What is the surface specific area of porous cement-based material? A nuclear magnetic relaxation dispersion approach.
We propose a new NMR method to measure and follow the evolution of the surface specific area, Sp, of a porous cement-based material. This method, that does not require any preliminary drying process, uses nuclear magnetic relaxation dispersion (NMRD), the measurement of spin-lattice relaxation rate as a function of magnetic field strength or nuclear Larmor frequency. The method is applied for three different mortars samples prepared by mixing cement, sand, silica fume, water and superplasticizer with a water to cement ratio w/c=0.25, 0.38 and 0.65, respectively. The evolution of Sp grows linearly with the degree of advancement of chemical reactions measured by thermal heating and we evidence two relaxation processes independent of the w/c ratio.
Barberon
F
F
Laboratoire de Physique de la Matière Condensée, UMR 7643 du CNRS, Ecole Polytechnique, 91128 Palaiseau, France.
Korb
J-P
JP
Petit
D
D
Morin
V
V
Bermejo
E
E
D003252:Construction Materials / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D016062:Porosity; D013499:Surface Properties