Modified expanded vermiculite cement mortar performance detection system and method

Abstract

The invention relates to the technical field of building material performance detection, and particularly discloses a modified expanded vermiculite cement mortar performance detection system and a modified expanded vermiculite cement mortar performance detection method. The method comprises the following steps: acquiring torque and sound wave signals in a mortar hydration hardening process in real time, identifying a sudden change event point of synchronous sudden increase of mechanical and acoustic signals, extracting critical network formation characteristic parameters, namely critical time, the jump amplitude of the torque signal and the gain amplitude of the acoustic signal, and comparing with a standard database to generate a performance evaluation report. According to the method, the hysteresis of a traditional destructive test is broken through, whole-course dynamic monitoring from a flow state to a solid state is realized, key nodes formed by a microstructure are accurately positioned, high-resolution data support is provided for material performance optimization and quality control, and the method has engineering application values of shortening the research and development period, predicting long-term performance and the like.

Description

Technical Field

[0001] This invention belongs to the field of building material performance testing technology, and relates to a modified expanded vermiculite cement mortar performance testing system and method. Background Technology

[0002] Currently, the research and application of high-performance and functionalized cement mortars are becoming increasingly widespread, especially mortars incorporating lightweight functional fillers such as modified expanded vermiculite to improve their thermal insulation or crack resistance. However, how to accurately and rapidly evaluate the formation process of these additives in the microstructure of mortar and their true contribution to early performance has become a major challenge in the field of materials science and engineering. Existing detection methods struggle to capture the key microstructure evolution events dominated by specific additives during the transition of mortar from a fluid to a solid state, thus limiting the in-depth understanding and rapid optimization of mortar performance.

[0003] The industry's commonly used methods for testing mortar performance primarily rely on standardized physical tests. For example, the initial workability of premixed mortar is tested using a slump cone or rheometer, followed by the fabrication of standard-sized specimens and destructive testing of mechanical properties such as compressive and flexural strength at specific ages. For microstructure, offline, static observation is typically performed using techniques such as scanning electron microscopy. These methods form the basic framework for current quality control and materials research, providing macroscopic indicators of the final mortar performance.

[0004] However, these traditional methods have significant drawbacks. Destructive testing is inherently lagging, providing only performance data at discrete time points and failing to continuously track the complete dynamic process of early strength development in mortar, resulting in long R&D cycles and slow feedback. Simultaneously, macroscopic mechanical testing cannot clearly distinguish between the improvement in overall material performance and the skeletal network effect formed by specific components at the microscopic level, making it difficult to reveal their mechanism of action. Offline microscopic observation disrupts the original water content and structure of the sample, has a limited observation range, lacks real-time capability, and cannot capture the dynamic locking moment of the structure from non-existence to existence and from weak to strong. Summary of the Invention

[0005] In view of this, in order to solve the problems mentioned in the background art, a modified expanded vermiculite cement mortar performance testing system and method are proposed.

[0006] The objective of this invention can be achieved through the following technical solution: The first aspect of this invention provides a modified expanded vermiculite cement mortar performance testing system, comprising: a sensing probe preparation module, for preparing a force-acoustic coupling sensing probe, the force-acoustic coupling sensing probe integrating an ultrasonic transceiver module and having a non-smooth micron-scale array structure matching the average particle size of the modified expanded vermiculite particles.

[0007] The initial state reference signal acquisition module immerses the force-acoustic coupling sensing probe into the modified expanded vermiculite cement mortar that has just been stirred and is in a fluid state. The initial state reference signal is acquired by driving the force-acoustic coupling sensing probe to rotate at a low speed and activating the ultrasonic transceiver module. The low speed is defined as a rotation speed that is sufficient to sense rheological properties but insufficient to produce a centrifugal separation effect.

[0008] The real-time dynamic signal sequence acquisition module, starting from the initial state reference signal, continuously drives the force-acoustic coupling induction probe to rotate at low speed and transmit and receive sound waves during the hydration and hardening process of cement mortar, acquiring a real-time dynamic signal sequence that includes the evolution of mechanical response and acoustic characteristics.

[0009] The synchronous mutation event point identification module identifies synchronous mutation event points in a real-time dynamic signal sequence by monitoring the rate of change of mechanical response and acoustic characteristics. The synchronous mutation event points where a sudden increase in mechanical signal and a sudden increase in acoustic signal occur simultaneously refer to a step change in both mechanical and acoustic signals.

[0010] The feature parameter extraction module extracts feature parameters from the critical network based on the position and signal changes of synchronous mutation event points in the real-time dynamic signal sequence.

[0011] The evaluation report generation module compares the critical network formation characteristic parameters with a preset mortar standard performance database to generate a mortar performance evolution evaluation report. The mortar standard performance database pre-stores the correlation between the critical network formation characteristic parameters of multiple sets of benchmark mortars and their corresponding known macroscopic performance indicators.

[0012] The second aspect of the present invention provides a method for testing the performance of modified expanded vermiculite cement mortar, comprising: S1, preparing a force-acoustic coupling induction probe, wherein the force-acoustic coupling induction probe integrates an ultrasonic transceiver module and has a non-smooth micron-scale array structure that matches the average particle size of the modified expanded vermiculite particles.

[0013] S2. Immerse the force-acoustic coupling sensing probe into the modified expanded vermiculite cement mortar that has just been stirred and is in a fluid state. Drive the force-acoustic coupling sensing probe at a low speed and activate the ultrasonic transceiver module to obtain the initial state reference signal. The low speed is defined as a rotation speed that is sufficient to sense rheological properties but insufficient to produce a centrifugal separation effect.

[0014] S3. Starting from the initial state reference signal, during the hydration and hardening process of cement mortar, the force-acoustic coupling induction probe is continuously driven to rotate at low speed and transmit and receive sound waves, collecting real-time dynamic signal sequences that include the evolution of mechanical response and acoustic characteristics.

[0015] S4. In a real-time dynamic signal sequence, by monitoring the rate of change of mechanical response and acoustic characteristics, identify the synchronous abrupt change event point where a sharp increase in mechanical signal and a sharp increase in acoustic signal occur simultaneously. The sharp increase in mechanical signal and the sharp increase in acoustic signal refer to both mechanical signal and acoustic signal undergoing a step change.

