A testing method implemented by a multi-parameter integrated testing platform for cement-based materials

Abstract

The present invention discloses a test method implemented by a multi-parameter integrated test platform for cement-based materials. Currently, there is a lack of standardized and accurate test tools and related evaluation methods that can simultaneously obtain multiple early performances of cement-based materials. In the present invention, a containing tube is vertically arranged on a base, the inner cavity of the containing tube is a filling cavity for matching the test slurry, a metal disc is arranged in the filling cavity, the metal disc is closely attached to the upper surface of the test slurry, a vertical support is vertically arranged on the base, a top block is arranged at the upper end of the vertical support, the top block is directly above the metal disc, a displacement sensor facing the metal disc is arranged on the bottom surface of the top block, a lifting and adjusting component is arranged on the vertical support, the lifting and adjusting component is connected to the displacement sensor, and the displacement sensor makes a reciprocating motion toward or away from the metal disc along the height direction of the vertical support driven by the lifting and adjusting component.

Description

Technical Field

[0001] The invention specifically relates to a testing method implemented by a multi-parameter integrated testing platform for cement-based materials, and belongs to the technical field of civil engineering. Background Art

[0002] Autogenous shrinkage of cement-based materials refers to the shrinkage deformation produced when there is no water exchange with the environment, which is particularly significant in low water-cement ratio and large-volume concrete. Autogenous shrinkage is mainly determined by two parameters: shrinkage driving force and self-deformation resistance. Internal relative humidity and electrical signals (resistivity, impedance) can be used to evaluate the autogenous shrinkage driving force and deformation resistance of cement-based materials, respectively. Since autogenous shrinkage is an important indicator for evaluating the volume stability of cement-based materials and is the basis and prerequisite for early age cracking calculations, continuous monitoring of autogenous shrinkage and related influencing factors is particularly important for guiding the application of cement-based materials.

[0003] Commonly used shrinkage test methods include linear contact and non-contact methods, volumetric methods, etc. The linear method is relatively simpler than the volumetric method, but the linear contact test is prone to errors due to differences in test positions and testers each time, and it is impossible to test the shrinkage of cement-based materials in the initial plastic state of casting, and it is even more impossible to conduct continuous high-precision testing and collection of data.

[0004] As free water is continuously consumed during cement hydration, the internal relative humidity will gradually decrease, resulting in the formation of a capillary meniscus in the capillary, which generates capillary pressure to compress the matrix and cause shrinkage. Monitoring the internal relative humidity can be used to analyze the development of the self-shrinkage driving force. Usually, before testing the internal relative humidity, a small hole for the temperature and humidity sensor to be inserted needs to be reserved inside the specimen. Since the slurry is still in a plastic state in the early stage of pouring cement-based materials, improper handling of the reserved holes will make it impossible to test the development of the early internal relative humidity, and may even damage the temperature and humidity sensor.

[0005] The cement hydration process consumes free water and forms hydration products, which will affect the ion concentration of the internal pore solution and the density of the matrix, thereby changing the resistivity of cement-based materials. However, simple, long-term, and non-destructive monitoring methods for the resistivity of cement-based materials have not yet been effectively unified.

[0006] In summary, there are still some defects in the testing of autogenous shrinkage and related parameters that need to be solved. In addition, a single parameter test often cannot accurately reflect the autogenous shrinkage deformation and crack formation mechanism of cement-based materials. Therefore, the construction of a multi-parameter testing platform has important practical value and scientific significance for the application guidance of cement-based materials. However, there is currently a lack of standardized and accurate testing tools and related evaluation methods that can simultaneously obtain multiple early performances of cement-based materials. Summary of the invention

[0007] In order to solve the problems mentioned in the above background technology, the purpose of the present invention is to provide a testing method implemented by a multi-parameter integrated testing platform for cement-based materials.

[0008] A cement-based material multi-parameter integrated testing platform comprises a square mold box, a data acquisition instrument and at least one debugging column, wherein the square mold box and the at least one debugging column are respectively connected to the data acquisition instrument, and the at least one debugging column and the square mold box are both filled with test slurry;

[0009] The debugging column includes a containing tube, a vertical support, a base, a top block, a metal disc, a displacement sensor and a lifting and debugging member. The containing tube is vertically arranged on the base. The inner cavity of the containing tube is a filling cavity for matching the test slurry. The metal disc is arranged in the filling cavity. The metal disc is tightly attached to the upper surface of the test slurry. The vertical support is vertically arranged on the base. A top block is arranged on the upper end of the vertical support. The top block is directly above the metal disc. A displacement sensor facing the metal disc is arranged on the bottom surface of the top block. A lifting and debugging member is arranged on the vertical support. The lifting and debugging member is connected to the displacement sensor. Driven by the lifting and debugging member, the displacement sensor makes a reciprocating motion toward or away from the metal disc along the height direction of the vertical support.

[0010] As a preferred solution: the top of the square mold box is an open end, the test slurry filled in the square mold box is a cement-based material layer, the side wall of the square mold box is processed with a through hole, an isolation tube body is arranged in the square mold box, the isolation tube body is arranged in the test slurry, an electrode is buried in the test slurry, one end of the isolation tube body passes through the through hole and is connected to a data acquisition instrument; the data acquisition instrument is arranged on the outer wall of the square mold box, a data display screen is arranged on the top surface of the data acquisition instrument, and an SD card is arranged in the data acquisition instrument.

[0011] As a preferred solution: a temperature and humidity sensor is arranged in the isolation tube.

[0012] As a preferred solution: a breathable membrane is provided at the other end of the isolation tube body, and the isolation tube body is a PVC hose.

[0013] As a preferred solution: a plastic film is arranged in the debugging column, the plastic film is arranged between the debugging column and the test slurry, the bottom surface of the plastic film is closely attached to the upper surface of the test slurry, and the bottom surface of the metal disc is closely attached to the top surface of the plastic film.

[0014] As a preferred solution: when the number of the debugging column is one, the debugging column is vertically arranged on the top of the square mold box, and the filling cavity is connected with the interior of the square mold box.

[0015] As a preferred solution: when the number of the debugging column is one, the debugging column is vertically arranged on the outer wall of the square mold box, and the filling cavity is connected with the interior of the square mold box.

[0016] As a preferred solution: when there are four debugging columns, the four debugging columns are vertically arranged in parallel at the four end corners of the square mold box, and the filling cavity of each debugging column is connected to the interior of the square mold box.

[0017] As a preferred solution: the data acquisition instrument is arranged on the outer wall of the square mold box, a data display screen is arranged on the top surface of the data acquisition instrument, and an SD card is arranged in the data acquisition instrument.

[0018] A multi-parameter integrated testing method for cement-based materials is implemented using a multi-parameter integrated testing platform for cement-based materials described in Specific Implementations 1, 2, 3, 4, 5, 6, 7 or 8. The multi-parameter integrated testing method for cement-based materials comprises the following steps:

[0019] Mold preparation stage: place the electrodes and temperature and humidity sensors inside the square mold box in advance;

[0020] Casting stage: the mixed cement-based material is cast in two layers in a square mold box. After the square mold box is placed on a vibration table, the first cement-based material layer is molded into the square mold box. After the cement-based material is compacted to a uniform and dense state by tamping up and down with a tamping rod and vibrating on a vibration table, the remaining slurry is cast to form a second cement-based material layer. Similarly, after casting a double layer of cement-based material layers in the containing tube, a plastic film and a metal disc are placed on the upper surface of the test slurry in sequence.

[0021] Data collection stage: connect the various sensor interfaces exported from the square mold box to the data acquisition instrument, and then connect the power supply of the equipment to ensure that the vertical distance between the displacement sensor and the metal disc in the debugging column is continuously less than 150μm during the data collection process;

[0022] Data acquisition and storage: The test time data, resistance data, test slurry relative humidity data and test slurry self-shrinkage data collected by the data acquisition instrument are stored in the SD card in the data acquisition instrument. After reaching the predetermined collection period, the collected data are centrally exported from the SD card for subsequent analysis and calculation process;

[0023] As a preferred solution, the collected data is centrally exported from the SD card (11) and the subsequent analysis and calculation process is as follows:

[0024] According to the early shrinkage deformation theory of cement-based materials, the total deformation ε is obtained by formula 1, which is composed of the elastic deformation ε e and creep ε creep Composition relationship, where ε e It can be obtained by formula 2, combining the saturation degree S and capillary pressure σ cap , the bulk modulus K of the matrix is ​​quantitatively described, and ε creep Then the increment of elastic deformation Δ can be used from formula 3elas , zero point of autogenous contraction τ k , the ratio of hydration degree The liquid-to-solid ratio ω and the relaxation factor n yield:

[0025] Formula 1: ε=ε e +ε creep ;

[0026] Formula 2:

[0027] Formula 3:

[0028] In formula 2, K s is the solid phase bulk modulus, in GPa. Since the main component of cement-based materials is silicate phase, the bulk modulus of solid silicate is taken as 44 GPa. According to Formula 4, the function K, that is, the bulk modulus K of the matrix, is obtained. The bulk modulus K of the matrix is ​​a function of the material elastic modulus E and Poisson's ratio (v), where the material elastic modulus E is in GPa, and the Poisson's ratio of cement-based materials is usually taken as 0.2; in Formula 3, n is usually taken as a constant: 0.30;

[0029] Formula 4:

[0030] According to the real-time monitoring of cement-based material resistance R, internal relative humidity RH, temperature Temp data, S and σ in formula 2 are estimated. cap , K and τ in formula 3 k , ω, and then use Formula 2 to determine the increment of elastic deformation at different time intervals Δ elas , combined with the early deformation monitoring value of cement materials and formula 1, the inverse analysis of the elastic deformation ε of cement-based materials is established e and creep during autogenous shrinkage creep The algorithm of development law includes the following parts:

[0031] Part 1: According to Formula 1, Formula 2 and Formula 3, the parameters that need to be determined in initializing the early shrinkage model parameters of cement materials are determined: S, σ cap , K and τ in Eq. k , ω;

[0032] Part 2: Read the real-time monitoring data of the resistance R and temperature Temp of cement-based materials, and use formula 5 to normalize the resistance data to 20°C;

[0033] Formula 5: R 20℃ =R temp [1+α(Temp-20)];

[0034] In Formula 5, R20℃ is the resistance of the material at 20°C, ohm; R temp is the resistance of the material at Temp℃, ohm; α is the temperature regression coefficient;

[0035] Part 3: Read the real-time monitoring data of relative humidity RH and temperature Temp of cement-based materials. According to the following steps, the internal RH data of the monitored cement-based materials is normalized to 20°C to remove the influence of temperature on the relative humidity test results. Specifically, it includes three steps:

[0036] Step 1: Calculate the saturated vapor pressure of water vapor at the measured temperature based on the measured temperature and formula 6:

[0037] Formula 6:

[0038] In formula 6, P vsT is the saturated vapor pressure of water vapor at the measured temperature, in Pa; e is a natural constant, 2.718; T is the measured Kelvin temperature, T = t + 273.15, K, t is degrees Celsius, ℃; A, B, C, D, E, F are constants, A is -5800.2206, B is 1.3914993, C is -0.048640239, D is 0.41764768×10 -4 , E is -0.14452093×10 -7 , F is 6.5459673;

[0039] Step 2: Based on the measured relative humidity data, calculate the water vapor pressure in the microenvironment of cement-based materials according to Formula 7:

[0040] Formula 7: p vT =p vsT ×RH T ;

[0041] In formula 7, p vT The unit is Pa; RH is the water vapor pressure in the measured microenvironment. T Relative humidity in the measured microenvironment, unit: %;

[0042] Step 3: Convert the relative humidity of the cement-based material microenvironment to the relative humidity at 20°C:

[0043] Formula 8:

[0044] In formula 8, p v20℃ is the saturated vapor pressure of water vapor at 20°C, 2.3388×10 3 Pa; RH 20℃ is the relative humidity of the microenvironment at 20°C, in %;

[0045] Part 4: Establishing RH using Formula 9 20℃ Relationship with S:

[0046] Formula 9: S = ηlog(RH 20℃ )+a;

[0047] In formula 9, η and a are regression constants;

[0048] Part 5: Using Formula 10, Formula 11 and Formula 12, the internal relative humidity RH 20℃ Estimation of σ cap ;

[0049] Formula 10:

[0050] Formula 11:

[0051] Formula 12:

[0052] In Formula 10 to Formula 12, V w is the molar volume of the pore solution, m 3 / mol, ignoring the effect of ions on the molar volume of the solution, the molar volume of water is 18.02×10 -6 m 3 / mol; R is the ideal gas constant, which is 8.314 J / (mol·K); T is the experimental temperature, K, which is 293.15 K at 20°C; RH is the relative humidity corresponding to the meniscus formed in the capillary pores, %; cosθ is the experimentally measured contact angle of the substrate surface, which is 120°;

[0053] Part 6: According to Formula 13, R 20℃ The relative change estimates E, and K is determined by equation 4. The calculation process is:

[0054] Formula 13:

[0055] In Formula 13, R 20℃,0 is the initial resistance value; R 20℃,t is the estimated resistance value; G and κ are regression constants;

[0056] Part 7: According to Formula 2, the elastic deformation ε in the total deformation e Part of it is expressed by formula 14:

[0057] Formula 14:

[0058]

[0059] Part 8: Estimating τ using the mutation points of the RH and R curves k ;

[0060] Part 9: Estimation of the hydration ratio using the relative change of R according to Formula 15 The calculation process is:

[0061] Formula 15:

[0062] In formula 15, m and n are regression constants;

[0063] Part 10: According to Formula 16, the liquid-solid ratio ω is estimated using the relative change of R. The calculation process is:

[0064] Formula 16:

[0065] In formula 16, C and u are regression constants;

[0066] Part 11: According to Formula 3, the elastic deformation ε in the total deformation creep Part of it is expressed by formula seventeen:

[0067] Formula 17:

[0068]

[0069] Part 12: According to Formula 14 and Formula 17, combined with the measured data of early deformation of cement-based materials and the shrinkage deformation model, and then according to Formula 14, calculate the increment Δ of elastic deformation at intervals of 10min, 30min, 60min, and 120min elas , respectively, using the multivariate nonlinear regression method to estimate η, a, G, κ, m, n, C, and u;

[0070] Part 13: Test the residual distribution characteristics, residual extreme values, and residual distribution characteristics of the regression model with different time intervals, systematically analyze the impact of time interval on the reliability and accuracy of regression analysis, and determine the optimal time interval;

[0071] Part 14: Based on Formula 14 and Formula 17, establish the elastic deformation ε of cement-based materials e and creep during autogenous shrinkage creep The change process over time can predict the risk of early shrinkage and cracking of cement-based materials, and provide analytical data support for further analysis of the early performance evolution of cement-based materials.

[0072] Compared with the prior art, the present invention has the following beneficial effects:

[0073] 1. The multi-parameter integrated testing platform for cement-based materials in the present invention can realize the real-time monitoring process of simultaneously obtaining the three parameter data of autogenous shrinkage, internal relative humidity and resistance of the test slurry through the cooperation between the square mold box, the data acquisition instrument and at least one debugging column. The testing process ensures the consistency of the environmental conditions for the testing of each parameter and effectively reduces the accidental errors caused by batch testing of parameters.

[0074] Second, the integrated structure of the debugging column and the square mold box in the present invention can simultaneously realize the process of acquiring multiple types of data of small and large test slurries, among which the structural form of the debugging column itself can realize the vertical measurement of small volumes, which is more conducive to the acquisition of autogenous shrinkage data. The square mold box is the process of acquiring the internal relative humidity and resistance data of the large test slurry. Various parameter data are acquired simultaneously based on the same test slurry, which is more conducive to the accurate acquisition of the three parameter data of autogenous shrinkage, internal relative humidity and resistance.

[0075] 3. The test platform formed by the cooperation between the square mold box, the data acquisition instrument and at least one debugging column of the present invention is an integral, partially disassembled test platform structure. After the test, the slurry to be tested hardens and is easily disassembled, which facilitates the cleaning process of the blind area where the test slurry is easily accumulated, and can also be reused.

[0076] 4. The testing principle of the multi-parameter integrated testing method for cement-based materials in the present invention is that autogenous shrinkage deformation is a testing process in which capillary pressure and anti-deformation ability work together. The internal relative humidity data obtained during the testing process can be used to evaluate the development of internal capillary pressure during the autogenous shrinkage process, and the resistance data obtained can be used to evaluate the development of internal stiffness during the autogenous shrinkage process. By combining the internal relative humidity, resistance, and autogenous shrinkage data, the autogenous shrinkage change mechanism of cement-based materials can be better analyzed.

[0077] 5. The testing principle of the multi-parameter integrated testing method for cement-based materials in the present invention is based on the theory of early autogenous shrinkage of cement-based materials. By deriving the early elastic shrinkage and creep calculation equations, based on the measured total shrinkage value, internal relative humidity, resistivity and other real-time data, the multivariate nonlinear regression method is used to accurately calculate the elastic deformation, creep and other related parameters that are difficult to obtain experimentally. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] For ease of explanation, the present invention is described in detail with reference to the following specific embodiments and accompanying drawings.

[0079] Figure 1 This is a first main structural schematic diagram of the multi-parameter integrated testing platform for cement-based materials in the present invention;

[0080] Figure 2It is a second main structural schematic diagram of the multi-parameter integrated testing platform for cement-based materials in the present invention;

[0081] Figure 3 It is a three-dimensional structural schematic diagram of the connection relationship between the first group of square templates and the debugging column;

[0082] Figure 4 A schematic diagram of the side cross-sectional structure of the connection relationship between the first group of square formwork and the debugging column;

[0083] Figure 5 It is a first three-dimensional structural schematic diagram of the connection relationship between the square mold box and the debugging column, and the number of debugging columns set in the figure is one;

[0084] Figure 6 A second three-dimensional structural schematic diagram of the connection relationship between the square mold box and the debugging column, in which a plurality of debugging columns are provided;

[0085] Figure 7 This is a schematic diagram of the use status of the multi-parameter integrated testing platform for cement-based materials;

[0086] Figure 8 A three-dimensional structural schematic diagram of the connection relationship between the isolation tube body and the displacement sensor;

[0087] Fig. 9 This is a schematic diagram of the working principle of the multi-parameter integrated testing platform for cement-based materials;

[0088] Fig.10 A coordinate diagram of the autogenous shrinkage data obtained by the test method of the present invention;

[0089] Fig.11 This is a graph of internal temperature results obtained by the test method of the present invention;

[0090] Fig.12 The figure is a result diagram of the internal temperature of the test slurry obtained by the test method of the present invention;

[0091] Fig.13 It is a coordinate diagram of the internal resistivity ratio data of the test slurry obtained by the test method of the present invention.

[0092] In the figure: 1-square mold box; 2-data acquisition instrument; 3-debugging column; 3-1-containing tube; 3-2-vertical support; 3-3-base; 3-4-top block; 3-5-metal disc; 3-6-filling cavity; 3-7-displacement sensor; 3-8-lifting and debugging piece; 5-isolating tube body; 6-electrode; 7-temperature and humidity sensor; 8-breathable membrane; 9-data display screen; 10-plastic film; 11-SD card; 12-square template; 13-through hole; 14-jack; 20-test slurry. DETAILED DESCRIPTION

[0093] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that the present invention can be implemented, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0094] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0095] Specific implementation method 1: Combination Figures 1 to 13 The present embodiment is described. In the present embodiment, the multi-parameter integrated testing platform for cement-based materials includes a square mold box 1, a data acquisition instrument 2 and at least one debugging column 3. The square mold box 1 and the at least one debugging column 3 are respectively connected to the data acquisition instrument 2. The at least one debugging column 3 and the square mold box 1 are both filled with a test slurry 20. The test slurry 20 filled and injected into the square mold box 1 is a large-volume test slurry, and the test slurry 20 filled and injected into the debugging column 3 is a part of the large-volume test slurry, forming a local small-volume test slurry.

[0096] In the present embodiment, the top of the square mold box 1 is an open end, and the square mold box 1 is filled with a test slurry 20. The specific structure of the square mold box 1 is that it consists of five square templates 12, four of the five square templates 12 are vertically enclosed in sequence to form a square frame, and the remaining square template 12 of the five square templates 12 serves as the bottom of the square frame, and the four edges of the square template 12 are respectively connected to the edges of the bottom of the square frame, and the bottom of the square frame is fixedly connected to the square template 12 as a whole to form a mold structure with an open top, and a large square filling cavity that matches the test slurry 20 is formed between the bottom of the square frame and the inner wall of the square template 12.

[0097] The test slurry 20 in this embodiment is specifically a cement-based material slurry.

[0098] In this embodiment, the square frame is processed with a through hole 13 along its thickness direction, which is used to bury relevant sensors inside the test slurry 20. Specifically, the test slurry 20 is specifically a cement-based material layer. The through hole 13 of the square mold box 1 provides an entry and exit position for the isolation tube body 5 to pass through. The through hole 13 is a circular hole, and its inner diameter is less than one-fifth of the length of the square template 12. The isolation tube body 5 is a hollow tube body, and its outer diameter is smaller than the inner diameter of the through hole 13. The difference between the two is less than or equal to one-tenth of the through hole 13, thereby ensuring a tightly coaxial penetration process. The isolation tube body 5 is arranged in the test slurry 20, and an electrode 6 is buried in the test slurry 20. One end of the isolation tube body 5 passes through the through hole 4 and is connected to the data acquisition instrument 2.

[0099] Furthermore, a temperature and humidity sensor 7 is provided in the isolation tube body 5. The temperature and humidity sensor 7 is an existing sensor, and its working principle is the same as that of the existing temperature and humidity sensor.

[0100] Furthermore, a breathable membrane 8 is provided at the other end of the isolation tube body 5 .

[0101] Furthermore, the isolation tube body 5 is a PVC hose.

[0102] In this embodiment, the square template 12 is processed with four insertion holes 14 along its thickness direction, and the four insertion holes 14 are arranged in a square matrix, which are evenly distributed on the square template 12 to provide insertion positions for the electrodes 6. The electrodes 6 are existing strip electrodes, and their working principle is the same as that of existing strip electrodes.

[0103] In this embodiment, the debugging column 3 includes a accommodating tube 3-1, a vertical support member 3-2, a base 3-3, a top block 3-4, a metal disc 3-5, a displacement sensor 3-7 and a lifting debugging member 3-8. The accommodating tube 3-1 is vertically arranged on the base 3-3. The inner cavity of the accommodating tube 3-1 is a filling cavity 3-6 for matching the test slurry 20. The metal disc 3-5 is arranged in the filling cavity 3-6. The metal disc 3-5 is tightly attached to the upper surface of the test slurry 20. The vertical support member 3-2 is vertically arranged on the base 3-3. A top block 3-4 is provided at the upper end of the support member 3-2, and the top block 3-4 is directly above the metal disc 3-5. A displacement sensor 3-7 facing the metal disc 3-5 is provided on the bottom surface of the top block 3-4. A lifting and adjusting member 3-8 is provided on the vertical support member 3-2, and the lifting and adjusting member 3-8 is connected to the displacement sensor 3-7. Driven by the lifting and adjusting member 3-8, the displacement sensor 3-7 makes a reciprocating motion toward or away from the metal disc 3-5 along the height direction of the vertical support member 3-2.

[0104] Among them, displacement sensor 3-7 is a high-precision wireless displacement sensor.

[0105] Among them, the lifting and adjusting member 3-8 is an existing lifting and adjusting member, which specifically includes a gear, a rack and a knob. The top of the vertical support member 3-2 is processed with a vertical groove body, and a rack is arranged in the vertical groove body. One side of the rack is slidably matched with the inner wall of the groove of the vertical groove body, and the other side of the rack is meshed with a gear. The gear is matched with a knob, and the knob is arranged on the outer wall of the vertical support member 3-2. The top of the rack is fixedly connected with a top block 3-4. The working principle of the lifting and adjusting member 3-8 is as follows:

[0106] Turn the knob clockwise, and the rotation of the knob drives the gear to rotate synchronously, and the rotation of the gear drives the rack to move vertically upward. When the rack moves vertically upward, it drives the top block 3-4 to rise synchronously, thereby increasing the distance between the probe of the displacement sensor 3-7 and the top of the containing tube 3-1. Similarly, turn the knob counterclockwise, and the rotation of the knob drives the gear to rotate synchronously, and the rotation of the gear drives the rack to move vertically downward. When the rack moves vertically downward, it drives the top block 3-4 to fall synchronously, thereby decreasing the distance between the probe of the displacement sensor 3-7 and the top of the containing tube 3-1.

[0107] Specific implementation method 2: This implementation method is a further limitation of the specific implementation method 1. Figure 1 As shown, a structural form of the cement-based material multi-parameter integrated testing platform in this embodiment is a square mold box 1, a data acquisition instrument 2 and at least one debugging column 3. When the number of the debugging column 3 is one, an arrangement form of the debugging column 3 is: the debugging column 3 is vertically arranged on the top of the square mold box 1, and the filling cavity 3-6 is connected with the interior of the square mold box 1, thereby forming a small-volume and large-volume synchronous data testing acquisition process from top to bottom in the vertical direction.

[0108] The debugging column 3 includes a containing tube 3-1, a vertical support 3-2, a base 3-3, a top block 3-4, a metal disc 3-5, a displacement sensor 3-7 and a lifting debugging member 3-8. The containing tube 3-1 is vertically arranged on the base 3-3. The inner cavity of the containing tube 3-1 is a filling cavity 3-6 for matching the test slurry 20. The metal disc 3-5 is arranged in the filling cavity 3-6. The metal disc 3-5 is tightly attached to the upper surface of the test slurry 20. The vertical support 3-2 is vertically arranged on the base 3-3. A top block 3-4 is provided at the upper end of the support member 3-2, and the top block 3-4 is directly above the metal disc 3-5. A displacement sensor 3-7 facing the metal disc 3-5 is provided on the bottom surface of the top block 3-4. A lifting and adjusting member 3-8 is provided on the vertical support member 3-2, and the lifting and adjusting member 3-8 is connected to the displacement sensor 3-7. Driven by the lifting and adjusting member 3-8, the displacement sensor 3-7 makes a reciprocating motion toward or away from the metal disc 3-5 along the height direction of the vertical support member 3-2.

[0109] Specific implementation method three: This implementation method is a further limitation of specific implementation methods one or two, combined with Figure 2 , Figure 3 and Figure 4 As shown, another structural form of the cement-based material multi-parameter integrated test platform in this embodiment is that when the number of the debugging column 3 is one, another arrangement form of the debugging column 3 is: the debugging column 3 is vertically arranged on the outer wall of the square mold box 1, and the filling cavity 3-6 is connected to the interior of the square mold box 1. The cement-based material multi-parameter integrated test platform of this structural form can realize the small-volume synchronous test process of an end corner of the large-volume test slurry 20.

[0110] The debugging column 3 includes a containing tube 3-1, a vertical support 3-2, a base 3-3, a top block 3-4, a metal disc 3-5, a displacement sensor 3-7 and a lifting debugging member 3-8. The containing tube 3-1 is vertically arranged on the base 3-3. The inner cavity of the containing tube 3-1 is a filling cavity 3-6 for matching the test slurry 20. The metal disc 3-5 is arranged in the filling cavity 3-6. The metal disc 3-5 is tightly attached to the upper surface of the test slurry 20. The vertical support 3-2 is vertically arranged on the base 3-3. A top block 3-4 is provided at the upper end of the support member 3-2, and the top block 3-4 is directly above the metal disc 3-5. A displacement sensor 3-7 facing the metal disc 3-5 is provided on the bottom surface of the top block 3-4. A lifting and adjusting member 3-8 is provided on the vertical support member 3-2, and the lifting and adjusting member 3-8 is connected to the displacement sensor 3-7. Driven by the lifting and adjusting member 3-8, the displacement sensor 3-7 makes a reciprocating motion toward or away from the metal disc 3-5 along the height direction of the vertical support member 3-2.

[0111] Specific implementation method 4: This implementation method is a further limitation of the specific implementation method 1. Figure 5 , Figure 6 and Figure 7 As shown, another structural form of the cement-based material multi-parameter integrated testing platform in this embodiment is:

[0112] When there are four debugging columns 3 , the four debugging columns 3 are vertically arranged in parallel at the four end corners of the square mold box 1 , and the filling cavity 3 - 6 of each debugging column 3 is connected to the interior of the square mold box 1 .

[0113] The third arrangement form formed by the four debugging columns 3 is that the four debugging columns 3 are arranged vertically in parallel, each debugging column 3 is vertically arranged at the outer wall of one end of the square mold box 1, and the filling cavity 3-6 is connected to the interior of the square mold box 1. The multi-parameter integrated testing platform for cement-based materials in this structural form can realize the small-volume synchronous testing process of the four end corners of the large-volume test slurry 20, increase the synchronous measurement process of the small-volume at multiple end corners, and is more conducive to the multi-position synchronous acquisition process of the relevant self-shrinkage data at the small volume, which is conducive to improving the accurate acquisition of data.

[0114] The debugging column 3 includes a containing tube 3-1, a vertical support 3-2, a base 3-3, a top block 3-4, a metal disc 3-5, a displacement sensor 3-7 and a lifting debugging member 3-8. The containing tube 3-1 is vertically arranged on the base 3-3. The inner cavity of the containing tube 3-1 is a filling cavity 3-6 for matching the test slurry 20. The metal disc 3-5 is arranged in the filling cavity 3-6. The metal disc 3-5 is tightly attached to the upper surface of the test slurry 20. The vertical support 3-2 is vertically arranged on the base 3-3. A top block 3-4 is provided at the upper end of the support member 3-2, and the top block 3-4 is directly above the metal disc 3-5. A displacement sensor 3-7 facing the metal disc 3-5 is provided on the bottom surface of the top block 3-4. A lifting and adjusting member 3-8 is provided on the vertical support member 3-2, and the lifting and adjusting member 3-8 is connected to the displacement sensor 3-7. Driven by the lifting and adjusting member 3-8, the displacement sensor 3-7 makes a reciprocating motion toward or away from the metal disc 3-5 along the height direction of the vertical support member 3-2.

[0115] Specific embodiment five: This embodiment is a further limitation of specific embodiments one, two, three or four. In this embodiment, a plastic film 10 is provided in the debugging column 3, and the plastic film 10 is provided between the debugging column 3 and the test slurry 20. The bottom surface of the plastic film 10 is tightly attached to the upper surface of the test slurry 20, and the bottom surface of the metal disc 3-5 is tightly attached to the top surface of the plastic film 10.

[0116] Specific implementation method six: This implementation method is a further limitation of specific implementation methods one, two, three, four or five. In this implementation method, the data acquisition device 2 is vertically arranged on one side outer wall of the square mold box 1 to enhance the integrated structural layout.

[0117] Specific implementation method 7: This implementation method is a further limitation of specific implementation methods 1, 2, 3, 4, 5 or 6. A data display screen 9 is provided on the top surface of the data acquisition instrument 2, and an SD card 11 is provided in the data acquisition instrument 2. The SD card 11 is an existing SD card, and its working process is the same as the working principle of the existing SD card.

[0118] Specific embodiment eight: This embodiment is a further limitation of specific embodiments one, two, three, four, five or six. There are two ways to connect the filling cavity 3-6 of the debugging column 3 with the square mold box 1:

[0119] One connection method is that the filling cavity 3-6 of the debugging column 3 is connected with the interior of the square mold box 1 to form a process of uniformly injecting the test slurry 20 at one time. This connection method involves a pouring and vibrating process with fine operation to ensure that there are no blind spots in the pouring process. After vibration, the test slurry 20 is uniform and stable at various positions inside the filling cavity 3-6 and the square mold box 1, and the air and bubbles therein are eliminated to form a tight and uniform structural form, thereby ensuring a test object with a long-lasting uniform test slurry 20, which is conducive to improving the test quality and the accuracy of obtaining relevant data.

[0120] Another connection method is that the filling cavity 3-6 of the debugging column 3 is not connected to the interior of the square mold box 1, and the same test slurry 20 is injected respectively, which is conducive to separate pouring and vibration, reduces the difficulty of pouring and vibration operations, and can also ensure the test quality and the accuracy of obtaining relevant data.

[0121] Specific implementation method nine: Combination Figures 1 to 13 The present embodiment is described. The cement-based material multi-parameter integrated testing method in the present embodiment comprises the following steps:

[0122] The multi-parameter integrated testing method for cement-based materials comprises the following steps:

[0123] Mold preparation stage: the electrodes 6 and the temperature and humidity sensor 7 are placed inside the square mold box 1 in advance;

[0124] Casting stage: the mixed cement-based material is cast in two layers in the square mold box 1 respectively. After the square mold box 1 is placed on a vibration table, the first cement-based material layer is molded into the square mold box 1. After the cement-based material is compacted to a uniform and dense state by tamping up and down with a tamping rod and vibrating on a vibration table, the remaining slurry is cast to form a second cement-based material layer. Similarly, after a double layer of cement-based material layers is cast in the containing tube 3-1, a plastic film 10 and a metal disc 3-5 are sequentially placed on the upper surface of the test slurry 20;

[0125] Data collection stage: connect the various sensor interfaces derived from the square mold box 1 to the data acquisition instrument 2, and then connect the power supply of the equipment to ensure that the vertical distance between the displacement sensor 3-7 and the metal disc 3-5 in the debugging column 3 is continuously less than 150μm during the data collection process; the data collection process is an automatic data collection process based on the electronic control cooperation of the data acquisition instrument 2 and the displacement sensor 3-7, and its automatic data collection process is the existing electronic control principle.

[0126] Data acquisition and storage: The test time data, resistance data, relative humidity data of the test slurry 20 and self-shrinkage data of the test slurry 20 collected by the data acquisition instrument 2 are stored in the SD card 11 in the data acquisition instrument 2. After reaching the predetermined collection period, the collected data are centrally exported from the SD card 11 for subsequent analysis and calculation.

[0127] Specific implementation method 10: This implementation method is a further limitation of specific implementation method 9. In this implementation method, the collected data is centrally exported from the SD card 11 and then the subsequent analysis and calculation process is as follows:

[0128] According to the early shrinkage deformation theory of cement-based materials, the total deformation ε is obtained by formula 1, which is composed of the elastic deformation ε e and creep ε creep Composition relationship, where ε e It can be obtained by formula 2, combining the saturation degree S and capillary pressure σ cap , the bulk modulus K of the matrix is ​​quantitatively described, and ε creep Then the increment of elastic deformation Δ can be used from formula 3 elas , zero point of autogenous contraction τ k , the ratio of hydration degree The liquid-to-solid ratio ω and the relaxation factor n yield:

[0129] Formula 1: ε=ε e +ε creep ;

[0130] Formula 2:

[0131] Formula 3:

[0132] In formula 2, K s is the solid phase bulk modulus, in GPa. Since the main component of cement-based materials is silicate phase, the bulk modulus of solid silicate is taken as 44 GPa. According to Formula 4, the function K, that is, the bulk modulus K of the matrix, is obtained. The bulk modulus K of the matrix is ​​a function of the material elastic modulus E and Poisson's ratio (v), where the material elastic modulus E is in GPa, and the Poisson's ratio of cement-based materials is usually taken as 0.2; in Formula 3, n is usually taken as a constant: 0.30;

