Towards Sustainable Cement Compositions: Exploring the Effects of Clinker Substitutes with NMR and Induced Polarization
- The reduction of clinker content in cement is a key strategy to lower the CO₂ footprint of the cement industry. In the recently approved composite cements of class CEM II, a significant portion of the clinker (up to 50%) can already be replaced. A promising option in this context is the so-called LC³ (Limestone Calcined Clay Cement), which offers exciting alternatives especially for countries with large clay deposits. To ensure the performance and durability of such binders, understanding hydration processes and the role of the used supplementary cementitious materials (SCMs) is crucial.
The authors present findings from two independent studies: a master thesis and a round-robin experiment conducted within a RILEM Technical Committee. Both studies investigate cementitious materials incorporating SCMs using advanced characterization techniques. The master thesis focuses on early hydration processes during the first 100 hours using Nuclear Magnetic Resonance relaxometry (NMR), providingThe reduction of clinker content in cement is a key strategy to lower the CO₂ footprint of the cement industry. In the recently approved composite cements of class CEM II, a significant portion of the clinker (up to 50%) can already be replaced. A promising option in this context is the so-called LC³ (Limestone Calcined Clay Cement), which offers exciting alternatives especially for countries with large clay deposits. To ensure the performance and durability of such binders, understanding hydration processes and the role of the used supplementary cementitious materials (SCMs) is crucial.
The authors present findings from two independent studies: a master thesis and a round-robin experiment conducted within a RILEM Technical Committee. Both studies investigate cementitious materials incorporating SCMs using advanced characterization techniques. The master thesis focuses on early hydration processes during the first 100 hours using Nuclear Magnetic Resonance relaxometry (NMR), providing detailed insights into microstructural development, hydrogen bonding, and water mobility. In contrast, the round-robin experiment explores hydration and durability over a longer timeframe of 3 to 91 days using induced polarization (IP) to study bulk conductivity and its changes with age. For all investigated mixtures—including pure Ordinary Portland (CEMI), Portland Limestone Cement (CEM II) including blends with calcined clay and fly ash—heat flow calorimetry serves as a reference method to monitor hydration progress during the early stages.
This approach allows a comprehensive understanding of the effects of SCMs on hydration, combining short-term and long-term perspectives while leveraging complementary techniques. Preliminary results demonstrate a significant increase in NMR T₂ relaxation times with the addition of fly ash, accompanied by a strong reduction in the free water component. Concurrently, early IP measurements reveal a steady increase in impedance with sample age, particularly pronounced in mixtures containing calcined clay. These findings underline the potential of NMR and IP to evaluate hydration and durability-related properties in cementitious systems with reduced clinker content.…


| Autor*innen: | Sabine Kruschwitz, Sarah Mandy MunschORCiD |
|---|---|
| Koautor*innen: | Lili Grobla, Wolfram SchmidtORCiD |
| Dokumenttyp: | Vortrag |
| Veröffentlichungsform: | Präsentation |
| Sprache: | Englisch |
| Jahr der Erstveröffentlichung: | 2025 |
| Organisationseinheit der BAM: | 7 Bauwerkssicherheit |
| 7 Bauwerkssicherheit / 7.4 Baustofftechnologie | |
| 8 Zerstörungsfreie Prüfung | |
| 8 Zerstörungsfreie Prüfung / 8.0 Abteilungsleitung und andere | |
| DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
| Freie Schlagwörter: | Induced polarization; Nuclear magnetic resonance; Supplementary cementitious materials |
| Themenfelder/Aktivitätsfelder der BAM: | Material |
| Material / Materialdesign | |
| Umwelt | |
| Umwelt / Circular Economy | |
| Veranstaltung: | 85. Jahrestagung der Deutschen Geophysikalischen Gesellschaft |
| Veranstaltungsort: | Bochum, Germany |
| Beginndatum der Veranstaltung: | 24.02.2025 |
| Enddatum der Veranstaltung: | 27.02.2025 |
| Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
| Datum der Freischaltung: | 28.04.2025 |
| Referierte Publikation: | Nein |
| Eingeladener Vortrag (wissenschaftliche Konferenzen): | Nein |

