Self-induction deformation geobelt and preparation method thereof

Abstract

The preparation method comprises the following steps: cutting a single-rib geogrid strip on a geogrid, and brushing an electric coating mixture on the single-rib geogrid strip by using a roller coating mold, a spacing distance is selected on the surface of the conductive film, a conductive adhesive tape is used for manufacturing an electrode, a wire is led out to form a loop to serve as a measuring section, a roller coating mold is used for evenly covering the conductive film with liquid silicone rubber, sealing treatment is conducted, and then the self-induction deformation geobelt is obtained. The prepared self-induction deformation geobelt has good linearity and sensitivity and a large measuring range, can meet the requirement for monitoring large deformation of a soil body and is small in null drift, the resistance characteristic of the sensing geobelt can be affected by temperature rising and falling of the external environment, and the double effects of heat preservation and water resistance can be achieved by coating silicone rubber.

Description

Technical Field

[0001] The invention relates to the technical field of geobelt preparation, in particular to a self-inductively deformed geobelt and a preparation method thereof. Background Art

[0002] As an important material in civil engineering, geotextiles are low-cost, thermally stable, anti-corrosive, high tensile strength, and no long-term creep. They are widely used in slope stabilization, foundation reinforcement, soil erosion control, and other fields.

[0003] However, the uniformity of the conductive coating is directly related to the conductive performance of the geotextile fiberglass strips. If the coating is not applied evenly, it may cause discontinuity or interruption of the conductive path, thereby increasing the surface resistivity and reducing the conductive performance. This will affect the performance of the geotextile in applications that require conductive properties, such as electromagnetic shielding, electrostatic protection, etc.

[0004] The uniformity of the conductive coating also affects the physical and chemical properties of the geotextile fiberglass strips. Uneven coating may lead to structural instability or residual solvents in the paint film, thereby reducing its durability, weather resistance and corrosion resistance. The degradation of these properties will affect the service life and stability of the geotextile.

[0005] The uniformity of conductive coating is one of the key factors affecting the overall quality and reliability of geotextiles. Uneven coating may cause local failure or performance degradation of geotextiles during use, thus affecting the quality and reliability of the entire project. This problem is particularly prominent in application scenarios that require high reliability and stability, such as highways and water conservancy projects.

[0006] Therefore, it becomes crucial to ensure the uniformity of the conductive coating on the geotextile belt. Summary of the invention

[0007] The purpose of the present invention is to provide a self-deformed geotextile belt and a preparation method thereof, by optimizing the coating formula: selecting high-quality conductive coating and ensuring its reasonable ratio to meet the requirements of conductive performance and coating uniformity, while improving the coating process to ensure the uniformity of the conductive coating.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] A method for preparing a self-deformed geotextile belt, the preparation steps of which include:

[0010] Cutting, cutting out single-rib geogrid strips from the geogrid, retaining some grid transverse ribs on the single-rib geogrid strips, and keeping the width and cut of the single-rib geogrid strips uniform;

[0011] Conductive coating is applied by using a roller coating mold to apply an electric coating mixture to the single-rib geogrid strip, and a conductive film is obtained after the applied electric coating mixture is cured and formed;

[0012] Sealing, selecting a spacing distance on the surface of the conductive film, using conductive tape to make electrodes and lead out wires to form a loop as a measuring section, and using a roller coating mold to evenly cover the conductive film with liquid silicone rubber for sealing, to obtain a self-inductively deformed geotextile. The purpose of sealing the geotextile is to provide waterproof and heat insulation.

[0013] According to the above technical solution, the electro-coating mixture is a mixture of conductive coating slurry and a curing agent.

[0014] According to the above technical solution, the mass ratio of the conductive coating slurry to the curing agent is 10:1.

[0015] According to the above technical solution, the roller coating mold includes a rubber frame, a brush roller, and a brush push rod; the brush roller is arranged above the rubber frame, and the brush push rod is arranged on the side of the brush roller.

[0016] According to the above technical solution, during the conductive paint coating process, rubber frames of different sizes can be used to evenly control the length, width and height of the conductive paint mixture filling.

[0017] According to the above technical solution, the specific steps of applying the conductive coating include:

[0018] Place the rubber frame evenly on the grid to be coated on the single-rib geogrid strip;

[0019] Apply electrocoat mixture inside the rubber frame;

[0020] During the painting process, the painting push rod is used to push the painting roller to roll back and forth on the rubber frame 3-4 times;

[0021] After the electro-brush coating mixture is initially cured for 5-10 minutes, the rubber frame is taken out, and a conductive film is obtained on the grid to be coated on the single-rib geogrid strip.

