An experimental device and method for in-situ curing and testing of underwater concrete

Abstract

The application discloses an experimental device and method for in-situ maintenance and testing of underwater concrete, which comprises an experimental table, wherein the experimental table comprises a top platform and a bottom platform, the top platform is provided with a water pressure adjusting device, and the bottom platform is fixedly connected with an experimental cabin for simulating environmental parameters; the experimental cabin is filled with environmental water samples, and is provided with a temperature adjusting device and an injection device for supplementing the maintenance concrete; the bottom of the experimental cabin is further provided with a support table for the concrete samples to be tested; the water pressure adjusting device comprises a telescopic screw rod, a moving piston and a pressure sensor; the moving piston is telescopically arranged at the top opening of the experimental cabin to seal the experimental cabin; the telescopic screw rod is used for pushing and pulling the moving piston to change the water pressure in the experimental cabin; and the pressure sensor is arranged on the inner side wall of the experimental cabin. Through the creation of three in-situ conditions of pressure, temperature and water quality, the underwater concrete can be maintained and the performance detection can be carried out in a real in-situ environment.

Description

Technical Field

[0001] This invention relates to the field of concrete performance testing equipment, and in particular to experimental apparatus and methods for in-situ curing and testing underwater concrete. Background Technology

[0002] In recent years, the number of high dams built in my country has continued to increase. Due to factors such as environment, materials, and operating conditions, the concrete of hydropower station dams often suffers from defects such as erosion and cracks, causing leakage in the dam body. Dam leakage is one of the important factors affecting the safe operation of dams. Its main harm lies in reducing the durability of the dam and aggravating the formation of seepage channels in the dam body. If the defective parts are not repaired, the long-term seepage and erosion will gradually reduce the mechanical properties of the concrete dam and threaten the safe operation of the dam.

[0003] There are two common methods for dealing with dam defects and seepage: grouting within the gallery and underwater repair. Grouting within the gallery involves sealing the seepage defect by using cement or chemical grouting after the location of the defect has been determined. Underwater repair involves directly grouting the defective area after it has been observed underwater to repair it.

[0004] When repairing defects in underwater concrete structures, it is essential to first obtain the various properties of the underwater concrete used during underwater operations, including underwater setting time, mechanical properties, and bond properties. However, the performance of underwater concrete cured and tested under existing specifications can only provide a relative reference for actual projects and cannot represent the performance of underwater concrete cured and tested in a real underwater environment, thus failing to meet current engineering requirements. Therefore, to obtain the various performance indicators of concrete specimens cured in a real underwater environment, there is an urgent need for a concrete performance curing experimental device and method that can completely simulate the underwater environment of a dam. Summary of the Invention

[0005] To overcome the above problems, the present invention provides an experimental device and method for in-situ curing and testing of underwater concrete. By creating three in-situ conditions of pressure, temperature and water quality, underwater concrete can be cured and its performance tested in a near-real in-situ environment.

[0006] The technical solution adopted in this invention is:

[0007] An experimental apparatus for in-situ curing and testing of underwater concrete includes an experimental platform comprising a top platform and a bottom platform. A water pressure regulating device is installed on the top platform, and an experimental chamber for simulating environmental parameters is fixedly connected to the bottom platform. The experimental chamber contains a temperature regulating device and an injection device for replenishing the curing concrete. The concrete sample to be tested is placed at the bottom of the experimental chamber. The water pressure regulating device includes a telescopic screw, a moving piston, and a pressure sensor. The moving piston is telescopically positioned at the top opening of the experimental chamber, and the telescopic screw is fixed to the top platform for pushing and pulling the moving piston. The pressure sensor is located on the inner wall of the experimental chamber. By creating three in-situ conditions of pressure, temperature, and water quality, underwater concrete can be cured and its performance tested in a near-realistic in-situ environment.

[0008] Preferably, the injection device includes a sample chamber, a remote-controlled pressurizer, and an injection pipe. The sample chamber is used to hold the concrete sample. One end of the injection pipe is connected to the sample chamber, and the other end is set in the experimental chamber. The concrete sample is injected into the bottom of the experimental chamber by pressurizing through the remote-controlled pressurizer, thereby curing and testing the concrete sample.

