Design and construction method for recycling GFRP (Glass Fiber Reinforced Plastic) reinforced concrete beam of retired fan blade

Abstract

The invention relates to the technical field of composite material structural members, in particular to a design and construction method for recycling GFRP rib concrete beams of retired fan blades. A recycled GFRP (glass fiber reinforced plastic) reinforced concrete beam for retired fan blades comprises a concrete beam body, the bar framework is arranged in the concrete beam body and comprises at least two GFRP longitudinal stress bars arranged in the length direction of the concrete beam body and GFRP stirrups fixedly connected with the GFRP longitudinal stress bars and arranged in the length direction of the concrete beam body at intervals; wherein the GFRP longitudinal stress bars and the GFRP stirrups are all made of waste fan blade composite materials through mechanical recovery. The mechanically recycled GFRP rib material is used for replacing a traditional steel bar to serve as a stress bar of a concrete beam body, the environment pressure brought by large-scale composite material waste can be effectively relieved through recycling of the retired fan blade, conversion from a retired material of new energy equipment to a structural engineering material is achieved, and development of low-carbon circular economy is promoted.

Description

Technical Field

[0001] This application relates to the field of composite material structural components, and more specifically, to a design and construction method for a concrete beam reinforced with recycled GFRP (Glass Reinforced Polymer) from decommissioned wind turbine blades. Background Technology

[0002] As the global wind power industry continues to expand, a large number of early-operated wind turbine units are gradually entering their decommissioning phase. The pace of wind power equipment upgrades is accelerating, and the number of decommissioned wind turbine blades is increasing year by year. It is projected that in the coming decades, decommissioned wind turbine blades will constitute a continuously growing large-scale solid waste logistics stream. Wind turbine blades are mainly composed of glass fiber reinforced polymer (GFRP) and some carbon fiber reinforced composite materials. These materials are thermosetting resin-based composites, characterized by high strength, corrosion resistance, and low degradation. Currently, the recycling methods for decommissioned wind turbine blades mainly include three technical pathways: mechanical recycling, pyrolysis recycling, and chemical recycling, with mechanical recycling showing the best results.

[0003] The rapid development of the wind power industry has led to a large number of retired wind turbine blades that have reached the end of their service life. Their core material is glass fiber reinforced polymer (GFRP), which has high strength and corrosion resistance, but is difficult to degrade under natural conditions. Traditional landfill and incineration methods not only cause serious waste of resources, but also bring significant environmental disposal pressure, becoming a prominent pain point for the green development of the wind power industry.

[0004] Currently, the resource utilization of retired wind turbine blades is still in the low-value stage, mainly using them as fillers after crushing and preparing simple composite plates. A high-value utilization path for structural load-bearing components has not yet been formed, and the mechanical performance advantages of GFRP materials have not been fully utilized.

[0005] The steel bars commonly used in existing concrete structures are prone to corrosion and have a large self-weight. Summary of the Invention

[0006] The main objective of this application is to provide a design and construction method for a concrete beam with recycled GFRP reinforcement from decommissioned wind turbine blades, in order to solve the technical problems in the background art.

[0007] To achieve the above objectives, the first aspect of this application proposes a GFRP-reinforced concrete beam made from recycled GFRP reinforcement from decommissioned wind turbine blades, comprising: Concrete beams; The reinforcing skeleton, arranged within the concrete beam, includes at least two GFRP longitudinal reinforcing bars arranged along the length of the concrete beam, and GFRP stirrups fixedly connected to the GFRP longitudinal reinforcing bars and spaced apart along the length of the concrete beam; wherein, both the GFRP longitudinal reinforcing bars and the GFRP stirrups are made from waste wind turbine blade composite materials through mechanical recycling.

[0008] In some feasible embodiments, the outer surface of the GFRP longitudinal reinforcing rib is provided with an interface reinforcement structure, which is one or more of the following: spiral embossing, longitudinal groove, and surface roughening layer.

[0009] In some feasible embodiments, the GFRP longitudinal reinforcing bars are provided with sealing bodies at both ends to seal the openings at the bar ends and prevent slurry or particles from entering the interior of the bar ends.

[0010] In some possible implementations, the closure body is made of resin-based composite material, polymer material or metal material.

[0011] In some feasible methods, the matrix material of the GFRP longitudinal reinforcing bar and the GFRP stirrup is made of glass fiber, epoxy resin and composite filler from waste wind turbine blades, wherein the mass ratio of glass fiber in the matrix material is not less than 60%.

[0012] In some feasible embodiments, the concrete is concrete incorporating mechanically recycled glass fibers obtained from the mechanical processing and recycling of decommissioned wind turbine blades.

[0013] In some feasible methods, the GFRP stirrups and GFRP longitudinal reinforcing bars are fixedly connected by at least one of the following methods: binding, snap-fitting, sleeve-fitting, or resin consolidation, to form an integral reinforcing skeleton structure.

[0014] Secondly, this application provides a design method for a GFRP-reinforced concrete beam made from recycled GFRP reinforcement from decommissioned wind turbine blades, applicable to the aforementioned GFRP-reinforced concrete beam made from decommissioned wind turbine blades, comprising: Based on the stress requirements of the concrete beam, determine the concrete strength grade to incorporate fibers, and then incorporate short-cut fibers or mechanically recycled fiber reinforcement materials into the concrete based on the concrete strength grade. Based on the GFRP reinforcement prepared from recycled waste wind turbine blades, the mechanical properties of the GFRP reinforcement are determined, and the mechanical properties are used as the design basis for the tensile members of the concrete beam. The mechanical properties include its tensile strength, elastic modulus and ultimate strain. Based on the concrete strength grade and the mechanical properties of the GFRP reinforcement, the tensile bearing capacity of the tension zone of the concrete beam is designed, the required reinforcement cross-sectional area is calculated, and the reinforcement ratio of the GFRP reinforcement is not less than the set minimum reinforcement ratio, so as to obtain the cross-sectional area of ​​the longitudinal reinforcement of GFRP. Based on the shear force requirements of the concrete beam, the material type, diameter, and spacing of the stirrups are determined, and stirrups are set in the shear force control zone of the concrete beam to obtain the material type, location, diameter, and spacing of the GFRP stirrups.

