Research on the Mechanical Properties and NMR Characteristics of Cement Mortar during Freeze-Thaw Cycles

Abstract

Low-field nuclear magnetic resonance (NMR) technology has the characteristics of nondestructive, rapid, and accurate. In the presentpaper,themechanicalpropertiesandthesizeanddistributionofporesofcementmortarduringfreeze-thawcycleswere studied by using the NMR technology for the first time. The change law of surface and quality, compressive strength, splitting tensile strength, and elastic modulus of cement mortar under 0, 25, 50, 75, and 100 freeze-thaw cycles were studied. And the changesofT2 spectraofcementmortarunderdifferentfreeze-thawenvironmentswereanalyzed;thechangerulebetweenfreezethaw cycles and the size of the pore within the cement mortar were also obtained. Moreover, the relationship between the mechanical properties and the pore structure of cement mortar was studied.