Environment-friendly, renewable, light, high-strength and impact-resistant recombinant bamboo-foamed aluminum sandwich UHPC highway guardrail

Abstract

The invention discloses an environment-friendly, renewable, light, high-strength and impact-resistant recombinant bamboo-foamed aluminum sandwich UHPC (Ultra High Performance Concrete) composite guardrail, and belongs to the technical field of traffic guardrails. The composite guardrail comprises a guardrail main body, a fixed base and a connecting part, the guardrail body is of a layered composite structure and sequentially comprises an outer recombined bamboo board, a middle UHPC layer and a foamed aluminum sandwich layer from outside to inside, and all the layers are compounded into a whole through interface bonding layers. The guardrail main body is detachably connected with the fixed base through the connecting part. Through reasonable material compounding and structural design, the advantages of light weight and environment friendliness of the recombined bamboo, high strength and toughness of the UHPC and excellent energy absorption performance of the foamed aluminum are fully played, so that the composite guardrail has the characteristics of light weight, high strength, excellent impact resistance, good weather resistance, environment friendliness and reproducibility; meanwhile, the guardrail main body is detachably connected with the fixed base, so that the construction is convenient and fast, and the maintenance cost is low. The method is suitable for various traffic scenes such as urban roads, expressways and scenic spot roads, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of traffic guardrail technology, specifically to an environmentally friendly, renewable, lightweight, high-strength, and impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC highway guardrail. Background Technology

[0002] As a crucial component of transportation infrastructure, guardrails' core function is to absorb collision energy through deformation during vehicle collisions, effectively preventing vehicles from veering off the road and reducing injuries and property damage. Simultaneously, with the increasing popularity of green transportation and eco-friendly concepts, the environmental friendliness, renewability, and harmony with the natural environment of guardrails have become important research directions.

[0003] Currently, the most widely used guardrails on the market include traditional metal guardrails (such as steel guardrails and aluminum alloy guardrails), concrete guardrails, and some composite material guardrails. While traditional metal guardrails have good impact resistance, they suffer from problems such as heavy weight, susceptibility to corrosion, low recyclability, high energy consumption during production, and large carbon emissions, making them difficult to meet the demands of green and environmentally friendly development. Concrete guardrails, on the other hand, have drawbacks such as heavy weight, difficult construction, poor impact toughness, fragility after impact, and difficulty in repair; their production process also generates a significant carbon footprint.

[0004] To address these issues, researchers have begun exploring the combination of natural renewable materials and high-performance engineering materials to prepare composite railings. Reconstituted bamboo, as a novel green and environmentally friendly material, retains the advantages of bamboo—lightweight, high-strength, renewable, and with strong carbon sequestration capacity—while overcoming the defects of natural bamboo, such as anisotropy, susceptibility to decay, and poor dimensional stability. It has broad application prospects in the engineering field. Ultra-high performance concrete (UHPC) possesses ultra-high strength, ultra-high toughness, and excellent durability, significantly improving the load-bearing capacity and impact resistance of structures. Foamed aluminum, as a lightweight porous material, has good energy absorption performance, cushioning and shock absorption effects, and is corrosion-resistant and easy to process, making it an ideal impact-resistant sandwich material.

