Performance testing system and performance testing method of concrete structure in water vapor environment

Abstract

The present invention relates to a performance detection system and a performance detection method for a concrete structure in a water vapor environment. The performance detection system includes a sample storage container, a detection unit, a solution storage container, a pumping pipeline, and an exhaust pipeline. The pumping pipeline is provided with a delivery pump, and the exhaust pipeline is provided with a suction pump. The performance detection system also includes at least two liquid adding containers and a control unit. At least one liquid adding container is a distilled water storage container, and at least one liquid adding container is a chemical solution storage container. A liquid adding pipeline is provided between each liquid adding container and the solution storage container, and a liquid adding pump is provided on the liquid adding pipeline. The control unit includes a humidity sensor for detecting the ambient humidity in the storage cavity and a detector for detecting the concentration of chemical solutes in the solution storage container. The control unit also includes a controller. The controller controls the start-up of the suction pump and the delivery pump in response to the value of the humidity sensor. The controller also controls the start-up of the corresponding liquid adding pump in response to the value of the detector.

Description

Technical Field

[0001] The present invention generally relates to the technical field of control and regulation systems during concrete performance testing, and more specifically to an automatic control and regulation method in a performance testing system and method for concrete structures in a water vapor environment. Background Art

[0002] Concrete structures that are in or near a water vapor environment for a long time are prone to structural damage. This damage involves many concrete structures, including roads, bridges, dams, spillways and houses.

[0003] Under the action of water vapor, the pore structure of existing concrete will cause micro-scale cracks to change. Micro-scale cracks gradually evolve into larger, wider, longer, and deeper macro-cracks, further reducing the integrity of the structure and intensifying the penetration of water and ions. Different types of water vapor, air humidity, chemical composition, and corrosive salt ion content have different effects on the durability and service life of concrete structures. Among them, the corrosive effects of chloride ions and sulfate ions are the most damaging to concrete structures. Their corrosive effects lead to rusting of steel bars within the concrete structure, expansion of the concrete structure, and cracking. The high salt ion content, high humidity, and rapid corrosion rate will also accelerate the deterioration of the corresponding mechanical properties of the concrete structure, such as deformation resistance and strength, resulting in the actual service life of the concrete structure being less than its design life.

[0004] For example, in a coastal area of ​​southern China, the pile foundation of a bridge was significantly exposed during a period of riverbed elevation decline. While the internal reinforcement of two piers near the waterline remained intact, the surface concrete structure became loose, cracked, and prone to falling due to long-term exposure to moisture. Another example is the foundation of an offshore concrete bridge, which experienced significant humidity fluctuations and corrosive attack from sulfate and chloride ions during water vapor circulation. This reduced overall stiffness, leading to rapid overall and uneven settlement. To ensure timely maintenance and repair, and ensure safe driving, relevant departments shortened monitoring and maintenance cycles, significantly increasing maintenance costs.

[0005] Among the existing research results, most are distributed in the concrete structure itself, such as its performance, erosion rate, and ion diffusion model in internal channels. There are relatively few studies on water vapor environment simulation and equipment development based on water vapor parameter control, and there is no mature equipment for studying the degradation law of concrete performance under water vapor environment. Due to the limitation of the object to be tested, on-site non-destructive testing is generally used for structures except in special circumstances. For example, in the detection of concrete damage in already built bridges, core sampling for indoor testing is strictly prohibited. In addition, because water vapor damage is less severe than other forms of damage such as water damage and freeze-thaw damage, the data collection time span in the tracking observation of the on-site concrete structure condition is often measured in years. Long-term data collection is labor-intensive, time-consuming, and may also lead to misjudgment of patterns due to different collection equipment.

[0006] Therefore, it is very necessary to conduct long-term, high-precision water vapor environment simulation in the laboratory and improve the damage indicators of concrete structures under long-term water vapor damage, so as to further study the damage of concrete structures in water vapor environment. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a performance detection system for concrete structures in a water vapor environment, which can control and adjust the water vapor environment according to the feedback of the detection results to simulate the actual working conditions and thus complete the performance detection of the concrete structure; the purpose of the present invention is also to provide a performance detection method for concrete structures in a water vapor environment to achieve the above functions.

[0008] To achieve the above-mentioned purpose, the first aspect of the present invention provides a performance detection system for a concrete structure in a water vapor environment, which adopts the following technical solution: a performance detection system for a concrete structure in a water vapor environment, comprising:

[0009] a sample storage container having a storage cavity for storing the concrete sample;

[0010] A detection unit, used for detecting the concrete sample in the storage cavity;

[0011] A solution storage container, used for storing the solution;

[0012] a pumping pipeline connecting the solution storage container and the sample storage container, the pumping pipeline being provided with a delivery pump for pumping water vapor into the sample storage container, and a water vapor generating structure for forming water vapor being provided in the solution storage container or on the pumping pipeline;

[0013] The sample storage container is provided with an exhaust pipeline, and the exhaust pipeline is provided with a suction pump, and the suction pump is used to extract water vapor in the sample storage container;