[0015] Thirdly, this application provides a construction method for a concrete beam reinforced with recycled GFRP (Glass Reinforced Polymer) for decommissioned wind turbine blades, applicable to the aforementioned concrete beam reinforced with recycled GFRP for decommissioned wind turbine blades, comprising: The glass fiber material in the waste wind turbine blades is processed to obtain GFRP longitudinal reinforcing bars and GFRP stirrups, and an interface reinforcement structure is formed on the outer surface of the GFRP longitudinal reinforcing bars. A closing member body is installed at at least one end of the GFRP longitudinal reinforcing rib, so that the closing member body covers the opening of the GFRP longitudinal reinforcing rib and forms a closed structure; The GFRP longitudinal reinforcing bars are arranged according to the reinforcement requirements of the concrete beam section, and the GFRP stirrups are spaced apart along the length of the concrete beam to form a reinforcement skeleton by being fixedly connected with the GFRP longitudinal reinforcing bars. According to the design layout requirements, the GFRP longitudinal reinforcing bars and the GFRP stirrups are positioned, and the GFRP stirrups are fixed to the outside of the GFRP longitudinal reinforcing bars by at least one of the following methods: binding, snapping, sleeve connection or resin consolidation, to form a reinforcing skeleton. Then, the concrete beam formwork is installed, and the reinforcing skeleton is placed inside the concrete beam formwork so that the reinforcing skeleton is kept in a predetermined position inside the concrete beam formwork. Concrete is poured into the concrete beam formwork to cover the reinforcing skeleton and fill the gap between the concrete beam formwork and the reinforcing skeleton. The concrete beam is cured during the initial setting and hardening process. After the concrete beam reaches the predetermined strength, the concrete beam formwork is removed to form a concrete beam based on the GFRP reinforcement of discarded wind turbine blades.

[0016] Among the feasible methods, the curing of the concrete beam during or before the initial setting and hardening of the concrete beam includes: During or after the concrete pouring process, the concrete is vibrated to remove air bubbles and make it dense.

[0017] The technical solutions provided by the embodiments of this application may include the following beneficial effects: This application discloses a concrete beam reinforced with recycled GFRP (Glass Reinforced Plastic) for retired wind turbine blades. The longitudinal reinforcing bars and stirrups of GFRP, obtained through the mechanical recycling of waste wind turbine blade composite materials, serve as the core structural reinforcement of the concrete beam. This achieves high-value resource utilization of this difficult-to-degrade solid waste, breaking away from its low-value use as merely filler or simple composite panels. It fully leverages the mechanical properties of GFRP, effectively reducing resource waste and environmental pressure from landfilling and incineration of retired wind turbine blades, and alleviating the solid waste disposal pain points in the green development of the wind power industry. Simultaneously, replacing traditional steel bars with mechanically recycled GFRP reinforcement in the concrete beam avoids the defects of steel bars, such as easy corrosion and high weight. While achieving solid waste recycling, it also optimizes the material properties of the concrete beam, providing a better alternative for concrete structural reinforcement. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 This application provides a schematic diagram of the GFRP reinforcement skeleton structure of a concrete beam with recycled GFRP reinforcement from decommissioned wind turbine blades.

[0019] Figure 2 This application provides a schematic diagram of the end structure of the GFRP reinforcement skeleton of a concrete beam with recycled GFRP reinforcement from decommissioned wind turbine blades.

[0020] Figure 3 This application provides a schematic diagram of the enclosed body structure of a GFRP reinforced concrete beam for the purpose of reclaiming decommissioned wind turbine blades.

[0021] Figure 4 This application provides a schematic diagram of the longitudinal reinforcing bar interface reinforcement structure for a concrete beam with recycled GFRP reinforcement from decommissioned wind turbine blades.

[0022] Figure 5 This application provides a schematic diagram of the construction and assembly process for a GFRP reinforced concrete beam made from recycled decommissioned wind turbine blades.

[0023] Figure label: 1. Concrete beam; 2. GFRP longitudinal reinforcement; 3. GFRP stirrups; 4. Structural reinforcement; 5. Enclosure body. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0027] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0028] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linked," and "socketing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0029] like Figures 1 to 5As shown, in a first aspect, this application provides a GFRP-reinforced concrete beam made from recycled GFRP reinforcement from decommissioned wind turbine blades, comprising: Concrete beam 1; The reinforcement skeleton, arranged within the concrete beam 1, includes at least two GFRP longitudinal reinforcing bars 2 arranged along the length of the concrete beam 1, and GFRP stirrups 3 fixedly connected to the GFRP longitudinal reinforcing bars 2 and arranged at intervals along the length of the concrete beam 1.

[0030] The GFRP longitudinal reinforcing bars 2 and GFRP stirrups 3 are both made from waste wind turbine blade composite materials through mechanical recycling.

[0031] Furthermore, the outer surface of the GFRP longitudinal reinforcing rib 2 is provided with an interface reinforcement structure, which is one or more of the following: spiral embossing, longitudinal groove, and surface roughening layer.

[0032] In addition, the two ends of the GFRP longitudinal reinforcing rib 2 are provided with sealing body 5, which is used to seal the opening of the rib end and prevent slurry or particles from entering the interior of the rib end. The sealing body 5 is made of resin-based composite material, polymer material or metal material.

[0033] The matrix material of the GFRP longitudinal reinforcing bar 2 and the GFRP stirrup 3 is made of glass fiber, epoxy resin and composite filler from waste wind turbine blades, wherein the mass ratio of glass fiber in the matrix material is not less than 60%.

[0034] Specifically, the reinforcing skeleton is pre-embedded and fixed inside the concrete beam 1, providing core mechanical support for the concrete beam 1 in terms of tensile and shear resistance. The whole structure is composed of GFRP longitudinal reinforcing bars and GFRP stirrups, and GFRP structural reinforcing bars 4 can also be set in conjunction. The matrix materials of the GFRP longitudinal reinforcing bars, GFRP stirrups, and GFRP structural reinforcing bars 4 are all made from recycled glass fiber, epoxy resin, and composite filler from waste wind turbine blades through secondary processing. Among them, the mechanically recycled glass fiber from waste wind turbine blades accounts for no less than 60% of the mass of the matrix material. The composite filler is an inorganic filler recycled from waste wind turbine blades. Specifically, the length, direction distribution, and epoxy resin content of the mechanically recycled glass fiber can be adjusted according to the load-bearing requirements of the concrete beam 1 to achieve controllable regeneration of the mechanical properties of the reinforcing material.

