Measuring instrument and measuring method capable of synchronously detecting deformation and weight of cement-based material in high-temperature environment

Abstract

The invention relates to a measuring instrument and a measuring method capable of synchronously detecting deformation and weight of a cement-based material in a high-temperature environment, and the measuring instrument comprises a high-temperature environment box, a plurality of sample tables are arranged in the high-temperature environment box along the length direction, and tested pieces are placed on the sample tables; transparent observation windows are arranged on the two side walls of the long edge of the high-temperature environment box. The length measuring system is arranged outside the high-temperature environment box and is used for measuring the displacement deformation of the tested piece; and the weight measuring system is arranged below the high-temperature environment box and is used for measuring the weight variation of the tested piece. The invention can solve the problem that the prior art and device cannot meet the requirements of measuring sample deformation and weight change at high temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of monitoring changes of cement-based materials in a high-temperature environment, and in particular to a measuring instrument and a measuring method capable of synchronously detecting the deformation and weight of cement-based materials in a high-temperature environment. Background Art

[0002] In the research of cement-based materials, the drying shrinkage of cement-based materials (such as concrete) due to internal moisture loss has been widely studied. The crack problem caused by the drying shrinkage of cement-based materials has an important impact on the safety and durability of concrete structures.

[0003] As a primary building material, concrete is widely used in various types of construction. However, due to their specific uses, certain concrete structures are often affected by high temperatures. In high-temperature environments, the concrete loses moisture rapidly, accelerating the rate of moisture loss and causing shrinkage. Therefore, measuring the shrinkage and weight change of cementitious materials in high-temperature environments can help analyze their drying shrinkage characteristics under high-temperature conditions.

[0004] However, existing measurement methods and devices are mainly aimed at the drying shrinkage of cement-based materials under non-high temperature conditions, and cannot measure the deformation of cement-based materials under high temperature environments; there are also some measurement methods and devices that can measure the deformation characteristics of cement-based materials under high temperature environments, but cannot simultaneously measure the weight change of the measured sample.

[0005] Therefore, there is an urgent need for a measurement method and device that can simultaneously measure the shrinkage deformation and weight change of cement-based materials in a high-temperature environment, so as to improve the understanding of the drying shrinkage characteristics of concrete in a high-temperature environment. Summary of the Invention

[0006] In response to the above problems, the purpose of the present invention is to provide a measuring instrument and measuring method that can simultaneously detect the deformation and weight of cement-based materials in a high-temperature environment, so as to solve the problem that existing technologies and devices cannot meet the requirements of measuring sample deformation and weight changes under high temperatures.

[0007] To achieve the above object, the present invention adopts the following technical solutions: The measuring instrument for simultaneously detecting the deformation and weight of cement-based materials in a high-temperature environment according to the present invention comprises: A high-temperature environmental chamber, wherein a plurality of sample stages are provided along the length of the high-temperature environmental chamber, and a test piece is placed on the sample stage; transparent observation windows are provided on both side walls of the long side of the high-temperature environmental chamber; The length measurement system is set outside the high-temperature environmental chamber and is used to measure the displacement and deformation of the test piece; The weight measurement system is set below the high temperature environment box and is used to measure the weight change of the test piece.

[0008] The measuring instrument, preferably, the high-temperature environment box includes a box body, a top cover and a heating ceramic plate; the top cover is arranged on the top of the box body; several heating ceramic plates are fixed to the bottom of the box body through a fixing frame, which is used to heat the box body; a heating ceramic plate is arranged on both sides of each sample stage.

[0009] In the measuring instrument, preferably, the box includes a shell having an inner wall and an outer wall; and a heat-insulating layer is provided in the shell.

[0010] The measuring instrument preferably comprises a length measurement system comprising a multi-axis displacement platform assembly and a laser displacement sensor; two groups of the multi-axis displacement platform assemblies are arranged on the front and rear sides of the high-temperature environment box, and each group of the multi-axis displacement platform assemblies comprises a plurality of multi-axis displacement platforms; a laser displacement sensor is provided on each multi-axis displacement platform, the position of the laser displacement sensor being opposite to the transparent observation window, and the laser displacement sensor corresponds one-to-one to the test piece on the sample stage.

