Fire resistant thermal barrier jacket for bridge cables

Abstract

The application relates to the field of bridge cable protection, and discloses a fireproof and heat-insulating sheath for bridge cable, which comprises an upper half sheath, a lower half sheath and multiple sets of locking assemblies, the upper half sheath and the lower half sheath are symmetrical and have the same shape and size; the upper half sheath comprises an upper half ring part and an upper half circular platform part, and the upper half circular platform part is fixedly connected to the left end of the upper half ring part. The application has the following advantages and effects: the in-situ automatic repair of the internal micro-cracks and interlayer void defects of the fireproof and heat-insulating sheath can be realized, the service life of the fireproof and heat-insulating sheath is prolonged, the fireproof and heat-insulating property and safety of the bridge cable protection are improved, the fireproof and heat-insulating sheath and the bridge cable can be detected in all directions, the internal temperature of the sheath can be collected in real time, the fire safety of the bridge cable is improved, and the single sheath can be individually disassembled and replaced, so that the damaged part of the sheath can be individually replaced, and the maintenance cost and the on-site construction difficulty are greatly reduced.

Description

Technical Field

[0001] This application relates to the field of bridge cable protection technology, and in particular to a fire-resistant and heat-insulating sheath for bridge cables. Background Technology

[0002] With the continuous increase in traffic flow, the frequency of road transport vehicles carrying hazardous chemicals has increased significantly, and bridge fire accidents caused by vehicles have increased year by year. The high-strength steel wires inside the bridge cables have poor high-temperature resistance. If a vehicle fire occurs on the bridge deck, the high temperature will rapidly reduce the mechanical strength of the steel wires, which can easily lead to bridge safety accidents. Therefore, it is necessary to cover the outside of the bridge cables with fire-resistant and heat-insulating sheaths for protection.

[0003] In existing technologies, most fire-resistant and heat-insulating sheaths used for bridge cables on the market are made of multi-layer functional materials. Although they can achieve heat insulation, flame retardancy, and outdoor protection to a certain extent, at least the following shortcomings have been found in actual use: During long-term use, due to the continuous reciprocating vibration and bending of bridge cables under the action of wind and vehicle loads, the fire-resistant and heat-insulating layer of the sheath is prone to micron-level microcracks. At the same time, interlayer delamination and gaps are prone to occur between the fire-resistant and heat-insulating layer and the inner bonding layer and the outer sealing protective layer, forming thermal bridge channels. The existing bridge cable sheaths do not have a self-healing structure. After cracks and interlayer gaps occur, they cannot be filled and sealed by themselves, which makes it easy for rainwater and high-temperature smoke to continuously penetrate from the gaps. On the one hand, this greatly reduces the overall fire-resistant and heat-insulating performance of the sheath, and on the other hand, it corrodes the original protective layer and internal steel wires of the cable, shortening the service life of the sheath and the cable. Defects can only be detected and dealt with manually on a regular basis. Microcracks are difficult to be detected and dealt with in time, resulting in a large workload for maintenance and a high risk of protection failure. Therefore, we propose a fire-resistant and heat-insulating sheath for bridge cables to solve the above problems. Summary of the Invention

[0004] The purpose of this application is to provide a fire-resistant and heat-insulating sheath for bridge cables, which can automatically repair micro-cracks and interlayer voids inside the sheath in situ, extend the service life of the sheath, improve the fire resistance, heat insulation and safety of the bridge cable protection, and enable all-round temperature detection of the fire-resistant and heat-insulating sheath and bridge cable, real-time acquisition of the internal temperature of the sheath, thereby improving the fire safety of the bridge cable. Moreover, each section of the sheath can be disassembled and replaced individually, which makes it easy to replace the damaged parts of the sheath separately, greatly reducing maintenance costs and on-site construction difficulties.

[0005] The above-mentioned technical objective of this application is achieved through the following technical solution: a fire-resistant and heat-insulating sheath for bridge cables, comprising an upper sheath, a lower sheath, and multiple sets of locking components. The upper and lower sheaths are identical in shape and size and symmetrically arranged. The upper sheath includes an upper ring and an upper truncated cone, the upper truncated cone being fixedly connected to the left end of the upper ring, and the upper ring and the upper truncated cone are integrally formed. The lower sheath includes a lower ring and a lower truncated cone, the lower truncated cone being fixedly connected to the left end of the lower ring, and the lower ring and the lower truncated cone are integrally formed. Multiple sets of locking components are sleeved on the upper and lower sheaths for locking and fixing the joined upper and lower sheaths. One set of locking components is used to lock and fix the joined upper and lower truncated cones, and the other sets of locking components are used for... The upper and lower rings are locked and fixed together. The upper and lower sheaths, from the inside out, each include an anti-slip buffer layer, a fire-resistant and heat-insulating main layer, a sealing fire-resistant and gas-proof layer, and a weather-resistant protective outer layer. The fire-resistant and heat-insulating main layer is fixedly connected to the outer surface of the anti-slip buffer layer, the sealing fire-resistant and gas-proof layer is fixedly connected to the outer surface of the fire-resistant and heat-insulating main layer, and the weather-resistant protective outer layer is fixedly connected to the outer surface of the sealing fire-resistant and gas-proof layer. Several self-healing microcapsules are implanted inside the fire-resistant and heat-insulating main layer. The self-healing microcapsules are used to automatically repair micro-cracks on the fire-resistant and heat-insulating main layer, as well as to automatically repair the peeling interfaces between the fire-resistant and heat-insulating main layer and the anti-slip buffer layer and the sealing fire-resistant and gas-proof layer. A flexible fiber optic temperature sensor is installed between the sealing fire-resistant and gas-proof layer and the fire-resistant and heat-insulating main layer. The flexible fiber optic temperature sensor is arranged in a serpentine pattern.

