TY - JOUR A1 - Schmidt, Wolfram A1 - Rübner, Katrin A1 - Schneider, Joachim A1 - von Werder, Julia A1 - Gluth, Gregor T1 - 63. DAfStb-Forschungskolloquium in der BAM - Themenblock 2: Nachhaltigkeitspotentiale N2 - Die Bauindustrie ist für rd. 40 % des weltweiten Energieverbrauchs und der Kohlenstoffemissionen verantwortlich. Mit der technologischen Entwicklung wird der Energiebedarf in Zukunft sinken, während sich das Problem grauer Emission verschärft. Daher ist ein verantwortungsvoller Umgang mit Ressourcen der Schlüssel zur Erreichung der Pariser Klimaziele. Der Einsatz klimaschonender Baustoffe weist dabei ein erhebliches Nachhaltigkeitspotential auf. Recycling, Rückgewinnung, Ressourcenschonung und Kreislaufwirtschaft können zu unersetzlichen Bestandteilen der Bautechnik werden. Im Folgenden werden einige Möglichkeiten vorgestellt, die bei der Dekarbonisierung der Bautechnik zukünftig hohe Potentiale aufweisen. Diese wurden beim 63. Forschungskolloquium des DAfStb an der BAM vorgestellt und Details können dem Tagungsband (DOI 10.26272/opus4-61338) entnommen werden. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Bindemittel KW - Klimaschonende Baustoffe KW - Dekarbonisierung PY - 2025 SN - 0005-9846 VL - 75 IS - 4 SP - 131 EP - 134 PB - concrete content UG CY - Schermbeck AN - OPUS4-63068 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munsch, Sarah Mandy A1 - Schmidt, Wolfram A1 - Lorenzoni, Renata A1 - Telong, Melissa A1 - Grobla, Lili A1 - Lauinger, Robert A1 - Kruschwitz, Sabine T1 - Investigation of the hydration of clinker‑reduced cementitious binders by 1H NMR relaxometry N2 - In this paper, we demonstrate the value of 1 H NMR relaxometry for studying the hydration of clinker-reduced, climate-friendly cementitious binders. Our study includes white cement (WC), ordinary Portland cement (OPC), and samples incorporating reactive agro-waste based ashes and non-reactive biochars as supplementary cementitous materials (SCM). NMR measurements were performed over a period of up to 120 h during hydration with an echo time of 50 μ s and a relatively large sample size of 20 mL. The results were compared to heat flow calorimetry (HFC) data, and a detailed comparison with literature data was performed for pure OPC and WC. The results show that time-resolved NMR measurements, especially the analysis of individual NMR signal components assigned to defined 1 H reservoirs, are effective for studying hydration processes. They offer insights into the evolution of the microstrucure and specific chemical phases. NMR provides valuable information and serves as a good complement to HFC. The comparison with data obtained with shorter echo times (40 μs or around 15–45 μs with solid echo sequence) on much smaller samples showed almost identical developments with respect to the T2 distributions. For the SCM samples, NMR results indicated partially accelerated hydration processes compared to classical OPC hydration. One SCM sample acted as a highly reactive pozzolan, showing a similar hydration process to OPC with the strongest effect observed when superplasticizer was added. Adding biochar delayed C-S-H gel pore formation but significantly increased capillary pores and even free water, likely due to the sponge-like structure. KW - Nuclear magnetic resonance relaxometry KW - Heat flow calorimetry KW - Cement KW - Hydration KW - Clinker reduction KW - Carbon emission KW - Kinetics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630284 DO - https://doi.org/10.1617/s11527-025-02632-x SN - 1871-6873 VL - 58 IS - 137 SP - 1 EP - 23 PB - Springer Nature AN - OPUS4-63028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine A1 - Munsch, Sarah Mandy A1 - Telong, Melissa A1 - Schmidt, Wolfram A1 - Bintz, Thilo A1 - Fladt, Matthias A1 - Stelzner, Ludwig T1 - The NMR core analyzing TOMograph: A multi-functional tool for non-destructive testing of building materials N2 - NMR is becoming increasingly popular for the investigation of building materials as it is a non-invasive technology that does not require any sample preparation nor causes damage to the material. Depending on the specific application it can offer insights into properties like porosity and spatial saturation degree as well as pore structure. Moreover it enables the determination of moisture transport properties and the (re-)distribution of internal moisture into different reservoirs or chemical phases upon damage and curing. However, as yet most investigations were carried out using devices originally either designed for geophysical applications or the analysis of rather homogeneous small scale (< 10 mL) samples. This paper describes the capabilities of an NMR tomograph, which has been specifically optimized for the investigation of larger, heterogeneous building material samples (diameters of up to 72 mm, length of up to 700 mm) with a high flexibility due to interchangeable coils allowing for a high SNR and short echo times (50 - 80 m s). KW - Fire spalling KW - Moisture transport KW - Concrete KW - Cement hydration KW - Sensitivity KW - Supplementary cementitous materials KW - Frost salt attack PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-573755 DO - https://doi.org/10.1016/j.mrl.2023.03.004 SN - 2097-0048 VL - 3 IS - 3 SP - 207 EP - 219 PB - Elsevier B.V. AN - OPUS4-57375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -