Mass concrete temperature monitoring method

Abstract

The invention discloses a mass concrete temperature monitoring method. The method comprises the following specific steps: step 1, planning a monitoring point position; step 2, selecting and installing equipment; step 3, installing and pre-burying a measuring point, step 4, installing and pre-burying an optical fiber, step 5, laying temperature measurement layers, step 6, collecting and monitoring data, and step 7, ending data analysis. According to the invention, through a mode of combining a wireless temperature measurement process and manual measurement, the frequency of manual point measurement can be reduced, manpower consumption is reduced, the comprehensiveness of monitoring data is improved, the monitoring blind area of a traditional point type sensor is avoided, and the possible equipment fault problem of a temperature measurement system is avoided; and data comparison of manual monitoring and wireless monitoring is adopted, so that the reliability of temperature measurement data can be determined, and accident hidden dangers are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete, and in particular relates to a temperature monitoring method for large-volume concrete. Background Art

[0002] In the construction process of large-volume concrete, temperature control is a crucial link. After large-volume concrete is poured and formed, the internal temperature will rise sharply due to the accumulation of hydration heat, forming a significant temperature difference with the surface. Usually, tensile stress will be generated when it exceeds 25°C. When the tensile stress exceeds the tensile strength of the concrete, it will cause through-cracks, threatening the safety and durability of the structure. Therefore, in order to avoid cracks caused by excessive temperature differences in the concrete, temperature detection is required inside the large-volume concrete. When the temperature rise rate inside the concrete is too fast, it will accelerate material aging, while slow cooling can reduce shrinkage stress and avoid structural deformation or cracking. Therefore, through real-time temperature data, the cooling water pipe flow, insulation layer thickness or curing cycle can be dynamically adjusted to ensure that the concrete hardening process meets temperature control standards.

[0003] The main monitoring methods for large-volume concrete currently use manual temperature measurement and wireless temperature measurement. Manual temperature measurement mainly uses the thermocouple method to measure the temperature using the metal thermoelectric potential difference. It requires manual binding of the steel bars, connecting the data line and recording the readings. The data is collected by pre-embedded temperature measuring lines in the concrete. The wireless temperature measurement method uses a wireless sensor network to synchronously connect multiple data lines, thereby collecting multiple temperature data in real time to monitor the internal temperature of the concrete without the need for frequent on-site operations.

[0004] When monitoring large volumes of concrete using the above monitoring methods, both manual and wireless temperature measurement require pre-embedded multiple sets of temperature measuring wires inside the concrete. The main front-end monitoring path still relies on thermocouple monitoring, leading to the following problems during the monitoring process:

[0005] 1. Existing point sensors need to be tied to the steel bars and embedded together with the steel bars. Since the detection end position of the sensor has no fixed structure, the end may be offset and the installation depth may deviate during the embedding process, resulting in data reading errors.

[0006] Although using only point sensors has high spatial resolution and can accurately measure changes at specific locations, there are blind spots in monitoring. If wireless temperature measurement is used and blind trust is placed in the temperature measurement system, manual review may be ignored. If equipment failure is not discovered in time, serious quality accidents may occur. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for monitoring the temperature of large-volume concrete to solve the technical problems raised in the above-mentioned background technology.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for monitoring temperature of large volume concrete, comprising the following specific steps:

[0010] Step 1. Monitoring point planning: Based on the thickness and shape of the structure, calculate the lateral position at the edges, corners, middle and variable cross-section areas of the concrete, and control the spacing between planes, vertical layer spacing and spacing at variable cross-sections.

[0011] Step 2. Equipment selection and installation: Select the TD-3A temperature measuring wire, distributed fiber optic sensor, and circulating water pipe system that need to be embedded. Select the embedded steel bar material that matches the depth of the concrete to be poured. The end height of the embedded steel bar material must be higher than the depth of the concrete to be measured.

