A NOVEL LIMITED-DAMAGE 3D-PRINTED INTERLOCKING INTER-MODULE CONNECTION SYSTEM FOR CROSS LAMNINATED TIMBER (CLT) VOLUMETRIC STRUCTURES

Abstract

With both the sustainability of timber and efficiency of modular construction, Cross Laminated Timber (C L T) volumetric construction is considered a potential solution to the severe environmental impact of modern construction. Conventional connection systems of C L T modular structures (angle bracket, hold-down) are mainly designed for panelised and framed construction. Due to their nature, they require careful design while numerous damages have been reported not only on their steel components but also timber fibres. The U K ' s funded project 3DMBC (https://3dmbc.com) was established to explore new ways of connecting C L T volumetric modules, ideally being damage-free and self-locking onsite during installation, aiming to improve the efficiency, adaptability and reusability of C L T volumetric construction. Damage avoidance philosophy (controlling deformation and damage away from timber and the embedded fasteners) was a key objective in the design of a three-dimensional connector system. A novel inter-locking system was recently proposed, tested experimentally and validated via numerical analysis. The proposed connection design also showcases a new concept of module assembly in C L T volumetric construction with higher efficiency, flexibility and adaptability, meanwhile demonstrates the potential in mitigating (permanent) damage of timber, thus increase service life and enable disassembly and reuse operations. The study shows that the screw-free assembly was provided along with adequate stiffness, strength and ductility by the new connections, and no damage was observed in timber after testing, proving the feasibility ofthe new connection design.