A permafrost slope radiation refrigeration protection component and construction method

Abstract

The application discloses a permafrost slope radiation refrigeration protection component and a construction method, and belongs to the technical field of permafrost subgrade thermal stability control, wherein the protection component is sequentially arranged from outside to inside by an exposed functional surface layer, a water-blocking layer and a supporting and anchoring layer. The exposed functional surface layer is a non-white mineral-based selective radiation refrigeration layer, and the outer surface is provided with snow-removing and flow-guiding textures; the water-blocking layer is sequentially provided with a dense water-blocking sublayer and a capillary resistance drainage sublayer, the capillary resistance drainage sublayer is provided with directional drainage channels extending along the slope and connected with the lower edge of the component; and the back of the supporting and anchoring layer is provided with back drainage ribs and anchoring holes. The upper and lower edges of the component are provided with matched and overlapped joints, and adjacent components are overlapped through the joints to form hidden splicing joints. The application integrates surface thermal regulation, liquid water blocking, capillary resistance drainage and slope stability into a single component, realizes multiple functions in the same protection unit, and reduces thermal-water coupling disturbance of the permafrost subgrade slope.

Description

Technical Field

[0001] This invention relates to the field of thermal stability control technology for permafrost roadbeds, and in particular to a radiation cooling protection component and construction method for permafrost slopes. Background Technology

[0002] In permafrost regions, during long-term service, the slopes and shoulders of highway subgrades are susceptible to the combined effects of solar radiation, temperature changes, rainfall, snowfall, and snowmelt, resulting in significant thermal-hydraulic coupled disturbances. Once continuous heat input and water infiltration occur on the slopes, it can easily lead to thickening of the active layer, decreased slope thermal stability, and local deformation, thereby affecting the overall service safety of the permafrost subgrade.

[0003] Existing measures for controlling the thermal stability of permafrost subgrades mainly include crushed stone slope protection, ventilated subgrades, sunshades, insulation boards, heat pipes, and their composite structures. While these measures can reduce heat input or improve airflow heat exchange under certain conditions, their application in localized areas of slopes may still present challenges such as large structural thickness, numerous construction steps, inconvenient maintenance and replacement, significant susceptibility to snow accumulation and wind erosion, and insufficient integration with surface waterproofing and drainage structures.

[0004] In recent years, surface reflective cooling materials, near-infrared reflective coatings, and other surface thermal control measures have been used to improve the solar radiation absorption of roadbed slopes. Conventional white reflective coatings or near-infrared reflective coatings can improve the surface's ability to reflect solar radiation, but they are mostly applied as standalone coatings, primarily focusing on reducing solar absorption. They typically do not simultaneously provide structural functions such as slope anchoring, joint waterproofing, capillary drainage, and back drainage. Under long-term service conditions in permafrost roadbed slopes, they still need to be used in conjunction with other protective or drainage structures. Furthermore, while directly using high-whiteness pure white reflective surfaces can improve solar reflectivity, it may create strong visual irritation in the open environment of roadside slopes. Moreover, the appearance and thermal control performance are easily degraded after contamination, resulting in insufficient visual harmony with the roadside slope environment.

[0005] Existing waterproofing and drainage measures, such as sprayed polyurea waterproofing layers, laying geomembranes, or geomembrane-gravel composite layers, can improve liquid water infiltration, water barrier, and drainage. However, their main functions are concentrated on waterproofing, water barrier, or drainage, and they typically do not consider the weighted reflectance of the solar spectrum on exposed surfaces, long-wave radiation heat dissipation through the 8–13 μm atmospheric window, or the adaptability to non-white environments with controlled brightness. For permafrost roadbed slopes, if only waterproofing and drainage structures are used without surface heat regulation functions, it may still be difficult to sufficiently reduce surface heat input caused by solar radiation.

[0006] Therefore, existing technologies still lack a protective structure suitable for permafrost roadbed slopes that can integrate a non-white radiative cooling exposed functional surface layer with controlled brightness, liquid water barrier, capillary drainage, back drainage, concealed joints and slope anchoring into one unit, while also taking into account surface thermal regulation, waterproof drainage, snow and surface attachment drainage, and the visual harmony of the road slope environment. Summary of the Invention

[0007] The purpose of this invention is to provide a radiation cooling protection component and construction method for permafrost slopes. By integrating the exposed functional surface layer, drainage layer and support anchoring layer into a single component, surface heat regulation, liquid water barrier, capillary drainage and slope stabilization are achieved in the same protection unit, thereby reducing the heat-water coupling disturbance of permafrost roadbed slopes.

[0008] To achieve the above objectives, this invention provides a radiation cooling protection component for permafrost slopes, comprising an exposed functional surface layer, a drainage layer, and a support and anchoring layer. The exposed functional surface layer, drainage layer, and support and anchoring layer are sequentially arranged from the outer side away from the permafrost slope base layer to the inner side near the permafrost slope base layer. The exposed functional surface layer is a non-white mineral-based selective radiation cooling layer exposed to the sky, and its outer surface is provided with a snow-drainage guiding texture formed by a combination of a micro-rough surface and macro-guiding channels. The drainage layer includes a dense water-blocking sublayer and capillary drainage. Sub-layers, including a dense water-blocking sub-layer and a capillary drainage sub-layer, are arranged sequentially from the exposed functional surface layer to the support and anchoring layer. The capillary drainage sub-layer has directional drainage channels that extend along the slope direction of the frozen soil slope and connect with the lower edge of the protective component. The support and anchoring layer has back drainage ribs and anchoring holes on its back side away from the capillary drainage sub-layer. The upper and lower edges of the protective component have interlocking tongues and grooves that cooperate with each other. Adjacent protective components are joined by the interlocking tongues and grooves to form a hidden splice joint located inside the interlocking tongues and grooves and grooves that do not directly penetrate the outer surface of the exposed functional surface layer.

[0009] Preferably, a slightly rough surface is provided on the outer surface of the exposed functional surface layer, and a number of macro-guiding channels are provided and arranged on the outer surface of the exposed functional surface layer. The macro-guiding channels are arranged along the slope direction of the frozen soil slope or at an inclination of 5° to 30° relative to the slope direction. The spacing between the macro-guiding channels is 5 to 30 mm, and the depth is 1 to 8 mm. The thickness of the exposed functional surface layer is 3–15 mm, the thickness of the drainage layer is 15–50 mm, and the thickness of the support and anchoring layer is 20–70 mm.

[0010] Preferably, the exposed functional surface layer has a non-white appearance with controlled brightness, a visible light intensity L* of 50 to 80, a solar reflectance of 0.90 to 0.96 calculated by solar spectrum weighting in the 0.28 to 2.5 μm band, and an average emissivity of 0.92 to 0.98 in the 8 to 13 μm atmospheric window.

[0011] Preferably, the exposed functional surface layer is made of hydraulic cementitious material, porous silica scattering component, high scattering inorganic filler and inorganic coloring pigment. The porous silica scattering component is diatomaceous earth, the high scattering inorganic filler is one or more of barium sulfate, alumina, calcium carbonate and titanium dioxide, and the inorganic coloring pigment is one or more of iron oxide, iron-chromium pigment, cobalt-aluminum spinel pigment and manganese pigment.

[0012] Preferably, the dense water-blocking sublayer is an inorganic cementitious layer, and the capillary retardant drainage sublayer is a lightweight porous inorganic layer with an average pore size larger than that of the dense water-blocking sublayer. The pores in the capillary retardant drainage sublayer are connected to the directional drainage channels.

[0013] Preferably, the support anchoring layer is a cement-based material layer, and the back drainage ribs are arranged along the slope direction of the frozen soil slope or at an angle to the slope direction, so as to form a back drainage gap between the support anchoring layer and the frozen soil slope base layer after the protective components are installed.