[0005] However, current technologies have not yet developed a reasonable composite design that combines reconstituted bamboo, aluminum foam, and UHPC to form a composite guardrail structure that combines excellent impact resistance, environmental friendliness, lightweight and high strength, and good dimensional stability. Some composite guardrails suffer from problems such as unreasonable material combinations, poor interfacial bonding, low impact energy absorption efficiency, and insufficient weather resistance, making it difficult to simultaneously meet the safety performance requirements and environmental protection needs of traffic guardrails. Therefore, developing a lightweight, high-strength, impact-resistant reconstituted bamboo-aluminum foam sandwich-UHPC composite guardrail with a scientifically designed structure, superior performance, and environmental recyclability has significant practical importance and application value. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing traffic guardrails, such as poor environmental performance, insufficient impact resistance, heavy weight, and poor weather resistance, and to provide an environmentally friendly, renewable, lightweight, high-strength, impact-resistant composite guardrail made of reconstituted bamboo-aluminum foam sandwich UHPC-reconstituted bamboo. This composite guardrail, through reasonable material composition and structural design, achieves lightweight, high strength, excellent impact energy absorption capacity, good weather resistance, and environmental renewability. It also features convenient construction and low maintenance costs, meeting the safety protection needs and ecological environmental protection requirements of different traffic scenarios.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] From the outside in, the structure consists of an outer layer of reconstituted bamboo, a middle UHPC layer, and a foamed aluminum core layer. These layers are bonded together by an interfacial adhesive layer. This innovative composite system fully leverages the synergistic advantages of reconstituted bamboo (environmentally friendly and renewable), UHPC (high strength and toughness), and foamed aluminum (excellent energy absorption). The main body of the railing is detachably connected to a fixed base via connecting components. The fixed base is used for fixed connection to the foundation. This detachable structure, combined with a modular design, ensures both ease of construction and future recyclability, enhancing its environmentally friendly characteristics throughout its entire lifecycle.

[0009] Furthermore, the outer layer of reconstituted bamboo board is made of modified reconstituted bamboo material with a thickness of 8mm~15mm. The preparation process of the modified reconstituted bamboo material is as follows: bamboo shavings are dried, then soaked in a modifier solution. After soaking, the bamboo is dried, then an adhesive is added and mixed evenly. The mixture is then hot-pressed and cured. The modifier solution is made by mixing boric acid, borax, silane coupling agent and water, wherein the mass fraction of boric acid is 1%~2%, the mass fraction of borax is 0.5%~1%, and the mass fraction of silane coupling agent is 0.3%~0.8%. The adhesive is a water-based polyurethane adhesive, and its addition amount is 8%~12% of the dry mass of the bamboo shavings.

[0010] Furthermore, the thickness of the intermediate UHPC layer is 20mm~30mm, and its mixing ratio (mass ratio) is: 600 parts~1200 parts of cement, 160 parts~240 parts of silica fume, 800 parts~1200 parts of quartz sand, 70 parts~150 parts of steel fiber, 8 parts~12 parts of high-efficiency water-reducing agent, and 120 parts~150 parts of water; the steel fiber is copper-plated microfiber steel fiber with a diameter of 0.1mm~0.2mm, a length of 8mm~12mm, and an aspect ratio of 40~80.

[0011] Furthermore, the thickness of the aluminum foam core layer is 20mm~50mm, its porosity is 60%~80%, and its compressive strength is 2MPa~5MPa. The surface of the aluminum foam core layer is provided with an uneven anti-slip texture with a texture depth of 2mm~5mm. This anti-slip texture is an innovative interface enhancement design, which can significantly increase the contact area between the aluminum foam and the intermediate UHPC layer. Combined with the interface bonding layer, it can achieve a tight bond between the layers, effectively avoiding interlayer delamination when the composite structure is under stress, and improving the overall structural integrity. At the same time, the porous structure of the aluminum foam can accurately match the impact energy absorption requirements. It can buffer the impact force through its own deformation and work together with the high-strength support of the UHPC layer to solve the technical contradiction of "impression resistance and lightweight imbalance" in traditional guardrails.

[0012] Furthermore, the interfacial bonding layer uses an epoxy-based adhesive with a thickness of 0.5mm to 1.5mm; the contact surfaces between the outer reconstituted bamboo board and the middle UHPC layer, and between the middle UHPC layer and the aluminum foam core layer, are all roughened, with a surface roughness Ra of 3.2μm to 6.3μm after roughening. This invention innovatively employs a multi-faceted interfacial reinforcement scheme of "texture design + roughening treatment + high-performance adhesive." Addressing the differences in interfacial compatibility between different materials (organic reconstituted bamboo and inorganic UHPC, inorganic UHPC and aluminum foam), it significantly improves interlayer bonding through the synergistic effect of physical reinforcement and chemical bonding, overcoming the technical bottleneck of weak interfacial bonding in traditional composite guardrails.

