Concrete anti-cracking method and system based on fiber reinforcement

Abstract

The invention discloses a concrete anti-cracking method and system based on fiber reinforcement, and belongs to the technical field of concrete anti-cracking. The method comprises the following steps: acquiring real-time strain data in concrete through a distributed optical fiber sensor; analyzing the data to obtain a three-dimensional crack propagation path containing a crack initiation position, a propagation angle and a tip position; identifying the dominant development direction of the crack and a fan-shaped potential expansion interval which extends at an expansion angle by taking the tip as a vertex based on the path data; in the potential expansion interval of the to-be-poured area, a fiber distribution layer arranged in the dominant development direction is formed through directional arrangement equipment; and the fiber-reinforced anti-cracking structure is formed through vibrating and compacting treatment. According to the invention, directional blocking of fibers to crack expansion is realized, the problem of disordered expansion of cracks is effectively solved, and the anti-cracking efficiency of concrete is improved.

Description

Technical Field

[0001] This invention relates to the field of concrete crack resistance technology, and in particular to a method and system for concrete crack resistance based on fiber reinforcement. Background Technology

[0002] In concrete structural engineering, the generation and propagation of cracks are critical issues affecting structural safety and durability. Traditional concrete crack-resistant technologies rely heavily on surface observation or point sensors for crack monitoring, which can only acquire localized, two-dimensional crack information. This fails to capture the initiation location, propagation angle, and tip position of internal cracks, making it difficult to generate complete three-dimensional crack propagation path data. The limitations of this monitoring method lead to significant deviations in judging the dominant direction of crack development and potential propagation range, thus failing to provide accurate guidance for crack-resistant measures.

[0003] Meanwhile, in existing fiber-reinforced technologies, fibers are often randomly distributed in concrete, and their arrangement direction lacks targeted matching with the crack propagation path. When cracks propagate disorderly along a specific direction, the randomly distributed fibers are unable to form an effective barrier, resulting in poor crack resistance. Furthermore, due to the inability to accurately predict crack propagation trends, fiber materials are often overused or misplaced, increasing costs and failing to prevent the continued propagation of cracks, severely impacting the service life of concrete structures. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, embodiments of the present invention provide a fiber-reinforced concrete crack-resistant method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides a method for crack resistance of fiber-reinforced concrete, comprising: Real-time strain data of concrete under stress and shrinkage is collected by distributed fiber optic sensors embedded in the concrete and deployed along a preset monitoring section. Spatiotemporal feature analysis was performed on the real-time strain data to obtain three-dimensional crack propagation path data including crack initiation location, propagation angle, and tip location; Based on the three-dimensional crack propagation path data, the dominant development direction and potential propagation range of the crack are identified, wherein the potential propagation range is a fan-shaped region extending along the propagation angle with the tip position as the vertex. Within the potential expansion zone of the concrete pouring area, a fiber-oriented distribution layer arranged along the dominant development direction is formed by a fiber-oriented placement device; The concrete area to be poured, where the fiber-directed distribution layer is located, is compacted by vibration to form a fiber-reinforced, crack-resistant concrete structure.

[0006] To address the above problems, the present invention also provides a fiber-reinforced concrete crack-resistant system, the system comprising: The real-time strain data acquisition module is used to acquire real-time strain data of concrete under stress and shrinkage by using distributed fiber optic sensors embedded in the concrete and deployed along a preset monitoring section. The three-dimensional crack propagation path analysis module is used to perform spatiotemporal feature analysis on the real-time strain data to obtain three-dimensional crack propagation path data including crack initiation location, propagation angle, and tip location. The crack development direction and interval identification module is used to identify the dominant development direction and potential extension interval of the crack based on the three-dimensional crack propagation path data, wherein the potential extension interval is a fan-shaped region extending along the propagation angle with the tip position as the vertex. A fiber-oriented distribution layer deployment module is used to form a fiber-oriented distribution layer arranged along the dominant development direction within the potential expansion range of the concrete pouring area using a fiber-oriented deployment device. A fiber-reinforced concrete crack-resistant structure forming module is used to vibrate and compact the concrete area to be poured where the fiber-directed distribution layer is located, thereby forming a fiber-reinforced concrete crack-resistant structure.

[0007] This invention utilizes distributed fiber optic sensors embedded within concrete to collect real-time strain data along multi-dimensional preset monitoring sections. Through spatiotemporal feature analysis, it accurately obtains three-dimensional crack propagation path data, including crack initiation location, propagation angle, and tip position. This overcomes the limitations of traditional monitoring methods in capturing insufficient three-dimensional information within cracks, providing precise spatial coordinates and directional guidance for fiber directional placement. Based on the three-dimensional crack propagation path data, curve fitting and trend analysis accurately identify the dominant crack development direction and the fan-shaped potential propagation range with the tip position as the apex, achieving accurate prediction of crack propagation trends. Furthermore, a fiber directional placement device forms a fiber-oriented distribution layer along the dominant development direction within the potential propagation range, ensuring a high degree of match between the fiber arrangement direction and the crack propagation path. Combined with targeted vibration compaction, this ensures a tight bond between the fibers and the concrete matrix. This directional placement method significantly improves the fiber's efficiency in blocking crack propagation, solves the problem of insufficient crack resistance caused by the random distribution of traditional fibers, effectively suppresses disordered crack propagation, and thus improves the crack resistance of concrete structures. Attached Figure Description

