In an attempt to increase the carbon sequestration in concrete and bring the emissions toward zero, some authors studied incorporation of larger quantities of biochar in concrete. In biochar was used at a biochar:cement mass ratio of up to 1:1 to produce low strength (> 10 MPa) blocks. In this way, 86% of the emissions could be reduced compared to a reference concrete (with 30% mass content of OPC and strength of >15 MPa). Yet, few studies in which biochar was added to concrete in larger amounts have been published and even fewer practical applications are known. This is not least due to the negative effects of large amounts of biochar on the mechanical properties and durability of concrete. Further, the fresh state properties, in particular those related to workability, are a major challenge. Due to the high porosity, high specific surface and high water absorption of biochar , its water uptake will unavoidably lead to reduced workability of the concrete . This must be compensated with higher dosages of superplasticizers. At the same time, the dosage of chemical additives (e.g. superplasticizers, air entrainers, shrinkage reducing agents) in the concrete may need to be increased if they are in part adsorbed on the surfaces of biochar.