Effect of sheep wool fibres on thermal-insulation and mechanical properties of cement matrix

The use of sheep wool as reinforcement of cement in order to produce mortar or plaster involves several advantages for environment and energy. Moreover, in several regions it is treated as a waste and, consequently, its employ is characterized by low cost. Aim of this paper is to evaluate the influence of wool fibres on thermal conductivity and mechanical properties of cement. The samples were prepared using wool fibres, obtained from a breed of Sicilian sheep, with three different length (i.e. 1 mm, 6 mm and 20 mm). Moreover, in order to evaluate the influence of fibre content, the samples were prepared by varying the fibres weight fraction up to maximum level. The thermal conductivity of samples was analyzed by using a heat flow meter, whereas the mechanical behavior was studied through compressive tests. In order to validate the thermal measurements, two theoretical models were applied. The results showed that wool fibres could be considered as a valid reinforcement in cementitious matrix to obtain mortars or plasters with both enhanced thermal insulation properties and good mechanical ones.