[0008] Figure 1 This is a schematic flowchart of a fiber-reinforced concrete crack-resistant method according to an embodiment of the present invention. Figure 2 A functional block diagram of a fiber-reinforced concrete crack-resistant system provided in an embodiment of the present invention; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0009] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0010] This application provides a fiber-reinforced concrete crack-resistant method. The execution entity of the fiber-reinforced concrete crack-resistant method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the fiber-reinforced concrete crack-resistant method can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster. The server can be an independent server or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks, and big data and artificial intelligence platforms.

[0011] Reference Figure 1 The diagram shown is a flowchart illustrating a fiber-reinforced concrete crack-resistant method according to an embodiment of the present invention.

[0012] The implementation of this method is divided into two stages: the learning and analysis stage and the application and construction stage.

[0013] During the learning and analysis phase, a representative pilot test specimen (such as a full-scale model) or a similar structural segment constructed earlier is selected, and a distributed fiber optic sensor network is pre-embedded within it. Through long-term monitoring of the structure under load, temperature changes, shrinkage, and other effects, real data on crack initiation and propagation are obtained.

[0014] During the application and construction phase, the crack propagation patterns (including three-dimensional paths, dominant directions, and potential regions) obtained from the learning phase analysis are applied to newly constructed target structures with the same or similar designs. Before pouring concrete into the target structure, oriented fiber layers are precisely placed in the corresponding areas to be poured based on the predicted crack information, thereby achieving crack resistance.

[0015] In this embodiment, the fiber-reinforced concrete crack-resistant method includes: S1. Real-time strain data of concrete under stress and shrinkage is collected by distributed fiber optic sensors embedded in the concrete and deployed along a preset monitoring section.

[0016] In this embodiment, a distributed optical fiber sensor is a device capable of measuring or monitoring spatially distributed and time-varying information along an optical fiber transmission path. Its working principle involves simultaneously utilizing the optical fiber as both the sensing element and the signal transmission medium, employing optical time-domain reflectometry (OTDR) and optical frequency-domain reflectometry (FDR) techniques to detect changes in temperature and strain at different locations along the optical fiber, thereby achieving truly distributed measurement. For example, in the monitoring of large building structures, distributed optical fiber sensors can be used to monitor the stress, strain, and temperature of the structure in real time.

[0017] In some embodiments, the preset monitoring section includes: a longitudinal section spaced apart along the length of the concrete structure, a transverse section along the width direction, and a vertical section along the height direction.

[0018] In this embodiment, the preset monitoring sections are sections set up to comprehensively acquire the internal strain of the concrete. These include longitudinal sections spaced along the length of the concrete structure, transverse sections along the width, and vertical sections along the height. This arrangement aims to capture strain information of the concrete in different directions from multiple dimensions, thereby providing a more comprehensive understanding of the internal strain state of the concrete. Taking a concrete structure 10 meters long, 5 meters wide, and 3 meters high as an example, longitudinal sections can be set every 1 meter, transverse sections can be set at the midpoint of the width, and vertical sections can be set at the midpoint of the height. This method can comprehensively cover the internal space of the concrete structure.

[0019] In some embodiments, the real-time strain data includes: axial strain, radial strain, and shear strain, wherein: the axial strain is determined based on the elongation performance index of the concrete structure; the radial strain is determined based on the expansion properties of the concrete structure in the width direction; and the shear strain is used to correlate with external data resources on the stress state of the concrete structure.

[0020] In this embodiment, real-time strain data refers to the strain of concrete at different times under stress and shrinkage, including axial strain, radial strain, and shear strain. Axial strain is determined based on the expansion and contraction performance index of the concrete structure in the length direction, reflecting the deformation of the concrete in the length direction. Radial strain is determined based on the expansion property of the concrete structure in the width direction, reflecting the change of the concrete in the width direction. Shear strain is used to correlate with external data resources of the stress state of the concrete structure, which helps to understand the stress state inside the concrete.

[0021] First, based on the size and shape of the concrete structure, plan the location and number of pre-set monitoring sections. For example, for a concrete beam that is 10 meters long, 5 meters wide, and 3 meters high, a longitudinal section can be set every 1 meter, a transverse section can be set at the midpoint of the width (2.5 meters), and a vertical section can be set at the midpoint of the height (1.5 meters).

[0022] Then, the distributed fiber optic sensors are embedded and installed according to the pre-planned monitoring cross-section to ensure that the sensors can accurately detect strain changes inside the concrete. During installation, it is essential to ensure that the fiber optic cables of the sensors are tightly bonded to the concrete to prevent loosening or detachment.

[0023] Next, connect both ends of the distributed optical fiber sensor to the demodulator. The demodulator converts the optical signals collected by the sensor into digital signals for subsequent data processing and analysis.

[0024] Finally, the demodulator transmits the converted digital signal to the data server for storage and management. The data server stores the data in the format of timestamps plus three-dimensional coordinates (x, y, z) as well as axial strain, radial strain, and shear strain, which is convenient for subsequent retrieval and analysis.

[0025] In this embodiment, axial strain is the strain generated when a concrete structure undergoes expansion and contraction along its length. Its determination requires consideration of the expansion and contraction performance index of the concrete structure along its length. This index is typically obtained through material testing. For example, the expansion and contraction performance index of a C30 concrete beam is 1.2 × 10⁻⁶ mm² under standard curing conditions, with a length expansion rate of 1.2 × 10⁻⁶ mm² for every 1°C change in temperature. -5 In actual monitoring, when distributed fiber optic sensors collect strain data along the length direction, it is compared with the expansion and contraction performance index. If the strain value is within the reasonable range corresponding to the index, it is determined to be axial strain. For example, when the ambient temperature rises by 10℃, the theoretical expansion and contraction strain can be calculated to be 1.2 × 10⁻⁶ based on the expansion and contraction performance index. -4 If the strain along the length direction collected by the sensor is 1.18 × 10⁻⁶ -4 This can be identified as axial strain.

[0026] In this embodiment, radial strain is the strain generated when a concrete structure undergoes expansion or contraction deformation in the width direction. It is determined based on the expansion properties of the concrete structure in the width direction, which are also determined experimentally. For example, the expansion coefficient of the C30 concrete beam in the width direction is 0.8 × 10⁻⁶ when the internal humidity changes by 10%. -5During monitoring, the strain data in the width direction is compared with this expansion property. If the strain conforms to the change pattern corresponding to the expansion property, it is determined to be radial strain. For example, when the internal humidity of concrete increases by 20%, the theoretical expansion strain should be 1.6 × 10⁻⁶. -4 If the strain in the width direction collected by the sensor is 1.58 × 10⁻⁶ -4 This can be determined as radial strain.

[0027] In this embodiment, shear strain is the strain that reflects the tendency of relative displacement between different parts within a concrete structure. It is used to correlate external data resources related to the stress state of the concrete structure, including lateral forces and torques acting on the structure. For example, when a concrete beam is subjected to lateral thrust, an internal shear tendency is generated; the strain reflecting this displacement tendency, collected by distributed fiber optic sensors, is the shear strain. By correlating shear strain data with external stress data (such as a lateral force of 50 kN), a more comprehensive understanding of the structure's stress state can be obtained, providing a basis for determining whether cracks are caused by shear force.

[0028] In this embodiment, step S1 can overcome the problem of limited monitoring range of traditional point sensors, and realize all-round and real-time capture of internal strain of concrete, providing a comprehensive and accurate data foundation for subsequent accurate identification of cracks.

[0029] S2. Perform spatiotemporal feature analysis on the real-time strain data to obtain three-dimensional crack propagation path data including crack initiation location, propagation angle, and tip location.

[0030] In this embodiment, spatiotemporal feature analysis is a process of analyzing the characteristics of internal cracks in concrete by combining the changes in real-time strain data over time and the differences in their spatial distribution. The crack initiation location is the location where the first strain abrupt change occurs inside the concrete, which is where the crack begins to form. The propagation angle is the angle formed between the crack's propagation direction in space and the preset monitoring section, used to describe the direction of crack extension. The tip location is the furthest point of the crack tip, where the strain attenuation is greatest, and it is the current leading edge of the crack propagation. The three-dimensional crack propagation path data is a dataset that integrates the three-dimensional coordinate information of the crack initiation location, propagation angle, and tip location to reflect the crack development trajectory.

[0031] In some embodiments, the step of performing spatiotemporal feature analysis on the real-time strain data to obtain three-dimensional crack propagation path data including crack initiation location, propagation angle, and tip location includes: The real-time strain data is segmented according to the time series, and strain abrupt change points in each time period are extracted. The location of the strain abrupt change points is initially determined as the crack initiation location. A strain gradient field is constructed based on real-time strain data from different monitoring sections, and the crack propagation angle is determined by gradient direction analysis. Based on the attenuation pattern of the real-time strain data, the location of the maximum strain attenuation is determined to be the tip of the crack. The crack initiation location, the propagation angle, and the tip location are mapped in three dimensions to generate three-dimensional crack propagation path data.

[0032] First, the real-time strain data is segmented according to the time series. A suitable time interval is selected, for example, every 10 minutes, to divide the real-time strain data collected in step S1 into multiple consecutive time periods. For the data within each time period, the rate of change of strain is calculated. When the rate of change of strain exceeds a preset threshold (e.g., 5 microstrain / minute, determined based on the characteristics of concrete materials and extensive experimental data; when the rate of change of strain exceeds this value, it can be considered that cracks may appear inside the concrete), the three-dimensional coordinate location of the strain inflection point is preliminarily determined as the crack initiation location. For example, in a certain time period, if the strain change rate at x=3 m, y=0.25 m, z=0.4 m is 8 microstrain / minute, exceeding the threshold of 5 microstrain / minute, then this location is preliminarily determined as the crack initiation location.

