Synthese en verwerkingsroutes van poreuze materialen uit ijzerrijke slakken

This doctoral research explores the development of lightweight porous alkali-activated materials (AAM) using Fe-rich slags as their main precursor, providing a valorisation pathway for these metallurgical by-products. The study focused on understanding how synthesis routes, mix design parameters, and curing conditions influence porous morphological characteristics—including total porosity, pore size distribution, pore shape, and pore spacing—and how these features affect the resulting material performance. Key contributions include: (i) developing Fe-rich slag-based porous AAM (400-1200 kg/m³) with controlled pore structures and establishing structure-property relationships linking processing, morphology, and performance (mechanical, thermal, acoustic, and fire resistance); (ii) elucidating the role of hydrothermal curing in promoting crystalline phase formation (e.g., analcime, C-S-H), governed by slag chemistry, fineness, and processing conditions, thereby enhancing long-term stability; and (iii) introducing a fibre-stabilised alkali-based mechanical foaming route that enables higher technology readiness levels and validation in passive fire protection applications. The materials achieved low thermal conductivity values (0.08-0.18 W/m·K), sound absorption coefficients above 0.7 at mid-to-high frequencies, and demonstrated fire resistance of 180 min under ISO 834 and 270 min under EN 13381-3, comparable to commercial benchmarks. Together, these findings highlight opportunities and limitations in Fe-rich slag valorisation, offering new insights into the design of resource-efficient porous AAM for sustainable and fire-safe construction.