3D concRetE durAbility iMprovement (3DREAM)

Abstract

3D printed concrete can be described as revolution conquering the modern construction field. However, many uncertainties are still perusing additive manufacturing imposing several limitations such as the interfaces of successive layers. This technology is standing behind the wall of being environmental friendly and its market is widening its horizons by implementing 3D printed concrete in harsh environments such as bridges and infrastructures. In this regards, the durability of those structures should be assessed since the earth cannot afford redoing the same structure several times without mentioning the cost and damages caused by the sudden failure of structures. This study consists of studying the durability of 3D printed concrete by comparing casted and printed samples aged by sulfuric acid attack. Three different mixes were subjected to a low concentration (0.5%) of sulfuric acid over 140 days on one hand, and same mixes were cured in water on the other hand. In addition to visual inspection of the samples, the mass loss was recorded periodically. Moreover, the mechanical performance was evaluated and recorded. Both printed and casted samples showed degradation when placed in acid but the printed ones slightly resisted better. However, after 84 days, both printed and casted became equal in resistance. In addition, the mechanical performance came in accordance to the mass loss to prove that printed samples resisted well the acid attack although the casted ones have higher recorded strength. During this study, no weak interfaces were present. In contrast, the printed samples performed as one block.