Combined support of a bio-based composite skeleton combined with high performance fillers and process for its preparation

Abstract

The application discloses a combined support combined with a bio-based composite material framework and high-performance filling materials and a preparation process thereof, and belongs to the technical field of bridge engineering materials. The support is composed of a porous net-shaped framework formed by a polylactic acid-based composite material, an interface bonding layer is formed on the inner surface of the framework pores through a bio-based polyurethane adhesive, and natural rubber, viscoelastic damping material or a shape memory alloy composite is poured as high-performance filling materials. The preparation process includes key steps such as framework mold pressing, interface treatment, vacuum pressure pouring and segmented vulcanization. Through the synergistic effect of the bio-based framework and the functional filling body, the bearing stability and environmental adaptability of the support are significantly improved, and the support has the advantages of strong maintainability and low life cycle cost, and is especially suitable for bridge engineering scenes in corrosive environments or high seismic requirements, and the balance between mechanical properties and ecological benefits is achieved.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering and relates to a combined support that combines a bio-based composite material skeleton with a high-performance filler material and its preparation process. Background Technology

[0002] In the field of bridge engineering, bearings, as key components connecting the superstructure and piers, directly affect the durability, seismic resistance, and environmental adaptability of bridges. Currently widely used metal bearings, rubber bearings, and concrete bearings all have significant technical limitations: metal bearings, although having strong load-bearing capacity, are susceptible to corrosion, resulting in high maintenance costs, with annual anti-corrosion costs accounting for 15%-20% of the total bridge maintenance cost, and their excessive weight exacerbates the bridge load; traditional rubber bearings rely on synthetic rubber materials, which are not only difficult to degrade and form "black pollution," but also lack weather resistance, and their service life is usually no more than 20 years under the dual effects of high-temperature softening and low-temperature brittleness, while their fixed elastic modulus makes them difficult to adapt to complex and variable load conditions; concrete bearings, due to their high brittleness and poor impact resistance, are prone to cracking under dynamic loads, and the on-site pouring and curing cycle is as long as 7-14 days, which cannot meet the requirements of modern bridge rapid construction and lightweighting.

[0003] While existing composite bearing technologies attempt to improve performance through material combinations, the interfacial bond strength between the skeleton and the filling layer is generally below 5 MPa, making them prone to delamination and detachment. Furthermore, the application of bio-based materials is mostly limited to surface coatings and has failed to form structural load-bearing components. These technical shortcomings lead to severe environmental compatibility and functional adaptability challenges for traditional bearings in special scenarios such as ecologically sensitive areas and cross-sea bridges. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a combined support that combines a bio-based composite material skeleton with a high-performance filler material and its preparation process, the core of which lies in the synergistic design of the bio-based composite material skeleton and the high-performance filler.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a combined support structure integrating a bio-based composite skeleton and a high-performance filler material, comprising a bio-based composite skeleton, a high-performance filler, and an interfacial bonding layer. The bio-based composite skeleton is a mesh-like porous structure made of glass fiber reinforced polylactic acid and nano-SiO2, with a quadrilateral or honeycomb shape. The high-performance filler, filling the pores of the skeleton, is selected from any one or a combination of the following: natural rubber with an elastic modulus of 2-10 MPa and a damping ratio of 0.03-0.08; viscoelastic damping material with a loss factor ≥0.3; or shape memory alloy particles filling rubber with an adaptive deformation capacity of ±5%. The interfacial bonding layer is a bio-based polyurethane adhesive applied between the skeleton and the filler. The filler is densely filled into the pores of the skeleton using a vacuum pressure infusion process, forming a chemical bond with the skeleton through the interfacial bonding layer.

[0006] Optionally, the bio-based composite material skeleton has a mesh-like porous structure with a pore size of 20-50 mm and a porosity of 30%-40%.

[0007] Optionally, the solid content of the interface adhesive layer is ≥90%, the coating amount is 200-300g / m², and the shear strength is ≥8MPa.