[0011] The measuring instrument preferably further includes a base and a bracket, wherein the base is arranged below the high-temperature environmental box; the bracket is connected to the base and is used to support the high-temperature environmental box and the multi-axis displacement platform.

[0012] The measuring instrument, preferably, the weight measuring system includes a support column and a precision balance; several precision balances are arranged on the base, and each precision balance is connected to the sample table after passing through the through hole at the bottom of the high-temperature environment box via a support column; the diameter of the through hole at the bottom of the high-temperature environment box is larger than the diameter of the support column so that the two do not form contact.

[0013] In the measuring instrument, preferably, the support column is made of zirconia; and the sample stage is made of aluminum alloy.

[0014] For the measuring instrument, preferably, the distance between the precision balance and the bottom of the high-temperature environmental box is greater than 50 mm; and a gap is left between the bottom of the sample stage and the bottom of the high-temperature environmental box.

[0015] The measuring instrument preferably further includes: a temperature measuring component for measuring the temperature inside the high-temperature environment box; a computer connected to the temperature measuring component, precision balance, and laser displacement sensor via a data line or signal connection, the computer being provided with a temperature control system and a data processing system, the temperature control system being used to control the temperature inside the high-temperature environment box according to the real-time measured temperature inside the high-temperature environment box and a pre-set heating mechanism; the data processing system being used to obtain and store in real time the temperature inside the high-temperature box measured by the temperature measuring component, the weight value measured by the precision balance, and the change value of the sample length measured by the laser displacement sensor, so as to realize the integration of control, data acquisition, and processing.

[0016] The present invention also provides a measuring method for a measuring instrument capable of simultaneously detecting deformation and weight of cement-based materials in a high-temperature environment, comprising the following steps: After turning on the measuring instrument, open the top cover of the high-temperature environmental chamber and place the test piece on the sample table, with the two measured end faces of the test piece in the length direction facing the transparent observation windows on both sides, and the measured end faces of the test piece and the transparent observation windows remain parallel; obtain the initial weight of the test piece using a precision balance and transmit the data to the data processing system; at the same time, manually enter the initial length of the test piece into the data processing system; Close the top cover and wait until the laser displacement sensor reading stabilizes. The current positions of the two end faces of the tested object are the initial positions, and the laser displacement sensor is “cleared”. After setting the temperature, heating rate, and data acquisition frequency, heating begins. The temperature measuring component inside the high-temperature environmental chamber measures the temperature inside the chamber in real time. The temperature control system controls the temperature inside the chamber based on the measured temperature inside the chamber and the set heating mechanism. After heating begins, the precision balance continuously measures the weight of the test piece, and the laser displacement sensors on both sides continuously measure the displacement changes of the two end faces of the test piece in the length direction. For the measurement of the laser displacement sensor, when the measured end face moves away from the laser displacement sensor, the laser displacement sensor reads a negative number, indicating that the test piece is in a contracted state, and the measured data is the length contraction value; when the measured end face moves toward the laser displacement sensor, the laser displacement sensor reads a positive number, indicating that the test piece is in an expanded state, and the measured data is the length expansion value; The computer obtains the temperature inside the box measured by the temperature measuring component, the length change of the test piece measured by the laser displacement sensor, and the weight of the test piece measured by the precision balance in real time according to the preset collection frequency.

