collection: in the concrete pouring site, the temperature, humidity and flow rate data of the concrete are collected in real time through the temperature and humidity sensor array and flow rate sensor; Step 1.2, data analysis and early warning: after the pouring layer data collection unit preliminarily processes the sensor signals, it transmits them to the central controller. The central controller analyzes the received data in real time according to the preset threshold to determine whether the concrete state is suitable for storage. If there is an anomaly, such as excessively high temperature or excessively fast flow rate, the central controller will issue a warning message.

[0046] 2. Cooling layer monitoring step implementation Step 2.1, data collection and transmission: in the cooling water pipe network system inside or on the surface of the concrete structure, the flow rate, temperature and water pressure data of the cooling water are collected in real time through the flow meter, temperature sensor group and pressure sensor, and transmitted to the central controller; Step 2.2, dynamic regulation: the central controller evaluates the cooling efficiency according to the real-time data and compares it with the preset threshold. If it needs to adjust the flow rate of the cooling water, the central controller will output a regulation instruction to the electric regulating valve to achieve dynamic regulation; 3. Structure layer monitoring step implementation Step 3.1, long-term monitoring and data analysis: inside the concrete structure, the internal temperature field distribution and internal strain condition data of the concrete during the hardening and stabilization stages are collected in real time through the distributed temperature sensor group and strain sensor group, and uploaded to the central controller. The central controller analyzes the received data continuously and for a long time to evaluate the long-term performance and safety of the concrete structure; Step 3.2, early warning and feedback processing: if the central controller analyzes and finds potential risks in the concrete interior, it will issue a warning message and notify the on-site workers through the display screen or mobile phone APP, etc. At the same time, the central controller can also feed back the analysis results to the design unit or construction unit to provide improvement suggestions for subsequent concrete construction.

[0047] Example 3 In another preferred embodiment, based on the above-mentioned example 1, the present embodiment provides a three-level monitoring device for concrete quality, which is suitable for the three-level monitoring device for mass concrete construction of high-cold and high-altitude hydropower station dams.

[0048] This embodiment is designed for the scenario of mass concrete construction of high-cold and high-altitude hydropower station dams. In this scenario, concrete construction faces problems such as low temperature, large diurnal temperature difference, easy accumulation of concrete hydration heat and difficulty in heat dissipation, etc. Precise monitoring is needed to ensure construction quality. The specific composition and deployment of the device are as follows: (I) Overall architecture The device comprises a pouring layer monitoring module, a cooling layer monitoring module, a structural layer monitoring module and a central controller, each module is in communication connection with the central controller through an industrial Ethernet (wired) + 4G wireless network (backup), ensuring stable data transmission in complex construction environment, the central controller is deployed in a dam construction monitoring center, equipped with a 15-inch touch display screen and an audible and visual alarm device, which can display data in real time and trigger early warning.

[0049] (II) Specific composition and deployment of each module 1. Pouring layer monitoring module (1) Temperature and humidity sensor array: PT1000 high-precision platinum resistance temperature sensor (measurement range -50℃~200℃, precision ±0.1℃) and high-frequency capacitive humidity sensor (measurement range 0%~100%RH, precision ±2%RH) are selected, each group of array contains 3 temperature sensors and 2 humidity sensors, which are fixed on a steel support below the discharge port of the concrete pump truck, the support is 1.2m away from the discharge port, the sensor probe is inclined at 45° towards the falling concrete flow, ensuring that the distance to the concrete flow is controlled at 5cm~8cm, and the temperature and humidity of the concrete entering the warehouse are captured in real time.

[0050] (2) Flow rate sensor: non-contact radar flowmeter (measurement range 0.1m / s~5m / s, precision ±0.01m / s) is used, which is installed on the side wall of the chute at the end of the pump truck distribution rod, 0.8m away from the chute outlet, the radar probe is perpendicular to the surface of the concrete in the chute, avoiding damage to the probe by splashing concrete, and a protective shell (made of 304 stainless steel, 3mm thick) is also provided to resist wind and sand in cold regions.

[0051] (3) Pouring layer data acquisition unit: industrial-grade data acquisition unit (model: Advantech ADAM-4000) is selected, which integrates signal conditioning circuit and can convert analog signals output by sensors into digital signals (sampling frequency 1 / s), the acquisition unit is installed in the distribution box near the pump truck (the distribution box has heat preservation function and is provided with heating fins to ensure that the working temperature is not lower than -20℃), and the data is transmitted to the central controller through industrial Ethernet.

[0052] 2. Cooling layer monitoring module (1) Flowmeter: electromagnetic flowmeter (model: Yokogawa AXF, measurement range 0.05m³ / h~100m³ / h, precision ±0.5%) is selected, which is installed on the main pipeline (pipe diameter DN100) and four key branch pipes (pipe diameter DN50) of the internal cooling water pipe of the dam concrete, the straight pipe sections before and after the flowmeter are 5 times and 3 times the pipe diameter respectively to ensure the measurement accuracy, and the sensor probe is made of 316L stainless steel to resist the alkaline corrosion of concrete.

[0053] (2) Temperature sensor group: Choose armored thermocouple temperature sensor (model: K type, measurement range -200℃~1300℃, accuracy ±0.3℃), install one at the inlet and outlet of each cooling water pipe circuit, the sensor probe is inserted into the pipeline for 5 cm, fully contacts with water flow, the wire uses high temperature resistant shielding wire to avoid electromagnetic interference, at the same time, two additional temperature measuring points are added near the dam water surface of two key cooling circuits to monitor the cooling effect of special areas.

[0054] (3) Pressure sensor: Choose diffusion silicon pressure transmitter (measurement range 0~1.6MPa, accuracy ±0.2%), install at the inlet of cooling water pipe main pipeline and after each branch pipe valve, the sensor interface uses screw connection (specification G1 / 2), matched with sealing gasket to prevent water leakage, the pressure signal is transmitted to the data acquisition unit through 4~20mA current signal.

[0055] (4) Cooling layer data acquisition unit: Use distributed data acquisition module (model: Siemens S7-1200), each module can access 8 channel flowmeter signals, 16 channel temperature sensor signals and 8 channel pressure sensor signals, the module is installed in the monitoring room near the dam body (the monitoring room is equipped with constant temperature control system, the temperature is maintained at 15℃~25℃), communicates with the central controller through industrial Ethernet, and has local data storage function (storage capacity 16GB, can save 3 months of data) to prevent data loss.

[0056] 3. Structural layer monitoring module (1) Distributed temperature sensor group: Choose fiber optic grating temperature sensor (measurement range -50℃~300℃, accuracy ±0.5℃), arrange according to the space grid of 2m×2m×1.5m, pre-bury into different depths (5 depth layers from the surface of the dam body to the center, 0.5m, 2m, 5m, 8m, 12m respectively) during dam concrete pouring, the sensor fiber uses single mode fiber (diameter 0.9mm), externally wrapped with PE protective sleeve (thickness 2mm), the fiber outgoing end is connected to the fiber distribution frame to avoid damage during construction.

[0057] (2) Strain sensor group: Choose vibrating wire strain gauge (measurement range -3000με~3000με, accuracy ±8με), cooperatively arranged with temperature sensor, mainly installed at dam foundation restraint area (within 1m from dam foundation), hole periphery (such as 50cm area around diversion hole and grouting hole) and dam body horizontal construction joint, each strain gauge is matched with one temperature compensation sensor to eliminate the influence of temperature change on strain measurement, the strain gauge is fixed on the reinforcement through pre-burying base to ensure synchronous deformation with concrete.

[0058] (3) Structural layer data acquisition unit: Optical fiber demodulator (model: Keyence IV2 series, demodulation frequency 1 Hz) and vibrating wire data acquisition instrument (model: Jingjiang Zhongtai JTM-300) are used. The optical fiber demodulator is used to collect the data of the optical fiber grating temperature sensor, and the vibrating wire data acquisition instrument is used to collect the data of the strain gauge. Both are installed in the monitoring room. The calculated temperature and strain data are transmitted to the central controller through Ethernet. At the same time, the data acquisition unit has edge computing function, which can locally filter abnormal data (such as values exceeding the range) and mark, and only upload valid data.

[0059] 4. Central controller An industrial control computer (model: Yenchuan IPC-610) is selected, which is configured with Intel Core i7 processor, 16GB memory, 1TB solid state disk, installed with Windows Server 2019 operating system and self-developed monitoring software. The software has the following functions: (1) Data storage: Establish SQL Server database, store each module data at 1 minute interval, can save 5 years data, support data query, export (format Excel, CSV (Comma-Separated Values, character separation value)).

[0060] (2) Multi-parameter fusion analysis: Built-in temperature control curve (set according to dam concrete strength grade C30, maximum temperature rise not more than 70℃, cooling rate not more than 2℃ / d) and stress prediction model (based on finite element algorithm), can compare the temperature of pouring layer and structural layer, evaluate the influence of warehouse temperature on internal temperature rise; Combined with cooling layer flow and structural layer temperature, calculate cooling efficiency (such as temperature drop rate corresponding to each 1m³ / h flow); Based on structural layer temperature and strain, predict temperature stress and evaluate cracking risk.

[0061] (3) Intelligent early warning: Set the threshold of each level parameter (such as pouring layer temperature exceeding 5℃~30℃ range, flow rate exceeding 0.5m / s~2m / s range, cooling layer flow less than 1m³ / h or more than 5m³ / h, structural layer temperature gradient more than 2℃ / m, tensile strain more than 150με), once the data is abnormal, immediately trigger sound and light alarm (alarm sound intensity ≥80dB, alarm light is red flashing), at the same time, send early warning information to 5 key personnel such as project manager, technical director through SMS (with the help of 4G SMS module) and APP (developed supporting "dam concrete monitoring APP", supporting Android and iOS systems), the information includes abnormal time (accurate to seconds), location (such as "2# pump truck discharge port", "3# cooling loop", "dam body 5m depth"), parameter name and over standard value (such as "temperature 35℃, over standard 5℃").

[0062] (4) Closed-loop control: output 4~20mA control signal to relevant executing agencies, such as adjusting the pumping pressure of the pump truck according to the pouring layer flow rate (lower the pressure when the flow rate is too fast, and increase the pressure when the flow rate is too slow); according to the cooling layer data and the structural layer temperature, control the opening of the cooling water pipe electric regulating valve (model: Siemens VVF47, adjustment accuracy ±1%) to realize dynamic adjustment of flow (such as increasing the valve opening and increasing the flow when the structural layer temperature is higher than the threshold); in the case of extreme risk (such as the structural layer tensile strain exceeding 200με), output instructions to suspend the pouring equipment (such as pump truck, distributor), and start the standby cooling system (additional 2 cooling circuits).

[0063] (5) Data visualization and reporting: real-time display of module data on the touch screen (in the form of numbers, curves, and column charts), such as pouring layer temperature time curve, cooling layer circuit flow comparison column chart, structural layer temperature field cloud chart (using color gradient to represent temperature, red for high temperature area, blue for low temperature area) and strain distribution chart; quality reports can be automatically generated daily, weekly, and monthly, including monitoring data statistics at each stage (such as average temperature, maximum flow rate, average flow), abnormal records and processing conditions, quality evaluation conclusion (such as "this week's concrete into the warehouse quality is qualified, cooling effect is good, no cracking risk"), supporting printing and electronic archiving.

[0064] Embodiment 4 In another preferred embodiment, based on the above-mentioned embodiments 2 and 3, the present embodiment provides a three-level monitoring method for concrete quality, which is suitable for the three-level monitoring method for large volume concrete construction of hydropower station dam in high-cold and high-altitude areas.

[0065] The present embodiment is applied to the above-mentioned monitoring of large volume concrete construction of hydropower station dam, the construction concrete strength grade is C30, the single pouring volume is 2000m³, the pouring time is from 8:00 on X month X day in 202X to 12:00 the next day, the cooling period is 28 days after pouring is completed, and the structural stability monitoring period is 1 year after cooling is completed. The specific monitoring steps are as follows: (I) Preliminary preparation 1. One week before construction, complete installation and debugging of each module: check whether the installation positions of the temperature and humidity sensor array and the flow rate sensor meet the requirements, test whether the sensor output signals are normal after power-on, check the accuracy of the cooling layer flow meter, temperature sensor group, and pressure sensor (calibrated using standard equipment, such as using a standard flow generator to calibrate the flow meter and using a constant temperature tank to calibrate the temperature sensor), confirm the pre-buried positions of the structural layer sensors (fix the sensors according to the pre-set grid after steel reinforcement is completed according to the dam construction drawings, ensuring that the position deviation does not exceed 5 cm), test the data acquisition function of the optical fiber demodulator and the vibrating wire data acquisition instrument, debug the communication between the central controller and each module to ensure normal data transmission (continuous testing for 24 hours, data loss rate ≤0.1%), and input the pre-set threshold values and algorithm model parameters.

[0066] 2. Train construction personnel, including the working principle of the monitoring device, the pre-warning information processing flow (such as after receiving the pre-warning information, the technical person in charge needs to arrive at the site within 10 minutes for verification), and the operation of the actuator control (such as the method of manually adjusting the opening degree of the electric regulating valve), to ensure that personnel can correctly cooperate with the monitoring work.

[0067] (II) Pouring layer monitoring (step 1) 1. Start monitoring: at 8:00 on X day of X month of 202X, start the temperature and humidity sensor array, flow rate sensor, and pouring layer data acquisition unit of the pouring layer monitoring module, and set the data sampling frequency to 1 time per second.

[0068] 2. Data acquisition and transmission: the temperature and humidity sensor array monitors the temperature and humidity of the incoming concrete in real time, such as monitoring the temperature of 22°C and the humidity of 65% at 8:30; the flow rate sensor monitors the flow rate, such as the flow rate of 1.2 m / s at 8:45; after the pouring layer data acquisition unit processes these data (such as converting analog signals to digital signals), it is transmitted to the central controller through industrial Ethernet with a transmission delay of ≤1 second.