[0006] A further provision of this application is that the self-healing microcapsule comprises a spherical shell and a high-temperature resistant elastic sealing and repairing adhesive, wherein the high-temperature resistant elastic sealing and repairing adhesive fills the interior of the spherical shell.

[0007] A further feature of this application is that: a serpentine groove is formed on the side surface of the sealed fire-resistant and gas-proof layer near the fire-resistant and heat-insulating main layer; a flexible fiber optic temperature sensor is adhered and fixed in the serpentine groove by a high-temperature resistant flexible coupling adhesive; the flexible fiber optic temperature sensor is in contact with the surface of the fire-resistant and heat-insulating main layer; both ends of the flexible fiber optic temperature sensor extend beyond the sealed fire-resistant and gas-proof layer; a female connector is fixedly connected to the left end of the sealed fire-resistant and gas-proof layer; and a male connector is fixedly connected to the right end of the sealed fire-resistant and gas-proof layer, with the male connector and female connector being compatible.

[0008] A further feature of this application is that: a semi-annular partition is fixedly connected to the right end of both the upper and lower semi-annular portions, the two ends of the two semi-annular partitions abut against each other, and the two semi-annular partitions are integrally formed with the corresponding anti-slip buffer bonding layer, with the male connector located on the outside of the semi-annular partition.

[0009] A further feature of this application is that: a semi-annular heat-insulating sealing strip 1 is fixedly connected to the outer wall of the right end of both the upper and lower semi-annular portions, and a semi-annular heat-insulating sealing strip 2 is fixedly connected to the inner wall of both the upper and lower semi-truncated portions, wherein the inner diameter of the ring formed by the two semi-annular heat-insulating sealing strips 1 is the same as the inner diameter of the ring formed by the two semi-annular heat-insulating sealing strips 2.

[0010] The further configuration of this application is as follows: each of the multiple locking components includes an upper locking ring and a lower locking ring. The upper locking ring is fixedly connected to the outer surface of the upper sheath, and the lower locking ring is fixedly connected to the outer surface of the lower sheath. Both ends of the bottom of the upper locking ring are fixedly connected to an upper connecting block, and both ends of the top of the lower locking ring are fixedly connected to a lower connecting block. The two lower connecting blocks are detachably connected and fixed to the corresponding upper connecting blocks.

[0011] A further configuration of this application is: the upper connecting block and the upper half locking ring are integrally formed, and the lower connecting block and the lower half locking ring are integrally formed.

[0012] A further feature of this application is that: the bottom of each of the two upper connecting blocks is provided with a positioning groove, and the top of each of the two lower connecting blocks is fixedly connected with a positioning protrusion, and the two positioning protrusions are slidably installed in the corresponding positioning grooves.

[0013] The further configuration of this application is as follows: each of the two upper connecting blocks has a locking bolt threaded through it; each of the two lower connecting blocks has a through hole; the bottom end of each of the two locking bolts passes through the corresponding through hole; each of the two locking bolts has a damping washer movably fitted on it; the two damping washers abut against the bottom of the corresponding lower connecting block; and each of the two locking bolts has a locking nut threaded on it; the two locking nuts abut against the bottom of the corresponding damping washer.

[0014] A further feature of this application is that the bottom two sides of the upper sheath are provided with mating grooves, and the top two sides of the lower sheath are fixedly connected with sealing protrusions, with the two sealing protrusions slidably installed in the corresponding mating grooves.

[0015] This application includes at least one of the following beneficial technical effects:

[0016] 1. This application adopts a symmetrical split-type fire-resistant and heat-insulating sheath composed of an upper sheath, a lower sheath, and multiple sets of locking components. It does not require cutting or dismantling the bridge cable and can be directly wrapped and installed from the outside of the cable, which greatly reduces the difficulty of on-site construction. Furthermore, each section of the sheath can be disassembled and replaced individually, and there is no need to remove the whole structure if there is local damage in the future, resulting in lower maintenance costs.

[0017] 2. The design of this application consists of an upper and lower sheath composed of an anti-slip buffer bonding layer, a fire-resistant and heat-insulating main layer, a sealing fire-resistant and gas-proof layer, and a weather-resistant protective outer layer. It can achieve effective fire resistance and heat insulation, and can provide comprehensive protection for bridge cables. When a fire occurs on the bridge, it can effectively isolate high temperatures, protect the internal mechanical properties of the steel cables from rapid decay, and prevent the bridge from collapsing due to cable failure.

[0018] 3. This application designs a fire-resistant and heat-insulating main layer with uniformly dispersed self-healing microcapsules. When long-term wind vibration, bending, and interlayer shearing of bridge cables cause micron-level microcracks in the fire-resistant and heat-insulating main layer, or when the interface between the fire-resistant and heat-insulating main layer and the anti-slip buffer bonding layer cracks or interlayer voids occur, or when the interface between the fire-resistant and heat-insulating main layer and the sealing fire-resistant and gas-proof layer cracks or interlayer voids occur, the fire-resistant and heat-insulating sheath can achieve in-situ automatic repair of microcracks and interlayer void defects. Moreover, the automatically repaired area is resistant to high temperature, weathering, and vibration fatigue, which greatly extends the service life of the fire-resistant and heat-insulating sheath, significantly improves the fire resistance, heat insulation, and safety of bridge cable protection, and solves the problems of delamination, cracks, thermal bridging, leakage, and protection failure caused by bridge cable vibration.

[0019] 4. The self-healing microcapsule designed in this application consists of a spherical shell and a high-temperature resistant elastic sealing and repairing adhesive. The self-healing microcapsule can be stable and leak-free at room temperature, and the spherical shell will only rupture when stress is generated by microcracks or interlayer peeling.

[0020] 5. This application incorporates flexible fiber optic temperature sensors arranged in a serpentine pattern inside both the upper and lower sheaths, which can fully cover the entire length of the fire-resistant and heat-insulating sheath, enabling all-around temperature detection of the fire-resistant and heat-insulating sheath and bridge cables, with no blind spots, and real-time acquisition of the internal temperature of the sheath.

