Award of Merit: Parking Structures Category
6th Street Parking Garage Restoration
Submitted by Sika Corporation
Parking Authority of
Kansas City, Missouri
Schnell Contractors, Inc.
Lyndhurst, New Jersey
Condition Analysis of Parking Garage Prior to Construction
Material Service Life Company
Monitoring Company of Corrosion Inhibitor Performance
C-Probe Technologies Ltd.
Lutterworth, United Kingdom
The 6th and Main Street Parking Garage, built in 1987 with a south bay addition in 1990, is a nine-level,cast-in-place, post-tensioned structure began showing signs of severe distress. A structural analysis showed the cause of the spalling to be the result of high chloride content at the level of reinforcing. Many areas that were previously repaired remained intact, but other spalls had also developed. The future appeared to be an ongoing battle against corrosion, knowing that high chloride levels were already present in the concrete but had not yet penetrated the steel reinforcement depth. The condition analysis offered a unique perspective on understanding and controlling the corrosion. Future prediction models allowed the owner to choose the repair strategy with an estimated benefit in terms of service life.
Restoration materials and methods included the use of bonding agents, repair mortars, joint sealants and membranes, corrosion inhibitors, sealers, and traffic deck membrane technologies. Because the use of an anodic and cathodic mixed corrosion inhibitor offered an excellent cost-to-benefit ratio, a measurement tool was required to understand its effectiveness. Knowledge of the corrosion inhibitor’s past performance was readily available through the manufacturer’s test results and various projects and field trials, but understanding the corrosion activity was very important. What will the corrosion activity look like after the corrosion inhibitor is applied, after six months, a year, two years, and further down the life of the structure? A state-of-the-art monitoring program would show the results of the corrosion inhibitor over a 2 year period by testing programs in 6 month intervals.