{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T05:17:10Z","timestamp":1769750230760,"version":"3.49.0"},"reference-count":47,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2025,6,27]],"date-time":"2025-06-27T00:00:00Z","timestamp":1750982400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Romanian Ministry of Education and Research, CNCS\u2014UEFISCDI","award":["27\/01-07-2024"],"award-info":[{"award-number":["27\/01-07-2024"]}]},{"name":"Romanian Ministry of Education and Research, CNCS\u2014UEFISCDI","award":["ERANET-M3-STF4SW"],"award-info":[{"award-number":["ERANET-M3-STF4SW"]}]},{"DOI":"10.13039\/501100006595","name":"Ministry of Research, Innovation and Digitization, CNCS\/CCCDI\u2014UEFISCDI","doi-asserted-by":"publisher","award":["27\/01-07-2024"],"award-info":[{"award-number":["27\/01-07-2024"]}],"id":[{"id":"10.13039\/501100006595","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100006595","name":"Ministry of Research, Innovation and Digitization, CNCS\/CCCDI\u2014UEFISCDI","doi-asserted-by":"publisher","award":["ERANET-M3-STF4SW"],"award-info":[{"award-number":["ERANET-M3-STF4SW"]}],"id":[{"id":"10.13039\/501100006595","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Concrete printing technologies play a key role in the modernization of construction practices. One factor that mitigates their progress is the development of standards and characterization tools for concrete during printing. The aim of this work is to point out correlations between some printability descriptors of mortars and the data obtained from low-field nuclear magnetic resonance (NMR) relaxometry techniques. In this context, the superposed effects of an acrylic-based superplasticizer and calcium nitrate accelerator were investigated. The mortars under study are based on white Portland cement, fine aggregates, and silica fume at fixed ratios. Extrusion tests and visual inspection of the filaments evaluate the extrudability and the printing window. The selected compositions were also investigated via transverse T2 and longitudinal T1 NMR relaxation times. The results indicate that both additives increase the printing window of the mortar, while the accelerator induces a faster increase in specific surface area of capillary pores S\/V only after 30\u201360 min of hydration. Some correlations were found between the printing window and the range where the transverse relaxation rates 1\/T2 and the pore surface-to-volume ratios S\/V increase linearly. This suggests some promising connections between NMR techniques and the study of structural buildup of cementitious materials.<\/jats:p>","DOI":"10.3390\/ma18133070","type":"journal-article","created":{"date-parts":[[2025,6,30]],"date-time":"2025-06-30T11:37:51Z","timestamp":1751283471000},"page":"3070","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Relations Between the Printability Descriptors of Mortar and NMR Relaxometry Data"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6760-7320","authenticated-orcid":false,"given":"Mihai M.","family":"Rusu","sequence":"first","affiliation":[{"name":"Department of Physics and Chemistry, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, Romania"},{"name":"EUT+ Institute of Nanomaterials & Nanotechnologies EUTINN, European University of Technology, European Union"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8082-6600","authenticated-orcid":false,"given":"Ioan","family":"Ardelean","sequence":"additional","affiliation":[{"name":"Department of Physics and Chemistry, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, Romania"},{"name":"EUT+ Institute of Nanomaterials & Nanotechnologies EUTINN, European University of Technology, European Union"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"106774","DOI":"10.1016\/j.cemconres.2022.106774","article-title":"Technology Readiness: A Global Snapshot of 3D Concrete Printing and the Frontiers for Development","volume":"156","author":"Ma","year":"2022","journal-title":"Cem. 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Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"134968","DOI":"10.1016\/j.conbuildmat.2024.134968","article-title":"From Pumping to Deposition: A Comprehensive Review of Test Methods for Characterizing Concrete Printability","volume":"414","author":"Fasihi","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"109719","DOI":"10.1016\/j.jobe.2024.109719","article-title":"A Comprehensive Review on Fresh and Rheological Properties of 3D Printable Cementitious Composites","volume":"91","author":"Rahman","year":"2024","journal-title":"J. Build. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.cemconres.2018.05.014","article-title":"Hydration and Rheology Control of Concrete for Digital Fabrication: Potential Admixtures and Cement Chemistry","volume":"112","author":"Marchon","year":"2018","journal-title":"Cem. Concr. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.cemconres.2018.05.011","article-title":"The Role of Early Age Structural Build-up in Digital Fabrication with Concrete","volume":"112","author":"Reiter","year":"2018","journal-title":"Cem. Concr. Res."