[0069] 3. Data processing and response: after the central controller receives the data, it compares with the pre-set threshold values (temperature 5°C~30°C, humidity 50%~80%, flow rate 0.5 m / s~2 m / s). The above data are all within the normal range and do not trigger the pre-warning; at 9:10, the temperature of the concrete at the discharge outlet of pump truck No. 2 is monitored to be 32°C, which exceeds the threshold value (exceeding 2°C), the central controller immediately triggers the sound and light alarm and pushes the pre-warning information to the key personnel; after receiving the information, the technical person in charge arrives at the site at 9:15 and finds that the preheating temperature of the aggregate at the concrete mixing plant is too high, adjusts the aggregate preheating system immediately to reduce the preheating temperature, and at 9:30 the temperature of the pouring layer is reduced to 28°C, returning to normal, the central controller stops the alarm, and records the abnormal processing process (including the cause, measures, and recovery time).

[0070] 4. Dynamic regulation: At 10:00, the flow rate of 1# pump truck is monitored to be 0.4 m / s, which is lower than the threshold value (0.5 m / s). The central controller outputs a signal to the pump truck control system to increase the pumping pressure from 15 MPa to 18 MPa. At 10:05, the flow rate rises to 0.6 m / s, returning to the normal range. At 14:30, the flow rate of 3# pump truck is 2.2 m / s, which exceeds the threshold value. The central controller reduces the pumping pressure to 12 MPa. At 14:35, the flow rate decreases to 1.8 m / s, meeting the requirements.

[0071] (Three) Cooling layer monitoring (step 2) 1. Start monitoring: After the concrete pouring is completed (202X year X month X day 12:00), immediately start the flow meter, temperature sensor group, pressure sensor and cooling layer data acquisition unit of the cooling layer monitoring module. The sampling frequency is 1 time / minute.

[0072] 2. Data acquisition and transmission: The flow meter monitors the flow rate of each cooling circuit. For example, at 12:30, the main pipe flow rate is 3 m³ / h and the 3# branch pipe flow rate is 1.5 m³ / h. The temperature sensor group monitors the inlet water temperature (e.g. 15°C) and outlet water temperature (e.g. 22°C), and calculates the temperature difference between inlet and outlet water to be 7°C. The pressure sensor monitors the main pipe pressure to be 0.8 MPa and the branch pipe pressure to be 0.6 MPa~0.7 MPa. The cooling layer data acquisition unit transmits the processed data to the central controller.

[0073] 3. Data processing and response: The central controller compares the cooling layer data with the preset threshold values (flow rate 1 m³ / h~5 m³ / h, temperature difference between inlet and outlet water 3°C~10°C, pressure 0.5 MPa~1.2 MPa). The above data is normal. At 8:00 the next day, the central controller monitors that the flow rate of 5# cooling circuit is 0.8 m³ / h, which is lower than the threshold value, and the pressure is 1.3 MPa, which is higher than the threshold value. The central controller judges that it may be water pipe blockage and immediately triggers an early warning and pushes information. Maintenance personnel arrive at the scene at 8:10 and find that the filter screen is blocked. After cleaning the filter screen, the flow rate returns to 2 m³ / h and the pressure decreases to 0.9 MPa at 8:20, returning to normal.

[0074] 4. Dynamic regulation: On the third day after pouring (X month X+2), the structure layer monitoring module 2 monitors that the temperature at the depth of 5 m of the dam body is 65°C, which is close to the threshold value (70°C). The central controller combines the cooling layer data (current 3# cooling circuit flow rate is 2 m³ / h, inlet and outlet water temperature difference is 5°C) and calculates that the flow rate needs to be increased to 3 m³ / h to control the temperature rise. Immediately output a signal to the 3# circuit electric regulating valve to increase the opening degree from 50% to 75%. After 1 hour, the flow rate rises to 3 m³ / h. On the fourth day (X month X+3), the structure layer temperature decreases to 60°C, meeting the requirements.

[0075] (Four) Structural layer monitoring (step 3) 1. Pre-embedding and starting: During the concrete pouring and vibrating process (X month X day 10:00 to the next day 10:00), the distributed temperature sensor group and strain sensor group of the structural layer are pre-embedded into the dam body according to the preset grid, ensuring that the sensors are tightly combined with the concrete without gaps; 12 hours after pouring (after the concrete enters the initial setting stage, X month X+1 day 20:00), the sensors of the structural layer monitoring module and the structural layer data acquisition unit are started, and the sampling frequency is set to 1 time / 10 minutes (during the cooling period) and 1 time / 1 hour (during the stable monitoring period).

[0076] 2. Data acquisition and transmission: The distributed temperature sensor group monitors the internal temperature field distribution in real time, such as X month X+5 day 10:00, the surface (0.5m depth) temperature of the dam body is 18℃, the center (12m depth) temperature is 68℃, and the temperature gradient is 1.2℃ / m; The strain sensor group monitors the internal strain, such as X month X+10 day 8:00, the strain of the dam foundation constraint area is 120με (compressive strain), and the strain of the hole periphery is 80με (tensile strain); After the structural layer data acquisition unit solves the data, it is transmitted to the central controller through Ethernet, and at the same time, local data screening is carried out to eliminate abnormal values (such as instantaneous strain out of range data caused by construction vibration).

[0077] 3. Data processing and response: The central controller compares the structural layer data with the preset threshold (temperature gradient≤2℃ / m, tensile strain≤150με), and the above data is normal; At 14:00 on X month X+15 day, it is monitored that the temperature gradient at the depth of 8m of the dam body is 2.5℃ / m, which exceeds the threshold, the central controller combines the cooling layer data (the flow of 4# cooling circuit corresponding to this area is 2.5m³ / h), judges that the cooling is uneven, and immediately triggers the early warning; After the technical team analyzes the data at 14:15, the opening of the electric regulating valve of 4# circuit is adjusted, the flow is increased from 2.5m³ / h to 3.5m³ / h, and at the same time, a thermal insulation blanket (thickness 5cm) is covered on the surface of this area, at 14:30, the temperature gradient decreases to 2℃ / m, and returns to normal.

[0078] 4. Long-term monitoring: After the cooling period (28 days) ends, enter the structural stability monitoring period (1 year), continue to monitor the temperature and strain of the structural layer, such as X month X+90 day, the internal temperature of the dam body is stable at 15℃~20℃, the strain is stable at 50με~100με, there is no obvious change, the central controller evaluates that the long-term stability of the structure is good, generates a monthly report, and records the monitoring results.

[0079] (Five) Central controller comprehensive processing (step 4) 1. Whole-process data storage: The central controller receives and stores all data of the three modules in real time, such as the temperature and flow rate data of the pouring layer at 1-minute intervals, the flow, temperature, and pressure data of the cooling layer at 1-minute intervals, and the temperature and strain data of the structural layer at 10-minute (cooling period) or 1-hour (stabilization period) intervals, ensuring data traceability. For example, when checking the cooling effect on X+3 days later, the flow variation curve and the structural layer temperature variation curve of each cooling circuit on that day can be queried.

