3D printing FRP profile self-compacting fiber concrete beam structure
By using 3D-printed FRP profiles to construct self-compacting fiber-reinforced concrete beam structures, and utilizing FRP reinforcing bars and interwoven mesh layers, combined with modified fibers and additives, the problems of heavy weight and insufficient mechanical properties of concrete beam structures have been solved, achieving improvements in lightweight, high strength, and durability.
Patent Information
- Application Number
- CN202511207932.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-27
- Publication Date
- 2025-11-28
AI Technical Summary
Existing concrete beam structures are heavy and prone to cracking. FRP composite materials can improve mechanical properties when bonded to concrete, but the mechanical properties of commercially available concrete are insufficient and need to be further improved.
3D printing technology was used to prepare FRP profile self-compacting fiber reinforced concrete beam structures. The FRP reinforcement mesh layer formed by the interlacing of FRP stiffeners, ribs and FRP bars, combined with modified fibers and functional additives, improved the mechanical properties and durability of the concrete.
It achieves lightweight, high-strength, and corrosion-resistant concrete beam structures with excellent stability and significantly improved load-bearing and durability.
Smart Images
Figure CN121024257A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of building structures, in particular to a 3D printing FRP profile self-compacting fiber concrete beam structure. BACKGROUND
[0002] In recent years, more and more people have begun to pay attention to the application of 3D printing technology in concrete buildings. The 3D printing technology can greatly improve the construction speed and work efficiency of buildings, and can also reduce the construction cost. Furthermore, the 3D printing concrete technology cancels the cumbersome procedures of formwork erection and formwork removal in the construction process, greatly simplifies the construction process, can improve the construction speed by more than 10 times, can realize full utilization of concrete, can reduce the use amount of cement, can improve the service life of buildings, can reduce the generation of construction waste, and can reduce repeated construction. In addition, the 3D printing concrete technology can realize the printing of various shape buildings, has small requirements on the environment, and can be applied to the exploration of outer space and rapid completion of space base construction.
[0003] Although the concrete beam structure provided by the prior art has good mechanical properties, the concrete beam structure has a large self-weight and is prone to cracking. The FRP composite material is a high-performance material formed by mixing fiber materials and matrix materials (resin) in a certain proportion. The FRP composite material has the advantages of light weight, hardness and high mechanical strength, and the use of the FRP composite material with concrete can effectively improve the mechanical properties of the concrete, so the FRP composite material is widely applied to various civil buildings, bridges, highways, oceans, hydraulic structures and underground structures. However, the quality of the concrete beam structure is largely dependent on the quality of the concrete itself. Although the commercially available concrete has the advantages of low cost and good durability, the mechanical properties of the concrete itself are relatively insufficient and still need to be further improved. SUMMARY
[0004] The application aims to provide a 3D printing FRP profile self-compacting fiber concrete beam structure. The 3D printing FRP profile self-compacting fiber concrete beam structure has good mechanical properties, light weight, high strength and corrosion resistance. The synergistic effect between the FRP reinforcing bars, the ribbed plates and the FRP reinforcing net layers formed by the longitudinal and transverse interweaving of the FRP bars can not only ensure the stability of the concrete beam structure, but also further improve the load and durability of the concrete beam structure, and effectively ensure the quality of the concrete beam structure.
[0005] To achieve the above-mentioned purpose, the application provides the following technical scheme.
[0006] The application discloses a 3D printing FRP profile self-compacting fiber concrete beam structure, which comprises a prefabricated FRP profile which is an integrated structure; the prefabricated FRP profile is composed of a top plate, a bottom plate, a rib plate and FRP reinforcing bars arranged on both sides of the rib plate; the FRP reinforcing bars are linearly arranged along the length direction of the rib plate; the bottom plate and the top plate are connected through the rib plate arranged at the middle part of the bottom plate and the top plate; self-compacting fiber concrete is poured into mounting grooves at the top of the top plate and the bottom plate; and a FRP reinforcing net layer formed by vertically and horizontally interlaced FRP bars is horizontally embedded in the self-compacting fiber concrete.
