Tailoring localized interfacial patterns of meta-rebars to improve strength and ductility of architected cementitious composites

Abstract

<p>Architected cementitious composites (ACC), featuring 3D-printed reinforcement with programmable interfacial patterns, offer a promising approach to tailor the mechanical response compared to conventional fiber-reinforced composites. However, the critical role of the interface in dictating the overall mechanical performance of ACC is often overlooked. To address this gap, this study investigates how localized interfacial designs affect ACC performance, focusing on the bond-slip mechanism, compressive strength, and flexural capacity. A series of 3D-printed meta-rebars with tailored surface patterns—such as round, re-entrant, and honeycomb ribs—was developed to enhance reinforcement–matrix adhesion. Pull-out tests demonstrated that these metamaterial interfaces increased bond strength by up to 226 % over smooth rebars, with honeycomb ribs exhibiting the highest performance. Compression tests revealed that re-entrant rib designs optimized both compressive strength and energy absorption, while an optimal rib height-to-diameter ratio (h/d = 0.11) maximized the load-bearing capacity. Flexural tests further showed that round-rib interfaces provided the highest flexural strength, though interfacial design distribution significantly influenced ductility and energy absorption. Finite element simulations enlightened stress distribution variations within the architected lattice reinforcement. This study paves the way for the development of performance-driven, sustainable cementitious materials with enhanced durability and energy efficiency, while highlighting the potential of additive manufacturing and programmable interface designs to advance reinforcement strategies in next-generation cementitious composites.<br></p>