Nuclear magnetic resonance as a tool for the characterization of concrete in different stages on its development

Nuclear magnetic resonance (NMR) offers a variety of possiblities for the non-destructive characterisation of mortar or concrete. In each stage of its "life", the material properties of concrete are close connected with moisture. At the earliest stage of concrete development, NMR-methods are suitable to evaluate the degree and the velocity of hydration of cement pastes and quantitatively distinguish different molecular binding states of water. On cemented concrete, NMR-measurement results show the possibility to determine the amount of adsorbed moisture with high accuracy of the water/cement ratio of concrete. In addition there are first results which indicate the possibility to evaluate the pore size distributionand the permeability in porous materials with NMR.