[0080] 2. Multi-parameter fusion analysis: During the entire monitoring process, the central controller continuously performs multi-parameter fusion analysis, such as comparing the pouring layer inlet temperature (average 25℃) with the internal maximum temperature of the structural layer (68℃), evaluating that for every 1℃ increase in the inlet temperature, the internal maximum temperature increases by 1.2℃; combining the total flow of the cooling layer (average 3m³ / h) with the structural layer temperature drop rate (average 1.5℃ / d), calculating the cooling efficiency as 0.5℃ / (d·m³ / h); and based on the structural layer temperature and strain data, predicting the maximum temperature stress as 1.8MPa, which is lower than the concrete tensile strength (2.0MPa), indicating a low cracking risk.

[0081] 3. Report generation: Daily reports are generated daily, such as the daily report on X day showing "2000m³ of concrete was poured on that day, the pouring layer temperature was 22℃ on average, the flow rate was 1.1m / s on average, and there were no abnormalities; the cooling layer flow was normal, with an average of 2.8m³ / h; the initial temperature of the structural layer was 35℃ on average, and there were no abnormalities"; weekly reports are generated weekly, which statistically summarize the average, maximum, and minimum values of each parameter and the number of abnormalities (such as 2 pre-alarm occurrences this week, which have been timely handled); and monthly reports are generated monthly, which include quality evaluation conclusions and improvement suggestions (such as "the cooling effect is good this month, and it is suggested to pay attention to surface insulation of the dam body in the future to prevent temperature sudden drop").

[0082] Through the devices and methods of embodiments 3 and 4, three-level monitoring of the mass concrete of the hydropower station dam from pouring, water cooling to structural stability is achieved, effectively solving the temperature control problem in concrete construction in high-cold and high-altitude areas, ensuring the quality of concrete construction, and ensuring the safety and durability of the dam structure.

[0083] Embodiment 5 In another preferred embodiment, based on the above-mentioned embodiment 1, the present embodiment provides a three-level concrete quality monitoring device suitable for the three-level monitoring device for bridge pier and platform mass concrete construction.

[0084] This embodiment is designed for the bridge pier and platform mass concrete construction scene. The bridge pier and platform are the key load-bearing structures of the bridge, and the quality of the concrete directly affects the overall safety and durability of the bridge. In this scene, the pouring, cooling, and structural stability processes need to be strictly controlled. The specific composition and deployment of the device are as follows: (I) Overall architecture The device includes a pouring layer monitoring module, a cooling layer monitoring module, a structural layer monitoring module, and a central controller. Each module and the central controller are communicatively connected through industrial-grade Wi-Fi (Wireless Fidelity, mobile hotspot) (coverage radius 200 m) and wired Ethernet (backup) to ensure stable data transmission. The central controller is deployed in a temporary monitoring room at the bridge construction site, equipped with a 12-inch touch display screen and an audible and visual alarm device, which can present data in real time and issue warnings.

[0085] (II) Specific composition and deployment of each module 1. Pouring layer monitoring module, as shown in Figure 1 : (1) Temperature and humidity sensor array: high-precision digital temperature and humidity sensor (measurement range -10°C~50°C, temperature accuracy ±0.2°C, humidity accuracy ±3%RH) is selected. Each array contains 4 temperature sensors and 3 humidity sensors, installed on an adjustable bracket 1m below the discharge port of the concrete delivery pump, with the sensor probe facing the concrete flow and maintaining a distance of 3cm~6cm from the concrete flow, to monitor the temperature and humidity of the incoming concrete in real time , .

[0086] (2) Flow rate sensor: non-contact laser flowmeter (measurement range 0.2m / s~3m / s, accuracy ±0.02m / s) is used. It is installed on the side wall of the chute connected to the discharge port of the delivery pump, 1m away from the chute outlet. The laser probe is perpendicular to the concrete surface in the chute, monitoring the flow rate of the incoming concrete in real time , with a waterproof and dustproof protective cover to prevent concrete splashing and dust from affecting measurement.

[0087] (3) Pouring layer data acquisition unit: embedded data acquisition unit (model: STM32F4 series) is used, which integrates signal conditioning circuit and can convert sensor analog signal to digital signal (sampling frequency 2 times / second). The acquisition unit is installed in the distribution box near the delivery pump (the distribution box has dustproof and waterproof function, protection level IP65). The data is transmitted to the central controller through industrial-grade Wi-Fi.

[0088] 2. Cooling layer monitoring module, as shown in Figure 2 , arranged in the cooling water pipe network: (1) Flow meter: ultrasonic flow meter (measurement range 0.1m³ / h~8m³ / h, accuracy ±0.3%) is selected. It is installed on the main pipe (pipe diameter DN80) of the bridge pier cooling water pipe and 3 key branch pipes (pipe diameter DN40) to monitor the flow in real time ​The straight pipe sections before and after the flow meter are 4 times the pipe diameter and 2 times the pipe diameter, respectively, to ensure accurate measurement. The sensor probe is made of corrosion-resistant material and is suitable for cooling water environment.

[0089] (2) Temperature sensor group: PT100 platinum resistance temperature sensor (measuring range -20℃~100℃, accuracy ±0.1℃) is selected. One sensor is installed at the inlet and outlet of each cooling water pipe circuit to monitor the temperature of the inlet and outlet in real time. , The sensor probe is inserted 4cm into the pipe to ensure full contact with the water flow. The wire is a high-temperature shielded wire to avoid electromagnetic interference.

[0090] (3) Pressure sensor: A ceramic piezoresistive pressure transmitter (measurement range 0~1.2MPa, accuracy ±0.1%) is selected and installed at the inlet of the main cooling water pipe and after each branch valve to monitor the inlet water pressure P in real time. The sensor interface is a threaded connection (specification G3 / 8), and a matching sealing gasket is provided to prevent water leakage. The pressure signal is transmitted to the data acquisition unit through a 4~20mA current signal.

[0091] (4) Cooling layer data acquisition unit: A PLC data acquisition module (model: Siemens S7-1200) is adopted. Each module can connect to 6 flow meter signals, 12 temperature sensor signals and 6 pressure sensor signals. The module is installed in a monitoring box near the bridge pier (the monitoring box has sunshade and rain protection function). It communicates with the central controller through industrial-grade Wi-Fi and has local data storage function (storage capacity of 8GB, which can save 2 months of data) and analysis and processing function (calculation). ).

[0092] 3. Structural layer monitoring module, such as Figure 3 As shown: (1) Distributed temperature sensor group: Digital temperature sensors (model: DS18B20, measurement range -55℃~125℃, accuracy ±0.5℃) are selected and arranged in a spatial grid of 1.5m×1.5m×1m. They are pre-embedded at different depths (4 depth layers from the surface of the pier to the center, namely 0.5m, 1.5m, 3m and 4.5m) during the concrete pouring of the bridge piers and abutments to monitor the internal temperature in real time. The sensor leads are made of fold-resistant wires and are wrapped with a PVC (Polyvinyl chloride) protective sleeve (1.5mm thick). The lead ends are neatly arranged to avoid damage during construction.

