Study of water suction of concrete with magnetic resonance imaging methods

Abstract

Magnetic resonance imaging (MRI) methods have been applied by different authors to study water transport into porous media. So far, mostly dry samples of materials with relatively high porosities such as sandstone or limestone as well as mortars have been studied. We report the successful application of MRI techniques to study the water suction of concrete prestored under conditions of varying humidity. The proton MRI technique of SPI (single-point imaging) allowed the study ofpenetrating water in suction tests. A high rest water content made the application of these techniques to samples with higher degrees of saturation difficult. To avoid such problems a deuterium MRI technique with deuterated water as the suction liquid was used. Deuterium MRI allowed the study of the water suction of concrete samples prestored at up to 90% relative humidity. Sharp fronts of inflowing liquid were detected. The front heights were strongly dependent on the prestorage conditions of the samples.