[0016] S5. Based on the position and signal changes of synchronous mutation event points in the real-time dynamic signal sequence, extract the critical network to form feature parameters.

[0017] S6. Compare the critical network formation characteristic parameters with the preset mortar standard performance database to generate a mortar performance evolution evaluation report. The mortar standard performance database pre-stores the correlation between the critical network formation characteristic parameters of multiple sets of benchmark mortars and their corresponding known macroscopic performance indicators.

[0018] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: (1) The present invention realizes real-time continuous monitoring of the entire process of cement mortar transitioning from a fluid state to a solid state through synchronous coupling detection of mechanical and acoustic signals. Compared with traditional methods that can only perform discrete destructive tests at specific ages, this method can capture the complete performance evolution curve, including initial fluidity, setting process and early strength development. In particular, it can accurately identify the key time nodes for the formation of internal microstructures, providing high-resolution data for understanding the dynamic development law of material properties and greatly shortening the evaluation cycle.

[0019] (2) By identifying steep abrupt changes in torque and acoustic signals simultaneously, this invention can pinpoint the physical moment of formation of the modified expanded vermiculite microstructure network. This synchronous verification of mechanical response and microstructure changes effectively eliminates the possibility of misjudgment caused by noise or other interference factors in a single signal, thereby enabling a more accurate characterization of the occurrence of key phase transitions within the mortar and providing a more solid physical basis for performance evaluation.

[0020] (3) This invention can specifically quantify the contribution of specific functional additives, providing a basis for material design. The micron-scale array structure design on the probe surface makes it particularly sensitive to the network overlap and locking behavior of modified expanded vermiculite particles. By analyzing the occurrence time of synchronous mutation events, torque jump amplitude and acoustic gain, the formation efficiency, initial strength contribution and network structure uniformity of vermiculite skeleton can be directly evaluated, thereby directly linking macroscopic performance with the microscopic effects of specific components, breaking through the limitation of traditional methods that cannot distinguish the contributions of different components.

[0021] (4) By comparing the extracted critical network formation characteristic parameters with a standard performance database, this invention can quickly determine the early strength development rate and microstructure uniformity of mortar, and further predict its long-term performance indicators such as crack resistance potential. This predictive ability based on early dynamic characteristics enables scientific prediction of the final performance of materials at the initial stage of material research and development or on-site construction, realizing the pre-emptive quality control and having important engineering application value. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the system structure connection of the present invention.

[0024] Figure 2 This is a schematic diagram of the method steps of the present invention. Detailed Implementation

[0025] 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.

[0026] Please see Figure 1 The first aspect of the present invention provides a modified expanded vermiculite cement mortar performance testing system, comprising: a sensing probe preparation module, an initial state reference signal acquisition module, a real-time dynamic signal sequence acquisition module, a synchronous mutation event point identification module, a feature parameter extraction module, and an evaluation report generation module.

[0027] The sensing probe preparation module is connected to the initial state reference signal acquisition module. Both the sensing probe preparation module and the initial state reference signal acquisition module are connected to the real-time dynamic signal sequence acquisition module. The real-time dynamic signal sequence acquisition module is connected to the synchronous mutation event point identification module. Both the real-time dynamic signal sequence acquisition module and the synchronous mutation event point identification module are connected to the feature parameter extraction module. The feature parameter extraction module is connected to the evaluation report generation module.

[0028] The sensing probe preparation module prepares a force-acoustic coupled sensing probe, which integrates an ultrasonic transceiver module and has a non-smooth micron-scale array structure that matches the average particle size of the modified expanded vermiculite particles.

[0029] In a specific embodiment of the present invention, the specific steps for preparing the force-acoustic coupling sensing probe include: obtaining the average particle size of the modified expanded vermiculite particles.

[0030] The probe body is made of a metal material with high strength and acoustic conductivity.

[0031] On the surface of the probe body, a non-smooth micron-scale array structure is formed based on the average particle size of the modified expanded vermiculite particles. This enables the modified expanded vermiculite particles to wedge and lock with the non-smooth micron-scale array structure, thereby transforming the formation of the micro-locking state into changes in mechanical and acoustic signals that can be sensed by the force-acoustic coupling sensing probe.

[0032] An ultrasonic transceiver module is integrated into the non-contact end of the probe body to prepare a force-acoustic coupling sensing probe.

[0033] It should be noted that the process of fabricating a force-acoustic coupling induction probe begins with the selection of the base material. The first step is to select a metal material with high strength and acoustic conductivity, such as TC4 titanium alloy or 316L stainless steel. These materials ensure that the probe maintains its structural integrity in the highly abrasive environment of cement mortar while effectively transmitting sound waves. Then, the selected metal material is machined into the probe body using a precision lathe or CNC milling machine. The shape of the probe body is set as either cylindrical or paddle-shaped. The cylindrical design helps to reduce disturbance to the mortar flow field, while the paddle-shaped design increases the contact area with the mortar and enhances the sensitivity of the torque signal. The size of the probe body needs to be determined according to the specifications of the mortar container to ensure that it can be completely immersed in the mortar and does not collide with the container wall during rotation. After completing the basic machining of the probe body, the surface treatment stage begins. The second step is to form a non-smooth micron-scale array structure on the surface of the probe body through etching or micro-machining processes. The specific operation involves first performing particle size analysis on the modified expanded vermiculite particles to be tested to obtain their average particle size, and then designing the specific dimensions of the array structure based on this particle size data. For example, if the average particle size of the vermiculite is 50 micrometers, the feature size of the grooves or protrusions in the array structure can be set between 20 and 30 micrometers, with a depth of 10 to 15 micrometers. The purpose of this design is to allow the smaller vermiculite particles to wedge into the non-smooth micrometer-scale array structure when the probe rotates during subsequent testing, thereby forming an effective mechanical lock, and reflecting the change in this microscopic locking state through torque and acoustic signals. This structure can be achieved using laser etching technology, where a high-energy laser beam precisely etches the preset array pattern on the surface of the probe body. The third step is to integrate an ultrasonic transceiver module at the non-contact end of the probe body and connect the entire module to a drive device. This ultrasonic transceiver module is a device that converts electrical signals into high-frequency sound waves and receives sound waves back into electrical signals. It is securely mounted on the end of the probe that does not contact the mortar, ensuring that the sound waves can effectively propagate along the probe body to the part immersed in the mortar. Subsequently, the probe body integrating the ultrasonic transceiver module is mechanically and electrically connected to the drive device. The drive device itself is a precision motor system capable of applying minute rotations and synchronously recording torque, such as a stepper motor or servo motor with a high-precision torque sensor. Through this integrated assembly, a force-acoustic coupled sensing probe that integrates mechanical sensing and acoustic detection functions is finally fabricated.

