Non-destructive chemical analysis of water and chlorine content in cement paste using near-infrared spectroscopy

Chloride induced deterioration of concrete structures is well underway when the damage is visually detected during inspection. If such damage was identified using a non-destructive method, inspection costs would reduce significantly. We tested the use of near-infrared (NIR) spectroscopy for non-destructive multicomponent analysis of cement pastes. Cement paste samples with varying chloride ion concentrations and humidity were prepared for different cement types. Reflectance spectra were obtained, then total moisture content (v/v) and chloride ion concentrations were measured using destructive testing as a reference. A correlation was observed between the measured water amount/chloride ion concentration and respective NIR absorption values. (C) 2018 The Authors. Published by Elsevier Ltd.