阅读说明：本技术 非恒温环境下混凝土自收缩试验装置及其工作方法 (Concrete self-shrinkage test device in non-constant temperature environment and working method thereof ) 是由 付欢 吴靖江 孟庆鑫 张征 毋存粮 郭进军 叶雨山 郑元勋 张永 景玉婷 尹贺军 于 2021-09-29 设计创作，主要内容包括：本发明提出了一种非恒温环境下混凝土自收缩试验装置及其工作方法,用以解决现有混凝土早期收缩的测量过程中存在的只能在恒温的调节下才能进行测量的技术问题。本发明通过对现有自收缩试验装置进行改进,增加温度补偿系统,利用信号分离系统消除在进行自收缩试验时温度变化引起的传感器电信号变化的部分,将消除后的电信号转换为数值信号进行计算并输出混凝土的早期收缩值,在试验时对混凝土试模预处理,消除外部影响,使用塑料薄膜将混凝土完全密封,提升测量准确性,从实际采集到的混凝土收缩的数据信号中减去由于温度变化所引起的正弦函数形式的数据信号,消除温度影响,根据数字信号计算混凝土早期收缩值并输出曲线图供工作人员使用。(The invention provides a concrete self-contraction test device in a non-constant temperature environment and a working method thereof, which are used for solving the technical problem that the measurement can be carried out only under the condition of constant temperature adjustment in the existing measurement process of the early contraction of concrete. The invention improves the existing self-contraction test device, adds a temperature compensation system, eliminates the part of the electric signal change of the sensor caused by the temperature change during the self-contraction test by using a signal separation system, converts the eliminated electric signal into a numerical signal to calculate and output the early contraction value of the concrete, preprocesses the concrete test mold during the test, eliminates the external influence, completely seals the concrete by using a plastic film, improves the measurement accuracy, subtracts a data signal in a sine function form caused by the temperature change from the actually acquired data signal of the concrete contraction, eliminates the temperature influence, calculates the early contraction value of the concrete according to the digital signal and outputs a curve chart for workers to use.)

1. The utility model provides a concrete self-contraction test device under non-constant temperature environment, its characterized in that, includes concrete examination mould (1), signal acquisition mechanism, temperature compensation unit (7) and signal processing unit (11), be provided with handle (2) on the both sides wall of concrete examination mould (1), signal acquisition mechanism installs on concrete examination mould (1), temperature compensation unit (7) are connected with signal acquisition mechanism, signal processing unit (11) are connected with temperature compensation unit (7).

2. The concrete self-contraction test device under the non-constant temperature environment according to claim 1, wherein the signal acquisition mechanism comprises a sensor probe (3), a clamp spring (4), a probe fixer (5) and a metal reflection target (6), the metal reflection target (6) is inserted into the concrete test mold (1), the probe fixer (5) is fixed on the side wall of the concrete test mold (1), the sensor probe (3) is fixedly connected with the probe fixer (5) through the clamp spring (4), the receiving end of the sensor probe (3) is matched with the metal reflection target (6), and the sensor probe (3) is connected with the temperature compensation unit (7) through a signal transmission lead (14).

3. The concrete self-contraction test device under the non-constant temperature environment according to claim 2, wherein the temperature compensation unit (7) comprises a first signal receiving module (801), a signal separation module (9) and a signal output module (10), the first signal receiving module (801) is connected with the sensor probe (3) through a signal transmission lead (14), the first signal receiving module (801), the signal separation module (9) and the signal output module (10) are sequentially connected through a signal transmission lead (14), and the signal output module (10) is connected with the signal processing unit (11) through a signal transmission lead (14).

4. The concrete self-contraction test device under the non-constant temperature environment according to claim 3, wherein the signal processing unit (11) comprises a second signal receiving module (802), a signal conversion module (12) and a terminal processing module (13), the second signal receiving module (802) is connected with the signal output module (10) through a signal transmission lead (14), and the second signal receiving module (802), the signal conversion module (12) and the terminal processing module (13) are sequentially connected through the signal transmission lead (14).

