Utilisation of nut shell wastes in Brick, Mortar and Concrete: A review

Currently, growing activities in the construction sector have resulted in a rapid depletion of natural resources for building material production. On the other hand, agricultural industries generate a huge amount of residues/by-products every year around the world creating environmental concerns since most of these residues are burnt or disposed to the landfill. However, several current studies have presented the potential application of agricultural wastes in building material production owing to good physical and mechanical properties. Moreover, utilisation of such waste materials can contribute to reducing environmental impacts by proving alternative waste management strategies worldwide. This paper reviews some of the nut shell wastes (Argan nut, Brazil nut, Cashew nut, Groundnut, Hazelnut, Pistachio, Shea nut and Walnut) for the production of three groups of materials i.e. brick, mortar and concrete. Different properties of brick, mortar and concrete when admixed with nut shell wastes are discussed and compared with related standards. The review of literature exhibited an obvious potential of the nut shell waste as a partial replacement of conventional materials since most of the developed materials comply with the standards. However, a lack of studies on durability and thermal properties is observed. Besides, existing studies are inadequate to ascertain the potentiality of these wastes for reuse in building materials production. Therefore, extensive research is required to enhance the existing knowledge in this domain to achieve sustainable objectives in the construction industry