[0014] The performance testing system also includes:

[0015] There are at least two liquid adding containers, at least one of which is a distilled water storage container for storing distilled water, and at least one of which is a chemical solution storage container for storing a chemical solution. A liquid adding pipeline is provided between each liquid adding container and the solution storage container, and a liquid adding pump is provided on the liquid adding pipeline. The liquid adding pump is used to pump the liquid in the corresponding liquid adding container into the solution storage container, so as to pump both the distilled water and the chemical solution into the solution storage container;

[0016] The control unit includes a humidity sensor for detecting the ambient humidity in the storage chamber and a detector for detecting the concentration of chemical solutes in the solution storage container. The control unit also includes a controller. The controller responds to the value of the humidity sensor to control the start of the suction pump and the delivery pump when the value of the humidity sensor is not equal to the set humidity value. The controller also responds to the value of the detector to control the start of the liquid addition pump corresponding to the chemical solution storage container when the value of the detector is lower than the set concentration value.

[0017] Beneficial effects: When in use, the distilled water in the distilled water storage container and the chemical solution in the chemical solution storage container are pumped into the solution storage container, the distilled water dilutes the chemical solution to obtain the required solution in the solution storage container, and the water vapor generating structure converts the solution into water vapor. When the humidity value detected by the humidity sensor is not equal to the set humidity value, the controller controls the suction pump and the delivery pump to start, and the water vapor in the storage chamber is extracted outward, and at the same time, water vapor is introduced into the storage chamber to replace the water vapor in the storage chamber, thereby changing the humidity value. When the concentration of the chemical solute in the solution storage container is less than the set concentration value, the liquid adding pump corresponding to the chemical solution storage container is started, and the concentration of the chemical solute in the solution storage container is adjusted by adding chemical solution to meet the requirements. The present invention has the following advantages:

[0018] 1. The water vapor environment is simulated realistically.

[0019] Through the solution storage container, liquid adding container, sample storage container and control unit, it is ensured that the water vapor environment of the concrete sample is close to the actual water vapor environment, and can automatically feedback and adjust.

[0020] 2. The error factors of water vapor environment are well controlled.

[0021] The water vapor in the storage chamber is replaced by the pumping pipeline and the exhaust pipeline, realizing a closed cycle, reducing or even completely eliminating the influence of the external environment on the water vapor environment in the sample storage container.

[0022] 3. High degree of automation.

[0023] By setting up a control unit, the suction pump and delivery pump are started and stopped according to the feedback from the humidity sensor, and the corresponding liquid addition pump is started and stopped according to the feedback from the detector, thereby achieving automatic adjustment of humidity and chemical solute concentration without manual intervention. The water vapor environment can be adjusted quickly and in real time according to actual conditions, making the water vapor environment closer to actual working conditions, ensuring long-term and uninterrupted detection, and realizing regular monitoring and automatic recording of data.

[0024] As a further improvement, the performance testing system includes a closed waste storage container connected to the exhaust line, and a suction pump is used to extract water vapor in the sample storage container into the waste storage container. The waste storage container ensures that the water vapor is not discharged to avoid polluting the environment.

[0025] As a further improvement, the sample storage container is a double-layer container, comprising an outer container and an inner container located within the outer container. The storage chamber is located within the inner container, and the pumping and exhaust lines pass through the outer and inner containers. The double-layer container further reduces the impact of the external environment on the storage chamber.

[0026] As a further improvement, at least two internal containers are provided, each of which is equipped with a corresponding pumping line and exhaust line. Providing at least two internal containers allows for comparative experiments and, because the internal containers have smaller volumes, allows for more accurate humidity sensor detection.

[0027] As a further improvement, at least two chemical solution storage containers are arranged, each chemical solution storage container is used to store a different chemical solution, at least two detectors are arranged correspondingly, and the controller responds to the values ​​of each detector simultaneously.

[0028] As a further improvement, the performance detection system includes a data acquisition instrument, which is connected to the detection unit, the humidity sensor, and the detector to collect data, and the controller is a computer connected to the data acquisition instrument.

[0029] As a further improvement, the performance detection system includes a display screen connected to the computer, and the display screen is used to display the detection data of the detection unit.

[0030] As a further improvement, the performance detection system includes a mounting bracket having an upper placement space and a lower placement space, the sample storage container is arranged in the upper placement space, and the solution storage container, liquid adding container, delivery pump, and liquid adding pump are arranged in the lower placement space.

[0031] A second aspect of the present invention provides a method for testing the performance of a concrete structure in a water vapor environment, which employs the following technical solutions: A method for testing the performance of a concrete structure in a water vapor environment, wherein a water vapor environment is established in a sample storage container to perform performance testing of a concrete sample, wherein establishing the water vapor environment comprises the following steps:

[0032] 1) detecting the humidity value in the sample storage container, and when the humidity value is not equal to the set humidity value, starting the suction pump to extract water vapor from the sample storage container and starting the delivery pump to deliver water vapor into the sample storage container;

[0033] 2) Detecting the concentration of the chemical solute in the solution storage container, and when the detected concentration value is less than the set concentration value, starting the liquid adding pump corresponding to the chemical solution storage container to add the chemical solution into the solution storage container.