[0013] Furthermore, the connecting components include a pre-embedded steel plate, bolts, and nuts; the pre-embedded steel plate is embedded in the fixed base, and its surface is provided with threaded holes that match the bolts; the side of the guardrail body is provided with threaded holes that mate with the pre-embedded steel plate, and is fastened by nuts to achieve a detachable connection between the guardrail body and the fixed base.

[0014] Furthermore, the fixed base is made of reinforced concrete and has a steel reinforcement skeleton inside; the bottom of the fixed base is provided with anchor bolts, which are used to fix it to the foundation; the top of the connecting plate of the fixed base is provided with positioning bolt holes, and the top of the guardrail body is embedded in the positioning bolt holes and connected by anchor bolts on the top of the guardrail body.

[0015] Furthermore, the outer surface of the outer layer of reconstituted bamboo board is coated with a weather-resistant protective coating, which consists of a primer and a topcoat; the primer is a water-based epoxy primer with a thickness of 30μm~50μm; the topcoat is a fluorocarbon topcoat with a thickness of 50μm~80μm.

[0016] Furthermore, the composite guardrail also includes reflective marking components, which are fixedly disposed on the outer surface of the guardrail body and evenly distributed along the height direction of the guardrail body; the reflective marking components are reflective films or reflective strips with a width of 50mm~80mm and a thickness of 0.3mm~0.5mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) Innovative construction of a layered composite system of "reconstituted bamboo-UHPC-foamed aluminum" to achieve precise matching and synergistic effect of material advantages: The present invention breaks through the limitation of unreasonable material combination in the prior art. For the first time, it uses environmentally friendly and renewable modified reconstituted bamboo as the outer layer (to give full play to the advantages of lightweight, carbon sink and environmental protection), ultra-high strength and toughness UHPC as the middle layer (to ensure the foundation of load bearing and impact resistance), and high energy absorption foamed aluminum as the core layer (to buffer the impact force of collision). The synergistic effect of the three makes the composite guardrail have the core characteristics of environmental protection and renewable, lightweight, high strength and excellent impact resistance at the same time, which solves the technical problem of "poor environmental protection and insufficient impact resistance" of traditional guardrails. According to the test, the guardrail weighs only 32-45kg / m, which is much smaller than the traditional steel guardrail (about 60kg / m). When a 10t vehicle collides with it at 60km / h, it does not go out or break. The maximum deformation is ≤92mm, which is better than the national standard requirements. (2) Interface-enhanced structural innovation to improve overall structural stability and durability: Addressing the industry pain point of easy delamination between composite structure layers, this invention innovatively designs an anti-slip texture on the surface of the foam aluminum sandwich layer and roughens the contact surfaces of each material. Combined with a high-performance epoxy adhesive, it forms a multi-interface enhancement mechanism, effectively improving the interfacial bonding force between materials with different properties, avoiding interlayer separation under stress, and significantly enhancing the overall structural stability of the guardrail. At the same time, the outer layer of reconstituted bamboo board is modified with boric acid-borax-silane coupling agent and combined with a fluorocarbon weather-resistant protective coating, which greatly improves the weather resistance and corrosion resistance of the guardrail. After 1000 hours of accelerated artificial aging, the strength retention rate is ≥90%, and there is no rust after 1000 hours of salt spray testing, breaking through the limitations of insufficient durability of traditional composite guardrails. (3) The main body of the guardrail and the fixed base of the present invention adopt a detachable connection method, which is convenient for construction and easy for later maintenance, replacement and repair; the fixed base is reasonably designed and firmly connected to the foundation through anchor bolts, ensuring the installation stability of the guardrail; at the same time, the outer surface of the reconstituted bamboo board is coated with a weather-resistant protective coating, which further improves the weather resistance of the guardrail, extends its service life and reduces maintenance costs. (4) The present invention breaks through the defects of the existing composite guardrails that are "environmentally friendly but only in name" and builds a full life cycle environmental protection system from material selection to recycling: the core material reconstituted bamboo is a renewable resource, which absorbs CO2 during the growth process and has a carbon sink function. The modification and bonding process uses environmentally friendly auxiliary materials such as water-based polyurethane adhesive and water-based epoxy primer to reduce environmental pollution; foamed aluminum and UHPC materials have good recycling rate. The main body of the guardrail and the fixed base adopt a detachable modular design, which can be disassembled and recycled later, greatly reducing the generation of waste. The entire production and use process of the guardrail conforms to the concept of green environmental protection, and is especially suitable for scenic roads and other scenarios with high requirements for environmental coordination, expanding the application scope of composite guardrails. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the overall structure of the reconstituted bamboo-foam aluminum sandwich UHPC-reconstituted bamboo composite guardrail of the present invention;

