Trade Journals for the Concrete Industry

Many researchers describe the use of biochar as a sustainable additive in concrete and as a natural lightweight aggregate for plaster, mortar and concrete as the potential main applications in the construction industry. One advantage is that biochar acts as an effective CO2 sink, which means that it can absorb and store greenhouse gas in our buildings in the long term. On the other hand, the authorised use of waste and residual wood as a source of raw materials can be seen as positive in terms of the circular economy. The present study deals with strength, water absorption and density of various types of biochar produced by technical pyrolysis. The focus was on regionally available plants: birch, beech, oak, spruce, maize, hemp and false indigo. It was shown that strength, water absorption and bulk density of the biochar varies greatly and depends on the parent material, i.e. the respective plant. Compared to lightweight aggregates made from expanded clay and expanded glass, granulated biochar seems to have a more favourable hardness-to-bulk density ratio. Biomass car- bonates from hardwood, corn cobs and false indigo provide a hard grain granule, while hemp and spruce result in soft, but light and highly porous grains.