[0034] Beneficial effects: During use, when the humidity value detected by the humidity sensor is not equal to the set humidity value, the suction pump and the delivery pump are started to extract the water vapor in the storage chamber and simultaneously introduce water vapor into the sample storage container to replace the water vapor in the storage chamber, thereby changing the humidity value. When the concentration of the chemical solute in the solution storage container is less than the set concentration value, the corresponding liquid addition pump is started to adjust the concentration of the chemical solute in the solution storage container by adding chemical solution to meet the requirements. The present invention has the following advantages:

[0035] 1. The water vapor environment is simulated realistically.

[0036] It ensures that the water vapor environment of the concrete sample is close to the actual water vapor environment, and it can automatically feedback and adjust.

[0037] 2. High degree of automation.

[0038] The suction pump and delivery pump are started and stopped according to the feedback of the humidity value in the sample storage container, and the corresponding liquid addition pump is started and stopped according to the feedback of the detector, thereby realizing automatic adjustment of humidity and chemical solute concentration without manual intervention. The water vapor environment can be adjusted quickly and in real time according to actual conditions, making the water vapor environment closer to the actual working conditions, ensuring long-term and uninterrupted detection, and realizing regular monitoring and automatic recording of data.

[0039] As a further improvement, in step 1), the water vapor in the sample storage container is sucked into a closed waste storage container by a suction pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other objects, features and advantages of the exemplary embodiments of the present application will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0041] Figure 1 This is a schematic diagram of the performance detection system for concrete structures in a water vapor environment according to the present invention;

[0042] Figure 2 is a three-dimensional diagram of the performance detection system of the concrete structure in the water vapor environment of the present invention;

[0043] Figure 3 is a rear view of the performance detection system for concrete structures in a water vapor environment according to the present invention;

[0044] Figure 4 This is a schematic diagram of the performance testing system for concrete structures in a water vapor environment of the present invention, with the outer box and the surrounding door removed;

[0045] Figure 5 This is a schematic diagram of the structure inside the internal container when the performance detection system for concrete structures in a water vapor environment of the present invention is used;

[0046] Figure 6 This is a diagram showing the measurement results of the volume change of a concrete sample in the first embodiment of the performance detection system for concrete structures in a water vapor environment of the present invention;

[0047] Figure 7 This is a graph showing the deterioration regularity of the mechanical properties of a concrete sample in a first embodiment of the performance detection system for a concrete structure under a water vapor environment of the present invention;

[0048] Figure 8 This is a diagram showing the measurement results of the volume change of a concrete sample in the second embodiment of the performance detection system for concrete structures in a water vapor environment of the present invention;

[0049] Figure 9 This is a diagram showing the degradation regularity of the mechanical properties of concrete samples in the second specific example of the performance detection system for concrete structures in a water vapor environment of the present invention.

[0050] Description of reference numerals:

[0051] 1. Inner container; 2. Storage chamber; 3. Concrete specimen; 4. Solution storage container; 5. Pumping pipeline; 6. Delivery pump; 7. Humidity sensor; 8. Data acquisition instrument; 9. Computer; 10. Liquid adding container; 11. Liquid adding pump; 12. Detector; 13. Waste storage container; 14. Suction pump; 15. Tension and pressure sensor; 16. Strain gauge; 17. Mounting bracket; 18. Outer box; 19. Outer box cover; 20. Lock; 21. Enclosure door; 22. Heat dissipation window; 23. Display screen; 24. Emergency stop switch; 25. Control switch; 26. Support base; 27. Hoop; 28. First displacement sensor; 29. ​​Second displacement sensor; 30. Mounting base; 31. Suspension part. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0053] Various non-limiting embodiments of the present invention are described in detail below. The number of any element in the drawings is for illustration only and not for limitation, and any name is only for distinction and does not have any limiting meaning.

[0054] The principles and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0055] Example 1 of the performance detection system for concrete structure in a water vapor environment provided by the present invention:

[0056] like Figures 1 to 9 As shown, the performance detection system for concrete structures in water vapor environment (hereinafter referred to as the performance detection system) simulates the real water vapor environment of concrete for a long time, performs performance detection in the water vapor environment, and performs automatic feedback and control.

[0057] like Figure 1 As shown, the principle of the performance testing system is first described. The performance testing system includes a sample storage container having a storage chamber 2 therein. The storage chamber 2 is used to store and hold a concrete sample 3 to be tested. The performance testing system also includes a testing unit that tests the concrete sample 3. The type of testing unit can be selected based on actual needs. The performance testing system also includes a solution storage container 4 that stores a solution. A humidifier is placed in the solution storage container 4 to convert the solution into water vapor and diffuse it into the solution storage container 4.