[0021] 6. This application, through the design of male and female connectors, enables the series connection of optical signals from flexible fiber optic temperature sensors when splicing multiple fire-resistant and heat-insulating sheaths, ensuring continuous temperature monitoring of the entire bridge cable protection section. It can capture local high-temperature anomalies before open flames form, accurately locate fire risk areas, achieve accurate early temperature monitoring of fires, accurately locate high-temperature and fire areas, and improve the fire safety of bridge cables. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of this application;

[0023] Figure 2 This is a bottom-view three-dimensional structural diagram of the upper sheath in this application;

[0024] Figure 3 This is a right-view stereoscopic structural diagram of the upper sheath in this application;

[0025] Figure 4This is a front-view three-dimensional structural diagram of the lower half of the sheath in this application;

[0026] Figure 5 This is a top-view three-dimensional structural diagram of the lower half of the sheath in this application;

[0027] Figure 6 This is a cross-sectional three-dimensional structural schematic diagram of this application;

[0028] Figure 7 This is a cross-sectional three-dimensional structural diagram of the fire-resistant and heat-insulating main layer in this application;

[0029] Figure 8 This is a cross-sectional view of the self-healing microcapsule in this application;

[0030] Figure 9 This is a three-dimensional structural diagram of the sealed fire-retardant air-barrier layer in this application;

[0031] Figure 10 This is a three-dimensional structural diagram of the locking component in this application;

[0032] Figure 11 This is a three-dimensional structural diagram of the upper locking ring in this application;

[0033] Figure 12 This is a three-dimensional structural diagram of the lower locking ring in this application;

[0034] Figure 13 This is a three-dimensional structural diagram of the splicing and locking state of the two sets of upper and lower sheaths in this application;

[0035] Figure 14 yes Figure 13 A front view sectional view of the three-dimensional structure;

[0036] Figure 15 yes Figure 14 A magnified structural diagram of part A in the middle;

[0037] Figure 16 This is a three-dimensional structural diagram of the application in its usage state.

[0038] In the diagram, 1. Upper sheath; 101. Upper ring; 102. Upper frustum; 2. Lower sheath; 201. Lower ring; 202. Lower frustum; 3. Connecting groove; 4. Sealing protrusion; 5. Locking assembly; 501. Upper locking ring; 502. Lower locking ring; 503. Upper connecting block; 5031. Positioning groove; 504. Lower connecting block; 5041. Through hole; 505. Positioning protrusion; 506. Locking bolt; 507. Damping washer; 508, Locking nut; 6, Anti-slip buffer bonding layer; 7, Fire-resistant and heat-insulating main layer; 8, Sealing, fire-resistant, and gas-proof layer; 9, Weather-resistant protective outer layer; 10, Self-healing microcapsule; 1001, Spherical shell; 1002, High-temperature resistant elastic sealing and repair adhesive; 11, Flexible fiber optic temperature sensor; 12, Female connector; 13, Male connector; 14, Semi-annular partition; 15, Semi-annular heat-insulating sealing strip one; 16, Semi-annular heat-insulating sealing strip two. Detailed Implementation

[0039] The technical solution of this application will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0040] First Embodiment

[0041] See Figures 1-16In the first embodiment of this application, the fire-resistant and heat-insulating sheath for bridge cables includes an upper sheath 1, a lower sheath 2, and multiple sets of locking components 5. The upper sheath 1 and the lower sheath 2 have the same shape and size and are symmetrically arranged. The upper sheath 1 includes an upper ring portion 101 and an upper truncated cone portion 102. The upper truncated cone portion 102 is fixedly connected to the left end of the upper ring portion 101, and the upper ring portion 101 and the upper truncated cone portion 102 are integrally formed. The lower sheath 2 covers... The device includes a lower half-ring portion 201 and a lower half-truncated cone portion 202, with the lower half-truncated cone portion 202 fixedly connected to the left end of the lower half-ring portion 201. The lower half-ring portion 201 and the lower half-truncated cone portion 202 are integrally formed. Multiple sets of locking components 5 are sleeved on the upper half-shroud 1 and the lower half-shroud 2, used to lock and fix the connected upper half-shroud 1 and the lower half-shroud 2. One set of locking components 5 is used to lock and fix the connected upper half-truncated cone portion 102 and the lower half-truncated cone portion 202. The remaining locking components 5 are used to lock and fix the upper half ring 101 and the lower half ring 201 that are connected. The upper half sheath 1 and the lower half sheath 2 are respectively composed of an anti-slip buffer bonding layer 6, a fire-resistant and heat-insulating main body layer 7, a sealing fire-resistant and gas-proof layer 8, and a weather-resistant protective outer layer 9 from the inside to the outside. The inner surface of the anti-slip buffer bonding layer 6 is bonded to the outer surface of the original HDPE sheath of the bridge cable. The fire-resistant and heat-insulating main body layer 7 is fixedly connected to the outer surface of the anti-slip buffer bonding layer 6. The sealing fire-resistant and gas-proof layer 8 is fixedly connected to the outer surface of the fire-resistant and heat-insulating main body layer 7. The weather-resistant protective outer layer 9 is fixedly connected to the outer surface of the sealing fire-resistant and gas-proof layer 8. Several self-healing microcapsules 10 are implanted inside the fire-resistant and heat-insulating main body layer 7. The self-healing microcapsules 10 are used to automatically repair the micro-cracks on the fire-resistant and heat-insulating main body layer 7, as well as to automatically repair the peeling interface between the fire-resistant and heat-insulating main body layer 7 and the anti-slip buffer bonding layer 6 and the sealing fire-resistant and gas-proof layer 8.