[0033] Next, a strain gradient field is constructed based on real-time strain data from different monitoring sections. Using the finite element method (FEM), the real-time strain data collected from each monitoring section is imported into FEM software. The software calculates the strain gradient vectors at various points within the concrete, and these vectors constitute the strain gradient field. The direction of the strain gradient vector reflects the direction of the most drastic strain change, which is also the possible direction of crack propagation. By calculating the angle between this gradient direction and the preset monitoring section, the crack propagation angle is determined. For example, based on the constructed strain gradient field, if the angle between the gradient vector direction at a certain location and the longitudinal section is calculated to be 52.8 degrees, then this angle is determined as the crack propagation angle.

[0034] Then, the crack tip location is determined by combining the attenuation pattern of real-time strain data. Along the possible crack propagation direction (i.e., the gradient vector direction), the attenuation of real-time strain data is analyzed, and the attenuation rate of strain value with distance is calculated. The location with the largest strain attenuation rate, i.e., the place where the strain value decreases most rapidly with increasing distance, is determined as the crack tip location. Assuming that along the gradient direction, at a distance of 500 mm from the initiation location, the strain attenuation rate is -120 microstrain / m, which is the location with the largest attenuation rate in that direction, then this location (x=3.5 m, y=0.4 m, z=0.5 m) is located as the crack tip location.

[0035] Finally, the crack initiation location, propagation angle, and tip location are mapped using three-dimensional coordinates to generate three-dimensional crack propagation path data. The previously determined three-dimensional coordinate information of the crack initiation location, propagation angle, and tip location is uniformly mapped to the same three-dimensional coordinate system, organized and correlated according to time sequence and spatial positional relationships, forming trajectory data that can completely reflect the crack's trajectory from initiation to its current propagation state—that is, three-dimensional crack propagation path data.

[0036] In this embodiment, traditional crack monitoring methods can only roughly determine the location and direction of cracks by observing the concrete surface, failing to delve into the interior to obtain accurate three-dimensional information, leading to significant errors in crack propagation assessment. This step, however, through spatiotemporal feature analysis, combined with time series analysis and spatial gradient field construction, can accurately determine the crack initiation location, propagation angle, and tip location, and generate three-dimensional crack propagation path data. This provides a precise basis for the subsequent accurate deployment of the fiber-oriented distribution layer, effectively solving the problem that traditional methods cannot accurately obtain three-dimensional propagation information within cracks.

[0037] In this embodiment of the application, this step can accurately obtain the three-dimensional propagation path information of cracks inside concrete, overcome the shortcomings of traditional monitoring methods in terms of insufficient understanding of the internal conditions of cracks, and provide reliable data support for subsequent targeted crack blocking.

[0038] S3. Based on the three-dimensional crack propagation path data, identify the dominant development direction and potential propagation range of the crack, wherein the potential propagation range is a fan-shaped region extending along the propagation angle with the tip position as the vertex.

[0039] In the embodiments of this application, the dominant development direction is the trend direction that appears most frequently during the crack's expansion process, which can reflect the path that the crack is most likely to continue to extend; the potential expansion range is the area where the crack may expand in the future, which is fan-shaped and extends along the expansion angle with the tip of the crack as the vertex.

[0040] In some embodiments, identifying the dominant development direction and potential propagation range of the crack based on the three-dimensional crack propagation path data includes: Curve fitting is performed on the three-dimensional crack propagation path data to obtain the crack propagation trend curve; The dominant development direction and potential expansion range of the cracks are identified based on the trend curve.

[0041] In this embodiment of the application, curve fitting is a mathematical method used to fit the three-dimensional crack propagation path data into a continuous trend curve to more clearly reflect the overall trend of crack propagation. The trend curve is a curve obtained after fitting the three-dimensional crack propagation path data, which can intuitively show the development trajectory of the crack from its initiation to the current tip position and the possible future extension direction.

[0042] In some embodiments, identifying the dominant development direction and potential expansion range of cracks based on the trend curve includes: Calculate the tangent direction of the trend curve at each coordinate point, and determine the tangent direction with the highest frequency as the dominant development direction of the crack; The radius of the sector region is determined based on the stress distribution at the tip location, wherein the radius is positively correlated with the stress value at the tip location; The potential expansion range is a fan-shaped region extending along the expansion angle with the tip position as the vertex and having the radius.

[0043] In the embodiments of this application, the tangent direction is the instantaneous change direction of a certain point on the trend curve, which can reflect the specific direction of crack propagation at that point.

