anatomy of microbially induced corrosion of concrete … · 2014-07-10 · corrosion of concrete...
TRANSCRIPT
Anatomy of Microbially Induced Corrosion of Concrete Lined
Sewers
Harry R. Price, P.E. John R. Kosnak, P.E. NTH Consultants, Ltd.
Microbe succession diagram
After Microbial Ecology of Crown Corrosion in Sewers, Islander et al., ASCE Journal of Environmental Eng., V. 117, No. 6,1991
System History
• Majority constructed 1970 to 1975 • One section in late 1980’s and one section in early 2000’s • Tunnel Failures in 1978, 1980 and 2004 • Microbially Induced Corrosion (MIC) not visible in 1980’s • High levels of H2S observed during repairs 2004/2005 • Substantial MIC observed in 2006, 2007, 2008, 2010 and
2011 condition investigations
Scaling Spalling Over Reinforcing Steel
Hydraulic Jump
Reinforcing Steel
Missing Aggregate
Projecting Aggregate
Dry weather flow line
Scaling
Corrosion Product
Projecting reinforcing steel
Scaling