[0042] In this embodiment, the anti-slip buffer bonding layer 6 can be made of modified high-damping fluororubber with a thickness of 1.2mm-1.5mm, internally doped with basalt short-cut fibers, possessing the functions of high-friction anti-slip, flexible buffering, and anti-scratch original sheath, which can prevent the overall slippage of the fire-resistant and heat-insulating sheath and adapt to the reciprocating bending deformation of bridge cables; the fire-resistant and heat-insulating main layer 7 can be made of hydrophobic modified high-silica fiber aerogel composite felt with a thickness of 6mm-10mm, a thermal conductivity ≤0.022W / (m·K), and can withstand flame temperatures up to 1100℃; the sealing fire-resistant and gas-barrier layer 8 can be made of basalt fiber cloth impregnated with ceramicized silicone rubber with a thickness of 1.8mm. With a thickness of 2.5mm, it exhibits high elasticity at room temperature, allowing it to deform with bridge cables. In the event of fire or high temperatures, it rapidly ceramicizes to form a dense fire-resistant shell, sealing pores and thermal bridges and preventing the penetration of flames and smoke. The weather-resistant outer layer 9 can be made of PVF fluorocarbon flame-retardant composite fabric, with a surface that is superhydrophobic, UV-resistant, and salt spray-resistant, providing an outdoor weather-resistant lifespan of ≥15 years. It should be noted that the outer wall of the weather-resistant outer layer 9 can be fitted with an integrally formed spiral vibration-damping protrusion structure (a conventional technique in this field, not shown in this article), which can counteract the aggravated wind vibration caused by the thickness of the fire-resistant and heat-insulating sheath, achieving synergy between fire protection and aerodynamic vibration suppression.

[0043] In this embodiment, the self-healing microcapsule 10 includes a spherical shell 1001 and a high-temperature resistant elastic sealing and repairing adhesive 1002. The high-temperature resistant elastic sealing and repairing adhesive 1002 fills the interior of the spherical shell 1001. The spherical shell 1001 can be made of a high-temperature resistant polyurethane-urea-formaldehyde composite brittle resin material with a particle size of 50μm-80μm and a wall thickness of 2μm-5μm. It has good weather resistance, UV resistance, and salt spray resistance. It is stable at room temperature, does not crack, and does not leak. It also has a set mechanical brittleness and will only break under the tensile or shear stress of microcracks, and will not spontaneously explode. The high-temperature resistant elastic sealing and repairing adhesive 1002 can be made of silicone-modified epoxy resin high-temperature flame-retardant repair liquid. After curing, it has a temperature resistance of ≥350℃ and a short-term fire resistance of 1100℃ without carbonization failure. It has high elasticity, high adhesion, and hydrophobic sealing properties. After curing, it can completely seal water seepage and air permeability gaps.

[0044] In this embodiment, it should be noted that the self-healing microcapsules 10 are implanted into the fire-resistant and heat-insulating main body layer 7 in the following manner: during the production stage of hydrophobic modified high silica fiber aerogel composite felt, self-healing microcapsules 10 with a uniform particle size of 50μm-80μm are uniformly mixed and impregnated into the pores of the composite felt, so that the self-healing microcapsules 10 are diffusely distributed throughout the thickness direction of the fire-resistant and heat-insulating main body layer 7 (distributed in the interior and the surface area near the interlayer interface).

[0045] In this embodiment, a semi-annular heat-insulating sealing strip 15 is fixedly connected to the outer right wall of both the upper half-ring portion 101 and the lower half-ring portion 201, and a semi-annular heat-insulating sealing strip 26 is fixedly connected to the inner wall of both the upper half-circular portion 102 and the lower half-circular portion 202. The inner diameter of the ring formed by the two semi-annular heat-insulating sealing strips 15 is the same as the inner diameter of the ring formed by the two semi-annular heat-insulating sealing strips 26. By utilizing the synergistic effect of the two semi-annular heat-insulating sealing strips 15 and 26, an annular seal can be formed at the joint of two adjacent fire-resistant heat-insulating sheaths, sealing the radial gap between the bridge cable and the upper half-circular portion 102 and the lower half-circular portion 202, and preventing external flames and rainwater from intruding from the joint, thereby achieving an effective sealing effect at the joint of two adjacent fire-resistant heat-insulating sheaths.

[0046] In this embodiment, each of the multiple locking components 5 includes an upper locking ring 501 and a lower locking ring 502. The upper locking ring 501 is fixedly connected to the outer surface of the upper sheath 1, and the lower locking ring 502 is fixedly connected to the outer surface of the lower sheath 2. Upper connecting blocks 503 are fixedly connected to both ends of the bottom of the upper locking ring 501, and lower connecting blocks 504 are fixedly connected to both ends of the top of the lower locking ring 502. The two lower connecting blocks 504 are detachably connected and fixed to their corresponding upper connecting blocks 503. The upper locking ring 501 and the lower locking ring 502... The synergistic effect allows them to form a complete clamp, providing circumferential locking pressure to tightly wrap and fix the upper half sheath 1 and the lower half sheath 2 to the outer surface of the bridge cable. A set of upper half locking rings 501 and lower half locking rings 502 located at the upper half truncated cone 102 and the lower half truncated cone 202 are used to clamp the areas of the upper half truncated cone 102 and the lower half truncated cone 202. The remaining sets of upper half locking rings 501 and lower half locking rings 502 are used to clamp the areas of the upper half ring 101 and the lower half ring 201, ensuring the overall fit and sealing of the fire-resistant and heat-insulating sheath with the bridge cable.

[0047] In this embodiment, the upper connecting block 503 and the upper locking ring 501 are integrally formed, and the lower connecting block 504 and the lower locking ring 502 are integrally formed, which can ensure the strength of the locking assembly 5 and its stability during use.

[0048] In this embodiment, the bottom of each of the two upper connecting blocks 503 is provided with a positioning groove 5031, and the top of each of the two lower connecting blocks 504 is fixedly connected with a positioning protrusion 505. The two positioning protrusions 505 are slidably installed in the corresponding positioning grooves 5031. By using the two positioning protrusions 505 to engage with the corresponding positioning grooves 5031, the upper half locking ring 501 and the lower half locking ring 502 can be pre-positioned during assembly, preventing the upper half locking ring 501 and the lower half locking ring 502 from shifting left and right, reducing assembly difficulty, and ensuring seam alignment.