[0012] Step 3. Pre-embedded measuring point installation: Weld multiple vertical segments to one side of the embedded steel bar, attach the temperature measuring wire of the point sensor to the side of the steel bar, and use insulating tape to fix the temperature measuring wire along the embedded steel bar. Fix the detection probe position of the temperature measuring wire to the vertical segment with insulating tape, while avoiding covering the metal part of the probe;

[0013] Step 4. Pre-embedded Fiber Installation: In the pre-embedded concrete reinforcement structure, use a cutting device to cut a groove on the surface of the reinforcement inside the concrete. Insert the tightly sheathed fiber into the groove. Then select another group of fibers and lay them radially from the center of the concrete to the edge.

[0014] Step 5. Temperature Measurement Layered Arrangement: Insert the pre-buried steel bars with the temperature probes installed vertically from the top of the concrete structure and tie them to the concrete reinforcement structure to maintain a vertical position. Install the cooling water pipe system, arrange it in a "U" shape, and test the water. Use a circulating water tank and temperature control box to adjust the water temperature. When pouring large volumes of concrete in layers, pre-buried optical fibers are placed in each layer and sleeves are used to protect the joints to ensure continuous monitoring of strain and temperature changes in each layer. Then complete the pouring operation.

[0015] Step 6. Data acquisition and monitoring: Connect the fiber optic sensor to the TD-12 temperature measurement host and data acquisition system, debug the temperature measurement equipment, and collect the initial temperature data before the concrete is poured into the mold. Start continuous monitoring 10 hours after pouring is completed. Measure the temperature every 2 hours for the first 1-5 days, and gradually extend the interval to twice a day in the later period.

[0016] Step 7. Data analysis conclusion: Control the temperature difference between the inside and outside of the concrete to ≤25°C, the cooling rate to ≤2.0°C / d, and the temperature difference between the surface and the internal measuring point to ≤25°C. When the temperature difference exceeds the standard, the warning will be automatically triggered and the circulating water cooling system will be started or the insulation layer will be adjusted to reduce the temperature difference between the inside and outside. When the temperature difference between the inside and outside is stable within 25°C and the cooling rate meets the requirements, the monitoring will be terminated.

[0017] Furthermore, in step 1, the measurement points are arranged at the edges, corners, middle and variable cross-section areas of the concrete. The plane spacing of the measurement points for the embedded steel bars is controlled at 10-15m, and the points are layered according to the thickness in the vertical direction. Usually, a temperature measurement point is set every 0.5m, focusing on the temperature changes in the middle, 5cm from the surface and 5cm from the bottom. The variable cross-section is encrypted through optical fiber distribution.

[0018] Furthermore, in step 3, the vertical section also uses the same steel bar segment as the embedded steel bar, and this steel bar segment is welded vertically to one side of the embedded steel bar. The number of steel bar segments and the number and position of layered measuring points in the vertical direction are synchronized, and the temperature measuring line probe must be at the bottom of the vertical section when binding.

[0019] Furthermore, in step 3, a plum blossom-shaped layout is adopted, and a temperature measuring area is set up for every 100 m2. The temperature measuring lines are embedded and numbered and fixed to avoid direct contact with the steel bars. The embedded temperature measuring lines must be completed before pouring. At the same time, the probe position of the temperature measuring line strictly corresponds to the measuring point. The exposed plug at the top of the temperature measuring line needs to be covered with a plastic bag and wrapped with tape for moisture-proof protection.

[0020] Furthermore, in step 4, the optical fibers laid out radially from the concrete centroid to the edge need to be fixed by hanging S-shaped rings to form a monitoring network covering the entire cross section.

[0021] Furthermore, in step 6, during the process, manual temperature measurement is performed once every three days through the pre-buried point sensor, and the manual temperature measurement data is collected and compared with the wireless temperature measurement data.

[0022] Furthermore, in step 7, it is necessary to combine the BIM model to perform temperature control simulation, compare the actual monitoring data, optimize the maintenance strategy, and after the monitoring is terminated, export the temperature change curve, alarm records and other data to form a monitoring report for archiving and quality traceability.

