Producing a siliceous material exclusively from waste incineration energy and ashes and validating its use as a mineral admixture for concrete

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This Collaborative Research and Development (CRD) project aims to produce an eco-friendly siliceous material exclusively from municipal solid waste incineration (MSWI) ashes at incineration-equivalent temperatures. The siliceous material so produced will be used as a mineral admixture to partially replace Portland cement in concrete and lend improvements to performance and durability. This project builds on the successful completion of NSERC strategic project, "turning municipal solid waste incineration into eco-bricks production", which demonstrated the viable synthesis of eco-cement from MSWI ashes at incineration-equivalent temperatures. The promising results warrant investigating real market uses for eco-cement. As a potential standalone binder in concrete, eco-cement requires carbonation activation, a curing technique that is still in its developmental stages. In addition, eco-cement is only applicable to dry-cast products, which represent only 15% of the total concrete market. Alternatively, when proportioned differently, eco-cement can be made to display cementitious or pozzolanic behavior and, therefore suited for consideration as a mineral admixture to partially replace cement in all types of concrete. This route demonstrates a larger share and easier path to market. It is well established for mineral admixtures such as coal fly ash and blast furnace slag. In fact, there has been a shortage in quality fly ash in recent years, presenting an opportunity to explore this study's eco-admixture. Such an application would expand the modified eco-cement's use to the entire concrete market. An incinerator could possibly be made autogenous, where the siliceous eco-admixture is produced locally using generated heat and ash residues. In such a scenario, an incinerator is turned into an alternative admixture supplier, thus creating a new revenue stream, and additionally benefiting from diverting hazardous ash from landfills and eliminating associated tipping fee costs. The project will focus on the novel formulation of a siliceous admixture. Validation will include comprehensive material testing specific to standards compliances, environmental stability, and long-term durability performance.