Multifunctional composite waterproof blanket suitable for roadbed engineering

Abstract

This invention discloses a multifunctional composite waterproof blanket suitable for roadbed engineering, comprising, from top to bottom: anti-slip protrusions, a first waterproof layer, a leakage monitoring layer, a second waterproof layer, a drainage layer, a protective layer, drainage lines, and anti-slip protrusions. The waterproof layer is composed of a uniformly mixed superhydrophobic soil and fiber, sandwiched between two layers of non-woven geotextile at a preset compaction degree. The drainage layer consists of an upper layer of high-absorption geotextile, absorbent yarns, and a lower layer of permeable geotextile. This multifunctional composite waterproof blanket for roadbed engineering addresses the problems of existing waterproof blankets' inability to effectively block water migration paths and quickly drain accumulated water in water-rich roadbed engineering, as well as their inability to monitor water leakage and waterproof material damage in real time, leading to frequent and accelerated deterioration of roadbed defects and difficulty in ensuring the quality of drainage and waterproofing in engineering projects.

Description

Technical Field

[0001] This solution belongs to the field of waterproof blanket technology, specifically a multifunctional composite waterproof blanket suitable for water-rich roadbed engineering. Background Technology

[0002] In roadbed engineering, the migration and accumulation of moisture in the soil increases the internal water content and humidity of the roadbed, severely affecting its strength and deformation characteristics, leading to engineering defects such as roadbed instability, pavement cracking, and localized collapse. Therefore, controlling the water content of the roadbed soil, intelligently monitoring water seepage and damage to the waterproofing blanket, and blocking the migration path of groundwater from water-rich strata to the roadbed are of great significance for controlling roadbed defects and ensuring the safety and smoothness of the railway line.

[0003] Currently, bentonite geotextile blankets (GCLs) and composite geomembranes ("two layers of geotextile and one layer of geomembrane") are widely used in roadbed engineering. Bentonite geotextile blankets are blanket-like waterproofing materials made by uniformly fixing sodium-based bentonite particles or powder between two layers of geotextile through processes such as needle punching and adhesive bonding. Bentonite geotextile blankets typically exhibit excellent seepage prevention performance in fresh water or deionized water. When applied to complex environments, their expansion index and viscosity decrease significantly, while their permeability coefficient increases, and their seepage prevention performance fails to meet requirements. Due to their inherent properties, they also exhibit defects such as poor peelability, reduced shear strength after hydration, and uneven expansion and damage caused by hydration expansion reactions before or during installation. Furthermore, composite geomembranes, due to their closed structure, can experience a "pot lid effect," causing a large accumulation of moisture near the waterproof layer. They are also susceptible to creep caused by air bubbles, punctures, ruptures, and degradation, leading to a significant decrease in the waterproof and seepage prevention performance of the waterproof layer. In addition, commonly used drainage geosynthetics can only show good drainage effect in saturated soil, but they are difficult to drain water in unsaturated soil and cannot eliminate subgrade diseases. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a multifunctional composite waterproof blanket suitable for roadbed engineering. It uses superhydrophobic soil with excellent waterproof and seepage-proof properties and fibers to be uniformly mixed as the core waterproof material of the waterproof layer, and is designed into a blanket shape in combination with a leakage monitoring layer, a drainage layer and other additional layers for easy engineering application.

