Session Details
[Doctoral School]Doctoral School/Dr. Maciej Zajac (Carbonation Hardening)
Sun. Sep 27, 2026 4:15 PM - 5:30 PM JST
Sun. Sep 27, 2026 7:15 AM - 8:30 AM UTC
Sun. Sep 27, 2026 7:15 AM - 8:30 AM UTC
HASEKO-KUMA Hall(Engineering Bldg11)
Dr. Maciej Zajac (Carbonation Hardening)
Lecture:
Carbonation Hardening of Cementitious Materials: Mechanisms, Performance and Industrial Boundaries
Carbonation hardening is a CO₂-curing technology in which clinker phases and early hydrates react with dissolved CO₂ to form calcium carbonate, silica-rich gels and, depending on curing history, secondary hydrate phases. This lecture introduces the mechanism from Portland cement to Portland-limestone and belitic systems. The dominant process is not ordinary hydration acceleration, but a coupled dissolution, carbonation and rehydration sequence controlled by CO₂ access, water availability, carbonate precipitation and remaining clinker reactivity. In Portland cements, alite and belite carbonation, partial C-S-H decalcification and subsequent hydrate formation refine the microstructure and improve early strength. Limestone mainly modifies carbonate availability and dilution, while belitic binders require carbonation to overcome intrinsically slow hydration. The talk will separate thermodynamic driving forces from kinetic limitations, discuss pore blocking and scale-up constraints, and evaluate where carbonation hardening is scientifically robust, industrially useful, or still unresolved for precast and low-CO₂ cement production.
Lecture:
Carbonation Hardening of Cementitious Materials: Mechanisms, Performance and Industrial Boundaries
Carbonation hardening is a CO₂-curing technology in which clinker phases and early hydrates react with dissolved CO₂ to form calcium carbonate, silica-rich gels and, depending on curing history, secondary hydrate phases. This lecture introduces the mechanism from Portland cement to Portland-limestone and belitic systems. The dominant process is not ordinary hydration acceleration, but a coupled dissolution, carbonation and rehydration sequence controlled by CO₂ access, water availability, carbonate precipitation and remaining clinker reactivity. In Portland cements, alite and belite carbonation, partial C-S-H decalcification and subsequent hydrate formation refine the microstructure and improve early strength. Limestone mainly modifies carbonate availability and dilution, while belitic binders require carbonation to overcome intrinsically slow hydration. The talk will separate thermodynamic driving forces from kinetic limitations, discuss pore blocking and scale-up constraints, and evaluate where carbonation hardening is scientifically robust, industrially useful, or still unresolved for precast and low-CO₂ cement production.