5. The working method of the concrete self-contraction test device under the non-constant temperature environment according to any one of claims 1 to 4, characterized by comprising the following steps:

s1, cleaning the concrete test mold (1), brushing a layer of lubricant on the inner wall of the concrete test mold (1), arranging an isolation layer in the concrete test mold (1), brushing a layer of lubricant, laying a plastic film capable of wrapping a test piece in the concrete test mold (1), and enabling the plastic film to be tightly attached to the isolation layer;

s2, placing and fixing metal reflection targets (6) on the inner sides of two ends of the concrete test mold (1), pouring the mixed fresh concrete into the concrete test mold (1), vibrating and compacting, and sealing the concrete to be tested by using a plastic film;

s3, after the concrete to be detected is initially set, pulling out a polytetrafluoroethylene plate on the side surface of the concrete test mold (1), fixing a probe fixer (5) on the side wall of the concrete test mold (1), and connecting and adjusting the distance between a sensor probe (3) and a metal reflection target (6) by using a snap spring (4) so that a signal acquisition mechanism can acquire a data signal of the concrete to be detected;

s4, placing the concrete to be tested and the concrete test mould (1) in a test environment by using the handle (2), starting the temperature compensation unit (7) and the signal processing unit (11), determining a sampling time interval, and starting to automatically record the shrinkage deformation of the concrete to be tested.

6. The working method of the concrete self-contraction test device under the non-constant temperature environment according to claim 5, wherein the lubricant in the step S1 is vaseline, vegetable oil or engine oil, the thickness of the lubricant is 1mm, and the isolation layer is a polytetrafluoroethylene plate or a fluorinated ethylene propylene plate; the working method of the sensor probe (3) and the metal reflective target (6) in the step S3 comprises the following steps: the sensor probe (3) transmits pulses to the metal reflection target (6), the metal reflection target (6) reflects the pulses to the sensor probe (3), and the sensor probe (3) transmits reflected pulse signals to the temperature compensation unit (7).

7. The working method of the concrete self-contraction test device under the non-constant temperature environment according to claim 5, wherein the working method of the temperature compensation unit (7) in the step S4 comprises the following steps:

y1, a first signal receiving module (801) receives data signals of the concrete to be detected, which are collected and transmitted by the sensor probe (3), and the first signal receiving module (801) transmits the signals to a signal separation module (9);

y2, a signal separation module (9) receives and processes the signal transmitted by the first signal receiving module (801), separates out the temperature influence signal in the acquired signal, and transmits the signal without the temperature influence to a signal output module (10);

y3 and the signal output module (10) transmits the received signal with the temperature influence eliminated to the signal processing unit (11).

8. The working method of the concrete self-contraction testing device under the non-constant temperature environment according to claim 7, wherein the method for separating the temperature-affected signal in the acquired signal in the step Y2 is to subtract the data signal in the form of a sine function caused by the external temperature change from the data signal of the concrete contraction actually acquired, and the formula of the signal elimination is as follows:

H(t)＝D(t)-F(t)

F(t)＝Asin(Bt+C)+E

h (t) is a data signal for eliminating temperature influence at the time t, D (t) is a data signal actually measured at the time t, F (t) is a data signal generated due to temperature influence at the time t, A, B, C and E are all influence parameters of temperature on the data signal, and the influence parameters are related to the temperature, the humidity and the type of a measuring material of a measuring environment.

9. The working method of the concrete self-contraction test device under the non-constant temperature environment according to claim 5, wherein the working method of the signal processing unit (11) in the step S4 comprises the following steps:

t1, the second signal receiving module (802) receives the signal which is transmitted by the signal output module (10) and is subjected to temperature influence elimination, and the second signal receiving module (802) transmits the signal to the signal conversion module (12);

t2, the signal conversion module (12) converts the received signal without the temperature influence into a digital signal and transmits the digital signal to the terminal processing module (13);

t3, the terminal processing module (13) converts the received digital signals into curve images and calculates the early shrinkage value of the concrete.

