Procedural print-path generation and optimisation for inclined-plane robotic printing of unreinforced concrete

Bhooshan S., Bhooshan V., Megens J., Van Mele T. and Block P.
Digital Concrete 2022 - Third RILEM International Conference on Concrete and Digital Fabrication

The paper details the toolkit for print-path synthesis and execution that was used in the physical realisation of an arched, bifurcating, unreinforced masonry footbridge spanning 16 metres, composed of 53 blocks of 3D-printed concrete. The printed concrete filaments of every block are placed in layers that are orthogonal to the expected, compressive force flow, resulting in the need for non-parallel, inclined print-path planes, thus also resulting in non-uniform print-layer heights. In addition, the bridge’s global structural logic of stereotomic masonry necessitated the precise coordination of the interface planes between blocks. Approximately 58 kilometres of print-path, distributed over 7800 inclined layers, were generated and coordinated such that the resulting print-paths meet printing-related criteria such as good spatial coherence, minimum and maximum layer thickness, infill patterns etc.

Bhooshan et al. (2018, 2020) describe a Function Representation based schema for inclined-plane print-path generation. We describe the full implementation and extension of the schema for practical and large-batch production. We also implement specific extensions to generate the infill print-paths typically needed in 3D concrete printing. Furthermore, we also describe the refinements incorporated into the print-processing toolkit, subsequent to the discoveries made during the physical realisation of the bridge.

Thus, the custom toolchain that was developed enables print-path synthesis, verification and generation of robotic instructions or so-called GCode. The toolchain and the constituent, standalone applets were designed to enable rapid iteration and refinement, whilst being free of external dependencies. Together, the toolkit provides a blueprint for real-time, printing-aware, interactive shape design. The fast print-processing enabled by the toolkit also makes it a suitable starting point for non-parallel ‘slicing’ of user-defined, input shapes.


    author    = "Bhooshan, S. and Bhooshan, V. and Megens, J. and Van Mele, T. and Block, P.",
    title     = "Procedural print-path generation and optimisation for inclined-plane robotic printing of unreinforced concrete",
    booktitle = "Digital Concrete 2022 - Third RILEM International Conference on Concrete and Digital Fabrication",
    year      = "2022",
    editor    = "",
    volume    = "",
    number    = "",
    pages     = "",
    publisher = "",
    address   = "Loughborough",
    month     = "",
    doi       = "",
    note      = "abstract submitted for review",

Related publications

Bhooshan S., Van Mele T. and Block P.Morph & Slerp: Shape design for 3D printing of concrete,ACM Symposium on Computational Fabrication (SCF) 2020,Cambridge,2020.
Bhooshan S., Ladinig J., Van Mele T. and Block P.Function representation for robotic 3D printed concrete,ROBARCH 2018 - Robotic Fabrication in Architecture, Art and Design 2018,: 98-109,SpringerZurich,2018 (September).
Bhooshan S., Van Mele T. and Block P.Equilibrium-aware shape design for concrete printing,Humanizing Digital Reality - Proceedings of the Design Modelling Symposium 2017,K. De Rycke et al. (editors),: 493-508,SpringerParis,2018 (September).


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