Pathway of a damaging mechanism – Analyzing chloride attack by synchrotron based X-ray diffraction

• Published in: Solid state sciences 2015-06, Vol.44, p.45-54
• Main Authors: Schlegel, M.C., Stroh, J., Malaga, K., Meng, B., Panne, U., Emmerling, F.
• Format: Article
• Language: English
• Subjects: Binding energy; Cementitious materials; Cements; Chemical analysis; Chemical attack; Chemical compositions; Chloride attack; Chlorides; Damage; Degradation; Degradation mechanism; Diffraction; Durability; EDX; Energy dispersive spectroscopy; Energy dispersive X ray spectroscopy; High spatial resolution; In-situ; Portland cement; Sodium chloride solution; Supplementary cementitious material; Synchrotrons; X ray diffraction; X ray spectroscopy; X-rays
• ISSN: 1293-2558; 1873-3085; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2015.03.021

Typically, the changes of the phase compositions due to the chemical attack are studied in-situ only by chemical analysis or microscopy. In this study, the chloride transport and binding in the cement matrix in different cementitious materials was analyzed by synchrotron based X-ray diffraction (SyXRD) and energy dispersive X-ray spectroscopy (EDX). Sample materials consisting of cement paste were embedded in high concentrated sodium chloride solution over different time spans. Afterwards, the phase and chemical compositions were determined. The high spatial resolution and the information about the chloride distribution offer a detailed view of chloride binding in the cement matrix and allow the conclusions about the degradation mechanisms. The results are discussed related to the influence of different supplementary cementitious materials on the damaging mechanism. [Display omitted] •The chloride transport in cement matrices was analyzed based on SyXRD and EDX.•The data obtained allows understanding the degradation mechanisms.•Cement matrices containing blends show higher resistance against chloride ingress.