TY - CONF A1 - Lorenzoni, Renata A1 - Cunningham, Patrick A1 - Fritsch, Tobias A1 - Schmidt, Wolfram A1 - Kruschwitz, Sabine T1 - Microstructure of biochar-based concrete: MIP, gas sorption, NMR, and μ-CT analysis N2 - The global demand for concrete is growing, and with it, its carbon footprint. Current literature proposes biochar, a product of pyrolysis, as a possible car-bon sink to reduce the carbon footprint of concrete. This work investigates the microstructure of Portland cement pastes with 0%, 5%, and 25% of the cement replaced with wood biochar, since this should influence its macro-scopic mechanical properties. MIP, gas sorption, NMR, and µ-CT were used to analyze the pore space of the three materials. The combination of these methods, each with different resolution, enables a multi-scale investigation of biochar impact on the microstructure of cement pastes. NMR confirmed that biochar can absorb moisture and, thus, reduces the effective water-to-cement ratio. MIP and gas sorption results show 0% and 5% volume re-placement have similar gel pore structure. The results from µ-CT investiga-tions suggest that biochar may reduce the formation of larger pores. The in-clusion of non-reactive porous particles such as biochar increase the porosity of the material and should act as a weakness in terms of mechanical proper-ties. Overall, this study highlights the need to carefully tailor replacement rates to control the impact of biochar on the microstructure concrete mixtures and sees a strong need for further studies on mechanical properties. T2 - 5th International Conference on Bio-Based Building Materials CY - Vienna, Austria DA - 20.06.2023 KW - Biochar KW - Microstructure KW - Cement KW - Porosity PY - 2023 AN - OPUS4-57948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -