A device and method for testing the volume stability of a building material

Abstract

The application discloses a kind of building material volume stability test device and method, belong to civil engineering material performance test field, it is by being provided with support in test table top test piece installation site, and dial gauge is set on support, the length change of the test piece to be tested installed on test piece installation site can be measured, through closed cover installed on test table top, the test piece to be tested can be in closed test cavity, and temperature and / or humidity in test cavity can be adjusted by temperature and humidity adjusting component, according to the data measured by temperature and humidity measuring component and dial gauge, the length of the test piece to be tested can be calculated with the change of the change amount of environment temperature and humidity, complete volume stability test.The building material volume stability test device of the application can measure the length change amount of building material test piece when temperature and humidity change, explore the change rule of the length of building material with environment, test device structure is simple, measurement is convenient, measurement precision is higher, and it is convenient for popularization and application.

Description

Technical Field

[0001] This invention belongs to the field of civil engineering material performance testing, specifically relating to a test device and method for the volume stability of building materials. Background Technology

[0002] The volumetric stability of building materials refers to their property of maintaining a constant volume under changing environmental conditions. When the volumetric stability of building materials differs, the patterns of volume change with environmental conditions also differ. For example, concrete, bricks, and wall panels expand when the temperature rises and contract when the humidity decreases. Different building materials are combined to form a building; these materials are interdependent and mutually constrained, preventing free volume change. If the volume change patterns of different materials are inconsistent, changes in environmental temperature and humidity may cause cracking in the materials, leading to cracking in the building. Therefore, volumetric stability testing of building materials is a crucial aspect of research on the crack resistance of buildings.

[0003] The main purpose of volumetric stability testing of building materials is to measure how building materials change with ambient temperature and humidity. In existing technology, a concrete shrinkage-expansion apparatus is a conventional instrument used to determine the length (volume) change of concrete specimens under specified temperature and humidity conditions. Additionally, there are some testing devices for measuring the linear expansion coefficient of materials. Their principle is to heat or cool the specimen while simultaneously measuring the change in its length, thereby calculating the linear expansion coefficient. However, these devices cannot measure the change in material length under simultaneous changes in temperature and humidity.

[0004] Although concrete shrinkage and expansion meters can measure the length change of specimens under certain temperature and humidity conditions, the temperature and humidity of the test environment are fixed, which cannot realistically simulate the service environment of the specimens. Therefore, they cannot detect the shrinkage and expansion of specimens under different temperature and humidity environments, resulting in poor reliability of the test results. Furthermore, multiple tests are required for specimens of the same specification to ensure accuracy, and they cannot test specimens of different sizes, leading to low testing efficiency and poor practicality. In addition, changes in temperature and humidity not only affect the length of the specimen but also the length of the measuring device itself. In this experiment, the length change of the specimen was relatively small; therefore, ignoring the change in the length of the measuring device itself could also introduce significant errors into the test results. Summary of the Invention

[0005] In response to one or more of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a test device and method for the volume stability of building materials, which can measure the length change of building material specimens when temperature and humidity change simultaneously, so as to explore the law of the length (volume) change of building materials with environmental conditions. The test device has a simple structure, is convenient to measure, has high measurement accuracy, and is easy to popularize and apply.

[0006] To achieve the above objectives, the present invention provides a testing device for the volume stability of building materials, comprising:

[0007] The test bench has at least one mounting position for mounting the test specimen, and a bracket consisting of vertical and horizontal mounting components is provided corresponding to the mounting position; and

[0008] The vertical mounting component is vertically mounted on the test bench, and the horizontal mounting component is vertically mounted on the vertical mounting component. A dial indicator is provided on the horizontal mounting component, and the measuring rod of the dial indicator is parallel to the vertical mounting component, so that the measuring head of the dial indicator can correspondingly abut against the top surface of the test piece installed in the corresponding test piece mounting position.

[0009] A closed enclosure, which can be installed on the test bench surface and form a closed test cavity with the test bench surface;

[0010] A temperature and humidity control component is provided corresponding to the test cavity and is used to adjust the temperature and / or humidity inside the test cavity;

[0011] A temperature and humidity measurement assembly, comprising a combined temperature sensor and a humidity sensor, for measuring temperature and humidity in the test environment parameters of the test specimen.

[0012] As a further improvement of the present invention, the installation height of the lateral mounting member on the vertical mounting member is adjustable.

[0013] As a further improvement of the present invention, the bracket includes a plurality of first brackets;

[0014] The first bracket can be installed on the test platform and corresponding to a single specimen mounting position.

[0015] As a further improvement of the present invention, the specimen mounting positions are multiple, and the bracket further includes at least one second bracket;

[0016] The second bracket can be installed on the test platform and correspond to multiple specimen mounting positions simultaneously.

[0017] As a further improvement of the invention, at least two of the vertical mounting members in the first brackets are made of materials with different coefficients of linear expansion.

