Cinzas de lodo de esgoto em concretos ecoeficientes: uma revisão da literatura para produção de adição mineral - temperatura de calcinação e a sua relação com a pozolanicidade - pesquisas de 2014 a 2024

Abstract

Sewage sludge produced annually worldwide exceeds 30 million tons and the inci-eration process has become the most appropriate way to manage this waste. This incinerationis capable of reducing up to 90% of the sludge volume, leaving 10% of residual ash that can beused as a partial replacement for Portland cement in concrete, contributing to the reduction of CO2emissions. This work aims to synthesize technical knowledge in the Brazilian and inter-national context, through a literature review, regarding research on sewage sludge ash in termsof the best temperatures for its calcination and production of mineral admixture, analyzing itspozzolanicity, particle diameters, and the percentages most commonly used in concretes andmortars as a substitute for Portland cement.A time frame was defined between the years 2014and 2024 for national and international papers and the following databases were used: CAPEScatalog of theses and dissertations, UFG periodicals portal, Integrated search portal of USP,CAPES periodicals portal, Brazilian Digital Library of Theses and Dissertations and Sciencedirect platform. The results showed that sewage sludge ash (SSA) is promising as a pozzolanicmaterial, due to the presence of amorphous silica and alumina. These compounds increased thereactivity of the cement paste and positively influenced the hydration kinetics, thus improvingthe mechanical properties and durability of the concrete and mortars. It is concluded that theoptimized use of sewage sludge ash can contribute to the production of eco-efficient concretesand mortars. The SSA appears promising as an interesting and beneficial alternative for theconstruction sector and for the accumulation of solid waste in cities.