What are important pain points in 3D printing of buildings?

(14-06-2021) Jolien Van Der Putten investigates this research question in her PhD ‘Mechanical Properties and Durability of 3D Printed Cementitious Materials'.

3D printing of cement bound materials is an innovative technique that is gradually making its appearance in the construction world. Automating the construction process has many advantages: it saves costs, reduces construction time and allows the complexity of the design to be increased.

However, the layer-by-layer construction of structural elements also has disadvantages. First of all, the adhesion between the layers plays an extremely important role and largely determines the structural capacity and durability of the material. Due to the lack of formwork, the material is also much more sensitive to shrinkage and the development of cracks.

In order to get a complete picture of the material behaviour after extrusion, this doctoral research made a comparative study between elements manufactured in the traditional way and with the help of printing technology. The influence of two printing parameters (printing speed and time gap) was closely examined for both mechanical properties and durability aspects. This comparative study revealed that the interlayer (the zone between two printed layers) is extremely important. A decreased quality of the interlayer, due to for example the inclusion of pores or drying in case of enlarged time gaps, negatively affects the structural capacity of the element and creates additional preferential ingress paths for hazardous chemical substances.

To counteract the major bottle necks of this innovative technique, namely the adhesion between the layers and the shrinkage, different modifications were proposed and investigated.

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View the full PhD

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Contact: Jolien Van Der Putten

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Editor: Jeroen Ongenae - Final editing: Ilse Vercruysse - Illustrator: Roger Van Hecke