Montgomery County Garage 49 Rehabilitation

The Garage 49 post-tensioning repair project involved the performance of major structural and waterproofing repairs to the five-level cast-in-place concrete post-tensioned structure.  The combination of poor design and construction details resulted in severe cracking and deflection of the elevated decks of the parking structure. 

The visible signs of distress led the owner, Montgomery County, to conduct a condition survey in 2004 that included physically exposing and examining a section of the post-tensioning system across a 60-ft wide section of the elevated deck from column-to-column, along a construction joint.  Exploratory work revealed areas where over 40% of the uniform cables across the slab section had failed due to structural design deficiencies and corrosion-related deterioration. 

The survey led to the installation of emergency shoring along construction joints throughout the garage until a thorough repair program could be performed.  SK&A's services included:

• Concrete repair and renovation
• Caulking and sealing
• Reinforcement repair
• Waterproofing and protection
• Capital planning and budgeting
• Project management
• Structural evaluation and repair

Highlights of the project included the installation of new pour strips along existing construction joints, while tackling unforeseen conditions and additional repairs to anchor strips and cables within almost every repair phase.  The post-tensioning cable replacement work was challenging due to temporary stressing required on sections of tendons actively being repaired to ensure that the structure could adequately support vehicular traffic and remain open and in use as the repair work was being performed. 

The project was awarded the Concrete Repair Project of the Year in 2007 by the International Concrete Repair Institute’s Baltimore-Washington Chapter.