[0008] Optionally, the preparation method of the bio-based composite skeleton includes: blending glass fibers with a length of 2-5 mm with polylactic acid and nano-SiO2 in a twin-screw extruder at a blending temperature of 190-210℃ and a fiber volume fraction of 35%; molding at a mold temperature of 120-140℃ and a pressure of 15-20 MPa for a holding time of 5-8 min; and processing a dovetail groove structure after molding.

[0009] Optionally, the natural rubber formulation of the high-performance filler includes: 100 parts raw rubber, 30 parts carbon black, 2 parts sulfur, 1 part accelerator, and 5 parts softener.

[0010] Optionally, the composite process of the filler and the skeleton includes: using a vacuum pressure injection machine, the filler is injected into the pores of the skeleton under the conditions of vacuum degree <-0.08MPa and injection pressure of 2-3MPa; after injection, it is vulcanized by a flat vulcanizing machine at a vulcanization temperature of 150±5℃ and a pressure of 10-15MPa. The vulcanization time is adjusted according to the thickness of the support, and 40 minutes is required for every 10mm thickness.

[0011] Furthermore, a steel skeleton is connected to the outside of the bio-based composite material skeleton through an interfacial adhesive layer.

[0012] This invention also provides a manufacturing process for a composite support, comprising the following steps: skeleton preparation, which involves preparing a bio-based composite material skeleton using a compression molding process; filler casting, which involves filling the skeleton pores with a high-performance filler using a vacuum pressure injection process; vulcanization molding, which involves vulcanizing the filled composite structure; and performance testing, which involves testing the interfacial bonding strength and the overall mechanical properties of the support.

[0013] Optionally, in the vulcanization molding step, the vulcanization temperature is 150±5℃, the pressure is 10-15MPa, and the vulcanization time is adjusted according to the thickness of the support.

[0014] Optionally, during the filling process, the vacuum degree is <-0.08MPa and the injection pressure is 2-3MPa.

[0015] The beneficial effects of this invention are as follows: This composite support, combining a bio-based composite skeleton with high-performance filler materials, has achieved multiple technological breakthroughs in the field of bridge engineering through innovative structural design and material combination. Its core beneficial effects are mainly reflected in the following aspects: I. Overall performance improvement brought about by structural synergy Mechanical performance optimization: The composite structure of the mesh porous skeleton and the filling material forms a "rigid-flexible" mechanical system. The skeleton provides a stable load-bearing frame, effectively limiting the lateral deformation of the infill, and significantly increasing the compressive strength of the support; the filling material absorbs dynamic loads through elastic deformation, improving the damping performance of the overall structure. This synergistic effect enables the support to withstand both static pressure and dynamic impact.

[0016] Breakthrough in interface performance: The interface bonding layer constructed with bio-based polyurethane adhesive enables the skeleton and filler to form a chemical bond rather than a simple physical contact. This design solves the technical problem of easy delamination in traditional composite supports. The improved interface bonding strength enhances the overall structural integrity and improves long-term stability.

[0017] II. Advantages of Environmental Friendliness and Sustainability Green materials: Using a glass fiber reinforced polylactic acid and nano-SiO2 blend system as the scaffold substrate, the carbon footprint over the entire life cycle is significantly reduced compared to traditional metal or synthetic rubber materials. The application of bio-based materials also improves the environmental compatibility of the products after disposal.

[0018] Maintainable design: The modular structure allows for the individual replacement of damaged infill elements without the need for complete scrapping, reducing maintenance costs. This design is particularly suitable for bridge engineering in harsh environments requiring frequent maintenance.

[0019] III. Functional Adjustability and Engineering Adaptability Material combination flexibility: By selecting different types of filling materials (natural rubber, viscoelastic damping materials or shape memory alloy composite systems), the parameters such as the elastic modulus, damping characteristics and temperature adaptability of the bearing can be adjusted within a certain range to meet the needs of different scenarios such as highway bridges, railway bridges and bridges in earthquake zones.

