کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
259483 | 503636 | 2011 | 10 صفحه PDF | دانلود رایگان |
Deterioration of concrete in cooling tower basins by microbiologically influenced corrosion (MIC) is a concern in geothermal power plants. The effect of supplementary cementitious materials, epoxy coatings, latex-modified mortars and calcium aluminate cement mortar for protecting concrete from MIC was investigated. Laboratory exposure tests to a particular type of sulphur and iron oxidising bacteria, Thiobacillus ferrooxidans, were performed to rank candidate materials and these were followed by field exposure tests of the best materials in a cooling tower basin. It was determined that partial replacement of cement with 40% blast furnace slag or 5% to 10% silica fume improved resistance to MIC. A replacement level of 60% slag resulted in similar performance to concrete made with ordinary Portland or sulphate resistant cement. Epoxy- and styrene butadiene latex-modified mortars offered protection to concrete but still underwent a degree of attack. Epoxy coatings were found to be effective in protecting concrete. Calcium aluminate cement mortar showed excellent durability in laboratory and field tests.
► Investigated means of protecting concrete against acid produced by sulphur oxidising bacteria in geothermal power plants.
► Studied influence of partial replacement of cement with silica fume or blast furnace slag in resistance to bacteria.
► Studied suitability of epoxy coatings, latex-modified mortars and calcium aluminate cement mortar for protecting concrete.
► Found that silica fume, epoxy coatings and calcium aluminate cement mortar offered best protection.
Journal: Construction and Building Materials - Volume 25, Issue 10, October 2011, Pages 3893–3902