Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic Casting.

Area of Science:

• Construction Technology
• Materials Science
• Digital Fabrication

Background:

• The construction industry traditionally lags in adopting new technologies.
• Digital fabrication methods offer potential for faster, higher-quality construction with greater design freedom.
• Smart dynamic casting (SDC) is a digital slip-forming process with potential for advanced construction.

Purpose of the Study:

• To investigate the potential and constraints of smart dynamic casting (SDC) for producing thin folded concrete structures.
• To establish a material-focused approach for optimizing SDC processes.
• To develop a theoretical framework linking material properties, process conditions, and geometry for SDC.

Main Methods:

• Studied workability and strength evolution of various concrete compositions for consistent SDC processing rates.
• Investigated concrete-formwork friction using a simplified experimental setup.
• Developed a theoretical framework, introducing the 'SDC number,' to define the process window for slip-forming.

Main Results:

• Experimental results confirmed friction is proportional to yield stress, irrespective of base composition or acceleration method.
• Identified initial friction as highest, suggesting easier continuation after successful startup.
• Demonstrated the necessity of consistent strength evolution for narrow process windows, like those for thin folded structures.

Conclusions:

• The developed theoretical framework and 'SDC number' provide a simplified approach to formulating the SDC process window.
• Material properties significantly influence SDC success, particularly for complex geometries like thin folded structures.
• The findings enable material and geometry-specific strategies for optimizing SDC start times and slipping rates in production.