[0019] Figure 2 This is a schematic diagram of the cross-sectional structure of the guardrail body of the present invention;

[0020] Figure 3 This is a schematic diagram of the connection structure between the connecting component and the fixed base of the present invention.

[0021] In the diagram: 1-main body of the guardrail, 11-outer layer of reconstituted bamboo board, 12-middle UHPC layer, 13-foam aluminum sandwich layer, 14-steel frame, 2-fixed base, 21-anchor bolt, 3-connecting component, 31-embedded steel plate, 32-bolt, 33-nut, 34-positioning bolt hole. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments.

[0023] Example 1: Combining Figures 1-3 Please provide an explanation.

[0024] An environmentally friendly, renewable, lightweight, high-strength, and impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail includes a guardrail body 1, a fixed base 2, and connecting components 3. The guardrail body 1 has a layered composite structure, consisting of an outer layer of reconstituted bamboo board 11, a middle UHPC layer 12, and a foam aluminum sandwich layer 13, from the outside to the inside. A steel mesh 14 is arranged inside the middle UHPC layer, and the outer layer of reconstituted bamboo board 11, the middle UHPC layer 12, and the foam aluminum sandwich layer 13 are bonded together by an interface bonding layer. The guardrail body 1 is detachably connected to the fixed base 2 via the connecting components 3, and the fixed base 2 is used for fixed connection to the foundation.

[0025] In this embodiment, the outer reconstituted bamboo board 11 is made of modified reconstituted bamboo material with a thickness of 10 mm. The preparation process of the modified reconstituted bamboo material is as follows: bamboo shavings are dried to a moisture content of 8-10%, then soaked in a modifier solution for 24 hours. After soaking, the bamboo is dried to a moisture content of 10%-12%, and then water-based polyurethane adhesive is added and mixed evenly. The mixture is then hot-pressed (hot-pressing temperature 120℃, hot-pressing pressure 3MPa, hot-pressing time 30min) and cured for 7 days. The modifier solution is prepared by mixing boric acid, borax, silane coupling agent and water, wherein the mass fraction of boric acid is 1.5%, the mass fraction of borax is 0.8%, and the mass fraction of silane coupling agent is 0.5%. The amount of water-based polyurethane adhesive added is 10% of the dry mass of the bamboo shavings.

[0026] The thickness of the intermediate UHPC layer 12 is 25mm, and its mixing ratio (mass ratio) is: 800 parts cement, 160 parts silica fume, 800 parts quartz sand, 120 parts copper-plated microfiber steel fiber, 10 parts high-efficiency water-reducing agent, and 150 parts water; the copper-plated microfiber steel fiber has a diameter of 0.15mm, a length of 10mm, and an aspect ratio of 67.