[0005] To achieve the aforementioned technical objectives, the multifunctional composite waterproof blanket proposed in this application comprises, from top to bottom, anti-slip ridges, a first waterproof layer, a leakage monitoring layer, a second waterproof layer, a drainage layer, a protective layer, hydrophobic lines, and anti-slip ridges. The first waterproof layer has anti-slip ridges. The first and second waterproof layers consist of modified soil sandwiched between two layers of non-woven geotextile at a preset compaction degree. The modified soil is composed of a uniform mixture of superhydrophobic soil and fibers. The leakage monitoring layer is composed of non-metallic conductive geotextile, with its upper surface bonded to the lower surface of the first waterproof layer and its lower surface bonded to the upper surface of the second waterproof layer. The drainage layer consists of an upper layer of high-absorption geotextile, absorbent yarns, and a lower layer of permeable soil. The geotextile is composed of a high-absorption geotextile. The weft direction is made of polyester core-absorbing yarns with irregular cross-sections and reinforced polyester filaments, woven together by polyester filaments in the warp direction. The drainage yarns are composed of several polyester yarns with nanofibers attached to their surfaces, each yarn formed by interlacing polyester core-absorbing fibers. The surface of the polyester core-absorbing fibers has micron-level grooves along its axis. The protective layer is made by filling several natural soil particles between the lower permeable geotextile and the non-woven geotextile layer. The protective layer has anti-slip protrusions. The first waterproof layer uses hydrophobic threads to stitch the two layers of non-woven geotextile to the modified soil. The second waterproof layer, drainage layer, and protective layer are stitched together using hydrophobic threads.

[0006] In one embodiment of the above technical solution, the anti-slip ridge is made by filling a hollow rubber strip with EVA foam material.

[0007] In one embodiment of the above technical solution, the anti-slip protrusion is in the shape of a spike.

[0008] In one embodiment of the above technical solution, the hydrophobic line is prepared by impregnating or coating a high-strength nylon wire with a hydrophobic solution and then drying or curing it.

[0009] In one embodiment of the above technical solution, the proportion of polyester core-absorbing fibers in the high-absorption geotextile is not less than 25%, and the spacing between weft polyester core-absorbing fiber bundles is not less than 5mm.

[0010] The method of using any of the above-mentioned multifunctional composite waterproof blankets is as follows: when laying the waterproof blanket, the polyester core absorbent yarn with drainage function in the weft direction of the drainage layer is aligned with the cross section direction of the roadbed, and the two ends of the drainage layer are exposed to the roadbed for a predetermined length.

[0011] The beneficial technical effects of this solution are as follows: The waterproof blanket in this solution is particularly suitable for water-rich strata, effectively blocking the replenishment of the roadbed by groundwater in water-rich strata, blocking the migration path of water, and simultaneously draining the water accumulated in the roadbed quickly, preventing the "boiler effect" and ensuring that the roadbed soil remains in a low moisture content state for a long time. Furthermore, the composite waterproof blanket can monitor water leakage and damage to the waterproof blanket in real time during roadbed engineering, and accurately locate leakage points, ensuring the performance of the waterproof blanket throughout its entire life cycle, effectively inhibiting the expansion and deterioration of roadbed diseases, and extending the service life of the roadbed. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a structural diagram of a waterproof blanket in one embodiment.

[0014] Figure 2 This is a schematic diagram of a drainage layer in one embodiment.

[0015] Figure 3 This is a schematic diagram of an anti-slip ridge / protrusion in one embodiment. Detailed Implementation

[0016] As is known from the background technology, existing waterproofing and drainage materials are difficult to maintain good waterproofing and drainage performance in water-rich roadbed projects. They cannot effectively block the migration path of water and quickly drain the water accumulated in the roadbed. At the same time, they cannot monitor water leakage and damage to waterproofing materials in real time, resulting in frequent roadbed diseases and accelerated deterioration, making it difficult to guarantee the quality of waterproofing and drainage in the project.

[0017] Based on this, this solution proposes a multifunctional composite waterproof blanket suitable for water-rich roadbed engineering. This waterproof blanket can effectively control the moisture content in the roadbed and monitor water leakage and blanket damage in real time, ensuring that the roadbed soil remains in a dry or low-moisture state for a long period. Of course, the waterproof blanket in this solution is also applicable to other roadbeds.

[0018] The following provides a clear and complete description of how the technical solution of this case is implemented. Obviously, the described implementation methods are only a part of the implementation methods of this case, and not all of them. Based on the implementation methods in this case, all other implementation methods obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0019] See Figure 1The waterproof blanket structure shown comprises, from top to bottom: anti-slip raised strips 1, a first waterproof layer 3-1, a leakage monitoring layer 4, a second waterproof layer 3-2, a drainage layer 5, a protective layer 6, a hydrophobic line 7, and anti-slip raised strips 8. Each layer is described in detail below.

