Biochar as a cost-effective and eco-friendly substitute for binder in concrete: a review

Owing to the scarcity of raw materials and environmental concerns, concrete industry demands a suitable environment friendly material, which can substitute it partially while maintaining its required characteristics. Biochar from agricultural biomass is sustainable product for construction uses without any adverse effect on environment. It acts as effective binder/filler for enhancing performance of construction material, including mechanical/rheological properties, water absorbing capacity, insulating nature, chemical stability and environmental safety. This review presents significant aspects of biochar as additive to cementitious materials. It highlights its role in improving the performance of concrete for various applications in construction industry. It also suggests that a suitable permutation and combination is necessary for optimizing its properties and effectiveness. It can be derived from the studies carried out in this domain that on average, 1–3% addition of biochar derived from various lignocellulosic biomass can serve as optimum concentration for enhancing performance in building constituents. The review also highlights the economic viability and environmental benefits of biochar addition in cementitious composition. This article will provide deep insight and understanding about appropriateness of biochar as important constituent in construction industry. It will be encouraging for the researchers to strengthen their observations and outcomes, helping in categorizing biochar as ‘green concrete’ in upcoming time.HighlightsBiochar is an efficient binder for cement to be used for costruction/buildings.Advantages offered by it to buildings include mainly improved rheology, chemical stability, water retention ability and protection from cracks.It helps in maintaining indoor temperature of builidngs.It is an economically feasible additive for construction purpose and reduces environmental pollution by sequestring CO2.Being able to be produced from agricultural wastes, it acts as a measure to waste management also.