Evaluation and Life Extension Recommendations for Concrete Infrastructure: Using Correct Tools

Corrosion is an inevitable process that occurs in concrete structures over time.  At a certain point in the corrosion process, however, concrete delaminates and spalls away, leaving rebars directly exposed to corrosive, salt-laden water. This increases the corrosion rate by 20 to 50 times when compared to a fresh concrete environment. Continued exposure of rebars to hostile environments results in section losses in excess of 50% of cross section.  Significant safety and reliability problems arise when this phenomenon remains undetected and unmitigated.

The time to failure of any regular reinforced concrete structure is largely affected by the corrosion of its rebars. Once concrete is contaminated with Chlorides, appropriate corrosion mitigation must be applied to prevent further section losses and to extend service life.

Corrosion had been visually identified on various reinforced concrete structures in the United States.  The Owner hired SCS to quantify the current condition, root causes, extent, and future progression of corrosion in these structures.  Various non-destructive and laboratory tests were performed to quantify the present and future corrosion condition. 

If reinforced concrete is merely patched, the corrosion rate will increase and lead to patch failure within 5 to 7 years.  Rebars in chloride contaminated concrete will also continue to corrode at increasing rates.  Without corrosion mitigation, costly replacement of reinforced concrete structures becomes necessary.

For 20 years, Siva has recommended, designed, and inspected cost effective repair/corrosion protection options to extend service life by reducing the rate of corrosion.  SCS has also recommended the locations and types of corrosion protection that would be most effective over time.

Owners are able to further understand cost effective repair and corrosion mitigation strategies and implement those methodologies into their asset management strategy.  In this presentation, SCS will outline the steps necessary for cost effective life extension of various concrete structure types.