Agri-industrial waste in sustainable concrete

Abstract

Portland cement manufacturing accounts for between 8% and 10% of global anthropogenic carbon dioxide emissions, making the search for supplementary binder materials with a lower environmental impact a priority for sustainable construction. The objective of this study was to analyze, through a systematic literature review, recent evidence on the use of agro-industrial waste ash —rice husks, sugarcane bagasse, corn cobs, olive, oil palm, coffee, wheat, peanut, coconut, and bamboo residues, among others—as partial cement substitutes in sustainable concretes and mortars. The review was conducted following the PRISMA 2020 guidelines and explicit inclusion and exclusion criteria, allowing for the qualitative evaluation of 35 studies published between 2023 and 2025, selected from 312 records identified in academic databases. The results show that agro-industrial ashes obtained through controlled calcination exhibit high pozzolanic activity due to their amorphous silica content, which promotes increased long-term mechanical strength, reduced permeability, water absorption, and chloride penetration, as well as greater durability in aggressive environments, especially with replacement rates of 5% to 20%. Summary tables are also presented on the most studied wastes and the recommended replacement ranges. Overall, the reviewed evidence indicates that agro-industrial waste constitutes a technically and environmentally viable alternative for reducing the carbon footprint of the construction sector and strengthening circular economy strategies.