[0035] GFRP reinforcement can be manufactured using a molding system with glass fiber as the reinforcement and epoxy resin as the matrix. For longitudinal GFRP reinforcement, a high fiber content system is preferred. Specifically, the preferred high fiber content system is 75% glass fiber by volume, 25% epoxy resin by volume, and no composite filler added. For GFRP stirrups, considering their bending and shear restraint requirements, the preferred system is 72% glass fiber by volume, 25% epoxy resin by volume, and 3% composite filler by volume.

[0036] The GFRP longitudinal reinforcing ribs are mainly composed of cut recycled GFRP strips, with continuous glass fiber bundles arranged along the rib axis. They are obtained through epoxy resin impregnation, preforming, and secondary hot pressing. The length of the recycled GFRP strips is preferably 40 mm. The preformed blank after impregnation is subjected to a pressure of 10 MPa at 100 °C for 25 min, followed by curing at 130 °C for 2 h. After demolding, a solid circular or quasi-circular GFRP longitudinal reinforcing rib is formed. The tensile strength of the GFRP longitudinal reinforcing ribs is not less than 500 MPa, preferably not less than 600 MPa, and the elastic modulus is not less than 35 GPa.

[0037] The GFRP stirrups are preferably prepared using a closed-loop winding molding process, in which continuous glass fiber bundles after resin impregnation and recycled GFRP strips are wound together on the surface of a closed mold core, cured at 100 ℃ for 60 min, then cured at 125 ℃ for 2 h, and then demolded. Alternatively, a closed-mold hot-press integral molding process can be used, applying a pressure of 8 MPa at 100 ℃ and holding for 30 min to obtain closed GFRP stirrups. The strength ratio of the bent section to the straight section of the stirrup is not less than 0.65, preferably not less than 0.75.

[0038] GFRP longitudinal reinforcement: arranged along the length of the concrete beam 1, with no less than two bars, arranged in parallel at the core position of the tension zone of the beam, and is the main component bearing the bending tensile stress of the beam; its cross-section is a solid near-circular shape, including circular, near-circular, elliptical and other near-circular cross-sections without sharp edges, the reinforcement body has no through hollow channel, and the diameter is selected according to the beam bearing capacity design requirements.

[0039] GFRP stirrups: Arranged at intervals along the length of the concrete beam, they surround the outer side of the longitudinal reinforcing bars of GFRP and are fixedly connected to the longitudinal reinforcing bars to form circumferential constraints. They are the core components that bear the shear force of the beam. The spacing of the stirrups is designed according to the shear force distribution characteristics of the beam. The spacing can be appropriately reduced in the shear force concentration area. The connection nodes of the GFRP stirrups and the longitudinal reinforcing bars of GFRP form a stable spatial constraint structure to prevent the longitudinal reinforcing bars from lateral instability or displacement.

[0040] It may also include GFRP structural reinforcement 4: arranged along the vertical height direction of the longitudinal section of the concrete beam 1, with no less than two bars, fixedly connected to the GFRP longitudinal reinforcing bars and GFRP stirrups, used to assist in positioning the GFRP longitudinal reinforcing bars 2 and enhance the overall stability of the reinforcement skeleton.

[0041] The outer surface of the GFRP longitudinal reinforcing bar is integrally formed or post-processed with an interface reinforcement structure. This structure is one or more combinations of spiral embossing, longitudinal grooves, and surface roughening layer. Its core function is to increase the contact area between the reinforcing bar and the concrete, improve the interfacial bonding performance between the reinforcing bar and the concrete through mechanical interlocking and micro-friction, prevent relative slippage between the two during the stress process, and ensure that the reinforcing bar and the concrete share the stress together.

[0042] Spiral embossing: The embossing is distributed in a continuous or intermittent spiral along the longitudinal reinforcing bar of GFRP. The height of the embossing is 0.5% to 3% of the diameter of the reinforcing bar, preferably 1.5%, and the pitch is 0.5 to 2 times the diameter of the reinforcing bar, preferably 1 time. After the concrete is poured, it will fill the gaps of the embossing, forming a mechanical interlocking structure along the circumference of the reinforcing bar, which restricts the circumferential and axial slippage between the reinforcing bar and the concrete.

[0043] Longitudinal grooves: Grooves are formed parallel to the longitudinal reinforcing bars of GFRP. The grooves are evenly distributed in a ring around the circumference of the reinforcing bar. The groove depth does not exceed 5% of the diameter of the reinforcing bar, and the groove width is 1 to 2 times the groove depth, preferably 1.5 times. The number of grooves on a single reinforcing bar is not less than 4. After the concrete is embedded in the groove, it forms an axial mechanical interlock, which enhances the axial bonding force between the reinforcing bar and the concrete.

[0044] Surface roughening layer: A microscopic uneven structure formed on the outer surface of the GFRP longitudinal reinforcing bar through surface treatment processes such as sandblasting, grinding, and sand planting. It has no fixed geometric shape, and the surface roughness Ra can be adjusted as needed, for example, not less than 25μm. The sand planting layer is a sand particle layer, which uses recycled glass sand obtained from the crushing of waste wind turbine blades. The sand particle size is 0.1mm to 0.5mm, preferably 0.3mm. It is bonded to the surface of the GFRP longitudinal reinforcing bar with epoxy resin adhesive of the same origin as the GFRP longitudinal reinforcing bar matrix. The core of this structure is to increase the microscopic friction coefficient of the GFRP longitudinal reinforcing bar surface, improve the interfacial static friction between the GFRP longitudinal reinforcing bar and the concrete, and enhance the interfacial bonding effect.

