Water transport in concrete

Abstract

Chloride contamination is a major source of concrete deterioration. Previous studies of chloride transport use weight-vs.-time analysis on immersed samples to deduct related concrete water exchange properties, based on the assumptions of strictly capillary flow and a well defined transport front. The calculations yield substantially higher penetration depths than are found empirically. MRI was used to tomographically follow the water uptake and check the validity of these model assumptions. To eliminate background signal from enclosed water, we worked with deuterated water in combination with deuterium MRI. This approach provides evidence for a reduced water exchange depth and for its dependence on prestorage conditions, and suggests refinements to the previously used concrete model.