[0020] (1) Anti-slip raised strip 1

[0021] Multiple anti-slip raised strips 1 are provided on the upper surface of the waterproof blanket body. These anti-slip raised strips 1 are made by filling hollow rubber strips 1-1 with EVA foam material 1-2. The two work together to prevent slippage, such as... Figure 3 As shown in the left-hand diagram. The spacing between the anti-slip protrusions 1 can be equal or unequal.

[0022] The anti-slip ridge 1 has excellent cushioning performance and shock resistance. Setting the anti-slip ridge can increase the coefficient of friction, ensuring protection of the main surface while providing stable friction for the workers' feet, thus improving construction safety.

[0023] (2) Non-woven geotextile 2

[0024] The nonwoven geotextile 2 is made of polypropylene fiber, with a unit area mass ≥200g / m². 2 It has excellent tensile strength and durability, and can effectively fix and isolate the superhydrophobic soil particles, prevent the loss of superhydrophobic soil particles and mixing with the surrounding soil, and ensure the long-term stable waterproof effect of the waterproof blanket.

[0025] (3) Modified soil waterproofing layer 3

[0026] The modified soil waterproof layer 3 is divided into a first waterproof layer 3-1 and a second waterproof layer 3-2. It is composed of modified soil sandwiched between two layers of non-woven geotextile 2 with a certain degree of compaction. This can solve the problems of existing sodium-based bentonite waterproof blankets, which have poor peelability, reduced shear strength after hydration, leakage through holes, uneven expansion and damage caused by hydration expansion reaction when exposed to water before or during installation, thus damaging or failing the integrity of the seepage prevention system. The modified soil is composed of a uniform mixture of superhydrophobic soil and fiber.

[0027] ①Superhydrophobic soil

[0028] The superhydrophobic soil is a new type of waterproof material with excellent waterproof and seepage-proof properties, prepared by mixing natural soil (natural soil or engineering waste soil) with hydrophobic modification materials (hydrophobic agents already available on the market). For example, this product uses CN01C soil superhydrophobic emulsion as a hydrophobic agent. Simply add the emulsion to the soil sample according to the optimal concentration and the optimal amount of hydrophobic agent, mix it thoroughly, and then wait for the modified soil sample to dry.

[0029] This application's superhydrophobic soil is not limited to the method or hydrophobic agent mentioned above; commercially available or researched hydrophobic agents can be used, such as polydimethylsiloxane (PDMS), octadecyl primary amine, and SHOIP (superhydrophobic polymer). The ultimate goal is to modify the soil from hydrophilic to superhydrophobic through modification treatment, exhibiting extreme water-repellent properties similar to the "lotus leaf effect," achieving zero permeability of the waterproof layer. The superhydrophobic soil has a particle size of 5~50μm, a static contact angle with water ≥150°, and a roll-off angle ≤10°.

[0030] ② Fiber

[0031] The fibers are selected from at least one of basalt fiber, polypropylene fiber, polyvinyl alcohol (PVA) fiber, and sisal fiber. After the fibers are uniformly mixed into the superhydrophobic soil, the fibers will come into contact with the soil to generate friction and interlocking forces. In addition, multiple fibers form a three-dimensional network structure to constrain and fix the superhydrophobic soil particles, preventing the movement of the superhydrophobic soil particles and improving the integrity and physical and mechanical properties of the soil.

[0032] (4) Leakage monitoring layer 4

[0033] The non-metallic conductive geotextile of the leakage monitoring layer 4 gives it excellent electrical properties and chemical corrosion resistance. By monitoring the changes in the resistance of the conductive geotextile in real time, it can monitor water leakage and damage to the waterproof blanket, accurately locate leakage points, ensure the performance of the waterproof blanket throughout its entire life cycle, avoid damage to the roadbed waterproof layer, and extend the service life of the roadbed.