[0058] The performance testing system also includes a pumping line 5 connecting the sample storage container and the solution storage container 4. A delivery pump 6, typically an air pump, is disposed on the pumping line 5. The sample storage container is a double-layer container comprising an outer container and an inner container 1, with a storage chamber 2 formed within the inner container 1.

[0059] The performance testing system also includes three liquid adding containers 10, which are used to store distilled water, chloride solution and sulfate solution respectively. The three liquid adding containers 10 are connected to the solution storage container 4 through a liquid adding pipeline. A liquid adding pump 11 is arranged on the liquid adding pipeline. The liquid adding pump 11 is a liquid pump. The liquid adding pump 11 pumps the liquid in the liquid adding container 10 into the solution storage container 4. The liquids in the three liquid adding containers 10 are mixed in the solution storage container 4. The concentration of chloride and sulfate in the mixed solution must be the same as the concentration in the atmospheric environment. Among them, the concentrations of chloride solution and sulfate solution in the liquid adding container 10 are both relatively high, which is equivalent to dilution after mixing with distilled water.

[0060] The performance detection system also includes a waste storage container 13 . An exhaust pipeline is connected between the waste storage container 13 and the sample storage container. A suction pump 14 is arranged on the exhaust pipeline. The suction pump 14 can suck the water vapor in the storage chamber 2 into the waste storage container 13 .

[0061] The performance detection system further includes a control unit, which can automatically adjust the ambient humidity in the storage chamber 2 and the chloride concentration and sulfate concentration in the solution storage container 4 to meet the detection requirements.

[0062] The control unit includes a humidity sensor 7, which is placed in the storage chamber 2 to detect the ambient humidity within the storage chamber 2. The performance detection system also includes a detector 12, which is used to detect the concentrations of chloride and sulfate in the solution storage container 4. In this embodiment, there are two detectors 12, namely a chloride ion content meter and a portable sulfate ion detector. The detectors 12 are conventional. The control unit also includes a controller and a data acquisition device 8. The controller is a computer 9. The data acquisition device 8 is connected to the humidity sensor 7 and the detector 12. The data acquisition device 8 collects data from the humidity sensor 7 and the detector 12. The computer 9 is connected to the data acquisition device 8. The computer 9 compares the value of the humidity sensor 7 with the set humidity value and compares the value detected by the detector 12 with the set solute concentration value. The computer 9 is also connected to the delivery pump 6, the liquid adding pump 11, and the suction pump 14, and can control the start and stop of the delivery pump 6, the liquid adding pump 11, and the suction pump 14. The data acquisition device 8 is also connected to the control unit to collect data from the control unit.

[0063] Among them, the performance detection system includes a mounting bracket 17, which has upper and lower placement spaces. The sample storage container is installed in the upper placement space. The external container of the sample storage container includes an outer box body 18 fixed on the mounting bracket 17. The outer box body 18 is hinged with an outer box cover 19. A telescopic hydraulic rod (not shown in the figure) is installed between the outer box body 18 and the outer box cover 19. The telescopic hydraulic rod provides support when the outer box cover 19 is opened, while saving effort to avoid personal injury due to improper operation or sudden closure of the outer box cover 19 due to its excessive weight.

[0064] When the outer cover 19 is closed on the outer box body 18, it creates a sealed environment, preventing air exchange with the outside world and maintaining a constant humidity. Two latches 20 are installed on the outer box body 18, which lock the outer cover 19 securely. A sealing gasket is placed between the outer cover 19 and the outer box body 18. This gasket serves to cushion the closing force of the outer cover 19 during use, preventing damage to the cover 19 after prolonged use, and also provides a sealed environment.

[0065] The inner container 1 is placed in the outer box 18 , wherein there are two inner containers 1 side by side, which is convenient for comparative testing. Moreover, the space of the inner container 1 is small, which can improve the detection accuracy of the humidity sensor 7 .

[0066] Solution storage container 4 ( Figure 4 Not shown), three liquid adding containers 10 and waste storage container 13 ( Figure 4 Not shown) are placed in the lower storage space, the delivery pump 6, the liquid adding pump 11 ( Figure 4 Not shown), suction pump 14 ( Figure 4 The pumping line, liquid adding line, exhaust line and power lines of each pump are all arranged in the lower storage space.

[0067] Mounting bracket 17 is equipped with doors 21 on both the front and rear sides. Opening these doors allows access to the pumping lines, liquid filling lines, exhaust lines, and power cords for each pump. Heat dissipation windows 22 are installed on the sides of mounting bracket 17 to ensure air flow between the lower storage space and the external environment. The lower portion of these windows has a flush window, allowing for quick cleaning in the event of leakage or tipping during solution changes, preventing internal corrosion.

[0068] Computer 9 is placed in mounting bracket 17, located on one side of the upper and lower storage spaces. A display screen 23 is mounted on mounting bracket 17 and connected to computer 9. Test data can be directly displayed on display screen 23. An emergency stop switch 24 and a control switch 25 are mounted below display screen 23. A power supply assembly (obstructed and not visible) is housed within mounting bracket 17. Control switch 25 controls the opening and closing of valves on various pumps and pipelines.

[0069] In this embodiment, the detection unit includes an acoustic emission device, a shear and compression wave emission device, and a deformation measuring device. The acoustic emission device is placed in the middle of the concrete sample 3 to measure the development trend of cracks inside the concrete sample 3. The shear and compression wave emission device is placed at the top and bottom of the concrete sample 3 to measure the stiffness deterioration trend of the sample. The deformation measuring device measures the deformation of the concrete sample 3.

[0070] There is a pair of acoustic emission devices placed in the middle of the concrete sample 3. Specifically, the acoustic emission instrument is a RAE-M1 acoustic wave (acoustic emission) detector with an input bandwidth of 10kHz-100kHz and a digital filtering range of 0kHz-100kHz.

[0071] The shear and compression wave transmitter consists of a pair of combined bending and stretching element measurement devices, placed at the top and bottom of concrete specimen 3, respectively. The voltage range of the measuring chip in the combined bending and stretching element measurement device is 1-14V, and the acoustic wave transmission period is 1ms-0.01ms. Specifically, the combined bending and stretching element measurement device is model GDS-BE, with a measuring chip thickness of 1mm and a length of 2mm. The maximum axial bearing capacity is 2MPa, and the minimum measurement length of concrete specimen 3 is 30mm. It should be noted that both the acoustic transmitter and the shear and compression wave transmitter are mature testing products, and their installation and testing methods are based on existing technologies.

[0072] like Figure 1 and Figure 5 As shown, the deformation measurement device includes two strain gauges 16. The strain gauges 16 can detect a very small strain range. The strain gauges 16 are respectively attached to the middle of the concrete sample 3 in the horizontal and vertical directions. The strain of the concrete sample 3 can be detected through the strain gauges 16. Among them, the strain gauges 16 are KYOWA welding-free strain gauges with a measurement accuracy of 10 -6 , the measurement range is 10 -6 -10 -2 .

[0073] The deformation measuring device also includes two first displacement sensors 28 and two second displacement sensors 29. The first displacement sensors 28 and the second displacement sensors 29 are fixedly mounted on the bottom of the internal container 1 via a mounting base 30. The first displacement sensor 28 detects the longitudinal displacement of the set position of the concrete sample 3. Specifically, a hoop 27 is fixed to the outside of the concrete sample 3, and the first displacement sensor 28 is placed on the hoop 27. The second displacement sensor 29 detects the lateral displacement of the set position of the concrete sample 3. The first and second displacement sensors 28 and 29 are model GDS-L3D10, with a measurement accuracy of 1 micron, a range of 0-10 mm, and a temperature drift coefficient of less than 10. -2 mm / ℃, the overall length is less than 50mm.

[0074] A suspension member 31 is mounted on the side wall of the inner container 1. A support base 26 is suspended from the bottom of the suspension member 31 via a rope. Concrete specimen 3 is placed on support base 26. A tension and pressure sensor 15 is connected in series to the suspension member 31. This sensor can detect any signs of falling or fragmentation of the concrete specimen 3 in a water vapor environment.

[0075] like Figure 1 As shown, data acquisition device 8 is wired to the detection unit to collect detection data from the detection unit. Specifically, data acquisition device 8 includes a humidity data acquisition device, an acoustic emission data acquisition device, a deformation data acquisition device, and a bending element waveform data acquisition device. The humidity data acquisition device collects humidity data in the range of 0%-100%, the acoustic emission data acquisition device has a maximum acquisition frequency of 2kHz, the deformation data acquisition device includes a dynamic acquisition and temperature compensation module, and the bending element waveform data acquisition device has an acquisition voltage of 0-14V, an acquisition frequency of 1kHz-100kHz, and an acquisition duration of 0-10ms. Specifically, data acquisition device 8 is a TST5927 dynamic acquisition device with an acquisition frequency of 0.05kHz-100kHz, a temperature compensation module, and an A / D conversion module.

[0076] The use process of the present invention is as follows:

[0077] 1) Construct a relative humidity field as instructed by the control unit. Once the relative humidity field is constructed, the control unit can issue humidity change and adjustment instructions to establish a target humidity field within storage chamber 2. The humidity field monitoring value of storage chamber 2 is the relative humidity RH1 detected in real time by humidity sensor 7, and the relative humidity target value imported into the control unit is RH2. RH2 is a collection of humidity data that changes over time. This data set supports the import of large data, the import of underlying data from the input temperature field model, and manual input. All imported humidity field data is used by the control unit to control the relative humidity value of internal container 1.

[0078] 2) Calculate the chloride concentration in the solution storage container 4 and prepare the chloride solution in the liquid adding container 10 according to the mixing ratio with distilled water. Measure the chloride ion concentration in the gas environment of the concrete structure to be tested. The measurement result is the chloride concentration (W cl , mol / L).

