3D Concrete Printing on Site: A Novel Way of Building Houses?

As a result of the constantly increasing world population and its purchasing power, it becomes more and more clear that raw materials are finite and the capacity of the earth to renew the stock of raw materials is almost exceeded. This is also important for construction industry as half of the extracted materials and about one third of the water consumption is absorbed by this sector. During the last years, a lot of progress has been made in creating more energy efficient buildings, but unfortunately, construction represents at this moment still 40% of the energy demand in Europe and 36% of the total CO2 emission [1]. However, the construction sector offers significant potential to handle these struggles and a possible solution to improve the sustainability is through automated construction by for example 3D printing the structural components. This new way of manufacturing has the advantage that there is no need for energy demanding and expensive molding, there is a larger freedom of form and there is the opportunity to use the material in a more eco-friendly way since it is only used where necessary. However, before acceptation of this technique on the construction site, it is necessary to compare the structural behavior of printed and cast specimens. For that reason, two wall types were tested on their compressive strength and also two types of reinforcement above a window opening were investigated through 3-point bending tests. These results showed that, in general, the mechanical performance of the suggested wall types is greater than that of traditional walls consisting of brickwork. This, in combination with the lack of molding and the higher construction speed, can accelerate the application of 3D printing on site.