3D Printed Concrete Horizontal Member Bottom Mesh Aperture
Solution Overview
Problem
Current concrete 3-D printing technologies are limited to printing vertical load-bearing members like walls and columns due to the initial setting time of concrete, and horizontal load-bearing members such as floors and beams cannot be in-situ support-free printed using traditional methods, as the concrete leaks through existing reinforcing mesh sheets.
Innovation Solution
A combined accessory for in-situ concrete 3-D printed horizontal load-bearing members, utilizing 3-D printed concrete with specific fine aggregate sizes and fluidity, paired with a reinforcing mesh or expanded metal bottom mesh, where the mesh aperture is optimized to retain the concrete, allowing for direct printing and subsequent layering without support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional bottom mold or prefabricated member assembling mode is used for horizontal load-bearing members, then the concrete can be supported during printing, but the method cannot achieve in-situ support-free printing and requires additional molds or prefabricated components
Solution Approach 1:
The patent extracts the support function from traditional bottom molds or prefabricated members and integrates it directly into the printed structure itself. The bottom mesh is embedded within the concrete layers, allowing the printed member to support its own weight and subsequent layers without external support structures, thus achieving support-free printing while reducing device complexity
Solution Approach 2:
The bottom mesh is pre-installed at the printing location before concrete deposition begins. This preliminary placement of the reinforcement mesh enables immediate support for the first layer of concrete, eliminating the need for temporary molds or prefabricated support members and enabling direct in-situ printing
2Strength
If existing reinforcing mesh sheet with 100-200 mm mesh size is used, then it works for vertical structures, but the concrete leaks through the meshes and cannot support horizontal load-bearing members
Solution Approach 1:
The patent changes the mesh aperture parameter from the conventional 100-200 mm size to a much smaller size range of 0.6-3.75 mm, which is specifically optimized to retain the 3-D printed concrete mixture while still allowing proper bonding and structural performance. This parameter adjustment enables the mesh to function effectively for horizontal load-bearing members
Solution Approach 2:
The patent applies different mesh specifications at different locations and for different structural requirements. The bottom mesh uses small aperture (0.6-3.75 mm) for concrete retention, while the upper reinforcing cage can use larger mesh sizes for structural reinforcement, optimizing both concrete retention and structural strength
3Strength
If the mesh aperture is made smaller to retain concrete, then concrete leakage is prevented, but the mesh becomes more complex and harder to handle
Solution Approach 1:
The patent creates a composite structure combining the bottom mesh with the 3-D printed concrete and upper reinforcing cage. The bottom mesh with small aperture works in conjunction with the concrete mixture and upper reinforcement to achieve both concrete retention and structural strength, distributing the functional requirements across multiple components rather than relying solely on mesh complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables support-free printing of horizontal load-bearing members by ensuring the concrete permeates and sets within the mesh, forming a cohesive structure that can bear weight, allowing for continuous layering and enhanced structural rigidity, with options for varying mesh shapes and reinforcing bar diameters based on span and structure type.
Implementation Method 1
the 3-D printed concrete permeates and sets within the mesh
Implementation Method 2
the concrete permeates through the meshes of the bottom mesh to wrap the bottom mesh
Implementation Method 3
the fluidity of the 3-D printed concrete is larger than or equal to 110 mm and smaller than or equal to 190 mm
Implementation Method 4
the bottom mesh is a reinforcing mesh or expanded metal, the diameter of the reinforcing bar is larger than or equal to 0.5 mm
Data Source
AI summary
This technology comprises a combined accessory of an in-situ concrete 3-D printed horizontal load-bearing member and a preparation method. The combined accessory includes 3-D printed concrete and a bottom mesh, the 3-D printed concrete contains fine aggregates having the particle size of 0.08 mm-4.75 mm, and the fluidity of the 3-D printed concrete is larger than or equal to 110 mm and smaller than or equal to 190 mm; the bottom mesh is a reinforcing mesh or expanded metal, the diameter of the reinforcing bar is larger than or equal to 0.5 mm, and the mesh aperture of the reinforcing mesh is smaller than or equal to 7.5 times of an upper limit of the particle size of the fine aggregate and is larger than or equal to 7.5 times of a lower limit of the particle size of the fine aggregate.