Quantification of microstructural changes in limestone cement paste stored in sulfate environment at low temperature

0532112 - ÚTAM 2021 RIV CH eng C - Conference Paper (international conference)
Sotiriadis, Konstantinos - Hlobil, Michal - Machová, Dita - Mácová, Petra - Viani, Alberto - Vopálenský, Michal
Quantification of microstructural changes in limestone cement paste stored in sulfate environment at low temperature.
Solid State Phenomena. Vol. 309. Baech: Trans Tech Publications, 2020 - (Nenadálová, Š.; Johová, P.), s. 3-7. ISBN 978-3-0357-1668-9. ISSN 1012-0394. E-ISSN 1662-9779.
[International Conference Concrete Days /26./. Hradec Králové (CZ), 20.11.2019-21.11.2019]
R&D Projects: GA ČR(CZ) GJ18-26056Y
Institutional support: RVO:68378297
Keywords : limestone cement * sulfates * microstructure * X-ray tomography
OECD category: Materials engineering
Method of publishing: Limited access
https://doi.org/10.4028/www.scientific.net/SSP.309.3

Portland-limestone cement paste specimens were stored in magnesium sulfate solution at 5°C for 6 months, the occurring microstructural changes have been monitored on a monthly basis. Extent of deterioration was quantitatively assessed with different techniques. The X-ray microcomputed tomography was employed to describe non-invasively the pore structure and extend of deterioration. X-ray powder diffraction and infrared spectroscopy were used to characterize the phase changes occurred in the course of the sulfate attack. Compressive strength tests reflected the effect of the process on mechanical performance. The results indicate the rapid degradation of the system, owing, mainly, to crack formation, expansion, and finally loss of cohesion between the deteriorated parts of the specimens and the sound cement matrix, as a consequence of the formation of new phases. The progress of an irregular deterioration front was observed. The presence of complex phases (thaumasite, ettringite) was proved, however, the deteriorated parts of the specimens mostly consisted of gypsum.
Permanent Link: http://hdl.handle.net/11104/0310718