Non-planar Printing of Construction Elements

Abstract

This doctoral thesis investigates the application of non-planar slicing in construction 3D printing, addressing the limitations of conventional planar slicing techniques. Construction 3D printing relies on materials such as concrete, cementitious mixtures, geopolymers, and clay, which are extruded in large volumes within short timeframes. Unlike plastics and metals, these materials have longer setting times, posing challenges to buildability and printability. Planar slicing, which divides CAD models into uniform horizontal layers, is widely used but introduces significant drawbacks, including the stair-stepping effect, limited overhang printability, and anisotropic mechanical behaviour. Non-planar slicing, which incorporates Z-height variations, offers a promising alternative by enhancing surface quality, improving geometric accuracy, and optimizing structural performance. While non-planar slicing has been extensively explored in polymer-based additive manufacturing, its adoption in constructionscale 3D printing remains underdeveloped. This dissertation bridges the gap between the proven advantages of non-planar slicing in polymer-based manufacturing and its potential in construction 3D printing. Through comparative experiments and real-world case studies, the research evaluates non-planar slicing strategies for clay, cementitious materials, and geopolymer-based printing. Experimental testing validates its feasibility, demonstrating that non-planar slicing significantly enhances print quality and expands design possibilities. These findings provide a foundation for advancing construction 3D printing processes, enabling more innovative and efficient building practices.

This doctoral thesis investigates the application of non-planar slicing in construction 3D printing, addressing the limitations of conventional planar slicing techniques. Construction 3D printing relies on materials such as concrete, cementitious mixtures, geopolymers, and clay, which are extruded in large volumes within short timeframes. Unlike plastics and metals, these materials have longer setting times, posing challenges to buildability and printability. Planar slicing, which divides CAD models into uniform horizontal layers, is widely used but introduces significant drawbacks, including the stair-stepping effect, limited overhang printability, and anisotropic mechanical behaviour. Non-planar slicing, which incorporates Z-height variations, offers a promising alternative by enhancing surface quality, improving geometric accuracy, and optimizing structural performance. While non-planar slicing has been extensively explored in polymer-based additive manufacturing, its adoption in constructionscale 3D printing remains underdeveloped. This dissertation bridges the gap between the proven advantages of non-planar slicing in polymer-based manufacturing and its potential in construction 3D printing. Through comparative experiments and real-world case studies, the research evaluates non-planar slicing strategies for clay, cementitious materials, and geopolymer-based printing. Experimental testing validates its feasibility, demonstrating that non-planar slicing significantly enhances print quality and expands design possibilities. These findings provide a foundation for advancing construction 3D printing processes, enabling more innovative and efficient building practices.