Wet front penetration with unsteady state wicking in mortar studied by Magnetic Resonance Imaging (MRI)

摘要: The movement of water or carrying aggressive ions is one the leading causes deterioration concrete structures worldwide. Moisture profiles during unsteady state wicking were determined by dimensional magnetic resonance imaging 10 cm mortar specimens. Bulk free induction decay and T 2 lifetime mapping results show a bi-exponential behavior MR signal lifetime, , in all samples, indicating at least two different populations. From mapping, short assigned to interlayer (water between C–S–H layers), its associated amplitude are constant along sample. long amplitude, related pore space (micro macropores), change with local moisture content. To best our knowledge, this first time that has been spatially resolved MRI cement-based materials. Gravimetric sorptivity measurements regimes absorption four samples studied. In regime, capillary transport mechanism dominant filling macropores. second interaction solid matrix postulated cause swelling reduction rate. After swelling, diffusion controls filling. Water front penetration observed imaging, bulk showed changes can be linked from an initial secondary regime. Inverse modelling was conducted extract properties, using Hydrus program one-dimensional content profiles. Modelling decrease saturated hydraulic conductivity exposure time.