Device and method for quantitatively evaluating permeability performance of cracked concrete after repair

Abstract

The present invention discloses a device and method for quantitatively evaluating the permeability performance of cracked concrete after repair. The device includes a constant-pressure air pump, a pressurized water tank, a water inlet box, a water outlet box, a limiting mechanism, and a water storage tank; the water inlet box and the water outlet box are relatively arranged on both sides of the concrete specimen to be tested, and the limiting mechanism is used to fixedly limit the water inlet box, the concrete specimen, and the water outlet box; the pressurized water tank is connected to the water inlet box, the water storage tank is connected to the water outlet box, and the water storage tank is connected to the pressurized water tank through a return pipe; the constant-pressure air pump is connected to the pressurized water tank or the water storage tank. The present invention uses the water head difference between the pressurized water tank and the water storage tank within a specified time or the time required for the pressurized water tank and the water storage tank to reach a specified water head difference as the performance evaluation parameter. By measuring the value of the performance evaluation parameter and calculating, the permeability performance of cracked concrete after repair is quantitatively evaluated. The single test time is short, the test efficiency is high, the test results are accurate and reliable, and there is no need to replenish water after each test, saving water resources.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete material testing, and particularly relates to a device and method for quantitatively evaluating the permeability of cracked concrete after repair. Background Technique

[0002] In recent years, with the booming development of China's marine economy, various infrastructure facilities have been continuously developed towards the open sea and deep sea. Due to the high deep-sea pressure and strong seawater corrosiveness, some diseases have begun to appear in deep-sea concrete. For facilities such as submarine immersed tubes, if cracks occur in the concrete and then leakage occurs, the consequences will be unthinkable. Therefore, we need to repair the concrete when micro-cracks appear on its surface to prevent the cracks from further developing. Thus, it is particularly urgent to develop a device and method that can simulate the deep-sea environment and test the permeability of concrete before and after repair.

[0003] Currently, there are many devices and methods for testing the permeability of concrete specimens, but they all have many drawbacks, resulting in low test efficiency or inaccurate test results. For example: (1) During the penetration process, the water head difference between the two water tanks will tend to zero, resulting in a decreasing seepage velocity, a long test cycle for each test, and low test efficiency, which cannot meet the requirement of testing multiple concrete specimens in a short time; (2) The existing devices do not have equipment to control the air pressure in the pressurized water tank and the water storage tank to be constant, making the current test method have a large error in measuring the permeability parameters, and further resulting in a large deviation in the evaluation of the specimen's permeability; (3) The existing method evaluates the permeability of cracked concrete after repair by obtaining the seepage velocity, with a complex formula and cumbersome calculation. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a device and method for quantitatively evaluating the permeability of cracked concrete after repair, with a short single test time, high test efficiency, accurate and reliable test results, and no need to replenish water after each test, saving water resources.

[0005] The present invention provides the following technical solutions:

[0006] In the first aspect, a device for quantitatively evaluating the permeability of cracked concrete after repair is provided, including a constant-pressure air pump, a pressurized water tank, a water inlet box, a water outlet box, a limiting mechanism, and a water storage tank;

[0007] The water inlet box and the water outlet box are relatively arranged on both sides of the concrete specimen to be tested, and the limiting mechanism is used to fix and limit the water inlet box, the concrete specimen, and the water outlet box;

[0008] The pressurized water tank is connected to the water inlet box, the water storage tank is connected to the water outlet box, and the water storage tank is connected to the pressurized water tank through a return pipe;

[0009] The constant-pressure air pump is connected to the pressurized water tank or the water storage tank.

[0010] Further, both the water inlet box and the water outlet box are boxes with an opening on one side, and a sealing rubber ring is provided at the edge of the opening side.

[0011] Further, the limiting mechanism includes a first limiting plate, a second limiting plate, a guide rail and a threaded rod. The first limiting plate and the second limiting plate are arranged opposite to each other. The guide rail slidably penetrates through the first limiting plate and the second limiting plate. The threaded rod penetrates through the first limiting plate and the second limiting plate, and a locking nut for adjusting the positions of the first limiting plate and the second limiting plate is sleeved outside the threaded rod.

[0012] Further, a pressure gauge and a first air inlet pipe are provided at the top of the pressurized water tank. A first air valve is provided on the first air inlet pipe, and a first transparent scale is provided on the pressurized water tank.

[0013] Further, a second air inlet pipe is provided at the top of the water storage tank. A second air valve is provided on the second air inlet pipe, and a second transparent scale is provided on the water storage tank.

