Properties of Extrusion-Based 3D Printable Geopolymers for Digital Construction Applications (2019-02)¶

Additive manufacturing (AM), commonly known as three-dimensional (3D) printing is rapidly transforming manufacturing, aerospace, and medical industries. It has “the potential to revolutionize the way we make almost everything” as said by the former US President, Barack Obama in his state of the union address. If the 3D printing can be used with concrete, it can potentially change the way we build concrete structures, saving huge costs in formworks and allow freeform construction. Freeform construction would enhance architectural expression, where the cost of producing a structural component will be independent of the shape, providing the much-needed freedom from the rectilinear design [1,2]. In the past few years, several emerging 3D concrete printing (3DCP) technologies have been explored in the construction industry. These 3DCP technologies are principally based on two techniques, namely: (1) powder-based; and (2) extrusion-based techniques. The powder-based 3DCP technique is an offsite process, which has the potential to make building components with complex geometries such as panels, permanent formworks and interior structures which can be later assembled onsite [1,2].There is a demand in the construction industry for such components. Based on the available construction systems, the use of expensive formworks are essential to build such components. The powder-based 3DCP technique can satisfy this industrial demand as it is capable ofmaking robust and durable building components at a reasonable speed without the use of expensive formworks. However, the commercially available powder-based 3D printers usually use proprietary printing materials, which are not suitable for the construction applications. To tackle this limitation, the authors of this study developed an innovative methodology to adopt geopolymer materials in commercially available powder-based 3D printers for construction applications [2-9].