[0014] Preferably, the tongue and groove joint includes a covering end located at the upper edge of the protective member and a receiving end located at the lower edge of the protective member, wherein the covering end covers the joint area of ​​the concealed splice seam of the adjacent lower protective member.

[0015] Preferably, the tongue and groove joint has a sealing strip or is filled with sealing material. The sealing strip is a microporous elastic sealing strip, and the sealing material is a silane-modified sealant or a sealant containing mineral fillers.

[0016] This invention also provides a construction method for a radiation cooling protection component for permafrost slopes, comprising the following steps: S1, repair the base layer of the frozen soil slope and set up drainage ditches at the toe of the slope; S2, prepare the exposed functional surface layer slurry, and form snow removal and guiding textures on the surface of the exposed functional surface layer; S3, a dense water-blocking sub-layer, a capillary drainage sub-layer, and a support and anchoring layer are formed sequentially on the inner side of the exposed functional surface layer. A directional drainage channel extending along the slope direction of the frozen soil slope and communicating with the lower edge of the protective component is formed in the capillary drainage sub-layer. Back drainage ribs and anchoring holes are formed on the back of the support and anchoring layer. Interlocking tongues and grooves that cooperate with each other are formed on the upper and lower edges of the protective component. S4. Install protective components row by row from the bottom to the top of the slope, and fix the protective components to the base layer of the frozen soil slope by passing anchors through the anchor holes. S5, adjacent protective components are connected by overlapping tongue and groove joints in a staggered manner to form a hidden splice joint located inside the overlapping tongue and groove joint and not directly penetrating the outer surface of the protective component. S6 seals the concealed joints and connects the directional drainage channels, the back drainage gap formed by the back drainage ribs, and the slope toe drainage ditch.

[0017] Preferably, in S2, the micro-rough surface is made by one or more of the following methods: roughening, roughening, or sandblasting; and the macro-guided groove is made by one of the following methods: setting groove forming ribs in the mold, using an embossing mold, or rolling to form a groove. In S3, a directional drainage channel is formed by a core mold, a cavity forming strip, or a drainage strip; In S4, adjacent protective components are laid out in a staggered overlapping manner, and the anchors are anchor rods, anchor nails or mechanical connectors. Multiple protective components are deployed in zones on the sunny slope, shady slope, slope shoulder, or slope protection surface of the permafrost roadbed. The sunny slope area uses an exposed functional surface layer with a thickness greater than that of the shady slope area, and / or uses a snow drainage and guiding texture with a groove spacing smaller than that of the shady slope area.

[0018] The advantages and positive effects of the radiation cooling protection component and construction method for permafrost slopes described in this invention are as follows: 1. This invention uses a single-piece protective component as a carrier to integrate the exposed functional surface layer, the drainage layer and the support and anchoring layer, which can reduce the increase in interfaces and structural complexity caused by the on-site construction of multiple modules. 2. The exposed functional surface layer adopts a non-white mineral-based radiation cooling design with controlled brightness. While having a high solar spectral weighted reflectivity of 0.28 to 2.5 μm and an average emissivity of 8 to 13 μm atmospheric window, it avoids the use of a high-whiteness pure white appearance. This helps to reduce the risk of strong visual stimulation caused by high-whiteness pure white reflective surfaces in the roadside slope environment and improves the visual coordination between the protective components and the roadside slope environment. 3. By combining dense water-blocking sublayers, capillary drainage sublayers, and directional drainage channels, the infiltration and capillary rise of rainwater and snowmelt are reduced. 4. By combining overlapping tongue and groove joints, concealed splicing seams, back drainage ribs and snow drainage guide textures, snow accumulation, snow melt water, mud and dust are guided and drained along the surface of the protective components and the splicing area, reducing their retention on the surface and in the splicing. 5. Protective components can be prefabricated in the factory and assembled on site, and are suitable for zonal layout of permafrost roadbed slopes, shoulders and slope protection roads.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a schematic diagram showing the layout of the protective components of the present invention on the slope of a permafrost roadbed. Figure 2 This is an exploded view of the layered structure of the protective component of the present invention; Figure 3This is a schematic diagram of the tongue and groove joint between adjacent protective components and the concealed drainage path of the present invention; Figure 4 This is a schematic diagram of the heat-water synergistic working mechanism of the protective component of the present invention.

