Detection of moisture and hydrogenous liquids in building materials by neutron radiography

Neutron radiography (NR) is a very useful NDT method for the determination of moisture and of hydrogenous materials in laboratory samples of porous building materials. Most of common building materials are more or less transparent to neutrons while hydrogen has a large neutron attenuation coefficient which enables a easy detection of moisture. Direct near real time neutron imaging techniques such as Imaging Plates Neutron Detectors (IP-ND) are used to record time frozen images of concentration profiles of moisture and of other hydrogenous liquids in samples of porous materials. Hydrophobation processes such as penetration and distribution of the hydrophobic materials in the porous sample, silicone resin binding and evaporation of the solvent, penetration of moisture in the treated material and verification of the hydrophobic treatment are practical problems in the building industry and in the preservation of architectural heritage which can be studied by quantitative NR.