[0018] As a further improvement of the present invention, the temperature and humidity regulating component includes a heater and a temperature control switch, wherein the temperature control switch is electrically connected to the heater and the temperature sensor respectively;

[0019] and / or

[0020] The temperature and humidity control assembly includes a humidifier and a humidity control switch, wherein the humidity control switch is electrically connected to the humidifier and the humidity sensor, respectively.

[0021] As a further improvement of the present invention, the temperature and humidity control component further includes a data acquisition recorder, which is electrically connected to the temperature sensor, humidity sensor and dial gauge respectively.

[0022] As a further improvement of the present invention, the building material volume stability testing device also includes a bottom shell with a box-shaped structure with an open top.

[0023] The test platform is installed at the opening of the bottom shell and closes the opening; the heater and / or humidifier are disposed in the bottom shell; and a through hole communicating with the bottom shell is provided on the test platform.

[0024] Another aspect of the present invention provides a method for testing the volume stability of building materials, comprising the following steps:

[0025] (1) Install the test piece on the corresponding test piece mounting position and place the probe of the dial indicator corresponding to the test piece mounting position against the top surface of the test piece;

[0026] (2) Install a sealing cover on the test bench and seal the test piece inside the test cavity; settling time t 0. The initial measurement parameters of the test specimen, i.e., the temperature reading, are measured by the temperature and humidity measuring components and the dial gauge. T 0. Humidity reading S 0 and dial gauge reading l 0;

[0027] (3) The temperature and / or humidity control components are used to adjust the temperature and / or humidity in the test cavity to the test set value; settling time t 1. The test parameters of the test specimen, namely the temperature reading, are measured using a temperature and humidity measuring component and a dial gauge. T 1. Humidity reading S 1 and dial indicator readings l 1;

[0028] (4) Calculate the change in length of the test piece using the following formula:

[0029] Δl =(T 1- T 0)· α·L -( l 1- l 0)

[0030] In the formula, Δl The change in length of the test piece; α The coefficient of linear expansion of the material of the vertically installed component; L The height of the horizontally mounted component from the test bench surface.

[0031] Another aspect of the present invention provides a method for testing the volume stability of building materials, comprising the following steps:

[0032] (1) Prepare multiple sets of test specimens. Each set of test specimens includes multiple test specimen units of the same specifications made of the same material, and the test specimens of different sets are made of different materials and of the same specifications.

[0033] (2) Install the test piece on the test bench corresponding to the first bracket and the second bracket respectively, and make the dial indicator probe on each bracket abut against the test top surface of the corresponding test piece;

[0034] Different sets of specimen units are installed at the specimen mounting positions corresponding to the second support. A 0、 B 0、 C 0 …X 0, where X is the th x Group of test pieces, x The number is an integer not less than 2; at the same time, at least one set of the same type of specimen is installed for each of the multiple first supports. Y 1. Y 2. Y 3 …Y n Among them, type Y specimens are one type of specimen mounted on the second support, and n It is an integer not less than 2; in addition, the vertical mounting components of at least two first supports corresponding to each group of specimens of the same type are made of materials with different coefficients of linear expansion;

[0035] (3) Install a closed cover on the test bench and enclose each test piece in the test cavity; settling time t 0. The initial measurement parameters of each group of test specimens are measured by the temperature and humidity measuring components and each dial indicator, namely the temperature reading. T 0. Humidity reading S 0 and dial gauge reading l 00 , l 01 , l 02…l 0n ;

[0036] (4) The temperature and / or humidity control components are used to adjust the temperature and / or humidity in the test cavity to the test set value; settling time t 1. The temperature and humidity measuring components and dial gauges are used to measure the test parameters of each group of test specimens, namely the temperature readings. T 1. Humidity reading S 1 and readings of each dial indicator l 10 , l 11 , l 12 …l 1n ;

[0037] (5) Calculate the change in length of the test piece using the following formula:

[0038] Δl n =( T 1- T 0)· α n ·L n -( l 1n - l 0n )

[0039] In the formula, Δl n For each group n The length variation of each specimen unit; α n For each group n The coefficient of linear expansion of the material of the vertical mounting components of the support corresponding to each specimen unit; L n For each group n The height of the horizontal mounting component of the support corresponding to each specimen unit from the test bench surface;

[0040] (6) According to the Laida criterion / Grubbs criterion, outliers in the length variation of the test unit in the same group of test specimens are removed, and the average length variation of the remaining test unit is taken as the final length variation of the test specimen in the group.

[0041] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0042] In summary, the beneficial effects of the above-described technical solutions conceived by this invention compared with the prior art include:

[0043] (1) The building material volume stability testing device of the present invention has a support set on the specimen mounting position on the test platform, and a dial gauge is set on the support to measure the length change of the specimen to be tested installed on the specimen mounting position. By installing a closed cover on the test platform, the specimen to be tested can be placed in a closed test cavity. Furthermore, the temperature and humidity in the test cavity can be adjusted by the temperature and humidity adjustment component. Based on the data measured by the temperature and humidity measurement component and the dial gauge, the change in the length of the specimen to be tested with the change of ambient temperature and humidity can be calculated to complete the volume stability test. The testing device has a simple structure, is convenient for measurement, and is easy to popularize and apply.