[0021] Figure label: 1. Road surface structure layer; 2. Embankment fill; 3. Slope top platform; 4. Slope base course; 5. Active layer; 6. Permafrost layer; 7. Protective components; 8. Anchors; 9. Drainage ditch; 10. Exposed functional surface layer; 11. Snow drainage and guiding texture; 12. Dense water-blocking sub-layer; 13. Capillary retardant drainage sub-layer; 14. Directional drainage channel; 15. Support and anchoring layer; 16. Back drainage rib; 17. Anchoring hole; 18. Overlap tongue and groove joint; 19. Concealed splice joint; 20. Sealing strip; 21. Back drainage gap. Detailed Implementation

[0022] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0024] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0025] Example 1: like Figure 1 , Figure 2 and Figure 3As shown, the permafrost subgrade and its underlying permafrost structure include a pavement structure layer 1, embankment fill 2, slope top platform 3, slope base course 4, active layer 5, and permafrost layer 6. The pavement structure layer 1 is located at the top of the subgrade, and the embankment fill 2 is located below the pavement structure layer 1, forming the main body of the subgrade. The slope top platform 3 is located between the outer edge of the pavement structure layer 1 and the subgrade slope, and the outer slope surface of the embankment fill 2 forms the slope base course 4. Below the slope base course 4, the soil layer near the ground surface affected by seasonal freeze-thaw cycles is the active layer 5, and below the active layer 5 is the permafrost layer 6. Protective components 7 are laid along the surface of the slope base course 4 and fixed to it by anchors 8. Drainage ditches 9 are provided at the toe of the slope to collect and drain water from the surface of the protective components 7, the directional drainage channel 14, and the back drainage gap 21.

[0026] The protective component 7 includes an exposed functional surface layer 10, a drainage layer, and a support and anchoring layer 15, which are sequentially arranged from the outer side away from the frozen soil slope base layer 4 to the inner side near the frozen soil slope base layer 4. The protective component 7 can be manufactured as a prefabricated plate, tile, block, or strip, preferably with a length of 400–1000 mm, a width of 300–800 mm, and a total thickness of 40–120 mm.

[0027] The exposed functional layer 10 is a non-white mineral-based selective radiation cooling layer exposed to the sky. The exposed functional layer 10 preferably has a thickness of 3–15 mm and is intended for direct exposure to the sky environment. This layer employs a mineral-based cementing system and incorporates porous silica scattering components and highly scattering inorganic fillers. The porous silica scattering component is diatomaceous earth, and the highly scattering inorganic filler is one or more of barium sulfate, alumina, calcium carbonate, and titanium dioxide. The inorganic coloring pigment is one or more of iron oxide, iron-chromium pigments, cobalt-aluminum spinel pigments, and manganese pigments. The exposed functional layer 10 comprises, by weight, 35–75 parts white silicate cement or low-alkali white cement, 5–35 parts diatomaceous earth, 5–45 parts barium sulfate, and 0.1–8 parts inorganic coloring pigment, with a water-cement ratio of 0.4–0.65. The preferred formulation, by weight, comprises: 60 parts white silicate cement, 20 parts diatomaceous earth, 20 parts barium sulfate, plus 0.5–3 parts inorganic coloring pigment, with a water-to-binder ratio of 0.5. Using this formulation, while maintaining a high solar spectral weighted reflectance of 0.28–2.5 μm and an average emissivity within the 8–13 μm atmospheric window, the surface exhibits a controlled non-white appearance, such as light gray, gray, or grayish-brown.