[0023] The beneficial effects of the present invention compared to the prior art are:

[0024] 1. The present invention combines wireless temperature measurement with manual measurement, which not only reduces the frequency of manual measurement points and reduces manpower consumption, but also improves the comprehensiveness of monitoring data, avoids the monitoring blind spots of traditional point sensors, and avoids the equipment failure problems that may exist in the temperature measurement system. By comparing the data of manual monitoring and wireless monitoring, the reliability of temperature measurement data can be determined, reducing potential accidents.

[0025] 2. The present invention welds a vertical section made of the same steel bar material on one side of the embedded steel bar. When fixing the temperature measuring line, the probe part can be fixed to the bottom position of the vertical section with tape, thereby providing protection for the detection probe during the pouring process and reinforcing the probe position, thereby minimizing the impact on the probe during the pouring process, avoiding depth and point deviations of the temperature measuring line probe, maintaining the uniformity of the depth layered measuring point position, and facilitating subsequent monitoring.

[0026] 3. The present invention combines the suspended S-shaped hanging ring with the steel structure, fixes the optical fiber arranged in the radiation structure, coordinates the arrangement of the two groups of optical fibers, and connects with the temperature measurement host for monitoring. This can effectively reduce the temperature measurement blind spots of the detection probe at the temperature measurement point and reduce the detection loopholes of the variable cross-section, thereby more comprehensively monitoring the temperature inside the concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the concrete temperature monitoring steps of the present invention;

[0028] Figure 2 It is a schematic diagram of the layout structure of the embedded steel bars in the present invention. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and by way of preferred embodiments. However, it should be noted that many of the details listed in this specification are merely provided to help the reader gain a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be practiced even without these specific details.

[0030] The present invention provides a method for monitoring the temperature of large-volume concrete. Figure 1 As shown, the specific steps include:

[0031] Step 1. Monitoring point planning: Based on the thickness and shape of the structure, calculate the lateral position at the edges, corners, middle and variable cross-section areas of the concrete, and control the spacing between planes, vertical layer spacing and spacing at variable cross-sections.

[0032] Step 2. Equipment selection and installation: Select the TD-3A temperature measuring wire, distributed fiber optic sensor, and circulating water pipe system that need to be embedded. Select the embedded steel bar material that matches the depth of the concrete to be poured. The end height of the embedded steel bar material must be higher than the depth of the concrete to be measured.

[0033] Step 3. Pre-embedded measuring point installation: Weld multiple vertical segments to one side of the embedded steel bar, attach the temperature measuring wire of the point sensor to the side of the steel bar, and use insulating tape to fix the temperature measuring wire along the embedded steel bar. Fix the detection probe position of the temperature measuring wire to the vertical segment with insulating tape, while avoiding covering the metal part of the probe;

[0034] Step 4. Pre-embedded Fiber Installation: In the pre-embedded concrete reinforcement structure, use a cutting device to cut a groove on the surface of the reinforcement inside the concrete. Insert the tightly sheathed fiber into the groove. Then select another group of fibers and lay them radially from the center of the concrete to the edge.

[0035] Step 5. Temperature Measurement Layered Arrangement: Insert the pre-buried steel bars with the temperature probes installed vertically from the top of the concrete structure and tie them to the concrete reinforcement structure to maintain a vertical position. Install the cooling water pipe system, arrange it in a "U" shape, and test the water. Use a circulating water tank and temperature control box to adjust the water temperature. When pouring large volumes of concrete in layers, pre-buried optical fibers are placed in each layer and sleeves are used to protect the joints to ensure continuous monitoring of strain and temperature changes in each layer. Then complete the pouring operation.