[0093] (2) Strain sensor group: Fiber optic strain sensors (measurement range -1500με~1500με, accuracy ±5με) are selected and arranged in conjunction with temperature sensors to monitor internal strain in real time. , and are mainly installed in the constraint area (within 0.5 m from the bottom of the pier), the steel bar dense area, and the joint of the pier and the foundation. Each strain sensor is equipped with a temperature compensation sensor to eliminate the influence of temperature on strain measurement. The strain sensor is fixed on the steel bar through a special clamp to ensure synchronous deformation with the concrete.

[0094] (2) Structure layer data acquisition unit: optical fiber demodulator (model: MOI sm125) and multi-channel data acquisition instrument (model: NI cDAQ-9178) are used. The optical fiber demodulator collects data of the fiber bragg grating strain sensor, and the multi-channel data acquisition instrument collects data of the digital temperature sensor. Both are installed in the monitoring box and transmit the calculated temperature and strain data to the central controller through industrial Wi-Fi. The data acquisition unit has edge computing capability and can locally filter abnormal data (such as data beyond the range) and mark, uploading only valid data. (Compression).

[0095] 4. Central controller, as shown in Figure 4 . Industrial tablet computer (model: Jenei TPC-1251T) is selected, with Intel Core i5 processor, 8 GB memory, 512 GB solid state disk, Windows 10 IoT operating system and self-developed monitoring software installed. The software functions are as follows: (1) Data storage: SQLite database is established to store module data at 2-minute intervals, which can store data for 3 years, support data query and export (Excel and CSV formats).

[0096] (2) Multi-parameter fusion analysis: built-in bridge pier concrete temperature control curve (set according to concrete strength grade C40, maximum temperature rise not more than 65℃, cooling rate not more than 1.5℃ / d) and stress prediction model (based on elastic mechanics algorithm) can compare the temperature of pouring layer and structure layer, evaluate the influence of warehouse temperature on internal temperature rise; combined with cooling layer flow and structure layer temperature, calculate cooling efficiency; based on structure layer temperature and strain, predict temperature stress and evaluate cracking risk.

[0097] (3) Intelligent early warning: set threshold values for various parameters (such as pouring layer temperature exceeding the range of 10℃~35℃, flow rate exceeding the range of 0.3m / s~2.5m / s, cooling layer flow rate being lower than 0.5m³ / h or higher than 6m³ / h, structural layer temperature gradient exceeding 2.5℃ / m, and tensile strain exceeding 180με), when data is abnormal, immediately trigger sound and light alarm (alarm sound intensity ≥75dB, alarm light is red flashing), and at the same time, send early warning information to 4 key personnel such as project manager and technical supervisor through short message (with the help of 4G short message module) and APP (develop "Bridge Concrete Monitoring APP", supporting Android and iOS systems), the information includes abnormal time, location, parameter and over-standard value.

[0098] (4) Closed-loop control: output 4~20mA control signal to related execution mechanism, such as adjusting the pumping frequency of the delivery pump according to the pouring layer flow rate; controlling the opening of the cooling water pipe electric regulating valve (model: Shanwu AVP100, regulating accuracy ±1%) according to the cooling layer and structural layer data, and dynamically adjusting the flow rate; in the case of extreme risk (such as structural layer tensile strain exceeding 220με), output command to stop the delivery pump and start the standby cooling measures.

[0099] (5) Data visualization and reporting: real-time display of various module data (in the form of numbers, curves, and heat maps) on the touch screen, such as pouring layer temperature time curve, cooling layer flow rate comparison column chart, structural layer temperature field heat map and strain distribution map; automatically generate quality reports on a daily, weekly, and monthly basis, including data statistics, abnormal records and processing conditions, quality evaluation conclusions, supporting printing and electronic archiving.

[0100] Example 6 In another preferred embodiment, based on the above-mentioned examples 2 and 5, this embodiment provides a three-level monitoring method for concrete quality, which is suitable for three-level monitoring method for bridge pier and platform mass concrete construction.

[0101] This embodiment is applied to the above-mentioned monitoring of bridge pier and platform mass concrete construction, the construction concrete strength grade is C40, the single pouring volume is 1500m³, the pouring time is from 9:00 on 202X year X month X day to 14:00 the next day, the cooling period is 25 days after pouring is completed, and the structural stability monitoring period is 1 year after cooling is completed, and the specific monitoring steps are as follows: (I) Preliminary preparation 1. Complete installation and debugging of each module 5 days before construction: check the installation position of the pouring layer temperature and humidity sensor array and the flow rate sensor, test the signal after power on; check the accuracy of the cooling layer flow meter, temperature sensor group, and pressure sensor; confirm the pre-embedded position of the structural layer sensor and test the data acquisition function; debug the communication between the central controller and each module, and input the preset threshold value and algorithm model parameter.

[0102] 2. Train the construction personnel, including the working principle of the monitoring device, the early warning process, and the operation method of the actuator, to ensure that personnel can cooperate with the monitoring work.

[0103] (II) Pouring layer monitoring 1. Start monitoring: At 9:00 on X day of X month of 202X, turn on the temperature and humidity sensor array, flow rate sensor, and data acquisition unit of the pouring layer monitoring module, and set the data sampling frequency to 2 times per second.

[0104] 2. Data acquisition and transmission: The temperature and humidity sensor array monitors the temperature and humidity of the incoming concrete in real time. For example, at 9:30, the temperature is 28°C and the humidity is 70%. The flow rate sensor monitors the flow rate of the incoming concrete. For example, at 9:45, the flow rate is 1.5 m / s. After the data acquisition unit processes the data, it is transmitted to the central controller through industrial-grade Wi-Fi with a transmission delay of ≤2 seconds.

[0105] 3. Data processing and response: The central controller compares the data with the preset threshold value, and normal data does not trigger an early warning. At 10:10, the temperature of the concrete at the discharge port of 1# pump is monitored to be 38°C, which exceeds the threshold value (exceeding 3°C). The central controller immediately triggers an audible and visual alarm and pushes the early warning information. The technical person in charge arrives at the scene at 10:15 and finds that the aggregate temperature at the concrete mixing plant is too high. Adjust the aggregate cooling measures. At 10:30, the pouring layer temperature drops to 32°C, returning to normal. The central controller stops the alarm and records the abnormal handling process.

[0106] 4. Dynamic regulation: At 11:00, the flow rate is monitored to be 0.4 m / s, which is lower than the threshold value (0.3 m / s). The central controller outputs a signal to increase the pumping frequency of the delivery pump. At 11:05, the flow rate rises to 0.6 m / s, meeting the requirements.

[0107] (III) Cooling layer monitoring 1. Start monitoring: After the concrete is poured (at 14:00 on X day of X month of 202X), immediately turn on the flow meter, temperature sensor group, pressure sensor, and data acquisition unit of the cooling layer monitoring module, with a sampling frequency of 1 time per minute.