[0044] (2) The building material volume stability test device of the present invention can simultaneously test multiple test pieces of the same material and specifications by setting a first support and a second support on the test platform, thereby improving the accuracy of the test results. It can also simultaneously measure the volume change difference of different building material test pieces under the same temperature and humidity change conditions.

[0045] (3) The building material volume stability test device of the present invention is electrically connected to the temperature sensor and the heater through a temperature control switch, and electrically connected to the humidity sensor and the humidifier through a humidity control switch. It automatically controls the test cavity to reach and maintain the set temperature and humidity, and electrically connects to the temperature sensor, humidity sensor and dial gauge through a data acquisition instrument. It automatically records the readings of the temperature sensor, humidity sensor and dial gauge, which can reduce manual observation and make the test process simple and easy.

[0046] (4) The method for testing the volume stability of building materials of the present invention involves conducting a volume stability test on building materials using the aforementioned building material volume stability testing device, and following the formula... Δl =( T 1- T 0)· α·L -( l 1- l 0) Calculate the change in length of the test piece. Δl This method can eliminate the length change of the support itself caused by temperature changes, reduce test errors, and the test method is simple and easy to implement.

[0047] (5) The building material volume stability test method of the present invention, by using the above-mentioned building material volume stability test device, can obtain the length change difference of specimen units of different materials under the same environmental temperature and humidity change; by testing the specimen units of the same group through the first support, and at least two of the vertical installation components in the first support are made of materials with different coefficients of linear expansion, the influence of the coefficient of linear expansion of the vertical installation components of the support on the test results can be obtained; further, for the test results of the specimen units of the same group, data processing is performed according to the Laida criterion / Grubbs criterion, outliers are removed, and the average value of the remaining data is taken as the final vertical length change of the test specimens of the group, thereby improving the accuracy of the test results. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a front view of the building material volume stability testing device in a preferred embodiment of the present invention;

[0050] Figure 2 This is a rear view of the building material volume stability testing device in a preferred embodiment of the present invention;

[0051] Figure 3 This is a side view of the building material volume stability testing device in a preferred embodiment of the present invention;

[0052] Figure 4 This is a top view of the building material volume stability testing device in a preferred embodiment of the present invention;

[0053] Figure 5 This is a top view of the temperature and humidity regulating component in a preferred embodiment of the present invention;

[0054] Figure 6 This is a front view of the building material volume stability testing device in another preferred embodiment of the present invention.

[0055] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:

[0056] 1. Test platform; 101. Specimen mounting position; 102. Through hole; 2. Bracket; 201. Vertical mounting component; 202. Horizontal mounting component; 21. First bracket; 22. Second bracket; 3. Dial gauge; 4. Enclosed cover; 5. Test cavity; 6. Temperature and humidity control assembly; 601. Heater; 602. Temperature control switch; 603. Humidifier; 604. Humidity control switch; 605. Data acquisition and recording instrument; 7. Temperature and humidity measurement assembly; 701. Temperature sensor; 702. Humidity sensor; 8. Base shell; 10. Specimen to be tested. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0058] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0060] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0061] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0062] Example:

[0063] Please see Figures 1 - 4 The building material volume stability test device in a preferred embodiment of the present invention includes a test platform 1, a closed cover 4, a temperature and humidity control component 6, and a temperature and humidity measurement component 7.

[0064] Specifically, at least one specimen mounting position 101 for mounting the specimen 10 to be tested is formed on the test platform 1, and a bracket 2 is provided for each specimen mounting position 101. The bracket 2 is composed of a vertical mounting member 201 and a horizontal mounting member 202. The vertical mounting member 201 is vertically fixedly mounted on the test platform 1, and the horizontal mounting member 202 is vertically fixedly mounted on the vertical mounting member 201. A dial indicator 3 is provided on the horizontal mounting member 202. The measuring rod of the dial indicator 3 is parallel to the vertical mounting member 201, so that the measuring head of the dial indicator 3 can correspondingly abut against the top surface of the specimen 10 to be tested installed in the corresponding specimen mounting position 101.

[0065] In a preferred embodiment, the test platform 1 serves as the platform for conducting tests using this device. During testing, the test platform 1 is preferably parallel to a horizontal plane. The test platform 1 is preferably made of a hard, corrosion-resistant material, such as stainless steel or aluminum alloy. The shape of the test platform 1 is not limited and can be rectangular, circular, etc. The dimensions of the test platform 1 meet the space requirements for installing the test specimen, support 4, etc.

[0066] Preferably, the test specimen 10 is made of building materials, such as concrete, brick, wall panel, etc. The shape of the test specimen 10 is preferably a prism or cylinder. For example, when the test specimen 10 is a cuboid, its cross-sectional dimensions are preferably not less than 100mm × 100mm, and its height is preferably between 300 and 500mm.

[0067] Furthermore, the mounting height of the horizontal mounting component 202 on the vertical mounting component 201 is adjustable. The mounting position of the horizontal mounting component 202 on the vertical mounting component 201 can be adjusted according to the height of the test specimen 10 to accommodate specimens of different sizes.