10. The working method of the concrete self-contraction test device under the non-constant temperature environment according to claim 9, wherein in the calculation of the early contraction value of the concrete in the step T3, the contraction rate of the concrete is calculated according to the following formula:

wherein epsilon_tThe self-shrinkage rate of the concrete at the time t; l is_tThe length of the test piece at the time t is in mm; l is₀Is the specimen reference length in mm.

Technical Field

The invention relates to the technical field of concrete building construction, in particular to a concrete self-contraction test device in a non-constant temperature environment and a working method thereof.

Background

Concrete materials are widely used in various fields of infrastructure construction due to their excellent compressive properties. But it also has a disadvantage of poor tensile properties. Especially in the northwest of China, the environmental conditions are severe: dry and rain less, and the temperature difference is larger. When the construction and maintenance of concrete are performed in such an environment, the concrete is easily cracked due to temperature stress and shrinkage stress caused by drying. Once the concrete cracks, harmful substances in the environment can be provided with a channel for corroding the inside of the concrete, so that the steel bars are corroded, the concrete protective layer is peeled off, and the safety and the durability of the concrete structure are seriously affected. It is therefore of great importance how to accurately measure the early shrinkage properties of concrete.

According to GB/T50082-2009 standard of test methods for long-term performance and durability of common concrete, the commonly used method for measuring early shrinkage of concrete comprises the following steps: contact and non-contact methods. The non-contact method has simple operation and high measurement precision, can continuously and automatically monitor the early deformation of the concrete, and is used by more and more scholars for measuring the early shrinkage characteristic of the concrete material. The non-contact concrete shrinkage measuring instrument reflects the distance change between the end of the sensor and the metal reflecting target embedded in the concrete test piece through the change of the electric signal output by the sensor, thereby calculating the shrinkage value of the concrete. The shrinkage measuring device can obtain a relatively ideal effect under a laboratory environment (constant temperature), but when the external environment changes, especially the change of the temperature (expansion with heat and contraction with cold) can generate a relatively large influence on the early shrinkage value of the concrete, thereby causing interference on the measurement and analysis of the real shrinkage characteristic of the concrete.

Therefore, the worker needs a measuring device and a measuring method for the early shrinkage of the concrete, so that the early shrinkage test of the concrete is not limited to the standard environment of a constant-temperature laboratory, and can be applied to the actual engineering environment without constant temperature.

Disclosure of Invention

The invention provides a concrete self-contraction test device under a non-constant temperature environment and a working method thereof, aiming at the technical problem that the measurement can only be carried out under the condition of constant temperature in the existing concrete early contraction measurement process.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the utility model provides a concrete self contraction test device under non-constant temperature environment, includes that concrete tries mould, signal acquisition mechanism, temperature compensation unit and signal processing unit, is provided with the handle on the both sides wall that concrete tried mould, and signal acquisition mechanism installs on concrete tries mould, and temperature compensation unit is connected with signal acquisition mechanism, and signal processing unit is connected with the temperature compensation unit.

Furthermore, the signal acquisition mechanism comprises a sensor probe, a clamp spring, a probe fixer and a metal reflection target, the metal reflection target is inserted into the concrete test mould, the probe fixer is fixed on the side wall of the concrete test mould, the sensor probe is fixedly connected with the probe fixer through the clamp spring, a receiving end of the sensor probe is matched with the metal reflection target, and the sensor probe is connected with the temperature compensation unit through a signal transmission lead.

Furthermore, the temperature compensation unit comprises a first signal receiving module, a signal separation module and a signal output module, the first signal receiving module is connected with the sensor probe through a signal transmission lead, the first signal receiving module, the signal separation module and the signal output module are sequentially connected through a signal transmission lead, and the signal output module is connected with the signal processing unit through a signal transmission lead.

Furthermore, the signal processing unit comprises a second signal receiving module, a signal conversion module and a terminal processing module, the second signal receiving module is connected with the signal output module through a signal transmission lead, and the second signal receiving module, the signal conversion module and the terminal processing module are sequentially connected through a signal transmission lead.

