Instantaneous and long-term structural behavior of timber-flax beams: Design and evaluation of the hybrid flax pavilion component

The construction industry significantly contributes to global carbon emissions and resource depletion, necessitating a transition toward more sustainable materials. Renewable materials show high potential as an alternative to conventional fossil-based materials in mitigating climate change within the construction industry. Diversifying the sourcing, especially for plant-based materials, is imperative to ensure sustainability and prevent overreliance on specific resources. In prior studies, Coreless Filament Wound (CFW) natural fiber-reinforced polymer (NFRP) systems have demonstrated promising material efficiency and structural performance. However, the lack of research on their long-term performance in construction applications presents a significant barrier to widespread market adoption. This study addresses this gap by designing, developing, and evaluating the Hybrid Fibre Pavilion constructed for the 2024 Landesgartenschau in Wangen im Allgäu. The pavilion incorporates simply supported beams fabricated from robotically wound NFRPs and cross-laminated timber (CLT) slabs. Full-scale structural components were robotically manufactured and subjected to distributed ultimate load, creep, and cyclic load tests. The findings highlight the viability of this hybrid structural system, demonstrating its potential for robust instantaneous and long-term performance in construction. • Design strategy of material allocation and orientation of fibrous structures • 1000-hour creep deformation of the hybrid beam is comparable to that of timber • Cyclic fatigue testing revealed a 3.5% structure strength loss over 100 cycles. • Sustained load over 1000 hours revealed a structure strength loss of 7% • The projected strength reduction of the hybrid beam at 50 years is estimated as 13.1%