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So much innovations have ensued in the concrete industry in the last decade, especially in terms of ensuring concrete sustainability and its green initiatives. A call for sustainability is imminent in the industry as the production of ordinary Portland cement (OPC) which is the main binder of concrete contributes about 8% to the world's human-induced carbon dioxide emission. In addition, the production of concrete has posed a huge threat on natural deposits of raw materials. With billions of tons of concrete expected to be produced in the coming years to meet our infrastructure demand, it is critical for other alternatives to be considered for concrete production. Such alternatives mostly fit as partial or total replacement of OPC and aggregates. This paper explored the sustainable advantage of alkali-activated binders, supplementary cementitious materials, and recycled materials as raw materials in concrete. This short review has shown that it is possible to achieve a greener concrete with enhanced properties compared to the conventional concrete with the use of new materials. Also, on the ground of economic importance, the new materials were found to have better performance than the conventional ones.

With in creas ing pop u la tion and ris ing de mands for im proved built en vi ron ment, there is an ex pected in crease in green house gas emis sion from the con struc tion in dus try. Car bon diox ide emis sion lev els are fast ap proaching a tip ping point which could lead to ir re versible cli mate change. The earth's ca pa bil ity to neu tralise the CO 2 emis sions through the nat ural car bon cy cle has been over stretched. There fore it is im per a tive to adopt technolo gies that are able to cap ture and se quester CO 2 in or der to can cel out their re lease from in dus trial ac tiv ities such as the con struc tion and build ing in dus try. This is im por tant so that ce ment-based ma te r ial pro ductions' car bon foot print can be re duced dras ti cally for a pos i tive change to take place in the cli mate. Biochar holds great promise as an ef fec tive CO 2 sorp tive ma te r ial in ce ment-based ap pli ca tions rel a tively sim i lar to its con ven tional use for soil amend ment. Ac tu ally, frag mented re searches on biochar as an ad mix ture in ce men titious ma te ri als have been con ducted. Based on this logic, this re view placed enor mous em pha sis on col lat ing in for ma tion from re cent stud ies on biochars from agro-sources used as an ad mix ture in ce ment-based ap pli cations. Sim i larly, the re view gave up-to-date knowl edge about the sources of the bio mass and the pro duc tion processes. Con clu sively, the pos i tive ef fects of biochar for car bon se ques tra tion on some prop er ties of the var ious ce men ti tious ap pli ca tions were high lighted.