Local volcanic pozzolans from the Canary Islands as low-carbon cement substitutes: Linking microstructure, performance and CO2 reduction

Local volcanic pozzolans from the Canary Islands as low-carbon cement substitutes: Linking microstructure, performance and CO2 reduction

Článek WoS

The cement industry contributes a significant share of global CO2 emissions, positioning clinker substitution as a priority pathway for decarbonization. This study evaluates local volcanic pozzolans from the Canary Islands-both natural pyroclastic deposits and quarry residues-as supplementary cementitious materials. A comprehensive morphological and compositional characterization of the mortars was conducted using optical and scanning electron microscopies, energy-dispersive X-ray spectrometry, and X-ray diffraction and fluorescence analysis, as well as their mechanical testing. The pozzolans display trachytic-phonolitic-rhyolitic compositions with abundant zeolitic phases and amorphous content, meeting ASTM C618 Class N criteria. Mortars with up to 20 % cement replacement achieve compressive strengths above 25 MPa in line with UNE-EN 998-2, while flexural strength remains satisfactory. A cradle-to-gate assessment indicates that a 20 % clinker substitution can lower the Global Warming Potential by approximately 13.6 % per tonne of binder. The results demonstrate that valorizing local volcanic resources enables meaningful CO2 reductions without compromising structural applicability, thus supporting cleaner production in island and volcanic contexts.

The cement industry contributes a significant share of global CO2 emissions, positioning clinker substitution as a priority pathway for decarbonization. This study evaluates local volcanic pozzolans from the Canary Islands-both natural pyroclastic deposits and quarry residues-as supplementary cementitious materials. A comprehensive morphological and compositional characterization of the mortars was conducted using optical and scanning electron microscopies, energy-dispersive X-ray spectrometry, and X-ray diffraction and fluorescence analysis, as well as their mechanical testing. The pozzolans display trachytic-phonolitic-rhyolitic compositions with abundant zeolitic phases and amorphous content, meeting ASTM C618 Class N criteria. Mortars with up to 20 % cement replacement achieve compressive strengths above 25 MPa in line with UNE-EN 998-2, while flexural strength remains satisfactory. A cradle-to-gate assessment indicates that a 20 % clinker substitution can lower the Global Warming Potential by approximately 13.6 % per tonne of binder. The results demonstrate that valorizing local volcanic resources enables meaningful CO2 reductions without compromising structural applicability, thus supporting cleaner production in island and volcanic contexts.

Volcanic pozzolan, Clinker substitution, Low-carbon mortars, Circular economy, Life-cycle assessment, Cleaner production

Volcanic pozzolan, Clinker substitution, Low-carbon mortars, Circular economy, Life-cycle assessment, Cleaner production

SANTANA, J.; HERNANDEZ-GUTERREZ, L.; NUEZ, I.; LIBICH, J.; LIRIA-ROMERO, R.; SOUTO, R.

2026

26.01.2026

Elsevier

Journal of Cleaner Production

541

1

Spojené státy americké

1

14

14

https://www.sciencedirect.com/science/article/pii/S0959652626000703

http://hdl.handle.net/11012/256537