TITLE:
Non-Destructive Imaging of Water Permeation through Cementitious Materials Using MRI
AUTHORS:
Yuya Sakai, Yuki Yokoyama, Toshiharu Kishi
KEYWORDS:
MRI, Cement Paste, Concrete, Water Permeation, Non-Destructive Testing
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.7 No.3,
August
15,
2017
ABSTRACT: In this study, water permeation through cementitious materials was observed using magnetic resonance imaging (MRI). The influence of cement type on the magnetic resonance signal was studied subsequent to determining the parameters required for imaging. Consequently, adequate imaging of water permeating through hardened cement paste (HCP) made with white Portland cement was achieved, while water permeation through ordinary Portland cement-based HCP yielded poor signal. HCPs maintained at various levels of relative humidity (RH) were observed, and the signal was detected only from those maintained at an RH of higher than 85%. The water permeation depths in HCP were observed by using MRI, and the measured depths were compared to those measured via a spraying water detector on the split surface of the specimens. As a result, good agreement was confirmed between the two methods. Additionally, MRI was applied to concrete specimens; although it was found that water was not detected when a lightweight aggregate was used, water permeation through concrete with limestone aggregate was detectable via MRI. MRI will help in understanding how water permeation causes and accelerates concrete deteriorations such as rebar corrosion and freezing and thawing.