High ductility ecc-based reinforcement structure for existing building structure and construction method thereof

Abstract

This invention discloses a crack-resistant reinforcement structure and construction method for existing building structures based on high-ductility ECC (Extensive Cemented Concrete). The method includes: employing a multi-layer composite structural system, utilizing high-ductility ECC material combined with fiber mesh and steel fiber composite reinforcement, radial energy-dissipating ribs, and shear keyways, etc., combined with interfacial bonding, crack resistance, and stress release capabilities, effectively inhibiting crack development in existing concrete components and improving the overall stiffness, ductility, and shear performance of the structure; and through an improved adaptive threshold comparison algorithm, introducing dynamic weighting factors and adaptive safety limits, dynamically correcting judgment deviations caused by environmental temperature and humidity and material aging, enabling long-term stable monitoring of structural status, accurate identification of safety hazards, and reduction of false alarms and missed alarms, achieving intelligent safety management throughout the entire lifecycle of the reinforced structure. This invention solves the problems of poor collaborative deformation capacity, high recurrence rate of defects after long-term use, and long and error-prone manual inspection cycles in existing reinforcement systems.

Description

Technical Field

[0001] This invention relates to the field of building structure reinforcement and renovation technology, specifically to a crack-resistant reinforcement structure for existing building structures based on high ductility ECC and its construction method. Background Technology

[0002] Currently, mainstream reinforcement methods in the industry include bonding carbon fiber cloth, cladding with steel plates, pouring ordinary concrete, and applying repair mortar. These methods generally suffer from problems such as insufficient ductility, easy cracking at the interface between new and old layers, peeling of the reinforcement layer, and stress concentration at joints. High-ductility ECC is gradually being used due to its advantages such as high tensile strength, energy dissipation through multiple cracks, and self-healing cracks. However, current applications are mostly simple surface coatings without layered structural optimization based on the stress characteristics of the component. This results in poor coordinated deformation capacity of the reinforcement system and a high recurrence rate of defects after long-term use.

[0003] Meanwhile, traditional reinforcement projects can only address post-incident damage and lack a means of routinely monitoring the stress, deformation, and crack development of the reinforcement system and the original structure. After reinforcement, relying solely on regular manual inspections results in long inspection cycles and significant human error, making it difficult to detect hidden problems such as minute cracks, micro-voids at interfaces, and abnormal stress in a timely manner. In particular, weak locations such as beam-column joints and sections with original cracks are prone to sudden safety hazards if stress exceeds limits or deformation continues to increase.

[0004] Therefore, to solve the above problems, a crack-resistant reinforcement structure for existing building structures based on high ductility ECC and its construction method are proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a crack-resistant reinforcement structure and construction method for existing building structures based on high-ductility ECC. By adopting a multi-layer composite structural system, utilizing high-ductility ECC material combined with fiber mesh and steel fiber composite reinforcement, radial energy-dissipating ribs, and shear keyways, and combining interfacial bonding, crack resistance, and stress release capabilities, it can effectively inhibit the development of cracks in existing concrete components and improve the overall stiffness, ductility, and shear performance of the structure. Furthermore, through an improved adaptive threshold comparison algorithm, dynamic weighting factors and adaptive safety limits are introduced to dynamically correct judgment deviations caused by environmental temperature and humidity and material aging. This not only enables long-term stable monitoring of the structural status but also accurately identifies safety hazards, reduces the probability of false alarms and missed alarms, and achieves intelligent safety management of the reinforced structure throughout its entire life cycle, thus solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A crack-resistant reinforcement structure for existing building structures based on high-ductility ECC is installed on the outer surface of existing concrete structural members, comprising: a base treatment layer, an interface reinforcement layer, a main crack-resistant reinforcement layer, and a surface protection layer arranged sequentially from the inside to the outside; the main crack-resistant reinforcement layer includes conventional sections and reinforced sections corresponding to cracks in the original member, with a fiber mesh + steel fiber composite reinforcement embedded inside the reinforced sections; at member corners and stress concentration locations at beam-column joints, ECC chamfered corner reinforcement structures with radial energy-dissipating ribs are provided, integrated with the main crack-resistant reinforcement layer, and shear keyways are provided at the interface between the ECC chamfered corner reinforcement structure and the original member; the reinforcement structure also integrates an intelligent monitoring system, which includes:

[0008] The pre-embedded sensing unit consists of a distributed fiber optic strain sensor, a flexible crack sensing strip, a temperature and humidity sensing probe, and a nodal strain sensing module. It is configured to collect data through a preset sampling frequency. The distributed fiber optic strain sensor collects the overall strain distribution data of the main crack-resistant reinforcement layer and the component body in real time. The temperature and humidity sensing probe monitors the crack width change and the development of the crack displacement. The nodal strain sensing module monitors the stress change and strain concentration in the nodal area.

[0009] The external data early warning unit is configured to receive and aggregate real-time data collected by the pre-embedded sensor unit through a local acquisition terminal. Based on the built-in edge computing module, an improved adaptive threshold comparison algorithm is used to compare the real-time data with the preset safety limit.

[0010] When the collected data exceeds the preset safety limit, the audible and visual warning device is triggered to issue an audible and visual alarm, and alarm information is simultaneously pushed to the remote platform based on wired transmission technology.

