The structural assessment that was conducted revealed significant deterioration throughout the post-tensioned concrete system of the Montgomery College Parking Garage. Corrosion was especially severe near construction joints, where many tendons had been compromised. The most critical issue was on the fourth floor, where a slab had sagged approximately one inch along the length of a joint.

Several areas were deemed unsafe for public access and required immediate attention. Cracks and joint failures were widespread, with visible water leakage indicating that sealants had failed. Some beams also showed cracking that needed repair. On the fourth floor, broken strands were identified and eventually replaced as part of the restoration process.

Time Constraints

To minimize disruption to students at Montgomery College, all work was scheduled during the summer break.

The garage, which measures approximately 233 by 217 feet with post-tensioned slab spans of about 52 feet and floor-to-floor heights of 8.9 feet, required careful planning and execution.

Waterproofing and Structural Reinforcement

To protect the structure from future water damage, a silane sealer was applied to the deck slabs, and new drainage systems were installed. Over a three-month period, the garage remained closed to the public while crews opened sections of concrete to de-stress and lock off existing PT tendons. New tendons and intermediate anchors—also known as “dog-bones”—were installed and stressed back to full capacity. Repairs were carried out across all levels of the garage, including columns and deck slabs.