[0020] Process compatibility: Vacuum pressure infusion ensures a dense distribution of filler material within complex pore structures, improving product performance consistency. The standardized molding-vulcanization process facilitates quality control and large-scale production.

[0021] IV. Economic Benefits and Engineering Value Life cycle cost advantage: Although the initial material cost may be slightly higher than that of traditional bearings, the overall life cycle cost is significantly reduced due to its strong corrosion resistance, extended maintenance cycle, and convenient replacement.

[0022] Improved construction efficiency: Prefabricated components reduce on-site installation time, making them particularly suitable for bridge renovation projects requiring rapid construction. The lightweight design also reduces transportation and hoisting difficulties.

[0023] This modular bearing, through an innovative combination of a bio-based framework and functionalized fillers, achieves a technological balance of green environmental protection, adjustable performance, and long-term durability while maintaining the basic functions of traditional bearings, providing a more sustainable solution for modern bridge engineering. Its technological value is particularly prominent in projects with high requirements for material environmental compatibility, such as bridges in ecologically sensitive areas and cross-sea bridges.

[0024] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of the present invention.

[0026] Figure reference numerals: 1 Bio-based composite skeleton, 2 High-performance filler, 3 Interfacial bonding layer, 4 Steel shell. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0029] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] Please see Figure 1 This invention discloses a combined support that combines a bio-based composite material skeleton with a high-performance filler material and its preparation process.

[0031] Core component preparation Preparation of the bio-based composite skeleton: Raw material ratio: 35% by volume of 2-5mm chopped glass fiber is blended with polylactic acid matrix, and 5wt% nano-SiO2 is added as a reinforcing phase. The mixture is fed into a twin-screw extruder and melt-blended and granulated in the temperature range of 190-210℃.

[0032] Molding process: The granules are placed in a steel mold preheated to 120-140℃ and molded under pressure of 15-20MPa for 5-8 minutes. After demolding, the granules are CNC machined to form a quadrilateral / honeycomb mesh structure with a pore diameter of 20-50mm and a porosity of 30-40%, and a dovetail groove mechanical interlocking structure is machined on the joint surface.

[0033] The interface bonding layer 3 uses a bio-based polyurethane adhesive (solid content ≥90%), which is applied using a high-pressure airless spraying device at a standard of 200-300 g / m² to form a uniform coating on all the inner pore walls of the bio-based composite skeleton 1. After coating, it is placed in a 40℃ oven for 30 minutes to achieve a shear strength ≥8 MPa.

[0034] Filler composite process High-performance filler 2 formulation offers three typical formulation options: Option A: Natural rubber system (100 parts raw rubber + 30 parts carbon black + 2 parts sulfur + 1 part accelerator + 5 parts softener) Option B: Viscoelastic damping material (butyl rubber matrix + 30% mica sheets + 15% plasticizer) Option C: Shape memory composite material (hydrogenated nitrile rubber + 20 vol% nickel-titanium alloy particles) Vacuum pressure infusion involves loading molten high-performance filler 2 into the infusion machine barrel and injecting it into the pores of the bio-based composite framework 1 at a pressure gradient of 2-3 MPa within a sealed chamber with a vacuum degree < -0.08 MPa. During the infusion process, the mold temperature is maintained at 80-100℃ to preserve material flowability.

[0035] The vulcanization and setting process employs a segmented vulcanization process: Primary vulcanization: Plate vulcanization at 150±5℃ / 10-15MPa, with time calculated as 40 minutes per 10mm thickness. Secondary curing: Curing in a 130℃ oven for 2 hours to eliminate internal stress.

[0036] Furthermore, a steel skeleton 4 is connected to the outside of the bio-based composite material skeleton 1 through an interface bonding layer 3.