[0034] Among them, metallic materials with high strength and acoustic conductivity refer to metals with a Young's modulus greater than 100 gigapascals and an acoustic impedance between 40 and 50 megarayles, such as TC4 titanium alloy. Its high strength ensures that the probe does not deform when rotating in viscous slurry, while its good acoustic properties guarantee that the sound wave signal can propagate within the probe with low loss. The probe body is the core load-bearing and sound-transmitting component of the force-acoustic coupling induction probe. Its data structure is a three-dimensional solid with a specific geometric shape, functioning as a sensor of mechanical torque and a medium for sound wave propagation. The non-smooth micron-scale array structure is an ordered arrangement of a series of micro-grooves or protrusions machined on the surface of the probe body. Its characteristic attribute is that the geometric dimensions of the array units match the average particle size of the modified expanded vermiculite particles to be tested. This setting is based on achieving effective wedging of the vermiculite particles, typically set to 0.4 to 0.6 times the average particle size. This ratio is obtained based on several experiments on the wedging efficiency of vermiculite with different particle sizes and different array sizes. Modified expanded vermiculite particles are a lightweight functional aggregate in cement mortar. Surface modification enhances their bonding with the cement matrix, and their average particle size is a key input parameter for designing non-smooth micron-scale array structures. The ultrasonic transceiver module is an integrated electronic component that transmits ultrasonic pulses and receives echo signals. Its data structure is a package containing a piezoelectric transducer, signal generation circuit, and signal receiving amplification circuit. Its operating frequency is typically set at 1 MHz to ensure both penetration and high sensitivity to microstructural changes. The drive unit is an electromechanical system that provides controllable low-speed rotational power to the force-acoustic coupling sensing probe and measures the resistance torque experienced by the probe in real time. Its data structure includes a motor, a reducer, a torque sensor, and a controller. The force-acoustic coupling sensing probe, the final product of this step, is a composite sensor that simultaneously acquires the mechanical response and acoustic characteristics of the cement mortar during the hardening process.

[0035] For example, a force-acoustic coupling sensing probe for detecting cement mortar containing modified expanded vermiculite particles with an average particle size of 45 micrometers is prepared. First, a TC4 titanium alloy rod with a diameter of 10 mm and a length of 150 mm is selected as the metal material, possessing high strength and acoustic conductivity, and is processed into a columnar probe body. Next, a non-smooth micron-scale array structure is formed on the surface of the 100 mm long immersion section of the probe body using femtosecond laser micromachining technology. The microgrooves of this structure are set to a width of 20 micrometers and a depth of 10 micrometers, dimensions matching the average particle size of the 45-micrometer modified expanded vermiculite particles. Subsequently, an ultrasonic transceiver module with a center frequency of 1 MHz is integrated into the top of the non-contact end of the probe body. Finally, the probe body with the assembled module is connected via a coupling to a dynamic torque sensor with a maximum range of 10 N·m. This sensor is in turn connected to a stepper motor providing a constant speed of 5 revolutions per minute; this motor system serves as the drive device. After completing the above steps, you will obtain a force-acoustic coupling induction probe that can be used for subsequent detection.

[0036] The initial state reference signal acquisition module immerses the force-acoustic coupling sensing probe into the modified expanded vermiculite cement mortar that has just been stirred and is in a fluid state. By driving the force-acoustic coupling sensing probe to rotate at a low speed and activating the ultrasonic transceiver module, the initial state reference signal is acquired. The low speed is defined as a rotational speed that is sufficient to sense rheological properties but insufficient to produce a centrifugal separation effect.

[0037] In a specific embodiment of the present invention, the specific steps of obtaining the initial state reference signal by driving the force-acoustic coupling sensing probe to rotate at a low speed and activating the ultrasonic transceiver module include: receiving a driving command to make the force-acoustic coupling sensing probe rotate at a constant low speed in the modified expanded vermiculite cement mortar.

[0038] The initial torque value experienced by the force-acoustic coupling sensing probe during rotation and the initial sound wave attenuation value received are recorded simultaneously.

[0039] The initial torque value and the initial acoustic attenuation value are combined to generate the initial state reference signal.

[0040] It should be noted that the process of obtaining the initial state reference signal begins with the preparation of the sample to be tested. First, the force-acoustic coupling induction probe prepared in the previous step is mounted and fixed on the chuck of the drive device. At the same time, cement, sand, water, and modified expanded vermiculite are weighed according to a predetermined ratio and placed in a mixer for mixing until a uniform, lump-free, and still fluid modified expanded vermiculite cement mortar is formed. Then, the force-acoustic coupling induction probe is vertically and slowly immersed into the center of the container containing this mortar. The immersion depth must ensure that the non-smooth micron-scale array structure area processed on the probe body is completely covered by the mortar. Next, the control program of the drive device is started, and a constant low-speed rotation command is set and executed, so that the force-acoustic coupling induction probe rotates in the mortar at a preset stable speed. As the probe begins to rotate, the ultrasonic transceiver module integrated on the tip of the probe is activated by the control system, so that it emits ultrasonic waves at a set pulse repetition frequency. The sound waves propagate along the probe body and interact with the surrounding mortar. The module then receives the returned sound wave feedback. The final step is data synchronization and recording. Within a short time window after the probe stabilizes and rotates, the control system synchronously reads and records the initial torque value from the torque sensor of the drive unit and the initial acoustic attenuation value automatically calculated by the signal processing unit of the ultrasonic transceiver module. These two stable measured values ​​are paired to form a two-dimensional data point. This data point is defined as the initial state reference signal characterizing the initial fluidity and acoustic properties of the mortar, serving as the zero-point reference for subsequent monitoring processes.

[0041] The target material for this test was the freshly mixed, fluid-state modified expanded vermiculite cement mortar. Its characteristic property is its initial state before significant hydration, exhibiting a viscous fluid nature, with vermiculite particles and aggregates uniformly suspended within the cement paste. Low-speed rotation refers to a constant rotational speed used to sense rheological properties without significantly disturbing the internal structural stability of the mortar. This speed is set to ensure measurable torque signals while avoiding centrifugal separation or turbulence effects. Based on several tests of fluids with different viscosities, the rotational speed is typically set between 1 and 10 revolutions per minute. Acoustic feedback is the echo signal received by the ultrasonic transceiver module after the acoustic pulse emitted by the transceiver module is reflected and scattered at the probe-mortar interface. Its characteristic property is that the amplitude and phase of the signal change due to the density, viscosity, and other physical properties of the mortar. The initial torque value is the initial measured value of the torque required to overcome the viscous resistance of the mortar when the force-acoustic coupled induction probe rotates at low speed in the fluid-state mortar. It directly reflects the initial flow properties of the mortar and is a mechanical scalar quantity. The initial acoustic attenuation value is the reduction in the intensity of the acoustic feedback signal relative to the transmitted signal intensity, usually expressed in dB. It reflects the degree of energy loss during acoustic propagation in the mortar medium and is a key parameter characterizing the initial acoustic properties of the mortar. The initial state reference signal is a data pair consisting of the initial torque value and the initial acoustic attenuation value. Its data structure is a two-dimensional vector, and its function is to provide a clear starting reference point for signal changes during the subsequent hardening process of cement mortar.

[0042] For example, the force-acoustic coupling sensing probe prepared in the previous step is immersed in a freshly stirred, fluid-state modified expanded vermiculite cement mortar. The drive device is activated, causing the force-acoustic coupling sensing probe to rotate at a constant low speed of 5 revolutions per minute, while the ultrasonic transceiver module is activated. The data acquisition system begins recording 10 seconds after the probe has stabilized, measuring the initial torque value at this point as 0.8 N·m. Simultaneously, the ultrasonic signal processing unit calculates the initial sound wave attenuation value as 15 dB. The system records this pair of values ​​(0.8 N·m, 15 dB) to generate an initial state reference signal for subsequent comparative analysis.

[0043] The real-time dynamic signal sequence acquisition module, starting from the initial state reference signal, continuously drives the force-acoustic coupling induction probe to rotate at low speed and transmit and receive sound waves during the hydration and hardening process of cement mortar, and acquires a real-time dynamic signal sequence that includes the evolution of mechanical response and acoustic characteristics.

[0044] In a specific embodiment of the present invention, the specific steps of acquiring a real-time dynamic signal sequence including the evolution of mechanical response and acoustic characteristics include: continuously and synchronously acquiring the torque value and acoustic feedback parameters of the force-acoustic coupling induction probe rotation at a preset sampling frequency.

[0045] A common timestamp is added to the torque value and acoustic feedback parameters of each group of synchronously acquired force-acoustic coupling induction probes to form torque data sequences and acoustic data sequences.

[0046] The torque data sequence and the acoustic wave data sequence are aligned according to the timestamps to form a real-time dynamic signal sequence.

[0047] It should be noted that the acquisition of real-time dynamic signal sequences is a continuous monitoring process seamlessly connected after obtaining the initial state reference signal. Using the initial state reference signal, which records the initial torque value and the initial acoustic attenuation value, as the zero point of time, the detection system runs continuously. The drive device precisely maintains the force-acoustic coupling sensing probe at a previously set constant low speed of rotation, while the ultrasonic transceiver module continues to transmit and receive sound waves at a predetermined frequency. During this process, the cement mortar undergoes a chemical reaction between the internal cement particles and water, entering the hydration and hardening process. Its physical state gradually changes from fluid to semi-solid and even solid, with increased viscosity and internal structural complexity. To capture this change, the control system performs uninterrupted synchronous acquisition. Specifically, the system acquires data at a preset sampling frequency, such as once per minute. At each sampling moment, it synchronously reads the torque value experienced by the force-acoustic coupling sensing probe from the torque sensor and obtains acoustic feedback parameters from the ultrasonic signal processing unit. To ensure data synchronization, each acquired torque value and acoustic parameter is assigned a common, second-accurate timestamp by the system. In this way, over time, the system generates two parallel data streams: one for torque data and the other for acoustic data. These two streams are strictly one-to-one corresponded through timestamps. Finally, the system integrates these continuously acquired, timestamp-aligned torque and acoustic data into a structured dataset. This dataset constitutes a real-time dynamic signal sequence containing the evolution of mechanical response and acoustic properties, providing a complete raw data foundation for subsequent analysis steps.

[0048] The torque value experienced by the force-acoustic coupling induction probe during rotation is a real-time measurement of the torque required to maintain constant probe rotation at any moment during the hydration and hardening process. Its variation reflects the increase in the shear resistance within the mortar. Acoustic feedback parameters are real-time values ​​quantifying the characteristics of the acoustic feedback signal, such as the peak voltage or signal energy of the echo signal. Their variations reflect the evolution of the microstructure density or solid-phase network connectivity within the mortar. Torque data consists of a series of probe rotation torque values ​​arranged in chronological order, with a data structure of a one-dimensional time-series array. Acoustic data consists of a series of acoustic feedback parameters arranged in chronological order, also with a data structure of a one-dimensional time-series array.

[0049] The synchronous mutation event point identification module identifies synchronous mutation event points where a sudden increase in mechanical signal and a sudden increase in acoustic signal occur simultaneously in a real-time dynamic signal sequence by monitoring the rate of change of mechanical response and acoustic characteristics. The sudden increase in mechanical signal and the sudden increase in acoustic signal refer to a step change in both mechanical signal and acoustic signal.

[0050] In a specific embodiment of the present invention, the specific steps for identifying the synchronous abrupt change event point where a sharp increase in mechanical signal and a sharp increase in acoustic signal occur simultaneously include: calculating the rate of change of torque value and the rate of change of acoustic feedback parameters in a real-time dynamic signal sequence.

[0051] It should be noted that the process of identifying synchronous abrupt change event points involves analyzing and processing the real-time dynamic signal sequence acquired in the previous step. First, the system loads a real-time dynamic signal sequence containing timestamps, the torque value experienced by the force-acoustic coupling sensing probe during rotation, and acoustic feedback parameters. Next, the system monitors the torque and acoustic data in this real-time dynamic signal sequence in real time, focusing on calculating their rates of change. For each consecutive data point in the real-time dynamic signal sequence, the system calculates the rate of change of the torque value and the rate of change of the acoustic feedback parameters. This calculation is performed by subtracting the value of the previous data point from the value of the current data point and then dividing by the time interval between the two data points.

[0052] It should also be noted that the specific formulas for calculating the rate of change of torque and the rate of change of acoustic feedback parameters are as follows: , , in the formula, Representative at The rate of change of the torque value at any given time. and They are at the current moment and the previous moment The torque value collected during the rotation of the force-acoustic coupling induction probe. Representative at The rate of change of the acoustic feedback parameters at any given time. and They are at the current moment and the previous moment Acquired acoustic feedback parameters. and These are two consecutive sampling timestamps.

[0053] The rate of change of torque value is compared with a preset mechanical threshold to identify sharp increases in the mechanical signal.

[0054] The rate of change of the acoustic feedback parameters is compared with a preset acoustic threshold to identify a sharp increase in the acoustic signal.

[0055] Match the timing of the sudden increase in mechanical signal with the timing of the sudden increase in acoustic signal, and mark the moment when the sudden increase in mechanical signal and the sudden increase in acoustic signal occur simultaneously as the synchronous mutation event point.

[0056] It should be noted that when the system detects that the rate of change of the torque value at a certain moment exceeds a preset mechanical threshold, it determines that a sharp increase in the mechanical signal has occurred. Simultaneously, if the rate of change of the acoustic feedback parameter at that moment exceeds a preset acoustic threshold, it determines that a sharp increase in the acoustic signal has occurred. The system then performs a time-based matching of these two events. Finally, when the system confirms that at a specific moment, both the mechanical and acoustic signal sharp increases are simultaneously satisfied, the system marks this precise timestamp, defining it as the synchronous abrupt change event point characterizing the locking of the vermiculite micro-skeleton network. Physically, the occurrence of this point corresponds to the instant when the cement mortar transitions from a discrete particle suspension state to a preliminary solid-phase network structure formed by the overlapping and wedging of modified expanded vermiculite particles.

[0057] In one specific embodiment of the present invention, the preset mechanical threshold is typically set to 2.0 N·m / min, based on industry research on the critical torque change rate of microstructure formation during the early hydration process of cement-based materials. Related literature indicates that when modified expanded vermiculite particles form an initial skeleton network in mortar, the torque required for probe rotation increases sharply due to the interparticle overlap and locking effect. The threshold of 2.0 N·m / min can eliminate the interference of ordinary viscous resistance changes in fluid mortar, accurately capturing the mechanical characteristics of microstructure formation. The acoustic threshold is typically set to -3.0 dB / min, based on research on the propagation characteristics of ultrasound in the microstructure evolution of cement-based materials. When a solid-phase network forms inside the mortar, the sound wave attenuation rate decreases significantly due to the increase in medium density. The threshold of -3.0 dB / min integrates industry experimental conclusions on the correlation between acoustic signals and microstructure density, effectively distinguishing the acoustic differences between ordinary moisture evaporation and key skeleton network locking.

[0058] For example, assume the system records data at the 95th minute (95 min, 4.5 N·m, 6 dB) and at the 96th minute (96 min, 8.0 N·m, 2 dB). The system calculates the rate of change of torque at the 96th minute: (8.0 - 4.5) / (96 - 95) = 3.5 N·m / min. Simultaneously, it calculates the rate of change of acoustic attenuation: (2 - 6) / (96 - 95) = -4.0 dB / min. Assume the preset threshold for a sharp increase in mechanical signal is a rate of change of torque greater than 2.0 N·m / min, and the threshold for a sharp increase in acoustic signal is a rate of change of acoustic attenuation less than -3.0 dB / min. Since 3.5 is greater than 2.0 and -4.0 is less than -3.0, both conditions are simultaneously met at the specific moment of the 96th minute. Therefore, the system marks the 96th minute as the synchronous abrupt change event point characterizing the locking of the vermiculite microstructure network.

[0059] The feature parameter extraction module extracts feature parameters from the critical network based on the position and signal changes of synchronous mutation event points in the real-time dynamic signal sequence.

[0060] In a specific embodiment of the present invention, the specific steps for extracting the critical network formation feature parameters include: calculating the time from the start of detection to the occurrence of the synchronous mutation event point to obtain the critical time.

[0061] It should be noted that the process of extracting the characteristic parameters of the critical network formation is based on the quantitative analysis of the synchronous mutation event points identified in the previous step. First, the system locates the timestamp of the synchronous mutation event point. The system reads the value of this timestamp and calculates the total time elapsed from the start of detection to this timestamp; this time is defined as the critical time.

[0062] The amplitude of the torque signal jump in the real-time dynamic signal sequence before and after the synchronous mutation event point is quantified.

[0063] Quantize the gain amplitude of the acoustic signal in the real-time dynamic signal sequence before and after the synchronous mutation event point.

[0064] In a specific embodiment of the present invention, the amplitude of the torque signal is obtained by calculating the difference between the average torque value of the stable phase after the synchronous mutation event point and the average torque value of the stable phase before the synchronous mutation event point; the gain amplitude of the acoustic signal is obtained by calculating the difference between the average acoustic parameter value of the stable phase before the synchronous mutation event point and the average acoustic parameter value of the stable phase after the synchronous mutation event point.

