Experimental research on mechanical properties of biochar-added cementitious mortars

In recent years, biochar, the solid by-product resulting from biomass pyrolysis or gasification, has been mainly studied and applied as soil amendment, while research on its application as a building material is still scanty. The rising interest in this context is mainly related to the chance of reducing the emission of greenhouse gases that have serious environmental impacts and are responsible for the climate change. Since biochar is mainly composed by carbon, the aim is to obtain smart materials able to capture and store carbon in buildings for decades in a stable form. This paper aims to prove the feasibility of using biochar derived from agro-forestry waste residues as carbon sequestrating additive in cement mortar, by adding it, during mixing, at 1% by weight of cement. In order to assess the efficiency of biochar-added mortar as building material, its mechanical properties have been properly investigated; the results show that the addition of char in the admixture leads to comparable compressive strength, flexural strength, toughness and ductility with respect to traditional cement mortars.