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Roussel, N., and Lowke, D. (2022). Digital Fabrication with Cement-Based Materials, Springer International Publishing.","DOI":"10.1007\/978-3-030-90535-4"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"100012","DOI":"10.1016\/j.jmro.2021.100012","article-title":"Application of 1H Proton NMR Relaxometry to Building Materials\u2014A Review","volume":"6","author":"Nagel","year":"2021","journal-title":"J. Magn. Reson. Open"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1007\/s00723-015-0743-7","article-title":"Monitoring the Influence of Aminosilane on Cement Hydration Via Low-Field NMR Relaxometry","volume":"47","author":"Pop","year":"2016","journal-title":"Appl. Magn. Reson."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1080\/00032719.2022.2072855","article-title":"Characterization of the Influence of an Accelerator upon the Porosity and Strength of Cement Paste by Nuclear Magnetic Resonance (NMR) Relaxometry","volume":"56","author":"Rusu","year":"2023","journal-title":"Anal. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Ardelean, I. (2021). The Effect of an Accelerator on Cement Paste Capillary Pores: NMR Relaxometry Investigations. Molecules, 26.","DOI":"10.3390\/molecules26175328"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Nicula, L.M., Corbu, O., Ardelean, I., Sandu, A.V., Iliescu, M., and Simedru, D. (2021). Freeze\u2013Thaw Effect on Road Concrete Containing Blast Furnace Slag: NMR Relaxometry Investigations. Materials, 14.","DOI":"10.3390\/ma14123288"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Rusu, M.M., Vulpoi, A., Vilau, C., Dudescu, C.M., P\u0103\u015fcu\u0163\u0103, P., and Ardelean, I. (2022). Analyzing the Effects of Calcium Nitrate over White Portland Cement: A Multi-Scale Approach. Materials, 16.","DOI":"10.3390\/ma16010371"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/j.cemconres.2016.01.007","article-title":"Investigation of Early Hydration Dynamics and Microstructural Development in Ordinary Portland Cement Using 1H NMR Relaxometry and Isothermal Calorimetry","volume":"83","author":"Bligh","year":"2016","journal-title":"Cem. Concr. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"106329","DOI":"10.1016\/j.cemconres.2020.106329","article-title":"A Novel Method for Semi-Quantitative Analysis of Hydration Degree of Cement by 1H Low-Field NMR","volume":"141","author":"Liu","year":"2021","journal-title":"Cem. Concr. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"106805","DOI":"10.1016\/j.cemconres.2022.106805","article-title":"Surface Area Development of Portland Cement Paste during Hydration: Direct Comparison with 1H NMR Relaxometry and Water Vapor\/Nitrogen Sorption","volume":"157","author":"Kurihara","year":"2022","journal-title":"Cem. Concr. Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"122716","DOI":"10.1016\/j.molliq.2023.122716","article-title":"State and Role of Water Confined in Cement and Composites Modified with Metakaolin and Additives","volume":"388","author":"Papp","year":"2023","journal-title":"J. Mol. Liq."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Rusu, M.M., Faux, D., and Ardelean, I. (2023). Monitoring the Effect of Calcium Nitrate on the Induction Period of Cement Hydration via Low-Field NMR Relaxometry. Molecules, 28.","DOI":"10.3390\/molecules28020476"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Simedru, A.F., Becze, A., Cadar, O., Scurtu, D.A., Simedru, D., and Ardelean, I. (2023). Structural Characterization of Several Cement-Based Materials Containing Chemical Additives with Potential Application in Additive Manufacturing. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms24097688"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Toma, I.-O., Stoian, G., Rusu, M.-M., Ardelean, I., Cimpoe\u015fu, N., and Alexa-Stratulat, S.-M. (2023). Analysis of Pore Structure in Cement Pastes with Micronized Natural Zeolite. Materials, 16.","DOI":"10.3390\/ma16134500"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Cre\u021bu, A., Mattea, C., Stapf, S., and Ardelean, I. (2020). The Effect of Silica Fume and Organosilane Addition on the Porosity of Cement Paste. Molecules, 25.","DOI":"10.3390\/molecules25081762"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1223","DOI":"10.1007\/s00723-013-0475-5","article-title":"The Effects of Different Superplasticizers and Water-to-Cement Ratios on the Hydration of Gray Cement Using T2-NMR","volume":"44","author":"Pop","year":"2013","journal-title":"Appl. Magn. Reson."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.cemconres.2015.04.005","article-title":"Influence of Silica Fume on the Microstructure of Cement Pastes: New Insights from 1H NMR Relaxometry","volume":"74","author":"Muller","year":"2015","journal-title":"Cem. Concr. Res."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"688","DOI":"10.1063\/1.1716296","article-title":"Modified Spin-Echo Method for Measuring Nuclear Relaxation Times","volume":"29","author":"Meiboom","year":"1958","journal-title":"Rev. Sci. Instrum."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.pnmrs.2004.03.002","article-title":"Field-Cycling NMR Relaxometry","volume":"44","author":"Kimmich","year":"2004","journal-title":"Prog. Nucl. Magn. Reson. Spectrosc."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.cemconcomp.2018.12.014","article-title":"3D Printable Concrete: Mixture Design and Test Methods","volume":"97","author":"Rahul","year":"2019","journal-title":"Cem. Concr. Compos."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1109\/78.995059","article-title":"Solving Fredholm Integrals of the First Kind with Tensor Product Structure in 2 and 2.5 Dimensions","volume":"50","author":"Venkataramanan","year":"2002","journal-title":"IEEE Trans. Signal Process."