[0133] Formula 4:

[0134] According to the real-time monitoring of cement-based material resistance R, internal relative humidity RH, temperature Temp data, S and σ in formula 2 are estimated. cap , K and τ in formula 3 k , ω, and then use Formula 2 to determine the increment of elastic deformation at different time intervals Δ elas, combined with the early deformation monitoring value of cement materials and formula 1, the inverse analysis of the elastic deformation ε of cement-based materials is established e and creep during autogenous shrinkage creep The algorithm of development law includes the following parts:

[0135] Part 1: According to Formula 1, Formula 2 and Formula 3, the parameters that need to be determined in initializing the early shrinkage model parameters of cement materials are determined: S, σ cap , K and τ in Eq. k , ω;

[0136] Part 2: Read the real-time monitoring data of the resistance R and temperature Temp of cement-based materials, and use formula 5 to normalize the resistance data to 20°C;

[0137] Formula 5: R 20℃ =R temp [1+α(Temp-20)];

[0138] In Formula 5, R 20 The resistance of the material at 20°C, ohm; R temp is the resistance of the material at Temp℃, ohm; α is the temperature regression coefficient;

[0139] Part 3: Read the real-time monitoring data of relative humidity RH and temperature Temp of cement-based materials. According to the following steps, the internal RH data of the monitored cement-based materials is normalized to 20°C to remove the influence of temperature on the relative humidity test results. Specifically, it includes three steps:

[0140] Step 1: Calculate the saturated vapor pressure of water vapor at the measured temperature based on the measured temperature and formula 6:

[0141] Formula 6:

[0142] In formula 6, p vsT is the saturated vapor pressure of water vapor at the measured temperature, in Pa; e is a natural constant, 2.718; T is the measured Kelvin temperature, T = t + 273.15, K, t is degrees Celsius, ℃; A, B, C, D, E, F are constants, A is -5800.2206, B is 1.3914993, C is -0.048640239, D is 0.41764768×10 -4 , E is -0.14452093×10 -7 , F is 6.5459673;

[0143] Step 2: Based on the measured relative humidity data, calculate the water vapor pressure in the microenvironment of cement-based materials according to Formula 7:

[0144] Formula 7: p vT =p vsT ×RH T ;

[0145] In formula 7, p vT The unit is Pa; RH is the water vapor pressure in the measured microenvironment. T is the measured relative humidity in the microenvironment, unit: %;

[0146] Step 3: Convert the relative humidity of the cement-based material microenvironment to the relative humidity at 20°C:

[0147] Formula 8:

[0148] In formula 8, p v20℃ is the saturated vapor pressure of water vapor at 20°C, 2.3388×10 3 Pa; RH 20℃ is the relative humidity of the microenvironment at 20°C, in %;

[0149] Part 4: Establishing RH using Formula 9 20℃ Relationship with S:

[0150] Formula 9: S = ηlog(RH 20℃ )+a;

[0151] In formula 9, η and a are regression constants;

[0152] Part 5: Using Formula 10, Formula 11 and Formula 12, the internal relative humidity RH 20℃ Estimation of σ cap ;

[0153] Formula 10:

[0154] Formula 11:

[0155] Formula 12:

[0156] In Formula 10 to Formula 12, V w is the molar volume of the pore solution, m 3 / mol, ignoring the effect of ions on the molar volume of the solution, the molar volume of water is 18.02×10 -6 m 3 / mol; R is the ideal gas constant, which is 8.314 J / (mol·K); T is the experimental temperature, K, which is 293.15 K at 20°C; RH is the relative humidity corresponding to the meniscus formed in the capillary pores, %; cosθ is the experimentally measured contact angle of the substrate surface, which is 120°;

[0157] Part 6: According to Formula 13, R 20℃ The relative change estimates E, and K is determined by equation 4. The calculation process is:

[0158] Formula 13:

[0159] In Formula 13, R 20℃,0 is the initial resistance value; R 20℃,t is the estimated resistance value; G and κ are regression constants;

[0160] Part 7: According to Formula 2, the elastic deformation ε in the total deformation e Part of it is expressed by formula 14:

[0161] Formula 14:

[0162]

[0163] Part 8: Estimating τ using the mutation points of the RH and R curves k ;

[0164] Part 9: Estimation of the hydration ratio using the relative change of R according to Formula 15 The calculation process is:

[0165] Formula 15:

[0166] In formula 15, m and n are regression constants;

[0167] Part 10: According to Formula 16, the liquid-solid ratio ω is estimated using the relative change of R. The calculation process is:

[0168] Formula 16:

[0169] In formula 16, C and u are regression constants;

[0170] Part 11: According to Formula 3, the elastic deformation ε in the total deformation creep Part of it is expressed by formula seventeen:

[0171] Formula 17:

[0172]

[0173] Part 12: According to Formula 14 and Formula 17, combined with the measured data of early deformation of cement-based materials and the shrinkage deformation model, and then according to Formula 14, calculate the increment Δ of elastic deformation at intervals of 10min, 30min, 60min, and 120min elas , respectively, using the multivariate nonlinear regression method to estimate η, a, G, κ, m, n, C, and u;

[0174] Part 13: Test the residual distribution characteristics, residual extreme values, and residual distribution characteristics of the regression model with different time intervals, systematically analyze the impact of time interval on the reliability and accuracy of regression analysis, and determine the optimal time interval;

[0175] Part 14: Combination Figures 10 to 13 As shown in the figure, according to Formula 14 and Formula 17, the elastic deformation ε of cement-based materials is established. e and creep during autogenous shrinkage creep The change process over time can predict the risk of early shrinkage and cracking of cement-based materials, and provide analytical data support for further analysis of the early performance evolution of cement-based materials.

[0176] The multi-parameter integrated testing platform for cement-based materials in the present testing method comprises a square mold box 1, a data acquisition instrument 2 and at least one debugging column 3, the square mold box 1 and the at least one debugging column 3 are respectively connected to the data acquisition instrument 2, at least one debugging column 3 and the square mold box 1 are both filled with a testing slurry 20, wherein the testing slurry 20 filled and injected into the square mold box 1 is a large-volume testing slurry, and the testing slurry 20 filled and injected into the debugging column 3 is a part of the large-volume testing slurry, forming a local small-volume testing slurry.

[0177] In the present embodiment, the top of the square mold box 1 is an open end, and the square mold box 1 is filled with a test slurry 20. The specific structure of the square mold box 1 is that it consists of five square templates 12, four of the five square templates 12 are vertically enclosed in sequence to form a square frame, and the remaining square template 12 of the five square templates 12 serves as the bottom of the square frame, and the four edges of the square template 12 are respectively connected to the edges of the bottom of the square frame, and the bottom of the square frame is fixedly connected to the square template 12 as a whole to form a mold structure with an open top, and a large square filling cavity that matches the test slurry 20 is formed between the bottom of the square frame and the inner wall of the square template 12.

[0178] The test slurry 20 in this embodiment is specifically a cement-based material slurry.