[0011] Furthermore, the external data early warning unit, based on the built-in edge computing module, employs an improved adaptive threshold comparison algorithm to compare real-time data with preset safety limits, specifically as follows:

[0012] A data interaction channel with the pre-embedded sensing unit is established based on wired communication technology. In each sampling period, the measured data output by the sensing unit, real-time ambient temperature, real-time ambient humidity, and the cumulative service time of the component after self-reinforcement in the historical records are read synchronously.

[0013] Load the preset baseline safety limits, temperature and humidity reference values, service duration baseline values, various correction coefficients, and deviation judgment thresholds;

[0014] Based on the collected real-time data and initialization parameters, a dynamic weighting factor and an adaptive safety limit mechanism are introduced to calculate the standardized relative deviation value.

[0015] The standardized relative deviation value obtained by calculation is compared with the preset deviation judgment threshold. If the standardized relative deviation value is less than the deviation judgment threshold, the component is judged to be in normal operating condition, and the process is repeated for the next sampling period.

[0016] If the standardized relative deviation value is greater than the deviation judgment threshold range, the monitoring data is judged to be out of limit, an alarm command is immediately issued to the audible and visual early warning device, and the alarm information and all current calculation data are pushed to the remote management platform through wired transmission technology.

[0017] Furthermore, by introducing a dynamic weighting factor and an adaptive safety limit mechanism, the standardized relative deviation value is calculated using the following formula:

[0018]

[0019] In the formula, Represented as Standardized relative deviation at time; Represented as Measured data collected by the time-sensing unit; Represented as the component's baseline safety limit; This represents the initial baseline value of the dynamic deviation weighting factor; This is expressed as the temperature and humidity coupling attenuation coefficient; This is expressed as the temperature and humidity coupling difference. This is expressed as a temperature influence coefficient; This is expressed as the humidity influence coefficient; Expressed as a relative change in temperature; Expressed as a relative change in humidity; This is expressed as the component aging correction factor; This represents the cumulative service life of the component since the reinforcement was completed. This is represented as a reference value for service duration.

[0020] Furthermore, the pre-embedded sensing unit acquires data through a preset sampling frequency, specifically as follows:

[0021] The distributed fiber optic strain sensor collects strain distribution data at a preset first sampling frequency, while the flexible crack sensing strip, temperature and humidity sensing probe and nodal strain sensing module operate synchronously in a low-power standby mode.

[0022] When the rate of change of strain data calculated in real time by the local acquisition terminal exceeds the preset rate of change threshold, it is marked as an abnormal event and an abnormal signal is immediately output.

[0023] The distributed fiber optic strain sensor, flexible crack sensing strip, temperature and humidity sensing probe and nodal strain sensing module are simultaneously triggered to switch to the preset second sampling frequency and acquire data synchronously with the distributed fiber optic strain sensor.

[0024] The second sampling frequency is higher than the first sampling frequency;

[0025] When the strain data change rate calculated in real time by the local acquisition terminal is within the preset change rate threshold and continues to maintain a preset stable duration, the control unit switches each sensing element in the embedded sensing unit back to the initial normal acquisition mode.

[0026] Furthermore, when the rate of change of strain data calculated in real time by the local acquisition terminal is greater than the preset rate of change threshold, the start time period of the abnormal event is defined by the preset time window before and after the trigger time.

[0027] Automatically capture all raw data output by all sensing elements within the time window, and mark the data sequence within this time period as key data of abnormal events;

[0028] The marked key data sequences are divided into independent storage partitions for archiving and preservation; and the acquisition time, sampling frequency and trigger type of the data are recorded synchronously to completely preserve the time-series change log of the component's stress, cracks and environmental parameters.

[0029] Furthermore, the base treatment layer is a rough base surface formed after the component surface is roughened and loose concrete is removed. The base treatment layer has a crack sealing section corresponding to the original component crack position. The crack sealing section is a flexible sealant filled in the crack groove.

[0030] Furthermore, the interface enhancement layer is a modulus gradient double-layer structure, consisting of an inner low-modulus flexible buffer layer and an outer high-modulus rigid anchoring layer, with the surface of the high-modulus rigid anchoring layer having a micro-dimple / serrated interlocking structure.

[0031] Furthermore, the main crack-resistant reinforcement layer is made of high-ductility ECC material, with pre-set micro-energy-dissipating joints according to the stress direction of the component, and the joints are filled with flexible sealing material.

[0032] Furthermore, the distributed optical fiber strain sensor is arranged along the entire length of the main crack-resistant reinforcement layer, the flexible crack sensing strip is arranged in the crack area of ​​the original component and around the micro-energy-consuming joint, the temperature and humidity sensing probe is dispersed inside the main crack-resistant reinforcement layer, the nodal strain sensing module is arranged in the core stress part of the beam-column joint reinforcement area, and a flame-retardant protective sleeve is sleeved on the outside of the sensing line.

[0033] A method for implementing crack-resistant reinforcement of existing building structures based on high-ductility ECC includes the following steps:

[0034] S1: Roughen the outer surface of the existing concrete structural members to form a base treatment layer; and groove the original cracks in the members and fill the grooves with flexible sealant to form crack sealing sections.

[0035] S2: A low-modulus flexible buffer layer and a high-modulus rigid anchoring layer are sequentially applied on the outside of the base treatment layer to form an interface reinforcement layer with a modulus gradient double-layer structure.

