Bamboo and Arundo donax for the future of european construction: unlocking their structural potential through a multiscale investigation

To address the growing demand for sustainable and high-performance construction materials, this thesis explores the structural potential of two natural resources: bamboo and Arundo donax. Though widely available and environmentally low-impact, bamboo and Arundo donax also exhibit promising mechanical properties. However, they remain underused, especially in Europe, due to insufficient scientific validation and persistent outdated perceptions. Through a rigorous multiscale approach, this research aims to build a scientific basis for their integration into contemporary European construction. The study is structured across three interrelated scales. At the microscale, six bamboo species cultivated in Italy, Phyllostachys edulis, bambusoides, viridiglaucescens, vivax, iridescens, and violacescens, were compared with Arundo donax through detailed anatomical analysis. Microscopy and image-based quantification revealed their differences, highlighting their influence on mechanical performance. Moreover, the results significantly contribute to the growing body of knowledge on European bamboo species. At the mesoscale, the link between internal structure and mechanical behaviour was explored, leading to the development of predictive tools for estimating both longitudinal and transverse properties. Analytical and numerical FEM simulations were carried out. A fast and accessible flexural test was also developed and validated for small European bamboo. Its effectiveness has been demonstrated both as a material grading method, similar to those used for timber, and for assessing degradation, as shown by a UV ageing campaign on P. viridiglaucescens. At the macroscale, the research translates material knowledge into practical structural systems. A multi-culm bamboo bundle beam and a full-span arch structure, based on the existing CanyaViva technique, were studied through experimental testing and numerical simulation. Bamboo offers greater load capacity, while Arundo donax exhibits higher ductility. By bridging gaps in scientific knowledge and perception, this thesis encourages the incorporation of bamboo and Arundo donax into sustainable construction paradigms rooted in local and renewable resources, in Europe and beyond.