Steel fiber reinforced geopolymer concrete material for 3D printing and preparation method thereof
By optimizing the multi-factor coupled control of steel fiber content and slurry rheological properties, the problem of insufficient interlayer bond strength of geopolymer concrete in 3D printing was solved, and the compressive and flexural properties were improved, meeting the requirements for use of 3D printed structural components.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI UNIV OF TECH
- Filing Date
- 2026-02-09
- Publication Date
- 2026-05-12
AI Technical Summary
In 3D printing, the interlayer bond strength of geopolymer concrete is insufficient and the existing steel fiber reinforcement effect is poor, resulting in the inability of its compressive and flexural strength to meet the requirements of structural components.
By using a specific ratio of slag, fly ash, quartz sand, solid alkali activator and steel fiber, and through multi-factor coupling control, the steel fiber content and slurry rheological properties are optimized to form a suitable steel fiber reinforced geopolymer concrete material, which is combined with the requirements of 3D printing process.
It significantly improves the compressive and flexural strength of geopolymer concrete, enhances the toughness and extrudability of the material, and meets the needs of high-performance 3D printed structural components.
Smart Images
Figure CN122010470A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of geopolymer concrete material technology, and particularly relates to a steel fiber reinforced geopolymer concrete material for 3D printing and its preparation method. Background Technology
[0002] 3D-printed concrete technology enables formwork-free construction by stacking materials layer by layer, demonstrating great potential in shaping complex geometries and improving construction efficiency. However, the widespread application of this technology is still limited by material properties, particularly the high carbon emissions associated with traditional silicate cement (OPC) as the primary binder. Statistics show that producing one ton of OPC emits approximately 500 to 600 kilograms of carbon dioxide, accounting for about 8% of global carbon emissions from its production process. To address this challenge, geopolymer concrete is considered a promising sustainable alternative. Geopolymers primarily use industrial solid wastes rich in silicon and aluminum, such as fly ash and granulated blast furnace slag, as precursors. They are formed through an alkali-activated reaction, reducing carbon dioxide emissions by up to 80% during production and possessing excellent properties such as early strength, high-temperature resistance, and corrosion resistance.
[0003] Despite the significant advantages of geopolymers in terms of environmental friendliness and some durability, their inherent brittleness severely limits their application in 3D printing, especially in structural components. Similar to traditional concrete, the tensile strength of geopolymers is typically only about one-tenth of their compressive strength, and even tiny cracks can easily lead to brittle failure. This problem is further amplified in the 3D printing process: the interlayer interfaces formed by layer-by-layer printing are weak points in the structure, and insufficient interlayer bond strength can easily lead to delamination under stress; at the same time, the precise constraints on the material's rheological properties and setting time during the printing process also increase the difficulty of material design.
[0004] Currently, fiber incorporation is a common method to improve the brittleness and crack resistance of concrete. Among them, steel fibers, due to their high elastic modulus, high strength, and excellent deformation resistance, are widely used in geopolymer 3D printing materials. However, in existing technologies, the incorporation effect of steel fibers is not ideal, failing to effectively improve the brittleness of geopolymers. The improvement in compressive strength, flexural strength, and toughness is limited, still unable to meet the actual stress requirements of 3D printed structural components, thus restricting the further application of geopolymer concrete in the field of 3D printing. Summary of the Invention
[0005] To address the issues of insufficient interlayer bond strength in geopolymer concrete 3D printing and the poor performance of existing steel fiber reinforcement, which prevents its compressive and flexural strength from meeting the requirements of 3D printed structural components, this invention provides a steel fiber reinforced geopolymer concrete material for 3D printing and its preparation method.
[0006] The technical solution of the present invention:
[0007] A steel fiber reinforced polymer concrete material for 3D printing comprises the following components in parts by weight: 2000 parts slag, 2000 parts fly ash, 6000 parts quartz sand, 360 parts solid alkali activator, 1320 parts water, 40 parts barium chloride, and 203-609 parts steel fiber.
[0008] Furthermore, the steel fibers have a diameter of 0.2 mm, a length of 6 mm, and a density of 7.85 g / cm³. 3 The elastic modulus is 210 GPa and the ultimate tensile strength is 3000 MPa.
[0009] Furthermore, the solid alkali activator is sodium silicate.
[0010] A method for preparing steel fiber reinforced geopolymer concrete material for 3D printing involves dry mixing slag and fly ash, then adding a solid alkali activator for secondary mixing to ensure uniform powder distribution; adding water to the resulting mixed powder, first stirring at low speed and then at high speed to obtain a uniform slurry, then adding steel fibers and continuing high-speed stirring to obtain foundation soil concrete slurry.
[0011] Furthermore, the stirring speed for the dry mixing process is 150 r / min and the stirring time is 2 min; the stirring speed for the secondary mixing process is 150 r / min and the stirring time is 3 min.
[0012] Furthermore, the low-speed stirring speed is 200 r / min, and the stirring time is 3 min.
[0013] Furthermore, the high-speed stirring speed is 500 r / min, the stirring time before adding steel fibers is 4 min, and the stirring time after adding steel fibers is 1 min.
[0014] Furthermore, the dynamic yield stress of the slurry is 581 Pa, the plastic viscosity is 51 Pa·s, the fluidity is 185 mm, and the setting time is 170 min.
[0015] The beneficial effects of this invention are:
[0016] This invention, based on a systematic study of multi-factor coupled regulation, overcomes the limitations of single-variable experiments by globally and synergistically optimizing steel fiber content, geopolymer slurry composition, and rheological properties, ultimately establishing the optimal relationship between fiber content and slurry rheological properties. Experiments show that, under the specified mix proportions, even with a steel fiber content of 1.5%, the slurry maintains suitable fluidity and yield stress, exhibiting good extrudability and shape retention, and can print regular, unbroken continuous lines.
[0017] Meanwhile, the addition of steel fibers comprehensively improves the mechanical properties of the material: compressive strength increases systematically with increasing fiber content, and the fibers act as micro-reinforcing materials to constrain the propagation of compressive cracks, enhancing load-bearing capacity and ductility; flexural strength and toughness are also significantly improved, and the fiber bridging effect effectively delays the initiation and propagation of cracks under bending loads. This invention successfully combines the requirements of 3D printing technology with the demand for high performance, laying a solid foundation for the preparation of high-performance, high-reliability 3D-printed geopolymer concrete structural components. Attached Figure Description
[0018] Figure 1 This is a comparison chart of the compressive strength of specimens from Examples 1-3 and Comparative Examples 1-4 after 28 days of curing;
[0019] Figure 2 This is a comparison of the flexural strength of specimens from Examples 1-3 and Comparative Examples 1-4 after 28 days of curing;
[0020] Figure 3 This is a comparison chart of the extrusion width of the 3D printing slurry in Examples 1-3 and Comparative Examples 1-4;
[0021] Figure 4 The image shows a scanning electron microscope image of the 3D-printed steel fiber reinforced geopolymer concrete obtained in Example 1.
[0022] Figure 5 The image shows a scanning electron microscope image of the 3D-printed steel fiber reinforced geopolymer concrete obtained in Example 2.
[0023] Figure 6 This is a scanning electron micrograph of the 3D-printed steel fiber reinforced geopolymer concrete obtained in Example 3. Detailed Implementation
[0024] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, the process equipment or apparatus not specifically specified are all conventional equipment or apparatus in the art. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available; unless otherwise specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.
[0025] Example 1
[0026] This embodiment provides a steel fiber reinforced geopolymer concrete material for 3D printing, comprising the following components in parts by weight:
[0027] 2000 parts slag, 2000 parts fly ash, 6000 parts quartz sand, 360 parts sodium silicate, 1320 parts water, 40 parts barium chloride, and 203 parts steel fiber.
[0028] The preparation method of steel fiber reinforced geopolymer concrete material in this embodiment is as follows:
[0029] Slag and fly ash were placed in a planetary mixer and dry-mixed at 150 rpm for 2 minutes. Then, sodium silicate, a solid alkali activator, was added for a second mixing of 3 minutes to ensure uniform powder distribution. Water was poured into the mixer hopper according to the preset water-cement ratio. Low-speed mixing was started at 200 rpm for 3 minutes, followed by high-speed mixing at 500 rpm for 4 minutes to form a homogeneous slurry. Steel fibers were then added, and high-speed mixing continued for 1 minute to obtain the geopolymer concrete slurry.
[0030] The dynamic yield stress of the homogeneous slurry obtained in this embodiment is 581 Pa, the plastic viscosity is 51 Pa·s, the fluidity is 185 mm, and the setting time is 170 min.