[0108] 2. Data acquisition and transmission: The flow meter monitors the flow rate of each cooling circuit. For example, at 14:30, the main pipe flow rate is 2.5 m³ / h and the 2# branch pipe flow rate is 1.2 m³ / h. The temperature sensor group monitors the inlet water temperature of 18°C and the outlet water temperature of 25°C, with a temperature difference of 7°C. The pressure sensor monitors the main pipe pressure of 0.7 MPa and the branch pipe pressure of 0.5 MPa~0.6 MPa. The data acquisition unit processes the data and transmits it to the central controller.

[0109] 3、Data processing and response: The central controller compares the data with the preset threshold, and normal data does not trigger an early warning. At 9:00 the next day, the monitoring found that the flow of the 3# cooling circuit was 0.4m³ / h, lower than the threshold, and the pressure was 1.3MPa, higher than the threshold. The central controller judged that the water pipe was blocked, triggered an early warning and pushed information. The maintenance personnel arrived at the scene at 9:10, cleaned the filter screen, and the flow returned to 1.5m³ / h and the pressure dropped to 0.8MPa at 9:20, returning to normal.

[0110] 4、Dynamic regulation: On the 4th day after pouring (X+3, X month), the structural layer monitoring module monitored that the temperature at the depth of 3m of the pier was 62℃, close to the threshold (65℃), and the central controller combined the cooling layer data (current 2# cooling circuit flow is 2m³ / h, water temperature difference is 5℃) to calculate that the flow needs to be increased to 3m³ / h, and the output signal controls the cooling water pipe electric regulating valve opening degree from 50% to 70%, the flow increases to 3m³ / h after 1 hour, and the structural layer temperature decreases to 58℃ on the 5th day (X+4, X month), meeting the requirements.

[0111] (Four) Structural layer monitoring 1、Pre-buried and started: During the concrete pouring and vibrating process (9:00 on X month X day to 10:00 the next day), the distributed temperature sensor group and strain sensor group of the structural layer are pre-buried into the pier according to the preset grid, ensuring that the sensors are tightly combined with the concrete; 10 hours after pouring (18:00 on X+1 day, X month), start the sensors and data acquisition unit of the structural layer monitoring module, set the sampling frequency to 1 time / 8 minutes (during the cooling period) and 1 time / 1.5 hours (during the stable monitoring period).

[0112] 2、Data acquisition and transmission: The distributed temperature sensor group monitors the internal temperature field distribution in real time, such as 10:00 on X+6, X month, the temperature of the pier surface (0.5m depth) is 20℃, the temperature of the center (4.5m depth) is 60℃, and the temperature gradient is 1.1℃ / m; The strain sensor group monitors the internal strain, such as 8:00 on X+11, X month, the strain of the pier bottom constraint area is 130με (compressive strain), and the strain of the steel bar dense area is 90με (tensile strain); After the data acquisition unit solves the data, it is transmitted to the central controller through industrial Wi-Fi, and the local abnormal values are screened at the same time.

[0113] 3. Data processing and response: The central controller compares the data with the preset threshold value, and normal data does not trigger an early warning. On X+16, 15:00, the temperature gradient at the depth of 4m of the pier is 2.8℃ / m, which exceeds the threshold value. The central controller combines the cooling layer data (the corresponding 3# cooling circuit flow in this area is 2.2m³ / h) to determine that the cooling is uneven, triggering an early warning. The technical team analyzes the data at 15:15 and adjusts the opening of the 3# electric regulating valve to increase the flow from 2.2m³ / h to 3.2m³ / h, and covers the surface of the area with thermal insulation materials. At 15:30, the temperature gradient decreases to 2.3℃ / m, and returns to normal.

[0114] 4. Long-term monitoring: After the cooling period (25 days) is over, the structure enters the stable monitoring period (1 year), and the structure layer temperature and strain are continuously monitored. On X+80, the internal temperature of the pier is stable at 18℃~23℃, and the strain is stable at 60με~110με, with no obvious changes. The central controller evaluates the long-term stability of the structure as good, and generates a monthly report.

[0115] (Five) Central controller comprehensive processing 1. Full data storage: The central controller receives and stores all data of the three modules in real time, ensuring data traceability. For example, if the cooling effect on X+4 is to be checked later, the flow variation curve and the structure layer temperature variation curve of each cooling circuit on that day can be queried.

[0116] 2. Multi-parameter fusion analysis: During the entire monitoring process, the central controller continuously performs multi-parameter fusion analysis. For example, by comparing the pouring layer temperature (average 26℃) with the internal maximum temperature of the structure layer (62℃), it is evaluated that for every 1℃ increase in the pouring layer temperature, the internal maximum temperature increases by 1.3℃. Combined with the total cooling layer flow (average 2.8m³ / h) and the structure layer temperature drop rate (average 1.3℃ / d), the cooling efficiency is calculated to be 0.46℃ / (d·m³ / h). Based on the structure layer temperature and strain, the maximum temperature stress is predicted to be 1.7MPa, which is lower than the tensile strength of concrete (2.3MPa), and the cracking risk is relatively low.

[0117] 3. Report generation: Daily reports are generated daily, weekly reports are generated weekly, and monthly reports are generated monthly, containing data statistics, abnormal processing, quality evaluation, etc., providing a basis for engineering quality evaluation and subsequent improvement.

[0118] Through the devices and methods of embodiments 5 and 6, three-level monitoring of the bridge pier mass concrete from pouring, water cooling to structure stability is realized, the construction quality is effectively controlled, and no temperature cracks and other quality problems occur, ensuring the safety and durability of the bridge pier structure.

[0119] In the preferred scheme, the pouring layer monitoring module comprises a temperature and humidity sensor array, a flow rate sensor, and a pouring layer data acquisition unit; the temperature and humidity sensor array is fixedly installed on a support near the outlet of the paver or the inlet of the pouring bin surface, with its probe directly contacting or close to the falling concrete flow; the flow rate sensor is installed at a key position of the pouring conduit outlet or the chute; the pouring layer data acquisition unit integrates the signal conditioning circuit of the temperature and humidity sensor array and the flow rate sensor, and is used for preliminary processing and analog-digital conversion of data, and transmits the data to the central controller through wired or wireless mode; the above settings can realize real-time and accurate acquisition of the temperature, humidity and flow rate data of the pouring layer concrete; these data provide a basis for the central controller to adjust the pouring parameters, and ensure the stable quality of the concrete pouring and effectively avoid quality problems caused by abnormal temperature and humidity or improper flow rate.

[0120] In the preferred scheme, the flow rate sensor is a non-contact sensor or a contact sensor, the non-contact sensor is a radar flowmeter or a laser flowmeter, and the contact sensor is a paddle wheel flowmeter; the above settings can meet the requirements of different measurement scenes; the non-contact sensor is suitable for harsh and difficult-to-contact environments, and can reduce the interference to the fluid; the contact sensor has simple structure and low cost, and has high precision in small flow measurement, thereby ensuring the comprehensiveness and accuracy of measurement.

