Demountable connections for structural concrete reusability: State of the art and future directions for reinforced concrete, Part I: Slabs

This paper reviews demountable concrete slab connections as a strategy for reusing precast and existing reinforced concrete elements, with a focus on dry and semi-dry joints that enable assembly and disassembly. It analyses slab-to-slab and slab-to-beam connections, comparing solutions that differ in complexity, level of development and validation, and steel usage. Connections are analysed for two groups: precast slabs and monolithic concrete slabs cut for future reuse. Most proposed solutions are bolted dry connections, typically at a conceptual stage, with limited experimental validation. While some demountable precast joints can achieve performance close to that of monolithic systems, experimental results generally show reduced stiffness and load-bearing capacity. Reuse performance also tends to decline slightly in subsequent life cycles, highlighting the need for validation beyond initial use. Key factors such as slab rigidity significantly influence structural behaviour but remain insufficiently studied. Overall, wider practical application requires more comprehensive experimental and numerical research, especially beyond the first life cycle and system-level performance, along with integration into design standards.