[0036] S3: Distributed fiber optic strain sensors are deployed along the entire length of the main crack-resistant reinforcement layer according to the preset points. Flexible crack sensing strips are deployed in the crack area of ​​the component and around the micro-energy-consuming joint. Temperature and humidity sensing probes are distributed inside the main crack-resistant reinforcement layer. Nodal strain sensing modules are deployed at the core stress-bearing parts of the beam-column joint.

[0037] S4: The main crack-resistant reinforcement layer is cast in sections using high-ductility ECC material, forming conventional sections and corresponding reinforced sections for component cracks. Fiber mesh with beveled edges and steel fiber composite reinforcement are embedded in the reinforced sections. Micro-energy-dissipating joints are set in the main crack-resistant reinforcement layer along the component's stress direction, and flexible sealing material is filled in the joints.

[0038] S5: At the corners of the components and the stress concentration points of the beam-column joints, an ECC chamfered corner reinforcement structure with radial energy-dissipating ribs is integrally cast with the main crack-resistant reinforcement layer, and a shear keyway is opened at the interface between the ECC chamfered corner reinforcement structure and the original component.

[0039] S6: A protective layer is applied to the outer surface of the main crack-resistant reinforcement layer and the ECC chamfered corner reinforcement structure.

[0040] S7: The reinforced structure after construction shall be cured in accordance with the curing requirements of high ductility ECC materials until the overall strength reaches the design standard;

[0041] S8: Install an external data early warning unit in a concealed location on the original component, electrically connect the external data early warning unit to the pre-embedded sensing unit, and perform insulation and waterproof protection treatment on the connection line;

[0042] S9: Power on the intelligent monitoring system for self-test, input the benchmark safety limit, temperature and humidity reference values, various correction coefficients, sampling frequency, judgment threshold and other operating parameters, and after completing the debugging of the acquisition logic and threshold comparison algorithm, put it into normal use.

[0043] Compared with the prior art, the beneficial effects of the present invention are:

[0044] 1. This reinforcement structure adopts a multi-layer composite structure system. It combines high-ductility ECC material with fiber mesh and steel fiber composite reinforcement, radial energy-dissipating ribs and shear keyways, and combines interfacial bonding, crack resistance and stress release capabilities to effectively inhibit the development of cracks in existing concrete components, improve the overall stiffness, ductility and shear performance of the structure, and at the same time, the layered structure adapts to the mechanical properties of the materials, which greatly extends the service life of the reinforcement system.

[0045] 2. By adopting an event-driven adaptive sampling method, the sampling mode can operate at low power consumption under normal conditions or collect data at abnormal high density, thus optimizing the operating energy consumption of the sensing element. Combined with edge computing technology and its improved adaptive threshold comparison algorithm, dynamic weighting factors and adaptive safety limits are introduced to dynamically correct the judgment deviation caused by environmental temperature and humidity and material aging. This not only enables long-term stable monitoring of the structural status, but also accurately identifies safety hazards, reduces the probability of false alarms and missed alarms, and realizes intelligent safety management and control of the entire life cycle of the reinforced structure. Attached Figure Description

[0046] Figure 1 A cross-sectional view of the pre-embedded sensing unit of the present invention;

[0047] Figure 2 This is a cross-sectional view of the main crack-resistant reinforcement layer of the present invention;

[0048] Figure 3 This is a cross-sectional view of the interface reinforcement layer of the present invention;

[0049] Figure 4 This is a top view of the main crack-resistant reinforcement layer and the interface enhancement layer of the present invention;

[0050] Figure 5 This is a diagram of the ECC chamfered corner reinforcement structure of the present invention.

[0051] In the diagram: 1. Base treatment layer; 11. Crack sealing section; 2. Interface reinforcement layer; 21. Low modulus flexible buffer layer; 22. High modulus rigid anchoring layer; 3. Main crack-resistant reinforcement layer; 31. Conventional section; 32. Reinforced section; 33. Low-energy-dissipation joint; 4. Surface protective layer; 5. ECC chamfered corner reinforcement structure; 6. Shear keyway; 7. Distributed fiber optic strain sensor; 8. Flexible crack sensing strip; 9. Temperature and humidity sensing probe; 10. Nodal strain sensing module. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] To address the shortcomings of existing mainstream building reinforcement methods, such as poor ductility, easy interface cracking and peeling, and stress concentration at joints, conventional high-ductility ECC reinforcement lacks layered structural optimization, has insufficient coordinated deformation performance, and a high recurrence rate of defects. Furthermore, traditional reinforcement systems generally lack routine intelligent sensing methods, relying solely on manual inspections, making it difficult to promptly detect hidden stress and deformation anomalies in weak areas of components, thus easily leaving structural safety hazards. Please refer to [link to relevant documentation]. Figure 1 - Figure 5 This embodiment provides the following technical solution:

