Bruil – Prediction of Print Success for Concrete 3D Printing #SWI2019

Bruil Beton & mix is specialized in the production of concrete for all kinds of applications. In the past years, Bruil has developed a new, exciting technique that has revolutionized this sector: the production of prefab elements using concrete 3D printing. This development offers architects a completely new scale of design possibilities in form, color, and structure.

3D printing starts with a digital 3d model of the object. From this 3D model, a print path is created, based on the required layer width and height. Code based on the created print path will steer the movements of the concrete printer. Using these movements to deposit concrete at the right locations, the 3D printing process thus results in a printed concrete object.

There are several difficulties with the 3D printing of concrete.

One of the difficulties is that concrete is a material of which the properties change during the drying process. Furthermore, these properties quite strongly depend on external conditions. Therefore, in practice, there are many variables that influence the printing result and thus determine whether a print will be successful: material properties, environmental conditions, rheology, the shape of the growing object, print speed, etc.

Second, not all structures dreamt up on the drawing table can be easily produced with 3D printing. During the printing process, the emerging structure could start to bend, collapse, and/or deform, depending on geometry and material properties. For example, concrete may show a phase transition. So, the drying and printing process should be fine-tuned, to allow for efficient, fast, and reliable production of 3D objects.

Based on experience alone it is hard to predict whether a print will be successful and have the expected product quality. The challenge in this project is to gain insight and deduce rules of thumb and not to apply large scale simulations. The key question is if it can be predicted in general whether a given geometry is printable. Data on both successful and unsuccessful experiments are available.