[0007] Further, the concrete is made of the following raw materials by weight: 80-100 parts of cement, 260-320 parts of gravel, 220-250 parts of sand, 35-50 parts of fly ash, 25-35 parts of silica powder, 10-15 parts of zeolite powder, 8-12 parts of steel fiber, 12-17 parts of limestone, 1.5-3 parts of sodium polyacrylate, 10-15 parts of modified fiber, 3.5-5.5 parts of functional additive, 2.5-6 parts of water reducing agent, 1-1.5 parts of defoaming agent, 0.7-1.2 parts of thickening agent and 80-110 parts of water.
[0008] Further, the preparation method of the modified fiber comprises the following steps:
[0009] Step one, the cleaned polypropylene fiber is put into a light-transmitting reactor, and then dimethylbenzene with a mass of 8-12 times of the polypropylene fiber, dehydrated malonic acid anhydride with a mass of 3-8 times of the polypropylene fiber and benzoylbenzene with a mass of 0.2-0.3 times of the polypropylene fiber are sequentially added, the mixture is uniformly stirred, and then the mixture is statically placed at 40-50 DEG C for 20-30 hours; then nitrogen is filled into the light-transmitting reactor to remove oxygen in the light-transmitting reactor, the light-transmitting reactor is sealed, and the reaction is carried out under the condition of ultraviolet light irradiation for 5-8 hours; after the reaction is completed, the polypropylene fiber is filtered out, cleaned with acetone, and then dried in a vacuum drying box until the weight is constant; the obtained primary modified polypropylene fiber is stored and reserved;
[0010] Step two, the primary modified polypropylene fiber is immersed in anhydrous ethanol according to a solid-liquid ratio of 0.05-0.1 g / mL, then 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide with a mass of 0.5-0.8 times of the primary modified polypropylene fiber and diethylenetriamine with a mass of 6-12 times of the primary modified polypropylene fiber are sequentially added to the obtained mixture; the mixture is uniformly stirred, and then refluxed for 5-8 hours; after the reaction is completed, the obtained product is filtered, washed with acetone and distilled water for 2-3 times respectively, and then dried until the weight is constant; the obtained product is recorded as secondary modified polypropylene fiber; the secondary modified polypropylene fiber is stored and reserved;
[0011] Step 3: Disperse the secondary modified polypropylene fiber evenly in N,N-dimethylformamide at a solid-liquid ratio of 0.01-0.02 g / mL. Add 1,2-ethanedicarboxylic acid (5-10 times the mass of the secondary modified polypropylene fiber) and 1-(3-dimethylaminopropyl)-3-ethylcarboimide (0.3-0.6 times the mass of the secondary modified polypropylene fiber) in sequence. Mix and stir until the 1,2-ethanedicarboxylic acid is completely dissolved. Then heat the resulting mixture to 90-100℃ and keep it at this temperature for 5-8 hours. After the reaction is complete, separate the reaction product into solid and liquid components. Wash the obtained solid filter material with acetone and distilled water 2-3 times and dry it to constant weight. The final product is the modified fiber.
[0012] Furthermore, the preparation method of the functional additive is as follows:
[0013] I. Mix anhydrous calcium sulfate and aminoformaldehyde evenly at a weight ratio of 5-8:1. Then add 20-30% by weight of silica sol to the resulting first mixture and stir evenly. Then add 10-25 times the weight of deionized water to the resulting second mixture and mechanically disperse evenly. Adjust the pH to 5.8-7.3. Then introduce nitrogen gas into the resulting reaction system and keep it at 25-35°C for 3-5 hours. After the reaction is complete, let it cool naturally to room temperature. Store the resulting product components for later use.
[0014] II. Add 4-8% sodium alginate by mass to the product component obtained in step I, mix and stir evenly, and keep it at 45-55℃ for 4-7 hours. After the reaction is completed, cool it naturally to room temperature, and then freeze-dry it for 20-30 hours to obtain the functional additive.
[0015] Furthermore, the water-reducing agent is selected from any one of polycarboxylate water-reducing agents, naphthalene-based water-reducing agents, and sodium gluconate water-reducing agents.
[0016] Furthermore, the defoamer is selected from either polyoxyethylene polyoxypropylene amine ether or polyoxypropylene glycerol ether.
[0017] Furthermore, the thickener is selected from any one of polyacrylamide, cellulose ether, and polyvinyl alcohol.
[0018] Furthermore, the cleaning process for the polypropylene fiber is as follows: the polypropylene fiber is soaked in acetone for 5 to 8 hours at a dosage ratio of 0.03 to 0.08 g / mL; then it is taken out, washed with distilled water, and transferred to a vacuum drying oven for drying. After drying, the cleaning process for the polypropylene fiber is completed.
[0019] Furthermore, the prefabricated FRP profiles and FRP ribs are made of any one of basalt fiber, glass fiber, or carbon fiber.
[0020] Compared with the prior art, the beneficial effects of the present invention are:
[0021] 1. In this invention, polypropylene fiber, dehydrated malic anhydride, and benzoylbenzene are used as raw materials. A reaction occurs under ultraviolet light irradiation, ultimately forming bonds between the polypropylene fiber and the dehydrated malic anhydride, thus preparing primary modified polypropylene fiber. The primary modified polypropylene fiber is immersed in anhydrous ethanol, and 1-(3-dimethylaminopropyl)-3-ethylcarboimide and diethylenetriamine are added. After mixing and stirring evenly, a reflux reaction is carried out, effectively extending the length of the dehydrated malic anhydride molecular chain to obtain secondary modified polypropylene fiber. The obtained secondary modified polypropylene fiber is uniformly dispersed in N,N-dimethylformamide, and 1,2-ethanedicarboxylic acid and 1-(3-dimethylaminopropyl)-3-ethylcarboimide are added. Through a chemical reaction, 1,2-ethanedicarboxylic acid is effectively "grafted" onto the molecular chain of the secondary modified polypropylene fiber, yielding the modified fiber product. The modified fibers prepared by this invention have abundant highly reactive groups on their surface, which can chemically react with relevant groups in cement slurry, effectively improving the anchoring effect of cement materials on the modified fibers. Furthermore, the surface roughness of the modified fibers is significantly improved, resulting in a tighter interlocking with the cement materials and effectively ensuring the mechanical properties of the concrete.
[0022] 2. In this invention, anhydrous calcium sulfate and aminoformaldehyde are used as raw materials. Silica sol is added and mixed thoroughly, then the mixture is kept at a constant temperature for reaction. After the reaction is complete, sodium alginate is added, and the mixture is kept at a constant temperature for further reaction, followed by freeze-drying to obtain the final functional additive. This functional additive not only undergoes a complexation reaction with the mineral components in cement, accelerating the hardening speed of the cement paste, but also effectively enhances the density of the cement paste and improves its early strength. Furthermore, the nanoparticles in the silica sol can act as nuclei for crystal formation after cement hydration, further improving the density of the cement and ensuring the mechanical properties of the concrete.