[0034] In one embodiment, the non-metallic conductive geotextile is made by blending non-metallic conductive fibers with ordinary fibers. The non-metallic conductive fibers are prepared by adding one or more of carbon nanotubes, graphene, and superconducting carbon black to a polymer. The amount of non-metallic conductive fibers added to the leakage monitoring layer 4 is 35%–100%, and its surface resistivity is <1×10⁻⁶. 5 Ω•m. The leakage monitoring layer 4 is fixed between the upper and lower modified soil waterproof layers by adhesive bonding.

[0035] (5) Drainage layer 5

[0036] like Figure 2 As shown, the drainage layer 5 is composed of an upper high-absorption geotextile 5-1, a drainage yarn 5-2, and a lower permeable geotextile 5-3.

[0037] ① High-absorption geotextile 5-1

[0038] The high-absorption geotextile 5-1 is composed of polyester core-absorption yarn with irregular cross-section and reinforced polyester filaments in the weft direction, and is woven into a whole by polyester filaments in the warp direction.

[0039] In one embodiment, two polyester core absorbent yarns are arranged with a polyester filament spaced apart in the weft direction, and are woven together with the warp polyester filaments in a regular pattern. The warp and weft arrangement of the filament fibers forms a stress-bearing skeleton, which plays a reinforcing role. The polyester core absorbent yarns play a role in absorbing and draining water by relying on the capillary force generated by the micron-level fiber grooves.

[0040] In one embodiment, the proportion of the polyester core absorbent fiber in the high-absorption geotextile 5-1 should not be less than 25%, and the spacing between the weft polyester core absorbent fiber bundles should not be less than 5 mm, so as to ensure the water absorption and drainage performance of the high-absorption geotextile 5-1.

[0041] The high-absorption geotextile 5-1 is a transverse drainage geotextile. When laid, the polyester core absorbent yarn with drainage function in the weft direction is consistent with the cross section direction of the roadbed.

[0042] ② Absorbent and drainable yarn 5-2

[0043] The absorbent yarn 5-2 is composed of several polyester yarns with nanofibers attached to their surfaces, achieving excellent absorbency and drainage capabilities. Each polyester yarn is formed by interlacing polyester wicking fibers, and the surface of these fibers has micron-sized grooves along its axis. This cross-sectional shape gives the wicking fibers a larger specific surface area and capillary force. The grooves on their surface form drainage channels with a diameter smaller than the gaps between soil particles, generating a wicking effect that absorbs moisture from unsaturated soil and discharges it along drainage ditches or pipes.

[0044] The nanofibers are formed by stretching and refining melted polyacrylonitrile (PAN) using electrospinning technology and a strong electric field. They possess a more minute pore structure, resulting in superior macroscopic hydrophilic and hygroscopic properties. The nanomaterials are coated onto each strand of polyester yarn, with a coating thickness of 1 / 6 of the cross-sectional dimension of the polyester yarn. The drainage channels of the absorbent yarn 5-2 should be placed laterally in the roadbed, aligned with the cross-sectional direction of the roadbed.

[0045] In one embodiment, the polyester yarn is formed by interlacing polyester wicking fibers and has a diameter of about 1 mm; the cross-sectional diameter of each wicking fiber is about 10 μm, and there are four deep grooves on the surface axially, each groove having a diameter of about 5 μm.

[0046] ③ Permeable geotextile 5-3

[0047] The permeable geotextile 5-3 has good permeability and filtration properties, and its unit area mass should be no less than 200g / m². 2 .

[0048] It should be noted that the proportion of polyester core fibers in high-absorption geotextile, the spacing between weft polyester core fiber bundles, the diameter of polyester yarn, the cross-sectional diameter of core fibers, the number of grooves, the diameter of grooves, the thickness of nanomaterial coating, and the quality of permeable geotextile mentioned above can be adapted to achieve the same purpose or to improve the corresponding technical effect.

[0049] The leakage monitoring layer 4 enables real-time monitoring of water leakage and waterproof blanket damage in roadbed engineering, and allows for precise location of leakage points, ensuring the performance of the waterproof blanket throughout its entire life cycle. The first waterproof layer 3-1 and the second waterproof layer 3-2 effectively block the migration path of water, and the drainage layer 5 promptly drains the water accumulated in the roadbed, preventing the "boiler effect" and effectively inhibiting the expansion and deterioration of roadbed defects, improving the quality of drainage and waterproofing, and extending the service life of the roadbed. The protective layer can prevent damage to the main body of the waterproof blanket.