[0009] Preferably, the temperature regulating device includes a temperature control rod and a temperature sensor for detecting the temperature of the experimental water sample in the experimental chamber. The temperature regulating device is installed on the side wall of the experimental chamber to regulate the water temperature so that it is consistent with the in-situ water temperature of the real environment.

[0010] Preferably, there are multiple temperature control rods, which are evenly distributed on the outer wall of the experimental chamber to make the temperature regulation more uniform.

[0011] Preferably, the side wall of the experimental chamber is evenly provided with multiple observation windows, which are arranged in an alternating manner to facilitate multi-angle observation of the curing status of the underwater concrete in the experimental chamber.

[0012] Preferably, the top platform and bottom platform of the experimental table are connected by multiple columns, and transparent explosion-proof glass is installed between adjacent columns.

[0013] Preferably, the surface of the moving piston and the inner wall of the experimental chamber are provided with a water-proof membrane.

[0014] An experimental method for in-situ curing and testing of underwater concrete is also provided, applied to the above-mentioned experimental apparatus, comprising the following steps:

[0015] S1: Take water samples on-site in the experimental environment, and transport the samples in a sealed container and store them at a constant temperature to ensure that the water quality remains unchanged.

[0016] S2: Arrange the concrete structure to be tested in the test chamber and add water sampled on site;

[0017] S3: Adjust the temperature of the experimental chamber to the underwater ambient temperature, use an underwater temperature sensor to measure the water temperature in the experimental chamber, and adjust the temperature control rod if there is a deviation. Through the principle of heat transfer, make the water temperature in the experimental chamber reach the initial water temperature of the underwater depth of the project.

[0018] S4: Adjust the pressure in the experimental chamber by manipulating the moving piston through the telescopic screw to reach the preset value;

[0019] S5: By injecting concrete into the sample chamber, in-situ environmental curing of the underwater concrete structure is achieved. The apparent changes during the underwater concrete curing process are observed through the observation window, thereby conducting performance tests on the underwater concrete and detecting the parameters of the concrete structure.

[0020] The beneficial effects of this invention are:

[0021] This invention employs an experimental apparatus and method for in-situ curing and testing of underwater concrete. The apparatus includes an experimental platform comprising a top platform and a bottom platform. A water pressure regulating device is installed on the top platform, and an experimental chamber for simulating environmental parameters is fixedly connected to the bottom platform. The experimental chamber contains a temperature regulating device and an injection device for replenishing the curing concrete. The concrete sample to be tested is placed at the bottom of the experimental chamber. The water pressure regulating device includes a telescopic screw, a moving piston, and a pressure sensor. The moving piston is telescopically positioned at the top opening of the experimental chamber, and the telescopic screw is fixed to the top platform for pushing and pulling the moving piston. The pressure sensor is located on the inner wall of the experimental chamber. By creating three in-situ conditions—pressure, temperature, and water quality—underwater concrete can be cured and its performance tested in a near-realistic in-situ environment. Attached Figure Description

[0022] Figure 1 This is an overall structural diagram of the present invention;

[0023] Figure 2 This is a structural diagram of the experimental platform of the present invention;

[0024] Figure 3 This is a structural diagram of the experimental chamber of the present invention;

[0025] Figure 4 This is a structural diagram of the injection device of the present invention.

[0026] Detailed explanation of element symbols:

[0027] 1-Experimental platform, 2-Water pressure regulating device, 3-Injection device, 4-Experimental chamber, 5-Temperature regulating device, 6-Concrete sample, 11-Column, 12-Top platform, 13-Bottom platform, 14-Transparent explosion-proof glass, 21-Moving piston, 22-Telescopic screw, 23-Pressure sensor, 31-Sample chamber, 32-Remote pressurizer, 33-Injection pipe, 41-Observation window, 51-Temperature sensor. Detailed Implementation

[0028] The present solution will now be described in conjunction with the accompanying drawings and specific embodiments.