[0023] 3. The concrete beam structure provided by this invention has advantages such as light weight, high strength, and corrosion resistance. Specifically, the synergistic effect of the FRP reinforcing ribs, ribs, and the FRP reinforcement mesh layer formed by the interlacing of FRP bars not only ensures the stability of the concrete beam structure but also further improves its load-bearing capacity and durability, effectively guaranteeing its quality. Attached Figure Description
[0024] Figure 1 A structural schematic diagram of a 3D-printed FRP profile self-compacting fiber-reinforced concrete beam structure;
[0025] In the diagram: 1-Precast FRP profile, 101-Top plate, 102-Bottom plate, 103-Rib plate, 104-FRP reinforcing rib, 105-Mounting groove;
[0026] 2-Self-compacting fiber-reinforced concrete;
[0027] 3-FRP reinforcing bars;
[0028] 4-FRP reinforced mesh layer. Detailed Implementation
[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0030] Example 1
[0031] A 3D-printed FRP profile self-compacting fiber-reinforced concrete 2-beam structure is disclosed. The concrete beam structure includes a prefabricated FRP profile 1, which is an integrally formed structure. The prefabricated FRP profile 1 consists of a top plate 101, a bottom plate 102, ribs 103, and FRP reinforcing ribs 104 located on both sides of the ribs 103. The FRP reinforcing ribs 104 are linearly arranged along the length of the ribs 103. The bottom plate 102 and the top plate 101 are connected by the ribs 103 located in the middle of the bottom plate 102. Self-compacting fiber-reinforced concrete 2 is poured into the mounting grooves 105 at the top of the top plate 101 and the bottom plate 102. An FRP reinforcing mesh layer 4 formed by interlacing FRP ribs 3 is horizontally embedded in the self-compacting fiber-reinforced concrete 2.
[0032] Among them, the precast FRP profile 1 and FRP rib 3 are made of basalt fiber.
[0033] The concrete is made from the following raw materials in parts by weight: 80 parts P.I52.5 silicate cement, 260 parts crushed stone, 220 parts sand, 35 parts fly ash, 25 parts silica fume, 10 parts zeolite powder, 8 parts steel fiber, 12 parts limestone, 1.5 parts sodium polyacrylate, 10 parts modified fiber, 3.5 parts functional additives, 2.5 parts polycarboxylate superplasticizer, 1 part polyoxyethylene polyoxypropylene amine ether, 0.7 parts polyacrylamide, and 80 parts water.
[0034] The method for preparing modified fibers includes the following steps:
[0035] Step 1: Place the cleaned polypropylene fiber into a light-transmitting reactor, and sequentially add xylene (8 times the mass of the polypropylene fiber), dehydrated malic anhydride (3 times the mass of the polypropylene fiber), and benzoylbenzene (0.2 times the mass of the polypropylene fiber). Mix and stir evenly, and let stand at 40°C for 20 hours. Then, purge the oxygen from the light-transmitting reactor with nitrogen gas, seal the reactor, and react under ultraviolet light irradiation for 5 hours. After the reaction is complete, filter out the polypropylene fiber, wash it with acetone, and then transfer it to a vacuum drying oven to dry to constant weight. Store the obtained primary modified polypropylene fiber for later use.
[0036] Step 2: Immerse the primary modified polypropylene fiber in anhydrous ethanol at a solid-liquid ratio of 0.05 g / mL. Then, add 1-(3-dimethylaminopropyl)-3-ethylcarboimide (0.5 times the mass of the primary modified polypropylene fiber) and diethylenetriamine (6 times the mass of the primary modified polypropylene fiber) sequentially to the resulting mixture. After mixing and stirring evenly, reflux for 5 hours. After the reaction is complete, filter the resulting product and wash it twice with acetone and distilled water, respectively. Then, dry it to constant weight. The result is called secondary modified polypropylene fiber. Store it for later use.
[0037] Step 3: Disperse the secondary modified polypropylene fiber evenly in N,N-dimethylformamide at a solid-liquid ratio of 0.01 g / mL. Add 1,2-ethanedicarboxylic acid (5 times the mass of the secondary modified polypropylene fiber) and 1-(3-dimethylaminopropyl)-3-ethylcarboimide (0.3 times the mass of the secondary modified polypropylene fiber) in sequence. Mix and stir until the 1,2-ethanedicarboxylic acid is completely dissolved. Then heat the resulting mixture to 90°C and keep it at this temperature for 5 hours. After the reaction is complete, separate the reaction product into solid and liquid components. Wash the obtained solid filter material twice with acetone and distilled water, and then dry it to constant weight. The final product is the modified fiber.