[0050] (6) Protective layer 6

[0051] The protective layer 6 is prepared by filling a number of natural soil particles between the lower permeable geotextile 5-3 and the non-woven geotextile layer 2. The natural soil particles can be natural soil or engineering waste soil, wherein the natural soil particles are at least one of silt, silty sand or silty clay.

[0052] By setting a protective layer 6 at the bottom of the waterproof blanket body, the protective layer 6 can isolate the waterproof blanket body from the substrate, preventing protruding gravel and other debris on the base layer from scratching the waterproof blanket body and affecting the waterproof effect of the waterproof blanket body.

[0053] (7) Drainage line 7

[0054] To facilitate the engineering application and transportation of waterproof blankets, other layers need to be combined into a single blanket shape through processes such as sewing. To effectively prevent moisture leakage along the holes and seams, in one embodiment, a hydrophobic thread 7 is used for sewing. The hydrophobic thread 7 is prepared by impregnating or coating high-strength nylon thread with a hydrophobic solution and then drying or curing it. The hydrophobic agent can firmly adhere to the surface of the thread, forming a high-strength sewing thread with excellent waterproof performance.

[0055] In one embodiment, the first waterproof layer 3-1 is stitched together with two layers of non-woven geotextile 2 and modified soil using hydrophobic thread 7, and the second waterproof layer 3-2, drainage layer 5 and protective layer 6 are stitched together as one unit using hydrophobic thread 7.

[0056] (8) Anti-slip protrusions 8

[0057] Multiple spike-shaped anti-slip protrusions 8 are provided on the lower surface of the protective layer 6. These spike-shaped anti-slip protrusions 8 can be inserted into the base layer, allowing the waterproof blanket to be better fixed and bonded to the base layer, increasing the overall friction of the waterproof blanket and improving the contact stability of the contact surface. The anti-slip protrusions 8 can be spaced evenly or unequally.

[0058] In one embodiment, the spike is specifically rhomboid in shape, such as... Figure 3 As shown in the diagram on the right.

[0059] Figure 1 One method of using the waterproof blanket with the structure shown is as follows: the waterproof blanket is laid transversely to the roadbed at a certain depth, parallel to the direction of the absorbent and drainable yarns 5-2, with the waterproof part facing upwards and the drainable part facing downwards. During installation, both ends of the drainage layer 5 protrude from the roadbed by a predetermined length, exposed to the air for moisture evaporation. During use, the absorbent and drainable yarns 5-2 in the drainage layer 5 utilize their high capillary force to continuously absorb moisture through wicking and discharge it to the outside of the soil along internal micro-grooves or pipes, ensuring that the roadbed soil remains in a low moisture content state for a long period, thus solving a series of problems caused by changes in roadbed moisture content.

[0060] Under the above usage, the construction method of the multi-functional composite waterproof blanket for roadbed is briefly described as follows: (1) Clean the plant roots, boulders, wires and other sharp objects in the laying base to avoid damage to the composite waterproof blanket due to external factors; (2) Compact and level the laying base to ensure that the base is tight and uniform, the soil is firm and there is no obvious bulge (such as the bulge height is greater than the predetermined height); (3) Lay the roadbed composite waterproof blanket on the surface of the base and insert the anti-slip protrusion 8 into the laying base layer so that the waterproof blanket and the laying base can be better fixed and combined, and at the same time expose the end of the drainage layer 5 on both sides of the roadbed at a certain length.

[0061] In one embodiment, the waterproof blanket comprises a first waterproof layer 3-1, a leakage monitoring layer 4, a second waterproof layer 3-2, a drainage layer 5, and a protective layer 6. Compared to other waterproof materials that only have the single function of water blocking or drainage, this waterproof blanket is a multifunctional composite waterproof blanket. Its first waterproof layer 3-1, leakage monitoring layer 4, second waterproof layer 3-2, and drainage layer 5 enable it to actively drain excess water from the unsaturated roadbed, effectively block water intrusion, and achieve full-section moisture monitoring of the roadbed. The protective layer 6 prevents damage to the main body of the waterproof blanket.