[0121] In the preferred scheme, the cooling layer monitoring module comprises a flowmeter, a temperature sensor group, a pressure sensor, and a cooling layer data acquisition unit; the flowmeter is installed on the main pipeline or key branch pipeline of the cooling water, and the flowmeter is an electromagnetic flowmeter or an ultrasonic flowmeter; the temperature sensor group comprises at least high-precision temperature sensors installed on the inlet pipe and outlet pipe of the cooling water; the pressure sensor is installed on the main pipeline or key node of the cooling water system; the cooling layer data acquisition unit integrates the signals of the flowmeter, the temperature sensor group, and the pressure sensor, is used for signal processing and transmission, and can calculate the cooling effect of a single / area water pipe and transmit the data to the central controller; the above settings can realize comprehensive and accurate monitoring of the running state of the cooling layer; the flowmeter accurately grasps the cooling water flow, the temperature sensor group accurately senses the temperature difference between the inlet and outlet water, the pressure sensor ensures the stable system pressure, and the data acquisition unit efficiently integrates the data, thereby providing strong support for stable operation of the system.

[0122] In a preferred solution, an electric regulating valve controlled by the central controller is installed on the flow meter back pipe in the cooling layer monitoring module; the central controller calculates the optimal flow required by each cooling circuit through an algorithm according to the preset temperature control curve, real-time structural layer temperature, temperature change rate and cooling efficiency, and outputs a control signal to drive the electric regulating valve to act; the above settings can effectively realize precise regulation and control of the cooling flow, ensure that the structural layer temperature changes according to the preset temperature control curve, avoid excessive temperature fluctuations affecting equipment performance, improve the stability and reliability of the entire system, and ensure that the equipment operates efficiently in a suitable temperature environment.

[0123] In a preferred solution, the structural layer monitoring module includes a distributed temperature sensor group, a strain sensor group and a structural layer data acquisition unit; the distributed temperature sensor group is composed of multiple digital temperature sensors or fiber grating temperature sensors resistant to high temperature and high pressure, and is buried in the concrete structure at different depths and positions according to a predetermined spatial grid; the strain sensor group is composed of multiple vibrating wire strain gauges, fiber grating strain sensors or embedded concrete strain gauges, and is arranged in key sections and positions of the concrete structure in cooperation with the temperature sensors; the structural layer data acquisition unit is a distributed data acquisition box or a fiber optic demodulator, which is arranged on or near the structure surface, and is used for power supply for the sensors, acquisition of original signals, calculation of physical quantities, and transmission of data to the central controller through wired or wireless methods; the above settings can realize all-around real-time monitoring of the temperature field and stress field inside the concrete structure, accurately capture the stress state and thermal parameter changes of the structure, provide high-precision, multi-dimensional original data support for structural health assessment, and effectively improve the structural safety warning capability.

[0124] In a preferred solution, the data acquisition units of the distributed temperature sensor group and the strain sensor group of the structural layer monitoring module have edge computing capability, can preliminarily filter, detect and compress data locally, and then upload the processed data to the central controller; the above settings can greatly reduce invalid data transmission and reduce network bandwidth pressure; at the same time, rapid abnormality detection can timely feedback structural abnormalities, provide early warning for subsequent maintenance, ensure safe and stable operation of the structure, and improve the overall monitoring efficiency and reliability.

[0125] In a preferred solution, in the step 1, when the pouring layer monitoring module detects that the temperature and humidity of the concrete exceed the preset threshold or the flow rate deviates from the set range, the central controller issues a warning to prompt the operator to adjust the concrete mix ratio, pouring speed, or automatically outputs a signal to the pouring equipment control system to adjust the discharging speed; the above settings can effectively ensure the stability of the concrete pouring quality and avoid structural defects caused by abnormal parameters; at the same time, the system can record the monitoring data and adjustment records in real time, provide a reliable basis for subsequent quality traceability and process optimization, and further improve the accuracy and reliability of construction.

[0126] In the preferred scheme, in the step 2, the central controller calculates the temperature drop rate and heat dissipation index according to the water passing parameters transmitted by the cooling layer monitoring module, and compares with the preset cooling curve, if the parameters are abnormal, the electric regulating valve of the cooling water system is automatically adjusted to control the flow, or an alarm is sent to the operator to adjust the water temperature; the above settings can effectively ensure that the cooling layer operates according to the predetermined cooling curve, avoid affecting the equipment performance or product quality due to abnormal cooling; at the same time, the combination of automatic adjustment and alarm prompt can improve the cooling efficiency, and enhance the reliability and safety of the system.

[0127] In the preferred scheme, in the step 4, the central controller performs fusion analysis on the multi-source data, establishes the correlation between the parameters of the pouring layer, the cooling layer and the structure layer, draws the temperature field cloud map, the strain distribution map and the development curve inside the structure, compares with the theoretical model and the safety threshold, evaluates the development of concrete hydration heat, temperature gradient, stress concentration and shrinkage and creep, and provides basis for maintenance decision, temperature control measure adjustment and structure safety evaluation; the above settings can effectively improve the intelligent level of concrete construction, and accurately control the key indicators at each stage; according to the analysis result, the maintenance strategy and the temperature control means can be adjusted in time, so that the structure safety and stability are ensured, and the quality hidden danger such as cracking caused by temperature stress and the like is avoided.

[0128] In summary, the present application provides a three-level monitoring device and method for concrete quality, which shows excellent innovation and practicability in the field of mass concrete construction quality control technology. Especially for high-cold high-altitude region hydropower station, bridge pier and other mass concrete structures, the existing technology cannot fully cover the whole life cycle quality monitoring demand from concrete pouring to water cooling, and the present application effectively solves this problem and fills the technical gap in this field.

[0129] The application has many pioneering designs: for the first time, a "pouring layer-cooling layer-structural layer" three-level monitoring system is proposed, which divides the concrete construction quality monitoring into three independent and interrelated levels, realizes the comprehensive, accurate and continuous monitoring of the core parameters of the concrete from the warehouse to the stable state, and this hierarchical monitoring mode is still the first in the industry. In the pouring layer monitoring, the temperature, humidity and flow rate of the concrete are monitored simultaneously, and the central controller is used for comprehensive analysis, which effectively reduces the risk of concrete segregation. This multi-parameter collaborative monitoring method is extremely rare in the field of concrete construction monitoring. The cooling layer monitoring introduces dynamic regulation technology, automatically adjusts the cooling water flow according to the real-time monitoring data, optimizes the cooling efficiency, and its unique real-time feedback regulation mechanism is advanced in the field of concrete cooling monitoring. The structural layer monitoring sets up a long-term monitoring mechanism to continuously evaluate the long-term performance and safety of the concrete structure, and provides improvement suggestions for subsequent concrete construction. This long-term and continuous monitoring method has a significant technical advantage in the field of concrete structure maintenance.

