A phenomenological approach on the influence of paramagnetic iron in cement stone on 2D T1-T2 relaxation in single-sided 1H nuclear magnetic resonance. (June 2019)

• Record Type: Journal Article
• Authors: Schulte Holthausen, Robert; Raupach, Michael
• Is Part Of: Cement and concrete research. Volume 120(2019)
• Page Start: 279
• Page End: 293
• Publication Date: 2019-06
• Subjects: B calcium-silicate-hydrate -- B characterisation -- B microstructure -- B 1H nuclear magnetic resonance; Cement -- Periodicals; Cement -- Research -- Periodicals; Concrete -- Periodicals; Concrete -- Research -- Periodicals; Ciment -- Périodiques; Béton -- Périodiques; Cement; Concrete; Periodicals; 620.135
• DOI: 10.1016/j.cemconres.2019.03.027
• Languages: English
• ISSNs: 0008-8846

Abstract

Abstract: In recent years, there has been an increasing interest in 1 H nuclear magnetic resonance (NMR) relaxometry to obtain information on the hydration and porosity of cement stone. By spin-spin ( T 2 ), spin-lattice ( T 1 ), and combined relaxation studies, new insights were gained on liquid and crystal bound water as well as pore water exchange. A conversion of relaxation times to pore sizes has been developed and shown to give consistent results. In this study, we use single-sided 1 H NMR to obtain two-dimensional T 1 - T 2 relaxation distributions on systematically varied cement stone samples as well as hydrated and solid cement phases. Results show a richness in features beyond past studies and are interpreted qualitatively in terms of water found in chemically different pore environments. Both T 1 and T 2 surface relaxivity of calcium silicate surrounded liquid water linearly correlate with the cement's Fe2 O3 content. Results are discussed based on a theory of interacting surface relaxation mechanisms.