[0044] First, curve fitting is performed on the three-dimensional crack propagation path data. Using the least squares method, the coordinates of each point in the three-dimensional crack propagation path data obtained in step S2 (such as the initiation location, the tip position at different times, etc.) are substituted into a preset curve equation. For example, the spatial three-dimensional curve equations are x=a0+a1t, y=b0+b1t, and z=c0+c1t (where t is the time parameter, and a0, a1, b0, b1, c0, and c1 are coefficients to be determined). By calculating and determining the values ​​of the coefficients, a trend curve that best fits the original data points is obtained. Taking the previously determined crack initiation locations (3 meters, 0.25 meters, 0.4 meters) and tip positions (3.5 meters, 0.4 meters, 0.5 meters) as an example, the fitted trend curves are x=3+0.5t, y=0.25+0.3t, and z=0.4+0.2t.

[0045] Next, the dominant crack development direction is identified based on the trend curve. The tangent direction of the trend curve at each coordinate point is calculated. For the aforementioned trend curve, its tangent direction vector is (dx / dt, dy / dt, dz / dt), which is (0.5, 0.3, 0.2). The frequency of different tangent directions is statistically analyzed, and the tangent direction with the highest frequency is determined as the dominant crack development direction. In this example, the tangent direction vector (0.5, 0.3, 0.2) has the highest frequency of 60%, therefore this direction is determined as the dominant development direction.

[0046] Then, the radius of the fan-shaped region is determined based on the stress distribution at the tip. The stress value at the tip is calculated using the axial strain from the real-time strain data collected in step S1, combined with the elastic modulus of the concrete. The stress value equals the axial strain multiplied by the elastic modulus (the elastic modulus of concrete is taken as 30 GPa). For example, if the axial strain at the tip is 200 microstrains, then the stress value is 200 microstrains × 30 GPa = 6 MPa. The radius of the fan-shaped region is positively correlated with the stress value at the tip. The calculation formula is: radius = 0.02 m / MPa × stress value (0.02 m / MPa is an empirical coefficient derived from numerous concrete crack propagation tests). Substituting the stress value of 6 MPa, we get: radius = 0.02 m / MPa × 6 MPa = 0.12 m.

[0047] Finally, the potential propagation range was determined. Taking the tip position (3.5 m, 0.4 m, 0.5 m) as the vertex, the propagation angle of 52.8 degrees was extended along the previously determined propagation angle. Combined with the calculated radius of 0.12 m, and considering the possible deviation in crack propagation, the propagation angle was extended by 15 degrees to each side, forming an angle range of 37.8 degrees to 67.8 degrees. This fan-shaped area is the potential propagation range.

[0048] In this embodiment, traditional methods cannot accurately predict the dominant development direction and potential extension range of cracks, often only addressing the already existing cracks and failing to take preventative measures to stop further expansion. This step, however, precisely identifies the dominant development direction and potential extension range of cracks by performing curve fitting and trend analysis on three-dimensional crack propagation path data. This provides a clear spatial range and directional guidance for the subsequent deployment of the fiber orientation distribution layer, enabling fibers to be deployed in advance along the potential crack propagation path, effectively solving the problem of insufficient crack propagation prediction in traditional methods.

[0049] In the embodiments of this application, this step clarifies the main future propagation direction and possible extent of the crack.

[0050] S4. Within the potential expansion zone of the concrete pouring area, a fiber-oriented distribution layer arranged along the dominant development direction is formed by a fiber-oriented placement device.

[0051] In this embodiment, the concrete pouring area refers to the area where concrete has not yet been poured, where concrete pouring is planned, and where crack expansion may occur; the fiber orientation laying device is a device that can lay fibers in a specific direction according to preset parameters to form a fiber orientation distribution layer, including components such as a control system, nozzle, airflow conveying device, and magnetic field orientation device; the fiber orientation distribution layer is a fiber layer with a certain density and thickness formed by arranging fibers along the dominant development direction within the potential expansion range.

[0052] In some embodiments, forming a fiber-oriented distribution layer arranged along the dominant growth direction within the potential expansion range of the concrete pouring area using a fiber-oriented placement device includes: The parameters corresponding to the potential propagation range and the dominant development direction in the three-dimensional crack propagation path data are input into the control system of the fiber orientation deployment device; The control system arranges the fibers along the dominant growth direction according to the preset fiber density and layer thickness based on the parameters, and forms a fiber oriented distribution layer within the potential expansion range.

[0053] In some embodiments, the control system aligns the fibers along the dominant growth direction according to preset fiber density and layer thickness based on parameters, and forms a fiber-oriented distribution layer within the potential expansion range, including: The control system adjusts the nozzle angle and movement trajectory of the fiber orientation laying device according to parameters, so that the nozzle is aligned with the potential expansion range; The fiber orientation laying device delivers fibers to the nozzle by airflow traction, and at the nozzle, a magnetic field orientation device aligns the fibers along the dominant growth direction. According to the preset fiber density and layer thickness, a fiber-oriented distribution layer is formed within the potential expansion range.