[0017] The present invention has the following advantages due to the adoption of the above technical solution: (1) The present invention can simultaneously measure the length change and weight change of a sample in a high temperature environment, with a temperature range from room temperature to 300°C; it is simple to operate and can perform continuous measurement for a long time; (2) The type and size of the test sample of the present invention can be flexibly selected: the present invention is mainly for cement-based material samples (such as concrete, mortar, cement paste, etc.), but other material samples that meet the size requirements and will not cause damage to the device can be used; the suitable sample size is a prismatic sample with a width of 20-80mm, a length of 120-160mm, and a height of 30-100mm; (3) The relevant parameters in the temperature control system of the present invention are flexible and adjustable with high precision: the test temperature can be set from room temperature to 300°C, the heating rate can be set according to demand, and the temperature control accuracy is ±3°C; (4) The laser displacement sensor of the present invention is mounted outside the high-temperature environment box and is placed separately on brackets on both sides of the box body, so that the laser sensor is protected from the influence of high temperature, ensuring long-term normal operation and ensuring measurement accuracy; (5) The laser sensor probe of the present invention is directly facing the transparent observation window on the side of the box. The laser sensor can directly measure the changes of the sample in the box through the window, so that the measurement is not affected by high temperature; (6) The present invention transmits the weight of the sample under test in the high temperature environment to the precision weighing system (precision balance) below the high temperature environment box through the weight transmission system (support column), thereby realizing the weight monitoring of the sample; (7) The present invention heats the interior of the environmental chamber and the sample by means of ceramic heating plates installed on both sides of each sample stage, and controls the internal temperature of the environmental chamber by means of temperature measuring components and a temperature control system in the chamber; the heating device can precisely control the temperature and avoid temperature rise lag and temperature fluctuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. Throughout the drawings, the same reference numerals are used to denote the same components. In the drawings: Figure 1 is a front cross-sectional view of the measuring instrument of the present invention; Figure 2 It is a side sectional view of the measuring instrument described in the present invention.

[0019] The reference numerals in the figures are as follows: 1-High temperature environmental chamber; 101-Box; 1011-Shell; 1012-Insulation layer; 102-Top cover; 103-Heating ceramic plate; 2-Sample stage; 3-Test piece; 4-Transparent observation window; 5-Length measurement system; 501-Multi-axis displacement platform assembly; 502-Laser displacement sensor; 6-Weight measurement system; 601-Support column; 602-Precision balance; 7-Base; 8-Bracket; 9-Thermocouple; 10-Fixed bracket; 11-Computer. DETAILED DESCRIPTION

[0020] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0021] The present invention provides a measuring instrument and a measuring method capable of synchronously detecting the deformation and weight of cement-based materials in a high-temperature environment. The length measurement system and the weight measurement system therein are used to measure the deformation and weight change of a specimen under high temperature. Simultaneously, a laser displacement sensor is placed outside a high-temperature environment box, and the shape change of the specimen in the high-temperature heating box is directly measured through a transparent observation window. This avoids the drawback that the displacement sensor is susceptible to damage due to high temperature, and eliminates the influence of deformation of the displacement conduction system due to high temperature. Compensation and correction of the measurement data based on the deformation of the displacement conduction system under high temperature are no longer required. Furthermore, because the laser displacement sensor adopts a non-contact measurement method, it will not affect the measurement of the specimen weight.

[0022] like Figure 1 and Figure 2 As shown, the present invention provides a measuring instrument that can simultaneously detect the deformation and weight of cement-based materials in a high-temperature environment, including: a high-temperature environmental chamber 1, in which a plurality of sample tables 2 are arranged along the length direction, and a test piece 3 is placed on the sample table 2; transparent observation windows 4 are provided on both side walls of the long side of the high-temperature environmental chamber 1; a length measurement system 5 is arranged outside the high-temperature environmental chamber 1, and is used to measure the displacement deformation of the test piece 3; a weight measurement system 6 is arranged below the high-temperature environmental chamber 1, and is used to measure the weight change of the test piece 3.

[0023] In the above embodiment, the high-temperature environmental chamber 1 preferably includes a chamber 101, a top cover 102, and heating ceramic plates 103. The top cover 102 is located on the top of the chamber 101. Several heating ceramic plates 103 are fixed to the bottom of the chamber 101 via a fixing frame 10 to heat the chamber 101. A heating ceramic plate 103 is provided on both sides of each sample stage 2. Thus, the heating ceramic plates 103 can heat the chamber 101 to reach the set temperature.

