The giant reed, Arundo donax (A. donax) is a fast and naturally growing species in the Mediterranean Area indicated as one of the 15 invasive species with greatest impact by the European Commission within the Ecosystem Vulnerability Key Actrion. It is a greatly available but non-fully exploited material regarded as a problem both in agriculture and in watercourse management. This study explores the potential use of A. donax as an alternative material in the production of particleboard panels. The research, conducted in collaboration with the industrial sector, evaluates the mechanical and physical properties of sandwich particleboards in which part of the recycled wood chips are replaced with varying percentages of A. donax chips only in the core of the board. The work demonstrates the feasibility of such a board using industrial procedures and the capability of A. donax to improve the physical and mechanical performance of the recycled wood particleboard without altering the production process or adding resin. The particleboards were manufactured in three densities (550, 680 and 750 kg/m3) and tested for thickness swelling, surface soundness, internal bond and bending strength. The results reveal that particleboards containing 20-35 % of A. donax by mass, particularly for high densities, improved mechanical properties and reduced the thickness swelling, meeting the requirements for class P4 particleboards resulting in an upgrade of the wood recycled panel's classification. This investigation highlights the viability of integrating A. donax into particleboard production, potentially reducing reliance on imported wood, improving the mechanical properties of recycled wood particleboards and promoting sustainable and locally sourced materials.

Giant reed (Arundo donax L.) is a plant species with a high growth rate and low requirements, which makes it particularly interesting for the production of different bioproducts, including natural fibers. This work assesses the use of fibers obtained from reed culms as reinforcement for a high-density polyethylene (HDPE) matrix. Two different lignocellulosic materials were used: i) shredded culms and ii) fibers obtained by culms processing, which have not been reported yet in literature as fillers for thermoplastic materials. A good stress transfer for the fibrous composites was observed, with significant increases in mechanical properties; composites with 20% fiber provided a tensile elastic modulus of almost 1900 MPa (78% increase versus neat HDPE) and a flexural one of 1500 MPa (100% increase), with an improvement of 15% in impact strength. On the other hand, composites with 20% shredded biomass increased by 50% the tensile elastic modulus (reaching 1560 MPa) and the flexural one (up to 1500 MPa), without significant changes in impact strength. The type of filler is more than its ratio; composites containing fibers resulted in a higher performance than the ones with shredded materials due to the higher aspect ratio of fibers.

Arundo donax (giant reed or giant cane) is a widely available, perennial, invasive, non-food crop, present worldwide and employed for several uses, including building practices. Considering the increasing demand for sustainable building materials, A. donax can be an efficient solution. This study investigated its properties as a bio-aggregate mixed with a sodium silicate solution as an adhesive. A horizontal analysis that provided a general characterization of the composite was carried out. The results showed that the A. donax-based composite had an apparent density of 517 kg/m3, thermal conductivity of 0.128 W/(m.K), and high hygroscopicity, with a moisture buffering value of 4.33 g/(m2 %RH), property that could be both an advantage for indoor comfort and a drawback. The uncommon sound absorption behaviour can be comparable to granular materials, with the highest sound absorption coefficient values, alpha, between 600 Hz and 700 Hz. Due to the range and the shape of the acoustic absorption property, this material may be helpful in acoustic treatments for speech noise. The me-chanical tests defined flexural and compressive strength, respectively, 0.35 N/mm2 and 0.9 N/mm2, ensuring applicability. Above all, these tests opened new possible solutions for A. donax-based composite production either alone or in combination with other agro-industrial wastes and justified further tests, such as fire resistance and bio-susceptibility.