[0049] In this embodiment, locking bolts 506 are threaded through both upper connecting blocks 503, and through holes 5041 are provided on both lower connecting blocks 504. The bottom ends of the two locking bolts 506 pass through the corresponding through holes 5041. Damping washers 507 are movably fitted on both locking bolts 506, and the two damping washers 507 abut against the bottom of the corresponding lower connecting block 504. Locking nuts 508 are threaded on both locking bolts 506, and the two locking nuts 508 respectively engage with the corresponding damping washers 507. The bottoms of the upper and lower locking rings 501 and 502 are abutted together by using locking bolts 506, damping washers 507 and locking nuts 508. The damping washers 507 can counteract the tendency of bolts to loosen due to long-term vibration of the bridge cable and maintain stable locking force. Moreover, by removing the locking nuts 508, it is convenient to release the locking of the upper and lower locking rings 501 and 502, that is, to release the clamping force on the upper sheath 1 and the lower sheath 2, so as to facilitate the disassembly and replacement of the upper and lower sheath 1 and the lower sheath 2.

[0050] In this embodiment, the bottom two sides of the upper half sheath 1 are provided with mating grooves 3, and the top two sides of the lower half sheath 2 are fixedly connected with sealing protrusions 4. The two sealing protrusions 4 are slidably installed in the corresponding mating grooves 3. By using the two sealing protrusions 4 to interlock with the corresponding mating grooves 3, the upper half sheath 1 and the lower half sheath 2 can be precisely spliced ​​and aligned to form a fire-resistant and heat-insulating sheath, which can provide all-round protection for the circumferential side of the bridge cable. This is achieved by using the lower half-circular part 202 and the upper half-circular part 102 to form a fire-resistant and heat-insulating sheath. The cone shape is formed by connecting the upper half ring 101 and the lower half ring 201 to form a cylindrical shape. With the clamping component 5, it can be used to tighten the end of the multi-section fire-resistant and heat-insulating sheath. The appropriate number of fire-resistant and heat-insulating sheaths can be selected according to the actual length of the bridge cable. The cable can be wrapped on site without cutting or disassembling it, making installation, maintenance and replacement simpler and more convenient, and reducing maintenance costs. The sealing convex strip 4 is made of the same modified high-damping fluororubber material as the anti-slip buffer bonding layer 6.

[0051] In this embodiment, both the semi-annular heat insulation sealing strip 15 and the semi-annular heat insulation sealing strip 16 can be integrally molded using high-temperature vulcanized ceramizable silicone rubber coated with basalt fiber foamed heat insulation core layer. The outer matrix is ​​ceramizable fire-resistant silicone rubber, and the interior is filled with hydrophobic modified basalt fiber foamed heat insulation felt. The overall flame retardant rating is UL94 V-0. It has high elasticity and rebound at room temperature, and can quickly form a dense ceramic heat insulation shell above 450°C. It can withstand a flame of 1100°C for a short time and has the properties of sealing and waterproofing, heat insulation and fire resistance, outdoor weather resistance and salt spray resistance, and vibration fatigue resistance. The upper locking ring 501 and the upper connecting block 503, as well as the lower locking ring 502, the lower connecting block 504, and the positioning protrusion 505 can all be integrally die-cast using 6061-T6 aluminum alloy. They have the advantages of being lightweight, high-strength, and having good vibration fatigue resistance. Furthermore, their outer surfaces are integrally coated with a ceramicized flame-retardant and anti-corrosion coating, which forms a heat insulation protective layer at high temperatures. It can withstand 1100℃ flame for short periods, and the locking structure does not soften or fail under fire conditions, continuously tightening the upper half of the protective sleeve 1 and the lower half of the protective sleeve 2; the locking bolt 506 and the locking nut 508 can both be made of 316L austenitic stainless steel, which has excellent salt spray resistance, UV resistance, and wide temperature range stability. The mechanical strength decreases little under high temperature conditions, and the threads are not prone to failure or corrosion under long-term vibration, making it easy to disassemble and maintain later; the damping washer 507 is made of 316L stainless steel thin skeleton with ceramicizable high temperature resistant fluororubber composite molding, which meets the requirements of damping anti-loosening, high temperature resistance, and corrosion resistance.

[0052] With the above structure, the fire-resistant and heat-insulating sheath for bridge cables provided in this application adopts a symmetrical split structure, consisting of a symmetrical upper sheath 1 and a lower sheath 2 that enclose the bridge cable. The two sealing protrusions 4 at the top of the lower sheath 2 are aligned and inserted into the two mating grooves 3 at the bottom of the upper sheath 1. The circumferential pre-alignment is achieved by the interlocking of the sealing protrusions 4 and the mating grooves 3. Then, multiple sets of locking components 5 are used to tighten the upper sheath 1 and lower sheath 2 in sections, and the positioning protrusions 505 at the top of the two lower connecting blocks 504 are respectively inserted into the corresponding upper connecting blocks. The upper half locking ring 501 and the lower half locking ring 502 are pre-positioned in the positioning groove 5031 at the bottom of block 503. Then, the locking bolt 506 and the damping washer 507 are inserted and tightened with the locking nut 508, thus completing the secure locking of the upper half locking ring 501 and the lower half locking ring 502, and completing the secure clamping of the upper half sheath 1 and the lower half sheath 2. The damping washer 507 can effectively offset the long-term wind vibration of the bridge cable, prevent the locking nut 508 from loosening, and continuously provide circumferential clamping force, so that the fire-resistant and heat-insulating sheath can reliably cover the outer surface of the bridge cable without slipping or falling off, thus achieving the protective effect.