[0038] The preparation method of the functional additive is as follows:
[0039] I. Mix anhydrous calcium sulfate and aminoformaldehyde evenly at a weight ratio of 5:1. Then add 20% of the mass of silica sol to the resulting first mixture and stir evenly. Then add 10 times the mass of deionized water to the resulting second mixture and mechanically disperse evenly. Adjust the pH to 5.8. Then introduce nitrogen gas into the resulting reaction system and keep it at 25°C for 3 hours. After the reaction is complete, let it cool naturally to room temperature. Store the resulting product components for later use.
[0040] II. Add 4% sodium alginate by mass to the product component obtained in step I, mix and stir evenly, and keep it at 45°C for 4 hours. After the reaction is completed, cool it naturally to room temperature, and then freeze-dry it for 20 hours to obtain the functional additive.
[0041] The cleaning process for polypropylene fibers is as follows: Soak the polypropylene fibers in acetone for 5 hours at a dosage ratio of 0.03 g / mL; then take them out, wash them with distilled water, and transfer them to a vacuum drying oven for drying. After drying, the cleaning process for polypropylene fibers is complete.
[0042] Example 2
[0043] The difference from Example 1 is that the specific composition of the concrete used in this example is different. The specific composition of the concrete in this example is as follows:
[0044] The concrete is made from the following raw materials in parts by weight: 90 parts cement, 300 parts crushed stone, 240 parts sand, 45 parts fly ash, 30 parts silica fume, 12 parts zeolite powder, 10 parts steel fiber, 15 parts limestone, 2.5 parts sodium polyacrylate, 12 parts modified fiber, 4.5 parts functional additives, 5 parts polycarboxylate superplasticizer, 1.2 parts polyoxyethylene polyoxypropylene amine ether, 1.0 part polyacrylamide, and 100 parts water.
[0045] The method for preparing modified fibers includes the following steps:
[0046] Step 1: Place the cleaned polypropylene fiber into a light-transmitting reactor, and sequentially add xylene (10 times the mass of the polypropylene fiber), dehydrated malic anhydride (5 times the mass of the polypropylene fiber), and benzoylbenzene (0.25 times the mass of the polypropylene fiber). Mix and stir evenly, and let stand at 45°C for 25 hours. Then, purge the oxygen from the light-transmitting reactor with nitrogen gas, seal the reactor, and react under ultraviolet light irradiation for 6 hours. After the reaction is complete, filter out the polypropylene fiber, wash it with acetone, and then transfer it to a vacuum drying oven to dry to constant weight. Store the obtained primary modified polypropylene fiber for later use.
[0047] Step 2: Immerse the primary modified polypropylene fiber in anhydrous ethanol at a solid-liquid ratio of 0.08 g / mL. Then, add 1-(3-dimethylaminopropyl)-3-ethylcarboimide (0.6 times the mass of the primary modified polypropylene fiber) and diethylenetriamine (9 times the mass of the primary modified polypropylene fiber) sequentially to the resulting mixture. After mixing and stirring evenly, reflux for 6 hours. After the reaction is complete, filter the resulting product and wash it three times with acetone and distilled water respectively. Dry it to constant weight. The result is called secondary modified polypropylene fiber. Store it for later use.
[0048] Step 3: Disperse the secondary modified polypropylene fiber evenly in N,N-dimethylformamide at a solid-liquid ratio of 0.015 g / mL. Add 1,2-ethanedicarboxylic acid (8 times the mass of the secondary modified polypropylene fiber) and 1-(3-dimethylaminopropyl)-3-ethylcarboimide (0.5 times the mass of the secondary modified polypropylene fiber) sequentially. Mix and stir until the 1,2-ethanedicarboxylic acid is completely dissolved. Then heat the resulting mixture to 95°C and keep it at this temperature for 6 hours. After the reaction is complete, separate the reaction product into solid and liquid components. Wash the obtained solid filter material three times with acetone and distilled water, and then dry it to constant weight. The final product is the modified fiber.
