CONCRETE FREEZE THAW AS STUDIED BY MAGNETIC-RESONANCE-IMAGING/

A recently developed magnetic resonance imaging (MRI) technique is use d to study the concrete freeze/thaw process. Ice formation is spatiall y resolved in a nondestructive manner as changes in the MRI signal int ensity are observed. The phase transition temperatures are in agreemen t with published differential scanning calorimetry thermograms. The co ncrete samples were air dried for varying times. The imaging of both s aturated and non-saturated specimens demonstrates the ability to monit or non-adsorbed water in a range of pore sizes. The freeze/thaw thermo dynamic behaviour was found to depend on water content and sample hist ory. (C) 1998 Elsevier Science Ltd.