[0053] Depending on the length of the bridge cable, multiple fire-resistant and heat-insulating sleeves can be installed on the outer surface of the bridge cable. When splicing two adjacent fire-resistant and heat-insulating sleeves, the upper half-ring 101 and lower half-ring 201 of one fire-resistant and heat-insulating sleeve are aligned and inserted into the aligned upper half-truncated cone 102 and lower half-truncated cone 202 of the other fire-resistant and heat-insulating sleeve. The two semi-annular heat-insulating sealing strips 15 are then pressed against the corresponding semi-annular heat-insulating sealing strips 16, and a set of locking components 5 on the outside of the upper half-truncated cone 102 and lower half-truncated cone 202 are securely locked, thus completing the reliable sealing of the two adjacent fire-resistant and heat-insulating sleeves. For sealing and docking, following the above operating steps, multiple fire-resistant and heat-insulating sleeves can be wrapped and docked sequentially. It should be noted that after the appropriate number of fire-resistant and heat-insulating sleeves are installed and docked on the entire bridge cable, the port of the first fire-resistant and heat-insulating sleeve (i.e., the port where the upper semi-circular part 102 and the lower semi-circular part 202 are spliced) can be sealed using a pre-made two-half spliced ​​complete circular baffle (of the same material as the semi-circular heat-insulating sealing strip 15), and 1-2 layers of PVF fluorocarbon flame-retardant composite cloth of the same material as the weather-resistant protective outer layer 9 are wrapped around the outside. The end is fixed with stainless steel cable ties.

[0054] During long-term use, when a section of the fire-resistant and heat-insulating sheath is partially damaged, maintenance personnel can remove the locking components on the damaged section of the fire-resistant and heat-insulating sheath and replace the damaged part separately without cutting or dismantling the bridge cable or dismantling the whole structure, which greatly reduces maintenance costs and on-site construction difficulty.

[0055] After the multi-section fire-resistant and heat-insulating sheath is installed on the bridge cable, the bridge cable can be protected against fire and heat. A non-slip buffer layer 6, made of modified high-damping fluororubber, is tightly bonded to the cable's original HDPE sheath. The modified high-damping fluororubber buffers the cable's reciprocating bending deformation caused by vehicles and wind loads, and increases the coefficient of friction, preventing the fire-resistant and heat-insulating sheath from slipping along the cable. Simultaneously, the soft material prevents the hard insulation layer from scratching the cable's outer sheath. The fire-resistant and heat-insulating main layer 7, made of hydrophobically modified high-silica fiber aerogel composite felt, has an extremely low thermal conductivity, forming a stable heat barrier. Under normal conditions, it isolates the cable from high temperatures caused by sunlight, and in the event of a fire, it blocks external flames. The heat from the flame is conducted to the internal steel cable of the cable, which can withstand a high temperature of 1100℃ for a short time, delaying the softening of the cable steel. By using a sealed fire-resistant and gas-barrier layer 8 made of basalt fiber cloth impregnated with ceramicized silicone rubber, the ceramicized silicone rubber is elastic at room temperature and can deform synchronously with the cable without cracking. When it encounters fire or high temperature, it will quickly undergo a ceramicization reaction to generate a hard and dense inorganic shell, sealing all the micropores, blocking the penetration of flames, high-temperature smoke and heat radiation into the interior, and eliminating interlayer thermal bridges. By using a weather-resistant protective outer layer 9 made of PVF fluorocarbon flame-retardant composite cloth, the outermost protective layer is formed, which can resist ultraviolet rays, salt spray and rainwater erosion, and extend the service life of the fire-resistant and heat-insulating sheath.

[0056] When the fire-resistant and heat-insulating sheath is installed on bridge cables, if the bridge cables experience continuous wind vibration, reciprocating bending, and interlayer shearing, causing micron-level microcracks in the fire-resistant and heat-insulating main layer 7, or if interface cracking or interlayer separation occurs between the fire-resistant and heat-insulating main layer 7 and the anti-slip buffer bonding layer 6, or between the fire-resistant and heat-insulating main layer 7 and the sealing fire-resistant and gas-barrier layer 8, stress concentration occurs at the tip of the microcrack. This stress acts on the spherical shell 1001 of the nearby self-healing microcapsule 10. Utilizing the brittle structure of the spherical shell 1001 itself, it can precisely rupture under minute deformation. After the spherical shell 1001 ruptures, the high-temperature resistant elastic sealing and repair adhesive 1002 inside will automatically flow capillarily, horizontally wetting the microcrack gaps or vertically penetrating the interlayer separation, thus automatically filling the defect area. After the sealing and repair adhesive 1002 solidifies, the micro-cracks will be filled and sealed by the high-temperature resistant elastic sealing and repair adhesive 1002. The gaps between the layers can then be re-bonded and laminated. After curing, the high-temperature resistant elastic sealing and repair adhesive 1002 forms a flexible high-temperature resistant sealing elastomer that can continue to follow the vibration and deformation of the bridge cable without secondary cracking. Furthermore, the high-temperature resistant elastic sealing and repair adhesive 1002 itself has flame-retardant and heat-insulating capabilities after curing, and no thermal bridges are generated at the repair site. This achieves in-situ automatic repair of micro-cracks and interlayer gaps inside the fire-resistant and heat-insulating sheath, solving the problems of delamination, cracks, thermal bridge leakage, and protection failure caused by bridge cable vibration. Moreover, the automatically repaired area is resistant to high temperatures, weathering, and vibration fatigue, significantly extending the service life of the fire-resistant and heat-insulating sheath and greatly improving the fire resistance, heat insulation, and safety of bridge cable protection.

[0057] Second Embodiment

[0058] Based on the fire-resistant and heat-insulating sheath for bridge cables provided in the first embodiment of this application, the second embodiment of this application proposes another fire-resistant and heat-insulating sheath for bridge cables. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.