The working method of the concrete self-contraction test device in the non-constant temperature environment comprises the following steps:

s1, cleaning the concrete test mold, brushing a layer of lubricant on the inner wall of the concrete test mold, arranging an isolation layer in the concrete test mold, brushing a layer of lubricant, laying a plastic film capable of wrapping the test piece in the concrete test mold, and enabling the plastic film to be tightly attached to the isolation layer;

s2, placing and fixing metal reflection targets on the inner sides of the two ends of the concrete test mold, pouring the mixed fresh concrete into the concrete test mold, vibrating and compacting, and sealing the concrete to be tested by using a plastic film;

s3, after the concrete to be detected is initially set, pulling out the polytetrafluoroethylene plate on the side face of the concrete test mold, fixing a probe fixer on the side wall of the concrete test mold, and connecting and adjusting the distance between a sensor probe and a metal reflection target by using a snap spring so that a signal acquisition mechanism can acquire a data signal of the concrete to be detected;

and S4, placing the concrete to be tested and the concrete test mould in a test environment by using a handle, starting the temperature compensation unit and the signal processing unit, determining a sampling time interval, and starting to automatically record the shrinkage deformation of the concrete to be tested.

Further, the lubricant in the step S1 is vaseline, vegetable oil or engine oil, the thickness of the lubricant is 1mm, and the isolation layer is a polytetrafluoroethylene plate or a polyperfluoroethylene propylene plate; the working method of the sensor probe and the metal reflective target in the step S3 comprises the following steps: the sensor probe transmits pulses to the metal reflection target, the metal reflection target reflects the pulses to the sensor probe, and the sensor probe transmits reflected pulse signals to the temperature compensation unit.

Further, the operation method of the temperature compensation unit in step S4 includes the following steps:

y1, the first signal receiving module receives and transmits data signals of the concrete to be detected, which are acquired and transmitted by the sensor probe, and the first signal receiving module transmits the signals to the signal separating module;

y2, the signal separation module receives and processes the signal transmitted by the first signal receiving module, separates out the temperature influence signal in the acquired signal, and transmits the signal without the temperature influence to the signal output module;

and Y3, the signal output module transmits the received signal with the temperature influence eliminated to the signal processing unit.

Further, the method for separating the temperature-affected signal from the acquired signal in step Y2 is to subtract the data signal in the form of a sine function caused by the external temperature change from the data signal of the concrete shrinkage actually acquired, and the formula of the signal elimination is as follows:

H(t)＝D(t)-F(t)

F(t)＝Asin(Bt+C)+E

h (t) is a data signal for eliminating temperature influence at the time t, D (t) is a data signal actually measured at the time t, F (t) is a data signal generated due to temperature influence at the time t, A, B, C and E are all influence parameters of temperature on the data signal, and the influence parameters are related to the temperature, the humidity and the type of a measuring material of a measuring environment.

Further, the operating method of the signal processing unit in step S4 includes the following steps:

t1, the second signal receiving module receives the signal which is transmitted by the signal output module and is subjected to temperature influence elimination, and the second signal receiving module transmits the signal to the signal conversion module;

t2, the signal conversion module converts the received signal without the temperature influence into a digital signal and transmits the digital signal to the terminal processing module;

and T3, converting the digital signal into a curve image by the terminal processing module, and calculating the early shrinkage value of the concrete.

Further, in the calculation of the early shrinkage value of the concrete in the step T3, the shrinkage rate of the concrete is calculated according to the formula:

wherein epsilon_tThe self-shrinkage rate of the concrete at the time t; l is_tThe length of the test piece at the time t is in mm; l is₀Is the specimen reference length in mm.

The invention has the beneficial effects that:

1. the invention improves the existing self-contraction test device, adds a temperature compensation system, eliminates the part of the sensor electric signal change caused by the temperature change during the self-contraction test by using a signal separation system, converts the eliminated electric signal into a numerical signal to calculate and output the early contraction value of the concrete, and ensures the accuracy of the result during the self-contraction test of the concrete under the non-constant temperature condition, particularly the non-constant temperature condition.