[0029] Example 1: Please refer to Figures 1 to 4 This embodiment discloses an experimental apparatus for in-situ curing and testing of underwater concrete, comprising an experimental platform 1, which includes a top platform 12 and a bottom platform 13. A water pressure regulating device 2 is installed on the top platform 12, and an experimental chamber 4 for simulating environmental parameters is fixedly connected to the bottom platform 13. The experimental chamber 4 is equipped with a temperature regulating device 5 and an injection device 3 for replenishing concrete. A concrete sample 6 to be tested is placed at the bottom of the experimental chamber 4. The water pressure regulating device 2 includes a telescopic screw 22, a moving piston 21, and a pressure sensor 23. The moving piston 21 is telescopically mounted at the top opening of the experimental chamber 4, the telescopic screw 22 is used to push and pull the moving piston 21, and the pressure sensor 23 is mounted on the inner wall of the experimental chamber 4. By creating three in-situ conditions of pressure, temperature, and water quality, underwater concrete can be cured and its performance tested in a near-real in-situ environment.

[0030] Example 2: Please refer to Figure 1 and Figure 4 The injection device 3 in this embodiment includes a sample chamber 31, a remote-controlled pressurizer 32, and an injection pipe 33. The sample chamber 31 is used to hold the concrete sample 6. One end of the injection pipe 33 is connected to the sample chamber 31, and the other end is placed in the experimental chamber 4. The concrete sample is injected into the bottom of the experimental chamber 4 by pressurizing through the remote-controlled pressurizer 32, thereby curing and testing the concrete sample. The temperature regulation device 5 in this embodiment includes a temperature control rod and a temperature sensor 51 for detecting the temperature of the experimental water sample in the experimental chamber 4. The temperature regulation device 5 is set on the side wall of the experimental chamber 4 to regulate the water temperature and keep it consistent with the in-situ water temperature of the real environment. In this embodiment, there are multiple temperature control rods, which are evenly distributed on the outer wall of the experimental chamber 4 to make the temperature regulation more uniform.

[0031] Example 3: Please refer to Figure 2 and Figure 3In this embodiment, the experimental chamber 4 has multiple observation windows 41 evenly arranged on its side walls. These windows are staggered to facilitate multi-angle observation of the underwater concrete curing process within the experimental chamber 4. In this embodiment, the top platform 12 and bottom platform 13 of the experimental table 1 are connected by multiple columns 11, with transparent explosion-proof glass 14 positioned between adjacent columns 11. In this embodiment, the surface of the moving piston 21 and the inner wall of the experimental chamber 4 are covered with a waterproof membrane.

[0032] Example 4: Please refer to Figures 1 to 4 This embodiment also provides an experimental method for in-situ curing and testing of underwater concrete, applied to the above-mentioned experimental apparatus, including the following steps: S1: taking on-site samples of water in the experimental environment, and transporting the obtained samples in a sealed manner and storing them at a constant temperature to ensure that the water quality remains unchanged; S2: arranging the concrete structure to be tested in the experimental chamber 4, and adding the on-site sampled water.

[0033] S3: Adjust the temperature of experimental chamber 4 to the underwater ambient temperature. Use underwater temperature sensor 51 to measure the water temperature in experimental chamber 4. If there is a deviation, adjust the temperature control rod. Through the principle of heat transfer, make the water temperature in experimental chamber 4 reach the initial water temperature of the underwater depth required for this project. S4: Use telescopic screw 22 to operate moving piston 21 to adjust the pressure in experimental chamber 4 to reach the preset value. S5: Inject concrete through sample chamber 31 to achieve in-situ environmental curing of the underwater concrete structure being tested. Observe the apparent changes of the underwater concrete curing process through observation window 41, and then conduct performance tests on the underwater concrete and detect the parameters of the concrete structure.

[0034] Example 5: Please refer to Figure 1 and Figure 2The experimental platform 1 consists of two layers, each with a 3cm thick hexagonal surface and a side length of 0.7m. Six 10cm diameter columns 11 connect the upper and lower layers. Both the experimental platform 1 and the columns 11 are made of stainless steel. The bottom platform 13 houses and is fixedly connected to the experimental chamber 4. The top platform 12 serves as the working platform for the water pressure regulating device 2, and the movement of the moving piston 21 within the experimental chamber 4 is controlled by a stainless steel telescopic screw 22. Transparent explosion-proof glass 14 is embedded in the facade between the six columns 11. The experimental chamber 4 is cylindrical, with its bottom plate and side walls integrated. It has an open top and houses the experimental water and a concrete sample injection device 3 submerged in the water. The upper part of the experimental water is sealed by the moving piston 21 of the water pressure regulating device 2, with a waterproof membrane adhered to the surface of the piston 21. The function of the experimental chamber 4 is to hold an appropriate amount of on-site sampled water, creating a high-pressure experimental environment under the action of the water pressure regulating device 2. The main body of Experiment Chamber 4 is made of stainless steel alloy with low density and high compressive strength, with an inner diameter of 0.4m, a height of 2.0m, and a wall thickness of 1.0cm. Two rows of eight observation windows 41, each measuring 5cm × 8cm (width × height), are evenly arranged along the perimeter of Experiment Chamber 4 at heights of 0.2m and 0.5m from the bottom upwards. To facilitate multi-angle observation of the underwater concrete curing process within Experiment Chamber 4, the two rows of observation windows 41 are staggered.