[0014] Further, the bottom of the pressurized water tank is connected to the water inlet box through a water inlet pipe. A flow velocity sensor is provided on the water inlet pipe. A first water valve is provided at the connection between the pressurized water tank and the water inlet pipe, and a first return valve is provided at the connection between the pressurized water tank and the return pipe.

[0015] Further, the bottom of the water storage tank is connected to the water outlet box through a water outlet pipe. A second water valve is provided at the connection between the water storage tank and the water outlet pipe, and a second return valve is provided at the connection between the water storage tank and the return pipe.

[0016] In a second aspect, a method for quantitatively evaluating the permeability performance of cracked concrete after repair by using the device described in the first aspect is provided, including the following steps:

[0017] Place the water inlet box and the water outlet box on both sides of the cracked concrete specimen, ensure that the water inlet box and the water outlet box completely cover the crack, and then fix the water inlet box, the concrete specimen and the water outlet box through the limiting mechanism;

[0018] Close the return pipe. Connect the constant-pressure air pump to the pressurized water tank. Calculate the seepage pressure according to the underwater service depth of the concrete specimen, and set the air pressure of the constant-pressure air pump to the seepage pressure;

[0019] Open the pressurized water tank, so that the water in the pressurized water tank enters the water storage tank after passing through the water inlet box, the cracked concrete specimen and the water outlet box. Take the water head difference between the pressurized water tank and the water storage tank within a specified time or the time required for the pressurized water tank and the water storage tank to reach a specified water head difference as the performance evaluation parameter, and record the numerical value of the performance evaluation parameter;

[0020] After the recording is completed, open the reflux pipe, connect the constant-pressure air pump to the water storage tank, and let the water in the water storage tank enter the pressurized water tank through the reflux pipe until the water heads of the pressurized water tank and the water storage tank return to the original height;

[0021] Repair the cracked concrete specimen. After the repair is completed, use the aforementioned method to test the cracked area and the uncracked area of the concrete specimen after repair, and record the numerical values of the performance evaluation parameters;

[0022] Quantitatively evaluate the repair effect of the cracked concrete specimen based on the measured numerical values of the performance evaluation parameters.

[0023] Further, the performance evaluation parameter is the water head difference between the pressurized water tank and the water storage tank within a specified time. The calculation formula for quantitative evaluation based on this performance evaluation parameter is:

[0024]

[0025] In the formula, x t is the repair index calculated for the fixed time t, and Δh1, Δh2, and Δh3 are the water head differences between the pressurized water tank and the water storage tank measured in the cracked area, the cracked area after repair, and the uncracked area of the concrete specimen within the specified time t, respectively.

[0026] Further, the performance evaluation parameter is the time required for the pressurized water tank and the water storage tank to reach a specified water head difference. The calculation formula for quantitative evaluation based on this performance evaluation parameter is:

[0027]

[0028] In the formula, x h is the repair index calculated for the fixed water head difference h, and Δt1, Δt2, and Δt3 are the times required for the cracked area, the cracked area after repair, and the uncracked area of the concrete specimen to reach the specified water head difference h between the pressurized water tank and the water storage tank, respectively.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] (1) The present invention connects a constant-pressure air pump to the pressurized water tank, calculates the seepage pressure according to the underwater service depth of the concrete specimen, and sets the air pressure of the constant-pressure air pump as the seepage pressure, which can simulate the deep-sea environment, maintain the air pressure of the pressurized water tank unchanged, improve the accuracy of the test results, and at the same time, avoid the reduction of the seepage velocity caused by the gradual decrease of the water head difference between the pressurized water tank and the water storage tank, which helps to improve the test efficiency and shorten the test time;

[0031] (2) The performance evaluation parameter of the present invention is the head difference between the pressurized water tank and the water storage tank within a specified time or the time required for the pressurized water tank and the water storage tank to reach a specified head difference. It quantitatively evaluates the permeability of the repaired cracked concrete, without the need for cumbersome formula calculations, avoiding the influence of the deterioration of the material itself's performance after long-term service of the concrete raw materials on the decrease in permeability, and overcoming the error of only using the seepage velocity to evaluate the seepage performance in the traditional method.