[0179] In this embodiment, the square frame is processed with a through hole 13 along its thickness direction, which is used to bury relevant sensors inside the test slurry 20. Specifically, the test slurry 20 is specifically a cement-based material layer. The through hole 13 of the square mold box 1 provides an entry and exit position for the isolation tube body 5 to pass through. The through hole 13 is a circular hole, and its inner diameter is less than one-fifth of the length of the square template 12. The isolation tube body 5 is a hollow tube body, and its outer diameter is smaller than the inner diameter of the through hole 13. The difference between the two is less than or equal to one-tenth of the through hole 13, thereby ensuring a tightly coaxial penetration process. The isolation tube body 5 is arranged in the test slurry 20, and an electrode 6 is buried in the test slurry 20. One end of the isolation tube body 5 passes through the through hole 4 and is connected to the data acquisition instrument 2.

[0180] In this embodiment, a temperature and humidity sensor 7 is disposed in the isolation tube body 5. The temperature and humidity sensor 7 is an existing sensor, and its working principle is the same as that of an existing temperature and humidity sensor.

[0181] In this embodiment, the other end of the isolation tube body 5 is provided with a breathable membrane 8. The isolation tube body 5 is a PVC hose.

[0182] In this embodiment, the square template 12 is processed with four insertion holes 14 along its thickness direction, and the four insertion holes 14 are arranged in a square matrix, which are evenly distributed on the square template 12 to provide insertion positions for the electrodes 6. The electrodes 6 are existing strip electrodes, and their working principle is the same as that of existing strip electrodes.

[0183] In this embodiment, the debugging column 3 includes a accommodating tube 3-1, a vertical support member 3-2, a base 3-3, a top block 3-4, a metal disc 3-5, a displacement sensor 3-7 and a lifting debugging member 3-8. The accommodating tube 3-1 is vertically arranged on the base 3-3. The inner cavity of the accommodating tube 3-1 is a filling cavity 3-6 for matching the test slurry 20. The metal disc 3-5 is arranged in the filling cavity 3-6. The metal disc 3-5 is tightly attached to the upper surface of the test slurry 20. The vertical support member 3-2 is vertically arranged on the base 3-3. A top block 3-4 is provided at the upper end of the support member 3-2, and the top block 3-4 is directly above the metal disc 3-5. A displacement sensor 3-7 facing the metal disc 3-5 is provided on the bottom surface of the top block 3-4. A lifting and adjusting member 3-8 is provided on the vertical support member 3-2, and the lifting and adjusting member 3-8 is connected to the displacement sensor 3-7. Driven by the lifting and adjusting member 3-8, the displacement sensor 3-7 makes a reciprocating motion toward or away from the metal disc 3-5 along the height direction of the vertical support member 3-2.

[0184] Among them, the lifting and adjusting member 3-8 is an existing lifting and adjusting member, which specifically includes a gear, a rack and a knob. The top of the vertical support member 3-2 is processed with a vertical groove body, and a rack is arranged in the vertical groove body. One side of the rack is slidably matched with the inner wall of the groove of the vertical groove body, and the other side of the rack is meshed with a gear. The gear is matched with a knob, and the knob is arranged on the outer wall of the vertical support member 3-2. The top of the rack is fixedly connected with a top block 3-4. The working principle of the lifting and adjusting member 3-8 is as follows:

[0185] Turn the knob clockwise, and the rotation of the knob drives the gear to rotate synchronously, and the rotation of the gear drives the rack to move vertically upward. When the rack moves vertically upward, it drives the top block 3-4 to rise synchronously, thereby increasing the distance between the probe of the displacement sensor 3-7 and the top of the containing tube 3-1. Similarly, turn the knob counterclockwise, and the rotation of the knob drives the gear to rotate synchronously, and the rotation of the gear drives the rack to move vertically downward. When the rack moves vertically downward, it drives the top block 3-4 to fall synchronously, thereby decreasing the distance between the probe of the displacement sensor 3-7 and the top of the containing tube 3-1.

[0186] The structures and connection relationships not mentioned in this embodiment are the same as those in the specific embodiments one, two, three, four, five, six or seven.