[0028] In this embodiment, "non-white" refers to the exposed functional surface layer 10 having a gray, light gray, grayish-brown, or other non-white appearance in the visible light range that differs from a high-whiteness pure white reflective surface, and its visible light intensity L* is preferably 50-80. Visible light intensity L* is used to define the brightness-controlled non-white appearance of the exposed functional surface layer 10. This non-white appearance helps improve the visual harmony between the protective component 7 and the roadside slope environment, and helps reduce the risk of strong visual stimulation from a high-whiteness pure white reflective surface in the roadside slope environment. The visible light intensity L* of the exposed functional surface layer 10 is 50-80, the solar reflectance calculated by solar spectrum weighting in the 0.28-2.5μm band is 0.90-0.96, and the average emissivity in the 8-13μm atmospheric window is 0.92-0.98. The above spectral parameters are used to reduce daytime solar radiation absorption and enhance long-wave radiation heat dissipation in the 8-13μm atmospheric window. The parameter range can be determined by the spectral test results of the exposed functional surface layer 10 sample.

[0029] The exposed functional surface layer 10 has a snow-draining and guiding texture 11 formed by a combination of a micro-roughened surface and macro-guiding grooves on its outer surface. The micro-roughened surface is located on the outer surface of the exposed functional surface layer 10, and several macro-guiding grooves are arranged on the outer surface of the exposed functional surface layer 10. The spacing between the macro-guiding grooves can be 5–30 mm, and the depth can be 1–8 mm, arranged along the slope or at an angle of 5°–30° relative to the slope. The snow-draining and guiding texture 11 is used to guide and drain snow, melted snow, mud, and dust from the surface of the component.

[0030] The drainage layer includes a dense water-blocking sublayer 12 and a capillary drainage-retaining sublayer 13, which are arranged sequentially along the direction from the exposed functional surface layer 10 to the support and anchoring layer 15. A directional drainage channel 14 is provided on the capillary drainage sublayer 13, extending along the slope direction of the frozen soil slope and communicating with the lower edge of the protective member 7.

[0031] The preferred thickness of the drainage layer is 15–50 mm. The dense water-blocking sub-layer 12 can be formed using a low-pore inorganic cementitious layer, while the capillary-retaining drainage sub-layer 13 can be formed using a lightweight porous inorganic layer with an average pore size larger than that of the dense water-blocking sub-layer 12. The pores in the capillary-retaining drainage sub-layer 13 are connected to the directional drainage channel 14, which is connected to the lower edge of the protective component 7, thereby guiding the small amount of water entering the component downwards for discharge.

[0032] The supporting anchoring layer 15 has back drainage ribs 16 and anchor holes 17 on its back side away from the capillary drainage sub-layer 13. The supporting anchoring layer 15 is preferably 20-70 mm thick and can be formed of cement-based material with or without fiber. The back side has back drainage ribs 16 and anchor holes 17. The back drainage ribs 16 are arranged along the slope direction of the frozen soil slope or at an angle to the slope direction, and are used to form a back drainage gap 21 between the back side of the protective member 7 and the frozen soil slope base layer 4. The anchor holes 17 are used to fix the structure with anchor rods, anchor nails or other mechanical connectors.

[0033] The upper and lower edges of the protective component 7 are provided with interlocking tongue-and-groove joints 18. After adjacent protective components 7 overlap through the tongue-and-groove joints 18, a hidden splice seam 19 is formed inside the tongue-and-groove joints 18 and does not directly penetrate the outer surface of the exposed functional surface layer 10. The upper and lower edges of the protective component 7 form the tongue-and-groove joints 18. After adjacent components are assembled, the upper component covers the splice area of ​​the lower component, forming a hidden splice seam 19 at the overlap. A sealing strip 20 or a sealing material can be installed inside the tongue-and-groove joint. The sealing strip 20 is a microporous elastic sealing strip 20, and the sealing material is a silane-modified sealant or a sealant containing mineral fillers.

