Recycling of Austrian mineral waste in alkali-activated materials (AAM) for a circular economy

In this study, relevant Austrian mineral waste streams were identified and evaluated for their potential utilization as major binder compounds in alkali activated materials (AAMs). Their chemical and mineralogical properties, including amorphous content and reactive phases, were characterized, and their fundamental reactivity was assessed through systematic mixing series at the paste level. These pastes were then tested regarding workability, visual performance, and compressive strength after 7 days. The investigated wastes (e.g., waste glass, mineral wool, construction and demolition waste, and slags) generally showed high Si but low Al contents and varied in crystallinity. The produced AAM pastes exhibited compressive strengths above 20 MPa and high waste shares up to 85 wt.-%, demonstrating the broad applicability of different mineral wastes in AAMs as a contribution towards a circular economy in the construction industry.