MSWIBA-based cellular alkali-activated concrete incorporating waste glass powder

In this study, municipal solid waste incineration bottom ash (MSWIBA) and waste glass were recycled and reused to synthesize aerated or cellular alkali-activated concrete (AAAC) in order to minimize their disposal at landfills and to produce a value-added construction material. The experimental results showed that incorporating 20% waste glass powder (WGP) in the alkali-activated MSWIBA-WGP products would not cause a decrease in strength, and WGP can be considered as a precursor as well as a waste-derived activator to provide the reactive silica for geopolymerization. The MSWIBA as the main precursor contributed to the structure forming of AAAC as well as acting as a source of foaming agent due to the presence of metallic aluminium. The prepared AAAC incorporating 20% WGP exhibited low thermal conductivities ranging from 0.14 to 0.38 W/m·K with compressive strengths ranging from 0.9 to 10.4 MPa, and density values from 494 to 1295 kg/m³. The results obtained by optical photography and Scanning Electron Microscopy-backscattered electrons imaging methods showed that the prepared AAAC had less spherical air voids and wider air-void size distribution from 0.02 to 3.0 mm when compared to traditional aerated cement concrete, and the reactive silica was able to form C(N)-A-S-H which provided the mechanical strength development of AAAC.