[0054] A crack-resistant reinforcement structure for existing building structures based on high-ductility ECC is disclosed. This structure is applied to the outer surface of existing concrete structural members and includes, from the inside out, a base treatment layer 1, an interface reinforcement layer 2, a main crack-resistant reinforcement layer 3, and a surface protection layer 4. These structural layers work together to share the load, and specific reinforcement designs are implemented for weak points such as cracks and stress concentration points. This improves the overall crack resistance, load-bearing capacity, and long-term stability of existing concrete members from multiple dimensions, including base treatment, interface bonding, main reinforcement, local reinforcement, and surface protection. Specifically, during the construction of the base treatment layer 1, a mechanical roughening process is used to remove surface laitance, peeling, and loose, deteriorated concrete matrix, creating a rough, textured base surface. This rough surface significantly increases the contact area between subsequent structural layers and the original member, effectively improving the interlayer mechanical interlocking force and reducing the risk of hollowing and peeling of the reinforcement layer later. A crack sealing section 11 is provided in the base treatment layer 1 corresponding to the original component crack location. The crack sealing section 11 is a flexible sealant filled in the crack groove. The flexible sealant has good deformation ability and sealing performance. It can not only seal the internal pores of the crack and isolate the external water vapor and corrosive media from entering the crack, thus preventing the original crack from continuing to expand and extend under the action of the external environment, but also adapt to the small deformation displacement of the crack location, preventing the rigid sealing material from cracking and failing due to the micro deformation of the component, thus achieving long-term sealing treatment of the original crack. The interface reinforcement layer 2 adopts a modulus gradient double-layer structure, consisting of an inner low-modulus flexible buffer layer 21 and an outer high-modulus rigid anchoring layer 22. The low-modulus flexible buffer layer 21 has excellent deformation adaptability, which can buffer the deformation difference between the original concrete component and the outer reinforcement structure caused by material modulus difference, load action, and temperature change, effectively release interlayer additional stress, and prevent cracking at the interface between the new and old structures. The outer high-modulus rigid anchoring layer 22 has high structural strength and stiffness, which can stably transmit the upper load and ensure the continuity and reliability of the overall force transmission path. At the same time, micro-dimples or serrated interlocking structures are processed on the outer surface of the high-modulus rigid anchoring layer 22 to further enhance the mechanical interlocking effect between the interface reinforcement layer 2 and the main crack-resistant reinforcement layer 3, solving the drawbacks of easy cracking and interlayer separation at the interface between the new and old in traditional reinforcement processes.The main crack-resistant reinforcement layer 3 is made of high-ductility ECC material. High-ductility ECC material possesses characteristics such as ultra-high tensile strength, multi-crack energy dissipation, crack self-healing, and excellent ductility, distinguishing it from traditional reinforcement materials such as ordinary concrete and repair mortar. It can significantly improve the crack resistance and deformation coordination of the reinforcement system. Based on the stress state of different areas of the component, the main crack-resistant reinforcement layer 3 is divided into a conventional section 31 and a reinforced section 32 corresponding to the cracks in the original component. This section covers most of the component, primarily bearing the overall load and uniformly transferring the internal forces of the structure, ensuring the overall stiffness and stability of the component. The reinforced section 32 corresponds to the area where the cracks in the original component are located, which is a locally weak stress area. Section 32 is internally reinforced with a composite of fiber mesh and steel fiber with beveled edges. The beveled edge structure can eliminate stress concentration at the ends of the reinforcement. The fiber mesh and steel fiber work together to further improve local tensile, crack and impact resistance, effectively restraining the re-propagation of original cracks. Micro-energy dissipation joints 33 are preset according to the stress direction of the component, and the joints are filled with flexible sealing material. The micro-energy dissipation joints 33 can actively release the internal stress of the reinforcement layer caused by temperature changes and material shrinkage, avoiding shrinkage cracks and temperature cracks in the main crack-resistant reinforcement layer 3 itself. The flexible sealing material ensures the sealing and deformation capacity of the joint, taking into account both stress release and overall protection. At the corners of the structural members and stress concentration points at beam-column joints, an ECC chamfered corner reinforcement structure 5 with radial energy-dissipating ribs is integrated with the main crack-resistant reinforcement layer 3, forming a complete whole to ensure continuous force transmission. The radial structure on the outside of the ECC chamfered corner reinforcement structure 5 can disperse and dissipate concentrated stress at the joints and corners in multiple directions, significantly alleviating local stress concentration problems and improving the crack resistance and damage resistance of key joints of the structural members. At the same time, the interface between the ECC chamfered corner reinforcement structure 5 and the original structural member is provided with a shear keyway 6. The keyway structure further enhances the shear resistance and embedding effect of the interface, preventing slippage and separation at corners and joints under repeated loading, and strengthening the structural reliability of key weak points. The outermost sides of the main crack-resistant reinforcement layer 3 and the ECC chamfered corner reinforcement structure 5 are uniformly provided with a surface protective layer 4. The surface protective layer 4 can isolate the internal high-ductility ECC reinforcement system from external rainwater, moisture, atmospheric corrosive media and ultraviolet rays, delay the aging rate of materials, protect the internal reinforcement structure to work stably for a long time, and further extend the service life of the entire reinforcement structure.

[0055] The beneficial effects achieved by the above content are as follows: This reinforcement structure adopts a multi-layer composite structure system. Through the combination of high-ductility ECC material with fiber mesh and steel fiber composite reinforcement, radial energy dissipation ribs and shear keyways, combined with interfacial bonding, crack resistance and stress release capabilities, it can effectively inhibit the development of cracks in existing concrete components, improve the overall stiffness, ductility and shear performance of the structure, and at the same time, the layered structure adapts to the mechanical properties of the materials, which greatly extends the service life of the reinforcement system.

