Robustness of Digital Concrete: Effects of Temperature, Accelerator Type and Dosage

Digital fabrication of concrete has increasingly gained attention from scholars and industrial investors during the past several years. However, the proper concrete mix for such applications needs to meet stricter criteria compared to conventional concrete casting, due to the higher process demands. This leads to a shortcoming in this technology, which is that digital concrete mixes are more sensitive to minor variations in mix proportioning, properties of the incoming materials, and environmental conditions such as temperature. 3D printing of concrete, which is one of the main subdivisions of digital concrete, can be further categorized into 1k and 2k systems. This work focuses on 2k systems, which includes a secondary mixing step for the addition of an accelerator, omitted in 1k systems. In this study, the robustness of different accelerating systems was investigated and compared. Two accelerating systems were studied respectively based on Calcium Aluminate Cement pastes (CAC) and Aluminum Sulfate solutions (A$). The accelerated mixes are subjected to dosage as well as temperature variations. The obtained results are discussed in view of enhancing the robustness of digital concrete.