[0034] Example 2: The construction method of the radiation cooling protection component 7 for permafrost slopes according to the present invention includes the following steps: S1, Slope base course 4 repair: Repair and level the permafrost roadbed slope, clean up loose soil and sharp protrusions, set up drainage ditch 9 at the toe of the slope, and set up a thin leveling layer or interface treatment layer as needed.

[0035] S2, component prefabrication: A rough forming surface for forming a micro-rough surface is set on the bottom surface of the mold, and a groove forming rib for forming macro-guided grooves is set; the prepared exposed functional surface layer 10 slurry is poured into the bottom of the mold and vibrated to make the slurry fully adhere to the rough forming surface and the groove forming ribs; after demolding, a micro-rough surface and several macro-guided grooves are formed on the outer surface of the exposed functional surface layer 10, which together constitute the snow removal and guiding texture 11.

[0036] S3, after it reaches a state suitable for composite molding, a dense water-blocking sub-layer 12 slurry is laid; then a capillary retardant drainage sub-layer 13 is formed, and a directional drainage channel 14 is formed in it through a core mold, cavity forming strip or drainage strip; finally, a support anchoring layer 15 is poured, and back drainage ribs 16, anchoring holes 17 and overlapping tongue and groove 18 are formed simultaneously. After curing, the prefabricated protective component 7 is demolded.

[0037] S4, Slope installation: Install protective components 7 row by row from the toe of the slope to the top of the slope, preferably using a staggered joint method; first fix the lower row of protective components 7, then install the upper row of protective components 7, and fix the protective components 7 to the slope base layer 4 through anchors 8.

[0038] S5, adjacent protective components 7 are connected by staggered joints through overlapping tongue and groove joints 18 to form a hidden splice joint 19 located inside the overlapping tongue and groove joint 18 and not directly penetrating the outer surface of the protective component 7.

[0039] S6, a sealing strip 20 or filling sealing material is installed in the joint 18 of the overlapping joint of the adjacent protective components 7 to retain a certain moisture release capacity at the joint, and to connect the directional drainage channel 14, the back drainage gap 21 formed by the back drainage rib 16 and the drainage ditch 9 at the foot of the slope.

[0040] Multiple protective components are deployed in seven zones on the surface of the sunny slope, shady slope, slope shoulder, or slope protection road of the permafrost subgrade. The sunny slope area uses an exposed functional surface layer 10 with a greater thickness than the shady slope area, and a snow-draining and guiding texture 11 with a smaller groove spacing. Alternatively, the sunny slope area can use a thicker exposed functional surface layer 10, a denser snow-draining and guiding texture 11, or a higher daytime radiative cooling capacity; the shady slope area can use a relatively lower configuration to improve the thermal asymmetry between the sunny and shady slopes of the subgrade.

[0041] Example 3: like Figure 4 As shown, under the influence of solar radiation during the warm season, the exposed functional surface layer 10 reduces the absorption of solar radiation through its high solar spectral weighted reflectivity of 0.28–2.5 μm. Simultaneously, its high average emissivity within the 8–13 μm atmospheric window range enhances long-wave radiation heat dissipation, thereby improving the heat input state of the protective component 7's surface. The exposed functional surface layer 10 has a non-white appearance with controlled brightness, distinguishing it from high-whiteness pure white reflective surfaces, which helps improve the visual harmony between the component and the roadside slope environment.

[0042] When there is rain, snow or snowmelt, the dense water-blocking sub-layer 12 preferentially blocks liquid water from rapidly penetrating into the deep part of the component; a small amount of water that enters the interior is difficult to form a continuous capillary rise in the capillary drainage sub-layer 13, and is discharged along the slope under the guidance of gravity and directional drainage channel 14.

[0043] The snow drainage texture 11 of the exposed functional surface layer 10 and the tongue-and-groove joints 18 of adjacent components work together to promote the drainage of snow crust, snowmelt, dust and mud along the surface of the components and the joint area, reducing their retention on the surface and in the joints. The support anchoring layer 15 is connected to the slope base layer 4 by anchors 8, and a back drainage gap 21 is formed by the back drainage ribs 16.