Claims

1. A testing method implemented by a multi-parameter integrated testing platform for cement-based materials, characterized in that: A cement-based material multi-parameter integrated testing platform comprises a square mold box (1), a data acquisition instrument (2) and at least one debugging column (3), wherein the square mold box (1) and the at least one debugging column (3) are respectively connected to the data acquisition instrument (2), and the at least one debugging column (3) and the square mold box (1) are both filled with a testing slurry (20); The debugging column (3) comprises a containing tube (3-1), a vertical support member (3-2), a base (3-3), a top block (3-4), a metal disc (3-5), a displacement sensor (3-7) and a lifting debugging member (3-8); the containing tube (3-1) is vertically arranged on the base (3-3); the inner cavity of the containing tube (3-1) is a filling cavity (3-6) for matching the test slurry (20); the metal disc (3-5) is arranged in the filling cavity (3-6); the metal disc (3-5) is closely attached to the upper surface of the test slurry (20); the vertical support member (3-2) is vertically arranged on the base (3-3); the vertical support member (3-4) is vertically arranged on the base (3-3); the metal disc (3-5 ...8); the metal disc (3- A top block (3-4) is arranged at the upper end of the support member (3-2), the top block (3-4) is located directly above the metal disc (3-5), a displacement sensor (3-7) facing the metal disc (3-5) is arranged on the bottom surface of the top block (3-4), a lifting and adjusting member (3-8) is arranged on the vertical support member (3-2), the lifting and adjusting member (3-8) is connected to the displacement sensor (3-7), and the displacement sensor (3-7) is driven by the lifting and adjusting member (3-8) to make a reciprocating motion towards or away from the metal disc (3-5) along the height direction of the vertical support member (3-2); The top of the square mold box (1) is an open end. The test slurry (20) filled in the square mold box (1) is a cement-based material layer. The side wall of the square mold box (1) is processed with a through hole (13). An isolation tube body (5) is arranged in the square mold box (1). The isolation tube body (5) is arranged in the test slurry (20). An electrode (6) is buried in the test slurry (20). One end of the isolation tube body (5) passes through the through hole (13) and is connected to a data acquisition instrument (2). The data acquisition instrument (2) is arranged on the outer wall of the square mold box (1). A data display screen (9) is arranged on the top surface of the data acquisition instrument (2). An SD card (11) is arranged in the data acquisition instrument (2). A temperature and humidity sensor (7) is arranged in the isolation tube body (5); A breathable membrane (8) is provided at the other end of the isolation tube body (5), and the isolation tube body (5) is a PVC hose; A plastic film (10) is arranged in the debugging column (3), and the plastic film (10) is arranged between the debugging column (3) and the test slurry (20). The bottom surface of the plastic film (10) is closely attached to the upper surface of the test slurry (20), and the bottom surface of the metal disc (3-5) is closely attached to the top surface of the plastic film (10); The multi-parameter integrated testing method for cement-based materials includes the following steps: Mold preparation stage: placing the electrode (6) and the temperature and humidity sensor (7) inside the square mold box (1) in advance; Casting stage: the mixed cement-based material is cast in two layers in a square mold box (1), and after the square mold box (1) is placed on a vibration table, the first cement-based material layer is molded into the square mold box (1), and the cement-based material is compacted to a uniform and dense state by tamping up and down with a tamping rod and vibrating on the vibration table, and then the remaining slurry is cast to form a second cement-based material layer. Similarly, after a double layer of cement-based material layers is cast in the containing tube (3-1), a plastic film (10) and a metal disc (3-5) are placed in sequence on the upper surface of the test slurry (20); Data collection stage: connect the various sensor interfaces derived from the square mold box (1) to the data acquisition device (2), and then connect the power supply of the device to ensure that the vertical distance between the displacement sensor (3-7) and the metal disc (3-5) in the debugging column (3) is continuously less than 150 μm during the data collection process; Data acquisition and storage: the test time data, resistance data, relative humidity data of the test slurry (20) and self-shrinkage data of the test slurry (20) collected by the data acquisition device (2) are stored in an SD card (11) in the data acquisition device (2). After reaching a predetermined collection period, the collected data are centrally exported from the SD card (11) for subsequent analysis and calculation processes; The subsequent analysis and calculation process after the collected data is centrally exported from the SD card (11) is as follows: According to the early shrinkage deformation theory of cement-based materials, the total deformation ε is obtained by formula 1, which is composed of the elastic deformation ε e and creep ε creep Composition relationship, where ε e It can be obtained by formula 2, combining the saturation degree S and capillary pressure σ cap , the bulk modulus K of the matrix is ​​quantitatively described, and ε creep Then the increment of elastic deformation Δ can be used from formula 3 elas , zero point of autogenous contraction τ k , the ratio of hydration degree The liquid-to-solid ratio ω and the relaxation factor n yield: Formula 1: ε = ε e + ε creep ; Formula 2: Formula 3: In formula 2, K s is the solid phase bulk modulus, in GPa. Since the main component of cement-based materials is silicate phase, the bulk modulus of solid silicate is taken as 44 GPa. According to Formula 4, the function K, that is, the bulk modulus K of the matrix, is obtained. The bulk modulus K of the matrix is ​​a function of the material elastic modulus E and Poisson's ratio v, where the material elastic modulus E is in GPa. The Poisson's ratio of cement-based materials is usually taken as 0.2; in Formula 3, n is usually taken as a constant: 0.30; Formula 4: According to the real-time monitoring of cement-based material resistance R, internal relative humidity RH, temperature Temp data, S and σ in formula 2 are estimated. cap , K and τ in formula 3 k , ω, and then use Formula 2 to determine the increment of elastic deformation at different time intervals Δ elas , combined with the early deformation monitoring value of cement materials and formula 1, the inverse analysis of the elastic deformation ε of cement-based materials is established e and creep during autogenous shrinkage creep The algorithm of development law includes the following parts: Part 1: According to Formula 1, Formula 2 and Formula 3, the parameters that need to be determined in initializing the early shrinkage model parameters of cement materials are determined: S, σ cap , K and τ in formula 3 k , ω; Part 2: Read the real-time monitoring data of the resistance R and temperature Temp of cement-based materials, and use formula 5 to normalize the resistance data to 20°C; Formula 5: R 20℃ =R temp [1+α(Temp-20)]; In Formula 5, R 20℃ The resistance of the material at 20°C, unit: ohm; R temp is the resistance of the material at Temp℃, unit: ohm; α is the temperature regression coefficient; Part 3: Read the real-time monitoring data of relative humidity RH and temperature Temp of cement-based materials. According to the following steps, the internal RH data of the monitored cement-based materials is normalized to 20°C to remove the influence of temperature on the relative humidity test results. Specifically, it includes three steps: Step 1: Calculate the saturated vapor pressure of water vapor at the measured temperature based on the measured temperature and formula 6: Formula 6: In formula 6, P vsT is the saturated vapor pressure of water vapor at the measured temperature, in Pa; e is a natural constant, 2.718; T is the measured Kelvin temperature, T = t + 273.15, K, t is degrees Celsius, ℃; A, B, C, D, E, F are constants, A is -5800.2206, B is 1.3914993, C is -0.048640239, D is 0.41764768×10 -4 , E is -0.14452093×10 -7 , F is 6.5459673; Step 2: Based on the measured relative humidity data, calculate the water vapor pressure in the microenvironment of cement-based materials according to Formula 7: Formula 7: p vT =p vsT ×RH T ; In formula 7, p vT The unit is Pa; RH is the water vapor pressure in the measured microenvironment. T Relative humidity in the measured microenvironment, unit: %; Step 3: Convert the relative humidity of the cement-based material microenvironment to the relative humidity at 20°C: Formula 8: In formula 8, p v20℃ is the saturated vapor pressure of water vapor at 20°C, 2.3388×10 3 Pa; RH 20℃ is the relative humidity of the microenvironment at 20°C, in %; Part 4: Establishing RH using Formula 9 20℃ Relationship with S: Formula 9: S = ηlog(RH 20℃ )+a; In formula 9, η and a are regression constants; Part 5: Using Formula 10, Formula 11 and Formula 12, the internal relative humidity RH 20℃ Estimation of σ cap ; Formula 10: Formula 11: Formula Twelve: In Formula 10 to Formula 12, V w is the molar volume of the pore solution, m 3 / mol, ignoring the effect of ions on the molar volume of the solution, the molar volume of water is 18.02×10 -6 m 3 / mol; R is the ideal gas constant, which is 8.314 J / (mol·K); T is the experimental temperature, K, which is 293.15 K at 20°C; RH is the relative humidity corresponding to the meniscus formed in the capillary pores, %; cosθ is the experimentally measured contact angle of the substrate surface, which is 120°; Part 6: According to Formula 13, R 20℃ The relative change estimates E, and K is determined by formula 4. The calculation process is: Formula 13: In Formula 13, R 20℃,0 is the initial resistance value; R 20℃,t is the estimated resistance value; G and κ are regression constants; Part 7: According to Formula 2, the elastic deformation ε in the total deformation e Part of it is expressed by formula 14: Formula 14: Part 8: Estimating τ using the mutation points of the RH and R curves k ; Part 9: Estimation of the hydration ratio using the relative change of R according to Formula 15 The calculation process is: Formula 15: In formula 15, m and n are regression constants; Part 10: According to Formula 16, the liquid-solid ratio ω is estimated using the relative change of R. The calculation process is: Formula 16: In formula 16, C and u are regression constants; Part 11: According to Formula 3, the elastic deformation ε in the total deformation creep Part of it is expressed by formula seventeen: Formula 17: Part 12: According to Formula 14 and Formula 17, combined with the measured data of early deformation of cement-based materials and the shrinkage deformation model, and then according to Formula 14, calculate the increment Δ of elastic deformation at intervals of 10min, 30min, 60min, and 120min elas , respectively, using the multivariate nonlinear regression method to estimate η, a, G, κ, m, n, C, and u; Part 13: Test the residual extreme values ​​and residual distribution characteristics of the regression model with different time intervals, systematically analyze the influence of time interval on the reliability and accuracy of regression analysis, and determine the optimal time interval; Part 14: Based on Formula 14 and Formula 17, establish the elastic deformation ε of cement-based materials e and creep during autogenous shrinkage creep The change process over time can predict the risk of early shrinkage and cracking of cement-based materials, and provide analytical data support for further analysis of the early performance evolution of cement-based materials.

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