[0054] In this embodiment, the control system is the core component of the fiber orientation laying device, used to receive parameters, process information, and control the operation of various parts of the device; the nozzle is a component in the fiber orientation laying device used to spray fibers, and its angle and movement trajectory can be adjusted by the control system; the airflow traction method is a conveying method that uses the force of airflow to transport fibers to the nozzle; the magnetic field orientation device is a device installed at the nozzle that generates a magnetic field to align the fibers along the dominant development direction.

[0055] In the embodiments of this application, fiber density refers to the number of fibers per unit area; layer thickness refers to the thickness of the fiber orientation distribution layer.

[0056] First, the parameters corresponding to the potential propagation range and dominant development direction in the three-dimensional crack propagation path data are input into the control system of the fiber orientation placement equipment. These parameters include the three-dimensional coordinate range of the potential propagation range (e.g., a sector area with a vertex of (3.5 m, 0.4 m, 0.5 m), a radius of 0.12 m, and an angle range of 37.8° to 67.8°) and the dominant development direction vector (0.5, 0.3, 0.2). After receiving these parameters, the control system analyzes and processes them to provide a basis for the subsequent operation of the control equipment.

[0057] Next, the control system adjusts the nozzle angle and movement trajectory of the fiber orientation deployment device according to the parameters, aligning the nozzle with the potential expansion zone. The control system calculates the required nozzle adjustment angle based on the dominant growth direction vector and drives the servo motor to adjust the nozzle angle to match the dominant growth direction (52.8°). Simultaneously, it plans the nozzle's movement trajectory based on the coordinate range of the potential expansion zone, ensuring that the nozzle covers the entire potential expansion zone. For example, the nozzle starts from the edge of the potential expansion zone (3.5m - 0.12m × sin52.8°, 0.4m - 0.12m × cos52.8°, 0.5m) and moves towards the center along the planned trajectory.

[0058] The fiber orientation equipment then transports the fibers to the nozzle via airflow. At the nozzle, a magnetic field orientation device aligns the fibers along the dominant growth direction. The airflow device generates airflow at a pressure of 0.4 MPa, drawing steel fibers 12 mm long and 0.2 mm in diameter from the storage device and transporting them to the nozzle. At the nozzle, the magnetic field orientation device generates a 0.2 T magnetic field. Under the influence of the magnetic force, the long axis of the steel fibers aligns along the dominant growth direction (52.8°), ensuring fiber orientation.

[0059] Finally, according to the preset fiber density and layer thickness, a fiber-oriented distribution layer is formed within the potential expansion range. The preset fiber density is 30 fibers / square millimeter, and the layer thickness is 10 millimeters. The control system controls the amount of fiber sprayed based on the nozzle's movement trajectory and the fiber conveying speed, ensuring that the number of fibers per unit area reaches 30 fibers / square millimeter. Simultaneously, by controlling the number of nozzle movements or the spraying time, the thickness of the fiber-oriented distribution layer reaches 10 millimeters, thereby forming a fiber-oriented distribution layer that meets the requirements within the potential expansion range.

[0060] In this embodiment, in traditional concrete crack resistance methods, fibers are often randomly distributed within the concrete, lacking specificity in blocking crack propagation and failing to effectively prevent cracks from extending in a particular direction. This step, however, utilizes a fiber-oriented placement device to precisely place fibers within the potential propagation zone and arrange them along the dominant growth direction. This allows the fibers to form an effective barrier along the potential crack propagation path, significantly improving the directional blocking effect on crack propagation and solving the problems of disordered fiber distribution and poor crack resistance targeting in traditional methods.

[0061] In the embodiments of this application, the technical effect of this step is that a fiber-oriented distribution layer arranged along its dominant growth direction is formed in the area where the crack may propagate, laying the foundation for effectively blocking the crack propagation and improving the crack resistance of the concrete.

[0062] S5. The concrete area to be poured, where the fiber-directed distribution layer is located, is compacted by vibration to form a fiber-reinforced concrete crack-resistant structure.

[0063] In this embodiment, vibration compaction is the process of using a vibrator to apply vibration to the concrete area to be poured in order to remove air bubbles in the concrete and make the concrete and the fiber-oriented distribution layer tightly bonded together; the fiber-reinforced concrete crack-resistant structure is an integral structure formed by the fiber-oriented distribution layer and the concrete matrix after vibration and solidification, which can use the oriented fibers to block the propagation of cracks.

[0064] In some embodiments, the step of vibrating and compacting the concrete area to be poured, where the fiber-oriented distribution layer is located, to form a fiber-reinforced crack-resistant concrete structure includes: Based on the location of the fiber-oriented distribution layer and the slump of the concrete, a vibrator is used to vibrate from the edge of the fiber-oriented distribution layer towards the center. After vibration, the concrete surface is smoothed, and after the concrete solidifies, a fiber-reinforced crack-resistant concrete structure is formed.

[0065] In the embodiments of this application, a vibrator is a device used to vibrate concrete to make it dense, and its vibration frequency and amplitude can be adjusted according to the characteristics of concrete; the slump of concrete is an indicator of the fluidity of concrete, and the larger the value, the better the fluidity of concrete; finishing is the operation of using tools such as trowels to repair the surface of concrete after the concrete has been vibrated, so as to make it smooth and flat.

