Additive manufacturing and 3D printing are rapidly developing digital fabrication techniques (Lu et al. 2015). After the first steps in small scale printing of metals (Frazier 2014) and plastics (Gibson et al. 2014) have been made, research from various groups around the world is now also focusing on large scale printing in concrete (Lim et al. 2012) and making this technology more suitable for the construction scale. The potential of using this technology is that it will be possible to create complex and/or customised concrete designs with the expectation that the costs will be low and the construction speeds will be high. Additionally, this new technology will provide opportunities to create more efficient structures. Structures can already be optimised in the early stages of the design for weight and structural performance, but the resulting optimised structures are often difficult to manufacture due to the resulting geometry of the design. Additive manufacturing can address this issue without high costs for moulds and labour.

This paper will present a novel methodology to include material performance and manufacturing constraints of 3D printed concrete in design optimisation processes. The study examines the possibility to optimise concrete structures in the design phase. In order to save material and thus create more sustainable and more cost efficient structures, a topology optimisation method has been created specifically for 3D printed concrete. Traditional topology optimisation methods consider isotropic and linear elastic material and will not necessarily produce realisable and reliable optimised structures. In the algorithm presented constraints of the printing process and material properties from physical testing of this layered material have been considered in the optimisation. By adopting this methodology more realistic and feasible optimal concrete structures can be designed. ... Read more

This paper presents the development of a novel computational framework with which expert analysis knowledge can be captured, stored and dynamically retrieved when required to determine the performance of a building design with respect to user-defined requirements. By subdividing the engineer's and designer's knowledge into discrete steps, and storing these steps in a database along with a description of the context in which the knowledge is to be applied, a searchable knowledge base is created. Given a context consisting of a BIM model and one or more building requirements for which metrics are to be provided, the applicable knowledge can be iteratively retrieved from the knowledge base. Through computational reasoning an analysis is acquired as a chain of logically connected analysis steps. Foreseen benefits of use of the framework include safekeeping and disclosure of AEC expert's knowledge and automation of analyses without loss of analysis transparency. ... Read more

This paper presents a design for a topology-optimised concrete floor slab, of which the structural optimisation process is guided by manufacturability constraints from a vacuumatic formwork. Ihe design has been obtained using an open-source, tliree-dimensional topology optimisation algorithm. Traditional floor systems are cost-optimised but can have the disadvantage of being structirrally inefficient. Topology opthnisation allows for efficient material distribution, and thus a reduction in weight. Topology-optimised floors are typically regarded as being difficuft to produce, however, and cost too much to be considered in building designs. In order to reach a compromise between a low self-weight and low production costs, two features are included in the optimisation process. First, manlifacftirability is directly incorporated in the optimisation, rather than afterwards. Secondly, the highly malleable vacuumatic formwork system by Huijben [7] has been used as a premise. Its advantages may cause the formwork costs to be reduced considerably when producing floor slabs. ... Read more