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.cemconres.2016.07.012","article-title":"NMR Relaxation of Molecules Confined inside the Cement Paste Pores under Partially Saturated Conditions","volume":"89","author":"Bede","year":"2016","journal-title":"Cem. Concr. Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.micromeso.2017.09.002","article-title":"A Model for the Interpretation of Nuclear Magnetic Resonance Spin-Lattice Dispersion Measurements on Mortar, Plaster Paste, Synthetic Clay and Oil-Bearing Shale","volume":"269","author":"Faux","year":"2018","journal-title":"Microporous Mesoporous Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"033116","DOI":"10.1103\/PhysRevE.95.033116","article-title":"Nuclear-Magnetic-Resonance Relaxation Due to the Translational Diffusion of Fluid Confined to Quasi-Two-Dimensional Pores","volume":"95","author":"Faux","year":"2017","journal-title":"Phys. Rev. E"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"033117","DOI":"10.1103\/PhysRevE.95.033117","article-title":"Explicit Calculation of Nuclear-Magnetic-Resonance Relaxation Rates in Small Pores to Elucidate Molecular-Scale Fluid Dynamics","volume":"95","author":"Faux","year":"2017","journal-title":"Phys. Rev. E"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Faux, D., Kogon, R., Bortolotti, V., and McDonald, P. (2019). Advances in the Interpretation of Frequency-Dependent Nuclear Magnetic Resonance Measurements from Porous Material. Molecules, 24.","DOI":"10.3390\/molecules24203688"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"063110","DOI":"10.1103\/PhysRevE.98.063110","article-title":"Nuclear-Magnetic-Resonance Relaxation Rates for Fluid Confined to Closed, Channel, or Planar Pores","volume":"98","author":"Faux","year":"2018","journal-title":"Phys. Rev. E"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"100979","DOI":"10.1016\/j.softx.2022.100979","article-title":"3TM: Software for the 3-Tau Model","volume":"17","author":"Kogon","year":"2022","journal-title":"SoftwareX"},{"key":"ref_37","unstructured":"Kogon, R., and Faux, D. (2022, May 14). 3TM: Fitting Software for Fast Field Cycling NMR Dispersion Data. Available online: https:\/\/zenodo.org\/records\/5774107."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.cemconres.2015.07.004","article-title":"Monitoring the Size Evolution of Capillary Pores in Cement Paste during the Early Hydration via Diffusion in Internal Gradients","volume":"77","author":"Pop","year":"2015","journal-title":"Cem. Concr. Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.cemconres.2018.04.005","article-title":"Rheological Requirements for Printable Concretes","volume":"112","author":"Roussel","year":"2018","journal-title":"Cem. Concr. Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"107665","DOI":"10.1016\/j.cemconres.2024.107665","article-title":"Structural Build-up at Rest in the Induction and Acceleration Periods of Portland Cement","volume":"186","author":"Michel","year":"2024","journal-title":"Cem. Concr. Res."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Jakob, C., Jansen, D., Ukrainczyk, N., Koenders, E., Pott, U., Stephan, D., and Neubauer, J. (2019). Relating Ettringite Formation and Rheological Changes during the Initial Cement Hydration: A Comparative Study Applying XRD Analysis, Rheological Measurements and Modeling. Materials, 12.","DOI":"10.3390\/ma12182957"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"105823","DOI":"10.1016\/j.cemconres.2019.105823","article-title":"Advances in Understanding Cement Hydration Mechanisms","volume":"124","author":"Scrivener","year":"2019","journal-title":"Cem. Concr. Res."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.cemconres.2012.10.017","article-title":"1H NMR Relaxometry as an Indicator of Setting and Water Depletion during Cement Hydration","volume":"45","author":"Wang","year":"2013","journal-title":"Cem. Concr. Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1016\/j.cemconres.2011.10.005","article-title":"Change in Reaction Kinetics of a Portland Cement Caused by a Superplasticizer\u2014Calculation of Heat Flow Curves from XRD Data","volume":"42","author":"Jansen","year":"2012","journal-title":"Cem. Concr. Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"119775","DOI":"10.1016\/j.conbuildmat.2020.119775","article-title":"Structural Build-up, Hydration and Strength Development of Cement-Based Materials with Accelerators","volume":"259","author":"Yuan","year":"2020","journal-title":"Constr. Build. Mater."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"752","DOI":"10.1111\/jace.18782","article-title":"Working Mechanism of Calcium Nitrate as an Accelerator for Portland Cement Hydration","volume":"106","author":"Dorn","year":"2023","journal-title":"J. Am. Ceram. Soc."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"104152","DOI":"10.1016\/j.cemconcomp.2021.104152","article-title":"Thixotropic Structural Build-up of Cement-Based Materials: A State-of-the-Art Review","volume":"122","author":"Jiao","year":"2021","journal-title":"Cem. Concr. Compos."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/13\/3070\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:00:31Z","timestamp":1760032831000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/13\/3070"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,27]]},"references-count":47,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["ma18133070"],"URL":"https:\/\/doi.org\/10.3390\/ma18133070","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,27]]}}}