Ribbed CFRP-Reinforced Ceilings Reinvented: Optimization of Nervi’s Principles Using Multimodal Digital Fabrication Methods

Abstract Floor slabs are among the most material-intensive structural elements in buildings and therefore offer significant potential for reducing concrete consumption and associated CO 2 emissions. At the same time, the realization of material-efficient slab geometries remains limited by labor-intensive construction methods and challenges related to automation. To address these issues, this paper presents a modular ceiling system that combines historical principles of material efficiency, as pioneered by Pier Luigi Nervi, with digital fabrication technologies. Individual ceiling modules are fabricated using a multimodal production process that integrates extrusion-based three-dimensional concrete printing (3DCP), robotic casting, and automated placement of carbon fiber-reinforced polymer (CFRP) reinforcement. By combining prefabricated modules through dry-joint connections and post-tensioning, the system enables efficient on-site assembly while achieving significant reductions in concrete consumption and allowing for potential reuse of components. This paper discusses reinforcement integration challenges in the 3D printing process and the development of a digital production workflow. A full-scale prototype demonstrates the feasibility of the approach, while ongoing research explores robotic milling of early-age concrete to improve joint precision and advance automation.