Experimental investigation on the bending response of reuse-ready timber slabs – The Pixel Slab System

Current construction practices follow linear economic models of "take-make-dispose" that result in substantial material landfilling after the end-of-life of buildings. This issue takes relevance given the construction industry's significant stake in the high levels of resource depletion and waste production observed today. As an attempt to address the problem, this paper presents an experimental investigation on the bending behavior of glue-laminated timber (GLT) slabs -Pixel Slab System- designed for openended reuse following Circular Economy principles. The system employs an arrangement of orthogonally intersecting GLT beams to form a reuse-ready grid slab, relying on adjustable static heights, reversible connections, and modular elements to guarantee easy disassembly and reassembly in unknown configurations. To evaluate the system performance, twelve full-scale GLT beams were tested under bending load, employing different spans, depths, and connection placements. Results showed that the system has adequate performance under 3- and 4-point loads; however, the use of notches at the intersections reduced its stiffness and moment capacity by 23% and 29%, respectively. Using reversible steel connections to join consecutive slab modules proved to deliver a proper mechanism to transfer axial, shear, and bending loads, while not affecting the elastic response or failure mode of the beams. Finally, a constructability analysis showed that the concept poses no constraints to on-site construction/deconstruction, since low-tech procedures are used for assembly/disassembly.