Repair of Existing Post-Tensioned Structures-Repair of Existing Post-Tensioned Structures

Video Transcription

Video Summary

The Post-Tension Institute's December 2025 webinar, moderated by Kyle Boyd, featured Scott Greenhouse, chair of PTI's repair, rehabilitation, and strengthening committee. The session focused on repairing unbonded post-tensioned concrete structures, a frequently requested topic. Scott emphasized the importance of a skilled repair team, including an experienced licensed design professional and contractor, and outlined design and safety considerations. He detailed various repair strategies such as selective tendon abandonment, tendon repair, supplementation, replacement, and full segment replacement, supported by PTI’s guide DC80.3 and specification DC80.4.<br /><br />Safety protocols during detensioning and demolition were highlighted, including exclusion zones to prevent accidents from explosive tendon releases. The webinar covered methods to locate tendons before concrete removal and cautioned against hydro demolition due to potential water intrusion causing corrosion. Techniques for tendon splicing, anchorage repairs, and re-tensioning were explained, along with durability improvements through encapsulation and waterproofing.<br /><br />Scott also discussed strengthening existing structures using active external post-tensioning systems, emphasizing fireproofing needs. The session concluded with a reminder on project documentation and the importance of integrated planning among owners, engineers, and contractors for successful repairs. Attendees were encouraged to access PTI’s extensive resources and future webinars scheduled for early 2026.

Keywords

Post-Tension Institute

unbonded post-tensioned concrete

repair strategies

tendon abandonment

safety protocols

detensioning and demolition

tendon splicing and re-tensioning

external post-tensioning systems

project documentation and planning