Method for testing impermeability of impermeable material

Abstract

The invention discloses a method for testing the impermeability of an impermeable material. The method comprises the following steps: preparing a sample of the impermeable material to be detected; fixing the sample in an anti-permeability testing device, and connecting the sample with a crack expansion device; the impermeability testing device is used for providing seepage water pressure for the sample; the crack expansion device is used for providing tensile force for the sample; under the seepage water pressure environment provided by the impermeability testing device, the crack expansion device provides tensile force for the sample, so that the center of the sample is separated towards the two sides to form cracks; the seepage water pressure of the sample in the anti-permeability testing device is detected in real time in the process that the center of the sample is separated towards the two sides to form cracks; and judging whether the anti-seepage material is qualified or not according to the seepage water pressure and the shape of the anti-seepage material on the tested sample. The crack expansion device and the impermeability testing device are used for simulating the effect that the base material generates cracks for the sample, the change of the impermeable material when the base material generates the cracks is dynamically simulated, and the impermeability performance of the impermeable material is evaluated more accurately.

Description

Technical Field

[0001] The invention belongs to the field of anti-seepage material testing, and particularly relates to a method for testing the anti-seepage performance of an anti-seepage material. Background Art

[0002] In water conservancy and hydropower projects, such as reservoirs, cisterns, and riverbanks, impermeable materials are applied to the surface of the foundation material to prevent seepage. These materials consist of a rigid base material and a flexible impermeable material, with the base material providing structural support and the impermeable material responsible for preventing seepage. In actual projects, cracks may form in the base material due to uneven settlement, stress concentration, temperature fluctuations, and frost heave in hydraulic structures. Furthermore, the impermeable material tends to harden at low temperatures, and expansion of these cracks can tear the material, causing leakage and endangering the safety of the hydraulic structure. Therefore, it is necessary to test the impermeability of the impermeable material when cracks in the base material expand at low temperatures.

[0003] In the related art, the anti-seepage performance of anti-seepage materials is tested through the anti-seepage performance of static materials or materials with static cracks. It is difficult to dynamically simulate the changes of the anti-seepage material when cracks appear in the substrate, and the evaluation of the anti-seepage performance of the anti-seepage material is not accurate enough. Summary of the Invention

[0004] The purpose of the present invention is to propose a method for testing the anti-seepage performance of anti-seepage materials, so as to solve the problem in the prior art that it is difficult to dynamically simulate the changes of anti-seepage materials when cracks occur in the substrate, and the anti-seepage performance evaluation of anti-seepage materials is not accurate enough.

[0005] To this end, a first aspect of the present invention provides a method for testing the anti-seepage performance of an anti-seepage material, comprising the following steps:

[0006] Prepare samples of anti-seepage materials to be tested;

[0007] Fixing the sample in an anti-permeability testing device and connecting it to a crack expansion device; the anti-permeability testing device is used to provide permeation water pressure to the sample; the crack expansion device is used to provide tension to the sample;

[0008] Under the permeation water pressure environment provided by the anti-permeability testing device, the crack expansion device provides tension to the sample, causing the center of the sample to separate to both sides to form cracks;

[0009] Real-time detection of the permeation water pressure of the sample in the anti-permeability testing device during the process of the sample center separating to both sides to form cracks;

[0010] The qualification of the anti-seepage material is determined based on the penetration water pressure and the shape of the anti-seepage material on the sample after the test.

[0011] Preferably, the step of preparing a sample of the anti-seepage material to be tested comprises:

[0012] Combining two semi-cylindrical test substrates, wherein the test substrates are pre-installed with tie rod anchor sheets;

[0013] Applying or bonding an anti-seepage material on the surface of the test substrate;

[0014] The anti-seepage material is solidified into a shape.

[0015] Preferably, the crack expansion device includes a drive motor and a pull rod, and the drive motor is fixedly connected to the pull rod.

[0016] Preferably, the anti-seepage testing device includes: a surrounding water pressure chamber, a seepage water pressure chamber is provided at the bottom of the surrounding water pressure chamber, a seepage outlet is provided at the top of the surrounding water pressure chamber, water enters the surrounding water pressure chamber from the seepage water pressure chamber and is discharged from the seepage outlet, and the pull rod passes through the side wall of the surrounding water pressure chamber to the interior of the surrounding water pressure chamber.

[0017] Preferably, fixing the sample in the anti-permeability testing device and connecting it to the crack expansion device includes:

[0018] Apply lubricant evenly on the surface of the sample;

[0019] Attach copper sheets to both ends of the gap between the two test substrates;

[0020] The top and bottom of the specimen are compacted by permeable stones;

[0021] Covering the sample with a latex film;

[0022] The sample is fixed in the ambient water pressure chamber, and the tie rod is fixedly connected to the tie rod anchoring plate.

[0023] Preferably, when the pull rod is fixedly connected to the pull rod anchoring plate, it penetrates the latex film covering the outside of the sample, and the latex film is bonded to the surface of the sample by an adhesive at the position where the pull rod penetrates the latex film.

[0024] Preferably, the pull rod and the surrounding water pressure chamber are sealed by a pressure-resistant water stop ring.

[0025] Preferably, the temperature of the ambient water in the ambient water pressure chamber is adjusted by ice particles or hot water, and the temperature of the permeated water in the permeated water pressure chamber is adjusted by ice particles or hot water.

[0026] Preferably, the pressure difference between the ambient water pressure of the ambient water pressure chamber and the osmotic water pressure of the osmotic water pressure chamber is at least greater than 30 kPa, and the ambient water pressure of the ambient water pressure chamber is greater than the osmotic water pressure of the osmotic water pressure chamber.

[0027] Preferably, judging whether the anti-seepage material is qualified according to the permeation water pressure and the shape of the anti-seepage material on the sample after the test includes:

[0028] If the anti-seepage material is torn or peeled off from the top surface of the sample, the seepage water seeps into the cracks of the sample, and the seepage water pressure decreases, it is judged that the anti-seepage material is damaged and the anti-seepage performance of the anti-seepage material is unqualified; if the anti-seepage material is not damaged, the seepage water does not seep into the cracks of the sample, and the seepage water pressure remains unchanged, it is judged that the anti-seepage material is not damaged and the anti-seepage performance of the anti-seepage material is qualified.

[0029] Beneficial effects:

[0030] 1. The present invention provides a method for testing the anti-seepage performance of anti-seepage materials. The method uses a crack expansion device and an anti-seepage testing device to simulate the effect of cracks in the substrate for the sample, dynamically simulates the changes in the anti-seepage material when cracks are generated in the substrate, and more accurately evaluates the anti-seepage performance of the anti-seepage material.

[0031] 2. In the present invention, copper sheets are attached to both ends of the gap between the two test substrates to provide support for the cracks generated in the test substrates, thereby preventing the latex film from collapsing into the cracks and affecting the test results.

[0032] 3. In the present invention, the temperature of the surrounding water in the surrounding water pressure chamber is adjusted by ice particles or hot water, and the temperature of the infiltrated water in the infiltrated water pressure chamber is adjusted by ice particles or hot water, thereby simulating the temperature in winter or summer and improving the applicability of the anti-seepage performance testing of the anti-seepage material. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 The present invention provides a flow chart of a method for testing the anti-seepage performance of an anti-seepage material.

[0035] Figure 2 The figure is a schematic structural diagram of a method for testing the anti-seepage performance of an anti-seepage material in the present invention.

[0036] Figure 3 This is a schematic structural diagram of a sample used in a method for testing the anti-seepage performance of an anti-seepage material in the present invention.

[0037] In the figure, 1-pressure chamber top cover; 2-permeable stone; 3-surrounding water pressure chamber; 4-latex membrane; 5-test substrate; 6-crack; 7-anti-seepage material; 8-seepage water pressure chamber; 9-instrument base; 10-seepage outlet; 11-rubber band; 12-ice particles; 13-pull rod anchor plate; 14-pressure-resistant water stop ring; 15-pull rod; 16-copper sheet; 17-surrounding water pressure chamber water inlet; 18-seepage water pressure chamber water inlet; 19-drive motor. DETAILED DESCRIPTION

[0038] The present invention may be more readily understood by referring to the following detailed description of preferred embodiments of the present invention and the included Examples. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention pertains. In the event of a conflict, the definitions in this specification shall prevail.

[0039] Example 1:

[0040] like Figure 1 As shown, the first aspect of this embodiment provides a method for testing the anti-seepage performance of an anti-seepage material, comprising the following steps:

[0041] S1, preparing a sample of the anti-seepage material 7 to be tested;

[0042] These include:

[0043] S11. Combine two semi-cylindrical test substrates 5, each pre-installed with a tie rod 15 and anchoring plate 13. The two semi-cylindrical test substrates 5 are aligned with each other to form a complete cylinder. The location of the flat surfaces forming the crack 6 formed by subsequent stretching simulates the cracking conditions of a hydraulic structure foundation. The height and diameter of the semi-cylindrical test substrate 5 are greater than 30 mm, and preferably 40 mm. The tie rod 15 and anchoring plate 13 are pre-installed in the test substrate 5. A nut is welded to the tie rod 15 and fixedly connected to the nut through a hole in the test substrate 5. The tie rod 15 is driven by a motor to move the specimen. The tie rod 15, anchoring plate 13, nut, and tie rod 15 can be made of metal or non-metallic materials with a certain hardness and strength, such as steel or iron. The test substrate 5 can be made of concrete or asphalt concrete, and the anti-seepage material can be petroleum asphalt polyurethane. In one embodiment, the anti-seepage material is a high-toughness polymer flexible auxiliary anti-seepage protection material developed by China Water Resources Northeast Survey, Design and Research Co., Ltd.

[0044] S12, applying or bonding an anti-seepage material 7 on the surface of the test substrate 5;

[0045] S13, solidifying the anti-seepage material 7. By testing the anti-seepage body composed of the substrate 5 and the anti-seepage material 7, a hydraulic structure is simulated to improve the accuracy of the anti-seepage performance test.

[0046] S2. Fixing the sample in an anti-permeability testing device and connecting it to a crack expansion device; the anti-permeability testing device is used to provide permeation water pressure to the sample; the crack expansion device is used to provide tension to the sample;

[0047] in,

[0048] The crack expansion device includes a drive motor 19 and a pull rod 15, which are fixedly connected to each other. Two crack expansion devices are provided, one on each side of the impermeability tester. The drive motor 19 and the pull rod 15 are positioned at the same height as the hole in the specimen, providing sufficient tension to pull the specimen, causing a crack, and dynamically adjusting the size of the crack 6.

[0049] The anti-seepage testing device includes: a surrounding water pressure chamber 3, a seepage water pressure chamber 8 is provided at the bottom of the surrounding water pressure chamber 3, and a seepage outlet 10 is provided at the top of the surrounding water pressure chamber 3. Water enters the surrounding water pressure chamber 3 from the seepage water pressure chamber 8 and is discharged from the seepage outlet 10. The pull rod 15 passes through the side wall of the surrounding water pressure chamber 3 to the interior of the surrounding water pressure chamber 3.

[0050] Furthermore, in one embodiment, a pressure chamber cover 1 is provided on the top of the surrounding water pressure chamber 3, and a seepage outlet 10 is provided on the pressure chamber cover 1. A surrounding water pressure chamber inlet 17 is provided on the side wall of the surrounding water pressure chamber. A seepage water pressure chamber inlet 18 is provided on the side wall of the seepage water pressure chamber 8.

[0051] The surrounding water pressure chamber 3 is made of transparent materials, such as glass, acrylic plate, and organic glass, which meets the pressure strength requirements during the test and can penetrate the deformation of the anti-seepage material 7 in time.

[0052] The anti-permeability testing device and the crack expansion device are fixedly mounted on the instrument base 9 .

[0053] When the pull rod 15 is fixedly connected to the pull rod 15 anchor plate 13, it penetrates the latex film 4 covering the outside of the sample, and the latex film 4 is bonded to the surface of the sample by an adhesive at the position where the pull rod 15 penetrates the latex film 4. The latex film 4 at the position where the pull rod 15 penetrates is sealed to the surface of the sample by the adhesive, thereby improving the sealing performance. In one embodiment, the diameter of the pull rod 15 is 10 mm, and a hole with the same diameter as the pull rod 15 is provided on the latex film 4 at the position where the pull rod 15 penetrates the latex film 4. The adhesive is M&G Stationery Super Glue 502 Adhesive.

[0054] The pull rod 15 and the surrounding water pressure chamber 3 are sealed by a pressure-resistant water-stop ring 14 to improve the sealing performance and ensure the detection effect.

[0055] These include:

[0056] S21. Apply lubricant evenly on the surface of the sample; wherein the lubricant is preferably vaseline.

[0057] S22. Attach copper sheets 16 to both ends of the gaps in the two test substrates 5. The copper sheets 16 have a height consistent with the specimen and a width at least twice that of the crack 6. In one embodiment, the copper sheets 16 have a height of 40 mm, a width of 60 mm, and a thickness of 1 mm.

[0058] S23. The top and bottom of the sample are compressed with permeable stones 2. The permeable stones 2 are circular and have a diameter larger than that of the sample, meeting the positional requirements for the expansion of the crack 6 in the sample. The diameters of the pressure chamber top cover 1 and the instrument base 9 where the sample is fixed are consistent with the diameter of the circular permeable stones 2. In one embodiment, the diameter of the permeable stones 2 is 60 mm.

[0059] S24. Cover the sample with a latex film 4. In one embodiment, the latex film 4 is a φ39.1*80 mm transparent latex film 4 produced by Suzhou Shali Industrial Products Co., Ltd.

[0060] S25, fix the sample in the surrounding water pressure chamber 3, and fix the tie rod 15 to the tie rod 15 anchor plate 13. The latex membrane 4 is put on the sample base and the pressure chamber top cover 1, and is tightly sealed with a rubber band 11 to improve the sealing performance.

[0061] The latex film 4 is used to prevent water from leaking along the outer wall of the sample and to seal the sample. The copper sheet 16 is used to withstand the water pressure after the test substrate 5 is separated to form the crack 6, so as to prevent the latex film 4 from being pressed into the crack 6 by the water pressure and affecting the test results.

[0062] S3. Under the permeation water pressure environment provided by the anti-permeability testing device, the crack expansion device applies a tensile force to the sample, causing the center of the sample to separate toward both sides to form a crack 6;

[0063] in:

[0064] Ice particles 12 or hot water are used in the ambient water pressure chamber 3 to regulate the temperature of the surrounding water therein. Ice particles 12 or hot water are also used in the permeated water pressure chamber 8 to regulate the temperature of the permeated water therein. Adjusting the water temperature with ice particles 12 or hot water simulates winter or summer temperatures, improving the applicability of testing the impermeability performance of the impermeable material 7. In one embodiment, ice particles 12 are used to lower the temperature of the sample and the permeated water. Ambient water pressure is applied first, followed by permeated water pressure.

[0065] The pressure difference between the ambient water pressure of the ambient water pressure chamber 3 and the osmotic water pressure of the osmotic water pressure chamber 8 is at least greater than 30kPa, and the ambient water pressure of the ambient water pressure chamber 3 is greater than the osmotic water pressure of the osmotic water pressure chamber 8. To prevent the osmotic water from leaking between the sample and the latex membrane 4, the osmotic water pressure can be adjusted according to the actual working conditions of the project. The ambient pressure application levels are 50kPa, 100kPa, 200kPa, 300kPa, 400kPa, and 500kPa, respectively, and the osmotic water pressure application levels are 20kPa, 60kPa, 150kPa, 250kPa, 350kPa, and 450kPa, respectively. The ambient water pressure presses the latex membrane 4 tightly against the surface of the sample, preventing the osmotic water from leaking between the sample and the latex membrane 4.

[0066] After the seepage water pressure is raised to the design water pressure, the motor is started to drive the pull rod 15 to drag the semicircular main body test substrate 5 sample, so that the cracks 6 between the samples gradually expand. The anti-seepage material 7 is stretched and becomes thinner as the cracks 6 expand. The anti-seepage performance of the anti-seepage material 7 during the expansion of the substrate cracks 6 under low temperature conditions is tested.

[0067] S4, real-time detection of the permeation water pressure of the sample in the anti-permeability testing device during the process of the sample center separating to both sides to form a crack 6;

[0068] S5. Determine whether the anti-seepage material 7 is qualified based on the permeation water pressure and the shape of the anti-seepage material 7 on the sample after the test.

[0069] If the anti-seepage material 7 is torn or peeled off from the top surface of the sample, the seepage water leaks into the crack 6 of the sample, and the seepage water pressure decreases, it is judged that the anti-seepage material 7 is damaged and the anti-seepage performance of the anti-seepage material 7 is unqualified; if the anti-seepage material 7 is not damaged, the seepage water does not penetrate into the crack 6 of the sample, and the seepage water pressure remains unchanged, it is judged that the anti-seepage material 7 is not damaged and the anti-seepage performance of the anti-seepage material 7 is qualified.

[0070] In one embodiment, the thickness change of the anti-seepage material 7 after the crack 6 of the test substrate 5 expands is shown in the following table:

[0071]

[0072] Comparative Example 1:

[0073] Comparative Example 1 differs from Example 1 in that the specimen lacks copper sheets 16 at either end of the crack 6 in the test substrate 5. When the surrounding water pressure reaches 50 kPa, the latex membrane 4 significantly collapses into the crack 6. When the surrounding water pressure reaches 100 kPa, the latex membrane 4 on either side of the crack 6 adheres to the inner wall of the crack 6, affecting the seal and, consequently, the results of the water-resistance test. The copper sheets 16 in Example 1 provide support for the latex membrane 4, effectively preventing the collapse of the latex membrane 4.