2. In the working method, firstly, the concrete test mold is processed before the concrete test to be tested is carried out, so that the free shrinkage of the concrete is ensured, and the external influence is eliminated; secondly, the concrete is completely sealed by using the plastic film, so that the influence of the external environment on the concrete to be measured is reduced to the minimum, and the measurement accuracy is improved; and thirdly, subtracting the data signal in the form of a sine function caused by the change of the external temperature from the actually acquired data signal of the concrete shrinkage, eliminating the temperature influence, further improving the measurement accuracy, calculating the early shrinkage value of the concrete according to the digital signal and outputting a curve graph for the use of workers.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 is a flow chart of the working method of the present invention.

FIG. 3 is a self-shrinkage curve chart of the concrete of the present invention before eliminating the temperature effect in the self-shrinkage test.

FIG. 4 is a graph showing the self-shrinkage curve of the concrete of the present invention after eliminating the temperature effect in the self-shrinkage test.

In the figure, 1-concrete test, 2-handle, 3-sensor probe, 4-clamp spring, 5-probe fixer, 6-metal reflection target, 7-temperature compensation unit, 801-first signal receiving module, 802-second signal receiving module, 9-signal separation module, 10-signal output module, 11-signal processing unit, 12-signal conversion module, 13-terminal processing module and 14-signal transmission lead.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

Example 1

A concrete self-contraction test device under non-constant temperature environment is shown in figure 1 and comprises a concrete test mold 1, a signal acquisition mechanism, a temperature compensation unit 7 and a signal processing unit 11, wherein handles 2 are arranged on two side walls of the concrete test mold 1, the signal acquisition mechanism is installed on the concrete test mold 1, the temperature compensation unit 7 is connected with the signal acquisition mechanism, and the signal processing unit 11 is connected with the temperature compensation unit 7. Concrete test 1 is used for filling and holds the concrete that awaits measuring, handle 2 is used for constructor to remove concrete test 1 and the concrete that awaits measuring as required, signal acquisition mechanism is used for acquireing the data signal when the concrete that awaits measuring self-contraction, temperature compensation unit 7 is used for the data signal of receiving signal acquisition mechanism transmission and eliminates the temperature influence, the data information of temperature influence is eliminated in the output, signal processing unit 11 is used for receiving the data information of eliminating the temperature influence that temperature compensation unit 7 transmitted and exports early shrinkage value information of concrete according to data information.

Further, as shown in fig. 1, the signal acquiring mechanism includes a sensor probe 3, a snap spring 4, a probe fixer 5 and a metal reflection target 6, the metal reflection target 6 is inserted into the concrete test mold 1, the probe fixer 5 is fixed on the side wall of the concrete test mold 1, the sensor probe 3 is fixedly connected with the probe fixer 5 through the snap spring 4, a receiving end of the sensor probe 3 is matched with the metal reflection target 6, and the sensor probe 3 is connected with the temperature compensating unit 7 through a signal transmission lead 14. The clamp spring 4 is used for adjusting the distance between the sensor probe 3 and the metal reflection target 6 and improving the measurement precision, the probe fixer 5 is used for combining the sensor probe 3, the clamp spring 4 and the concrete test mould 1 into a whole, so that the sensor probe 3 can conveniently send pulse signals to the metal reflection target 6 and receive the pulse signals reflected by the metal reflection target 6, the working stability is improved, the sensor probe 3 can conveniently obtain data signals of the distance change between the sensor probe 3 and the metal reflection target 6, and the data signals are transmitted to the temperature compensation unit 7 through the signal transmission lead 14.