[0027] The aluminum foam core layer 13 has a thickness of 40 mm, a porosity of 70%, and a compressive strength of 3.5 MPa. The surface of the aluminum foam core layer 13 is provided with an uneven anti-slip texture with a texture depth of 3 mm.

[0028] The interface bonding layer uses an epoxy-based adhesive with a thickness of 1 mm; the contact surfaces between the outer reconstituted bamboo board 11 and the middle UHPC layer 12, and between the middle UHPC layer 12 and the foamed aluminum sandwich layer 13, are all roughened by sandblasting, and the surface roughness Ra after roughening is 4.8 μm.

[0029] The connecting component 3 includes a pre-embedded steel plate 31, a bolt 32, and a nut 33; the pre-embedded steel plate 31 is pre-embedded in the fixed base 2, and its surface is provided with threaded holes that match the bolt 32; the side of the guardrail body 1 is provided with mounting holes corresponding to the bolt 32, the bolt 32 passes through the mounting holes and engages with the threaded holes of the pre-embedded steel plate 31, and is fastened by the nut 33.

[0030] The fixed base 2 is made of reinforced concrete and has a steel reinforcement frame inside; the bottom of the fixed base 2 is provided with anchor bolts, which are used to fix it to the foundation; the top of the connecting plate of the fixed base 2 is provided with positioning bolt holes 34, and the top anchor bolts of the guardrail body 1 are fixed through the positioning bolt holes 34.

[0031] The outer surface of the outer layer reconstituted bamboo board 11 is coated with a weather-resistant protective coating, which consists of a water-based epoxy primer and a topcoat; the primer has a thickness of 40 μm; and the topcoat is a fluorocarbon topcoat with a thickness of 65 μm.

[0032] The composite guardrail also includes reflective marking components, which are fixedly installed on the outer surface of the guardrail body 1 and evenly distributed along the height direction of the guardrail body 1; the reflective marking components are reflective films with a width of 65mm and a thickness of 0.4mm.

[0033] The method for preparing the composite guardrail in this embodiment is as follows:

[0034] (1) Preparation of outer layer reconstituted bamboo board 11: The outer layer reconstituted bamboo board 11 is prepared according to the above-mentioned preparation process of modified reconstituted bamboo material, and the contact surface between it and the middle UHPC layer 12 is roughened by sandblasting, and then the weather-resistant protective coating 17 is coated on its outer surface.

[0035] (2) Preparation of intermediate UHPC layer 12: Weigh each raw material according to the above mixing ratio, mix cement, silica fume and quartz sand evenly, add high-efficiency water-reducing agent and water, stir to form mortar, then add steel fiber and stir evenly to obtain UHPC slurry;

[0036] (3) Preparation of aluminum foam sandwich layer 13: Select aluminum foam material that meets the requirements, process its surface to form anti-slip texture, and roughen its contact surface with the middle UHPC layer 12 by sandblasting.

[0037] (4) Composite molded guardrail body 1: In the mold, the outer layer of reconstituted bamboo board 11, the interface bonding layer 14, the middle UHPC layer 12, the interface bonding layer, and the foam aluminum sandwich layer 13 are laid in sequence. Then, pressure (pressure is 1MPa) is applied and cured. The curing temperature is 20-25℃ and the curing time is 14 days to obtain the guardrail body 1 that is composite. After curing, bolt holes are reserved on the side of the guardrail body 1.

[0038] (5) Install the fixed base 2: pour reinforced concrete fixed base 2 according to the design requirements, pre-embed steel plate 31 and anchor bolts, the top of the connecting plate of the fixed base 2 is provided with positioning bolt hole 34, and the top anchor bolt of the guardrail body 1 passes through the positioning bolt hole 34 for fixing;

[0039] (6) Assemble the composite guardrail: fix the top anchor bolt of the guardrail body 1 through the positioning bolt hole 34, and fasten the reserved bolt hole on the side of the guardrail 1 to the embedded steel plate 31 by bolt 32 and nut 33 to complete the assembly of the composite guardrail.

