Adapted Biomineralisation for municipal solid waste reuse into Concrete (AdBiCon)

Objective

The AdBiCon project will develop innovative techniques to immobilise bacteria in Municipal Solid Waste (MSW) bottom ashes for their effective reuse as precursors in alkali activated concrete (AAC). The incorporation of MSW in AAC enables the reuse of locally generated landfill waste in construction materials, offering a path to decarbonisation of the construction sector. Presently, replacing >10% Portland cement with MSW bottom ashes affords concrete with higher water demand, air content and porosity compared to Ordinary Portland cement (OPC) concrete, leading to strength loss and frequent cracks. This concrete also exhibits fast pH decline, which facilitates corrosion. This warrants for the development of new approaches to exploit bottom ashes for improved MSW-based concrete. Inspired on the Pantheon dome, biomineralisation is a nature-inspired method to strengthen, repair and protect construction materials, leveraging on bacteria-induced calcium carbonate precipitation to heal microcracks. Biomineralisation lends itself to the use of waste-derived materials as carrier and substrates for bacteria because fractional impurities and material inhomogeneity are not detrimental for the intended application. This creates a huge opportunity for waste reuse and will expand AACs enormous potential use for greener infrastructures. AdBiCon will study (1) the bacterial carrier capacity of MSW bottom ashes to protect the bacteria from a harsh environment; (2) the potential of MSW bottom ashes as bacterial nutrient medium & substrate; (3) the mechanisms of bacteria-mediated inhibition of MSW-containing concrete corrosion in comparison to reinforced OPC concrete; (4) the potential of self-healing bio-enhanced MSW concrete to prolong the service life of infrastructure, by demonstration and validation, benefitting the concrete industry. This interdisciplinary engagement with experts and stakeholders will significantly broaden the fellow's scientific skills and research portfolio.