Thermal and structural properties of a hemp–lime biocomposite

Abstract

The need to reduce greenhouse gases emission produced by the building sector leads to the research of renewable and less impacting materials that can replace traditional ones. This subject has encouraged new researches on biocomposite concretes with the aim to exploit renewable resources like vegetal fibres intended as materials whose production processes are generally characterized by low costs and energy demand. This biocomposite is obviously much lighter than concrete and, therefore, can be suitably used in such cases where a structure cannot be overloaded, for instance in the realization of a green covering on top of a preexistent building. In this work, a first analysis of the thermal and structural behaviour of a biocomposite concrete, constituted by a mineral matrix (lime) with the addition of vegetal fibres (hemp), has been carried out, with particular attention to the amount of fibres and its granulometry in the mixture. The drying process contemplate a permanence of the material in a thermostatic chamber. The analysis carried out shows that hemp can be used both for the realization of insulation panel (hemp fibres alone) and as a construction material (hemp bast and concrete mix). This biocomposite has shown good insulation properties and some mechanical resistance. However, the results show that further analyses should be carried out on the drying process of the material, as it can greatly influences thermal and mechanical properties.