[0079] 3) Calculate the sulfate concentration in the solution storage container 4 and prepare the sulfate solution in the liquid adding container 10 according to the mixing ratio with distilled water. The sulfate ion concentration in the atmosphere is measured by ion chromatography, and the measurement result is the sulfate concentration (W s , mol / L).

[0080] 4) Calibrate the data, place the concrete sample 3, and turn on the instrument. Check the imported humidity field data on the computer 9 for accuracy and the correct humidity values ​​within each cycle. Use a chloride ion content meter to check whether the chloride concentration in the solution storage container 4 meets the requirements. Use a portable sulfate ion detector to check whether the sulfate concentration in the solution storage container 4 meets the requirements.

[0081] 5) During the testing process, when RH1 ≠ RH2, computer 9 controls delivery pump 6 and suction pump 14 to start. Delivery pump 6 pumps water vapor from solution storage container 4 into storage chamber 2, while suction pump 14 simultaneously draws water vapor from storage chamber 2 into waste storage container 13 until RH1 equals RH2. When the chloride and / or sulfate concentrations in solution storage container 4 fall below a set concentration, computer 9 controls the corresponding liquid addition pump 11 to start, pumping chloride solution into solution storage container 4 until the chloride and sulfate concentrations reach the set concentrations.

[0082] The performance detection system of the present invention has the following technical advantages:

[0083] (1) There is almost no damage to the concrete structure, and non-destructive testing of the concrete structure can be achieved. That is, the mechanical properties of the concrete structure are not reduced. The internal strain of the concrete structure caused by the performance testing system is less than 10 -6 This strain is within the elastic range of most concrete materials, and the internal deformation caused is all recoverable deformation. There is no relative displacement or damage to the internal materials of the structure. Therefore, the present invention has almost no effect on the mechanical properties of the concrete structure.

[0084] (2) Effectively evaluate the long-term service performance of concrete structures. This invention can control the humidity of concrete structures in a conventional laboratory environment. Simultaneously, through the synchronous measurement of multiple sensing elements, it can intelligently monitor the long-term microscopic properties and macroscopic damage strain within the concrete, obtaining the degree of damage to the concrete structure in real time, thereby effectively evaluating the long-term service performance of the concrete structure.

[0085] (3) Effectively improve the maintenance efficiency of concrete structures. The humidity control and detection unit provided by the present invention has long-term stability and can obtain the damage patterns of concrete structures under long-term environmental changes. In particular, in an environment with high humidity differences, it can accurately measure the crack derivation patterns and stiffness degradation characteristics inside the concrete. Therefore, based on these patterns, the performance detection system of the present invention can better guide the maintenance cycle and measures of concrete structures in actual engineering, thereby greatly improving the maintenance efficiency.

[0086] A series of experiments were conducted based on the current performance testing system, and only two examples are introduced below.

[0087] 1. Monitoring process of concrete structure of a newly built bridge foundation. According to the needs, the bridge foundation is inspected at 4 locations, which includes the following steps:

[0088] (1) Determine the number, size, and mix ratio of molded concrete specimens and prepare the specimens: Based on engineering experience and indoor experimental design methods, the total experimental volume and the shortest operation time are comprehensively considered to determine the number of concrete specimens 3 to be prepared. In this embodiment, four locations of the bridge foundation are tested, and three parallel specimens are prepared at each location. In accordance with the specifications, a total of 12 standard cylindrical specimens with a diameter of 50 mm and a height of 100 mm are prepared. The concrete mix ratio of the specimens should be consistent with the mix ratio of the concrete material to be tested.

[0089] (2) Monitoring ambient humidity and constructing humidity field parameters: The ambient humidity value at the bridge foundation site is monitored long-term by humidity sensors installed during bridge foundation construction. The monitoring period is one year. After computer input and control system calculation, the humidity change period in the experiment is set to one month, for a total of 12 months. The humidity value within each cycle is the monthly average humidity monitored by the sensor. The error between the two values ​​is less than 5% after verification based on data collected from the China Meteorological Data Network. The humidity is set to the average value of the humidity monitored by the sensor. The relative humidity values ​​within the 12 cycles finally input into this system are shown in Table 1.

[0090] Table 1 Humidity values ​​for 12 cycles

[0091]

[0092] (3) Preparation and placement of salt solution: According to the test requirements, this scheme only studies the effect of chloride ions on water vapor damage. Referring to the steps mentioned above, calculate the chloride concentration in the solution storage container 4 and prepare the chloride solution. The experimental results show that the preparation of liquid V containing chloride ions is A =10 liters, calculate the concentration of the prepared chloride solution (W cl , mol / L) is: W cl =4.83*10 -4mol / L. The prepared chloride solution is pumped into the solution storage container 4 for use.

[0093] (4) After the specimen is cured, place the specimen and turn on the instrument. First, check whether the working indicators of the pumps, sensors, display screens, etc. are normally on. Secondly, import the humidity field data into the computer and check whether it is accurate. Set each humidity cycle period to 1 month, and the total cycle to 12 months. Use the salt solution and each pump to control humidity and salt ions. Work for 1 hour. Check whether the humidity sensor located in the internal container can transmit data normally and whether the data acquisition instrument can work normally.

