Comparison between mono- and bi-component extruders in concrete additive manufacturing

Abstract

In a growing mobilisation against climate change, the reduction of the impact of the construction sector is becoming a priority. To achieve this reduction, among the topics to be improved (transport, fine particle emission, water depletion, soil contamination), the global warming potential (GWP) of concrete is clearly the one with the most impact. Cement is the second most used product in the world and emits CO2 in all of its life cycle phases. In absence of a satisfactory alternative, a reduction of the amount of material used is a promising and straightforward path to reduce its impact. Casting, the current method to employ concrete, is inherently inefficient due to constraints of the formwork mould. Additive manufacturing is an interesting alternative to overpass the limitations of the casting process as already proven in other sectors. The implementation of 3D concrete printing (3DCP) is entangled between a tendency for an easy quick cost-effective implementation and the ability to achieve complex structures that require more advanced methods. From the final impact point of view, the bi-component solutions seem to give more promising results than mono-component solutions.