Forensic Evaluation and Comparative Assessment of Repair Strategies for Corroded Prestressed Beam: A Florida Case Study

Prestressed concrete beams are common in both older and modern structures; however, tendon corrosion especially when construction drawings are unavailable and the effective prestress is unknown, requires engineers to diagnose damage and design repairs under significant uncertainty. This paper presents a forensic investigation and repair design for a corroded prestressed beam in a Florida parking garage, demonstrating a systematic approach that links field evidence to engineering decisions. 

The investigation included document review, condition survey, and targeted in-field testing to identify root causes and quantify the extent of deterioration. Four repair strategies were evaluated: (1) externally bonded FRP/GFRP, (2) external post-tensioning with FRP tendons, (3) in-situ repair or segmental replacement of corroded strands, and (4) supplemental mild-steel reinforcement. Each option was assessed based on key factors such as design challenges, treatment of unknown prestress, load-path compatibility, durability and corrosion protection, constructability and access, inspection and quality assurance, serviceability (deflection and cracking), and cost and schedule implications. The outcome is a practicable decision-making framework that prioritizes safety, durability, and constructability while accommodating limited information. Lessons from this Florida case study offer engineers and professionals practical guidance for evaluating and repairing corroded prestressed beams in similar field conditions.

The outcome is a practicable decision-making framework that prioritizes safety, durability, and constructability while accommodating limited information. Lessons from this Florida case study offer engineers and professionals practical guidance for evaluating and repairing corroded prestressed beams in similar field conditions.

1.5 PDHs