[0094] (5) Construct a multi-index damage system to monitor the degradation of test specimens: The concrete specimen 3 was monitored for 360 days. The indicators that can be monitored simultaneously include strain, strength, damage cracks, shear modulus and axial modulus. Strain is measured by strain gauges 16 and displacement sensors. Figure 6 The results show that concrete sample 3 produced an irreversible volume change of 0.35% under 360d humidity cycle. The degradation rules of the four mechanical performance indicators, strength, damage cracks, shear modulus and axial modulus, were characterized by their respective normalized damage values, which were calculated as the ratio of the sensor monitoring value after the cycle to the initial value, as shown in the figure. Figure 7 Furthermore, the normalized damage values ​​of the four indicators of strength, damage cracks, shear modulus and axial modulus are the basic data of the degradation law function. After function fitting, the degradation law in the form of negative exponential is obtained:

[0095]

[0096] Where ξ0 is the damage variable, a and b are parameters, The damage strain.

[0097] This embodiment completes long-term monitoring of the ambient humidity of a bridge concrete foundation structure, simulates the water vapor environment with relatively high accuracy under indoor experimental conditions, improves the damage indicators of concrete structures under long-term water vapor damage, and obtains corresponding long-term degradation laws.

[0098] 2. Monitoring process of concrete load-bearing columns of a newly built house. According to the needs, the four positions of the load-bearing columns are tested, which specifically includes the following steps:

[0099] (1) Determine the monitoring point: Based on engineering experience, taking into account the total engineering volume and the shortest operation time, the structural material is sampled and a standard cylindrical sample with a diameter of 50 mm and a height of 100 mm is prepared in accordance with the specifications.

[0100] (2) Monitoring ambient humidity: The annual change in ambient humidity is 30%-90%. In the performance testing system provided by the present invention, corresponding humidity control is performed through salt solution and various pipelines and pumps, and each humidity cycle lasts for 3 months.

[0101] (3) Strain measurement: The performance detection system provided by the present invention has actually monitored the concrete sample 3 for 360 days. The strain gauge 16 and the displacement sensor have measured the structural strain. Figure 8 It can be seen that in this embodiment, concrete sample 3 produces an irreversible volume change of 0.52% under 360d humidity cycle.

[0102] (4) Determination of degradation law: The performance detection system provided by the present invention has carried out actual monitoring of concrete sample 3 for 360 days, and obtained the degradation law of various mechanical performance indicators as follows: Figure 9 Specifically, the degradation law in the form of negative exponential is obtained:

[0103]

[0104] Where ξ0 is the damage variable, a and b are parameters, The damage strain.

[0105] This embodiment completes the long-term monitoring of the environmental humidity of a concrete load-bearing column of a certain house and obtains the corresponding long-term degradation law, with good results.

[0106] In this embodiment, the humidifier in the solution storage container constitutes a vapor-generating structure capable of generating water vapor. In actual use, a fan can be added to the sample storage container. When turned on, the fan can disturb the gas in the storage chamber, making the water vapor diffuse evenly, thereby improving the detection accuracy of the humidity sensor. Of course, multiple humidity sensors can also be installed to provide feedback by taking an average value.

[0107] In this embodiment, the humidity sensor and detector are both connected to a data acquisition device. The computer collects and compares data from the data acquisition device, and then makes judgments and controls. In actual use, the humidity sensor itself can be preset to a set humidity value. In this case, the humidity sensor only transmits the comparison result to the controller, such as less than or equal to the set humidity value.

[0108] The liquid adding container storing distilled water is a distilled water storage container, and the container storing chloride solution and sulfate solution is a chemical solution storage container. In actual use, the type of chemical solution is changed according to experimental needs.

[0109] It should be noted that when the concentration of the chemical solute in the solution storage container is lower than the set concentration value, the liquid adding pump corresponding to the chemical solution storage container is turned on. Preferably, a liquid level gauge is added to the solution storage container, and the liquid adding pump is a metering pump, which can control the amount of solution added according to the difference between the actual concentration of the chemical solute in the solution storage container and the set concentration value.

[0110] The controller in this embodiment is a computer. In fact, the controller can also be a programmable single chip microcomputer or other structures.

[0111] Example 2 of the performance detection system for concrete structures in a water vapor environment provided by the present invention:

[0112] This embodiment differs from Example 1 primarily in that, in Example 1, the mounting bracket has an upper storage space and a lower storage space, with the sample storage container positioned in the upper storage space and the solution storage container, dosing pump, and other pumps positioned in the lower storage space. In this embodiment, the relative positions of the sample storage container, solution storage container, dosing pump, and other pumps can be varied, for example, such that the sample storage container, solution storage container, dosing pump, and other pumps are arranged sequentially on the same horizontal plane.

