Monitoring durability of limestone cement paste stored at conditions promoting thaumasite formation

0535250 - ÚTAM 2021 RIV ES eng C - Konferenční příspěvek (zahraniční konf.)
Sotiriadis, Konstantinos - Hlobil, Michal - Toušek, J. - Machová, Dita - Mácová, Petra - Vopálenský, Michal - Viani, Alberto
Monitoring durability of limestone cement paste stored at conditions promoting thaumasite formation.
Current topics and trends on durability of building materials and components. Proceedings of the XV edition of the international conference on durability of building materials and components (DBMC 2020). Barcelona: International Center for Numerical Methods in Engineering (CIMNE), 2020 - (Serrat, C.; Casas, J.; Gibert, V.), s. 1039-1046. ISBN 978-84-121101-8-0.
[International Conference on Durability of Building Materials and Components (DBMC 2020). Barcelona (ES), 20.10.2020-23.10.2020]
Grant CEP: GA ČR(CZ) GJ18-26056Y
Institucionální podpora: RVO:68378297
Klíčová slova: limestone cement * thaumasite sulfate attack * microstructure * solid state NMR spectroscopy * X-Ray micro-computed tomography
Obor OECD: Materials engineering
https://doi.org/10.23967/dbmc.2020.098

The durability of Portland-limestone cement withhigh limestone content was monitored at conditions promoting thaumasite formation. Pore structure and deterioration characteristics were assessed with X-ray micro-computed tomography and correlatedwith material’s strength. Changes in crystalline and amorphous phasesof the cement paste were investigated with X-ray powder diffractionand solid state nuclear magnetic resonance spectroscopy. Rapid deterioration was observed, evolving as a front causingconcentric crack patterns followed by detachment of the part of specimen in contactwith the corrosive solution. Thisultimately led to loss of structural integrity after 4monthsofexposure.During sulfate attack, thaumasite, ettringite and gypsum formed at the expense of portlandite, calcite and monocarboaluminate hydrate. Furthermore, polymerization of silicate chains in C-S-H and deterioration of C-S-H also occurred.
Trvalý link: http://hdl.handle.net/11104/0313341