BIOGENIC SULPHURIC ACID CORROSION: A MICROSCOPIC INVESTIGATION
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Published:2002
A Beeldens, J Monteny, D Van Gemert, E Vincke, N De Belie, W Verstraete, 2002. "BIOGENIC SULPHURIC ACID CORROSION: A MICROSCOPIC INVESTIGATION", Challenges of Concrete Construction: Volume 6, Concrete for Extreme Conditions: Proceedings of the International Conference held at the University of Dundee, Scotland, UK on 9–11 September 2002, Ravindra K. Dhir, Michael J. McCarthy, Moray D. Newlands
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Biogenic sulphuric acid corrosion is one of the most severe corrosion mechanisms in sewer pipes. Simulation of the tests in laboratory conditions is a demanding task due to the presence of bacteria. In this paper, the influence on the microstructure is investigated of two chemical immersion tests and a biochemical test. To ameliorate the resistance of concrete sewer pipes against biogenic sulphuric acid corrosion, polymer emulsion is added to the fresh mixture with a polymer-cement ratio of 7.5%. Analysing the eroded surface of mortar and concrete samples revealed a similar deterioration process for the different test methods. Gypsum crystals were formed preferably at places with larger porosity. However, due to the presence of bacteria, a different type of gypsum crystals was formed. A more twisted type of crystal with unsharp edges appears on the biochemical attacked specimens. The presence of polymer film results in a better retention of the attacked layer on the surface and a reduced size of the corrosion products.
INTRODUCTION
BIOGENIC SULPHURIC ACID CORROSION
TEST METHODS
MICROSTRUCTURE OF CORRODED MATERIAL
CONCLUSIONS
ACKNOWLEDGMENTS
REFERENCES