[0024] It should be noted that the heating ceramic plate 103 is set at a distance from the bottom of the box, and its height is close to the height of the sample stage.

[0025] In the above embodiment, preferably, the box body 101 includes a shell 1011 having an inner wall and an outer wall; an insulation layer 1012 is provided in the shell 1011, wherein the insulation layer 1012 is made of an insulation material (such as a ceramic fiber material); thereby, the box body 101 can have an insulation function to avoid heat loss.

[0026] In the above embodiment, the length measurement system 5 preferably includes a multi-axis displacement platform assembly 501 and a laser displacement sensor 502 . Two sets of multi-axis displacement platform assemblies 501 are disposed on the front and rear sides of the high-temperature environmental chamber 1 , with each set of multi-axis displacement platform assemblies 501 comprising a plurality of multi-axis displacement platforms. Each multi-axis displacement platform is provided with a laser displacement sensor 502 . The multi-axis displacement platform allows for flexible adjustment of the position of the laser displacement sensor, enabling full-scale movement of the laser displacement sensor in the front-back, left-right, and up-down directions. The laser displacement sensor 502 is positioned opposite the transparent observation window 4 , and each laser displacement sensor 502 corresponds one-to-one with the test piece 3 on the sample stage 2 . Thus, the laser displacement sensor 502 can measure the displacement and deformation of the corresponding test piece 3 through the transparent observation window 4 .

[0027] In the above embodiment, preferably, the present invention further includes a base 7 and a bracket 8. The base 7 is arranged below the high temperature environment box 1. The bracket 8 is connected to the base 7 to support the high temperature environment box 1 and the multi-axis displacement platform.

[0028] In the above embodiment, preferably, the weight measurement system 6 includes a support column 601 and a precision balance 602; several precision balances 602 are arranged on the base 7, and each precision balance 602 is connected to the sample table 2 after passing through the through hole at the bottom of the high-temperature environment box 1 through the support column 601; thus, the weight change of the test piece 3 can be measured by the precision balance 602.

[0029] The diameter of the through hole at the bottom of the high temperature environment box 1 is larger than the diameter of the support column 601 so that the two do not form contact, thereby minimizing heat loss.

[0030] In the above embodiment, preferably, the support column 601 is made of zirconium oxide. Since zirconium oxide is not easily deformed and has poor thermal conductivity, it can prevent the support column 601 from transferring heat to the precision balance 602. The material of the sample stage 2 is aluminum alloy; thus, the surface of the sample stage can be smooth, which is conducive to the deformation of the test piece.

[0031] In the above embodiment, preferably, the distance between the precision balance 602 and the bottom of the high temperature environment box 1 is greater than 50 mm; thereby, the precision balance can be prevented from being affected by high temperature.

[0032] There is a gap between the bottom of the sample stage 2 and the bottom of the high-temperature environmental chamber 1; thereby, during the test, the sample stage is prevented from contacting the bottom plate of the environmental chamber, which would affect the weight measurement result.

[0033] In the above embodiment, preferably, the present invention further comprises: a temperature measuring component for measuring the temperature in the high temperature environment box 1 , the temperature measuring component may be a temperature sensor or a thermocouple 9 , in this embodiment, a thermocouple 9 ; The computer 11 is connected to the temperature measuring component, the precision balance 602, and the laser displacement sensor 502 via a data line or a signal connection, and the computer is provided with a temperature control system and a data processing system; The temperature control system is used to control the temperature inside the high-temperature environmental box 1 according to the real-time measured temperature inside the high-temperature environmental box 1 and the pre-set heating mechanism; the data processing system obtains and stores in real time the temperature inside the high-temperature box measured by the temperature measuring component, the weight value measured by the precision balance 602, and the sample length change value measured by the laser displacement sensor 502.