[0031] Using the geopolymer concrete slurry prepared in this embodiment as raw material, a desktop 3D printer was used with a precision stepper motor to control the extrusion process. The printing speed was 50 mm / s, the printer nozzle diameter was 20 mm, the printing thickness was 10 mm, and the printing path adopted a unidirectional printing path to ensure that the internal structure of the specimen was uniform and without obvious pores.
[0032] Immediately after printing, the specimens should be placed in a constant temperature and humidity curing chamber. The curing environment should be 20±2℃ and 95±5% relative humidity for 28 days. During the curing period, the specimens should be placed horizontally to avoid pressure or impact.
[0033] Example 2
[0034] This embodiment provides a steel fiber reinforced geopolymer concrete material for 3D printing, comprising the following components in parts by weight:
[0035] 2000 parts slag, 2000 parts fly ash, 6000 parts quartz sand, 360 parts sodium silicate, 1320 parts water, 40 parts barium chloride, and 406 parts steel fiber.
[0036] The preparation method of steel fiber reinforced geopolymer concrete material in this embodiment is as follows:
[0037] Slag and fly ash were placed in a planetary mixer and dry-mixed at 150 rpm for 2 minutes. Then, sodium silicate, a solid alkali activator, was added for a second mixing of 3 minutes to ensure uniform powder distribution. Water was poured into the mixer hopper according to the preset water-cement ratio. Low-speed mixing was started at 200 rpm for 3 minutes, followed by high-speed mixing at 500 rpm for 4 minutes to form a homogeneous slurry. Steel fibers were then added, and high-speed mixing continued for 1 minute to obtain the geopolymer concrete slurry.
[0038] The dynamic yield stress of the homogeneous slurry obtained in this embodiment is 581 Pa, the plastic viscosity is 51 Pa·s, the fluidity is 185 mm, and the setting time is 170 min.
[0039] Using the geopolymer concrete slurry prepared in this embodiment as raw material, a desktop 3D printer was used with a precision stepper motor to control the extrusion process. The printing speed was 50 mm / s, the printer nozzle diameter was 20 mm, the printing thickness was 10 mm, and the printing path adopted a unidirectional printing path to ensure that the internal structure of the specimen was uniform and without obvious pores.
[0040] Immediately after printing, the specimens should be placed in a constant temperature and humidity curing chamber. The curing environment should be 20±2℃ and 95±5% relative humidity for 28 days. During the curing period, the specimens should be placed horizontally to avoid pressure or impact.
[0041] Example 3
[0042] This embodiment provides a steel fiber reinforced geopolymer concrete material for 3D printing, comprising the following components in parts by weight:
[0043] 2000 parts slag, 2000 parts fly ash, 6000 parts quartz sand, 360 parts sodium silicate, 1320 parts water, 40 parts barium chloride, and 609 parts steel fiber.
[0044] The preparation method of steel fiber reinforced geopolymer concrete material in this embodiment is as follows:
[0045] Slag and fly ash were placed in a planetary mixer and dry-mixed at 150 rpm for 2 minutes. Then, sodium silicate, a solid alkali activator, was added for a second mixing of 3 minutes to ensure uniform powder distribution. Water was poured into the mixer hopper according to the preset water-cement ratio. Low-speed mixing was started at 200 rpm for 3 minutes, followed by high-speed mixing at 500 rpm for 4 minutes to form a homogeneous slurry. Steel fibers were then added, and high-speed mixing continued for 1 minute to obtain the geopolymer concrete slurry.
[0046] The dynamic yield stress of the homogeneous slurry obtained in this embodiment is 581 Pa, the plastic viscosity is 51 Pa·s, the fluidity is 185 mm, and the setting time is 170 min.
[0047] Using the geopolymer concrete slurry prepared in this embodiment as raw material, a desktop 3D printer was used with a precision stepper motor to control the extrusion process. The printing speed was 50 mm / s, the printer nozzle diameter was 20 mm, the printing thickness was 10 mm, and the printing path adopted a unidirectional printing path to ensure that the internal structure of the specimen was uniform and without obvious pores.
[0048] Immediately after printing, the specimens should be placed in a constant temperature and humidity curing chamber. The curing environment should be 20±2℃ and 95±5% relative humidity for 28 days. During the curing period, the specimens should be placed horizontally to avoid pressure or impact.