[0044] The exposed functional surface layer 10 has a solar reflectance of 0.90–0.96 in the 0.28–2.5 μm band, calculated by solar spectral weighting, and an average emissivity of 0.92–0.98 in the 8–13 μm atmospheric window. Through its higher solar spectral weighted reflectance, the exposed functional surface layer 10 can reduce daytime solar radiation absorption; through its higher average emissivity in the atmospheric window, it can enhance long-wave radiation heat dissipation, thereby improving the surface heat input state of permafrost roadbed slopes. These performance parameters can be obtained by adjusting the types and proportions of the cementitious materials, diatomaceous earth, high-scattering inorganic fillers, and inorganic coloring pigments, as well as the surface texture.

[0045] The protective component 7 described in this embodiment is suitable for permafrost roadbed slopes, shoulders, slope protection roads, and other non-main traffic surfaces, especially for permafrost road sections that are sensitive to thermal asymmetry between sunny and shady slopes, have significant rain and snow meltwater infiltration, and are significantly affected by pollution or snow accumulation; it is preferred not to be used as a direct wear layer in the main traffic wheel track area of ​​highways.

[0046] Therefore, by adopting the radiation cooling protection component 7 and construction method of the permafrost slope described in this invention, the exposed functional surface layer 10, the drainage layer and the support anchoring layer 15 are integrated into a single component, so that surface heat regulation, liquid water isolation, capillary drainage and slope stabilization are achieved in the same protection unit, thereby reducing the heat-water coupling disturbance of the permafrost roadbed slope.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A radiation cooling protection component for permafrost slopes, characterized in that: The structure comprises an exposed functional surface layer, a drainage layer, and a support and anchoring layer, arranged sequentially from the outer side away from the frozen soil slope base layer to the inner side near the frozen soil slope base layer. The exposed functional surface layer is a non-white mineral-based selective radiation cooling layer exposed to the sky, with its outer surface featuring snow-drainage guiding textures formed by a combination of micro-roughened surfaces and macro-level drainage channels. The drainage layer includes a dense water-blocking sublayer and a capillary drainage-retaining sublayer. The sub-layers are arranged sequentially from the exposed functional surface layer to the support and anchoring layer. The capillary drainage sub-layer is provided with directional drainage channels that extend along the slope direction of the frozen soil slope and connect with the lower edge of the protective component. The back of the support and anchoring layer away from the capillary drainage sub-layer is provided with back drainage ribs and anchoring holes. The upper and lower edges of the protective component are provided with interlocking tongue and groove joints. After adjacent protective components are joined by the interlocking tongue and groove joints, a hidden splicing joint is formed inside the interlocking tongue and groove joints that do not directly penetrate the outer surface of the exposed functional surface layer.

2. The radiation cooling protection component for permafrost slopes according to claim 1, characterized in that: A slightly rough surface is set on the outer surface of the exposed functional surface layer. Several macro-guiding channels are set and arranged on the outer surface of the exposed functional surface layer. The macro-guiding channels are arranged along the slope direction of the frozen soil slope or at an inclination of 5° to 30° relative to the slope direction. The spacing between the macro-guiding channels is 5 to 30 mm and the depth is 1 to 8 mm. The thickness of the exposed functional surface layer is 3–15 mm, the thickness of the drainage layer is 15–50 mm, and the thickness of the support and anchoring layer is 20–70 mm.

3. The radiation cooling protection component for permafrost slopes according to claim 1, characterized in that: The exposed functional surface layer has a non-white appearance with controlled brightness, a visible light intensity L* of 50–80, a solar reflectance of 0.90–0.96 calculated by solar spectrum in the 0.28–2.5 μm band, and an average emissivity of 0.92–0.98 in the 8–13 μm atmospheric window.

