Attack of aggressive carbon dioxide on hardened Portland and blast furnace slag cement paste

Publikationstyp
Conference Paper
Publikationsdatum
2023
Sprache
English
Author
Wagemann, Falk orcid-logo
Baustoffe, Bauphysik und Bauchemie B-3 
Schmidt-Döhl, Frank orcid-logo
Baustoffe, Bauphysik und Bauchemie B-3 
Rahimi, Amir 
Federal Waterways Engineering and Research Institute, Karlsruhe, Germany
Herausgeber*innen
Bondini, F.
Frangopol, D.M.
TORE-URI
https://hdl.handle.net/11420/45243
Start Page
3468
End Page
3475
Citation
The 8th International Symposium on Life-Cycle Civil Engineering (IALCCE 2023)
Contribution to Conference
The 8th International Symposium on Life-Cycle Civil Engineering, IALCCE 2023 
Publisher DOI
10.1201/9781003323020-424
Scopus ID
2-s2.0-85186700719
Publisher
CRC Press Boca Raton
Natural groundwater and soil can contain substances which are aggressive to concrete and cement-based structures. Especially aggressive carbon dioxide occurs frequently. Chemical attack by aggressive carbon dioxide occurs in several phases in commercial cements used in foundation engineering. After a period of carbonation a leading front where calcium hydroxide is dissolved, depending on the availability in the binder matrix, is generated. As the attack progresses, the calcium carbonate formed is dissolved, leaving a layer rich in amorphous silicon dioxide, which has lower mechanical strength. This can result in problems in the long-term load-bearing behavior of more sensitive components with smaller dimensions and under tensile stress, in particular ground anchors and micro piles, which are manufactured using cement suspensions in the subsoil. This study evaluates the mechanisms induced by aggressive carbon dioxide in CEM III/A and CEM III/B compared with CEM I paste. Cement paste specimen with water-cement ratios of 0.4 and 0.5 stored in about 90 mg/l (exposure class XA2) aggressive CO2
for 3, 6 and 12 months are investigated. The methods include X-Ray fluorescence analysis as well as polarized light microscopy on thin sections. The depth of impact is measured and evaluated in terms of durability of geotechnical elements.
DDC Class
690: Building, Construction