[0059] The second embodiment of this application will be further described below with reference to the accompanying drawings and embodiments.

[0060] See Figure 8 , Figure 14 and Figure 15 In the fire-resistant and heat-insulating sheath used for bridge cables: a flexible fiber optic temperature sensor 11 is installed between the sealed fire-resistant and air-barrier layer 8 and the fire-resistant and heat-insulating main layer 7. The flexible fiber optic temperature sensor 11 is arranged in a serpentine pattern.

[0061] In this embodiment, a serpentine groove is formed on the surface of the sealed fire-resistant and gas-barrier layer 8 near the fire-resistant and heat-insulating main layer 7. The flexible fiber optic temperature sensor 11 is adhered and fixed in the serpentine groove by a high-temperature resistant flexible coupling adhesive. The flexible fiber optic temperature sensor 11 is in contact with the surface of the fire-resistant and heat-insulating main layer 7. Both ends of the flexible fiber optic temperature sensor 11 extend beyond the sealed fire-resistant and gas-barrier layer 8. A female connector 12 is fixedly connected to the left end of the sealed fire-resistant and gas-barrier layer 8, and a male connector 13 is fixedly connected to the right end of the sealed fire-resistant and gas-barrier layer 8. The male connector 13 is adapted to the female connector 12. By installing and fixing the flexible fiber optic temperature sensor 11 along the serpentine groove, the two flexible... Under the coordinated action of the flexible fiber optic temperature sensor 11, it can fully cover the length of the fire-resistant and heat-insulating sheath composed of the upper half sheath 1 and the lower half sheath 2, and can collect the temperature of the entire internal area of ​​the sheath in real time. It can realize accurate temperature monitoring in the early stage of fire and accurately locate the high temperature and ignition area. By designing male connector 13 and female connector 12, it is possible to adapt and plug them in end to end. When multiple fire-resistant and heat-insulating sheaths are axially spliced, the optical signal of the flexible fiber optic temperature sensor 11 can be connected in series. The structure and plugging method of male connector 13 and female connector 12 are mature technologies in this field, and those skilled in the art can know them without creative effort. Therefore, they will not be described in detail in this article.

[0062] In this embodiment, a semi-annular partition 14 is fixedly connected to the right end of both the upper half-ring 101 and the lower half-ring 201. The two ends of the two semi-annular partitions 14 abut against each other. The two semi-annular partitions 14 are integrally formed with the corresponding anti-slip buffer bonding layer 6. The male connector 13 is located on the outside of the semi-annular partition 14. The two semi-annular partitions 14 are joined together to form a cylindrical retaining ring. After the multiple fire-resistant and heat-insulating sheaths are axially spliced, the joined male connector 13 and female connector 12 can be isolated to prevent the male connector 13 and female connector 12 from contacting and rubbing against the surface of the bridge cable. The semi-annular partition 14 is made of the same modified high-damping fluororubber material as the anti-slip buffer bonding layer 6.

[0063] With the above structure, when the fire-resistant and heat-insulating sheath for bridge cables provided in this application is in use, the flexible fiber optic temperature sensor 11 is fixed in the serpentine groove with high-temperature resistant coupling adhesive and closely attached to the fire-resistant and heat-insulating main body layer 7, so that it can be arranged in a serpentine pattern along the entire length of the fire-resistant and heat-insulating sheath, with no temperature measurement blind spots, and can collect the temperature data of the entire internal area of ​​the fire-resistant and heat-insulating sheath in real time.

[0064] Since the flexible fiber optic temperature sensor 11 is connected to a female connector 12 and a male connector 13 at both ends, when multiple fire-resistant and heat-insulating sheaths are connected end to end, by first inserting the male connector 13 of two adjacent fire-resistant and heat-insulating sheaths into the female connector 12, the optical signals of the flexible fiber optic temperature sensor 11 can be connected in series, thus ensuring that the entire bridge cable protection section forms a continuous temperature measurement link. After the male connector 13 and the female connector 12 are inserted, the locking component 5 is used to tighten the connecting ends of the two adjacent fire-resistant and heat-insulating sheaths.

[0065] After the appropriate number of fire-resistant and heat-insulating sheaths are installed and connected on the entire bridge cable, the female connector 12 of the first fire-resistant and heat-insulating sheath and the male connector 13 of the last fire-resistant and heat-insulating sheath serve as the main line entrance and exit. From these two connectors, the signals are led outward and connected to the optical signal of the external temperature monitoring equipment. When high temperature or fire precursors appear in a local area of ​​the fire-resistant and heat-insulating sheath, the flexible fiber optic temperature sensor 11 can quickly detect the temperature anomaly, accurately locate the high-temperature section, and realize early fire warning. This allows the bridge administration department to take protective measures in advance to prevent the fire from spreading and damaging the bridge cable. It should be noted that the line connection, control, and early warning methods are conventional technical means that can be reasonably selected and implemented by those skilled in the art based on their ordinary technical knowledge without creative labor. Therefore, they will not be elaborated on in this article.

