The influence of biochar addition on the strength and microstructural characteristics of cement pastes

Nowadays, many branches of civil engineering begin to suffer from the lack of natural high-quality resources. The cement industry is one of the main consumers of such raw materials and, moreover, significantly contributes to global warming by the release of high amounts of carbon dioxide. In this sense, the incorporation of supplementary cementitious materials may help to reduce global environmental impacts of cement production. This paper is focused on the influence of the partial Portland cement replacement using a biochar. Basic material properties of both Portland cement and biochar were analysed. On hardened samples of cement pastes cured under water for 27 days, physical, mechanical and mineralogical properties were determined using several instrumental techniques. Experimental data showed the gradual decrease of bending and compressive strengths with the increasing replacement of Portland cement, however, significant lightening of produced pastes was achieved and thus the cement pastes additive with appropriate amounts of biochar may find usage in specific industrial applications.