[0056] The reinforced structure also integrates an intelligent monitoring system, which includes:

[0057] The pre-embedded sensing unit consists of a distributed fiber optic strain sensor 7, a flexible crack sensing strip 8, a temperature and humidity sensing probe 9, and a node strain sensing module 10. The distributed fiber optic strain sensor 7 is laid out along the entire length of the main crack-resistant reinforcement layer 3. The flexible crack sensing strip 8 is placed in the crack area of ​​the original component and around the micro-energy-dissipating joint 33. The temperature and humidity sensing probe 9 is dispersedly placed inside the main crack-resistant reinforcement layer 3. The node strain sensing module 10 is placed in the core stress-bearing part of the beam-column joint reinforcement area, and a flame-retardant protective sleeve is fitted outside the sensing lines. The configuration is to collect data through a preset sampling frequency. The distributed fiber optic strain sensor 7 collects the overall strain distribution data of the main crack-resistant reinforcement layer 3 and the component body in real time. The temperature and humidity sensing probe 9 monitors the crack width change and joint displacement development. The node strain sensing module 10 monitors the stress mutation and strain concentration in the node area. Specifically:

[0058] The distributed fiber optic strain sensor 7 collects strain distribution data according to a preset first sampling frequency. The flexible crack sensing strip 8, temperature and humidity sensing probe 9, and nodal strain sensing module 10 operate synchronously in a low-power standby mode, retaining only data reception and trigger response functions. The first sampling frequency is the normal monitoring sampling frequency, which is preset based on the characteristics of slow deformation development of building structures under long-term service and conventional loads. The value standard is set in accordance with the general specifications for monitoring the reinforcement of civil buildings, and the normal value range is 0.5Hz to 2Hz, which is suitable for components under daily static loads, temperature creep, and other conditions with gradual changes. While ensuring the effectiveness of basic monitoring, the power consumption of sensing elements and terminal equipment is reduced to the minimum, and the overall equipment endurance is extended.

[0059] When the rate of change of strain data calculated in real time by the local acquisition terminal is greater than the preset rate of change threshold, it is marked as an abnormal event and an abnormal signal is immediately output; the distributed fiber optic strain sensor 7, flexible crack sensing strip 8, temperature and humidity sensing probe 9 and nodal strain sensing module 10 are simultaneously triggered to switch to the preset second sampling frequency and acquire data synchronously with the distributed fiber optic strain sensor 7.

[0060] The second sampling frequency is higher than the first sampling frequency. The second sampling frequency is the encrypted sampling frequency for abnormal working conditions. It is preset based on the short-term dynamic change characteristics such as sudden load on the structure, sudden change in local stress, and rapid crack propagation. The value standard is set according to the needs of capturing the dynamic response of the structure. The normal value range is 20Hz to 100Hz. This frequency can completely capture the dynamic processes such as instantaneous deformation of components, crack expansion, and stress fluctuation at nodes, avoid the loss of high-frequency change signals, and ensure the integrity of data under abnormal conditions.

[0061] When the strain data change rate calculated in real time by the local acquisition terminal is within the preset change rate threshold and is maintained for a preset stable time, the control of each sensing element in the pre-embedded sensing unit switches back to the initial normal acquisition mode, and the flexible crack sensing strip 8, temperature and humidity sensing probe 9, and nodal strain sensing module 10 re-enter the low power standby state and repeat the above steps.

[0062] When the strain data change rate calculated in real time by the local acquisition terminal exceeds the preset change rate threshold, a preset time window before and after the trigger time is used to define the start time period of the abnormal event; all raw data output by all sensing elements within this time window are automatically captured, and the data sequence within this time period is marked as key data of the abnormal event; the marked key data sequence is divided into independent storage partitions for archiving and saving; and the acquisition time, sampling frequency and trigger type and other auxiliary information corresponding to the data are recorded simultaneously, so as to completely retain the time-series change log of the component stress, cracks and environmental parameters.

[0063] The distributed fiber optic strain sensor 7, flexible crack sensing strip 8, and temperature and humidity sensing probe 9 employ wired transmission. The inherent properties of optical fiber are unaffected by shielding from concrete or ECC materials. The optical signal is transmitted within the fiber core, and concrete, cement-based materials, and reinforcing steel do not interfere with the signal, resulting in extremely low signal attenuation and stable transmission. The cable is encased in a flame-retardant protective sleeve and connected to an external local acquisition terminal via wired connection. The signal is transmitted along the conductor, avoiding the problem of wires penetrating shielding. The distributed fiber optic strain sensor 7, flexible crack sensing strip 8, and temperature and humidity sensing probe 9 utilize a combination of solar energy storage batteries and backup industrial-grade batteries for power supply. The industrial-grade batteries support continuous operation for 7-15 days without recharging, addressing short-term power outages and continuous rainy weather. Depending on site conditions, a low-voltage DC mains power conversion module can be added to the external equipment area of ​​the components and connected in parallel with the solar energy storage battery. Under normal operating conditions, solar power is prioritized, while mains power remains in standby mode. When solar power is insufficient or the battery is depleted, the system automatically switches to mains power.

