A BROAD-LINE NMR AND MRI STUDY OF WATER AND WATER TRANSPORT IN PORTLAND-CEMENT PASTES

The results of a magnetic resonance spin-spin relaxation analysis and broad-line magnetic resonance imaging (MRI) (gradient-echo and stray-h eld imaging) study of water and water transport in Portland cement pas tes are presented. The effect of varying the cure conditions and the w ater to cement (w/c) ratio of the sample mix are discussed. The water sorptivity and the concentration dependence of the hydraulic diffusion coefficient are calculated for samples prepared with a 0.5 w/c ratio and, therefore, an open pore structure. In the case of 0.3 w/c ratio s amples, little water transport is observed, and a closed pore structur e is inferred. (C) 1998 Elsevier Science Inc.