[0022] Among them, the conductive coating gradually solidifies under the action of the curing agent, and the initial resistance value of the conductive film after curing begins to decrease from a higher value of about 1700Ω and gradually stabilizes to about 1450Ω. At this time, a complete conductive network structure has been formed inside the conductive film.

[0023] According to the above technical solution, the conductive film is evenly sprayed with water during the drying process after the liquid silicone rubber is applied to promote the curing and molding of the liquid silicone rubber.

[0024] Also included is another embodiment, a self-deformable geotextile belt, which is made by the above-mentioned method for preparing a self-deformable geotextile belt.

[0025] Compared with the prior art, the beneficial effects achieved by the present invention are: the self-sensing deformable geotextile belt produced by the present invention has good linearity, sensitivity and a large measuring range, can meet the needs of large soil deformation monitoring, and has a small zero drift. The temperature rise and fall of the external environment will affect the resistance characteristics of the sensor geotextile belt. The coating of silicone rubber can have a dual effect of heat preservation and waterproofing. Compared with the sensitivity of the sensor geotextile belt, the temperature has little effect, which shows that the flexible conductive film is not sensitive to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 It is a flow chart of the steps of a method for preparing a self-inductively deformable geotextile belt according to the present invention;

[0028] Figure 2 is a top view of a roller coating die of an embodiment;

[0029] Figure 3 is a resistance change curve diagram of the conductive film curing process of the embodiment;

[0030] Figure 4 It is a schematic diagram of a geotextile belt with self-induced deformation;

[0031] Figure 5 is a graph showing the average stress-strain relationship of the geotextile belt of the embodiment;

[0032] Figure 6 is the average resistance change rate-strain curve of the geotextile belt of the embodiment;

[0033] Figure 7 is a time curve diagram of FBG and conductive film measurement in the embodiment;

[0034] Figure 8 is a graph of a zero drift test of a geotextile belt in an embodiment;

[0035] Fig. 9 is a graph of resistance change rate-temperature curves of two groups of test pieces during the heating process of the embodiment;

[0036] Fig.10 is a graph of average resistance change rate-temperature of two groups of test pieces during the heating process of the embodiment;

[0037] Fig.11 is a graph of resistance change rate-temperature curves of two groups of test pieces during the cooling process of the embodiment;

[0038] Fig.12 is a graph of average resistance change rate-temperature of two groups of test pieces during the cooling process of the embodiment;

[0039] In the figure: 1. Single-rib geogrid strip; 2. Rubber frame; 3. Paint roller; 4. Paint push rod. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in 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 embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] A method for preparing a self-deformed geotextile belt, the preparation steps are as follows: Figure 1 )include:

[0043] S1. Cutting: cutting out single-rib geogrid strips from the geogrid, retaining some geogrid transverse ribs on the single-rib geogrid strips, and keeping the width and cut of the single-rib geogrid strips uniform.

[0044] S2, conductive coating, using a roller coating mold to apply the conductive coating mixture on the single-rib geogrid strip 1, and after the coated conductive coating mixture is cured and formed, a conductive film is obtained. Figure 2 ) includes a rubber frame 2, a brush roller 3, and a brush push rod 4; the brush roller 3 is arranged above the rubber frame 2, and the brush push rod 4 is arranged on the side of the brush roller 3. The size of the rubber frame 2 is 1000mm long×15mm wide×1mm thick. During the conductive paint coating process, rubber frames of different sizes can be used to evenly control the length, width and height of the conductive paint mixture. The specific steps of conductive paint coating include:

[0045] Place the rubber frame of the roller coating mold evenly on the grid to be coated on the single-rib geogrid strip;

[0046] The electric coating mixture is applied inside the rubber frame. The electric coating mixture is a mixture of conductive coating slurry and curing agent, and the mass ratio of the conductive coating slurry to the curing agent is 10:1. The conductive coating uses a conductive polymer produced by Nanjing Dinoni Technology Co., Ltd. with carbon black and graphene as main conductive particles.

[0047] During the painting process, the painting push rod in the roller coating mold is used to push the painting roller to roll back and forth on the rubber frame 3-4 times;

[0048] After 5-10 minutes of initial curing of the electrostatic coating mixture, the rubber frame is removed, and a conductive film is obtained on the grid to be coated on the single-rib geogrid strip. Under the action of the curing agent, the conductive coating gradually solidifies and forms. The initial resistance value of the conductive film after curing begins to decrease from a high value of about 1700Ω and gradually stabilizes to about 1450Ω. At this time, a complete conductive network structure has been formed inside the conductive film. The change trend of the conductive film resistance over time is as follows Figure 3 .