[0045] At least one end of the GFRP longitudinal reinforcing bar is provided with an end sealing component, preferably both ends of the GFRP longitudinal reinforcing bar at both ends of the beam. The sealing component body 5 is used to seal the micro-openings, fiber pores and interlayer gaps at the end of the reinforcing bar, preventing the slurry and sand particles from penetrating into the interior of the reinforcing bar during concrete pouring and vibration, avoiding performance degradation of the internal fibers of the reinforcing bar due to slurry erosion, and preventing splitting failure at the end of the reinforcing bar due to stress concentration, thus ensuring the stability of the mechanical properties of the end of the GFRP longitudinal reinforcing bar 2.

[0046] Furthermore, the material of the closure body 5 is made of resin-based composite material, polymer material or metal material. The mechanical properties of the material are matched with the longitudinal stress ribs of GFRP to avoid stress concentration at the ends due to excessive differences in material stiffness. The structure of the sealing component body 5: The shape is a fitting structure that precisely matches the end section of the longitudinal reinforcing bar of GFRP. It is a solid sealing structure. Its coverage area completely covers the open section of the end of the reinforcing bar and the outer circumferential edge of the end. The sealing depth is designed according to the diameter of the reinforcing bar to ensure the sealing effect. Fixing method: The enclosure body 5 is fixedly connected to the end of the GFRP longitudinal reinforcing bar by bonding, nesting or pressing. The connection surface fits seamlessly. When bonding, epoxy resin adhesive compatible with the reinforcing bar matrix is ​​used. When nesting or pressing, an interference fit design is adopted to ensure that the enclosure body 5 is firmly connected to the end of the reinforcing bar and will not fall off or loosen during construction and service.

[0047] It should be noted that the main cross-section of the GFRP longitudinal reinforcing bar is a solid near-circular shape. It is made from glass fiber, epoxy resin and composite filler from waste wind turbine blades through cutting, recombining and secondary pressing. The reinforcing bar body has no through hollow channels, which can fully guarantee the axial tensile mechanical properties of the reinforcing bar. However, due to the limitations of the recycling process, after the ends of the GFRP longitudinal reinforcing bar are cut, there will inevitably be interlayer pores of glass fiber, micro gaps formed by resin curing and micro-opening structures formed by exposed fibers. It is not a complete and dense solid end face.

[0048] Although these micro-openings at the ends do not have obvious through hollow channels, they can cause concrete slurry and fine sand and gravel particles to seep into the interior of the longitudinal reinforcing bars of GFRP during concrete pouring and vibration. This can damage the bonding interface between the end fibers and the resin matrix, leading to stress concentration and deterioration of mechanical properties at the ends of the reinforcing bars, and ultimately affecting the synergistic stress-bearing effect between the reinforcing bars and concrete. Therefore, it is necessary to install a sealing component body 5 for sealing treatment.

[0049] The core function of the enclosure body 5 is: It prevents concrete slurry and fine particles from entering the micropores at the ends of the longitudinal reinforcing bars of GFRP, prevents the fiber from debonding at the interface with the resin matrix, and ensures the integrity of the mechanical properties at the ends of the longitudinal reinforcing bars of GFRP. Wrap and fix the exposed glass fibers at the ends of the longitudinal reinforcing bars of GFRP to prevent the fibers from falling off or being damaged during construction, and at the same time eliminate the stress concentration problem caused by the sharp edges of the end fibers; The formation of a dense end stress surface ensures uniform transmission of tensile stress in the longitudinal reinforcement of GFRP, preventing splitting failure at the ends due to pore defects and enhancing the overall cooperative stress-bearing capacity of the longitudinal reinforcement of GFRP and the concrete beam 1.

[0050] It should also be noted that the GFRP stirrups 3 and the GFRP longitudinal reinforcing bars 2 are fixedly connected by at least one of the following methods: binding, snap-fitting, sleeve connection, or resin consolidation, to form an integral reinforcing skeleton structure. This fixed connection system is designed for the non-weldable material characteristics of GFRP reinforcing bars in decommissioned wind turbine blades. It avoids irreversible thermal damage to the internal fiber structure and resin matrix of GFRP reinforcing bars caused by traditional steel bar welding processes, ensuring the integrity of the mechanical properties of mechanically recycled reinforcing bars. At the same time, through stable node constraints, the GFRP stirrups and GFRP longitudinal reinforcing bars form a spatially integrated rigid reinforcing skeleton, ensuring that the reinforcing skeleton does not experience node loosening, reinforcing bar displacement, or skeleton deformation during installation, concrete pouring, and vibration, accurately maintaining the designed reinforcement position, and ultimately ensuring the stable performance of the beam's bending and shear bearing capacity. The specific implementation details of each fixed connection method are as follows: For binding and fixing, use non-magnetic non-metallic binding tape that matches the corrosion resistance of GFRP reinforcement (preferably binding tape made of glass fiber impregnated with epoxy resin of the same origin as the reinforcement, or nylon binding tape or polyester fiber binding tape, but galvanized iron wire that is prone to rust is strictly prohibited) to bind and fix the GFRP stirrups and GFRP longitudinal reinforcing bars at each intersection node.

[0051] The clamping and fixing system utilizes prefabricated clamping components made of resin-based composite materials whose mechanical properties and corrosion resistance are matched to those of mechanically recycled GFRP reinforcement. Each clamping component has prefabricated bidirectional limiting grooves that precisely match the cross-sectional dimensions of the longitudinal reinforcing bars and stirrups of the GFRP. The inner diameter of the grooves is an interference fit with the outer diameter of the corresponding reinforcing bars. During construction, the longitudinal reinforcing bars of the GFRP are first clamped into the longitudinal grooves of the clamping components for positioning. Then, the GFRP stirrups are clamped into the transverse grooves of the clamping components. The interference fit of the grooves achieves rigid fixing of the intersection joints.

[0052] The splicing and fixing methods are divided into two implementation forms: integral splicing of closed stirrups and splicing of joint sleeves, which can be flexibly selected according to the reinforcement configuration of the beam. For integral splicing of closed stirrups, prefabricated closed GFRP stirrups are used. The closed stirrups are integrally sleeved onto the outside of all the arranged GFRP longitudinal reinforcing bars along the beam axis. After adjusting to the design spacing, auxiliary limiting fixation is added at each intersection of the stirrups and longitudinal reinforcing bars. For splicing of joint sleeves, prefabricated sleeves made of resin-based composite material of the same origin as the reinforcing bar are used. The sleeves are set at intervals along the longitudinal reinforcing bar axis according to the design spacing of the stirrups. The sidewalls of the sleeves are prefabricated with limiting holes for the stirrups to pass through vertically. During construction, the sleeve is first inserted into the GFRP longitudinal reinforcing bar and positioned, and then the GFRP stirrup is passed through the limiting holes of the corresponding sleeve positions to achieve vertical limiting fixation of the stirrups and longitudinal reinforcing bars.