[0049] Comparative Example 1
[0050] This comparative example provides a geopolymer concrete material for 3D printing, comprising the following components in parts by weight:
[0051] 2000 parts slag, 2000 parts fly ash, 6000 parts quartz sand, 360 parts sodium silicate, 1320 parts water and 40 parts barium chloride.
[0052] The preparation method of this comparative example of polymer-concrete material is as follows:
[0053] Slag and fly ash are placed in a planetary mixer and dry-mixed at 150 rpm for 2 minutes. Then, sodium silicate, a solid alkali activator, is added for secondary mixing for 3 minutes to ensure uniform powder distribution. Water is poured into the mixer hopper according to the preset water-cement ratio, and the mixer is started at low speed (200 rpm) for 3 minutes, then switched to high speed (500 rpm) for 4 minutes to form a geopolymer concrete slurry.
[0054] The dynamic yield stress of the geopolymer concrete slurry obtained in this comparative example is 581 Pa, the plastic viscosity is 51 Pa·s, the fluidity is 185 mm, and the setting time is 170 min.
[0055] Using the geopolymer concrete slurry prepared in this comparative example as raw material, a desktop 3D printer was used with a precision stepper motor to control the extrusion process. The printing speed was 50 mm / s, the printer nozzle diameter was 20 mm, the printing thickness was 10 mm, and the printing path adopted a unidirectional printing path to ensure that the internal structure of the specimen was uniform and without obvious pores.
[0056] Immediately after printing, the specimens should be placed in a constant temperature and humidity curing chamber. The curing environment should be 20±2℃ and 95±5% relative humidity for 28 days. During the curing period, the specimens should be placed horizontally to avoid pressure or impact.
[0057] Comparative Example 2
[0058] This comparative example provides a geopolymer concrete material for 3D printing, comprising the following components in parts by weight:
[0059] 1600 parts slag, 2400 parts fly ash, 6000 parts quartz sand, 360 parts sodium silicate, 1320 parts water and 40 parts barium chloride.
[0060] The preparation method of this comparative example of polymer-concrete material is as follows:
[0061] Slag and fly ash are placed in a planetary mixer and dry-mixed at 150 rpm for 2 minutes. Then, sodium silicate, a solid alkali activator, is added for secondary mixing for 3 minutes to ensure uniform powder distribution. Water is poured into the mixer hopper according to the preset water-cement ratio, and the mixer is started at low speed (200 rpm) for 3 minutes, then switched to high speed (500 rpm) for 4 minutes to form a geopolymer concrete slurry.
[0062] The dynamic yield stress of the geopolymer concrete slurry obtained in this comparative example is 415 Pa, the plastic viscosity is 44 Pa·s, the fluidity is 189 mm, and the setting time is 175 min.
[0063] Using the geopolymer concrete slurry prepared in this comparative example as raw material, a desktop 3D printer was used with a precision stepper motor to control the extrusion process. The printing speed was 50 mm / s, the printer nozzle diameter was 20 mm, the printing thickness was 10 mm, and the printing path adopted a unidirectional printing path to ensure that the internal structure of the specimen was uniform and without obvious pores.
[0064] Immediately after printing, the specimens should be placed in a constant temperature and humidity curing chamber. The curing environment should be 20±2℃ and 95±5% relative humidity for 28 days. During the curing period, the specimens should be placed horizontally to avoid pressure or impact.
[0065] Comparative Example 3
[0066] This comparative example provides a geopolymer concrete material for 3D printing, comprising the following components in parts by weight:
[0067] 1200 parts slag, 2800 parts fly ash, 6000 parts quartz sand, 360 parts sodium silicate, 1320 parts water and 40 parts barium chloride.
[0068] The preparation method of this comparative example of polymer-concrete material is as follows:
[0069] Slag and fly ash are placed in a planetary mixer and dry-mixed at 150 rpm for 2 minutes. Then, sodium silicate, a solid alkali activator, is added for secondary mixing for 3 minutes to ensure uniform powder distribution. Water is poured into the mixer hopper according to the preset water-cement ratio, and the mixer is started at low speed (200 rpm) for 3 minutes, then switched to high speed (500 rpm) for 4 minutes to form a geopolymer concrete slurry.
[0070] The dynamic yield stress of the geopolymer concrete slurry obtained in this comparative example is 446 Pa, the plastic viscosity is 39 Pa·s, the fluidity is 193 mm, and the setting time is 185 min.
