Reinforcement Strategies for Additively Manufactured Concrete Elements

Selective cement activation (SCA) in additive manufacturing of concrete holds promise for sustainability by enabling localized cement hydration through controlled water application and allowing a wider range of possible geometries for structural elements. However, SCA-based concrete elements face limitations in tensile strength, restricting their construction versatility. Moreover, SCA’s manufacturing process constraints reinforcement options, necessitating strategic choices to improve mechanical properties while aligning with sustainability principles and the specific process requirements. This study investigates innovative reinforcement strategies to enhance the mechanical performance of SCA-based concrete elements using recycled foam glass as aggregates. We examine reinforcement materials, including sustainable ones such as basalt. The materials assessed include steel bars, stainless steel cables, basalt bars, carbon fiber rovings, and carbon fiber meshes. Steel bars are evaluated for both in-process and post-printing applications, while all other materials are integrated solely during printing. The study reveals that steel bars, mainly when introduced through subsequent grouting, offer an efficient means to significantly enhance the mechanical properties of SCA-based concrete elements. However, alternative materials like basalt and carbon fibers may face challenges in establishing an effective bond with the printed concrete material. In conclusion, this paper underscores the importance of sustainable reinforcement strategies for SCA-based concrete elements, emphasizing the potential of steel bars and encouraging further exploration of eco-friendly alternatives.