[0053] For resin consolidation and fixing, epoxy resin adhesive of the same origin as the mechanically recycled GFRP reinforcement matrix is ​​used as the consolidation material. At the intersection of GFRP stirrups and GFRP longitudinal reinforcing bars, epoxy resin adhesive is evenly applied to the contact surface so that the adhesive layer completely fills the contact gap between the reinforcing bars. After the coating is completed, temporary fasteners are used to maintain the designed position of the node. After the epoxy resin adhesive has completely cured, the temporary fasteners are removed to form a rigid node with adhesive consolidation.

[0054] In actual construction, one of the above methods can be implemented alone or in combination, depending on the stress characteristics and construction requirements of different areas of the concrete beam 1. For example, in the conventional sections of the concrete beam 1, binding fixation is used to achieve rapid construction; in the stirrup-reinforced areas and at the support ends, snap-fit ​​fixation or resin consolidation fixation is used to enhance the joint performance; for large-span beams, after the stirrups are laid out using sleeve fixation, binding fixation is used to limit the joint position, balancing construction efficiency and the structural stability of the reinforcement cage, and adapting to the construction needs of different engineering scenarios.

[0055] In one embodiment, the concrete is concrete incorporating mechanically recycled glass fibers obtained from the mechanical processing and recycling of decommissioned wind turbine blades.

[0056] The mechanically recycled glass fiber is obtained from glass fiber waste dismantled from retired wind turbine blades. It is produced through mechanical processing steps such as crushing, sorting, chopping, and impurity removal, resulting in short, discontinuous fibers. The fiber length is adapted to the requirements of concrete mixing and molding, controlled within the range of 3mm to 20mm, preferably 10mm. The amount of mechanically recycled glass fiber is 0.5% to 2% of the total mass of the concrete cementitious materials, preferably 1%. After uniform mixing, it is dispersed in the concrete matrix in a three-dimensional random state, without clumping or stacking. The glass fiber waste can be waste generated during the processing of GFRP longitudinal reinforcing bars 2 and GFRP stirrups 3.

[0057] This mechanically recycled fiber concrete can effectively inhibit the expansion of early plastic shrinkage cracks and late stress micro-cracks in concrete, significantly improve the crack resistance, ductility and interfacial transition zone performance of the concrete matrix, and enhance the overall collaborative stress-bearing capacity of the concrete and the internal GFRP reinforcement; at the same time, it further expands the scale of the consumption of waste retired wind turbine blades, and realizes the high-value recycling and utilization of all components of the wind turbine blades.

[0058] Example 1. Determination of design object and basic conditions In this example, the flexural concrete beam 1 is taken as the design object. The concrete beam 1 uses the GFRP reinforcement of waste wind turbine blades as the main longitudinal stress-bearing reinforcement, and improves the collaborative stress-bearing performance between the reinforcement and the concrete through the interface strengthening structure and the end closing structure. At the beginning of the design stage, according to the service function, stress type and design service life requirements of the concrete beam 1, the GFRP reinforced concrete beam 1 structure system is determined.

[0059] 2. Determination of concrete materials and GFRP reinforcement In the design stage of concrete materials, considering the relatively low elastic modulus of GFRP reinforcement, high crack control requirements and interface bonding performance requirements, it is ensured that the strength of the concrete after adding fibers is greater than C25, so that it can not only meet the bearing capacity requirements of the compression zone, but also be conducive to controlling the crack development in the normal service stage.

[0060] On this basis, the performance of the GFRP reinforcement obtained by crushing, sorting and mechanical processing of waste wind turbine blades is determined. The fiber volume content of the GFRP reinforcement should not be less than 60%. For the reinforcement with a diameter d < 10mm, its tensile strength should be greater than 700MPA. For the reinforcement with a diameter of 10mm < d < 20mm, its tensile strength should be greater than 600MPA. For the reinforcement with a diameter d > 22mm, its tensile strength should be greater than 500MPA. The standard value of the tensile strength of the GFRP reinforcement should have a 95% guarantee rate, and the elastic modulus and ultimate strain should be taken as the average value.

[0061] 3. Design of GFRP longitudinal stress-bearing reinforcement and flexural bearing capacity In the design process of longitudinal stress-bearing reinforcement, according to the design value of the tensile strength of the GFRP reinforcement, the number, cross-sectional dimensions and layout position of the longitudinal stress-bearing reinforcement in the beam cross-section are determined. The tensile strength of the mechanically recycled GFRP reinforcement is calculated by the following formula:

[0062] In the formula: is the design value of the tensile strength of the GFRP reinforcement; is the standard value of the tensile strength of the GFRP reinforcement; For GFRP reinforcement materials, the partial factor is 1.4 for fiber cloth and 1.25 for other GFRP reinforcement products; The environmental impact coefficient for GFRP reinforcement is given by various factors, such as 1.25 for indoor environments, 1.4 for general outdoor environments, 1.6 for marine and corrosive environments, and 1.0 for temporary concrete structures. Furthermore, GFRP reinforcement refers to GFRP reinforcement obtained from the mechanical recycling of discarded wind turbine blades. It can be composed of glass fiber (reinforcing phase) + epoxy resin + composite filler (matrix phase). The composite filler is a mixture of inorganic mineral fillers and organic modified fillers recycled from decommissioned wind turbine blades. Specifically, it includes inorganic fillers such as quartz powder, talc powder, and calcium carbonate powder separated and recovered from discarded wind turbine blades, as well as organic fillers such as phenolic resin powder and epoxy resin fragments. The composite filler accounts for 5% to 20% of the total mass of the resin matrix (epoxy resin + composite filler) and is used to improve the formability, stiffness, and interfacial bonding performance between the epoxy resin matrix and glass fiber.