[0071] Using the geopolymer concrete slurry prepared in this comparative example as raw material, a desktop 3D printer was used with a precision stepper motor to control the extrusion process. The printing speed was 50 mm / s, the printer nozzle diameter was 20 mm, the printing thickness was 10 mm, and the printing path adopted a unidirectional printing path to ensure that the internal structure of the specimen was uniform and without obvious pores.
[0072] Immediately after printing, the specimens should be placed in a constant temperature and humidity curing chamber. The curing environment should be 20±2℃ and 95±5% relative humidity for 28 days. During the curing period, the specimens should be placed horizontally to avoid pressure or impact.
[0073] Comparative Example 4
[0074] This comparative example provides a geopolymer concrete material for 3D printing, comprising the following components in parts by weight:
[0075] 800 parts slag, 3200 parts fly ash, 6000 parts quartz sand, 360 parts sodium silicate, 1320 parts water and 40 parts barium chloride.
[0076] The preparation method of this comparative example of polymer-concrete material is as follows:
[0077] Slag and fly ash are placed in a planetary mixer and dry-mixed at 150 rpm for 2 minutes. Then, sodium silicate, a solid alkali activator, is added for secondary mixing for 3 minutes to ensure uniform powder distribution. Water is poured into the mixer hopper according to the preset water-cement ratio, and the mixer is started at low speed (200 rpm) for 3 minutes, then switched to high speed (500 rpm) for 4 minutes to form a geopolymer concrete slurry.
[0078] The dynamic yield stress of the geopolymer concrete slurry obtained in this comparative example is 390 Pa, the plastic viscosity is 37 Pa·s, the fluidity is 197 mm, and the setting time is 200 min.
[0079] Using the geopolymer concrete slurry prepared in this comparative example as raw material, a desktop 3D printer was used with a precision stepper motor to control the extrusion process. The printing speed was 50 mm / s, the printer nozzle diameter was 20 mm, the printing thickness was 10 mm, and the printing path adopted a unidirectional printing path to ensure that the internal structure of the specimen was uniform and without obvious pores.
[0080] Immediately after printing, the specimens should be placed in a constant temperature and humidity curing chamber. The curing environment should be 20±2℃ and 95±5% relative humidity for 28 days. During the curing period, the specimens should be placed horizontally to avoid pressure or impact.
[0081] After curing the specimens of Examples 1-3 and Comparative Examples 1-4 for 28 days, the 3D printed specimens were cut into standard test specimens using a diamond cutter. The compressive strength test (cubic specimen): 40mm×40mm×40mm, and the flexural strength test (prism specimen): 40mm×40mm×160mm.
[0082] Compressive strength test: Performed according to ASTM C109 standard using a WAW-300 universal servo compression testing machine with a loading speed of 0.5 MPa / s. The average value of three specimens was taken as the compressive strength result. Flexural strength test: Also performed according to ASTM C109 standard using a YAW-800 electronic universal testing machine. A three-point bending device with a span of 100 mm was used, with a displacement control rate of 1 mm / min. The flexural strength values were calculated, and the results are shown in Table 1. Figure 1 , Figure 2 As shown.
[0083] Table 1
[0084]
[0085] This invention, based on a systematic study of multi-factor coupled regulation, overcomes the limitations of single-variable experiments by globally and synergistically optimizing the steel fiber content, geopolymer slurry composition, and rheological properties, ultimately establishing the compatibility relationship between fiber content and slurry rheological properties. As shown in Table 1, the mechanical properties of the example series are comprehensively superior to the comparative examples: Example 3 achieved a compressive strength of 79.65 MPa, an increase of approximately 44.3% compared to Comparative Example 4; its flexural strength reached 12.75 MPa, an increase of approximately 102.4% compared to Comparative Example 4. Even compared to Comparative Example 1, which had relatively better performance, the compressive strength still increased by approximately 18.7%, and the flexural strength increased by approximately 37.1%, achieving balanced and continuous performance growth. The increase in flexural strength is significantly higher than that in compressive strength, indicating that the synergistic optimization precisely controlled the bridging effect of the steel fibers, resulting in a significant effect in suppressing the propagation of bending cracks. This also demonstrates that this invention, through systematic multi-factor coupled regulation, successfully achieved a dual breakthrough in 3D printing suitability and material mechanical properties, laying a solid foundation for the preparation of high-performance 3D-printed geopolymer concrete structural components.