[0065] It should be noted that, next, the system needs to extract the amplitude of changes in torque and acoustic signals around this synchronous abrupt change event point in the real-time dynamic signal sequence. To this end, the system selects data points from the stable phase before the synchronous abrupt change event point as the baseline value before the jump, and data points from the new stable phase after the jump as the peak value after the jump. Specifically, within a short time window before the synchronous abrupt change event point, the average value of the torque signal is calculated as the torque baseline before the jump; within a short time window after the synchronous abrupt change event point, the average value of the torque signal is calculated as the peak torque value after the jump. Then, the peak torque value after the jump is subtracted from the torque baseline before the jump to obtain the jump amplitude of the torque signal. Using the exact same method, the system processes the acoustic signal to calculate the acoustic signal baseline and peak value before and after the jump; the difference between the two is the gain amplitude of the acoustic signal.

[0066] The critical time, the rise amplitude of the torque signal, and the gain amplitude of the acoustic signal are combined to generate a critical network that forms characteristic parameters.

[0067] It should be noted that, finally, the three independent values ​​of critical time, torque signal rise amplitude, and acoustic signal gain amplitude are combined to form a three-dimensional vector. This vector is defined as the critical network formation characteristic parameter and is used for subsequent comprehensive evaluation of mortar performance.

[0068] The critical time is the time elapsed from the start of detection to the occurrence of the synchronous mutation event, directly reflecting the speed at which modified expanded vermiculite forms the initial skeleton network in cement mortar. The torque signal surge amplitude is the net increase in probe rotation torque before and after the synchronous mutation event, quantifying the initial strength or shear resistance of the formed vermiculite micro-skeleton network. The acoustic signal gain amplitude is the net change in acoustic feedback parameters before and after the synchronous mutation event, such as the net decrease in acoustic attenuation, reflecting the improvement in medium density and connectivity brought about by solid-phase network formation at the microstructural level. The critical network formation characteristic parameters are the final combined data generated in this step, with a data structure of a triplet or three-dimensional vector containing critical time, torque surge amplitude, and acoustic gain amplitude. Its function is to provide a concise and crucial set of quantitative indicators for the final mortar performance evaluation.

[0069] For example, the synchronization abrupt change event point identified in the previous step is at 96 minutes. The system first locks onto this time point and calculates the critical time to be 96 minutes. Next, the system analyzes the torque data. At 94 minutes and 95 minutes before the synchronization abrupt change event point, the torque values ​​are 4.2 N·m and 4.5 N·m, respectively, averaging a pre-jump torque baseline of 4.35 N·m. At 97 minutes and 98 minutes after the event point, the torque values ​​stabilize at 8.2 N·m and 8.3 N·m, respectively, averaging a post-jump peak torque of 8.25 N·m. Therefore, the torque signal jump amplitude is 8.25 - 4.35 = 3.9 N·m. Similarly, analyzing the acoustic attenuation data, the attenuation values ​​before the event point (94 and 95 minutes) are 6.5 dB and 6.0 dB, respectively, averaging a pre-jump acoustic signal baseline of 6.25 dB. After the event points (97th and 98th minutes), the attenuation values ​​stabilized at 2.0 dB and 1.8 dB, respectively, resulting in an average peak acoustic signal of 1.9 dB after the gain. Therefore, the acoustic signal gain amplitude is 6.25 - 1.9 = 4.35 dB. Finally, the system combines the critical time of 96 minutes, the torque gain amplitude of 3.9 N·m, and the acoustic gain amplitude of 4.35 dB to generate the critical network formation characteristic parameters (96 minutes, 3.9 N·m, 4.35 dB).

[0070] The evaluation report generation module compares the critical network formation characteristic parameters with a preset mortar standard performance database to generate a mortar performance evolution evaluation report. The mortar standard performance database pre-stores the correlation between the critical network formation characteristic parameters of multiple sets of benchmark mortars and their corresponding known macroscopic performance indicators.

[0071] It should be noted that generating the mortar performance evolution evaluation report is the final step in interpreting and applying the critical network formation characteristic parameters extracted in the previous step. First, the system inputs the critical network formation characteristic parameters, including critical time, torque signal rise amplitude, and acoustic signal gain amplitude, into the evaluation module. The evaluation module internally stores a pre-set mortar standard performance database. This database contains critical network formation characteristic parameters for various standard mortar mixes under the same testing conditions, as well as performance judgment benchmark values ​​associated with these characteristic parameters. The system then compares and analyzes the characteristic parameters obtained in this test with the data in the database.

[0072] It should also be noted that the preset mortar standard performance database is established through the following steps: First, multiple sets of benchmark mortar formulations with known or standard-measured physical and mechanical properties (such as setting time, compressive strength, and flexural strength) are selected; second, the detection system and method disclosed in this invention are used to test each of the above-mentioned benchmark mortar formulations to obtain their respective critical network formation characteristic parameters (i.e., critical time, torque surge amplitude, and acoustic gain amplitude); finally, the known physical and mechanical properties of the benchmark mortar formulations are associated with their corresponding critical network formation characteristic parameters to establish a mapping relationship, thereby constructing the database. Specifically, the database contains at least a series of data entries, each data entry including at least: an identifier of a benchmark mortar formulation, the critical time corresponding to the formulation, the torque signal surge amplitude, the acoustic signal gain amplitude, and one or more macroscopic performance indicators measured under standard curing conditions, such as '28-day compressive strength' and 'early crack resistance grade'. The 'time benchmark,' 'torque benchmark,' and 'acoustic benchmark' in the preset mortar standard performance database are not single fixed values, but rather data ranges or average values ​​of one or more similar benchmark mortar formulations selected from the database based on the intended use or component type of the mortar to be evaluated. For example, if the mortar to be tested is thermal insulation mortar, data from multiple standard thermal insulation mortar formulations are selected from the database as comparison benchmarks.

[0073] In a specific embodiment of the present invention, the specific steps for generating a mortar performance evolution evaluation report include: comparing the critical time with the time benchmark in the preset mortar standard performance database to determine the network overlap efficiency.

[0074] The amplitude of the torque signal is compared with the torque benchmark in the preset mortar standard performance database to determine the contribution of early strength.

[0075] The gain amplitude of the acoustic signal is compared with the acoustic benchmark in the preset mortar standard performance database to determine the uniformity of the microstructure.