[0032] (3) The water storage tank of the present invention is connected to the pressurized water tank through a return pipe. After the numerical record of the performance evaluation parameter is completed, the return pipe is opened, and the constant pressure air pump is connected to the water storage tank, so that the water in the water storage tank enters the pressurized water tank through the return pipe until the original head height of the pressurized water tank and the water storage tank is restored, realizing the recycling of the test water. There is no need to inject water into the pressurized water tank after each test, saving water resources. Description of the Drawings

[0033] Figure 1 is a schematic structural view of the device for quantitatively evaluating the permeability of the repaired cracked concrete in the embodiment of the present invention;

[0034] Figure 2 is a schematic structural view of the limiting mechanism in the embodiment of the present invention;

[0035] Figure 3 is a schematic structural view of the device for quantitatively evaluating the permeability of the repaired cracked concrete without installing a concrete specimen in the embodiment of the present invention;

[0036] The labels in the figure are: 1, constant pressure air pump; 2, pressurized water tank; 3, water storage tank; 4, limiting mechanism; 401, first limiting plate; 402, second limiting plate; 403, threaded rod; 404, locking nut; 405, guide rail; 5, concrete specimen; 6, water inlet box; 7, water outlet box; 8, first air valve; 9, pressure gauge; 10, first transparent scale; 11, return pipe; 12, first return valve; 13, second return valve; 14, water inlet pipe; 15, first water valve; 16, flow velocity sensor; 17, water outlet pipe; 18, second water valve; 19, second air inlet pipe; 20, second air valve; 21, second transparent scale; 22, first air inlet pipe. Detailed Embodiments

[0037] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0038] It should be noted that in the description of the present invention, the orientation or positional relationship indicated by the terms "front", "rear", "left", "right", "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0039] Embodiment 1

[0040] As Figure 1 shown, this embodiment provides a device for quantitatively evaluating the permeability of cracked concrete after repair, including a constant-pressure air pump 1, a pressurized water tank 2, a water inlet box 6, a water outlet box 7, a limiting mechanism 4, and a water storage tank 3.

[0041] As Figure 1 shown, the materials of the water inlet box 6 and the water outlet box 7 can be selected as aluminum, and both are box bodies with an opening on one side, and a sealing rubber ring is provided at the edge of the opening side. The water inlet box 6 and the water outlet box 7 are oppositely arranged on both sides of the concrete specimen 5 to be tested, and the sealing rubber ring is used to ensure that the water flowing through the water inlet box 6, the concrete specimen 5, and the water outlet box 7 will not leak.

[0042] As Figure 1 and Figure 2 shown, the material of the limiting mechanism 4 can be selected as steel, and it has a large enough space to place concrete specimens of different sizes, with universality. The limiting mechanism 4 includes a first limiting plate 401, a second limiting plate 402, a guide rail 405, and a threaded rod 403; the first limiting plate 401 and the second limiting plate 402 are oppositely arranged and can be set in any shape such as rectangular or circular. In this embodiment, it is rectangular; the guide rail 405 slidably penetrates through the first limiting plate 401 and the second limiting plate 402, and the guide rail 405 is uniformly distributed at the edges of the first limiting plate 401 and the second limiting plate 402 to improve the stability of the relative movement of the two. In this embodiment, 4 guide rails 405 are respectively arranged at the four corners of the first limiting plate 401 and the second limiting plate 402; the threaded rod 403 penetrates through the upper and lower parts of the first limiting plate 401 and the second limiting plate 402, and a locking nut 404 for adjusting the positions of the first limiting plate 401 and the second limiting plate 402 is sleeved outside the threaded rod 403. Place the water inlet box 6, the concrete specimen 5, and the water outlet box 7 between the first limiting plate 401 and the second limiting plate 402, rotate the locking nut 404, adjust the relative movement of the first limiting plate 401 and the second limiting plate 402 and press them tightly on the surfaces of the water inlet box 6 and the water outlet box 7, so as to realize the fixed limit of the limiting mechanism on the water inlet box 6, the concrete specimen 5, and the water outlet box 7.

[0043] As Figure 1 and Figure 3As shown, the height of the pressurized water tank 2 is 1.5 m. A pressure gauge 9 and a first air inlet pipe 22 are provided at the top of the pressurized water tank 2. A first air valve 8 is provided on the first air inlet pipe 22. A 300-mm first transparent scale 10 is provided on the body of the pressurized water tank 2, facilitating the observation of the change in the water head height inside the pressurized water tank 2.

[0044] As Figure 1 and Figure 3 shown, the height of the water storage tank 3 is 1.5 m. A second air inlet pipe 19 is provided at the top of the water storage tank 3. A second air valve 20 is provided on the second air inlet pipe 19. A 300-mm second transparent scale 21 is provided on the water storage tank 3, facilitating the observation of the change in the water head height inside the water storage tank 3.

[0045] As Figure 1 and Figure 3 shown, the constant pressure air pump 1 is connected to the first air inlet pipe 22 of the pressurized water tank 2 or the second air inlet pipe 19 of the water storage tank 3. The bottom of the pressurized water tank 2 is connected to the water inlet box 6 through a water inlet pipe 14. A flow velocity sensor 16 is provided on the water inlet pipe 14. A first water valve 15 is provided at the connection between the pressurized water tank 2 and the water inlet pipe 14. The bottom of the water storage tank 3 is connected to the water outlet box 7 through a water outlet pipe 17. A second water valve 18 is provided at the connection between the water storage tank 3 and the water outlet pipe 17. The water storage tank 3 is connected to the pressurized water tank 2 through a return pipe 11. A first return valve 12 is provided at the connection between the pressurized water tank 2 and the return pipe 11. A second return valve 13 is provided at the connection between the water storage tank 3 and the return pipe 11.

[0046] Embodiment 2

[0047] This embodiment provides a method for quantitatively evaluating the permeability performance of repaired cracked concrete by using the device described in Embodiment 1, including the following steps:

[0048] (1) Place the water inlet box 6 and the water outlet box 7 on both sides of the cracked concrete specimen 5, keeping the cracked surface of the concrete specimen 5 perpendicular to the ground to reduce the influence of gravity on the test, and at the same time ensure that the water inlet box 6 and the water outlet box 7 completely cover the crack.

[0049] (2) Place the water inlet box 6, the concrete specimen 5, and the water outlet box 7 between the first limiting plate 401 and the second limiting plate 402 of the limiting mechanism 4. By rotating the locking nut 404, adjust the relative movement of the first limiting plate 401 and the second limiting plate 402 and press them tightly against the surfaces of the water inlet box 6 and the water outlet box 7.

[0050] (3) Connect the constant pressure air pump 1 to the first air inlet pipe 22 of the pressurized water tank 2, open the first air valve 8, close the first water valve 15 and the first return valve 12, start the constant pressure air pump 1, calculate the seepage pressure according to the underwater service depth of the concrete, and set the output air pressure of the constant pressure air pump 1 to the calculated seepage pressure.

[0051] (4) Close the second reflux valve 13 of the water storage tank 3, open the second water valve 18 and the second air valve 20; then open the first water valve 15, and the water in the pressurized water tank 2 enters the water storage tank 3 through the water inlet pipe 14, the water inlet box 6, the cracked concrete specimen 5, the water outlet box 7 and the water outlet pipe 17, and record the water head difference Δh1 between the pressurized water tank 2 and the water storage tank 3 within a specified time.

[0052] (5) After the recording is completed, connect the constant pressure air pump 1 to the second air inlet pipe 19 of the water storage tank 3, close the second water valve 18 and the first water valve 15, open the first air valve 8, the first reflux valve 12 and the second reflux valve 13, then open the second air valve 20, start the constant pressure air pump 1, and make the water in the water storage tank 3 enter the pressurized water tank 2 through the reflux pipe 11 until the original water head heights of the pressurized water tank 2 and the water storage tank 3 are restored, and prepare for the next test.

[0053] (6) Repair the cracked concrete specimen. After the repair is completed, use the methods of (1) - (5) to test the cracked area and the uncracked area of the concrete specimen after repair, and record the water head differences between the pressurized water tank and the water storage tank within a specified time as Δh2 and Δh3 respectively.

[0054] (7) Quantitatively evaluate the repair effect of the cracked concrete specimen based on the measured data, and the calculation formula is:

[0055]

[0056] In the formula, x t is the repair index calculated for the fixed time t, and Δh1, Δh2 and Δh3 are the water head differences between the pressurized water tank and the water storage tank measured in the cracked area, the cracked area after repair and the uncracked area of the concrete specimen within the specified time t respectively.

[0057] (8) Evaluate the calculated repair index x t according to Table 1 below.

[0058] Table 1 Repair effect evaluation table

[0059] Repair index 0～0.6 0.6～0.75 0.75～0.9 0.9～1.0 Repair evaluation Unqualified Qualified Good Excellent

[0060] Example 3

[0061] This example provides a method for quantitatively evaluating the permeability performance of cracked concrete after repair by using the device described in Example 1, including the following steps:

[0062] (1) Place the water inlet box 6 and the water outlet box 7 on both sides of the cracked concrete specimen 5, keep the cracked surface of the concrete specimen 5 perpendicular to the ground to reduce the influence of gravity on the test, and at the same time ensure that the water inlet box 6 and the water outlet box 7 completely cover the crack.

[0063] (2) Place the water inlet box 6, the concrete specimen 5, and the water outlet box 7 between the first limiting plate 401 and the second limiting plate 402 of the limiting mechanism 4. By rotating the locking nut 404, adjust the relative movement of the first limiting plate 401 and the second limiting plate 402 and press them tightly against the surfaces of the water inlet box 6 and the water outlet box 7.

[0064] (3) Connect the constant pressure air pump 1 to the first air inlet pipe 22 of the pressurized water tank 2. Open the first air valve 8, close the first water valve 15 and the first reflux valve 12, start the constant pressure air pump 1, calculate the seepage pressure according to the underwater service depth of the concrete, and set the output air pressure of the constant pressure air pump 1 to the calculated seepage pressure.

[0065] (4) Close the second reflux valve 13 of the water storage tank 3, open the second water valve 18 and the second air valve 20; then open the first water valve 15. The water in the pressurized water tank 2 enters the water storage tank 3 after passing through the water inlet pipe 14, the water inlet box 6, the cracked concrete specimen 5, the water outlet box 7, and the water outlet pipe 17. Record the time t1 required for the pressurized water tank 2 and the water storage tank 3 to reach the specified water head difference.

[0066] (5) After the recording is completed, connect the constant pressure air pump 1 to the second air inlet pipe 19 of the water storage tank 3, close the second water valve 18 and the first water valve 15, open the first air valve 8, the first reflux valve 12 and the second reflux valve 13, then open the second air valve 20, and start the constant pressure air pump 1 to make the water in the water storage tank 3 enter the pressurized water tank 2 through the reflux pipe 11 until the pressurized water tank 2 and the water storage tank 3 return to the original water head height to prepare for the next test.

[0067] (6) Repair the cracked concrete specimen. After the repair is completed, use the methods of (1) to (5) to test the cracked area and the uncracked area after the repair of the concrete specimen, and record the times required for the pressurized water tank and the water storage tank to reach the specified water head difference as t2 and t3 respectively.

[0068] (7) Based on the measured data, quantitatively evaluate the repair effect of the cracked concrete specimen. The calculation formula is:

[0069]

[0070] Where x h is the repair index calculated from the fixed water head difference h. Δt1, Δt2, and Δt3 are the times required for the cracked area, the cracked area after repair, and the uncracked area of the concrete specimen to reach the specified water head difference h between the pressurized water tank and the water storage tank respectively.

[0071] (8) Evaluate the calculated repair index x h according to Table 1 in Example 2.

[0072] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for quantitatively evaluating the permeability performance of cracked concrete after repair, characterized in that, It includes the following steps: Calculate the seepage pressure according to the underwater service depth of the concrete specimen, and set the air pressure of the constant-pressure air pump to the seepage pressure; Open the pressurized water tank, so that the water in the pressurized water tank enters the water storage tank after passing through the water inlet box, the cracked concrete specimen and the water outlet box. Take the water head difference between the pressurized water tank and the water storage tank within a specified time or the time required for the pressurized water tank and the water storage tank to reach a specified water head difference as the performance evaluation parameter, and record the numerical value of the performance evaluation parameter; Repair the cracked concrete specimen. After the repair is completed, use the aforementioned method to test the cracked area and the uncracked area of the concrete specimen after repair, and record the numerical value of the performance evaluation parameter; Quantitatively evaluate the repair effect of the cracked concrete specimen based on the measured numerical values of the performance evaluation parameters; The device for quantitatively evaluating the permeability performance of cracked concrete after repair adopted by the method includes a constant-pressure air pump, a pressurized water tank, a water inlet box, a water outlet box, a limiting mechanism and a water storage tank; The water inlet box and the water outlet box are relatively arranged on both sides of the concrete specimen to be tested, and the limiting mechanism is used to fix and limit the water inlet box, the concrete specimen and the water outlet box; The constant-pressure air pump is connected to the pressurized water tank, the pressurized water tank is connected to the water inlet box, the water storage tank is connected to the water outlet box, and the water storage tank is connected to the pressurized water tank through a return pipe.

2. The method for quantitatively evaluating the permeability performance of cracked concrete after repair according to claim 1, wherein Both the water inlet box and the water outlet box are box bodies with an opening on one side, and a sealing rubber ring is provided at the edge of the opening side.

3. The method for quantitatively evaluating the permeability performance of cracked concrete after repair according to claim 1, characterized in that, The limiting mechanism includes a first limiting plate, a second limiting plate, a guide rail and a threaded rod. The first limiting plate and the second limiting plate are arranged oppositely. The guide rail slidably penetrates through the first limiting plate and the second limiting plate. The threaded rod penetrates through the first limiting plate and the second limiting plate, and a locking nut for adjusting the positions of the first limiting plate and the second limiting plate is sleeved outside the threaded rod.

4. The method for quantitatively evaluating the permeability performance of cracked concrete after repair according to claim 1, characterized in that A pressure gauge and a first air inlet pipe are provided on the top of the pressurized water tank. A first air valve is provided on the first air inlet pipe, and a first transparent scale is provided on the pressurized water tank.

5. The method for quantitatively evaluating the permeability performance of cracked concrete after repair according to claim 1, characterized in that, A second air inlet pipe is provided on the top of the water storage tank. A second air valve is provided on the second air inlet pipe, and a second transparent scale is provided on the water storage tank.

6. The method for quantitatively evaluating the permeability performance of cracked concrete after repair according to claim 1, characterized in that, The bottom of the pressurized water tank is connected to the water inlet box through a water inlet pipe. A flow velocity sensor is provided on the water inlet pipe. A first water valve is provided at the connection between the pressurized water tank and the water inlet pipe, and a first return valve is provided at the connection between the pressurized water tank and the return pipe.

7. The method for quantitatively evaluating the permeability performance of cracked concrete after repair according to claim 1, characterized in that, The bottom of the water storage tank is connected to the water outlet box through a water outlet pipe. A second water valve is provided at the connection between the water storage tank and the water outlet pipe, and a second return valve is provided at the connection between the water storage tank and the return pipe.

8. The method for quantitatively evaluating the permeability performance of cracked concrete after repair according to claim 1, characterized in that It includes the following steps: Place the water inlet box and the water outlet box on both sides of the cracked concrete specimen, ensure that the water inlet box and the water outlet box completely cover the crack, and then fix the water inlet box, the concrete specimen and the water outlet box through the limiting mechanism; Close the return pipe, connect the constant-pressure air pump to the pressurized water tank, calculate the seepage pressure according to the underwater service depth of the concrete specimen, and set the air pressure of the constant-pressure air pump to the seepage pressure; Open the pressurized water tank so that the water in the pressurized water tank enters the water storage tank after passing through the water inlet box, the cracked concrete specimen, and the water outlet box. Take the water head difference between the pressurized water tank and the water storage tank within a specified time or the time required for the pressurized water tank and the water storage tank to reach a specified water head difference as the performance evaluation parameter, and record the value of the performance evaluation parameter; After the recording is completed, open the return pipe, connect the constant pressure air pump to the water storage tank, and make the water in the water storage tank enter the pressurized water tank through the return pipe until the water head heights of the pressurized water tank and the water storage tank are restored to the original levels; Repair the cracked concrete specimen. After the repair is completed, use the aforementioned method to test the cracked area and the uncracked area of the concrete specimen after repair, and record the value of the performance evaluation parameter; Quantitatively evaluate the repair effect of the cracked concrete specimen based on the measured values of the performance evaluation parameter.

9. The method for quantitatively evaluating the permeability performance of cracked concrete after repair according to claim 8, characterized in that, The performance evaluation parameter is the water head difference between the pressurized water tank and the water storage tank within a specified time. The calculation formula for quantitative evaluation based on this performance evaluation parameter is: ； In the formula, x t is the fixed time t is the calculated repair index, , and are the head differences between the pressurized water tank and the water storage tank measured inside the cracked area, the cracked area after repair, and the uncracked area of the concrete specimen at the specified time t respectively.

10. The method for quantitatively evaluating the permeability performance of repaired cracked concrete according to claim 8, wherein, The performance evaluation parameter is the time required for the pressurized water tank and the water storage tank to reach a specified water head difference. The calculation formula for quantitative evaluation based on this performance evaluation parameter is: ； Wherein, x h is the fixed head difference h is the calculated repair index , and are the times required for the cracked area, the repaired cracked area and the uncracked area of the concrete specimen to reach the specified head difference h in the pressure water tank and the water storage tank, respectively.

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