Engineering Portland cement and concrete with agricultural-origin functional additives: Valorization of agro-waste

Decarbonization, energy and resource efficiency, and the durability of construction activities have become critical issues in addressing several UN Sustainable Development Goals, including Life Below Water, Life on Land, Climate Action, Responsible Consumption and Production, Sustainable Cities and Communities, and Industry, Innovation, and Infrastructure. The clinker, the primary constituent of Portland cement, is manufactured through a highly energy-intensive process that results in substantial CO₂ emissions. In this context, the agricultural-origin supplementary cementitious materials offer the possibility of a greener cement by partially replacing clinker and tuning the properties of Portland cement. Therefore, understanding the options of using different agricultural-origin supplementary cementitious materials is paramount. These agricultural-origin supplementary materials may include natural fibres, nanocellulose, lignin, plant extracts, agricultural waste ashes, and biochar. These are employed to partially replace clinker in Portland cement, as well as for reinforcement, fine aggregates, or other supplementary components in cement and concrete. This review article examines the applications of various agricultural-origin materials in cement and concrete, based on existing literature. It also reviews SWOT analyses and life cycle assessments, highlighting the promising environmental and economic benefits of these materials. However, the lack of standardization and supply chain inefficiencies remain significant barriers to their widespread adoption. • Clinker production is energy-intensive and contributes to CO 2 emissions. • No viable alternative to clinker, partial clinker replacement possible. • Agricultural-origin supplementary materials could replace clinker. • These are biopolymers, nanocellulose, lignin, plant extracts and biochar. • SWOT, LCA, and techno-economic assessments suggest standardization.