[0068] Preferably, both ends of the horizontal mounting component 202 are vertically fixed on the vertical mounting component 201, forming a gate-shaped structure with the vertical mounting component 201. This structure is stable, firm, and not easily deformed, which can reduce test errors caused by bracket deformation.

[0069] Preferably, each transverse mounting component 202 may be equipped with multiple dial gauges 3, with the probes of the multiple dial gauges 3 respectively abutting against different positions on the top surface of the test piece 10. The length change of the test piece 10 can be obtained based on the results measured at different positions on the top surface of the test piece 10, thereby improving measurement accuracy and reducing test errors.

[0070] Furthermore, the support 2 includes a plurality of first supports 21, which can be set one-to-one with a single specimen mounting position 101 after being installed on the test bench surface 1.

[0071] In this embodiment, the test platform 1 preferably has a specimen mounting position 101, on which a first bracket 21 can be installed to test one specimen 10. Then, another first bracket 21 can be replaced to test another specimen 10. Alternatively, the test platform 1 may have multiple specimen mounting positions 101, on which multiple first brackets 21 can be installed. Each first bracket 21 corresponds to one specimen 10, allowing multiple specimens 10 to be tested simultaneously. This can be to test multiple specimens of the same material and specifications to improve the accuracy of the measurement results, or to simultaneously measure the volume change differences of specimens of different building materials under the same temperature and humidity conditions.

[0072] Furthermore, there are multiple specimen mounting positions 101, and the bracket 2 also includes at least one second bracket 22; the second bracket 22 can correspond to multiple specimen mounting positions 101 simultaneously after being installed on the test platform 1.

[0073] Preferably, the support 2 includes a first support 21 and a second support 22. Multiple first supports 21 can be installed on the test platform 1, each corresponding to a multiple specimen mounting positions 101; alternatively, only the second support 22 can be installed, corresponding to multiple specimen mounting positions 101; or both first supports 21 and second supports 22 can be installed simultaneously. Each first support 21 corresponds to one specimen mounting position 101, and each second support 22 corresponds to multiple specimen mounting positions 101. Figure 6 As shown.

[0074] In this preferred embodiment, multiple specimen mounting positions 101 can simultaneously test multiple test specimens 10. This can be to test multiple specimens of the same material and specifications to improve the accuracy of the measurement results of the device, or to simultaneously measure the volume change differences of different building material specimens under the same temperature and humidity change conditions.

[0075] Furthermore, the vertical mounting members 201 in at least two of the first supports 21 are made of materials with different coefficients of linear expansion.

[0076] Preferably, at least two of the vertical mounting members 201 of the first bracket 21 are made of materials with different coefficients of linear expansion, and the remaining vertical mounting members 201 of the first bracket 21 can be made of materials with different coefficients of linear expansion or materials with the same coefficient of linear expansion. The vertical mounting members 201 of the second bracket 22 and the first bracket 21 can be made of materials with different coefficients of linear expansion or materials with the same coefficient of linear expansion.

[0077] In this embodiment, when the coefficient of linear expansion of the vertical mounting component 201 is different, the length change of the vertical mounting component 201 during the temperature change of the test environment is different. By using vertical mounting components 201 with different coefficients of linear expansion to conduct the test, the influence of the coefficient of linear expansion of the vertical mounting component 201 on the test results can be obtained.

[0078] Furthermore, by installing the enclosure 4 on the test platform 1, a closed test cavity 5 can be formed, placing the test environment within this closed cavity to reduce interference from the external environment. If the enclosure 4 is not installed, the building material volume stability testing device is directly exposed to the natural environment, allowing for experimental research on the volume change patterns of building materials under indoor and outdoor natural conditions. Furthermore, by immersing the test specimen 10 in water until it reaches water saturation and then installing it on the device for testing, the variation of the specimen length with ambient temperature and humidity during dehydration under natural conditions can be obtained.

[0079] Preferably, the enclosure 4 can be made of a transparent material, such as plexiglass or glass, so that the experimental phenomena inside the test cavity 5 can be observed during the test.

[0080] Furthermore, the temperature and humidity in the test environment parameters of the test piece 10 are measured by the temperature sensor 701 and humidity sensor 702 in the temperature and humidity measurement assembly 7.

[0081] Furthermore, once the test cavity 5 is formed, the temperature and / or humidity inside the test cavity 5 can be adjusted by the temperature and humidity control component 6.

[0082] Preferably, such as Figure 5 As shown, the temperature and humidity control assembly 6 includes a heater 601 and a temperature control switch 602, which is electrically connected to the heater 601 and the temperature sensor 701, respectively. The heater 601 is preferably made of an electric heating tube with external heat sink.

[0083] In this preferred embodiment, the temperature control switch 602 can automatically control whether the heater 601 works according to the set temperature and the temperature detected by the temperature sensor 701, so that the test cavity 5 reaches and maintains the set temperature.