[0062] In one embodiment, the waterproof blanket may consist of a first waterproof layer 3-1, a leakage monitoring layer 4, and a second waterproof layer 3-2. A protective layer 6 may or may not be present depending on the installation environment. In this embodiment, the waterproof blanket is used for isolation above or below and for leakage monitoring.

[0063] In one embodiment, the waterproof blanket may consist only of a drainage layer 5, with or without a protective layer 6 depending on the laying environment. During use, the laying direction of the drainage layer 5 is determined according to the application scenario. In this embodiment, the moisture content of the laying site is controlled through the drainage function of the waterproof blanket.

[0064] In one embodiment, the waterproof blanket can be used in canal waterproofing projects. The waterproof blanket may consist of one or more layers of modified soil waterproofing material, laid beneath the surface lining of the canal, evenly distributed longitudinally along the canal. For transverse laying, the length should be sufficient to cover the entire cross-section of the trench. In this embodiment, the waterproof blanket effectively blocks the seepage channels of water from the canal into the surrounding foundation, preventing water leakage problems in long-distance water conveyance projects.

[0065] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of the invention is defined by the appended claims.

Claims

1. A multifunctional composite waterproof blanket, characterized in that: The waterproof blanket comprises, from top to bottom, anti-slip raised strips, a first waterproof layer, a leakage monitoring layer, a second waterproof layer, a drainage layer protective layer, hydrophobic lines, and anti-slip raised strips; The first waterproof layer has anti-slip ridges. The first and second waterproof layers are formed by sandwiching modified soil between two layers of non-woven geotextile according to a preset compaction degree. The modified soil is formed by uniformly mixing superhydrophobic soil and fiber. The leakage monitoring layer is made of non-metallic conductive geotextile, with its upper surface bonded to the lower surface of the first waterproof layer and its lower surface bonded to the upper surface of the second waterproof layer. The drainage layer consists of an upper high-absorption geotextile, drainage yarns, and a lower permeable geotextile. The weft direction of the high-absorption geotextile is composed of polyester core-absorption yarns with irregular cross-sections and reinforced polyester filaments, and is woven into a whole by polyester filaments in the warp direction. The drainage yarns are made of several polyester yarns with nanofibers attached to the surface, and each polyester yarn is formed by the interlacing of polyester core-absorption fibers. The surface of the polyester core-absorption fibers has micron-level grooves in the axial direction. The protective layer is made by filling a number of natural soil particles between the lower permeable geotextile and the non-woven geotextile layer, and the protective layer has anti-slip protrusions. The first waterproof layer uses a hydrophobic thread to stitch two layers of non-woven geotextile to the modified soil, and the second waterproof layer, drainage layer and protective layer are stitched together as one unit using a hydrophobic thread.

2. The multifunctional composite waterproof blanket according to claim 1, characterized in that, The anti-slip ridge is made of hollow rubber strip filled with EVA foam material.

3. The multifunctional composite waterproof blanket according to claim 1, characterized in that, The anti-slip protrusions are shaped like sharp nails.

4. The multifunctional composite waterproof blanket according to claim 1, characterized in that, The hydrophobic line is prepared by impregnating or coating high-strength nylon wire with a hydrophobic solution and then drying or curing it.

5. The multifunctional composite waterproof blanket according to claim 1, characterized in that, The proportion of polyester core fibers in the high-absorption geotextile is not less than 25%, and the spacing between weft polyester core fiber bundles is not less than 5 mm.

6. A method of using the multifunctional composite waterproof blanket according to any one of claims 1-5, characterized in that, When laying the waterproof blanket, the polyester core absorbent yarn with drainage function in the weft direction of the drainage layer should be aligned with the cross section direction of the roadbed, and both ends of the drainage layer should be exposed beyond the roadbed by a predetermined length.

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