[0036] Step 6. Data acquisition and monitoring: Connect the fiber optic sensor to the TD-12 temperature measurement host and data acquisition system, debug the temperature measurement equipment, and collect the initial temperature data before the concrete is poured into the mold. Start continuous monitoring 10 hours after pouring is completed. Measure the temperature every 2 hours for the first 1-5 days, and gradually extend the interval to twice a day in the later period.

[0037] Step 7. Data analysis conclusion: Control the temperature difference between the inside and outside of the concrete to ≤25°C, the cooling rate to ≤2.0°C / d, and the temperature difference between the surface and the internal measuring point to ≤25°C. When the temperature difference exceeds the standard, the warning will be automatically triggered and the circulating water cooling system will be started or the insulation layer will be adjusted to reduce the temperature difference between the inside and outside. When the temperature difference between the inside and outside is stable within 25°C and the cooling rate meets the requirements, the monitoring will be terminated.

[0038] In step 3, in step 1, the measuring points are arranged at the edges, corners, middle and variable cross-section areas of the concrete. The plane spacing of the measuring points of the embedded steel bars is controlled at 10-15m, and the points are layered according to the thickness in the vertical direction. Usually, a temperature measuring point is set every 0.5m, focusing on the temperature changes in the middle, 5cm from the surface and 5cm from the bottom. The variable cross-section is encrypted through optical fiber distribution.

[0039] The measuring points arranged at the edges, corners, middle and variable cross-section areas of the concrete mentioned above need to be arranged in accordance with the detection standards based on the size and shape of the poured concrete. By controlling the measuring point plane at 10-15m and coordinating the corresponding thickness layer points, a measuring point matrix can be formed to provide temperature data at multiple points and angles in the concrete for subsequent detection, making it easier to control the temperature difference.

[0040] Furthermore, in step 3, the vertical section also uses the same steel bar segment as the embedded steel bar, and this steel bar segment is welded vertically to one side of the embedded steel bar. The number of steel bar segments and the number and position of layered measuring points in the vertical direction are synchronized, and the temperature measuring line probe must be at the bottom of the vertical section when binding.

[0041] From the above description, it can be seen that by welding a vertical section of the same steel bar material on one side of the embedded steel bar, the probe part can be fixed to the bottom position of the vertical section with tape when fixing the temperature measuring line, providing protection for the detection probe during the pouring process and reinforcing the probe position, thereby minimizing the impact of the pouring process on the probe, avoiding depth and point deviations of the temperature measuring line probe, maintaining the uniformity of the depth layered measuring point position, and facilitating subsequent monitoring.

[0042] Furthermore, in step 3, a plum blossom-shaped layout is adopted, and a temperature measuring area is set up for every 100 m2. The temperature measuring lines are embedded and numbered and fixed to avoid direct contact with the steel bars. The embedded temperature measuring lines need to be completed before pouring. At the same time, the probe position of the temperature measuring line strictly corresponds to the measuring point. The exposed plug at the top of the temperature measuring line needs to be covered with a plastic bag and wrapped with tape for moisture-proof protection.

[0043] From the above description, it can be seen that this layout method forms a measurement point matrix by adopting a plum blossom-shaped layout, and sets a temperature measurement zone for every 100 square meters. It can facilitate overall planning and monitoring according to the zoning situation when conducting manual or wireless monitoring, and facilitate the coordination and management of subsequent measurement point data. Before pouring, the exposed plug at the top of the temperature measuring line is covered with a plastic bag to provide effective moisture-proof effect, thereby preventing the exposed plug from being pressed into the pouring layer during concrete pouring, or from long-term contact with moisture to cause corrosion or rust, which affects subsequent monitoring use.

[0044] Furthermore, in step 4, the optical fibers arranged radially from the concrete centroid to the edge need to be fixed in the radial structure by hanging S-shaped rings to form a monitoring network covering the entire cross section.