[0084] Preferably, such as Figure 5 As shown, the temperature and humidity control assembly 6 includes a humidifier 603 and a humidity control switch 604, which is electrically connected to the humidifier 603 and the humidity sensor 702, respectively. The humidifier 603 is preferably a microwave humidifier.

[0085] In this preferred embodiment, the humidity control switch 604 can automatically control whether the humidifier 603 works based on the set humidity and the humidity detected by the humidity sensor 702, so that the test cavity 5 reaches and maintains the set humidity.

[0086] Furthermore, the temperature and humidity control component 6 also includes a data acquisition recorder 605, which is electrically connected to the temperature sensor 701, humidity sensor 702, and dial gauge 3 respectively, and can automatically record the readings of the temperature sensor 701, humidity sensor 702, and dial gauge 3.

[0087] Furthermore, the building material volume stability testing device also includes a bottom shell 8 with a box-shaped structure with an open top; a test platform 1 is installed at the opening of the bottom shell 1 and closes the opening; a heater 601 and / or a humidifier 603 are installed in the bottom shell 8; and a through hole 102 communicating with the bottom shell 8 is provided on the test platform 1.

[0088] For example, the bottom shell 8 is a hollow cubic box structure without a top cover. The bottom shell 8 is preferably made of a material that is resistant to high temperature and corrosion and has good sealing properties, such as stainless steel, aluminum alloy, steel plate, etc.

[0089] In a preferred embodiment, the through hole 102 on the test platform 1 can connect the bottom shell and the test cavity 5 above, so that the working effect of the heater 601 and humidifier 603 set in the bottom shell 8 can be quickly transmitted to the test cavity 5, thereby realizing rapid adjustment of the temperature and / or humidity in the test cavity 5.

[0090] The building material volume stability testing device of the present invention, by setting a support 2 at the specimen mounting position 101 on the test platform 1 and a dial gauge 3 on the support 2, can measure the length change of the test specimen 10 installed at the specimen mounting position 101. By installing a closed cover 4 on the test platform 1, the test specimen 10 is placed in a closed test cavity 5. Based on the data measured by the temperature and humidity measuring component 7 and the dial gauge 3, the change in length of the test specimen 10 with the temperature and humidity of the test environment can be calculated, thus completing the volume stability test. The building material volume stability testing device of the present invention can measure the length change of building material specimens under changes in temperature and humidity, explore the law of the change in length (volume) of building materials with changes in environmental conditions. The testing device has a simple structure, is convenient to measure, has high measurement accuracy, and is easy to popularize and apply.

[0091] In practical use, a preferred embodiment provides a method for testing the volume stability of building materials, which includes at least the following steps:

[0092] (1) The test piece 10 is installed on the corresponding test piece mounting position 101, and the probe of the dial gauge 3 corresponding to the test piece mounting position 101 is abutted against the top surface of the test piece 10.

[0093] (2) Install the sealing cover 4 on the test bench 1 and seal the test piece 10 in the test cavity 5; settling time t 0. The initial measurement parameters of the test piece 10, namely the temperature reading, are measured by the temperature and humidity measuring component 7 and the dial gauge 3. T 0. Humidity reading S 0 and dial gauge reading l 0.

[0094] (3) The temperature and / or humidity control component 6 adjusts the temperature and / or humidity in the test cavity 5 to the test set value; standing time t 1. The temperature and humidity measuring components 7 and the dial gauge 3 measure the test parameters of the test piece 10, namely the temperature reading. T 1. Humidity reading S 1 and dial indicator readings l 1.

[0095] resting time t 0、 t 1. Preferably, the settings are based on the material, size, and test cavity size of the test specimen, for example... t 0、 t The value range is between 0.5h and 72h, which allows the test piece 10 to fully adapt to the corresponding temperature and humidity environment.

[0096] (4) Calculate the change in length of the test piece using the following formula:

[0097] Δl =( T 1- T 0)· α · L -( l 1- l 0)

[0098] In the formula, Δl The change in length of the test piece 10; α The coefficient of linear expansion of the material of the vertically installed component 201; L The height of the horizontally mounted component 202 from the test platform surface 1.

[0099] In this embodiment, ( T 1- T 0)· α · L The change in length of the vertically installed component 201 due to changes in ambient temperature, with elongation as positive; the change in the reading of dial gauge 3 ( l 1- l 0) represents the change in the relative distance between the transverse mounting component 202 and the top surface 10 of the test piece, with an increase in relative distance being positive; the change in the length of the test piece 10 can be obtained by subtracting the latter from the former. Δl The elongation is positive. Since the length change of the test piece itself is small in this test, while the length of the bracket 2 will also change with the temperature and humidity of the test environment, this formula can eliminate the influence of temperature change on the vertical mounting component 201 of the bracket 2, and reduce the test error.

[0100] Preferably, the vertical mounting component 201 is made of a material whose volume is not affected by ambient humidity, such as stainless steel. By selecting a material whose volume is not affected by humidity, the deformation of the vertical mounting component 201 is controlled to change only with temperature, so that the above formula ( T 1- T 0)· α·L It can accurately calculate the length change of the vertically installed component 201, thereby improving the measurement of the length change of the test piece 10. Δl The calculation accuracy.

