Composite Cementitious Feedstock for 3D Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing concrete 3D printing systems face challenges with controlling the viscosity and curing of wet concrete slurry, leading to thermal runaway issues, difficult cleanup, and the need for extensive cleaning procedures, which complicates the construction process and can result in structural weaknesses due to poorly mixed concrete.
Innovation Solution
A composite cementitious feedstock comprising mineral rock agglutinates, super absorbent polymer particles, and cement particles, held together by a binder that dissolves upon activation with water or electromagnetic energy, allowing for dry transportation and on-site hydration, reducing the complexity of mixing and application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wet Portland cement concrete slurry is used for 3D printing, then the material can be extruded to form additive layers, but the system suffers from thermal runaway issues, difficult cleanup, and requires extensive cleaning procedures
Solution Approach 1:
The concrete mixture is segmented into discrete elements or pellets containing cement, aggregate, and water-absorbing polymer particles. This segmentation allows dry storage and transport of components, eliminating the need for complex mixing systems and extensive cleanup procedures while maintaining printability when activated with water
Solution Approach 2:
The invention changes the physical state parameter of the concrete from wet slurry to dry discrete elements. This parameter change eliminates thermal runaway issues during storage and transport, simplifies cleanup operations, and allows for on-demand mixing at the construction site by adding water to activate the cement and bind the discrete elements
2Stability of the object's composition
If wet concrete slurry is transported and applied, then continuous concrete structures can be formed, but the slurry must be maintained at correct viscosity to prevent slumping or crumbling
Solution Approach 1:
The discrete elements are pre-prepared with cement and aggregate in correct proportions and contained within water-absorbing polymer particles. This preliminary action ensures proper mixing ratios are maintained during transport and storage, eliminating the need for complex viscosity control while ensuring structural integrity when activated
Solution Approach 2:
Water-absorbing polymer particles serve as an intermediary that controls the release of water to the cement mixture. This intermediary mechanism automatically regulates viscosity and prevents slumping or crumbling by controlling hydration timing, simplifying handling operations while maintaining structural integrity
3Reliability
If cement particles are mixed with water to initiate hydration, then the concrete cures and hardens, but the exothermic reaction makes it hard to control the curing properties
Solution Approach 1:
The cement hydration process is segmented into discrete elements that are activated individually or in controlled batches. This segmentation distributes the exothermic reaction across multiple small sites rather than one large volume, improving thermal control and curing consistency while maintaining reliable hardening
Solution Approach 2:
The cement, aggregate, and water-absorbing polymer are pre-mixed in discrete elements before hydration begins. This preliminary preparation ensures uniform distribution of components and controlled water release, leading to consistent curing properties and better thermal management during the exothermic reaction
4Ease of operation
If dry discrete elements are used, then transportation and storage are simplified, but the binder must dissolve or dissipate at activation to release the discrete elements
Solution Approach 1:
The water-absorbing polymer particles automatically dissolve or dissipate when exposed to water, releasing the cement and aggregate discrete elements without requiring external intervention. This self-service mechanism simplifies the activation process while maintaining ease of transport and storage of the dry mixture
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
This solution enables efficient, controlled concrete production and application, simplifying the construction process, reducing material handling issues, and ensuring consistent structural strength by allowing for precise mixing and activation at the construction site, thereby improving the quality and efficiency of 3D printed structures.
Implementation Method 1
super absorbent polymer (SAP) particles
Implementation Method 2
The SAP particles are disposed on the irregular surface regions and in the cavities
Implementation Method 3
The binder coheres the agglutinates, SAP particles, and cement particles
Implementation Method 4
a binder that dissolves upon activation with water or electromagnetic energy
Implementation Method 5
activation with water or electromagnetic energy
Implementation Method 6
The addition of water initiates a hydration process that causes an exothermic chemical reaction that ultimately results in the curing and hardening of the concrete material
Implementation Method 7
The addition of water initiates a hydration process that causes an exothermic chemical reaction
Data Source
AI summary
A composite cementitious feedstock includes mineral rock agglutinates, super absorbent polymer (SAP) particles, cement particles, and a binder. Each of the agglutinates has irregular surface regions and cavities originating at the irregular surface regions. At least a portion of the SAP particles and cement particles are disposed on the irregular surface regions and in the cavities. The binder coheres the agglutinates, SAP particles, and cement particles.