[0049] The preparation method of the functional additive is as follows:
[0050] I. Mix anhydrous calcium sulfate and aminoformaldehyde evenly at a weight ratio of 6:1. Then add 25% of the mass of silica sol to the first mixture and mix evenly. Then add 20 times the mass of deionized water to the second mixture and mechanically disperse evenly. Adjust the pH to 6.5. Then introduce nitrogen gas into the reaction system and keep it at 30°C for 4 hours. After the reaction is complete, let it cool naturally to room temperature. Store the resulting product components for later use.
[0051] II. Add 6% sodium alginate by mass to the product component obtained in step I, mix and stir evenly, and keep it at 50°C for 5 hours. After the reaction is completed, cool it naturally to room temperature, and then freeze-dry it for 25 hours to obtain the functional additive.
[0052] Example 3
[0053] The difference from Example 1 is that the specific composition of the concrete used in this example is different. The specific composition of the concrete in this example is as follows:
[0054] Concrete is made from the following raw materials in parts by weight: 100 parts cement, 320 parts crushed stone, 250 parts sand, 50 parts fly ash, 35 parts silica fume, 15 parts zeolite powder, 12 parts steel fiber, 17 parts limestone, 3 parts sodium polyacrylate, 15 parts modified fiber, 5.5 parts functional additives, 6 parts polycarboxylate superplasticizer, 1.5 parts polyoxyethylene polyoxypropylene amine ether, 1.2 parts polyacrylamide, and 110 parts water.
[0055] The preparation method of modified fibers includes the following steps:
[0056] Step 1: Place the cleaned polypropylene fiber into a light-transmitting reactor, and sequentially add xylene (12 times the mass of the polypropylene fiber), dehydrated malic anhydride (8 times the mass of the polypropylene fiber), and benzoylbenzene (0.3 times the mass of the polypropylene fiber). Mix and stir evenly, and let stand at 50°C for 30 hours. Then, purge the oxygen from the light-transmitting reactor with nitrogen gas, seal the reactor, and react under ultraviolet light irradiation for 8 hours. After the reaction is complete, filter out the polypropylene fiber, wash it with acetone, and then transfer it to a vacuum drying oven to dry to constant weight. Store the obtained primary modified polypropylene fiber for later use.
[0057] Step 2: Immerse the primary modified polypropylene fiber in anhydrous ethanol at a solid-liquid ratio of 0.1 g / mL. Then, add 1-(3-dimethylaminopropyl)-3-ethylcarboimide (0.8 times the mass of the primary modified polypropylene fiber) and diethylenetriamine (12 times the mass of the primary modified polypropylene fiber) sequentially to the resulting mixture. After mixing and stirring evenly, reflux for 8 hours. After the reaction is complete, filter the resulting product and wash it three times with acetone and distilled water respectively. Dry it to constant weight. The result is called secondary modified polypropylene fiber. Store it for later use.
[0058] Step 3: Disperse the secondary modified polypropylene fiber evenly in N,N-dimethylformamide at a solid-liquid ratio of 0.02 g / mL. Add 1,2-ethanedicarboxylic acid (10 times the mass of the secondary modified polypropylene fiber) and 1-(3-dimethylaminopropyl)-3-ethylcarboimide (0.6 times the mass of the secondary modified polypropylene fiber) sequentially. Mix and stir until the 1,2-ethanedicarboxylic acid is completely dissolved. Then heat the resulting mixture to 100℃ and keep it at this temperature for 8 hours. After the reaction is complete, separate the reaction product into solid and liquid components. Wash the obtained solid filter material three times with acetone and distilled water, and then dry it to constant weight. The final product is the modified fiber.