[0101] Furthermore, the coefficient of linear expansion of the vertically installed component 201 can be measured in advance through experiments. When the vertical mounting component 201 is made of a conventional material such as stainless steel, the coefficient of linear expansion of the vertical mounting component 201 of the bracket 2 can be obtained by consulting relevant specifications. α .

[0102] In this preferred embodiment, the influence of the deformation of the vertical mounting component 201 due to temperature changes on the measurement results is eliminated by the above formula, thus obtaining a more accurate length change of the test piece.Δl This reduces experimental errors.

[0103] Furthermore, the test method for the volume stability of building materials also includes the following procedures:

[0104] (5) The temperature and / or humidity control component 6 adjusts the temperature and / or humidity in the test cavity 5 to a new set value; settling time t 2. The temperature and humidity measuring components 7 and the dial gauge 3 measure the test parameters of the test piece 10, namely the temperature reading. T 2. Humidity reading S 2-micrometer reading l 2.

[0105] (6) Repeat step (5) continuously to obtain a series of test measurement parameters of the test specimen under environmental temperature and humidity changes, i.e., temperature readings. T m Humidity readings S m and dial indicator reading l m According to the formula Δl m =( T m - T 0)· α·L -( l m - l 0) Calculate the length change of the test piece 10 under a series of temperature and humidity conditions.

[0106] In this embodiment, Δl m For the test piece at a temperature of T m Humidity is S m The change in length relative to the initial environment under test conditions. Based on a series of recorded environmental temperature and humidity data and the calculated change in the length of the test piece, the variation law of the test piece's length with environmental temperature and humidity can be obtained, and consequently, the variation law of the test piece's volume with environmental temperature and humidity can also be obtained.

[0107] In practical use, the preferred embodiment also provides another method for testing the volume stability of building materials, which includes at least the following procedures:

[0108] (2.1) Prepare multiple sets of test specimens 10. Each set of test specimens 10 includes multiple test specimen units of the same specifications made of the same material, and test specimens 10 of different sets are made of different materials and of the same specifications.

[0109] (2.2) Install the test pieces on the test bench 1 corresponding to the first bracket 21 and the second bracket 22 respectively, and make the probe of the dial indicator 3 on each bracket abut against the test top surface of the corresponding test piece 10;

[0110] Different sets of specimen units are installed on the specimen mounting positions 101 corresponding to the second bracket 22. A 0、 B 0、 C 0、… X 0, where X is the th x Group of test pieces, x The number is an integer not less than 2; at the same time, at least one set of the same type of specimen is installed corresponding to multiple first supports 21. Y 1 、Y 2 、Y 3 …Y n Among them, type Y specimens are one type of specimen mounted on the second support, and n It is an integer not less than 2; in addition, the vertical mounting members 201 of at least two first supports 21 corresponding to each group of similar specimens are made of materials with different coefficients of linear expansion.

[0111] For example, a set of similar test pieces are installed corresponding to multiple first supports 21. A 1 、A 2 、A 3 、A 4 …A n, Alternatively, two sets of the same type of test specimens can be installed on multiple first supports 21. A 1 、A 2 、A 3 、A 4 …A n, and B 1 、B 2 、B 3 、B 4 …B n, .

[0112] (2.3) Install the sealing cover 4 on the test bench 1 and seal each test piece unit in the test cavity 5; settling time t 0. The initial measurement parameters of each group of test specimens are measured by the temperature and humidity measuring component 7 and each dial gauge 3, namely the temperature reading. T 0. Humidity reading S 0 and dial gauge reading l 00 , l 01 , l 02 …l 0n .

[0113] (2.4) Control the temperature and humidity regulating component 6 to adjust the temperature and / or humidity in the test cavity 5 to the test set value; settling time t 1. The temperature and humidity measuring components 7 and each dial gauge 3 measure the test parameters of each group of test specimens, namely the temperature readings. T 1. Humidity reading S 1 and readings of each dial indicator l 10 , l 11 , l 12 …l 1n. .

[0114] resting time t 0、 t 1. Preferably, the settings are based on the material, size, and test cavity size of the test specimen, for example... t 0、 t The value 1 can be between 0.5h and 72h, which allows the test piece 10 to fully adapt to the corresponding temperature and humidity environment.

[0115] (2.5) Calculate the length change of each specimen unit using the following formula:

[0116] Δl n =( T 1- T 0)· α n ·L n -( l 1n - l 0n )

[0117] In the formula, Δl n For each group n The length change of specimen unit number; α n For each group n The coefficient of linear expansion of the material of the vertical mounting component 201 of the support 2 corresponding to the test piece unit; L n For each group n The height of the horizontal mounting component 202 of the bracket 2 corresponding to the test piece unit from the test table surface 1.

[0118] (2.6) According to the Laida criterion / Grubbs criterion, outliers in the length variation of the test specimen units in the same group of test specimens are removed, and the average length variation of the remaining test specimen units is taken as the final length variation of the test specimens in the group.

[0119] In a preferred embodiment, different groups of test specimen units are measured by installing them on multiple test specimen mounting positions 101 corresponding to the second support 22, for example... Figure 6 In A 0 、B 0 … Compare their experimental results Δl A0 , Δl B0 … ( Δl A0 Group A, No. 0 The change in length of specimen unit number Δl B0 (And similarly thereafter), the differences in length changes of specimen units made of different materials under varying environmental temperature and humidity can be obtained; by installing specimen units of the same group on the specimen mounting positions 101 corresponding to the first support 21, for example... Figure 6 In A 1 、A 2 … Furthermore, since at least two of the vertical mounting components 201 in the first bracket 21 are made of materials with different coefficients of linear expansion, the influence of the coefficient of linear expansion of the vertical mounting component 201 of the bracket 2 on the test results can be obtained. Further, the test results of the same group of specimen units measured by the first bracket 21 and the second bracket 22 with the same coefficient of linear expansion can be compared, for example, by... Figure 6 Specimen unit in A 0 and A 1 or A 2 … or A n Calculated Δl A0 and Δl A1 or Δl A2 …Δl An By comparison, the influence of different support types on the length change of the specimen unit under environmental changes was obtained.

[0120] In this preferred embodiment, since the materials and specifications of the test specimens in the same group are all the same, under ideal conditions, the test specimen units (in this group) can be measured. Figure 6 In A 0 、A 1 、A 2 …An For example, the length changes should be equal or similar, but in actual experiments, various situations may arise that lead to different experimental results. Δl A0 , Δl A1 , Δl A2 …Δl An If the results are inconsistent, the test results of the same group of test specimens are processed according to the Laida criterion / Grubbs criterion to remove outliers, reduce test errors, and take the average of the remaining data as the final vertical length change of the group of test specimens. Δl A This improves the accuracy of test results.

[0121] Furthermore, this method for testing the volume stability of building materials also includes the following procedures:

[0122] (2.7) The temperature and / or humidity control assembly 6 adjusts the temperature and / or humidity in the test cavity 5 to the new set value; settling time t 2. The temperature and humidity measuring components 7 and each dial gauge 3 measure the test parameters of each group of test specimens, namely the temperature readings. T 2. Humidity reading S 2 and the readings of each dial indicator l 20 , l 21 , l 22 …l 2n. .

[0123] (2.8) Repeat step (2.7) continuously to obtain a series of test measurement parameters for each group of test specimens under varying environmental temperature and humidity conditions, i.e., temperature readings. T m Humidity readings S m and the readings of each dial indicator l m0 , l m1 , l m2 …l mn. According to the formula Δl mn =( T m - T 0)· α·L -( l mn - l 0nThe length changes of each specimen unit in each group of test specimens under a series of temperature and humidity conditions were calculated.

[0124] In this embodiment, Δl mn For each group n Each test piece unit was at a temperature of T m Humidity is S m The change in length relative to the initial environment under test conditions. Based on a series of recorded environmental temperature and humidity data and the calculated length changes of each specimen unit in each group of test specimens, sufficient data can be provided to study the differences in length changes of specimen units made of different materials under changes in environmental temperature and humidity, the influence of the linear expansion coefficient of different vertical mounting components 201 on the test results, and the influence of different bracket types on the length changes of specimen units under environmental changes.

[0125] Furthermore, by eliminating outliers in the length variation of test specimen units in the same group of test specimens in each test environment according to the Laida / Grubbs criterion, and taking the average of the remaining length variation of test specimen units as the final length variation of the group of test specimens, the variation law of the length of each group of test specimens with ambient temperature and humidity can also be obtained.

[0126] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A test device for the volume stability of building materials, characterized in that, include: The test bench has multiple specimen mounting positions for mounting the specimens to be tested, and a bracket consisting of vertical mounting components and horizontal mounting components is provided corresponding to each specimen mounting position. The bracket includes multiple first brackets, which can be installed on the test bench and correspond one-to-one with a single specimen mounting position. The vertical mounting components of at least two first brackets are made of materials with different coefficients of linear expansion. The vertical mounting component is vertically mounted on the test bench; the horizontal mounting component is vertically mounted on the vertical mounting component, and a dial indicator is provided on the horizontal mounting component; the measuring rod of the dial indicator is parallel to the vertical mounting component, so that the measuring head of the dial indicator can correspondingly abut against the top surface of the test specimen installed in the corresponding specimen mounting position; A closed enclosure, which can be installed on the test bench surface and form a closed test cavity with the test bench surface; A temperature and humidity control component is provided corresponding to the test cavity and is used to adjust the temperature and / or humidity inside the test cavity; A temperature and humidity measurement assembly, comprising a combined temperature sensor and a humidity sensor, for measuring temperature and humidity in the test environment parameters of the test specimen; Based on the data measured by the temperature and humidity measuring components and the dial gauge, the change in the length of the test piece as a function of ambient temperature and humidity is calculated, and the amount of length change of the test piece is calculated using the following formula: In the formula, Temperature was measured after the test was completed; The initial measured temperature before temperature and humidity adjustment; The change in length of the test piece; The coefficient of linear expansion of the material of the vertically installed component; L The height of the horizontally mounted component from the test bench surface; The dial gauge reading before temperature and humidity adjustment; The dial gauge reading is shown after the test is completed.