[0086] Figure 3 The figures show a comparison of the extrusion widths of 3D printing slurries with different formulations in Examples 1-3 and Comparative Examples 1-4. The results show that the extrusion width of the slurries in the comparative examples is generally higher than that in the examples, and it shows an increasing trend with the adjustment of the formulation. The extrusion width of the slurries in the examples is narrower and fluctuates less, indicating that their rheological properties, including thixotropy and yield stress, are better, and they can achieve more stable and finer extrusion molding.
[0087] Figures 4-6 The images show the microstructure of the 3D-printed steel fiber reinforced geopolymer concrete obtained in Examples 1-3, such as... Figures 4-6 As shown, under the activation of sodium silicate activator, fly ash and slag in the cementitious material participate in the reaction, forming a rich hydration product system, including a large number of amorphous and gel-like solidified phases. Simultaneously, some incompletely reacted fly ash particles are visible distributed within the matrix. Influenced by the hydrophilic properties of the steel fiber surface and the ion diffusion behavior in the interfacial region, the hydration process in the fiber-matrix interface transition zone is more significant, leading to localized Ca2+ hydration. 2+ As the concentration decreases, a region with a relatively low degree of reaction is formed. The microstructural characteristics of this region may weaken the bond strength between the fiber and the matrix.
[0088] Nevertheless, steel fibers, with their high elastic modulus and outstanding crack-crossing and bridging capabilities, still play a crucial role in the macroscopic mechanical behavior of composite materials. The aforementioned mutually restrictive mechanisms help explain the influence of steel fiber content and aspect ratio variations on the material's mechanical properties: the hydration products generated at the interface and the resulting mechanical anchoring effect help improve the interfacial bonding performance; while the presence of weak areas at the interface may have negative impacts. Overall, the reinforcing effect of fibers is dominant, macroscopically manifested as a general increase in material strength. This microscopic mechanism is consistent with experimental observations, namely, the addition of steel fibers significantly improves the tensile properties of concrete, mainly due to the effective inhibition and bridging effect of fibers on crack propagation during tension.
Claims
1. A steel fiber reinforced geopolymer concrete material for 3D printing, characterized in that, The components include the following parts by weight: 2000 parts slag, 2000 parts fly ash, 6000 parts quartz sand, 360 parts solid alkali activator, 1320 parts water, 40 parts barium chloride, and 203-609 parts steel fiber.
2. The steel fiber reinforced geopolymer concrete material for 3D printing according to claim 1, characterized in that, The steel fibers have a diameter of 0.2 mm, a length of 6 mm, and a density of 7.85 g / cm³. 3 The elastic modulus is 210 GPa and the ultimate tensile strength is 3000 MPa.
3. The steel fiber reinforced geopolymer concrete material for 3D printing according to claim 2, characterized in that, The solid alkali activator is sodium silicate.
4. A method for preparing a steel fiber reinforced geopolymer concrete material for 3D printing as described in any one of 1-3, characterized in that, After the slag and fly ash are dry-mixed evenly, a solid alkali activator is added for secondary mixing to ensure uniform powder distribution. Water is added to the resulting mixed powder, and the mixture is first stirred at low speed and then at high speed to obtain a uniform slurry. Steel fibers are added and the mixture is stirred at high speed to obtain the foundation soil concrete slurry.
5. The method for preparing steel fiber reinforced geopolymer concrete material for 3D printing according to claim 4, characterized in that, The stirring speed for the dry mixing process is 150 r / min and the stirring time is 2 min; the stirring speed for the secondary mixing process is 150 r / min and the stirring time is 3 min.
6. The method for preparing steel fiber reinforced geopolymer concrete material for 3D printing according to claim 5, characterized in that, The low-speed stirring speed is 200 r / min, and the stirring time is 3 min.
7. The method for preparing steel fiber reinforced geopolymer concrete material for 3D printing according to claim 6, characterized in that, The high-speed mixer operates at a speed of 500 r / min, with a mixing time of 4 min before adding steel fibers and a mixing time of 1 min after adding steel fibers.
8. The method for preparing steel fiber reinforced geopolymer concrete material for 3D printing according to claim 7, characterized in that, The slurry has a dynamic yield stress of 581 Pa, a plastic viscosity of 51 Pa·s, a fluidity of 185 mm, and a setting time of 170 min.