In recent years, digital construction methods, such as 3D-printing with concrete, have seen a surge in interest. They address many challenges currently encountered in the construction industry. However, for the digital construction to be successful, both in terms of sustainability and cost-effectiveness, the 3D printable materials must fulfil high requirements, particularly regarding their rheological and mechanical properties. The use of environmentally friendly materials with low clinker content, such as Limestone-Calcined-Clay-Cement (LC³), could further reduce the carbon footprint of these processes. Additionally, integrating recycled aggregate into the 3D printable mix (Printable Recycled Aggregate Concrete: PRAC) could promote resource conservation, environmental protection, and energy efficiency. This study investigates the time-dependent development of the static yield stress and the structural build-up by means of a rapid penetration test and a newly proposed modified cone geometry. These tests enable to realistically describe the material behaviour of new, environmentally friendly 3D printable mixtures with coarse aggregates. The results attained provide a foundation for future efforts to use demolition materials more efficiently in 3D concrete printing.