An experimental study of the behavior of 3D printed concrete at elevated temperatures

3D printing of concrete (3DPC) is an automated layer-wise construction technique that does not require temporary support, such as formwork, during the construction process. It facilitates the realization of geometrically complex objects at reduced construction time, and potentially cost, compared to conventional construction techniques. However, with technological advancements and new innovative construction methods, such as 3DPC, it is still crucial to understand their performance in fire. Although concrete structures generally have a good reputation for their behavior in fire, there is negligible literature available on the behavior of 3DPC at evaluated temperatures. It is with this backdrop that this paper conducts a preliminary investigation on the behavior of 3DPC at elevated temperatures by conducting an experimental study. Eight concrete samples, consisting of both 3DPC and conventionally casted concrete, were tested by exposing the samples to a high incident heat flux via radiant panels, along with an additional 15 samples to obtain ambient strength properties. It was found that 3DPC is less susceptible to thermo-hygral spalling as a result of higher permeability and porosity in the 3DPC specimens compared to normally casted concrete. However, the 3DPC samples delaminated between layers (thermo-mechanical) as a result of reduced flexural strength.