Laboratory Test and Geochemical Modeling of Cement Paste Degradation, in Contact with Ammonium Chloride Solution

Barbara Słomka-Słupik; Krzysztof Labus

doi:10.3390/ma15082930

Laboratory Test and Geochemical Modeling of Cement Paste Degradation, in Contact with Ammonium Chloride Solution

Materials (Basel). 2022 Apr 17;15(8):2930. doi: 10.3390/ma15082930.

Authors

Barbara Słomka-Słupik¹, Krzysztof Labus²

Affiliations

¹ Faculty of Civil Engineering, Silesian University of Technology, 44-100 Gliwice, Poland.
² Faculty of Mining, Safety Engineering and Industrial Automation, Silesian University of Technology, 44-100 Gliwice, Poland.

Abstract

Concrete tanks, in coke wastewater treatment plants, are exposed to aggressive wastewater with high ammonium and chloride content, deteriorating the concrete binder. Due to this, toxic compounds may migrate to the environment. The results of the experimental work presented confirmed the changes in the phase, microstructure and concentration of chlorides caused by the penetration of NH₄Cl into the hardened cement paste in dry conditions. Geochemical modeling of the interactions between the aggressive solution, the cement stone matrix and the pore water was performed in order to track the destruction process effects. The results are useful for condition assessment of the structures operating under occasional immersion.

Keywords: CEM I; ammonium chloride; cement paste degradation; chloride concentration; geochemical modeling; phases changes; porosity changes.