Optimal casting window defined by electrical resistivity for enhancing interfacial bond strength in 3D printed-cast concrete composites
Year: 2025
Type: article
Abstract: Integrating 3D printed concrete with conventionally cast concrete offers a hybrid pathway for fabricating large-scale composite structures. The structural reliability of such systems depends critically on the mechanics of the printed-cast concrete interface. This study investigates the effect of casting time on interfacial bonding and proposes an electrical resistivity monitoring to identify the optimal casting window. A non-destructive monitoring system was developed to track the early-age hydration and setting behavior of printed concrete formworks, with post-cast concrete placed at selected intervals. Bi-surface shear tests revealed a clear transition in failure modes with increasing delay: samples cast at the optimal casting window (CSW) exhibited the highest shear strength (up to 3.49 MPa), cohesive fracture within the post-cast concrete, and the greatest fracture energy, whereas delayed casting (72 h) resulted in adhesive failure and brittle delamination. Scanning electron microscopy further confirmed widening and porosity of the interfacial zone with prolonged delay. These findings demonstrate that electrical resistivity monitoring not only provides a rational and non-destructive basis for casting decisions but also establishes quantitative correlations between material state evolution, interfacial mechanics, and fracture behavior. The proposed approach advances the engineering of hybrid 3D printed-cast concrete composites by enabling improved interfacial bond performance, structural integration, and efficient additive manufacturing workflows.
Authors: Jin Soo Bang, Seong Jun Ha, Yubin Jun, Hong Jae Yim
Language: English
Subfield: Building and Construction
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,540
Award: G2256767677
OpenAlex ID: W7117378564