[0064] An external data early warning unit is configured to receive and aggregate real-time data collected by the pre-embedded sensing unit via a local acquisition terminal. Based on a built-in edge computing module, it employs an improved adaptive threshold comparison algorithm to compare the real-time data with preset safety limits and stores the data locally. When the collected data exceeds the preset safety limits, an audible and visual early warning device is triggered to issue an audible and visual alarm, and alarm information is simultaneously pushed to a remote platform via wired transmission technology. The external data early warning unit is fixed in a concealed location on the original component and electrically connected to the pre-embedded sensing unit. Specifically:

[0065] A data interaction channel with the pre-embedded sensing unit is established based on wired communication technology. Within each sampling period, the system synchronously reads the measured data output by the sensing unit, real-time ambient temperature, real-time ambient humidity, and the cumulative service time of the component after self-reinforcement in historical records. Preset benchmark safety limits, temperature and humidity reference values, service time benchmark values, various correction coefficients, and deviation judgment thresholds are loaded. Based on the collected real-time data and initialization parameters, a dynamic weighting factor and an adaptive safety limit mechanism are introduced to calculate the standardized relative deviation value. The calculation formula is as follows:

[0066]

[0067] In the formula, Represented as Standardized relative deviation at time; Represented as Measured data collected by the time-sensing unit; Represented as the component's baseline safety limit; This represents the initial baseline value of the dynamic deviation weighting factor; This is expressed as the temperature and humidity coupling attenuation coefficient; This is expressed as the temperature and humidity coupling difference. This is expressed as a temperature influence coefficient; This is expressed as the humidity influence coefficient; Expressed as a relative change in temperature; Expressed as a relative change in humidity; This is expressed as the component aging correction factor; This represents the cumulative service life of the component since the reinforcement was completed. This is represented as a reference value for service duration.

[0068] The standardized relative deviation value obtained from the calculation is compared with the preset deviation judgment threshold. If the standardized relative deviation value is less than the deviation judgment threshold range, the component is determined to be operating normally, and the process waits for the next sampling cycle and repeats the above process. If the standardized relative deviation value is greater than the deviation judgment threshold range, the monitoring data is determined to be out of limit, an alarm command is immediately issued to the audible and visual warning device, and the alarm information and all calculated data for the current period are pushed to the remote management platform through wired transmission technology. The above steps are repeated continuously according to the sampling cycle, and the safety comparison benchmark is dynamically adjusted according to the formula to achieve adaptive threshold comparison under all working conditions.

[0069] The beneficial effects achieved by the above are as follows: By adopting an event-driven adaptive sampling method, the sampling mode can operate at low power consumption under normal conditions, and can also collect data at abnormally high density, thus optimizing the operating energy consumption of the sensing elements; combined with edge computing technology and its improved adaptive threshold comparison algorithm, dynamic weighting factors and adaptive safety limits are introduced to dynamically correct the judgment deviation caused by environmental temperature and humidity and material aging. This not only enables long-term stable monitoring of the structural status, but also accurately identifies safety hazards, reduces the probability of false alarms and missed alarms, and realizes intelligent safety management and control of the entire life cycle of the reinforced structure.

[0070] A method for implementing crack-resistant reinforcement of existing building structures based on high-ductility ECC includes the following steps:

[0071] S1: Roughen the outer surface of the existing concrete structural member, remove loose concrete, and form a base treatment layer 1; and groove the original cracks of the member, and fill the grooves with flexible sealant to form crack sealing sections 11.

[0072] S2: A low-modulus flexible buffer layer 21 and a high-modulus rigid anchoring layer 22 are sequentially applied on the outside of the base treatment layer 1 to form an interface reinforcement layer 2 with a modulus gradient double-layer structure, and a micro-dimple or serrated interlocking structure is formed on the surface of the high-modulus rigid anchoring layer 22.

[0073] S3: Distributed fiber optic strain sensors 7 are laid out along the main crack-resistant reinforcement layer 3 according to the preset points, flexible crack sensing strips 8 are laid out in the crack area of ​​the component and around the micro-energy-consuming joint 33, temperature and humidity sensing probes 9 are dispersed inside the main crack-resistant reinforcement layer 3, and nodal strain sensing modules 10 are laid out at the core stress part of the beam-column joint.

[0074] S4: The main crack-resistant reinforcement layer 3 is cast in sections using high-ductility ECC material, forming a conventional section 31 and a reinforced section 32 corresponding to the cracks in the component. A fiber mesh with beveled edges and a steel fiber composite reinforcement are embedded in the reinforced section 32. Micro-energy-dissipating joints 33 are set in the main crack-resistant reinforcement layer 3 along the stress direction of the component, and the joints are filled with flexible sealing material.

[0075] S5: At the corners of the components and the stress concentration points of the beam-column joints, an ECC chamfered corner reinforcement structure 5 with radial energy dissipation ribs is integrally cast with the main crack-resistant reinforcement layer 3, and a shear keyway 6 is opened on the interface between the ECC chamfered corner reinforcement structure 5 and the original component.

[0076] S6: Apply a surface protective layer 4 to the outside of the main crack-resistant reinforcement layer 3 and the ECC chamfered corner reinforcement structure 5;

[0077] S7: The reinforced structure after construction shall be cured in accordance with the curing requirements of high ductility ECC materials until the overall strength reaches the design standard;

[0078] S8: Install an external data early warning unit in a concealed location on the original component, electrically connect the external data early warning unit to the pre-embedded sensing unit, and perform insulation and waterproof protection treatment on the connection line;

[0079] S9: Power on the intelligent monitoring system for self-test, input the benchmark safety limit, temperature and humidity reference values, various correction coefficients, sampling frequency, judgment threshold and other operating parameters, and after completing the debugging of the acquisition logic and threshold comparison algorithm, put it into normal use.

