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CN-121976668-A - Support reinforcement integrated construction method for 3D printed concrete suspension structure

CN121976668ACN 121976668 ACN121976668 ACN 121976668ACN-121976668-A

Abstract

The invention relates to a support reinforcement integrated construction method for a 3D printed concrete suspension structure, which comprises the steps of S1, calculating the critical overturning layer number according to construction requirements, calculating the minimum layer number and the anchoring length of steel wire grids required by the maximum suspension section according to the critical overturning layer number, constructing a target suspension structure, S2, converting a three-dimensional model of the target suspension structure into a G-code containing a printing path, driving 3D printing equipment to print layer by layer, iteratively executing S3 if the next layer is the suspension layer, suspending after finishing printing of the current layer of concrete, paving a layer of steel wire grids on the surface of the suspension layer, S4, continuing printing a concrete layer of the next suspension area above the steel wire grids, enabling the steel wire grids to be clamped between the two layers, S5, judging whether the current printing height is smaller than the critical overturning layer number, if not, ending printing, and otherwise returning to S2. The invention realizes the function integration of construction support and structural reinforcement, and improves the printing efficiency, the material utilization rate and the structural performance.

Inventors

  • DING TAO
  • CAO XIAOYING

Assignees

  • 同济大学

Dates

Publication Date
20260505
Application Date
20260331

Claims (10)

  1. 1. The integrated construction method for the support reinforcement of the 3D printed concrete suspension structure is characterized by comprising the following steps of: S1, calculating a critical overturning layer number based on construction requirements, and calculating a minimum layer number of steel wire grids and an anchoring length thereof required in a maximum suspension section based on the critical overturning layer number to construct a target suspension structure; s2, converting a digital three-dimensional model of the target overhang structure into a G-code, wherein the G-code comprises a printing path; Driving the 3D printing equipment to print the concrete overhang structure layer by layer along the printing path, and if the next layer is an overhang layer, iteratively executing the following steps: S3, suspending concrete printing after finishing the printing of the current layer of concrete, and paving a layer of steel wire grids on the surface of the current concrete layer; s4, continuously printing a concrete layer of a next overhanging region above the steel wire grid until the current steel wire grid is positioned between the current concrete layer and the concrete layer of the next overhanging region; s5, judging whether the current printing height is smaller than the critical overturning layer number, if not, finishing printing to obtain a final concrete suspension structure, otherwise, returning to the step S2.
  2. 2. The method for integrally constructing the support reinforcement for the 3D printed concrete suspension structure according to claim 1, wherein the method for calculating the critical overturning layer number is as follows: Based on the construction requirement, obtaining the side section width, the concrete layer height and the overhang angle, and calculating the critical overturning layer number as follows: ; Wherein, the Representing a side cross-sectional width; Representing the overhang angle; Indicating the concrete layer height.
  3. 3. The method of claim 1, wherein the wire mesh comprises a first section and a second section, the first section is anchored to the current concrete layer, and the second section is located between the current concrete layer and the next concrete layer in the overhanging region.
  4. 4. The method for integrally constructing the support reinforcement for the 3D printed concrete suspension structure according to claim 1, wherein the mesh size and the wire diameter of the wire mesh are determined according to suspension span, concrete rheological property and final structure stress requirements.
  5. 5. The method for integrally constructing the support reinforcement for the 3D printed concrete suspension structure according to claim 1, wherein the method for calculating the minimum number of layers of steel wire grids and the anchoring length thereof required in the maximum suspension section is as follows: calculating the number of layers of the minimum anchoring net sheet required in the maximum overhanging section by combining the minimum reinforcement ratio condition with the section reinforcement ratio formula : ; Wherein, the Representing the standard value of the tensile strength of the concrete; representing the steel wire yield strength; Indicating the number of critical flip layers, , Representing a side cross-sectional width; d is the mesh side length of the steel wire mesh; representing the diameter of a single steel wire; calculating the anchoring length based on the minimum number of anchoring net layers required in the maximum suspension section The expression is: ; Wherein, the Representing the length of each layer of wire mesh.
  6. 6. A support reinforcement integration construction method for a 3D printed concrete suspension structure according to claim 1, wherein the concrete suspension structure comprises a first type of structure having a suspension center of gravity located within the non-suspension region and a second type of structure having a suspension center of gravity located outside the non-suspension region.
  7. 7. The method for integrally constructing a 3D printed concrete suspension structure supporting reinforcement according to claim 6, wherein for said first type of structure, S3 is performed after said wire mesh is laid, and for said second type of structure, S3 is performed after said current concrete layer is hardened.
  8. 8. The integrated construction method for the support reinforcement of the 3D printed concrete suspension structure according to claim 1, wherein the concrete suspension structure comprises a plurality of layers of steel wire grids which are equidistantly arranged in the direction perpendicular to the concrete layer.
  9. 9. The integrated construction method for supporting reinforcement of 3D printed concrete overhang structure according to any one of claims 8, wherein the spacing between two adjacent steel wire grids in the direction perpendicular to the concrete layer is matched with the 3D printed layer height or is an integer multiple of the 3D printed layer height.
  10. 10. A support reinforcement integrated construction method for a 3D printed concrete suspension structure according to claim 1, wherein a fiber material is doped to the concrete of each concrete layer.