[0037] Finished product processing and testing Post-processing Machining: Remove excess material and flash, and perform surface sandblasting (0.3mm alumina sand). Corrosion protection: Coating with a water-based polyurethane topcoat (dry film thickness ≥ 50 μm) Performance verification Interface testing: 90° peel test performed according to ASTM D3165 standard. Mechanical testing: Testing compressive modulus of elasticity (GB / T 1041) and damping ratio (ASTM E756). Durability testing: 1 million fatigue cycles at 0.1 Hz (load range 10-50 kN). Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. 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 be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A composite support combining a bio-based composite material skeleton and a high-performance filler material, characterized in that, include: Bio-based composite material skeleton: a mesh-like porous structure made of glass fiber reinforced polylactic acid and nano-SiO2, with a skeleton shape of quadrilateral or honeycomb. High-performance filler: A material selected from any one or a combination of the following to fill the pores of a skeleton: Natural rubber has an elastic modulus of 2-10 MPa and a damping ratio of 0.03-0.

08. Viscoelastic damping material with a loss factor ≥ 0.3; Shape memory alloy particles are filled with rubber, providing an adaptive deformation capability of ±5%. Interface bonding layer: a bio-based polyurethane adhesive applied between the skeleton and the filler; The high-performance filler is densely filled into the pores of the bio-based composite material skeleton through a vacuum pressure infusion process, and forms a chemical bond with the bio-based composite material skeleton through an interfacial bonding layer.

2. The combined support of bio-based composite material skeleton and high-performance filler material according to claim 1, characterized in that, The bio-based composite material skeleton has a mesh-like porous structure with a pore size of 20-50 mm and a porosity of 30%-40%.

3. The combined support of the bio-based composite material skeleton and high-performance filler material according to claim 1, characterized in that, The solid content of the interface adhesive layer is ≥90%, the coating amount is 200-300g / m², and the shear strength is ≥8MPa.

4. The combined support of the bio-based composite material skeleton and high-performance filler material according to claim 1, characterized in that, The preparation method of the bio-based composite material skeleton includes: Glass fibers with a length of 2-5 mm are blended with polylactic acid and nano-SiO2 in a twin-screw extruder at a blending temperature of 190-210℃, with a fiber volume fraction of 35%. The molding process is carried out under the conditions of mold temperature of 120-140℃ and pressure of 15-20MPa, with a holding time of 5-8min. After molding, a dovetail groove structure is processed.

5. The combined support of the bio-based composite material skeleton and high-performance filler material according to claim 1, characterized in that, The natural rubber formulation of the high-performance filler includes: 100 parts raw rubber, 30 parts carbon black, 2 parts sulfur, 1 part accelerator, and 5 parts softener.

6. The combined support of the bio-based composite material skeleton and high-performance filler material according to claim 1, characterized in that, The composite process of the high-performance filler and the bio-based composite material skeleton includes: A vacuum pressure infusion machine was used to infuse the filler into the pores of the bio-based composite material skeleton under conditions of vacuum degree <-0.08MPa and infusion pressure of 2-3MPa. After injection, it is vulcanized by a flat vulcanizing machine at a temperature of 150±5℃ and a pressure of 10-15MPa. The vulcanization time is adjusted according to the thickness of the support, requiring 40 minutes for every 10mm thickness.

7. The combined support of the bio-based composite material skeleton and high-performance filler material according to claim 1, characterized in that, A steel skeleton is connected to the outside of the bio-based composite material skeleton through an interfacial adhesive layer.

8. A manufacturing process for the combined support according to any one of claims 1-7, characterized in that, Includes the following steps: Skeleton preparation: Bio-based composite material skeletons were prepared using a compression molding process; Infiller casting: High-performance infillers are filled into the pores of the bio-based composite material skeleton using a vacuum pressure infusion process; Vulcanization molding: The process of vulcanizing the filled composite structure; Performance testing: Testing the interfacial bonding strength and the overall mechanical properties of the support.

9. The preparation process according to claim 8, characterized in that, In the vulcanization molding step, the vulcanization temperature is 150±5℃, the pressure is 10-15MPa, and the vulcanization time is adjusted according to the thickness of the support.

10. The preparation process according to claim 8, characterized in that, During the filling process, the vacuum degree is <-0.08MPa and the injection pressure is 2-3MPa.

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