This research explores the potential of foamed concrete as a low-carbon building material by leveraging its unique pore structure to actively sequester CO₂. Foamed concrete, characterized by its lightweight, low-density, high thermal insulation, and fire-resistant properties, incorporates air voids through foaming agents, enhancing its adaptability for various applications. This study focuses on active carbonation processes in Portland cement-based foamed concrete and alternative low-carbon binder systems, such as magnesium oxychloride (MOC) and limestone calcined clay cement (LC3), aiming to establish carbon-neutral building materials. To maximize carbonation efficiency, the high porosity of foamed mineral binders is strategically utilized to accelerate and enhance CO₂ absorption, contrasting with slower carbonation rates in compact materials with lower porosity.

A-COMBS entails experimental evaluation of active carbonation’s effects on the phase composition and mechanical properties of these binders, supported by computer-based geometric pore characterization. Specifically, the research investigates carbonation in physically foamed binders with varied bulk densities and age ranges, enhancing pore connectivity with biochar particles to improve gas permeation and early hardening while mitigating structural damage from CO₂ permeation pressures. Advanced µCT and microscopic analyses as well as multi-physical finite element modeling are employed to simulate gas permeation and carbonation dynamics. These efforts culminate in a numerical material description for porous binder carbonation, informing the engineering of effective, scalable CO₂ sequestration processes in permeable building materials and advancing sustainable solutions in building material design in response to global climate challenges.

Applicants: Mechtcherine, TU Dresden