[0040] Example 2:

[0041] The difference between this embodiment and Embodiment 1 is that: the outer layer of reconstituted bamboo board 11 has a thickness of 8mm, the modifier solution contains 1% boric acid by mass, 0.5% borax by mass, 0.3% silane coupling agent by mass, and the amount of water-based polyurethane adhesive added is 8% of the dry weight of bamboo shavings; the middle UHPC layer 12 has a thickness of 20mm, and the mixing ratio (by mass) is: 800 parts cement, 240 parts silica fume, 1100 parts quartz sand, 120 parts steel fiber, 8 parts high-efficiency water-reducing agent, and 120 parts water; The aluminum foam core layer 13 has a thickness of 30 mm, a porosity of 60%, a compressive strength of 2 MPa, and an anti-slip texture depth of 2 mm; the interface bonding layer 14 has a thickness of 0.5 mm, and the surface roughness Ra after roughening treatment is 3.2 μm; the guardrail body 1 has a rectangular cross-section with a width of 100 mm and a height of 800 mm; the weather-resistant protective coating has a primer thickness of 30 μm and a topcoat thickness of 50 μm; the reflective marking component is a reflective strip with a width of 50 mm and a thickness of 0.3 mm. The remaining structure and manufacturing process are the same as in Example 1.

[0042] Example 3:

[0043] The difference between this embodiment and Embodiment 1 is that: the outer layer of reconstituted bamboo board 11 has a thickness of 15mm, the modifier solution contains 2% boric acid by mass, 1% borax by mass, 0.8% silane coupling agent by mass, and the amount of water-based polyurethane adhesive added is 12% of the dry weight of bamboo shavings; the middle UHPC layer 12 has a thickness of 30mm, and the mixing ratio (by mass) is: 800 parts cement, 160 parts silica fume, 1200 parts quartz sand, 150 parts steel fiber, 12 parts high-efficiency water-reducing agent, and 150 parts water; The aluminum foam sandwich layer 13 has a thickness of 50 mm, a porosity of 80%, a compressive strength of 5 MPa, and an anti-slip texture depth of 5 mm; the interface bonding layer has a thickness of 1.5 mm, and the surface roughness Ra after roughening treatment of the contact surface is 6.3 μm; the guardrail body 1 has an arc-shaped cross-section with a radius of curvature of 500 mm and a height of 1200 mm; the weather-resistant protective coating has a primer thickness of 50 μm and a topcoat thickness of 80 μm; the reflective marking component is a reflective film with a width of 80 mm and a thickness of 0.5 mm. The remaining structure and manufacturing process are the same as in Example 1.

[0044] The composite guardrails prepared in Examples 1-3 above were subjected to performance tests, and the test results are shown in the table below:

[0045]

[0046] The specific embodiments of the present invention have been described above, but the present invention is not limited to the above description. For those skilled in the art, any equivalent modifications and substitutions to the present technical solution are within the scope of the present invention. Therefore, all equivalent changes and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. An environmentally friendly, renewable, lightweight, high-strength, impact-resistant composite fence made of reconstituted bamboo, aluminum foam sandwich UHPC, and reconstituted bamboo, characterized in that... The system includes a guardrail body (1), a fixed base (2), and connecting components (3). The guardrail body (1) is a layered composite structure, consisting of an outer layer of reconstituted bamboo board (11), a middle UHPC layer (12), and a foam aluminum sandwich layer (13) from the outside to the inside. The outer layer of reconstituted bamboo board (11), the middle UHPC layer (12), and the foam aluminum sandwich layer (13) are bonded together by an interface bonding layer. The guardrail body (1) is detachably connected to the fixed base (2) through the connecting components (3). The fixed base (2) is used to fix the guardrail to the foundation.

2. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail according to claim 1, characterized in that, The outer layer of reconstituted bamboo board (11) is made of modified reconstituted bamboo material with a thickness of 8mm~15mm. The preparation process of the modified reconstituted bamboo material is as follows: bamboo is shaving and dried, then soaked in a modifier solution, dried after soaking, and then adhesive is added and mixed evenly. After hot pressing and curing, it is obtained. The modifier solution is made by mixing boric acid, borax, silane coupling agent and water, wherein the mass fraction of boric acid is 1-2%, the mass fraction of borax is 0.5%~1%, and the mass fraction of silane coupling agent is 0.3%~0.8%. The adhesive is a water-based polyurethane adhesive, and its addition amount is 8%~12% of the dry mass of bamboo shavings.

3. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail according to claim 1, characterized in that, The thickness of the intermediate UHPC layer (12) is 20-30mm, and its mix ratio (mass ratio) is: 600-1200 parts of cement, 160-240 parts of silica fume, 800-1200 parts of quartz sand, 70-150 parts of steel fiber, 8-12 parts of high-efficiency water-reducing agent, and 120-150 parts of water; the steel fiber is copper-plated microfiber steel fiber with a diameter of 0.1mm-0.2mm, a length of 8mm-12mm, and an aspect ratio of 40-80.

4. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail according to claim 1, characterized in that, The thickness of the aluminum foam core layer (13) is 30mm-50mm, its porosity is 60%~80%, and its compressive strength is 2MPa~5MPa; the surface of the aluminum foam core layer (13) is provided with uneven anti-slip texture, and the texture depth is 2-5mm.

5. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail according to claim 1, characterized in that, The interface bonding layer uses an epoxy adhesive with a thickness of 0.5mm to 1.5mm; the contact surfaces of the outer reconstituted bamboo board (11) and the middle UHPC layer (12), and the contact surfaces of the middle UHPC layer (12) and the foam aluminum sandwich layer (13) are all roughened, and the surface roughness Ra after roughening is 3.2μm to 6.3μm.

6. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail according to claim 1, characterized in that, The cross-section of the guardrail body (1) is trapezoidal, rectangular or arc-shaped; when it is trapezoidal, the width of the upper base is 80mm~120mm, the width of the lower base is 120mm~160mm and the height is 800mm~1200mm.

7. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail according to claim 1, characterized in that, The connecting component (3) includes a pre-embedded steel plate (31), a bolt (32), and a nut (33); the pre-embedded steel plate (31) is pre-embedded in the fixed base (2), and its surface is provided with a threaded hole that matches the bolt (32); the end side of the guardrail body (1) is provided with an installation hole corresponding to the bolt (32), the bolt (32) passes through the installation hole and engages with the threaded hole of the pre-embedded steel plate (31), and is fastened by the nut (33).

8. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail according to claim 1, characterized in that, The fixed base (2) is made of reinforced concrete and has a steel reinforcement skeleton inside; the bottom of the fixed base (2) is provided with anchor bolts, which are fixed to the foundation by the anchor bolts; the top of the connecting plate of the fixed base (2) is provided with positioning bolt holes 34, and the pre-embedded anchor bolts on the top of the guardrail body (1) are connected to the positioning bolt holes 34.

9. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite guardrail according to claim 1, characterized in that, The outer surface of the outer layer reconstituted bamboo board (11) is coated with a weather-resistant protective coating, which consists of a primer and a topcoat; the primer is a water-based epoxy primer with a thickness of 30-50μm; the topcoat is a fluorocarbon topcoat with a thickness of 50μm~80μm.

10. The environmentally friendly, renewable, lightweight, high-strength, impact-resistant reconstituted bamboo-foam aluminum sandwich UHPC composite fence according to any one of claims 1-9, characterized in that, It also includes reflective marking components, which are fixedly installed on the outer surface of the guardrail body (1) and evenly distributed along the height direction of the guardrail body (1); the reflective marking components are reflective films or reflective strips with a width of 50mm~80mm and a thickness of 0.3mm~0.5mm.

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