[0059] The preparation method of the functional additive is as follows:
[0060] I. Mix anhydrous calcium sulfate and aminoformaldehyde evenly at a weight ratio of 8:1. Then add 30% of the mass of silica sol to the first mixture and mix evenly. Then add 25 times the mass of deionized water to the second mixture and mechanically disperse evenly. Adjust the pH to 7.3. Then introduce nitrogen gas into the reaction system and keep it at 35°C for 5 hours. After the reaction is complete, let it cool naturally to room temperature. Store the resulting product components for later use.
[0061] II. Add 8% sodium alginate by mass to the product component obtained in step I, mix and stir evenly, and keep it at 55°C for 7 hours. After the reaction is completed, cool it naturally to room temperature, and then freeze-dry it for 30 hours to obtain the functional additive.
[0062] Comparative Example 1: The difference from Example 1 is that an equal amount of polypropylene fiber is used instead of the modified fiber in this example;
[0063] Comparative Example 2: The difference from Example 1 is that an equal amount of anhydrous calcium sulfate is used to replace the functional additive in this example.
[0064] Performance Testing: The concrete beam structures provided by Examples 1-3 and Comparative Examples 1-2 were labeled as Examples 1-3 and Comparative Examples 1-2, respectively. The relevant performance of the concrete beam structure samples provided by Examples 1-3 and Comparative Examples 1-2 were tested, and the test results are recorded in the table below:
[0065] By comparing and analyzing the relevant data in the table, it can be seen that the 3D-printed FRP profile self-compacting fiber reinforced concrete beam structure provided by this invention not only possesses good mechanical properties, but also has advantages such as light weight, high strength, and corrosion resistance. Specifically, the synergistic effect of the FRP reinforcing ribs, ribs, and the FRP reinforcement mesh layer formed by the interlacing of FRP ribs not only ensures the stability of the concrete beam structure but also further improves its load-bearing capacity and durability, effectively guaranteeing its quality. This indicates that the concrete beam structure provided by this invention has a broader market prospect and is more suitable for widespread application.
[0066] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0067] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A 3D-printed FRP profile self-compacting fiber-reinforced concrete beam structure, characterized in that: The concrete beam structure includes precast FRP profiles, which are integrally formed structures. The precast FRP profiles consist of a top plate, a bottom plate, ribs, and FRP reinforcing bars located on both sides of the ribs. The FRP reinforcing bars are linearly arranged along the length of the ribs. The bottom plate and the top plate are connected by ribs located in the middle of the bottom plate. Self-compacting fiber concrete is poured into the mounting grooves at the top of the top plate and the bottom plate, and an FRP reinforcement mesh layer formed by interlacing FRP bars is horizontally embedded in the self-compacting fiber concrete.
2. The 3D-printed FRP profile self-compacting fiber reinforced concrete beam structure according to claim 1, characterized in that, The concrete is made from the following raw materials in parts by weight: 80-100 parts cement, 260-320 parts crushed stone, 220-250 parts sand, 35-50 parts fly ash, 25-35 parts silica fume, 10-15 parts zeolite powder, 8-12 parts steel fiber, 12-17 parts limestone, 1.5-3 parts sodium polyacrylate, 10-15 parts modified fiber, 3.5-5.5 parts functional additives, 2.5-6 parts water-reducing agent, 1-1.5 parts defoamer, 0.7-1.2 parts thickener, and 80-110 parts water.
