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CN-122010470-A - Steel fiber reinforced geopolymer concrete material for 3D printing and preparation method thereof

CN122010470ACN 122010470 ACN122010470 ACN 122010470ACN-122010470-A

Abstract

The invention belongs to the technical field of geopolymer concrete materials, and particularly relates to a steel fiber reinforced geopolymer concrete material for 3D printing and a preparation method thereof. In order to solve the problems that the 3D printing interlayer bonding strength of the geopolymer concrete is insufficient and the compression resistance and the fracture resistance of the conventional steel fiber are not enough to meet the use requirement of a 3D printing structural member due to the poor reinforcing effect of the conventional steel fiber, the invention provides a steel fiber reinforced geopolymer concrete material for 3D printing, which comprises the following components of slag, fly ash, quartz sand, sodium silicate, water, barium chloride and steel fiber. The invention is based on systematic research of multi-factor coupling regulation, and through global cooperative optimization of the doping amount of the steel fiber, the components of the geopolymer slurry and the rheological property, even if the doping amount of the steel fiber reaches 1.5%, the slurry can still keep proper fluidity and yield stress, thereby realizing comprehensive improvement of compressive strength, flexural strength and toughness.

Inventors

  • PAN ZHU
  • ZHENG GONG
  • WANG LI

Assignees

  • 河北工业大学

Dates

Publication Date
20260512
Application Date
20260209

Claims (8)

  1. 1. The steel fiber reinforced geopolymer concrete material for 3D printing is characterized by comprising the following components, by mass, 2000 parts of slag, 2000 parts of fly ash, 6000 parts of quartz sand, 360 parts of solid alkali-exciting agent, 1320 parts of water, 40 parts of barium chloride and 203-609 parts of steel fiber.
  2. 2. The steel fiber reinforced polymer concrete material for 3D printing according to claim 1, wherein the steel fiber has a diameter of 0.2mm, a length of 6mm, a density of 7.85g/cm 3 , an elastic modulus of 210Gpa, and an ultimate tensile strength of 3000MPa.
  3. 3. A steel fibre reinforced geopolymer concrete material for 3D printing according to claim 2, wherein the solid alkali-activator is sodium silicate.
  4. 4. A preparation method of the steel fiber reinforced geopolymer concrete material for 3D printing is characterized by comprising the steps of mixing slag and fly ash uniformly, adding a solid alkali activator for secondary mixing to ensure uniform powder distribution, adding water into the obtained mixed powder, stirring at a low speed and then stirring at a high speed to obtain uniform slurry, adding steel fibers, and continuing stirring at a high speed to obtain the ground soil concrete slurry.
  5. 5. The method for preparing the steel fiber reinforced polymer concrete material for 3D printing according to claim 4, wherein the stirring speed of the dry mixing treatment is 150r/min, the stirring time is 2min, the stirring speed of the secondary mixing is 150r/min, and the stirring time is 3min.
  6. 6. The method for preparing a steel fiber reinforced geopolymer concrete material for 3D printing according to claim 5, wherein the stirring speed of the low-speed stirring is 200r/min and the stirring time is 3min.
  7. 7. The method for preparing a steel fiber reinforced geopolymer concrete material for 3D printing according to claim 6, wherein the stirring speed of the high-speed stirring is 500r/min, the stirring time before adding the steel fiber is 4min, and the stirring time after adding the steel fiber is 1min.
  8. 8. The method for preparing a steel fiber reinforced geopolymer concrete material for 3D printing according to claim 7, wherein the dynamic yield stress of the slurry is 581Pa, the plastic viscosity is 51 Pa-s, the fluidity is 185mm, and the setting time is 170min.

Description

Steel fiber reinforced geopolymer concrete material for 3D printing and preparation method thereof Technical Field The invention belongs to the technical field of geopolymer concrete materials, and particularly relates to a steel fiber reinforced geopolymer concrete material for 3D printing and a preparation method thereof. Background The 3D printing concrete technology realizes template-free construction by stacking materials layer by layer, and has great potential in the aspects of modeling complex geometric structures and improving construction efficiency. However, the widespread use of this technology is still limited by material properties, particularly the high carbon emissions problems associated with conventional Portland cement (OPC) as the primary cementitious material. It is counted that OPC produces about 500 to 600 kg of carbon dioxide per ton of production, and the carbon emissions during production account for about 8% of the total world. To address this challenge, geopolymer concrete is considered as a very promising sustainable alternative. The geopolymer is formed by using industrial solid wastes rich in silicon and aluminum, such as fly ash, granulated blast furnace slag and the like, as precursors through alkali-activated reaction, can reduce carbon dioxide emission by 80% in the production process, and has the excellent characteristics of early strength, high temperature resistance, corrosion resistance and the like. While geopolymers offer significant environmental and partial durability advantages, their inherent brittleness problems severely limit their use in 3D printing, particularly in structural members. Like conventional concrete, the tensile strength of geopolymers is usually only about one tenth of the compressive strength, and small cracks are extremely prone to brittle failure. The problem is further amplified in the 3D printing process, an interlayer interface formed by layer-by-layer printing is a structural weak link, interlayer peeling is easily caused when a member is stressed due to insufficient interlayer bonding strength, and meanwhile, the printing process is used for accurately restraining rheological property and setting time of materials, so that the difficulty of material design is increased. At present, the incorporation of fibers is a common means for improving the brittleness of concrete and improving the cracking resistance, wherein steel fibers are widely tried to be applied to geopolymer 3D printing materials due to the high elastic modulus, high strength and excellent deformation resistance. However, in the prior art, the doping effect of the steel fiber is poor, the brittleness defect of the geopolymer cannot be effectively improved, the improvement range of the compression resistance, the flexural strength and the toughness is limited, the practical stress application requirement of the 3D printing structural member cannot be met, and the further application of the geopolymer concrete in the 3D printing field is limited. Disclosure of Invention The invention provides a steel fiber reinforced geopolymer concrete material for 3D printing and a preparation method thereof, aiming at solving the problems that the compressive and fracture resistance performance of the geopolymer concrete cannot meet the use requirement of a 3D printing structural member due to insufficient bonding strength between 3D printing layers and poor reinforcing effect of the existing steel fiber. The technical scheme of the invention is as follows: The steel fiber reinforced geopolymer concrete material for 3D printing comprises the following components, by mass, 2000 parts of slag, 2000 parts of fly ash, 6000 parts of quartz sand, 360 parts of solid alkali-exciting agent, 1320 parts of water, 40 parts of barium chloride and 203-609 parts of steel fiber. Further, the steel fiber has a diameter of 0.2mm, a length of 6mm, a density of 7.85g/cm 3, an elastic modulus of 210GPa, and an ultimate tensile strength of 3000MPa. Further, the solid alkali activator is sodium silicate. A preparation method of a steel fiber reinforced geopolymer concrete material for 3D printing comprises the steps of adding solid alkali excitant into slag and fly ash after dry mixing uniformly to ensure uniform distribution of powder, adding water into the obtained mixed powder, stirring at a low speed and then stirring at a high speed to obtain uniform slurry, and adding steel fibers to continuously stir at a high speed to obtain the base soil concrete slurry. Further, the stirring speed of the dry mixing treatment is 150r/min, the stirring time is 2min, the stirring speed of the secondary mixing is 150r/min, and the stirring time is 3min. Further, the stirring speed of the low-speed stirring is 200r/min, and the stirring time is 3min. Further, the stirring speed of the high-speed stirring is 500r/min, the stirring time before adding the steel fiber is 4min, and the stirring time after adding the steel fiber is