[0080] Working principle: A multi-layer composite system is formed by a roughened and sealed base treatment layer 1, an interface reinforcement layer 2, a high-ductility ECC main crack-resistant reinforcement layer 3 containing composite reinforcement and micro-energy-dissipating joints 33, and a surface protective layer 4. Combined with an ECC chamfered corner reinforcement structure 5 with radial energy-dissipating ribs and a shear-resistant keyway 6 at the interface, reliable force transfer, stress dispersion, and crack suppression between layers are achieved, comprehensively improving the load-bearing, crack resistance, and shear resistance of existing concrete components. At the same time, by pre-embedding multiple types of sensors in conjunction with an external data early warning unit, data is collected using an event-driven adaptive sampling mode. Relying on an improved threshold comparison algorithm incorporating dynamic weighting factors and adaptive safety limits, combined with dynamic correction criteria based on environmental temperature and humidity and component service life, the system accurately identifies abnormal structural states and simultaneously issues audible, visual, and remote alarms, ultimately achieving an organic combination of component reinforcement and intelligent monitoring and early warning throughout the entire life cycle.

[0081] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or article that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or article.

[0082] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A crack-resistant reinforcement structure for existing building structures based on high-ductility ECC, installed on the outer surface of existing concrete structural members, characterized in that, include: The base treatment layer (1), interface reinforcement layer (2), main crack-resistant reinforcement layer (3) and surface protection layer (4) are arranged sequentially from the inside to the outside. The main crack-resistant reinforcement layer (3) includes a conventional section (31) and a reinforced section (32) corresponding to the cracks in the original component. The reinforced section (32) is embedded with a fiber mesh + steel fiber composite reinforcement with a chamfered edge. The corners of the component and the stress concentration positions of the beam-column joints are provided with an ECC chamfered corner reinforcement structure (5) with radial energy dissipation ribs that is integrated with the main crack-resistant reinforcement layer (3). The ECC chamfered corner reinforcement structure (5) and the original component are provided with a shear keyway (6). The reinforced structure also integrates an intelligent monitoring system, which includes: The pre-embedded sensing unit consists of a distributed fiber optic strain sensor (7), a flexible crack sensing strip (8), a temperature and humidity sensing probe (9), and a node strain sensing module (10). It is configured to collect data through a preset sampling frequency. The distributed fiber optic strain sensor (7) collects the overall strain distribution data of the main crack-resistant reinforcement layer (3) and the component body in real time. The temperature and humidity sensing probe (9) monitors the crack width change and the development of the crack displacement. The node strain sensing module (10) monitors the stress change and strain concentration in the node area. The external data early warning unit is configured to receive and aggregate real-time data collected by the pre-embedded sensor unit through a local acquisition terminal. Based on the built-in edge computing module, an improved adaptive threshold comparison algorithm is used to compare the real-time data with the preset safety limit. When the collected data exceeds the preset safety limit, the audible and visual warning device is triggered to issue an audible and visual alarm, and alarm information is simultaneously pushed to the remote platform based on wired transmission technology.

2. The existing building structure crack-resistant reinforcement structure based on high ductility ECC according to claim 1, characterized in that, The external data early warning unit, based on the built-in edge computing module, employs an improved adaptive threshold comparison algorithm to compare real-time data with preset safety limits. Specifically: A data interaction channel with the pre-embedded sensing unit is established based on wired communication technology. In each sampling period, the measured data output by the sensing unit, real-time ambient temperature, real-time ambient humidity, and the cumulative service time of the component after self-reinforcement in the historical records are read synchronously. Load the preset baseline safety limits, temperature and humidity reference values, service duration baseline values, various correction coefficients, and deviation judgment thresholds; Based on the collected real-time data and initialization parameters, a dynamic weighting factor and an adaptive safety limit mechanism are introduced to calculate the standardized relative deviation value. The standardized relative deviation value obtained by calculation is compared with the preset deviation judgment threshold. If the standardized relative deviation value is less than the deviation judgment threshold, the component is judged to be in normal operating condition, and the process is repeated for the next sampling period. If the standardized relative deviation value is greater than the deviation judgment threshold range, the monitoring data is judged to be out of limit, an alarm command is immediately issued to the audible and visual early warning device, and the alarm information and all current calculation data are pushed to the remote management platform through wired transmission technology.

3. The existing building structure crack-resistant reinforcement structure based on high ductility ECC according to claim 2, characterized in that, By introducing a dynamic weighting factor and an adaptive safety limit mechanism, the standardized relative deviation value is calculated using the following formula: ； In the formula, Represented as Standardized relative deviation at time; Represented as Measured data collected by the time-sensing unit; Represented as the component's baseline safety limit; This represents the initial baseline value of the dynamic deviation weighting factor; This is expressed as the temperature and humidity coupling attenuation coefficient; This is expressed as the temperature and humidity coupling difference. This is expressed as a temperature influence coefficient; This is expressed as the humidity influence coefficient; Expressed as a relative change in temperature; Expressed as a relative change in humidity; This is expressed as the component aging correction factor; This represents the cumulative service life of the component since the reinforcement was completed. This is represented as a reference value for service duration.