[0066] The first step is to determine the vibration parameters. Based on the location of the fiber-oriented distribution layer in step S4 (e.g., z=0.5 meters) and the concrete slump (180±20 mm), a suitable immersion vibrator is selected, with a vibration frequency of 50 Hz and an amplitude of 0.8 mm. This parameter selection is based on extensive experimental verification, which shows that this frequency and amplitude effectively remove air bubbles within this slump range without disrupting the fiber orientation.

[0067] Next, the vibration operation is performed. The vibrator is inserted into the concrete 50 mm from the edge of the fiber-oriented layer, and then moved towards the center in 100 mm increments. Each vibration session is controlled to 12 seconds to ensure the concrete is fully compacted and the fibers are tightly bonded to the concrete matrix. For example, starting from the edge of the potential expansion zone (3.5 m - 0.12 m × sin52.8°, 0.4 m - 0.12 m × cos52.8°, 0.5 m), the vibration is gradually moved towards the center (3.5 m, 0.4 m, 0.5 m).

[0068] Then, the concrete surface is smoothed. After vibration, the concrete surface is smoothed with a trowel to ensure that the surface flatness does not exceed 5 mm, in order to guarantee the appearance and performance of the concrete structure.

[0069] Finally, wait for the concrete to set. The treated concrete undergoes 28 days of standard curing to allow it to reach the design strength, enabling the fiber-directed layer to form a strong, integrated structure with the concrete matrix, ultimately creating a fiber-reinforced, crack-resistant concrete structure.

[0070] In this embodiment, this step ensures a tight bond between the fiber-oriented distribution layer and the concrete matrix, enabling the fibers to fully exert their directional blocking effect, effectively preventing the disorderly propagation of cracks, and improving the crack resistance of the concrete structure.

[0071] like Figure 2 The diagram shown is a functional block diagram of a fiber-reinforced concrete crack-resistant system provided in an embodiment of the present invention.

[0072] The fiber-reinforced concrete crack-resistant system 100 described in this invention can be installed in an electronic device. Depending on the functions implemented, the fiber-reinforced concrete crack-resistant system 100 may include a real-time strain data acquisition module 101, a three-dimensional crack propagation path analysis module 102, a crack development direction and interval identification module 103, a fiber directional distribution layer layout module 104, and a fiber-reinforced concrete crack-resistant structure forming module 105. The module described in this invention can also be called a unit, referring to a series of computer program segments that can be executed by an electronic device processor and perform a fixed function, stored in the memory of the electronic device.

[0073] In this embodiment, the functions of each module / unit are as follows: The real-time strain data acquisition module 101 is used to acquire real-time strain data of concrete under stress and shrinkage by using distributed optical fiber sensors embedded in the concrete and arranged along a preset monitoring section. The three-dimensional crack propagation path analysis module 102 is used to perform spatiotemporal feature analysis on the real-time strain data to obtain three-dimensional crack propagation path data including crack initiation location, propagation angle and tip location. The crack development direction and interval identification module 103 is used to identify the dominant development direction and potential extension interval of the crack based on the three-dimensional crack extension path data, wherein the potential extension interval is a fan-shaped region extending along the extension angle with the tip position as the vertex. The fiber orientation distribution layer deployment module 104 is used to form a fiber orientation distribution layer arranged along the dominant development direction in the potential expansion range of the concrete to be poured area by means of a fiber orientation deployment device. The fiber-reinforced concrete crack-resistant structure forming module 105 is used to vibrate and compact the concrete area to be poured where the fiber-oriented distribution layer is located, thereby forming a fiber-reinforced concrete crack-resistant structure.

[0074] In the several embodiments provided by this invention, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0075] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0076] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0077] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0078] The embodiments of this application can acquire and process relevant data based on artificial intelligence technology. Artificial intelligence is the theory, method, technology, and application system that uses digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use that knowledge to obtain optimal results.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A fiber-reinforced concrete-based crack resistance method, characterized by, The method comprises: Collecting real-time strain data of the concrete under the action of stress and shrinkage through a distributed optical fiber sensor embedded in the interior of the concrete and arranged along a preset monitoring section; Analyzing the real-time strain data in terms of time and space to obtain three-dimensional crack propagation path data containing a crack initiation position, an expansion angle and a tip position; Identifying a dominant development direction and a potential expansion interval of the crack based on the three-dimensional crack propagation path data, wherein the potential expansion interval is a fan-shaped area with the tip position as a vertex and extending along the expansion angle; Forming a fiber directional distribution layer arranged along the dominant development direction in the potential expansion interval of the concrete pouring area through a fiber directional arrangement device; Performing a vibrating and compacting treatment on the concrete pouring area where the fiber directional distribution layer is located to form a fiber-reinforced concrete anti-cracking structure.

