Abstract

The growing demand for sustainable structural materials has led to the use of Glued Laminated Timber (GLT) in contemporary construction, including bridges and small-to-large-scale infrastructure projects. Bridges are subject to repeated vehicular loads, making fatigue and cyclic performance essential considerations in their design. This study examines the flexural performance of GLT beams for structural applications through experimental testing, theoretical analysis, and Finite Element (FE) modelling. Full-scale four-point bending tests under monotonic and cyclic loading conditions revealed that beams tested under monotonic loads exhibited higher strength, displacement, and energy dissipation. On the flip side, cyclic loading provided critical insights into the durability and serviceability performance of GLT beams.
FEM were validated using experimental results. These models effectively captured the non-linear response of GLT beams, allowing parametric studies that highlighted the significant influence of beam geometry on stiffness and energy absorption. Hybrid reinforcement strategies were assessed to improve the structural performance of GLT beams, utilizing steel in tension and Fibre Reinforced Polymers (FRPs) in compression. Experimental benchmarks informed FEM simulations of reinforced beams with varying bar spacings and reinforcement ratios. CFRP-steel hybrid configurations produced the most substantial improvements in both strength and stiffness, achieving more than twice the capacity of the reference (unreinforced) beams. While GFRP and BFRP hybrid reinforcement configurations yielded moderate enhancements, reaching approximately one-half of the capacity increase observed in reference GLT beams. The combination of experimental data with validated FE modelling advances the structural application of GLT beams in engineered timber bridge design. The results address gaps in current standards (CSA O86, CSA S6:19) and demonstrate that hybrid reinforcement substantially improves flexural strength, stiffness, and ductility. These findings advance sustainable, high-performance timber structures for modern infrastructure.