THE VISUALIZATION OF WATER TRANSPORT THROUGH HYDROPHOBIC POLYMER-COATINGS APPLIED TO BUILDING SANDSTONES BY BROAD-LINE MAGNETIC-RESONANCE-IMAGING

It is shown that broad line gradient echo magnetic resonance imaging i s an ideal tool with which to study the ingress of hydrophobic polymer surface treatments into porous building materials, specifically in th is case sandstone. It is further shown that the method can be used to quantitatively visualize the movement of water into and through the tr eated material, both from the surface and bulk, as a function of time. The influence of treatment cure time, cure temperature and substrate hydration on the subsequent water transport have been investigated. Fo r the first time direct evidence of water pumping through a treated su rface is presented.