[0035] The water pressure regulating device 2 consists of a telescopic screw 22, a motor, a moving piston 21, and a pressure sensor 23, creating an in-situ pressure environment. The telescopic screw 22 and motor are fixed to the top platform 12. The motor provides power, driving the telescopic screw 22 to rotate in both directions, which in turn drives the moving piston 21 to reciprocate, thus applying different pressures to the water surface to meet different experimental conditions. The pressure sensor 23 is positioned on the side wall of the experimental chamber 4, 0.35m above the bottom, to monitor the underwater pressure in real time. The temperature regulating device 5 consists of temperature control rods and a temperature sensor 51. Four temperature control rods, each 1m long and 0.1m wide, are evenly fixed around the perimeter of the experimental chamber 4 to ensure that the temperature of the experimental water sample in the chamber is the same as the actual underwater ambient temperature, creating an in-situ temperature environment. The temperature sensor 51 is positioned on the side wall of the experimental chamber 4, 0.30m above the bottom, to monitor the underwater temperature in real time. In addition, water is added to the experimental chamber 4 on-site to maintain the in-situ water quality environment, creating an underwater environment as close as possible to reality, thereby ensuring that the underwater concrete can be cured and its performance tested in situ. The underwater concrete injection device 3 consists of three parts: a sample chamber 31, a remote-controlled pressurizer 32, and a spray pipe 33. The sample chamber 31 is cylindrical, 0.4m high and 0.2m in diameter, and contains an underwater concrete sample 6. The sample chamber 31 is controlled by the remote-controlled pressurizer 32 to spray the concrete sample 6. Since the sample chamber 31 and the underwater concrete are under the same pressure underwater, the sample chamber 31 only needs to provide the conventional grouting pressure. The main body of the sample chamber 31 is made of stainless steel alloy and is fixed to the inner wall of the right side of the experimental chamber 4. The bottom is located 1.5m above the bottom of the side wall of the experimental chamber 4. The spray pipe has a diameter of 8cm and is connected to the bottom of the sample chamber 31 to inject the concrete sample 6 into the experimental chamber 4. The built-in concrete injection device 3 can spray concrete directly into the ambient water or into the mold in this high-pressure environment.

[0036] Example 6: Please refer to Figure 1 and Figure 2 In this embodiment, the hydropower station dam is a concrete gravity dam with a height of 200m. Due to factors such as erosion and aging, defects have appeared on the concrete surface at the bottom of the dam. In order to ensure the safe operation of the dam, the defective parts need to be repaired. It is necessary to determine the strength of the underwater concrete at different curing periods in this working environment. The present invention is used to conduct curing and testing experiments on the underwater concrete required for the dam.

[0037] Before the experiment, water was collected from the site, transported in a sealed container, and stored at a constant temperature to ensure its quality remained unchanged. The collected water was then added to experimental chamber 4. The temperature of experimental chamber 4 was adjusted to the underwater ambient temperature. An underwater temperature sensor 51 was used to measure the water temperature in experimental chamber 4. If there was a deviation, the temperature control rod was adjusted. Through the principle of heat transfer, the water temperature in experimental chamber 4 was brought to the initial water temperature required for that underwater depth in the project. This section of the dam was subjected to hydrostatic pressure, with a pressure of 1962 kPa at the bottom. Experimental chamber 4 had a diameter of 0.4 m, and the water pressure regulating device 2 needed to provide a pressure of 246.43 kN. The moving piston 21 of the water pressure regulating device 2 was manipulated to contact the water surface, and then the pressure was slowly increased to 246.43 kN. At this point, the in-situ conditions for water quality, temperature, and pressure were established, and the experimental environment closely resembled the actual underwater environment at the bottom of the dam. This allowed for in-situ environmental curing of underwater concrete. The apparent changes during the underwater concrete curing process could be observed through the observation window 41, enabling underwater concrete performance testing.