[0130] From the actual effect, the three-level monitoring system successfully solves the data island phenomenon existing in the existing monitoring method, realizes the integration and sharing of data, improves the integrity and consistency of the monitoring data, and provides a reliable basis for comprehensive evaluation of the concrete construction quality. The dynamic regulation technology used in the cooling layer can adjust the cooling strength in real time according to the internal temperature change of the concrete, avoiding the situation of excessive cooling or insufficient cooling, improving the uniformity and stability of the cooling effect, and effectively preventing the generation of temperature cracks. The introduction of the central intelligent control system combines data aggregation, fusion analysis, intelligent early warning and closed-loop regulation, integrates the dispersed monitoring points into an organic whole, significantly improves the controllability and traceability of the concrete construction quality, and realizes intelligent management. In addition, this scheme not only focuses on the quality control in the concrete construction process, but also highly values the long-term performance and safety evaluation of the concrete structure. Through the accumulation and analysis of long-term monitoring data, it provides strong support for the continuous optimization and improvement of construction technology. This whole-cycle and all-around monitoring concept has a significant technical progress in the field of concrete construction.

Claims

1. A three-level concrete quality monitoring device, characterized in that: It includes a pouring layer monitoring module, a cooling layer monitoring module, a structural layer monitoring module, and a central controller. The pouring layer monitoring module is set up at the concrete pouring site, the cooling layer monitoring module is deployed in the cooling water pipe network system inside or on the surface of the concrete structure, and the structural layer monitoring module is embedded inside the concrete structure. The central controller communicates with the pouring layer monitoring module, the cooling layer monitoring module, and the structural layer monitoring module respectively, receives, stores, and processes real-time data from the three monitoring modules, analyzes the concrete state based on preset thresholds and algorithm models, issues early warning information, and outputs control instructions to relevant actuators.

2. The three-level concrete quality monitoring device according to claim 1, characterized in that: The pouring layer monitoring module includes a temperature and humidity sensor array, a flow velocity sensor, and a pouring layer data acquisition unit. The temperature and humidity sensor array is fixedly installed on a bracket near the outlet of the pouring machine or the inlet of the pouring slab, with its probe directly in contact with or close to the falling concrete flow. The flow velocity sensor is installed at the outlet of the pouring pipe or at a key location in the chute. The pouring layer data acquisition unit integrates the signal conditioning circuits of the temperature and humidity sensor array and the flow velocity sensor for preliminary data processing and analog-to-digital conversion, and transmits the data to the central controller via wired or wireless means.

3. The three-level concrete quality monitoring device according to claim 2, characterized in that: The flow velocity sensor can be a non-contact sensor or a contact sensor. The non-contact sensor can be a radar flow meter or a laser flow meter, and the contact sensor can be a paddlewheel flow meter.

4. The three-level concrete quality monitoring device according to claim 3, characterized in that: The cooling layer monitoring module includes a flow meter, a temperature sensor group, a pressure sensor, and a cooling layer data acquisition unit. The flow meter is installed on the main cooling water pipe or a key branch pipe, and the flow meter is an electromagnetic flow meter or an ultrasonic flow meter. The temperature sensor group includes at least high-precision temperature sensors installed on the cooling water inlet pipe and outlet pipe. The pressure sensor is installed on the main cooling water pipe or a key node. The cooling layer data acquisition unit integrates the signals from the flow meter, temperature sensor group, and pressure sensor for signal processing and transmission, and can calculate the cooling effect of a single pipe / area and then transmit the data to the central controller.

5. The three-level concrete quality monitoring device according to claim 4, characterized in that: The cooling layer monitoring module has an electric regulating valve installed on the pipeline behind the flow meter, which is controlled by the central controller. The central controller calculates the optimal flow rate required for each cooling loop based on the preset temperature control curve, real-time structural layer temperature, temperature change rate, and cooling efficiency, and outputs a control signal to drive the electric regulating valve to operate.

6. The three-level concrete quality monitoring device according to claim 5, characterized in that: The structural layer monitoring module includes a distributed temperature sensor group, a strain sensor group, and a structural layer data acquisition unit. The distributed temperature sensor group consists of multiple high-temperature and high-pressure resistant digital temperature sensors or fiber optic temperature sensors, which are embedded in the concrete structure at different depths and locations according to a predetermined spatial grid. The strain sensor group consists of multiple vibrating wire strain gauges, fiber optic strain sensors, or embedded concrete strain gauges, which are arranged in conjunction with the temperature sensors at key sections and locations of the concrete structure. The structural layer data acquisition unit is a distributed data acquisition box or fiber optic demodulator, which is arranged on or near the structural surface to power the sensors, acquire raw signals, calculate physical quantities, and transmit data to the central controller via wired or wireless means.

7. The three-level concrete quality monitoring device according to claim 6, characterized in that: The data acquisition units of the distributed temperature sensor group and strain sensor group of the structural layer monitoring module have edge computing capabilities, enabling them to perform preliminary data filtering, anomaly detection and compression locally, and then upload the processed data to the central controller.

8. A three-level concrete quality monitoring method, applied to the three-level concrete quality monitoring device as described in claim 7, characterized in that, Includes the following steps: Step 1: Activate the pouring layer monitoring module to monitor the temperature, humidity and flow rate of the concrete in real time during the pouring process, and transmit the monitoring data to the central controller; Step 2: After the concrete pouring is completed, start the cooling layer monitoring module to monitor the flow rate, inlet temperature, outlet temperature and water pressure of the cooling water in real time, and transmit the monitoring data to the central controller. Step 3: After the concrete is poured and vibrated but before it sets, the structural layer monitoring module is pre-embedded inside the concrete structure. After the concrete enters the hardening stage, the structural layer monitoring module is activated to monitor the temperature field distribution and internal strain of the concrete in real time and transmit the monitoring data to the central controller. Step 4: The central controller receives, stores, and processes real-time data from the three monitoring modules, analyzes the concrete condition based on preset thresholds and algorithm models, and issues early warning information if the monitoring data is abnormal, and outputs control instructions to the relevant actuators to adjust the construction parameters. The early warning information includes audible and visual alarms and messages, and the relevant actuators include the pouring equipment and cooling water regulating valves.

9. The three-level monitoring method for concrete quality according to claim 8, characterized in that: In step 1, when the concrete pouring layer monitoring module detects that the temperature or humidity of the concrete exceeds the preset threshold or the flow rate deviates from the set range, the central controller issues an early warning, prompting the operator to adjust the concrete mix ratio and pouring speed, or automatically outputs a signal to the pouring equipment control system to adjust the material feeding speed.

10. The three-level monitoring method for concrete quality according to claim 8, characterized in that: In step 2, the central controller calculates the temperature drop rate and heat loss index based on the water flow parameters transmitted by the cooling layer monitoring module, and compares them with the preset cooling curve. If the parameters are abnormal, the electric regulating valve of the cooling water system is automatically adjusted to control the flow rate, or an alarm is issued to prompt the operator to adjust the water source temperature. In step 4, the central controller performs fusion analysis on multi-source data, establishes the correlation between parameters of the pouring layer, cooling layer, and structural layer, and draws temperature field cloud map, strain distribution map and development curve inside the structure. By comparing with theoretical models and safety thresholds, the development of concrete hydration heat, temperature gradient, stress concentration and shrinkage creep are evaluated, providing a basis for maintenance decisions, temperature control measures adjustment and structural safety assessment.

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