[0066] The fire-resistant and heat-insulating sheath for bridge cables provided in this application has been described in detail above. Specific embodiments have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A fire-resistant and heat-insulating sheath for bridge cables, characterized in that, It includes an upper sheath (1), a lower sheath (2) and multiple sets of locking components (5), wherein the upper sheath (1) and the lower sheath (2) are the same in shape and size and are arranged symmetrically; The upper sheath (1) includes an upper ring (101) and an upper frustum (102). The upper frustum (102) is fixedly connected to the left end of the upper ring (101). The upper ring (101) and the upper frustum (102) are integrally formed. The lower sheath (2) includes a lower ring (201) and a lower truncated cone (202). The lower truncated cone (202) is fixedly connected to the left end of the lower ring (201). The lower ring (201) and the lower truncated cone (202) are integrally formed. Multiple sets of locking components (5) are fitted onto the upper half sheath (1) and the lower half sheath (2) to lock and fix the connected upper half sheath (1) and the lower half sheath (2). One set of locking components (5) is used to lock and fix the connected upper half frustum (102) and the lower half frustum (202), while the other sets of locking components (5) are used to lock and fix the connected upper half ring (101) and the lower half ring (201). The upper sheath (1) and the lower sheath (2) each consist of, from the inside out, an anti-slip buffer bonding layer (6), a fire-resistant and heat-insulating main body layer (7), a sealing fire-resistant and gas-proof layer (8), and a weather-resistant protective outer layer (9). The fire-resistant and heat-insulating main body layer (7) is fixedly connected to the outer surface of the anti-slip buffer bonding layer (6), the sealing fire-resistant and gas-proof layer (8) is fixedly connected to the outer surface of the fire-resistant and heat-insulating main body layer (7), and the weather-resistant protective outer layer (9) is fixedly connected to the outer surface of the sealing fire-resistant and gas-proof layer (8). The main body layer (7) is implanted with several self-healing microcapsules (10) that are evenly distributed. The self-healing microcapsules (10) are used to automatically repair the micro-cracks on the fire-resistant and heat-insulating main body layer (7) and to automatically repair the peeling interface between the fire-resistant and heat-insulating main body layer (7) and the anti-slip buffer bonding layer (6) and the sealing fire-resistant and gas-proof layer (8). A flexible fiber optic temperature sensor (11) is provided between the sealing fire-resistant and gas-proof layer (8) and the fire-resistant and heat-insulating main body layer (7). The flexible fiber optic temperature sensor (11) is arranged in a serpentine pattern.

2. The fire-resistant and heat-insulating sheath for bridge cables according to claim 1, characterized in that: The self-healing microcapsule (10) includes a spherical shell (1001) and a high-temperature resistant elastic sealing and repairing adhesive (1002), wherein the high-temperature resistant elastic sealing and repairing adhesive (1002) is filled inside the spherical shell (1001).

3. The fire-resistant and heat-insulating sheath for bridge cables according to claim 1, characterized in that: The sealed fireproof and gas-proof layer (8) has a serpentine groove on one side of the fireproof and heat-insulating main body layer (7). The flexible fiber optic temperature sensor (11) is adhered and fixed in the serpentine groove by high-temperature resistant flexible coupling adhesive. The flexible fiber optic temperature sensor (11) is in contact with the surface of the fireproof and heat-insulating main body layer (7). Both ends of the flexible fiber optic temperature sensor (11) extend to the outside of the sealed fireproof and gas-proof layer (8). A female connector (12) is fixedly connected to the left end of the sealed fireproof and gas-proof layer (8), and a male connector (13) is fixedly connected to the right end of the sealed fireproof and gas-proof layer (8). The male connector (13) is compatible with the female connector (12).

4. The fire-resistant and heat-insulating sheath for bridge cables according to claim 3, characterized in that: The upper half ring (101) and the lower half ring (201) are both fixedly connected to the right end of a semi-annular partition (14). The two ends of the two semi-annular partitions (14) abut against each other. The two semi-annular partitions (14) are integrally formed with the corresponding anti-slip buffer bonding layer (6). The male connector (13) is located on the outside of the semi-annular partition (14).

5. The fire-resistant and heat-insulating sheath for bridge cables according to claim 1, characterized in that: A semi-annular heat-insulating sealing strip (15) is fixedly connected to the outer right side wall of the upper half ring (101) and the lower half ring (201), and a semi-annular heat-insulating sealing strip (26) is fixedly connected to the inner wall of the upper half frustum (102) and the lower half frustum (202). The inner diameter of the ring formed by the two semi-annular heat-insulating sealing strips (15) is the same as the inner diameter of the ring formed by the two semi-annular heat-insulating sealing strips (26).

6. The fire-resistant and heat-insulating sheath for bridge cables according to claim 1, characterized in that: Each of the multiple locking components (5) includes an upper locking ring (501) and a lower locking ring (502). The upper locking ring (501) is fixedly connected to the outer surface of the upper sheath (1), and the lower locking ring (502) is fixedly connected to the outer surface of the lower sheath (2). The bottom ends of the upper locking ring (501) are fixedly connected to upper connecting blocks (503), and the top ends of the lower locking ring (502) are fixedly connected to lower connecting blocks (504). The two lower connecting blocks (504) are detachably connected and fixed to the corresponding upper connecting blocks (503).

7. The fire-resistant and heat-insulating sheath for bridge cables according to claim 6, characterized in that: The upper connecting block (503) and the upper locking ring (501) are integrally formed, and the lower connecting block (504) and the lower locking ring (502) are integrally formed.

8. The fire-resistant and heat-insulating sheath for bridge cables according to claim 6, characterized in that: The bottom of each of the two upper connecting blocks (503) is provided with a positioning groove (5031), and the top of each of the two lower connecting blocks (504) is fixedly connected with a positioning protrusion (505). The two positioning protrusions (505) are respectively slidably installed in the corresponding positioning grooves (5031).

9. The fire-resistant and heat-insulating sheath for bridge cables according to claim 6, characterized in that: Both upper connecting blocks (503) are threaded with locking bolts (506), both lower connecting blocks (504) are provided with through holes (5041), the bottom ends of the two locking bolts (506) respectively pass through the corresponding through holes (5041), both locking bolts (506) are movably fitted with damping washers (507), the two damping washers (507) respectively abut against the bottom of the corresponding lower connecting block (504), both locking bolts (506) are threaded with locking nuts (508), the two locking nuts (508) respectively abut against the bottom of the corresponding damping washers (507).

10. The fire-resistant and heat-insulating sheath for bridge cables according to claim 1, characterized in that: The upper half sheath (1) has a docking groove (3) on both sides of its bottom, and the lower half sheath (2) has a sealing protrusion (4) fixedly connected to both sides of its top. The two sealing protrusions (4) are slidably installed in the corresponding docking grooves (3).

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