Abstract

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 arc practical problems in the building industry and in the preservation of architectural heritage which can be studied by quantitative NR.

Keywords: Neutron radiography, imaging plate neutron detectors, building materials, porous materials, ceramics, moisture content, moisture transport, hydrogenous liquids, hydrophobic treatment

Source: Conference Proceedings of the 4th International Conference of the Slovenian Society for Nondestructive Testing, 24 - 25 April 1997, Ljubljana, Slovenia.
Pages:151 - 158

Publisher:
Slovenian Society for Nondestructive Testing, Faculty of Mechanical Engineering, Askerceva 6, SLO 1000 Ljubljana, Slovenia. Tel +386 61 177 12 03, Fax +386 61 218 567, Email: janez.grum@fs.uni-lj.si.