Further, as shown in fig. 1, the temperature compensation unit 7 includes a first signal receiving module 801, a signal separation module 9, and a signal output module 10, the first signal receiving module 801 is connected to the sensor probe 3 through a signal transmission wire 14, the first signal receiving module 801, the signal separation module 9, and the signal output module 10 are connected in sequence through the signal transmission wire 14, and the signal output module 10 is connected to the signal processing unit 11 through the signal transmission wire 14. The first signal receiving module 801 is configured to receive a data signal transmitted by the sensor probe 3 through the signal transmission wire 14 and transmit the data signal to the signal separating module 9, the signal separating module 9 is configured to receive the data signal transmitted by the first signal receiving module 801 through the signal transmission wire 14, separate and eliminate a temperature-affected signal in the obtained data signal, transmit the data signal without the temperature effect to the signal output module 10, and the signal output module 10 is configured to receive the data signal without the temperature effect transmitted by the signal separating module 9 through the signal transmission wire 14 and transmit the data signal to the signal processing unit 11.

Further, as shown in fig. 1, the signal processing unit 11 includes a second signal receiving module 802, a signal converting module 12 and a terminal processing module 13, the second signal receiving module 802 is connected to the signal output module 10 through a signal transmission wire 14, and the second signal receiving module 802, the signal converting module 12 and the terminal processing module 13 are connected in sequence through the signal transmission wire 14. The second signal receiving module 802 is configured to receive the data signal, which is transmitted by the signal output module 10 through the signal transmission wire 14 and is subjected to temperature influence elimination, and transmit the data signal to the signal conversion module 12, the signal conversion module 12 is configured to receive the data signal, which is transmitted by the second signal receiving module 802 through the signal transmission wire 14 and is subjected to temperature influence elimination, convert the obtained data signal, that is, the electric signal, subjected to temperature influence elimination into a digital signal, transmit the digital signal after conversion to the terminal processing module 13, the terminal processing module 13 is configured to receive the digital signal, which is transmitted by the signal conversion module 12 through the signal transmission wire 14, calculate an early concrete shrinkage value according to the digital signal, and output a graph for use by a worker.

Example 2

According to the concrete self-contraction test device in the non-constant temperature environment in embodiment 1, this embodiment provides a working method of the concrete self-contraction test device in the non-constant temperature environment, as shown in fig. 2, including the following steps:

s1, cleaning the concrete test mold 1, brushing a layer of lubricant on the inner wall of the concrete test mold 1, arranging an isolation layer in the concrete test mold 1, brushing a layer of lubricant, laying a plastic film capable of wrapping a test piece in the concrete test mold 1, and enabling the plastic film to be tightly attached to the isolation layer. Specifically, in this embodiment, before the test, five isolation layers need to be respectively placed on five inner surfaces of the concrete test mold 1, and a lubricant is uniformly applied to two sides of the isolation layers, so as to ensure that a gap is left between the concrete to be tested and the inner side surface of the concrete test mold 1 during the test, the lower surface of the concrete to be tested is kept smooth, and the free shrinkage of the concrete is ensured.

It should be noted that in this embodiment, the lubricant is vaseline having a thickness of 1mm, and in other embodiments of the present invention, other substances such as vegetable oil or engine oil may be used as the lubricant as long as the object of the present invention is achieved.

It should be noted that, in this embodiment, the isolation layer is a teflon plate, and in other embodiments of the present invention, other structures such as a polyperfluoroethylene propylene plate can be used as the isolation layer as long as the purpose of the present invention is achieved.

S2, placing and fixing the metal reflection targets 6 on the inner sides of the two ends of the concrete test mold 1, pouring the mixed fresh concrete into the concrete test mold 1, vibrating to be compact, and sealing the concrete to be tested by using a plastic film. Specifically speaking, the concrete to be measured is completely sealed by the plastic film, so that the influence of the external environment on the concrete to be measured is reduced to the minimum, and the measurement accuracy is improved.

S3, after the concrete is initially set, pulling out the polytetrafluoroethylene plate on the side surface of the concrete test mold 1, fixing the probe fixer 5 on the side wall of the concrete test mold 1, and connecting and adjusting the distance between the sensor probe 3 and the metal reflection target 6 by using the snap spring 4 to enable the signal acquisition mechanism to acquire the data signal of the concrete to be measured. Specifically, the pulse is transmitted to the metal reflection target 6, the metal reflection target 6 reflects the pulse to the sensor probe 3, the sensor probe 3 transmits the reflected pulse signal to the temperature compensation unit 7, the reflected pulse is transmitted and received by the sensor probe 3 so as to obtain the distance change between the sensor probe 3 and the metal reflection target 6, and then the self-contraction change of the concrete to be measured is expressed through the data signal.