[0074] Comparative Example 2:

[0075] Comparative Example 2 differs from Example 1 in that the latex membrane 4 is not bonded to the specimen with adhesive at the location where the tie rod 15 penetrates the membrane. When ambient water pressure is applied, water enters between the latex membrane 4 and the specimen surface, causing leakage and affecting the results of the anti-permeation test. In Example 1, the latex membrane 4 is bonded to the specimen surface with adhesive, providing a sealed seal and eliminating the leakage problem at the openings in the latex membrane 4.

[0076] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for testing the anti-seepage performance of an anti-seepage material, characterized in that: include: Prepare samples of anti-seepage materials to be tested; Fixing the sample in an anti-permeability testing device and connecting it to a crack expansion device; the anti-permeability testing device is used to provide permeation water pressure to the sample; the crack expansion device is used to provide tension to the sample; Under the permeation water pressure environment provided by the anti-permeability testing device, the crack expansion device provides tension to the sample, causing the center of the sample to separate to both sides to form a crack; Real-time detection of the permeation water pressure of the sample in the anti-permeability testing device during the process of the sample center separating to both sides to form cracks; The qualification of the anti-seepage material is determined based on the penetration water pressure and the shape of the anti-seepage material on the sample after the test.

2. The method for testing the anti-seepage performance of an anti-seepage material according to claim 1, wherein: The preparation of the sample of the anti-seepage material to be tested comprises: Combining two semi-cylindrical test substrates, wherein the test substrates are pre-installed with tie rod anchor sheets; Applying or bonding an anti-seepage material on the surface of the test substrate; The anti-seepage material is solidified into a shape.

3. The method for testing the anti-seepage performance of an anti-seepage material according to claim 2, wherein: The crack expansion device includes a driving motor and a pull rod, and the driving motor is fixedly connected to the pull rod.

4. The method for testing the anti-seepage performance of an anti-seepage material according to claim 3, wherein: The anti-seepage testing device includes: a surrounding water pressure chamber, a seepage water pressure chamber is provided at the bottom of the surrounding water pressure chamber, a seepage outlet is provided at the top of the surrounding water pressure chamber, water enters the surrounding water pressure chamber from the seepage water pressure chamber and is discharged from the seepage outlet, and the pull rod passes through the side wall of the surrounding water pressure chamber to the interior of the surrounding water pressure chamber.

5. The method for testing the anti-seepage performance of an anti-seepage material according to claim 4, wherein: The step of fixing the sample in the anti-permeability testing device and connecting the sample to the crack expansion device comprises: Apply lubricant evenly on the surface of the sample; Attach copper sheets to both ends of the gap between the two test substrates; The top and bottom of the specimen are compacted by permeable stones; Covering the sample with a latex film; The sample is fixed in the ambient water pressure chamber, and the tie rod is fixedly connected to the tie rod anchoring plate.

6. The method for testing the anti-seepage performance of an anti-seepage material according to claim 5, characterized in that: When the pull rod is fixedly connected to the pull rod anchoring sheet, it penetrates the latex film covering the outside of the sample. The position where the pull rod penetrates the latex film is used to bond the latex film to the surface of the sample through an adhesive.

7. The method for testing the anti-seepage performance of an anti-seepage material according to claim 4, wherein: The pull rod and the surrounding water pressure chamber are sealed by a pressure-resistant water stop ring.

8. The method for testing the anti-seepage performance of an anti-seepage material according to claim 4, wherein: The temperature of the ambient water in the ambient water pressure chamber is adjusted by ice particles or hot water, and the temperature of the permeated water in the permeated water pressure chamber is adjusted by ice particles or hot water.

9. The method for testing the anti-seepage performance of an anti-seepage material according to claim 4, wherein: The pressure difference between the ambient water pressure of the ambient water pressure chamber and the permeated water pressure of the permeated water pressure chamber is at least greater than 30 kPa, and the ambient water pressure of the ambient water pressure chamber is greater than the permeated water pressure of the permeated water pressure chamber.

10. The method for testing the anti-seepage performance of an anti-seepage material according to claim 1, wherein: The method of judging whether the anti-seepage material is qualified according to the permeation water pressure and the shape of the anti-seepage material on the test sample includes: If the anti-seepage material is torn or peeled off from the top surface of the sample, the seepage water seeps into the cracks of the sample, and the seepage water pressure decreases, it is judged that the anti-seepage material is damaged and the anti-seepage performance of the anti-seepage material is unqualified; if the anti-seepage material is not damaged, the seepage water does not seep into the cracks of the sample, and the seepage water pressure remains unchanged, it is judged that the anti-seepage material is not damaged and the anti-seepage performance of the anti-seepage material is qualified.

Images