Effect of various moisture content on the mechanical and viscoelastic properties of giant reed Arundo donax L.

The giant reed Arundo donax L. is an aggressive grass widely diffused throughout warm temperate regions. Thanks to its remarkable features as fast-growing, eco friendly and high specific properties (i.e. high strength/weight and modulus/weight ratios), it is widely used in ancient and traditional buildings, especially in the realization of supports for roof cladding and paneling of walls. A better understanding and a consequent standardization of its properties could make it more suitable for general application in the sustainable building industry. Mechanical and viscoelastic properties of the giant reed were studied as a function of the moisture content. To this scope, various sets of reed were considered. A first set of green reeds was collected in a Sicilian plantation. Another set was fully dried in an oven (103°C for 24 h) and finally a further set was remoistened through soaking in 5%, 10% glucose solutions and HAB (heavy alkylate benzene). For each condition investigated, samples were mechanically tested carrying out stress relaxation experiments in three points bending tests configuration, with the aim of studying the effect of moisture content on the viscoelastic properties of the giant reed. Stress relaxation experimental data were fitted using a mathematical spring pot model in order to characterize the material constitutive law and to capture the two parameter of the model ( and ). The experimental results show that it is possible to get a wide range of static (i.e. modulus, strength and ductility) and viscoelastic properties of giant reed by varying the moisture content, making it a suitable material in a wide range of semi structural applications.