Description

Support reinforcement integrated construction method for 3D printed concrete suspension structure Technical Field The invention relates to the technical field of intelligent construction, in particular to a support reinforcement integrated construction method for a 3D printed concrete suspension structure. Background The building 3D printing technology has been rapidly developed in recent years due to the advantages of automation, template-free, high design freedom, labor saving and the like. However, printing a structure with overhang features, i.e. when the subsequent printed layer is horizontally overhanging relative to the printed layer, because the tensile strength of the concrete material is extremely low before solidification and the concrete material cannot bear dead weight, the concrete material is extremely easy to flow, deform and collapse, which is one of the key problems restricting the application of the technology, currently, the main method for solving the problem of 3D printing overhang is that 1) a soluble or breakable temporary supporting material is used, additional procedures are needed for removal after the printing is finished, the material waste and the process are complicated, 2) a printing path and a material formula are optimized to be extremely fast coagulated for 'hanging' printing, but the requirement on the material performance is limited, the printing speed is difficult to be used for large-span overhang, and 3) an independent permanent support or template is pre-installed, which is contrary to the mould-free advantage of 3D printing. In order to avoid the defects of the three methods, the Chinese patent application CN117432071A provides a 3D printing method for a rotating curved surface concrete structure based on a self-supporting angle of an overhang effect, the limiting self-supporting angle of the structure is determined through a test, and the rotating curved surface is segmented according to the limiting self-supporting angle, so that temporary support in the printing process is reduced or avoided to a certain extent, and an effective scheme is provided for printing the curved surface structure. However, the technical scheme mainly focuses on the problem of self-stabilization of the structure in the printing process, and is characterized in that the unsupported printing in the construction stage is realized through geometric segmentation, and the mechanical property guarantee of the structure in the use stage is ignored. Meanwhile, for a bearing structure, the safety requirement of the building structure cannot be met by only realizing the unsupported printing at the construction stage. The traditional cast-in-place concrete bears the tensile force through the built-in reinforcement cage, the 3D printing process is stacked layer by layer, the interlayer bonding force is weak, the whole tensile resistance and the crack resistance are lacked, so that the support-free printing can be realized, the sufficient tensile resistance, shearing resistance and crack resistance of the structure can be realized through reinforcement while the support-free printing is ensured, and the 3D printing method is a necessary means for realizing the 3D printing of the bearing structure. Thus, there is a need in the art for an integrated solution that enables the joint design of temporary support requirements for printing of overhanging structures with permanent reinforcement requirements for the structures. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a supporting reinforcement integrated construction method for a 3D printing concrete suspension structure, wherein a steel wire grid which is good in flexibility and capable of being rapidly paved is used as a medium, the steel wire grid is enabled to become a skeleton and a support bottom of unhardened concrete of a suspension part in the printing process and is enabled to bear a temporary supporting function, after the structure is hardened, the steel wire grid is enabled to become a reinforcing rib in the concrete body and is enabled to bear a permanent reinforcement function, so that two problems of supporting and reinforcing are solved simultaneously, the material utilization rate is maximized, and in addition, the critical overturning layer number and the anchoring length of the steel wire grid are preferentially calculated before printing, so that the whole engineering can be guaranteed under a working condition with enough safety. The aim of the invention can be achieved by the following technical scheme: According to a first aspect of the present invention, there is provided a support-reinforcement integrated construction method for a 3D printed concrete suspension structure, the method comprising: S1, calculating a critical overturning layer number based on construction requirements, and calculating a minimum layer number of steel wire grids and an anchoring length thereof required in