[0045] From the above description, it can be seen that when distributing the optical fibers, one group of optical fibers is embedded in the groove of the steel structure, while the other group of optical fibers is radially arranged from the centroid of the concrete to the edge. The optical fibers arranged in the radial structure are fixed by hanging S-shaped rings and combined with the steel structure. Through the arrangement of the two groups of optical fibers, they are connected to the temperature measurement host for monitoring, which can effectively reduce the temperature measurement blind spots of the detection probes at the temperature measurement points and reduce the detection loopholes of variable cross-sections, thereby more comprehensively monitoring the temperature inside the concrete.

[0046] Furthermore, in step 6, during the process, manual temperature measurement is performed once every three days using pre-buried point sensors, and the manual temperature measurement data is collected and compared with the wireless temperature measurement data.

[0047] From the above description, it can be seen that construction workers manually monitor the layered points point by point by connecting a handheld thermometer to the exposed plug at the top of the temperature measuring line of the embedded steel bars at an interval of once every three days during the initial stage of concrete forming. By combining the wireless temperature measurement process with manual measurement, not only can the frequency of manual measurement points be reduced and manpower consumption be reduced, but the comprehensiveness of the monitoring data can also be improved, avoiding the monitoring blind spots of traditional point sensors and possible equipment failure problems in the temperature measurement system. By comparing the data of manual monitoring and wireless monitoring, the reliability of the temperature measurement data can be determined and the potential for accidents can be reduced.

[0048] Several preferred embodiments or application examples are listed below to help those skilled in the art better understand the technical content of the present invention and the technical contribution of the present invention relative to the prior art.

[0049] Example 1:

[0050] A method for monitoring temperature of large volume concrete, the specific steps include the following

[0051] Step 1. Monitoring point planning: Based on the thickness and shape of the structure, calculate the lateral position at the edges, corners, middle and variable cross-section areas of the concrete, and control the spacing between planes, vertical layer spacing and spacing at variable cross-sections.

[0052] Step 2. Equipment selection and installation: Select the TD-3A temperature measuring line and circulating water pipe system that need to be embedded, and select the embedded steel bar material that matches the depth of the concrete to be poured. The end height of the embedded steel bar material needs to be higher than the depth of the concrete to be measured;

[0053] Step 3. Pre-embedded measuring point installation: Weld multiple vertical segments to one side of the embedded steel bar, attach the temperature measuring wire of the point sensor to the side of the steel bar, and use insulating tape to fix the temperature measuring wire along the embedded steel bar. Fix the detection probe position of the temperature measuring wire to the vertical segment with insulating tape, while avoiding covering the metal part of the probe;

[0054] Step 4. Temperature measurement layer layout: Insert the embedded steel bars with the temperature probes installed vertically from the top of the concrete structure and tie them to the concrete reinforcement structure to maintain a vertical position. Install the cooling water pipe system, arrange it in a "U" shape and test the water. Use the circulating water tank and temperature control box to adjust the water temperature, and then complete the pouring operation.

[0055] Step 5. Data collection and monitoring: Temperature measurement begins 10 hours after concrete pouring is completed. In the initial 1-5 days, the temperature is measured every 2 hours, and then gradually extended to twice a day. Workers use a handheld intelligent thermometer, such as the TD-12 host, connect the temperature measuring line plug to the instrument, and read the temperature of each measuring point one by one.

[0056] Step 6. Data analysis conclusion: Control the temperature difference between the inside and outside of the concrete to ≤25℃, the cooling rate to ≤2.0℃ / d, and the temperature difference between the surface and the internal measuring point to ≤25℃. When the temperature difference exceeds the standard, start the circulating water cooling system or adjust the insulation layer to reduce the temperature difference between the inside and outside. When the temperature difference between the inside and outside is stable within 25℃ and the cooling rate meets the requirements, terminate the monitoring.

[0057] This embodiment welds a vertical section made of the same steel bar material on one side of the embedded steel bar. When fixing the temperature measuring line, the probe part can be fixed to the bottom position of the vertical section with tape, thereby providing protection for the detection probe during the pouring process and reinforcing the probe position, reducing the impact of pouring on the probe, and avoiding depth point deviation of the temperature measuring line probe. However, the method of monitoring only through the steel bar and the temperature measuring line still has monitoring blind spots in the concrete layout, the temperature side data is not comprehensive, and manual monitoring is required throughout the process. The operation is frequent and consumes the manpower of construction workers, which is inefficient.

[0058] Comparative Example 1:

[0059] A method for monitoring temperature of large volume concrete, the specific steps include the following

[0060] Step 1. Monitoring point planning: Based on the thickness and shape of the structure, calculate the lateral position at the edges, corners, middle and variable cross-section areas of the concrete, and control the spacing between planes, vertical layer spacing and spacing at variable cross-sections.

[0061] Step 2. Equipment selection and installation: Select the TD-3A temperature measuring line and circulating water pipe system that need to be embedded, and select the embedded steel bar material that matches the depth of the concrete to be poured. The end height of the embedded steel bar material needs to be higher than the depth of the concrete to be measured;

[0062] Step 3. Pre-embedded measuring point installation: Attach the temperature measuring wire of the point sensor to one side of the steel bar, and use insulating tape to fix the temperature measuring wire along the pre-embedded steel bar;

[0063] Step 4. Temperature measurement layer layout: Insert the embedded steel bars with the temperature probes installed vertically from the top of the concrete structure and tie them to the concrete reinforcement structure to maintain a vertical position. Install the cooling water pipe system, arrange it in a "U" shape and test the water. Use the circulating water tank and temperature control box to adjust the water temperature, and then complete the pouring operation.

[0064] Step 5. Data collection and monitoring: Temperature measurement begins 10 hours after concrete pouring is completed. In the initial 1-5 days, the temperature is measured every 2 hours, and then gradually extended to twice a day. Workers use a handheld intelligent thermometer, such as the TD-12 host, connect the temperature measuring line plug to the instrument, and read the temperature of each measuring point one by one.

[0065] Step 6. Data analysis conclusion: Control the temperature difference between the inside and outside of the concrete to ≤25℃, the cooling rate to ≤2.0℃ / d, and the temperature difference between the surface and the internal measuring point to ≤25℃. When the temperature difference exceeds the standard, start the circulating water cooling system or adjust the insulation layer to reduce the temperature difference between the inside and outside. When the temperature difference between the inside and outside is stable within 25℃ and the cooling rate meets the requirements, terminate the monitoring.

[0066] In this comparison, the temperature measuring line is pre-buried using the traditional method. The point sensor needs to be tied to the steel bar and then pre-buried together with the steel bar. Since the detection end position of the sensor has no fixed structure, the end will be offset and the installation depth will deviate during the pre-buried process, resulting in data reading errors. At the same time, manual monitoring is still required for subsequent temperature reading, which is time-consuming and labor-intensive.

