Recent advancements in the use of biochar for cementitious applications: A review

With increasing population and rising demands for improved built environment, there is an expected increase in greenhouse gas emission from the construction industry. Carbon dioxide emission levels are fast approaching a tipping point which could lead to irreversible climate change. The earth's capability to neutralise the CO2 emissions through the natural carbon cycle has been overstretched. Therefore it is imperative to adopt technologies that are able to capture and sequester CO2 in order to cancel out their release from industrial activities such as the construction and building industry. This is important so that cement-based material productions' carbon footprint can be reduced drastically for a positive change to take place in the climate. Biochar holds great promise as an effective CO2 sorptive material in cement-based applications relatively similar to its conventional use for soil amendment. Actually, fragmented researches on biochar as an admixture in cementitious materials have been conducted. Based on this logic, this review placed enormous emphasis on collating information from recent studies on biochars from agro-sources used as an admixture in cement-based applications. Similarly, the review gave up-to-date knowledge about the sources of the biomass and the production processes. Conclusively, the positive effects of biochar for carbon sequestration on some properties of the various cementitious applications were highlighted.