S4, placing the concrete to be tested and the concrete test mould 1 together in a test environment by using the handle 2, starting the temperature compensation unit 7 and the signal processing unit 11, determining a sampling time interval, and starting to automatically record the shrinkage deformation of the concrete to be tested.

Specifically, the operation method of the temperature compensation unit 7 in step S4 includes the following steps:

y1, a first signal receiving module 801 receives data signals of the concrete to be detected collected and transmitted by a sensor probe 3, the first signal receiving module 801 transmits the signals to a signal separating module 9, the early self-contraction value of the concrete in the non-constant temperature environment is the influence of the combined action of the self-contraction of the concrete and the external temperature change, and the data signals of the temperature influence of the external periodic temperature change on the concrete contraction value in the form of a sine function are separated by subtracting the data signals in the form of the sine function caused by the external temperature change from the actually collected data signals of the concrete contraction, wherein the formula of signal elimination is as follows:

H(t)＝D(t)-F(t)

F(t)＝Asin(Bt+C)+E

h (t) is a data signal for eliminating temperature influence at the moment t, D (t) is a data signal actually measured at the moment t, F (t) is a data signal generated due to temperature influence at the moment t, the data signal generated due to the temperature influence is obtained by calculating a sine function, constants A, B, C and E in the sine function are parameters for influencing the data signal by temperature, and the parameters are related to the temperature, the humidity and the type of a measuring material of a measuring environment.

Y2, the signal separation module 9 receives and processes the signal transmitted by the first signal receiving module 801, separates out a temperature-affected signal from the acquired signal, and transmits the signal without the temperature effect to the signal output module 10; y3 and the signal output module 10 transmit the received signal without the temperature influence to the signal processing unit 11.

Further, the operating method of the signal processing unit 11 in step S4 includes the following steps:

t1, the second signal receiving module 802 receives the signal transmitted by the signal output module 10 after the temperature influence is eliminated, and the second signal receiving module 802 transmits the signal to the signal conversion module 12;

t2, the signal conversion module 12 converts the received signal without the temperature influence into a digital signal and transmits the digital signal to the terminal processing module 13;

t3, the terminal processing module 13 converts the received digital signal into a curve image, and calculates the early shrinkage value of the concrete, where in the calculation of the early shrinkage value of the concrete, the shrinkage factor calculation formula of the concrete is:

wherein epsilon_tThe self-shrinkage rate of the concrete at the time t; l is_tThe length of the concrete sample to be measured at the time t is obtained by a data signal of the distance change between the sensor probe 3 and the metal reflection target 6, and the unit is mm; l is₀The length of the concrete sample to be tested is the same as that of the concrete test mould 1, and the unit is mm.

It should be noted that, in the concrete self-contraction test performed in this embodiment, the length of the concrete to be tested is 515mm, the height of the concrete is 100mm, the distance between the metal reflective targets 6 is 40mm, the self-contraction test is performed under two conditions of using the temperature compensation unit 7 and not using the temperature compensation unit 7, the graphs output by the signal processing unit 11 are respectively shown in fig. 3 and 4, and it can be easily seen from a comparison between fig. 3 and 4 that after the temperature influence signal is eliminated, the self-contraction curve of the concrete in the self-contraction test is changed from an irregular curve to a regular curve, which is beneficial to research on the early self-contraction change of the concrete.

It should be noted that, in practical experiments, it was found that the change of humidity has little influence on the self-contraction test of concrete, so that the self-contraction test of concrete can be performed in a non-constant temperature environment by using the device and the working method in the embodiment.

The structure of the concrete self-contraction test device used in this embodiment in the non-constant temperature environment is the same as that in embodiment 1, and is not described herein again.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.