[0034] It should be noted that the temperature control system in the present invention can adopt any temperature control system in the prior art, and the data processing system can adopt any data processing system in the prior art, and their specific structures will not be described in detail here.

[0035] The present invention also provides a measuring method for a measuring instrument capable of simultaneously detecting deformation and weight of cement-based materials in a high-temperature environment, comprising the following steps: Step 1: After turning on the measuring instrument, open the top cover 102 of the high-temperature environment 1 and place the test piece 3 on the sample stage 2, with the two measured end faces of the test piece 3 in the longitudinal direction facing the transparent observation windows 4 on both sides, and the measured end faces of the test piece 3 remaining parallel to the transparent observation windows 4. Obtain the initial weight of the test piece 3 using the precision balance 602 and transmit the data to the data processing system. Simultaneously, manually input the initial length of the test piece 3 into the data processing system. Step 2: Close the top cover 102, wait until the reading of the laser displacement sensor 502 is stable, and the positions of the two end surfaces of the current test piece are the initial positions, and perform a "zero reset" process on the laser displacement sensor 502; Step 3: After setting the temperature, heating rate, and data acquisition frequency, heating begins. The temperature measuring component in the box 101 of the high-temperature environmental chamber 1 measures the temperature inside the box in real time. The temperature control system controls the temperature inside the box based on the measured temperature inside the box 101 and the set heating mechanism. Step 4: After heating begins, the precision balance 602 continuously measures the weight of the test piece 3, and the laser displacement sensors 502 on both sides continuously measure the displacement changes of the two end faces of the test piece in the length direction. For the measurement of the laser displacement sensor 502, when the measured end face moves in a direction away from the laser displacement sensor 502, the laser displacement sensor 502 reads a negative number, indicating that the test piece is in a contracted state, and the measured data is the length contraction value; when the measured end face moves in a direction toward the laser displacement sensor 502, the laser displacement sensor 502 reads a positive number, indicating that the test piece 3 is in an expanded state, and the measured data is the length expansion value; Step 5: The computer 11 obtains in real time the temperature inside the box measured by the temperature measuring component, the length change of the test piece measured by the laser displacement sensor 502 and the weight of the test piece measured by the precision balance 602 according to the preset acquisition frequency.

[0036] In addition, it should be noted that the present invention is mainly aimed at cement-based material samples (such as concrete, mortar, cement paste, etc.), but other material samples that meet the size requirements and will not cause damage to the device can be used; suitable sample sizes are prismatic samples with a width of 20-80mm, a length of 120-160mm, and a height of 30-100mm; The data processing system can calculate the weight change and length change of the specimen. The specific calculation formula is as follows: Specimen weight change:

[0037] Specimen length change:

[0038] Where M0 is the initial weight; M i is the weight of the specimen after being heated at the set temperature for i time; L1 and L2 are the displacements measured by the laser displacement sensors on both sides of the test piece.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A measuring instrument capable of simultaneously detecting the deformation and weight of cement-based materials in a high-temperature environment, characterized in that: include: A high-temperature environmental chamber, wherein a plurality of sample stages are provided along the length of the high-temperature environmental chamber, and a test piece is placed on the sample stage; transparent observation windows are provided on both side walls of the long side of the high-temperature environmental chamber; The length measurement system is set outside the high-temperature environmental chamber and is used to measure the displacement and deformation of the test piece; The weight measurement system is set below the high temperature environment box and is used to measure the weight change of the test piece.

2. The measuring instrument according to claim 1, characterized in that The high temperature environment box includes a box body, a top cover and a heating ceramic plate; The top cover is arranged on the top of the box body; A plurality of heating ceramic plates are fixedly arranged at the bottom of the box body through a fixing frame, and are used for heating the box body; a heating ceramic plate is respectively arranged on both sides of each sample stage.

3. The measuring instrument according to claim 2, characterized in that The box body comprises a shell having an inner wall and an outer wall; a heat-insulating layer is arranged in the shell.