3. The 3D-printed FRP profile self-compacting fiber reinforced concrete beam structure according to claim 2, characterized in that, The method for preparing the modified fiber includes the following steps: Step 1: Place the cleaned polypropylene fiber into a light-transmitting reactor, and sequentially add xylene (8-12 times the mass of the polypropylene fiber), dehydrated malic anhydride (3-8 times the mass of the polypropylene fiber), and benzoylbenzene (0.2-0.3 times the mass of the polypropylene fiber). Mix and stir evenly, and let stand at 40-50℃ for 20-30 hours. Then, purge the oxygen from the light-transmitting reactor with nitrogen gas, seal the reactor, and react under ultraviolet light irradiation for 5-8 hours. After the reaction is complete, filter out the polypropylene fiber, wash it with acetone, and then transfer it to a vacuum drying oven to dry to constant weight. Store the obtained primary modified polypropylene fiber for later use. Step 2: Immerse the primary modified polypropylene fiber in anhydrous ethanol at a solid-liquid ratio of 0.05–0.1 g / mL. Then, add 0.5–0.8 times the mass of the primary modified polypropylene fiber of 1-(3-dimethylaminopropyl)-3-ethylcarboimide and 6–12 times the mass of diethylenetriamine to the resulting mixture. After mixing and stirring evenly, reflux for 5–8 hours. After the reaction is complete, filter the resulting product and wash it 2–3 times with acetone and distilled water, respectively. Dry it to constant weight. The result is called secondary modified polypropylene fiber. Store it for later use. Step 3: Disperse the secondary modified polypropylene fiber evenly in N,N-dimethylformamide at a solid-liquid ratio of 0.01-0.02 g / mL. Add 1,2-ethanedicarboxylic acid (5-10 times the mass of the secondary modified polypropylene fiber) and 1-(3-dimethylaminopropyl)-3-ethylcarboimide (0.3-0.6 times the mass of the secondary modified polypropylene fiber) in sequence. Mix and stir until the 1,2-ethanedicarboxylic acid is completely dissolved. Then heat the resulting mixture to 90-100℃ and keep it at this temperature for 5-8 hours. After the reaction is complete, separate the reaction product into solid and liquid components. Wash the obtained solid filter material with acetone and distilled water 2-3 times and dry it to constant weight. The final product is the modified fiber.
4. A 3D-printed FRP profile self-compacting fiber reinforced concrete beam structure according to claim 2, characterized in that, The preparation method of the functional additive is as follows: I. Mix anhydrous calcium sulfate and aminoformaldehyde evenly at a weight ratio of 5-8:
1. Then add 20-30% by weight of silica sol to the resulting first mixture and stir evenly. Then add 10-25 times the weight of deionized water to the resulting second mixture and mechanically disperse evenly. Adjust the pH to 5.8-7.
3. Then introduce nitrogen gas into the resulting reaction system and keep it at 25-35°C for 3-5 hours. After the reaction is complete, let it cool naturally to room temperature. Store the resulting product components for later use. II. Add 4-8% sodium alginate by mass to the product component obtained in step I, mix and stir evenly, and keep it at 45-55℃ for 4-7 hours. After the reaction is completed, cool it naturally to room temperature, and then freeze-dry it for 20-30 hours to obtain the functional additive.
5. A 3D-printed FRP profile self-compacting fiber-reinforced concrete beam structure according to claim 2, characterized in that: The water-reducing agent is selected from any one of polycarboxylate water-reducing agents, naphthalene-based water-reducing agents, and sodium gluconate water-reducing agents.
6. A 3D-printed FRP profile self-compacting fiber reinforced concrete beam structure according to claim 2, characterized in that: The defoamer is selected from either polyoxyethylene polyoxypropylene amine ether or polyoxypropylene glycerol ether.
7. A 3D-printed FRP profile self-compacting fiber reinforced concrete beam structure according to claim 2, characterized in that: The thickener is selected from any one of polyacrylamide, cellulose ether, and polyvinyl alcohol.
8. A 3D-printed FRP profile self-compacting fiber reinforced concrete beam structure according to claim 3, characterized in that, The cleaning process for the polypropylene fiber is as follows: Soak the polypropylene fiber in acetone for 5 to 8 hours at a dosage ratio of 0.03 to 0.08 g / mL; then take it out, wash it with distilled water, and transfer it to a vacuum drying oven for drying. After drying, the cleaning process for the polypropylene fiber is completed.
9. A 3D-printed FRP profile self-compacting fiber-reinforced concrete beam structure according to claim 2, characterized in that: The prefabricated FRP profiles and FRP ribs are made of any one of basalt fiber, glass fiber, or carbon fiber.