[0063] The GFRP reinforcement in concrete beam 1 should meet the minimum reinforcement ratio, which can be calculated using the following formula:

[0064] In the formula: This represents the design value for the tensile strength of GFRP reinforcement. This is the design value for the tensile strength of concrete.

[0065] The flexural capacity of GFRP-reinforced concrete flexural members shall conform to the following formula:

[0066] In the formula: M is the design value of bending moment. The height of the equivalent rectangular stress diagram of the concrete compression zone. The effective stress of the GFRP reinforcement. The total cross-sectional area of ​​the GFRP reinforcement in the tension zone is... The effective height of the cross section of concrete beam 1.

[0067] When designing the tensile bearing capacity of the tension zone of a concrete beam and determining the reinforcement ratio of GFRP reinforcement, the tensile strength of the GFRP reinforcement prepared from the recycled waste wind turbine blades of this batch is first sampled and measured. Based on the measured tensile strength value, the reinforcement ratio of the longitudinal reinforcement of GFRP is dynamically adjusted on the basis of the set minimum reinforcement ratio. Then, the crack resistance performance of the concrete mixed with mechanically recycled glass fiber is coupled and checked to ensure that the reinforcement ratio of the longitudinal reinforcement of GFRP matches the actual tensile strength of the reinforcement and the crack resistance performance of the concrete, so as to ensure that the longitudinal reinforcement of GFRP and the concrete mixed with mechanically recycled glass fiber are stressed together.

[0068] During design, the spacing of the longitudinal GFRP reinforcement bars should be reasonably controlled. The clear spacing of the longitudinal GFRP reinforcement bars in the horizontal direction should not be less than 25 mm or the maximum diameter of the GFRP bars. When multiple layers of longitudinal GFRP reinforcement bars need to be arranged, the clear spacing between each layer of longitudinal GFRP reinforcement bars should not be less than 25 mm or the maximum diameter of the GFRP bars. This is to avoid brittle failure of the beam caused by sudden breakage of the longitudinal bars under the ultimate bearing state.

[0069] Considering the discreteness of the tensile strength performance of GFRP bars prepared from recycled wind turbine blades due to differences in recycled raw material batches and fluctuations in secondary processing technology, a dynamic optimization design method is adopted when determining the reinforcement ratio of the longitudinal GFRP reinforcement bars in the concrete beam body 1: First, conduct a sampling test on the tensile strength of the GFRP bars to be used in this batch. The sampling quantity should not be less than 5% of the total quantity of the bars in this batch and the single batch sampling quantity should not be less than 3 bars. After testing, obtain the average value of the measured tensile strength. If the measured average value is higher than the tensile strength standard value of the GFRP bars with the corresponding diameter (for bars with d < 10 mm, the measured average value > 700 MPa; for bars with 10 mm < d < 20 mm, the measured average value > 600 MPa; for bars with d > 22 mm, the measured average value > 500 MPa), then on the premise of meeting the minimum reinforcement ratio set for the concrete beam body 1, reduce the reinforcement ratio of the longitudinal GFRP reinforcement bars by 5% - 10%. If the measured average value is lower than the tensile strength standard value of the GFRP bars with the corresponding diameter but not lower than the tensile strength design value ( ), increase the reinforcement ratio of the longitudinal GFRP reinforcement bars by 5% - 10% based on the minimum reinforcement ratio set for the concrete beam body 1.

[0070] After the preliminary adjustment of the reinforcement ratio of the longitudinal GFRP reinforcement bars is completed, conduct a coupling check in combination with the actual crack resistance performance of the concrete mixed with mechanically recycled glass fibers in this embodiment. If the crack resistance performance of the concrete meets the design requirements of the concrete beam body 1, implement it according to the adjusted reinforcement ratio. If the crack resistance performance of the concrete is weak, then appropriately increase the reinforcement ratio of the longitudinal GFRP reinforcement bars by 3% - 5%. Finally, achieve the matching of the actual tensile strength of the GFRP bars, the reinforcement ratio of the longitudinal GFRP reinforcement bars, and the crack resistance performance of the concrete mixed with mechanically recycled glass fibers, avoid local stress failure of the concrete beam body 1 caused by inconsistent reinforcement and actual material properties, and ensure the full - process coordinated stress of the longitudinal GFRP reinforcement bars and the concrete mixed with mechanically recycled glass fibers.

[0071] 4. Design of Stirrups, Shear - Resistance Structures and Stirrup - Reinforced Zones Based on the shear requirements of the concrete beam 1 at different locations, mechanically recycled GFRP stirrups are used as shear-resistant members, and the basic spacing and arrangement of the GFRP stirrups 3 are determined. In the beam end area near the support and in the shear span zone, GFRP stirrup 3 reinforcement zones are set according to the stress characteristics. The shear capacity and ductility of the members in local areas are improved by reducing the spacing of the GFRP stirrups 3. The spacing of the GFRP stirrups 3 should not exceed 0.5 times the effective section height, and the reinforcement ratio of the GFRP stirrups 3 should not be less than the minimum reinforcement ratio. The minimum reinforcement ratio can be calculated using the following formula:

[0072] In the formula: The minimum reinforcement ratio for GFRP stirrups 3; This represents the minimum cross-sectional area of ​​all stirrups within the same cross-section. b is the width of the rectangular cross-section, the web width of the T-shaped or I-shaped cross-section, and s is the spacing of the stirrups or threaded bars along the length of the member.

[0073] The shear capacity of the inclined section of a concrete member using GFRP bars as stirrups shall conform to the following formula:

[0074] In the formula V The design shear force (kN) V C The design value of the shear force (kN) borne by concrete. V f The design value of the shear force (kN) borne by the stirrups; f t Here, is the design value of the tensile strength of the concrete; b is the width of the rectangular section (full width for rectangular sections, web width for T-shaped / I-shaped sections); c is the distance from the neutral axis of the section (the neutral axis is the dividing line between tensile and compressive stresses within the concrete beam 1 under bending stress, and also an imaginary axis where the normal stress in the beam section is zero, parallel to the length of the concrete beam 1 and perpendicular to the cross-sectional direction) to the edge of the compression zone; k is the ratio of the distance from the neutral axis of the section to the edge of the compression zone to the effective height. This is the ratio of the elastic modulus of GFRP reinforcement to the elastic modulus of concrete. This represents the longitudinal reinforcement ratio of GFRP reinforcement.

