Performance of eco-concrete made from waste-derived eco-cement

In this study, an eco-cement was synthesized primarily from municipal solid waste incineration (MSWI) residues and appraised as a stand-alone binder in concrete. In addition to thorough laboratory testing, appraisal was extended to a pilot trial involving full-scale masonry unit production. The raw feed of the contrived eco-cement was supplemented by fractional additions of calcium hydroxide (6 wt %) and sintered at a clinkering temperature of 1100 degrees C. The resulting clinker (eco-cement) demonstrated latent hydraulicity when reacted with water and strong carbonation reactivity when reacted with carbon dioxide. Carbonation curing was found to both increase and accelerate strength-yield - achieving almost 1.5 times the ultimate 90-day hydraulic strength in just one day - without compromising additional latent strength gains from subsequent hydration. The binder performance was benched against control specimens prepared from ordinary Portland cement (OPC). The study's final "eco-concrete" was activated by carbonation for early strength and further hydrated for latent strength. Eco-concrete demonstrated improved durability over conventional concrete according to surface resistivity, freeze-thaw, and drying-shrinkage evaluations. Moreover, leaching results for commonly regulated heavy metals and chlorine confirmed the environmental stability of eco-concrete according to the adopted standard testing protocol. Finally, the field pilot demonstrably validated eco-concrete's suitability as a commercial product, where manufactured full-size concrete masonry units (CMUs) met all physical and performance requirements of CSA-A165 and ASTM-C90 standards. The synthesis of eco-cement, and its use as a carbon-sequestering alternative binder in eco-concrete, holds reasonable merit for consideration as an adaptable cleaner production to improve current-day MSW incineration practice. (C) 2021 Elsevier Ltd. All rights reserved.