Concrete is widely used for the construction. However, the concrete production determinates a great amount of CO2 production. It is nowadays important to find waste materials to introduce in the concrete mix. In this paper it is considered the problem that every year a great amount of the wool obtained by the sheep shearing is not accepted by textile companies, because of too low quality, determinating a great ecological problem: a possible re-use of it in the concrete would be a great result in the objective of the circular economy. In this paper the intention of the author is to provide an overview of the principal mechanical properties of the concrete obtained with the addition of several percentage of sheep wool, and to find a possible optimum mix design: in fact it has found that the addition of sheep wool in the concrete mix increases the ductility of the concrete, but reduces its workability. The possibility of re-use the sheep wool in the concrete mix would be a step in the research addressed to the ecological transition of the construction sector, in the direction of a more sustainable design practice.