4. The measuring instrument according to claim 1, characterized in that The length measurement system includes a multi-axis displacement platform assembly and a laser displacement sensor; Two groups of multi-axis displacement platform assemblies are arranged on the front and rear sides of the high-temperature environment box, and each group of multi-axis displacement platform assemblies includes a plurality of multi-axis displacement platforms; A laser displacement sensor is provided on each of the multi-axis displacement platforms. The position of the laser displacement sensor is opposite to the transparent observation window, and the laser displacement sensor corresponds to the test piece on the sample platform one by one.

5. The measuring instrument according to claim 4, characterized in that It also includes a base and a bracket, wherein the base is arranged below the high temperature environment box; The bracket is connected to the base and is used to support the high temperature environment box and the multi-axis displacement platform.

6. The measuring instrument according to claim 5, characterized in that The weight measurement system includes a support column and a precision balance; A plurality of precision balances are arranged on the base, and each precision balance is connected to the sample stage via a support column passing through a through hole at the bottom of the high temperature environment box; The diameter of the through hole at the bottom of the high temperature environment box is larger than the diameter of the support column so that the two do not form contact.

7. The measuring instrument according to claim 6, characterized in that The support column is made of zirconium oxide; the sample stage is made of aluminum alloy.

8. The measuring instrument according to claim 6, characterized in that The distance between the precision balance and the bottom of the high temperature environment box is greater than 50 mm; A gap is left between the bottom of the sample stage and the bottom of the high-temperature environment box.

9. The measuring instrument according to claim 6, characterized in that Also includes: Temperature measuring component, used to measure the temperature inside the high temperature environment box; A computer is connected to the temperature measuring component, the precision balance, and the laser displacement sensor via a data line or a signal connection. The computer is provided with a temperature control system and a data processing system. The temperature control system is used to control the temperature inside the high-temperature environmental box according to the real-time measured temperature inside the high-temperature environmental box and a pre-set heating mechanism; the data processing system is used to obtain and store in real time the temperature inside the high-temperature box measured by the temperature measuring component, the weight value measured by the precision balance, and the length change value of the sample measured by the laser displacement sensor, so as to realize the integration of control, data acquisition and processing.

10. A measurement method based on the measuring instrument capable of simultaneously detecting deformation and weight of cement-based materials in a high-temperature environment according to any one of claims 1 to 9, characterized in that: The steps include: After turning on the measuring instrument, open the top cover of the high-temperature environmental chamber and place the test piece on the sample table, with the two measured end faces of the test piece in the length direction facing the transparent observation windows on both sides, and the measured end faces of the test piece and the transparent observation windows remain parallel; obtain the initial weight of the test piece using a precision balance and transmit the data to the data processing system; at the same time, manually enter the initial length of the test piece into the data processing system; Close the top cover and wait until the laser displacement sensor reading stabilizes. The current positions of the two end faces of the tested object are the initial positions, and the laser displacement sensor is "cleared"; After setting the temperature, heating rate, and data acquisition frequency, heating begins. The temperature measuring component inside the high-temperature environmental chamber measures the temperature inside the chamber in real time. The temperature control system controls the temperature inside the chamber based on the measured temperature inside the chamber and the set heating mechanism. After heating begins, the precision balance continuously measures the weight of the test piece, and the laser displacement sensors on both sides continuously measure the displacement changes of the two end faces of the test piece in the length direction. For the measurement of the laser displacement sensor, when the measured end face moves away from the laser displacement sensor, the laser displacement sensor reads a negative number, indicating that the test piece is in a contracted state, and the measured data is the length contraction value; when the measured end face moves toward the laser displacement sensor, the laser displacement sensor reads a positive number, indicating that the test piece is in an expanded state, and the measured data is the length expansion value; The computer obtains the temperature inside the box measured by the temperature measuring component, the length change of the test piece measured by the laser displacement sensor, and the weight of the test piece measured by the precision balance in real time according to the preset collection frequency.

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