[0076] It should be noted that, subsequently, the system performs a qualitative or semi-quantitative assessment of the mortar performance tested based on a set of built-in judgment rules. The judgment rules are as follows: The critical time is compared with the preset first time reference value in the mortar standard performance database. When the critical time is less than or equal to the first time reference value, it is judged as network overlap efficiency, indicating that the modified expanded vermiculite can quickly form an effective support structure; The amplitude of the torque signal is compared with the preset first torque reference value in the mortar standard performance database. When the amplitude of the torque signal is greater than or equal to the first torque reference value, it is judged as early strength contribution, indicating that the formed skeleton network has stronger mechanical properties; The gain amplitude of the acoustic signal is compared with the preset first acoustic reference value in the mortar standard performance database. When the gain amplitude of the acoustic signal is greater than or equal to the first acoustic reference value, it is judged as microstructure uniformity, indicating that the formed solid network has fewer internal defects and better continuity.

[0077] By combining the results of network overlap efficiency, early strength contribution, and microstructure uniformity assessment, the early strength development rate and crack resistance potential of mortar are predicted, and a mortar performance evolution assessment report is generated.

[0078] It should be noted that after determining these three basic performance characteristics, the system further integrates these results to perform higher-level performance predictions. For example, determining that network overlap efficiency and early strength contribution both point to a rapid early strength development rate of the mortar; determining microstructure uniformity indicates stronger resistance to shrinkage cracking, i.e., good crack resistance potential. Finally, the system integrates all analysis and determination results to automatically generate a structured document, namely the mortar performance evolution assessment report. This report, in a graphic and textual format, clearly presents the core parameters of this test, the basic performance determinations, and the final comprehensive performance prediction, providing a basis for decision-making in material research and development or quality control.

[0079] Among these, network overlap efficiency is an indicator of the speed at which modified expanded vermiculite particles form an initial solid-phase network in mortar. Early strength contribution is an indicator of the increase in overall mechanical strength of the mortar due to the formation of the vermiculite skeleton network. Microstructure uniformity is an indicator of the uniformity of the distribution of the formed solid-phase network at the microscale and the amount of defects. Mortar early strength development rate is a prediction of the rate of strength increase in the mortar during the initial setting and hardening stage. Crack resistance potential is a prediction of the mortar's ability to resist cracking caused by volume shrinkage during hardening and drying.

[0080] Reference Figure 2The second aspect of the present invention provides a method for testing the performance of modified expanded vermiculite cement mortar, comprising: S1, preparing a force-acoustic coupling sensing probe, wherein the force-acoustic coupling sensing probe integrates an ultrasonic transceiver module and has a non-smooth micron-scale array structure that matches the average particle size of the modified expanded vermiculite particles.

[0081] S2. Immerse the force-acoustic coupling sensing probe into the modified expanded vermiculite cement mortar that has just been stirred and is in a fluid state. Drive the force-acoustic coupling sensing probe at a low speed and activate the ultrasonic transceiver module to obtain the initial state reference signal. The low speed is defined as a rotation speed that is sufficient to sense rheological properties but insufficient to produce a centrifugal separation effect.

[0082] S3. Starting from the initial state reference signal, during the hydration and hardening process of cement mortar, the force-acoustic coupling induction probe is continuously driven to rotate at low speed and transmit and receive sound waves, collecting real-time dynamic signal sequences that include the evolution of mechanical response and acoustic characteristics.

[0083] S4. In a real-time dynamic signal sequence, by monitoring the rate of change of mechanical response and acoustic characteristics, identify the synchronous abrupt change event point where a sharp increase in mechanical signal and a sharp increase in acoustic signal occur simultaneously. The sharp increase in mechanical signal and the sharp increase in acoustic signal refer to both mechanical signal and acoustic signal undergoing a step change.

[0084] S5. Based on the position and signal changes of synchronous mutation event points in the real-time dynamic signal sequence, extract the critical network to form feature parameters.

[0085] S6. Compare the critical network formation characteristic parameters with the preset mortar standard performance database to generate a mortar performance evolution evaluation report. The mortar standard performance database pre-stores the correlation between the critical network formation characteristic parameters of multiple sets of benchmark mortars and their corresponding known macroscopic performance indicators.

[0086] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, and all such modifications or additions should fall within the protection scope of the present invention.

Claims

1. A performance testing system for modified expanded vermiculite cement mortar, characterized in that, include: The sensing probe fabrication module fabricates a force-acoustic coupled sensing probe. The force-acoustic coupled sensing probe integrates an ultrasonic transceiver module and has a non-smooth micron-scale array structure that matches the average particle size of the modified expanded vermiculite particles. The initial state reference signal acquisition module immerses the force-acoustic coupling sensing probe into the modified expanded vermiculite cement mortar that has just been stirred and is in a fluid state. The initial state reference signal is acquired by driving the force-acoustic coupling sensing probe to rotate at a low speed and activating the ultrasonic transceiver module. The low speed is defined as a rotation speed that is sufficient to sense rheological properties but insufficient to produce a centrifugal separation effect. The real-time dynamic signal sequence acquisition module, starting from the initial state reference signal, continuously drives the force-acoustic coupling induction probe to rotate at low speed and transmit and receive sound waves during the hydration and hardening process of cement mortar, and acquires a real-time dynamic signal sequence that includes the evolution of mechanical response and acoustic characteristics. The synchronous mutation event point identification module identifies synchronous mutation event points in a real-time dynamic signal sequence by monitoring the rate of change of mechanical response and acoustic characteristics. The synchronous mutation event points in which a sudden increase in mechanical signal and a sudden increase in acoustic signal occur simultaneously refer to a step change in both mechanical signal and acoustic signal. The feature parameter extraction module extracts feature parameters from the critical network based on the position and signal changes of synchronous mutation event points in the real-time dynamic signal sequence. The evaluation report generation module compares the critical network formation characteristic parameters with a preset mortar standard performance database to generate a mortar performance evolution evaluation report. The mortar standard performance database pre-stores the correlation between the critical network formation characteristic parameters of multiple sets of benchmark mortars and their corresponding known macroscopic performance indicators.