2. The fiber-reinforced concrete-based crack prevention method according to claim 1, wherein The preset monitoring section comprises longitudinal sections arranged at intervals along the length direction of the concrete structure, transverse sections along the width direction and vertical sections along the height direction.

3. The fiber-reinforced concrete-based crack prevention method according to claim 1, wherein The real-time strain data comprises axial strain, radial strain and shear strain, wherein the axial strain is determined based on the expansion performance index of the concrete structure in the length direction, the radial strain is determined based on the expansion attribute of the concrete structure in the width direction, and the shear strain is used to associate external data resources of the stress state of the concrete structure.

4. The fiber-reinforced concrete-based crack prevention method according to claim 1, wherein The analysis of the real-time strain data in terms of time and space to obtain the three-dimensional crack propagation path data containing the crack initiation position, the expansion angle and the tip position comprises: Segmenting the real-time strain data according to time sequences, extracting strain mutation points in each time period, and preliminarily determining the positions of the strain mutation points as the crack initiation positions; Constructing a strain gradient field based on the real-time strain data of different monitoring sections, and determining the expansion angle of the crack through gradient direction analysis; Positioning the tip position of the crack at the position of the maximum attenuation of the real-time strain data; Mapping the crack initiation position, the expansion angle and the tip position in three-dimensional coordinates to generate three-dimensional crack propagation path data.

5. The fiber-reinforced concrete-based crack prevention method according to claim 1, wherein The identification of the dominant development direction and the potential expansion interval of the crack based on the three-dimensional crack propagation path data comprises: Performing curve fitting on the three-dimensional crack propagation path data to obtain a trend curve of crack propagation; Identifying the dominant development direction and the potential expansion interval of the crack based on the trend curve.

6. The fiber-reinforced concrete-based crack prevention method according to claim 5, wherein The identification of the dominant development direction and the potential expansion interval of the crack based on the trend curve comprises: Calculating the tangent direction of the trend curve at each coordinate point, and determining the tangent direction with the highest occurrence frequency as the dominant development direction of the crack; Determining the radius of the fan-shaped area according to the stress distribution of the tip position, wherein the radius is positively correlated with the stress value of the tip position; Taking the tip position as a vertex, extending along the expansion angle and having the radius, the fan-shaped area is the potential expansion interval.

7. The fiber-reinforced concrete-based crack prevention method according to claim 1, wherein The forming of the fiber directional distribution layer arranged along the dominant development direction in the potential expansion interval of the concrete pouring area through the fiber directional arrangement device comprises: Inputting parameters corresponding to the potential extension interval and the dominant development direction in the three-dimensional crack propagation path data into a control system of a fiber orientation laying device; The control system arranges fibers along the dominant development direction according to parameters, and lays fibers in the potential extension interval to form a fiber orientation distribution layer according to preset fiber density and layer thickness.

8. The fiber-reinforced concrete-based crack prevention method according to claim 7, wherein The control system arranges fibers along the dominant development direction according to parameters, and lays fibers in the potential extension interval to form a fiber orientation distribution layer according to preset fiber density and layer thickness, including: The control system adjusts the angle and moving track of the nozzle of the fiber orientation laying device according to parameters, so that the nozzle is aligned with the potential extension interval; The fiber orientation laying device transports fibers to the nozzle by airflow traction, and arranges fibers along the dominant development direction by a magnetic field orientation device at the nozzle; According to preset fiber density and layer thickness, fibers are laid in the potential extension interval to form a fiber orientation distribution layer.

9. The fiber-reinforced concrete crack resistance method according to any one of claims 1 to 8, wherein The fiber orientation distribution layer is in the concrete pouring area, and the fiber reinforced concrete crack-resistant structure is formed by vibrating and compacting the concrete pouring area, including: According to the position of the fiber orientation distribution layer and the slump of the concrete, a vibrator is used to vibrate from the edge to the center of the fiber orientation distribution layer, and after the vibration is completed, the surface of the concrete is treated by troweling, and the fiber reinforced concrete crack-resistant structure is formed after the concrete solidifies.

10. A fiber-reinforced concrete crack resistance system, characterized by, The system includes: A real-time strain data acquisition module for acquiring real-time strain data of concrete under stress and shrinkage by a distributed optical fiber sensor embedded in the concrete and arranged along a preset monitoring section; A three-dimensional crack propagation path analysis module for analyzing the real-time strain data in space and time to obtain three-dimensional crack propagation path data including crack initiation position, propagation angle and tip position; A crack development direction and interval identification module for identifying the dominant development direction and potential extension interval of the crack based on the three-dimensional crack propagation path data, wherein the potential extension interval is a fan-shaped area with the tip position as the vertex and extending along the propagation angle; A fiber orientation distribution layer laying module for forming a fiber orientation distribution layer arranged along the dominant development direction in the potential extension interval of the concrete pouring area by a fiber orientation laying device; A fiber reinforced concrete crack-resistant structure forming module for vibrating and compacting the concrete pouring area where the fiber orientation distribution layer is located to form a fiber reinforced concrete crack-resistant structure.

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