[0038] The advantages of this invention are:

[0039] 1) By creating an environment with in-situ pressure, actual temperature, and original water quality for underwater concrete, underwater concrete can be cured and its performance tested in a near-real "in-situ" environment.

[0040] 2) The underwater concrete performance "in-situ" curing test equipment designed in this invention can create a real working environment close to that of each actual project by adjusting factors such as pressure, temperature and water quality, for actual projects in different regions and with different dam heights, and has universality.

[0041] 3) Although this invention is designed as an "in-situ" curing experimental device for testing the performance of underwater concrete, it can be applied to other materials that require performance testing under certain pressure, temperature and water quality conditions by modifying parameters or adding other devices.

[0042] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the present invention is not limited thereto. Any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention, and all of the above should be within the protection scope of this patent.

Claims

1. An experimental apparatus for in-situ curing and testing of underwater concrete, characterized in that, The test includes an experimental platform (1), which includes a top platform (12) and a bottom platform (13). A water pressure regulating device (2) is installed on the top platform (12), and an experimental chamber (4) for simulating environmental parameters is fixed on the bottom platform (13). A temperature regulating device (5) and an injection device (3) for replenishing concrete are installed inside the experimental chamber (4). A concrete sample (6) to be tested is placed at the bottom of the experimental chamber (4). The water pressure regulating device (2) includes a telescopic screw (22), a moving piston (21), and a pressure sensor (23). The moving piston (21) is telescopically installed at the top opening of the experimental chamber (4). The telescopic screw (22) is fixed on the top platform (12) and is used to push and pull the moving piston (21) to increase or decrease the water pressure. The pressure sensor (23) is installed on the inner wall of the experimental chamber (4). The injection device (3) includes a sample chamber (31), a remote pressurizer (32) and an injection pipe (33). The sample chamber (31) is used to hold a concrete sample (6). One end of the injection pipe (33) is connected to the sample chamber (31), and the other end is set in the experimental chamber. The concrete sample is injected into the experimental chamber (4) by pressurizing through the remote pressurizer (32). The temperature regulating device (5) includes a temperature control rod and a temperature sensor (51) for detecting the temperature of the experimental water sample in the experimental chamber (4). The temperature regulating device (5) is installed on the side wall of the experimental chamber (4). The number of temperature control rods is multiple, and they are evenly distributed on the outer wall of the experimental chamber (4); The experimental chamber (4) has multiple observation windows (41) evenly arranged on its side wall, and the multiple observation windows (41) are staggered. The top platform (12) and bottom platform (13) of the experimental table (1) are connected by multiple columns (11), and transparent explosion-proof glass (14) is provided between adjacent columns (11); The surface of the movable piston (21) and the inner wall of the experimental chamber (4) are provided with a water-proof membrane.

2. An experimental method for in-situ curing and testing of underwater concrete, characterized in that, Applied to the experimental apparatus of claim 1, Includes the following steps: S1: Take water samples on-site in the experimental environment, and transport the samples in a sealed container and store them at a constant temperature to ensure that the water quality remains unchanged. S2: Arrange the concrete structure to be tested in the experimental chamber (4) and add water sampled on site; S3: Adjust the temperature of the experimental chamber (4) to the underwater ambient temperature, use the underwater temperature sensor (51) to measure the water temperature in the experimental chamber (4), and adjust the temperature control rod if there is a deviation. Through the principle of heat transfer, make the water temperature in the experimental chamber (4) reach the initial water temperature of the underwater depth of the project. S4: The pressure in the experimental chamber (4) is adjusted by manipulating the moving piston (21) through the telescopic screw (22) to reach the preset value; S5: By injecting concrete into the sample chamber (31), the underwater concrete structure under test is cured in situ. The apparent changes of the underwater concrete curing process are observed through the observation window (41), and the performance of the underwater concrete is tested and the parameters of the concrete structure are detected.

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