Microstructural investigation of Portland-limestone cement concrete with pozzolanic materials after long-term exposure to sulfate environment

0508179 - ÚTAM 2022 eng A - Abstract
Sotiriadis, Konstantinos - Mácová, Petra - Mazur, A. - Viani, Alberto - Tsivilis, S.
Microstructural investigation of Portland-limestone cement concrete with pozzolanic materials after long-term exposure to sulfate environment.
[Pan-Hellenic Conference on Chemical Engineering /12./. 29.05.2019-31.05.2019, Athens]

In the present study, identification and quantification of the phases present in samples obtained from the surface of deteriorated Portland-limestone cement concrete specimens, incorporating pozzolanic materials, was performed, after long-term exposure to sulfate solution at 5 °C, employing a combination of analytical techniques. The results indicated that thaumasite was more abundant in concrete without pozzolanic addition. Destabilization of thaumasite, occurring in concrete with natural pozzolana, was accompanied by increased gypsum and amorphous content. Metakaolin most effectively prevented C─S─H degradation. Pozzolanic materials contributed in increased mean chain length of C─(A─)S─H structures. Al substitution for Si in silicate chains was more pronounced in concrete with pozzolans.
Permanent Link: http://hdl.handle.net/11104/0327477