4. The existing building structure crack-resistant reinforcement structure based on high ductility ECC according to claim 1, characterized in that, The pre-embedded sensing unit acquires data through a preset sampling frequency, specifically as follows: The distributed fiber optic strain sensor (7) collects strain distribution data according to the preset first sampling frequency. The flexible crack sensing strip (8), temperature and humidity sensing probe (9) and nodal strain sensing module (10) operate synchronously in low-power standby mode. When the rate of change of strain data calculated in real time by the local acquisition terminal exceeds the preset rate of change threshold, it is marked as an abnormal event and an abnormal signal is immediately output. The distributed fiber optic strain sensor (7), flexible crack sensing strip (8), temperature and humidity sensing probe (9) and nodal strain sensing module (10) are simultaneously triggered to switch to the preset second sampling frequency and acquire data synchronously with the distributed fiber optic strain sensor (7). The second sampling frequency is higher than the first sampling frequency; When the strain data change rate calculated in real time by the local acquisition terminal is within the preset change rate threshold and continues to maintain a preset stable duration, the control unit switches each sensing element in the embedded sensing unit back to the initial normal acquisition mode.

5. The existing building structure crack-resistant reinforcement structure based on high ductility ECC according to claim 4, characterized in that, When the rate of change of strain data calculated in real time by the local acquisition terminal is greater than the preset rate of change threshold, the start time period of the abnormal event is defined by the preset time window before and after the trigger time. Automatically capture all raw data output by all sensing elements within the time window, and mark the data sequence within this time period as key data of abnormal events; The marked key data sequences are divided into independent storage partitions for archiving and preservation; and the acquisition time, sampling frequency and trigger type of the data are recorded synchronously to completely preserve the time-series change log of the component's stress, cracks and environmental parameters.

6. The existing building structure crack-resistant reinforcement structure based on high ductility ECC according to claim 1, characterized in that, The base treatment layer (1) is a rough base surface formed after the surface of the component is roughened and loose concrete is removed. The base treatment layer (1) is provided with a crack sealing section (11) corresponding to the original component crack position. The crack sealing section (11) is a flexible sealant filled in the crack groove.

7. The existing building structure crack-resistant reinforcement structure based on high ductility ECC according to claim 1, characterized in that, The interface enhancement layer (2) is a modulus gradient double-layer structure, consisting of an inner low-modulus flexible buffer layer (21) and an outer high-modulus rigid anchoring layer (22). The surface of the high-modulus rigid anchoring layer (22) has a micro-dimple / serrated interlocking structure.

8. The existing building structure crack-resistant reinforcement structure based on high ductility ECC according to claim 1, characterized in that, The main crack-resistant reinforcement layer (3) is made of high-ductility ECC material, and micro-energy-dissipating joints (33) are preset according to the stress direction of the component, and the joints are filled with flexible sealing material.

9. The crack-resistant reinforcement structure for existing building structures based on high-ductility ECC according to claim 1, characterized in that, The distributed fiber optic strain sensor (7) is laid out along the main crack-resistant reinforcement layer (3). The flexible crack sensing strip (8) is laid out around the crack area of ​​the original component and the micro-energy-consuming joint (33). The temperature and humidity sensing probe (9) is dispersed inside the main crack-resistant reinforcement layer (3). The node strain sensing module (10) is laid out in the core stress part of the beam-column joint reinforcement area and is covered with a flame-retardant protective sleeve outside the sensing line.

10. A method for implementing a crack-resistant reinforcement structure for existing building structures based on high-ductility ECC, applied to the crack-resistant reinforcement structure for existing building structures based on high-ductility ECC as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Roughen the outer surface of the existing concrete structural member to form a base treatment layer (1); and groove the original cracks of the member and fill the grooves with flexible sealant to form crack sealing sections (11). S2: A low-modulus flexible buffer layer (21) and a high-modulus rigid anchoring layer (22) are sequentially applied on the outside of the base treatment layer (1) to form an interface reinforcement layer (2) with a modulus gradient double-layer structure. S3: Distributed fiber optic strain sensors (7) are laid out along the main crack-resistant reinforcement layer (3) according to the preset points. Flexible crack sensing strips (8) are laid out around the crack area of ​​the component and the micro-energy-consuming joint (33). Temperature and humidity sensing probes (9) are dispersed inside the main crack-resistant reinforcement layer (3). Nodal strain sensing modules (10) are laid out at the core stress part of the beam-column joint. S4: The main crack-resistant reinforcement layer (3) is cast in sections using high-ductility ECC material, forming a conventional section (31) and a reinforced section (32) for the corresponding component cracks. A fiber mesh with beveled edges and a steel fiber composite reinforcement are embedded in the reinforced section (32). Micro-energy-dissipating joints (33) are set in the main crack-resistant reinforcement layer (3) along the force direction of the component, and flexible sealing material is filled in the joints. S5: At the corner of the component and the stress concentration position of the beam-column joint, an ECC chamfered corner reinforcement structure (5) with radial energy dissipation ribs is integrally cast with the main crack-resistant reinforcement layer (3), and a shear keyway (6) is opened on the joint surface between the ECC chamfered corner reinforcement structure (5) and the original component. S6: An overall surface protective layer (4) is constructed on the outside of the main crack-resistant reinforcement layer (3) and the ECC chamfered corner reinforcement structure (5); S7: The reinforced structure after construction shall be cured in accordance with the curing requirements of high ductility ECC materials until the overall strength reaches the design standard; S8: Install an external data early warning unit in a concealed location on the original component, electrically connect the external data early warning unit to the pre-embedded sensing unit, and perform insulation and waterproof protection treatment on the connection line; S9: Power on the intelligent monitoring system for self-test, input the benchmark safety limit, temperature and humidity reference values, various correction coefficients, sampling frequency, judgment threshold and other operating parameters, and after completing the debugging of the acquisition logic and threshold comparison algorithm, put it into normal use.

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