[0113] Example 3 of the performance detection system for concrete structures in a water vapor environment provided by the present invention:

[0114] The main difference between this embodiment and Example 1 is that there are three liquid adding containers in Example 1. In this embodiment, the number of liquid adding containers can be changed as needed, and there can be two or more than three liquid adding containers. Of course, the two liquid adding containers can also store the same type of solution.

[0115] Example 4 of the performance detection system for concrete structures in a water vapor environment provided by the present invention:

[0116] The main difference between this embodiment and Example 1 is that, in Example 1, the sample storage container is a double-layer container, comprising an outer container and an inner container, with two inner containers. In this embodiment, there is only one inner container. In other embodiments, the sample storage container is a single-layer container.

[0117] Example 5 of the performance detection system for concrete structures in a water vapor environment provided by the present invention:

[0118] The main difference between this embodiment and Example 1 is that, whereas in Example 1, the water vapor generating structure is a humidifier disposed in the solution storage container, this embodiment uses a sprayer disposed at the end of the pumping pipeline. The delivery pump here is a water pump that pumps the solution to the sprayer, which then generates water vapor in the storage chamber.

[0119] Embodiments of the method for detecting the performance of concrete structures in a water vapor environment provided by the present invention:

[0120] The performance testing method is consistent with the testing method in the performance testing system for concrete structures in the water vapor environment described above, and will not be described in detail here.

[0121] Although this specification has shown and described a number of embodiments of the present invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art will conceive of many modifications, changes, and alternatives without departing from the ideas and spirit of the present invention. It should be understood that in practicing the present invention, various alternatives to the embodiments of the present invention described herein may be employed. The appended claims are intended to define the scope of protection of the present invention and therefore cover modular compositions, equivalents, or alternatives within the scope of protection of these claims.

Claims

1. A performance detection system for concrete structures in a water vapor environment, characterized in that: include: a sample storage container having a storage cavity for storing the concrete sample; A detection unit, used for detecting the concrete sample in the storage cavity; A solution storage container, used for storing the solution; a pumping pipeline connecting the solution storage container and the sample storage container, the pumping pipeline being provided with a delivery pump for pumping water vapor into the sample storage container, and a water vapor generating structure for forming water vapor being provided in the solution storage container or on the pumping pipeline; The sample storage container is provided with an exhaust pipeline, and the exhaust pipeline is provided with a suction pump, and the suction pump is used to extract water vapor in the sample storage container; The performance testing system also includes: There are at least two liquid adding containers, at least one of which is a distilled water storage container for storing distilled water, and at least one of which is a chemical solution storage container for storing a chemical solution. A liquid adding pipeline is provided between each liquid adding container and the solution storage container, and a liquid adding pump is provided on the liquid adding pipeline. The liquid adding pump is used to pump the liquid in the corresponding liquid adding container into the solution storage container, so as to pump both the distilled water and the chemical solution into the solution storage container; A control unit, comprising a humidity sensor for detecting the ambient humidity in the storage chamber and a detector for detecting the concentration of a chemical solute in the solution storage container, the control unit also comprising a controller, the controller responsive to the value of the humidity sensor to control the start of a suction pump and a delivery pump when the value of the humidity sensor is not equal to a set humidity value, and the controller further responsive to the value of the detector to control the start of a liquid addition pump corresponding to the chemical solution storage container when the value of the detector is lower than a set concentration value; A closed waste storage container connected to an exhaust line, and a suction pump is used to extract water vapor in the sample storage container into the waste storage container.

2. The performance detection system for concrete structures in a water vapor environment according to claim 1 is characterized in that: The sample storage container is a double-layer container, which includes an outer container and an inner container located in the outer container. The storage cavity is formed in the inner container, and the pumping line and the exhaust line pass through the outer container and the inner container.

3. The performance detection system for concrete structures in a water vapor environment according to claim 2, characterized in that: There are at least two inner containers, and each inner container is provided with the corresponding pumping line and exhaust line.

4. The performance detection system for concrete structures in a water vapor environment according to claim 1, characterized in that: There are at least two chemical solution storage containers arranged, each chemical solution storage container is used to store a different chemical solution, and there are at least two detectors arranged accordingly, and the controller responds to the values ​​of each detector at the same time.

5. The performance detection system for concrete structures in a water vapor environment according to claim 1, characterized in that: The performance detection system comprises a data acquisition instrument, which is connected to the detection unit, the humidity sensor and the detector to collect data. The controller is a computer connected to the data acquisition instrument.

6. The performance detection system for concrete structures in a water vapor environment according to claim 5, characterized in that: The performance detection system includes a display screen connected to a computer, and the display screen is used to display detection data of the detection unit.

7. The performance detection system for concrete structures in a water vapor environment according to claim 1, characterized in that: The performance detection system includes a mounting bracket having an upper placement space and a lower placement space. The sample storage container is arranged in the upper placement space, and the solution storage container, liquid adding container, delivery pump, and liquid adding pump are arranged in the lower placement space.

Images