[0067] In summary, the present invention provides a method for monitoring the temperature of large-volume concrete. First, it is necessary to calculate the lateral position at the edge, corner, middle and variable cross-section area of ​​the concrete according to the thickness and shape of the structure, control the plane spacing, vertical layer spacing and spacing at the variable cross-section, and the plane spacing of the measuring points of the embedded steel bars is controlled at 10-15m. The vertical direction is layered according to the thickness, and temperature measuring points are usually set every 0.5m. Focus on the temperature changes in the middle, 5cm from the surface and 5cm from the bottom. The variable cross-section is encrypted through optical fiber distribution. The TD-3A type temperature measuring line and distributed optical fiber sensor and circulating water pipe system that need to be embedded are selected, and the embedded steel bar material that matches the depth of the concrete to be poured is selected. The end height of the embedded steel bar material needs to be higher than the depth of the concrete to be measured. Multiple groups of vertical segments are welded on one side of the embedded steel bar. The vertical segment also uses the same steel bar segment as the embedded steel bar. This steel bar segment is welded vertically to one side of the embedded steel bar. The number of steel bar segments is synchronized with the number and position of layered measuring points in the vertical direction, and the temperature measuring line probe needs to be at the bottom of the vertical segment when binding. The temperature measuring line of the point sensor is attached to one side of the steel bar. The temperature measuring line is fixed along the embedded steel bar with insulating tape. The detection probe position of the temperature measuring line is fixed to the vertical segment with insulating tape, while avoiding covering the metal part of the probe. The overall layout adopts a plum blossom shape, and a temperature measuring area is set for every 100 square meters. The temperature measuring lines are embedded and numbered. Fixed to avoid direct contact with the steel bars. The embedded temperature measuring wires must be completed before pouring. At the same time, the probe position of the temperature measuring wire strictly corresponds to the measuring point. The exposed plug at the top of the temperature measuring wire needs to be covered with a plastic bag and wrapped with tape for moisture-proof protection. In the steel bar structure embedded in the concrete, a cutting device is used to cut a groove on the surface of the steel bar inside the concrete. The tight sheathed optical fiber is embedded in the groove, and another group of optical fibers is selected to be radially arranged from the center of the concrete to the edge. The embedded steel bar with the temperature measuring wire probe installed is placed vertically from the top of the concrete structure and tied and fixed with the concrete steel bar structure to keep it vertical. The cooling water pipe system is installed and arranged in a "U" shape and water is tested. Combined with the circulating water tank and temperature control The water temperature is regulated by a box. During the layered pouring of large-volume concrete, optical fibers are embedded in each layer and the joints are protected by casing to ensure continuous monitoring of strain and temperature changes in each layer. After the pouring operation is completed, the optical fiber sensor is connected to the TD-12 temperature measurement host and data acquisition system. The temperature measurement equipment is debugged and the initial temperature data before the concrete is placed in the mold is collected. Continuous monitoring is initiated 10 hours after the pouring is completed. The temperature is measured every 2 hours for the first 1-5 days, and the interval is gradually extended to twice a day in the later period. Every three days during the process, manual temperature measurement is carried out using pre-embedded point sensors. The manual temperature measurement data is collected and compared with the wireless temperature measurement data. The temperature difference between the inside and outside of the concrete is controlled to be ≤25°C, and the cooling rate is ≤2.0°C / day, with the temperature difference between the surface and internal measuring points ≤25°C. During temperature monitoring, BIM models must be integrated for temperature control simulation, compared with actual monitoring data, and maintenance strategies optimized. After monitoring is terminated, temperature change curves, alarm records, and other data are exported to create a monitoring report for archiving and quality traceability. When the temperature difference exceeds the standard, an early warning is automatically triggered, and the circulating water cooling system is activated or the insulation layer is adjusted to reduce the internal and external temperature difference. Monitoring is terminated when the internal and external temperature difference stabilizes within 25°C and the cooling rate meets the requirements.

