Preservation of Pre-Stressed Structures: Using Correct Tools to Save Costs

Corrosion of pre-stressed structures is an issue of increasing concern for Owners across the nation. Prestressing is a good method for overcoming concrete’s natural weakness in tension. However, corrosion related problems have been found to occur in less time than expected. In-depth analysis and remedial actions need to be planned and executed to avoid further damage of structures. This presentation would discuss SCS’s work on several pre-stressed structures.

Case studies will examine pre-stressed I-beams and the unique nature of corrosion in these members. Deterioration is often minimally visible through visual inspections. If in-depth analysis and preservation techniques are not utilized, further cracks and structural failure can result. SCS has used a number of specialized NDT and corrosion rate test procedures to answer “how bad is bad?” and “how long until corrosion results in potential failure?” in pre-stressed beams. SCS then proposes solutions to extend the lives of these beams.

If these problems are quantified and addressed in a timely manner, structure Owners have saved 75-80% of the cost of replacement through specialized preservation techniques.

Methodologies are also available to quickly identify significantly corroded and broken strands in-situ and assist owners in saving significant costs by addressing these problems early.

The fundamentals of corrosion problems in pre-stressed structures are different when compared to other types of structures. It is vital to find the time-to-criticality of pre-stressed structures before sudden failure occurs.  SCS has valuable experience assisting Owners with quantifying corrosion in time to properly budget and plan for rehabilitation measures.

Key Words: Pre-stressed, Corrosion, I-beam, Box beam, Remedial, Condition, Evaluation, Non-Destructive Testing.