Earth-fiber mixes for natural building products

The paper deals on an experimental research led at DICAAR_Dipartimento di Ingegneria Civile, Ambientale e Architettura of the University of Cagliari (Italy) on natural composite materials based on earth and vegetable fibers. The research is mainly aimed at the study and development of new building elements: finishing plasters and thermal/acoustic insulation panels to be used for the retrofitting of historic buildings. Some preceding experimentations conducted by the same research group were concentrated on mixes of different fibers (straw, hemp, rice husk, loofah and jute) mixed with clayey earth. Panels produced with the different fibers resulted to be very promising products for thermal and acoustic insulation. The current experimentation concerns the mixture of two types of cellulose flakes, resulting from industrial production, with a local earth. The two types of cellulose used for the experimentation come from a recycling process of newspapers. The first type is in raw form; the second one has undergone a whitening process. The tests were aimed at evaluating the characteristics of aesthetic, porosity and resistance to water contact of the samples. The obtained results offer encouraging bases for the development of innovative and efficient natural plaster mixes, to be used both for historic and new buildings.