2. The building material volume stability testing device according to claim 1, characterized in that, The installation height of the horizontal mounting component on the vertical mounting component is adjustable.

3. The building material volume stability testing device according to claim 1, characterized in that, The specimen mounting positions are multiple, and the bracket also includes at least one second bracket; The second bracket can be installed on the test platform and correspond to multiple specimen mounting positions simultaneously.

4. The building material volume stability testing device according to any one of claims 1 to 3, characterized in that, The temperature and humidity regulating component includes a heater and a temperature control switch, wherein the temperature control switch is electrically connected to the heater and the temperature sensor respectively. and / or The temperature and humidity control assembly includes a humidifier and a humidity control switch, wherein the humidity control switch is electrically connected to the humidifier and the humidity sensor, respectively.

5. The building material volume stability testing device according to claim 4, characterized in that, The temperature and humidity control component also includes a data acquisition and recording device, which is electrically connected to the temperature sensor, humidity sensor, and dial gauge, respectively.

6. The building material volume stability testing device according to any one of claims 4, characterized in that, It also includes a bottom shell with a box-like structure that has an open top; The test platform is installed at the opening of the bottom shell and closes the opening; the heater and / or humidifier are disposed in the bottom shell; and a through hole communicating with the bottom shell is provided on the test platform.

7. A method for testing the volume stability of building materials, characterized in that, This method utilizes the building material volume stability testing apparatus described in claim 1 or 2, and includes the following steps: (1) Install the test piece on the corresponding test piece mounting position and place the probe of the dial indicator corresponding to the test piece mounting position against the top surface of the test piece; (2) Install a sealing cover on the test bench and seal the test piece inside the test cavity; settling time t 0. The initial measurement parameters of the test specimen, i.e., the temperature reading, are measured by the temperature and humidity measuring components and the dial gauge. T 0. Humidity reading S 0 and dial gauge reading l 0; (3) The temperature and / or humidity control components are used to adjust the temperature and / or humidity in the test cavity to the test set value; settling time t 1. The test parameters of the test specimen, namely the temperature reading, are measured using a temperature and humidity measuring component and a dial gauge. T 1. Humidity reading S 1 and dial indicator readings l 1; (4) Calculate the change in length of the test piece using the following formula: In the formula, The change in length of the test piece; The coefficient of linear expansion of the material of the vertically installed component; L The height of the horizontally mounted component from the test bench surface.

8. A method for testing the volume stability of building materials, characterized in that, This method utilizes the building material volume stability testing device described in claim 3, and includes the following steps: (1) Prepare multiple sets of test specimens. Each set of test specimens includes multiple test specimen units of the same specifications made of the same material, and the test specimens of different sets are made of different materials and of the same specifications. (2) Install the test piece on the test bench corresponding to the first bracket and the second bracket respectively, and make the dial indicator probe on each bracket abut against the test top surface of the corresponding test piece; Different sets of specimen units are installed at the specimen mounting positions corresponding to the second support. A 0、 B 0、 C 0 …X 0, where X is the th x Group of test pieces, x The number is an integer not less than 2; at the same time, at least one set of the same type of specimen is installed for each of the multiple first supports. Y 1. Y 2. Y 3 …Y n Among them, type Y specimens are one type of specimen mounted on the second support, and n It is an integer not less than 2; in addition, the vertical mounting components of at least two first supports corresponding to each group of specimens of the same type are made of materials with different coefficients of linear expansion; (3) Install a closed cover on the test bench and enclose each test piece in the test cavity; settling time t 0. The initial measurement parameters of each group of test specimens are measured by the temperature and humidity measuring components and each dial indicator, namely the temperature reading. T 0. Humidity reading S 0 and dial gauge reading l 00 , l 01 , l 02 …l 0n ; (4) The temperature and / or humidity control components are used to adjust the temperature and / or humidity in the test cavity to the test set value; settling time t 1. The temperature and humidity measuring components and dial gauges are used to measure the test parameters of each group of test specimens, namely the temperature readings. T 1. Humidity reading S 1 and readings of each dial indicator l 10 , l 11 , l 12 …l 1n ; (5) Calculate the change in length of the test piece using the following formula: In the formula, For each group n The length variation of each specimen unit; For each group n The coefficient of linear expansion of the material of the vertical mounting components of the support corresponding to each specimen unit; L n For each group n The height of the horizontal mounting component of the bracket corresponding to each specimen unit from the test bench surface; (6) According to the Laida criterion / Grubbs criterion, outliers in the length variation of the test unit in the same group of test specimens are removed, and the average length variation of the remaining test unit is taken as the final length variation of the test specimen in the group.

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