[0049] Among them, in order to verify the measured value of the conductive film resistance, the FBG fiber Bragg grating sensor is pasted on the back of the geotextile belt. The sensor is arranged along the central axis of the grid strip. The FBG is appropriately pre-stretched during the layout to ensure that the grating is in a stretched state. The measuring point is protected by a 1mm plastic leather sleeve. In order to make the FBG and the grid strip firmly adhere to obtain accurate geotextile strain values, the connection between the FBG fiber Bragg grating sensing segment and the data transmission jumper is first flattened with a professional cutting knife, and then the optical fiber and the jumper are connected by a professional fusion splicer to form a data transmission path. The connection position is protected with a heat shrink tube to prevent external loads from damaging the transmission path. In order to prevent the FBG from affecting the measurement of other measuring points due to damage to a certain measuring point, a jumper is led out on both sides of the optical fiber as a spare. After the FBG sensor is fused, a red light pen is used to test the continuity, and then the demodulator is connected to check the wavelength of the measuring point to ensure that each measuring point can work normally.

[0050] S3, sealing, select the spacing distance on the surface of the conductive film, use conductive tape to make electrodes and lead out wires to form a loop as a measuring section, use a roller coating mold to evenly cover the K-704L produced by Kraft Company for waterproofing and heat insulation, and evenly spray a small amount of water on the conductive film during the drying process after the liquid silicone rubber is applied to promote the curing and molding of the liquid silicone rubber to obtain a self-induced deformation geotextile. Among them, the self-induced deformation geotextile is as follows Figure 4 shown.

[0051] Example 2 Study on the force-sensitive properties of geotextile belts

[0052] The geotextile belt prepared by the method of Example 1 was cut into a sample with a length of 200 mm, a width of 15 mm, and a thickness of 1.1 mm. The test was carried out using a universal testing machine. Before the test, the sensing geotextile belt was clamped by a fixture, the axis of the sample was aligned with the axis of the fixture, and the tensile test was set at a rate of 1 mm / min. The resistance was collected by a multimeter.

[0053] The average stress-strain curve of the geotextile belt was obtained through three sets of tensile tests, such as Figure 5 shown.

[0054] from Figure 5It can be seen that the stress-strain of the geotextile belt during the stretching process is roughly linear. The strain at break is 2.56% and the stress is 247.70MPa. The basic physical properties of the geotextile belt can be obtained from the analysis curve as shown in Table 1:

[0055] Table 1 Main physical properties of geotextile belts

[0056]

[0057] The average resistance change rate-strain curve of the geotextile belt is as follows Figure 6 shown.

[0058] Figure 6 The resistance change rate-strain is roughly linear within the 1% strain range. When the tensile strain increases, the resistance change rate increases synchronously. The fitting curve correlation coefficient is very high, 0.9992, and the fitting formula is y = 0.0292x-0.0064. When the strain is greater than 1%, a polynomial fitting is required.

[0059] Example 3 Basic sensing characteristic parameters of geotextile belt

[0060] The geotextile belt prepared by the method of Example 1 can maintain elasticity within the deformation range of the substrate. Compared with the 1% strain range of sensors such as FBG, when the grid is broken at the 2.56% strain position, the flexible conductive film still has continuous data output. The FBG and conductive film measurement time curves are shown in FIG. Figure 7 shown.

[0061] The geotextile belt is measured for 48 hours without input, and the resistance changes are as follows: Figure 8 As shown, the change value is 8.7Ω, and the change value accounts for 0.6% of the initial value. Generally, the zero drift value is often removed from the measurement result, and the resistance change rate is used The relationship with strain is that when there is no strain, ΔR is 0, and the initial value has been subtracted, that is, the final value is the ratio of the resistance increment to the initial resistance value when stable, eliminating the influence of zero drift.

[0062] Example 4

[0063] The geotextile belt prepared by the method of Example 1 has a size of 120 mm × 15 mm × 1.1 mm, and is divided into two groups of specimens, one uncoated with K-704L liquid silicone rubber and one coated with K-704L liquid silicone rubber, with 3 specimens taken from each group, for a total of 6 specimens. The temperature gradient is 5°C, and the changes in resistance of the sensing geotextile belt specimens in the heating process of 0°C to 50°C and the cooling process of 50°C to 0°C are measured respectively.

