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Concrete Pressure Pipe Provides Long-Term Reliable Service — Even in Adverse Environments

Concrete Cylinder Pipe has consistently demonstrated longevity and reliability when properly installed in most natural environments. The high alkalinity of hydrated portland cement (typically ranging from 12.5 to 13.5 pH) allows for the natural formation of a protective oxide film that is maintained on the embedded steel surfaces and prevents electrochemical corrosion except in extremely adverse environments.

When CPP must be placed in adverse environments, precautionary measures may be necessary to ensure pipeline integrity. The following table identifies various conditions which may require additional measures to minimize the possibility of corrosion.

CONDITION CRITERION/CONCERN POSSIBLE SOLUTIONS
(only one solution required)
High Chlorides in Soil < 1500 Ω-cm and CI- > 400 ppm
  • Moisture barrier
  • Silica fume in exterior mortar coating or concrete
  • Corrosion inhibitor in exterior mortar coating or concrete
  • Cathodic protection if corrosion present
Stray Current Anticipated/exists
  • Supplemental dielectric coating
  • Bond + monitor
  • Cathodic protection application
High Sulfates in Soil SO42- < 2000 ppm
  • ASTM C150 Type II portland cement
SO42- > 2000 ppm
  • C3A ≤ 5% in portland cement for exterior mortar coating or concrete
  • Silica fume in exterior mortar coating or concrete
  • Barrier coating
Severe Acid Conditions In granular soils, pH < 5, and total acidity > 25 meq per 100 grams soil
  • Clay backfill
  • Calcareous backfill
  • Barrier coating
  • Silica fume in mortar coating or concrete
pH < 4
  • Clay backfill
  • Barrier coating
Atmospheric Exposure Large temperature fluctuations
Wetting & drying cycles
Solar radiation
Atmospheric carbonation
Freezing & thawing
  • Light colored barrier coating
Connection to Other Pipe Materials Disparate galvanic potentials
  • Insulating joint

 

Note: This matrix is intended to provide general guidelines for mitigating the effects of corrosion on concrete pressure pipe. Before making any design decision, you should consult your local manufacturer. To find a manufacturer in your area, contact ACPPA.

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