Additive manufacturing (AM) is a core technology on the paradigm shift to Industry 4.0 and has already impacted health, aerospace, automobile, military, fashion fields, and, more recently, construction. The most widespread AM method in the construction industry is 3D cementitious material printing (3DPCC). The main advantage is the freeform architectural design without formworks needed. Increased productivity, reduced costs, more safety worksites are potentially expected, and environmental benefits within materials savings and waste generation reduction. The freeform architecture and precision material placement make 3D printing particularly exciting for architectonic purposes, such as structures, buildings or elements. From the perspective of materials science, 3DPCC mix-proportioning remains one of the most critical aspects due to (i) the very demanding requirements, namely at fresh state; (ii) the needing of several constituent materials; (iii) the sensitivity of the mixtures to natural variations. The current work aims to add insight into the mixture design and assessment of architectonic 3PPCC through cooperation between science and industry. Employing locally available materials, establishing a rational basis for preparing and designing 3DPCC, applying novel testing procedures, providing understandings, and certifying its behaviour are fundamental questions. Thus a mix compositions study was accomplished, using locally available materials in Turkey, namely, white Portland cement and metakaolin. A systematic choice of fresh state parameters and identification of their threshold values to achieve printable mixtures, such as flow table and Casagrande, was established. Afterwards, the optimal mixture was employed to print architectonic objects, and additional tests were performed on samples. This works aimed to contribute to 3D printing as a way for the paradigm shift to Industry 4.0 and stimulate the adoption of clean and environmentally sound technologies and industrial processes in the Construction Sector. Besides, a straight collaboration among the scientific community and industry is essential to make 3D printing a more practical, cost-effective, eco-efficient and widely accepted technology.