[0064] The geotextile tape samples were pasted with conductive tape according to the gauge length of 100mm. After the test started, the temperature in the heating box was kept constant and the door was closed without disturbance. The wires were uniformly led out through the exhaust holes of the heating box. The resistance change rate-temperature curves of the two groups of specimens during the heating process were obtained ( Fig. 9 ) and the average resistance change rate-temperature curve of the two groups of specimens during the heating process ( Fig.10 ).

[0065] from Fig. 9 It can be seen that the resistance of the six specimens showed an upward trend during the heating process, among which the resistance change rate of the specimen without silicone rubber coating increased faster than that of the specimen coated with silicone rubber, and the overall change rate value was greater than the latter. Fig.10 From the above, we can see that the average resistance change rate of the two groups of specimens during the heating process differs by up to 4.5%.

[0066] According to the change of resistance during the heating process, it can be seen that when the temperature is low, the internal structure of the sensor geotextile and the conductive network of carbon black and graphite are relatively stable. At this time, a certain temperature rise or fall will not destroy this stability. When the temperature increases to a certain level, conductive fillers such as carbon black and graphite will undergo their own volume expansion and thermal motion disturbance, and this effect will increase with increasing temperature. At this time, the spacing between conductive fillers that produce tunneling effects increases, and at the same time, the resistance between electrons increases, so the resistance shows an accelerated increase trend.

[0067] Obtain the resistance change rate-temperature curves of the two groups of specimens during the cooling process ( Fig.11 ) and the average resistance change rate-temperature curve of the two groups of specimens during the cooling process ( Fig.12 ).

[0068] from Fig.11 It can be seen from the figure that the cooling stage is basically the reverse process of the heating stage, and the whole process does not have much impact on the conductivity of the sensor geotextile belt. Fig.12 It can be seen that the average resistance change rate of the two groups of specimens during the cooling process differs by up to 4%. It is worth noting that compared with the specimens coated with silicone rubber, the specimens not coated with waterproof silicone rubber are more susceptible to temperature. Therefore, in actual projects, waterproof silicone rubber can achieve the dual effects of waterproofing and temperature insulation.

[0069] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0070] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a self-deformed geotextile belt, characterized in that: The preparation steps include: Cutting, cutting out single-rib geogrid strips from the geogrid, retaining some grid transverse ribs on the single-rib geogrid strips, and keeping the width and cut of the single-rib geogrid strips uniform; Conductive coating is applied by using a roller coating mold to apply an electric coating mixture to the single-rib geogrid strip, and a conductive film is obtained after the applied electric coating mixture is cured and formed; Sealing, selecting a spacing distance on the surface of the conductive film, using conductive tape to make electrodes and leading out wires to form a loop as a measuring section, and using a roller coating mold to evenly cover the conductive film with liquid silicone rubber for sealing treatment to obtain a self-inductively deformed geotextile belt.

2. The method for preparing a self-deformable geotextile belt according to claim 1, characterized in that: The electro-coating mixture is a mixture of conductive coating slurry and a curing agent.

3. The method for preparing a self-deformable geotextile belt according to claim 2, characterized in that: The mass ratio of the conductive coating slurry to the curing agent is 10:

1.

4. The method for preparing a self-deformable geotextile belt according to claim 1, characterized in that: The roller coating mold comprises a rubber frame, a brush roller and a brush push rod; the brush roller is arranged above the rubber frame, and the brush push rod is arranged on the side of the brush roller.

5. The method for preparing a self-deformable geotextile belt according to claim 3, characterized in that: During the conductive paint coating process, rubber frames of different sizes can be used to uniformly control the length, width and height of the conductive paint mixture filling.

6. The method for preparing a self-deformable geotextile belt according to claim 1, characterized in that: The specific steps of applying the conductive coating include: Place the rubber frame evenly on the grid to be coated on the single-rib geogrid strip; Apply electrocoat mixture inside the rubber frame; During the painting process, the painting push rod is used to push the painting roller to roll back and forth on the rubber frame 3-4 times; After the electro-brush coating mixture is initially cured for 5-10 minutes, the rubber frame is taken out, and a conductive film is obtained on the grid to be coated on the single-rib geogrid strip.

7. The method for preparing a self-deformable geotextile belt according to claim 1, characterized in that: The cured conductive film is evenly sprayed with water during the drying process after the liquid silicone rubber is applied.

8. A self-deformable geotextile belt, characterized in that: The geotextile belt is prepared by the method for preparing a self-deformed geotextile belt as described in any one of claims 1 to 7.

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