[0068] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for monitoring temperature of large volume concrete, characterized by: The specific steps include the following: Step 1. Monitoring point planning: Based on the thickness and shape of the structure, calculate the lateral position at the edges, corners, middle and variable cross-section areas of the concrete, and control the spacing between planes, vertical layer spacing and spacing at variable cross-sections. Step 2. Equipment selection and installation: Select the TD-3A temperature measuring wire, distributed fiber optic sensor, and circulating water pipe system that need to be embedded. Select the embedded steel bar material that matches the depth of the concrete to be poured. The end height of the embedded steel bar material must be higher than the depth of the concrete to be measured. Step 3. Pre-embedded measuring point installation: Weld multiple vertical segments to one side of the embedded steel bar, attach the temperature measuring wire of the point sensor to the side of the steel bar, and use insulating tape to fix the temperature measuring wire along the embedded steel bar. Fix the detection probe position of the temperature measuring wire to the vertical segment with insulating tape, while avoiding covering the metal part of the probe; Step 4. Pre-embedded Fiber Installation: In the pre-embedded concrete reinforcement structure, use a cutting device to cut a groove on the surface of the reinforcement inside the concrete. Insert the tightly sheathed fiber into the groove. Then select another group of fibers and lay them radially from the center of the concrete to the edge. Step 5. Temperature Measurement Layered Arrangement: Insert the pre-buried steel bars with the temperature probes installed vertically from the top of the concrete structure and tie them to the concrete reinforcement to maintain a vertical position. Install the cooling water pipe system, arrange it in a "U" shape, and test the water. Use a circulating water tank and temperature control box to adjust the water temperature. When pouring large volumes of concrete in layers, pre-buried optical fibers are placed in each layer and sleeves are used to protect the joints to ensure continuous monitoring of strain and temperature changes in each layer. Then, complete the pouring operation. Step 6. Data acquisition and monitoring: Connect the fiber optic sensor to the TD-12 temperature measurement host and data acquisition system, debug the temperature measurement equipment, and collect the initial temperature data before the concrete is poured into the mold. Start continuous monitoring 10 hours after pouring is completed. Measure the temperature every 2 hours for the first 1-5 days, and gradually extend the interval to twice a day in the later period. Step 7. Data analysis conclusion: Control the temperature difference between the inside and outside of the concrete to ≤25°C, the cooling rate to ≤2.0°C / d, and the temperature difference between the surface and the internal measuring point to ≤25°C. When the temperature difference exceeds the standard, the warning will be automatically triggered and the circulating water cooling system will be started or the insulation layer will be adjusted to reduce the temperature difference between the inside and outside. When the temperature difference between the inside and outside is stable within 25°C and the cooling rate meets the requirements, the monitoring will be terminated.

2. A method for monitoring temperature of mass concrete according to claim 1, characterized in that: In step 1, the measuring points are arranged at the edges, corners, middle and variable cross-section areas of the concrete. The plane spacing of the measuring points of the embedded steel bars is controlled at 10-15m, and the points are layered according to the thickness in the vertical direction. Usually, a temperature measuring point is set every 0.5m, focusing on the temperature changes in the middle, 5cm from the surface and 5cm from the bottom. The variable cross-section is encrypted by optical fiber distribution.

3. The method for monitoring temperature of mass concrete according to claim 1, wherein: In step 3, the vertical section also uses the same steel bar segment as the embedded steel bar, and this steel bar segment is welded vertically to one side of the embedded steel bar. The number of steel bar segments is synchronized with the number and position of layered measuring points in the vertical direction, and the temperature measuring line probe needs to be at the bottom of the vertical section when binding.

4. The method for monitoring temperature of mass concrete according to claim 1, wherein: In step 3, a plum blossom-shaped layout is adopted, and a temperature measuring area is set up for every 100 m2. The temperature measuring lines are embedded and numbered to avoid direct contact with the steel bars. The embedded temperature measuring lines need to be completed before pouring. At the same time, the probe position of the temperature measuring line strictly corresponds to the measuring point. The exposed plug at the top of the temperature measuring line needs to be covered with a plastic bag and wrapped with tape for moisture-proof protection.

5. The method for monitoring temperature of mass concrete according to claim 1, wherein: In step 4, the optical fibers arranged radially from the concrete centroid to the edge need to be fixed in the radial structure by hanging S-shaped rings to form a monitoring network covering the entire cross section.

6. The method for monitoring temperature of mass concrete according to claim 1, wherein: In step 6, the temperature is manually measured every three days using the pre-buried point sensor, and the manual temperature measurement data is collected and compared with the wireless temperature measurement data.

7. The method for monitoring temperature of mass concrete according to claim 1, wherein: In step 7, it is necessary to combine the BIM model to perform temperature control simulation, compare the actual monitoring data, optimize the maintenance strategy, and after the monitoring is terminated, export the temperature change curve, alarm records and other data to form a monitoring report for archiving and quality traceability.

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