[0075] The GFRP stirrups 3 and the longitudinal reinforcing bars form a stable connection node through binding, snap-fitting or sleeve connection. The two ends of the concrete beam 1 are designed with a denser zone so that the GFRP longitudinal reinforcing bars 2 and GFRP stirrups 3 together form an integral reinforcement skeleton system, thereby ensuring the structural stability of the beam during construction and service.

[0076] 5. Design of protective layer thickness and structural reinforcement 4 During the design of the protective layer thickness, the corrosion resistance, interfacial bonding requirements, and construction feasibility of the GFRP reinforcement are comprehensively considered to determine the concrete protective layer thickness of the GFRP longitudinal reinforcing bar 2. The minimum protective layer thickness should not be less than 20mm. This ensures that the GFRP longitudinal reinforcing bar 2 meets durability requirements while also providing good interfacial stress conditions.

[0077] To further improve the stability of the reinforcement cage during construction and reduce the displacement or deformation of the GFRP longitudinal reinforcement 2 during pouring and vibration, structural reinforcement 4 is installed at specific locations in the concrete beam 1. The structural reinforcement 4 can be arranged along the height or length of the concrete beam 1 and connects with the GFRP longitudinal reinforcement 2 or GFRP stirrups 3. It is used to assist in positioning the GFRP longitudinal reinforcement 2, stabilize the reinforcement cage shape, and improve the structural integrity of the beam. 6. Construction, Realization, and Formulation of the Design Result After completing the design of the concrete beam 1, according to the determined material parameters and structural requirements, positioning components are set in the concrete beam formwork to control the position of the GFRP longitudinal reinforcing bars 2 and the thickness of the protective layer. Then, the erection of the GFRP longitudinal reinforcing bars 2, the installation of the GFRP stirrups 3 and GFRP structural bars 4, the confirmation of the interface reinforcement structure, and the setting of the end closing components are completed in sequence to form a reinforcing skeleton structure consistent with the design results.

[0078] Subsequently, the mechanically recycled fiber reinforced concrete is poured into the formwork, so that the concrete covers the reinforcing skeleton and fills the forming space. After vibration and curing, a concrete beam component 1 is formed using GFRP reinforcing material recycled from retired wind turbine blades.

[0079] In summary, for comparison, the density of ordinary steel reinforcement is approximately 7.9 g / cm³, while that of GFRP reinforcement is approximately 2.0 g / cm³. Under the same volume conditions, GFRP reinforcement can achieve a weight reduction of approximately 74.7%. The tensile strength of ordinary steel reinforcement is approximately 400 MPa, while that of GFRP reinforcement is approximately 500-700 MPa. Under reasonable reinforcement and material matching conditions, the ultimate load of beam members can be increased by 19.3%–20.6%, and the maximum crack width can be reduced by 34.5%–50.9%. After increasing the actual reinforcement ratio, the bearing capacity can be further increased by 8.4%. Furthermore, seawater and sea sand concrete beam tests show that after incorporating GFRP reinforcement, the ultimate bearing capacity of the beam increases with the increase of the equivalent reinforcement ratio, and it can improve the problem of insufficient ductility in pure GFRP reinforced beams.

[0080] Secondly, this application provides a design method for a GFRP-reinforced concrete beam made from recycled GFRP reinforcement from decommissioned wind turbine blades, applicable to the aforementioned GFRP-reinforced concrete beam made from decommissioned wind turbine blades, comprising: Based on the stress requirements of the concrete beam, determine the concrete strength grade to incorporate fibers, and then incorporate short-cut fibers or mechanically recycled fiber reinforcement materials into the concrete based on the concrete strength grade. Based on the GFRP reinforcement prepared from recycled waste wind turbine blades, the mechanical properties of the GFRP reinforcement are determined, and the mechanical properties are used as the design basis for the tensile members of the concrete beam. The mechanical properties include its tensile strength, elastic modulus and ultimate strain. Based on the concrete strength grade and the mechanical properties of the GFRP reinforcement, the tensile bearing capacity of the tension zone of the concrete beam is designed, the required reinforcement cross-sectional area is calculated, and the reinforcement ratio of the GFRP reinforcement is not less than the set minimum reinforcement ratio, so as to obtain the cross-sectional area of ​​the longitudinal reinforcement of GFRP. Based on the shear force requirements of the concrete beam, the material type, diameter, and spacing of the stirrups are determined, and stirrups are set in the shear force control zone of the concrete beam to obtain the material type, location, diameter, and spacing of the GFRP stirrups.

[0081] Thirdly, this application provides a construction method for a concrete beam reinforced with recycled GFRP (Glass Reinforced Polymer) for decommissioned wind turbine blades, applicable to the aforementioned concrete beam reinforced with recycled GFRP for decommissioned wind turbine blades, comprising: The glass fiber material in the waste wind turbine blades is processed to obtain GFRP longitudinal reinforcing bars and GFRP stirrups, and an interface reinforcement structure is formed on the outer surface of the GFRP longitudinal reinforcing bars. A closing member body 5 is installed at at least one end of the GFRP longitudinal reinforcing rib, so that the closing member body 5 covers the opening of the GFRP longitudinal reinforcing rib and forms a closed structure; The GFRP longitudinal reinforcing bars are arranged according to the reinforcement requirements of the concrete beam section, and the GFRP stirrups are spaced apart along the length of the concrete beam to form a reinforcement skeleton by being fixedly connected with the GFRP longitudinal reinforcing bars. According to the design layout requirements, the GFRP longitudinal reinforcing bars and the GFRP stirrups are positioned, and the GFRP stirrups are fixed to the outside of the GFRP longitudinal reinforcing bars by at least one of the following methods: binding, snapping, sleeve connection or resin consolidation, to form a reinforcing skeleton. Then, the concrete beam formwork is installed, and the reinforcing skeleton is placed inside the concrete beam formwork so that the reinforcing skeleton is kept in a predetermined position inside the concrete beam formwork. Concrete is poured into the concrete beam formwork to cover the reinforcing skeleton and fill the gap between the concrete beam formwork and the reinforcing skeleton. The concrete beam is cured during the initial setting and hardening process. After the concrete beam reaches the predetermined strength, the concrete beam formwork is removed to form a concrete beam based on the GFRP reinforcement of discarded wind turbine blades.