2. The modified expanded vermiculite cement mortar performance testing system according to claim 1, characterized in that: The specific steps for preparing the force-acoustic coupling sensing probe include: Obtain the average particle size of the modified expanded vermiculite particles; The probe body is made of a metal material with high strength and acoustic conductivity. On the surface of the probe body, a non-smooth micron-scale array structure is formed based on the average particle size of the modified expanded vermiculite particles, so as to achieve the wedging and locking of the modified expanded vermiculite particles and the non-smooth micron-scale array structure, thereby transforming the formation of the micro-locking state into changes in mechanical and acoustic signals that can be sensed by the force-acoustic coupling sensing probe. An ultrasonic transceiver module is integrated into the non-contact end of the probe body to prepare a force-acoustic coupling sensing probe.

3. The modified expanded vermiculite cement mortar performance testing system according to claim 1, characterized in that: The specific steps for obtaining the initial state reference signal by rotating the driving force-acoustic coupling sensing probe at low speed and activating the ultrasonic transceiver module include: The drive command is received to make the force-acoustic coupling sensing probe rotate at a constant low speed in the modified expanded vermiculite cement mortar; The initial torque value experienced by the force-acoustic coupling sensing probe during rotation and the initial sound wave attenuation value received are recorded simultaneously. The initial torque value and the initial acoustic attenuation value are combined to generate the initial state reference signal.

4. The modified expanded vermiculite cement mortar performance testing system according to claim 1, characterized in that: The specific steps for acquiring real-time dynamic signal sequences that include the evolution of mechanical response and acoustic properties include: At a preset sampling frequency, the torque value and acoustic feedback parameters of the force-acoustic coupling induction probe rotation are continuously and synchronously collected. A common timestamp is added to the torque value and acoustic feedback parameters of each group of synchronously acquired force-acoustic coupling sensing probes to form torque data sequence and acoustic data sequence; The torque data sequence and the acoustic wave data sequence are aligned according to the timestamps to form a real-time dynamic signal sequence.

5. The modified expanded vermiculite cement mortar performance testing system according to claim 1, characterized in that: The specific steps for identifying the synchronous abrupt change event point where a sharp increase in mechanical signal and a sharp increase in acoustic signal occur simultaneously include: In a real-time dynamic signal sequence, calculate the rate of change of torque value and the rate of change of acoustic feedback parameters; The rate of change of torque value is compared with a preset mechanical threshold to identify sharp increases in the mechanical signal; The rate of change of the acoustic feedback parameters is compared with a preset acoustic threshold to identify a sharp increase in the acoustic signal. Match the timing of the sudden increase in mechanical signal with the timing of the sudden increase in acoustic signal, and mark the moment when the sudden increase in mechanical signal and the sudden increase in acoustic signal occur simultaneously as the synchronous mutation event point.

6. The modified expanded vermiculite cement mortar performance testing system according to claim 1, characterized in that: The specific steps for extracting the feature parameters of the critical network include: The critical time is obtained by calculating the time from the start of detection to the occurrence of the synchronous mutation event. Quantize the amplitude of the torque signal jump in the real-time dynamic signal sequence before and after the synchronous abrupt event point; Quantize the gain amplitude of the acoustic signal in the real-time dynamic signal sequence before and after the synchronous mutation event point; The critical time, the rise amplitude of the torque signal, and the gain amplitude of the acoustic signal are combined to generate a critical network that forms characteristic parameters.

7. The modified expanded vermiculite cement mortar performance testing system according to claim 6, characterized in that: The amplitude of the torque signal is obtained by calculating the difference between the average torque value during the stable phase after the synchronous mutation event point and the average torque value during the stable phase before the synchronous mutation event point; the gain amplitude of the acoustic signal is obtained by calculating the difference between the average acoustic parameter value during the stable phase before the synchronous mutation event point and the average acoustic parameter value during the stable phase after the synchronous mutation event point.

8. The modified expanded vermiculite cement mortar performance testing system according to claim 1, characterized in that: The specific steps for generating a mortar performance evolution assessment report include: The critical time is compared with the time benchmark in the preset mortar standard performance database to determine the network overlap efficiency. The amplitude of the torque signal is compared with the torque benchmark in the preset mortar standard performance database to determine the early strength contribution. The gain amplitude of the acoustic signal is compared with the acoustic benchmark in the preset mortar standard performance database to determine the uniformity of the microstructure. By combining the results of network overlap efficiency, early strength contribution, and microstructure uniformity assessment, the early strength development rate and crack resistance potential of mortar are predicted, and a mortar performance evolution assessment report is generated.

9. A method for testing the performance of modified expanded vermiculite cement mortar, characterized in that, include: S1. Prepare a force-acoustic coupling sensing probe. The force-acoustic coupling sensing probe integrates an ultrasonic transceiver module and has a non-smooth micron-scale array structure that matches the average particle size of the modified expanded vermiculite particles. S2. Immerse the force-acoustic coupling sensing probe into the modified expanded vermiculite cement mortar that has just been stirred and is in a fluid state. Drive the force-acoustic coupling sensing probe at a low speed and activate the ultrasonic transceiver module to obtain the initial state reference signal. The low speed is defined as a rotation speed that is sufficient to sense rheological properties but insufficient to produce a centrifugal separation effect. S3. Starting from the initial state reference signal, during the hydration and hardening process of cement mortar, the force-acoustic coupling induction probe is continuously driven to rotate at low speed and transmit and receive sound waves, and real-time dynamic signal sequences containing the evolution of mechanical response and acoustic characteristics are collected. S4. In a real-time dynamic signal sequence, by monitoring the rate of change of mechanical response and acoustic characteristics, identify the synchronous abrupt change event point where a sharp increase in mechanical signal and a sharp increase in acoustic signal occur simultaneously. The sharp increase in mechanical signal and the sharp increase in acoustic signal refer to both mechanical signal and acoustic signal undergoing a step change. S5. Based on the position and signal changes of synchronous mutation event points in the real-time dynamic signal sequence, extract the critical network to form feature parameters; S6. Compare the critical network formation characteristic parameters with the preset mortar standard performance database to generate a mortar performance evolution evaluation report. The mortar standard performance database pre-stores the correlation between the critical network formation characteristic parameters of multiple sets of benchmark mortars and their corresponding known macroscopic performance indicators.

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