Concrete joints classification improves design for reusable structures
JOINTS: Classification and analytical evaluation of detachable dry connections for reusable concrete elements
Computational Engineering, Finance, and Science
Summary
Reusing concrete parts in buildings means connecting them firmly but also in ways that can be undone later. The authors created a clear system, called JOINTS, to describe different types of dry connections that can be detached and reused. They tested three joint designs to see how well they handle forces and found that making complex shapes doesn’t always help much because concrete itself limits strength. Their work helps make better, more sustainable concrete connections that can be taken apart and reused.
What this means in practice
- •For structural engineers: Design reusable concrete connections with clear guidelines to optimize strength and sustainability based on JOINTS classification and analytical evaluation.
- •For construction project managers: Plan structural reuse by selecting detachable concrete joints that balance cost, durability, and easy disassembly using quantified evaluation criteria.
Authors
Julius Fründt, Vladislav Gudžulić, Günther Meschke, Roger A. Sauer
Abstract
This paper presents a systematic classification for detachable dry joints suitable for the structural reuse of reinforced concrete elements, together with an analytical evaluation of representative configurations. The classification, named JOINTS and applicable to concrete connections beyond the reuse context, organizes the design space along five categories whose initials spell JOINT: the Juxtaposition (spatial arrangement of the paired elements), the Origin (their prior structural function), the Interface geometry, the Newly introduced materials at the joint, and the force-Transfer mechanism. A sixth category, the Score, completes the acronym and evaluates each configuration for sustainability, cost-efficiency, and mechanical performance. From this design space, three representative configurations are evaluated analytically under active post-tensioning, differing in both their joint geometry (planar, stepped, and angled) and their tendon inclination. The evaluation covers failure of the anchorage of the post-tensioning member, the contact limit of the interface, and the material limit of the concrete adjacent to the interface. Although complex joint geometries theoretically enhance interlocking, their benefit is limited by the compressive-shear strength of the concrete. The reinforcement of the reused elements may be damaged near the cut, and the splitting reinforcement that a conventional design would require is not guaranteed to exist. The present analysis therefore conservatively assumes that the concrete at the joint face alone resists the combined compression and shear, neglecting any residual contribution from the existing reinforcement. This analytical evaluation represents a first step toward quantifying the score over a parametric range of connections, here focusing on the mechanical criterion.