[0082] Among the feasible methods, the curing of the concrete beam during or before the initial setting and hardening of the concrete beam includes: During or after the concrete pouring process, the concrete is vibrated to remove air bubbles and make it dense.

[0083] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A concrete beam with recycled GFRP reinforcement from decommissioned wind turbine blades, characterized in that, include: Concrete beams; The reinforcing skeleton, arranged within the concrete beam, includes at least two GFRP longitudinal reinforcing bars arranged along the length of the concrete beam, and GFRP stirrups fixedly connected to the GFRP longitudinal reinforcing bars and spaced apart along the length of the concrete beam; wherein, both the GFRP longitudinal reinforcing bars and the GFRP stirrups are made from waste wind turbine blade composite materials through mechanical recycling.

2. The GFRP reinforced concrete beam with recycled decommissioned wind turbine blades as described in claim 1, characterized in that, The outer surface of the GFRP longitudinal reinforcing bar is provided with an interface reinforcement structure, which is one or more of the following: spiral embossing, longitudinal groove, and surface roughening layer.

3. The GFRP-reinforced concrete beam with recycled decommissioned wind turbine blades as described in claim 1, characterized in that, The GFRP longitudinal reinforcing bars are provided with sealing bodies at both ends to seal the openings at the bar ends and prevent slurry or particles from entering the interior of the bar ends.

4. The GFRP-reinforced concrete beam with recycled decommissioned wind turbine blades as described in claim 3, characterized in that, The closure body is made of resin-based composite material, polymer material or metal material.

5. The GFRP reinforced concrete beam with recycled decommissioned wind turbine blades as described in claim 1, characterized in that, The matrix material of the GFRP longitudinal reinforcing bars and the GFRP stirrups is made of glass fiber, epoxy resin and composite filler from waste wind turbine blades, wherein the mass ratio of glass fiber in the matrix material is not less than 60%.

6. The GFRP-reinforced concrete beam with recycled decommissioned wind turbine blades as described in claim 1, characterized in that, The concrete is concrete mixed with glass fibers obtained from the mechanical processing and recycling of decommissioned wind turbine blades.

7. The GFRP-reinforced concrete beam with recycled decommissioned wind turbine blades as described in claim 1, characterized in that, The GFRP stirrups and GFRP longitudinal reinforcing bars are fixedly connected by at least one of the following methods: binding, snap-fitting, sleeve-fitting, or resin consolidation, to form an integral reinforcing skeleton structure.

8. A design method for a concrete beam using recycled GFRP reinforcement from decommissioned wind turbine blades, characterized in that, The concrete beam with recycled GFRP reinforcement for decommissioned wind turbine blades as described in any one of claims 1-7 comprises: Based on the stress requirements of the concrete beam, determine the concrete strength grade to incorporate fibers, and incorporate recycled short-cut fibers or fiber-reinforced materials into the concrete based on the concrete strength grade. Based on the GFRP reinforcement prepared from recycled waste wind turbine blades, the mechanical properties of the GFRP reinforcement are determined, and the mechanical properties are used as the design basis for the tensile members of the concrete beam. The mechanical properties include its tensile strength, elastic modulus and ultimate strain. Based on the concrete strength grade and the mechanical properties of the GFRP reinforcement, the tensile bearing capacity of the tension zone of the concrete beam is designed, the required reinforcement cross-sectional area is calculated, and the reinforcement ratio of the GFRP reinforcement is not less than the set minimum reinforcement ratio, so as to obtain the cross-sectional area of ​​the longitudinal reinforcement of GFRP. Based on the shear force requirements of the concrete beam, the material type, diameter, and spacing of the stirrups are determined, and stirrups are set in the shear force control zone of the concrete beam to obtain the material type, location, diameter, and spacing of the GFRP stirrups.

9. A construction method for a concrete beam using recycled GFRP reinforcement from decommissioned wind turbine blades, characterized in that, The concrete beam with recycled GFRP reinforcement for decommissioned wind turbine blades as described in any one of claims 1-7 comprises: The glass fiber material in the waste wind turbine blades is processed to obtain GFRP longitudinal reinforcing bars and GFRP stirrups, and an interface reinforcement structure is formed on the outer surface of the GFRP longitudinal reinforcing bars. A closing member body is installed at at least one end of the GFRP longitudinal reinforcing rib, so that the closing member body covers the opening of the GFRP longitudinal reinforcing rib and forms a closed structure; The GFRP longitudinal reinforcing bars are arranged according to the reinforcement requirements of the concrete beam section, and the GFRP stirrups are spaced apart along the length of the concrete beam to form a reinforcement skeleton by being fixedly connected with the GFRP longitudinal reinforcing bars. According to the design layout requirements, the GFRP longitudinal reinforcing bars and the GFRP stirrups are positioned, and the GFRP stirrups are fixed to the outside of the GFRP longitudinal reinforcing bars by at least one of the following methods: binding, snapping, sleeve connection or resin consolidation, to form a reinforcing skeleton. Then, the concrete beam formwork is installed, and the reinforcing skeleton is placed inside the concrete beam formwork so that the reinforcing skeleton is kept in a predetermined position inside the concrete beam formwork. Concrete is poured into the concrete beam formwork to cover the reinforcing skeleton and fill the gap between the concrete beam formwork and the reinforcing skeleton. The concrete beam is cured during the initial setting and hardening process. After the concrete beam reaches the predetermined strength, the concrete beam formwork is removed to form a concrete beam based on the GFRP reinforcement of discarded wind turbine blades.

10. The construction method for a GFRP-reinforced concrete beam made from recycled decommissioned wind turbine blades as described in claim 9, characterized in that, The curing of concrete beams during or before the initial setting and hardening process includes: During or after the concrete pouring process, the concrete is vibrated to remove air bubbles and make it dense.

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