4. The radiation cooling protection component for permafrost slopes according to claim 1, characterized in that: The exposed functional surface layer is made of hydraulic cementitious material, porous silica scattering component, high scattering inorganic filler and inorganic coloring pigment. The porous silica scattering component is diatomaceous earth, the high scattering inorganic filler is one or more of barium sulfate, alumina, calcium carbonate and titanium dioxide, and the inorganic coloring pigment is one or more of iron oxide, iron-chromium pigment, cobalt-aluminum spinel pigment and manganese pigment.

5. The radiation cooling protection component for permafrost slopes according to claim 1, characterized in that: The dense water-blocking sublayer is an inorganic cementitious layer, while the capillary retardant drainage sublayer is a lightweight porous inorganic layer with an average pore size larger than that of the dense water-blocking sublayer. The pores in the capillary retardant drainage sublayer are connected to the directional drainage channels.

6. The radiation cooling protection component for permafrost slopes according to claim 1, characterized in that: The support anchoring layer is a cement-based material layer, and the back drainage ribs are arranged along the slope direction of the frozen soil slope or at an angle to the slope direction, so as to form a back drainage gap between the support anchoring layer and the base layer of the frozen soil slope after the protective components are installed.

7. The radiation cooling protection component for permafrost slopes according to claim 1, characterized in that: The tongue and groove joint includes a covering end located at the upper edge of the protective component and a receiving end located at the lower edge of the protective component. The covering end covers the joint area of ​​the concealed splice seam of the adjacent lower protective component.

8. The radiation cooling protection component for permafrost slopes according to claim 7, characterized in that: The tongue and groove joint has a sealing strip or is filled with sealing material. The sealing strip is a microporous elastic sealing strip, and the sealing material is silane-modified sealant or a sealant containing mineral filler.

9. A construction method for a radiation cooling protection component for permafrost slopes according to any one of claims 1-8, characterized in that: Includes the following steps: S1, repair the base layer of the frozen soil slope and set up drainage ditches at the toe of the slope; S2, prepare the exposed functional surface layer slurry, and form snow removal and guiding textures on the surface of the exposed functional surface layer; S3, a dense water-blocking sub-layer, a capillary drainage sub-layer, and a support and anchoring layer are formed sequentially on the inner side of the exposed functional surface layer. A directional drainage channel extending along the slope direction of the frozen soil slope and communicating with the lower edge of the protective component is formed in the capillary drainage sub-layer. Back drainage ribs and anchoring holes are formed on the back of the support and anchoring layer. Interlocking tongues and grooves that cooperate with each other are formed on the upper and lower edges of the protective component. S4. Install protective components row by row from the bottom to the top of the slope, and fix the protective components to the base layer of the frozen soil slope by passing anchors through the anchor holes. S5, adjacent protective components are connected by overlapping tongue and groove joints in a staggered manner to form a hidden splice joint located inside the overlapping tongue and groove joint and not directly penetrating the outer surface of the protective component. S6 seals the concealed joints and connects the directional drainage channels, the back drainage gap formed by the back drainage ribs, and the slope toe drainage ditch.

10. The construction method of the radiation cooling protection component for permafrost slopes according to claim 9, characterized in that: In S2, the micro-rough surface is made by one or more of the following methods: roughening, brushing, or sandblasting; the macro-guided groove is made by one of the following methods: setting groove forming ribs in the mold, using an embossing mold, or rolling to form a groove. In S3, a directional drainage channel is formed by a core mold, a cavity forming strip, or a drainage strip; In S4, adjacent protective components are laid out in a staggered overlapping manner, and the anchors are anchor rods, anchor nails or mechanical connectors. Multiple protective components are deployed in zones on the sunny slope, shady slope, slope shoulder, or slope protection surface of the permafrost roadbed. The sunny slope area uses an exposed functional surface layer with a thickness greater than that of the shady slope area, and / or uses a snow drainage and guiding texture with a groove spacing smaller than that of the shady slope area.

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